|
Cell free inhibiting activity against Streptococcus pneumoniae 5635(Wild type ribosomes for transcription/translation assay)
|
Streptococcus pneumoniae
|
170.0
nM
|
|
Journal : J. Med. Chem.
Title : Novel erythromycin derivatives with aryl groups tethered to the C-6 position are potent protein synthesis inhibitors and active against multidrug-resistant respiratory pathogens.
Year : 2001
Volume : 44
Issue : 24
First Page : 4137
Last Page : 4156
Authors : Ma Z, Clark RF, Brazzale A, Wang S, Rupp MJ, Li L, Griesgraber G, Zhang S, Yong H, Phan LT, Nemoto PA, Chu DT, Plattner JJ, Zhang X, Zhong P, Cao Z, Nilius AM, Shortridge VD, Flamm R, Mitten M, Meulbroek J, Ewing P, Alder J, Or YS.
Abstract : A novel series of erythromycin derivatives has been discovered with potent activity against key respiratory pathogens, including those resistant to erythromycin. These compounds are characterized by having an aryl group tethered to the C-6 position of the erythronolide skeleton. Extensive structural modification of the C-6 moiety led to the discovery of several promising compounds with potent activity against both mef- and erm-mediated resistant Streptoccoccus pneumoniae. Preliminary mechanistic studies indicated that the new macrolides are potent protein synthesis inhibitors, which interact with methylated ribosomes isolated from resistant organisms. In experimental animal models, these compounds exhibited excellent in vivo efficacy and balanced pharmacokinetic profiles.
|
Antimicrobial activity against Naegleria fowleri Lee (M67) at day 2
|
Naegleria fowleri
|
2.6
nM
|
|
Journal : Antimicrob. Agents Chemother.
Title : Synergistic activities of azithromycin and amphotericin B against Naegleria fowleri in vitro and in a mouse model of primary amebic meningoencephalitis.
Year : 2007
Volume : 51
Issue : 1
First Page : 23
Last Page : 27
Authors : Soltow SM, Brenner GM.
Abstract : Naegleria fowleri is responsible for producing a rapidly fatal central nervous system infection known as primary amebic meningoencephalitis (PAM). To date, amphotericin B, an antifungal agent, is the only agent with established clinical efficacy in the treatment of PAM. However, amphotericin B is not always successful in treating PAM and is associated with severe adverse effects. We previously found azithromycin to be more effective than amphotericin B in a mouse model of PAM. We therefore investigated the combination of amphotericin B and azithromycin in vitro and in a mouse model of PAM. For the in vitro studies, 50% inhibitory concentrations were calculated for each drug alone and for the drugs in fixed combination ratios of 1:1, 3:1, and 1:3. We found amphotericin B and azithromycin to be synergistic at all three of the fixed combination ratios. In our mouse model of PAM, a combination of amphotericin B (2.5 mg/kg of body weight) and azithromycin (25 mg/kg) protected 100% of the mice, whereas amphotericin B alone (2.5 mg/kg) protected only 27% of mice and azithromycin alone (25 mg/kg) protected 40% of mice. This study indicates that amphotericin B and azithromycin are synergistic against the Lee strain of N. fowleri, suggesting that the combined use of these agents may be beneficial in treating PAM.
|
Antimicrobial activity against Naegleria fowleri Lee (M67) at day 3
|
Naegleria fowleri
|
3.1
nM
|
|
Journal : Antimicrob. Agents Chemother.
Title : Synergistic activities of azithromycin and amphotericin B against Naegleria fowleri in vitro and in a mouse model of primary amebic meningoencephalitis.
Year : 2007
Volume : 51
Issue : 1
First Page : 23
Last Page : 27
Authors : Soltow SM, Brenner GM.
Abstract : Naegleria fowleri is responsible for producing a rapidly fatal central nervous system infection known as primary amebic meningoencephalitis (PAM). To date, amphotericin B, an antifungal agent, is the only agent with established clinical efficacy in the treatment of PAM. However, amphotericin B is not always successful in treating PAM and is associated with severe adverse effects. We previously found azithromycin to be more effective than amphotericin B in a mouse model of PAM. We therefore investigated the combination of amphotericin B and azithromycin in vitro and in a mouse model of PAM. For the in vitro studies, 50% inhibitory concentrations were calculated for each drug alone and for the drugs in fixed combination ratios of 1:1, 3:1, and 1:3. We found amphotericin B and azithromycin to be synergistic at all three of the fixed combination ratios. In our mouse model of PAM, a combination of amphotericin B (2.5 mg/kg of body weight) and azithromycin (25 mg/kg) protected 100% of the mice, whereas amphotericin B alone (2.5 mg/kg) protected only 27% of mice and azithromycin alone (25 mg/kg) protected 40% of mice. This study indicates that amphotericin B and azithromycin are synergistic against the Lee strain of N. fowleri, suggesting that the combined use of these agents may be beneficial in treating PAM.
|
Antiproliferative effect against primary human osteoblasts assessed as BrdU incorporation into DNA after 48 hrs
|
Homo sapiens
|
25.0
ug.mL-1
|
|
Journal : Antimicrob. Agents Chemother.
Title : Influence on mitochondria and cytotoxicity of different antibiotics administered in high concentrations on primary human osteoblasts and cell lines.
Year : 2007
Volume : 51
Issue : 1
First Page : 54
Last Page : 63
Authors : Duewelhenke N, Krut O, Eysel P.
Abstract : Osteomyelitis, osteitis, spondylodiscitis, septic arthritis, and prosthetic joint infections still represent the worst complications of orthopedic surgery and traumatology. Successful treatment requires, besides surgical débridement, long-term systemic and high-concentration local antibiotic therapy, with possible local antibiotic concentrations of 100 microg/ml and more. In this study, we investigated the effect of 20 different antibiotics on primary human osteoblasts (PHO), the osteosarcoma cell line MG63, and the epithelial cell line HeLa. High concentrations of fluoroquinolones, macrolides, clindamycin, chloramphenicol, rifampin, tetracycline, and linezolid during 48 h of incubation inhibited proliferation and metabolic activity, whereas aminoglycosides and inhibitors of bacterial cell wall synthesis did not. Twenty percent inhibitory concentrations for proliferation of PHO were determined as 20 to 40 microg/ml for macrolides, clindamycin, and rifampin, 60 to 80 microg/ml for chloramphenicol, tetracylin, and fluoroquinolones, and 240 microg/ml for linezolid. The proliferation of the cell lines was always less inhibited. We established the measurement of extracellular lactate concentration as an indicator of glycolysis using inhibitors of the respiratory chain (antimycin A, rotenone, and sodium azide) and glycolysis (iodoacetic acid) as reference compounds, whereas inhibition of the respiratory chain increased and inhibition of glycolysis decreased lactate production. The measurement of extracellular lactate concentration revealed that fluoroquinolones, macrolides, clindamycin, rifampin, tetracycline, and especially chloramphenicol and linezolid impaired mitochondrial energetics in high concentrations. This explains partly the observed inhibition of metabolic activity and proliferation in our experiments. Because of differences in the energy metabolism, PHO provided a more sensitive model for orthopedic antibiotic usage than stable cell lines.
|
Inhibition of metabolic activity in primary human osteoblasts assessed as MTT reduction after 48 hrs
|
Homo sapiens
|
160.0
ug.mL-1
|
|
Journal : Antimicrob. Agents Chemother.
Title : Influence on mitochondria and cytotoxicity of different antibiotics administered in high concentrations on primary human osteoblasts and cell lines.
Year : 2007
Volume : 51
Issue : 1
First Page : 54
Last Page : 63
Authors : Duewelhenke N, Krut O, Eysel P.
Abstract : Osteomyelitis, osteitis, spondylodiscitis, septic arthritis, and prosthetic joint infections still represent the worst complications of orthopedic surgery and traumatology. Successful treatment requires, besides surgical débridement, long-term systemic and high-concentration local antibiotic therapy, with possible local antibiotic concentrations of 100 microg/ml and more. In this study, we investigated the effect of 20 different antibiotics on primary human osteoblasts (PHO), the osteosarcoma cell line MG63, and the epithelial cell line HeLa. High concentrations of fluoroquinolones, macrolides, clindamycin, chloramphenicol, rifampin, tetracycline, and linezolid during 48 h of incubation inhibited proliferation and metabolic activity, whereas aminoglycosides and inhibitors of bacterial cell wall synthesis did not. Twenty percent inhibitory concentrations for proliferation of PHO were determined as 20 to 40 microg/ml for macrolides, clindamycin, and rifampin, 60 to 80 microg/ml for chloramphenicol, tetracylin, and fluoroquinolones, and 240 microg/ml for linezolid. The proliferation of the cell lines was always less inhibited. We established the measurement of extracellular lactate concentration as an indicator of glycolysis using inhibitors of the respiratory chain (antimycin A, rotenone, and sodium azide) and glycolysis (iodoacetic acid) as reference compounds, whereas inhibition of the respiratory chain increased and inhibition of glycolysis decreased lactate production. The measurement of extracellular lactate concentration revealed that fluoroquinolones, macrolides, clindamycin, rifampin, tetracycline, and especially chloramphenicol and linezolid impaired mitochondrial energetics in high concentrations. This explains partly the observed inhibition of metabolic activity and proliferation in our experiments. Because of differences in the energy metabolism, PHO provided a more sensitive model for orthopedic antibiotic usage than stable cell lines.
|
Antiproliferative effect against MG63 cells assessed as BrdU incorporation into DNA after 48 hrs after 48 hrs
|
Homo sapiens
|
190.0
ug.mL-1
|
|
Journal : Antimicrob. Agents Chemother.
Title : Influence on mitochondria and cytotoxicity of different antibiotics administered in high concentrations on primary human osteoblasts and cell lines.
Year : 2007
Volume : 51
Issue : 1
First Page : 54
Last Page : 63
Authors : Duewelhenke N, Krut O, Eysel P.
Abstract : Osteomyelitis, osteitis, spondylodiscitis, septic arthritis, and prosthetic joint infections still represent the worst complications of orthopedic surgery and traumatology. Successful treatment requires, besides surgical débridement, long-term systemic and high-concentration local antibiotic therapy, with possible local antibiotic concentrations of 100 microg/ml and more. In this study, we investigated the effect of 20 different antibiotics on primary human osteoblasts (PHO), the osteosarcoma cell line MG63, and the epithelial cell line HeLa. High concentrations of fluoroquinolones, macrolides, clindamycin, chloramphenicol, rifampin, tetracycline, and linezolid during 48 h of incubation inhibited proliferation and metabolic activity, whereas aminoglycosides and inhibitors of bacterial cell wall synthesis did not. Twenty percent inhibitory concentrations for proliferation of PHO were determined as 20 to 40 microg/ml for macrolides, clindamycin, and rifampin, 60 to 80 microg/ml for chloramphenicol, tetracylin, and fluoroquinolones, and 240 microg/ml for linezolid. The proliferation of the cell lines was always less inhibited. We established the measurement of extracellular lactate concentration as an indicator of glycolysis using inhibitors of the respiratory chain (antimycin A, rotenone, and sodium azide) and glycolysis (iodoacetic acid) as reference compounds, whereas inhibition of the respiratory chain increased and inhibition of glycolysis decreased lactate production. The measurement of extracellular lactate concentration revealed that fluoroquinolones, macrolides, clindamycin, rifampin, tetracycline, and especially chloramphenicol and linezolid impaired mitochondrial energetics in high concentrations. This explains partly the observed inhibition of metabolic activity and proliferation in our experiments. Because of differences in the energy metabolism, PHO provided a more sensitive model for orthopedic antibiotic usage than stable cell lines.
|
Inhibition of metabolic activity in MG63 cells assessed as MTT reduction after 48 hrs
|
Homo sapiens
|
180.0
ug.mL-1
|
|
Journal : Antimicrob. Agents Chemother.
Title : Influence on mitochondria and cytotoxicity of different antibiotics administered in high concentrations on primary human osteoblasts and cell lines.
Year : 2007
Volume : 51
Issue : 1
First Page : 54
Last Page : 63
Authors : Duewelhenke N, Krut O, Eysel P.
Abstract : Osteomyelitis, osteitis, spondylodiscitis, septic arthritis, and prosthetic joint infections still represent the worst complications of orthopedic surgery and traumatology. Successful treatment requires, besides surgical débridement, long-term systemic and high-concentration local antibiotic therapy, with possible local antibiotic concentrations of 100 microg/ml and more. In this study, we investigated the effect of 20 different antibiotics on primary human osteoblasts (PHO), the osteosarcoma cell line MG63, and the epithelial cell line HeLa. High concentrations of fluoroquinolones, macrolides, clindamycin, chloramphenicol, rifampin, tetracycline, and linezolid during 48 h of incubation inhibited proliferation and metabolic activity, whereas aminoglycosides and inhibitors of bacterial cell wall synthesis did not. Twenty percent inhibitory concentrations for proliferation of PHO were determined as 20 to 40 microg/ml for macrolides, clindamycin, and rifampin, 60 to 80 microg/ml for chloramphenicol, tetracylin, and fluoroquinolones, and 240 microg/ml for linezolid. The proliferation of the cell lines was always less inhibited. We established the measurement of extracellular lactate concentration as an indicator of glycolysis using inhibitors of the respiratory chain (antimycin A, rotenone, and sodium azide) and glycolysis (iodoacetic acid) as reference compounds, whereas inhibition of the respiratory chain increased and inhibition of glycolysis decreased lactate production. The measurement of extracellular lactate concentration revealed that fluoroquinolones, macrolides, clindamycin, rifampin, tetracycline, and especially chloramphenicol and linezolid impaired mitochondrial energetics in high concentrations. This explains partly the observed inhibition of metabolic activity and proliferation in our experiments. Because of differences in the energy metabolism, PHO provided a more sensitive model for orthopedic antibiotic usage than stable cell lines.
|
Antiproliferative effect against HeLa cells after 48 hrs
|
Homo sapiens
|
240.0
ug.mL-1
|
|
Journal : Antimicrob. Agents Chemother.
Title : Influence on mitochondria and cytotoxicity of different antibiotics administered in high concentrations on primary human osteoblasts and cell lines.
Year : 2007
Volume : 51
Issue : 1
First Page : 54
Last Page : 63
Authors : Duewelhenke N, Krut O, Eysel P.
Abstract : Osteomyelitis, osteitis, spondylodiscitis, septic arthritis, and prosthetic joint infections still represent the worst complications of orthopedic surgery and traumatology. Successful treatment requires, besides surgical débridement, long-term systemic and high-concentration local antibiotic therapy, with possible local antibiotic concentrations of 100 microg/ml and more. In this study, we investigated the effect of 20 different antibiotics on primary human osteoblasts (PHO), the osteosarcoma cell line MG63, and the epithelial cell line HeLa. High concentrations of fluoroquinolones, macrolides, clindamycin, chloramphenicol, rifampin, tetracycline, and linezolid during 48 h of incubation inhibited proliferation and metabolic activity, whereas aminoglycosides and inhibitors of bacterial cell wall synthesis did not. Twenty percent inhibitory concentrations for proliferation of PHO were determined as 20 to 40 microg/ml for macrolides, clindamycin, and rifampin, 60 to 80 microg/ml for chloramphenicol, tetracylin, and fluoroquinolones, and 240 microg/ml for linezolid. The proliferation of the cell lines was always less inhibited. We established the measurement of extracellular lactate concentration as an indicator of glycolysis using inhibitors of the respiratory chain (antimycin A, rotenone, and sodium azide) and glycolysis (iodoacetic acid) as reference compounds, whereas inhibition of the respiratory chain increased and inhibition of glycolysis decreased lactate production. The measurement of extracellular lactate concentration revealed that fluoroquinolones, macrolides, clindamycin, rifampin, tetracycline, and especially chloramphenicol and linezolid impaired mitochondrial energetics in high concentrations. This explains partly the observed inhibition of metabolic activity and proliferation in our experiments. Because of differences in the energy metabolism, PHO provided a more sensitive model for orthopedic antibiotic usage than stable cell lines.
|
Inhibition of metabolic activity in HeLa cells assessed as MTT reduction after 48 hrs
|
Homo sapiens
|
160.0
ug.mL-1
|
|
Journal : Antimicrob. Agents Chemother.
Title : Influence on mitochondria and cytotoxicity of different antibiotics administered in high concentrations on primary human osteoblasts and cell lines.
Year : 2007
Volume : 51
Issue : 1
First Page : 54
Last Page : 63
Authors : Duewelhenke N, Krut O, Eysel P.
Abstract : Osteomyelitis, osteitis, spondylodiscitis, septic arthritis, and prosthetic joint infections still represent the worst complications of orthopedic surgery and traumatology. Successful treatment requires, besides surgical débridement, long-term systemic and high-concentration local antibiotic therapy, with possible local antibiotic concentrations of 100 microg/ml and more. In this study, we investigated the effect of 20 different antibiotics on primary human osteoblasts (PHO), the osteosarcoma cell line MG63, and the epithelial cell line HeLa. High concentrations of fluoroquinolones, macrolides, clindamycin, chloramphenicol, rifampin, tetracycline, and linezolid during 48 h of incubation inhibited proliferation and metabolic activity, whereas aminoglycosides and inhibitors of bacterial cell wall synthesis did not. Twenty percent inhibitory concentrations for proliferation of PHO were determined as 20 to 40 microg/ml for macrolides, clindamycin, and rifampin, 60 to 80 microg/ml for chloramphenicol, tetracylin, and fluoroquinolones, and 240 microg/ml for linezolid. The proliferation of the cell lines was always less inhibited. We established the measurement of extracellular lactate concentration as an indicator of glycolysis using inhibitors of the respiratory chain (antimycin A, rotenone, and sodium azide) and glycolysis (iodoacetic acid) as reference compounds, whereas inhibition of the respiratory chain increased and inhibition of glycolysis decreased lactate production. The measurement of extracellular lactate concentration revealed that fluoroquinolones, macrolides, clindamycin, rifampin, tetracycline, and especially chloramphenicol and linezolid impaired mitochondrial energetics in high concentrations. This explains partly the observed inhibition of metabolic activity and proliferation in our experiments. Because of differences in the energy metabolism, PHO provided a more sensitive model for orthopedic antibiotic usage than stable cell lines.
|
Inhibition of Plasmodium falciparum in HRP2 ELISA
|
Plasmodium falciparum
|
2.57
ug.mL-1
|
|
Journal : Antimicrob. Agents Chemother.
Title : In vitro antimalarial activity of azithromycin, artesunate, and quinine in combination and correlation with clinical outcome.
Year : 2007
Volume : 51
Issue : 2
First Page : 651
Last Page : 656
Authors : Noedl H, Krudsood S, Leowattana W, Tangpukdee N, Thanachartwet W, Looareesuwan S, Miller RS, Fukuda M, Jongsakul K, Yingyuen K, Sriwichai S, Ohrt C, Knirsch C.
Abstract : Azithromycin when used in combination with faster-acting antimalarials has proven efficacious in treating Plasmodium falciparum malaria in phase 2 clinical trials. The aim of this study was to establish optimal combination ratios for azithromycin in combination with either dihydroartemisinin or quinine, to determine the clinical correlates of in vitro drug sensitivity for these compounds, and to assess the cross-sensitivity patterns. Seventy-three fresh P. falciparum isolates originating from patients from the western border regions of Thailand were successfully tested for their drug susceptibility in a histidine-rich protein 2 (HRP2) assay. With overall mean fractional inhibitory concentrations of 0.84 (95% confidence interval [CI]=0.77 to 1.08) and 0.78 (95% CI=0.72 to 0.98), the interactions between azithromycin and dihydroartemisinin, as well as quinine, were classified as additive, with a tendency toward synergism. The strongest tendency toward synergy was seen with a combination ratio of 1:547 for the combination with dihydroartemisinin and 1:44 with quinine. The geometric mean 50% inhibitory concentration (IC50) of azithromycin was 2,570.3 (95% CI=2,175.58 to 3,036.58) ng/ml. The IC50s for mefloquine, quinine, and chloroquine were 11.42, 64.4, and 54.4 ng/ml, respectively, suggesting a relatively high level of background resistance in this patient population. Distinct correlations (R=0.53; P=0.001) between quinine in vitro results and parasite clearance may indicate a compromised sensitivity to this drug. The correlation with dihydroartemisinin data was weaker (R=0.34; P=0.038), and no such correlation was observed for azithromycin. Our in vitro data confirm that azithromycin in combination with artemisinin derivatives or quinine exerts additive to synergistic interactions, shows no cross-sensitivity with traditional antimalarials, and has substantial antimalarial activity on its own.
|
Inhibition of Plasmodium falciparum AZ10011003 isolate in HRP2 ELISA
|
Plasmodium falciparum
|
2.444
ug.mL-1
|
|
Journal : Antimicrob. Agents Chemother.
Title : In vitro antimalarial activity of azithromycin, artesunate, and quinine in combination and correlation with clinical outcome.
Year : 2007
Volume : 51
Issue : 2
First Page : 651
Last Page : 656
Authors : Noedl H, Krudsood S, Leowattana W, Tangpukdee N, Thanachartwet W, Looareesuwan S, Miller RS, Fukuda M, Jongsakul K, Yingyuen K, Sriwichai S, Ohrt C, Knirsch C.
Abstract : Azithromycin when used in combination with faster-acting antimalarials has proven efficacious in treating Plasmodium falciparum malaria in phase 2 clinical trials. The aim of this study was to establish optimal combination ratios for azithromycin in combination with either dihydroartemisinin or quinine, to determine the clinical correlates of in vitro drug sensitivity for these compounds, and to assess the cross-sensitivity patterns. Seventy-three fresh P. falciparum isolates originating from patients from the western border regions of Thailand were successfully tested for their drug susceptibility in a histidine-rich protein 2 (HRP2) assay. With overall mean fractional inhibitory concentrations of 0.84 (95% confidence interval [CI]=0.77 to 1.08) and 0.78 (95% CI=0.72 to 0.98), the interactions between azithromycin and dihydroartemisinin, as well as quinine, were classified as additive, with a tendency toward synergism. The strongest tendency toward synergy was seen with a combination ratio of 1:547 for the combination with dihydroartemisinin and 1:44 with quinine. The geometric mean 50% inhibitory concentration (IC50) of azithromycin was 2,570.3 (95% CI=2,175.58 to 3,036.58) ng/ml. The IC50s for mefloquine, quinine, and chloroquine were 11.42, 64.4, and 54.4 ng/ml, respectively, suggesting a relatively high level of background resistance in this patient population. Distinct correlations (R=0.53; P=0.001) between quinine in vitro results and parasite clearance may indicate a compromised sensitivity to this drug. The correlation with dihydroartemisinin data was weaker (R=0.34; P=0.038), and no such correlation was observed for azithromycin. Our in vitro data confirm that azithromycin in combination with artemisinin derivatives or quinine exerts additive to synergistic interactions, shows no cross-sensitivity with traditional antimalarials, and has substantial antimalarial activity on its own.
|
Inhibition of Plasmodium falciparum AZ10011008 isolate in HRP2 ELISA
|
Plasmodium falciparum
|
5.342
ug.mL-1
|
|
Journal : Antimicrob. Agents Chemother.
Title : In vitro antimalarial activity of azithromycin, artesunate, and quinine in combination and correlation with clinical outcome.
Year : 2007
Volume : 51
Issue : 2
First Page : 651
Last Page : 656
Authors : Noedl H, Krudsood S, Leowattana W, Tangpukdee N, Thanachartwet W, Looareesuwan S, Miller RS, Fukuda M, Jongsakul K, Yingyuen K, Sriwichai S, Ohrt C, Knirsch C.
Abstract : Azithromycin when used in combination with faster-acting antimalarials has proven efficacious in treating Plasmodium falciparum malaria in phase 2 clinical trials. The aim of this study was to establish optimal combination ratios for azithromycin in combination with either dihydroartemisinin or quinine, to determine the clinical correlates of in vitro drug sensitivity for these compounds, and to assess the cross-sensitivity patterns. Seventy-three fresh P. falciparum isolates originating from patients from the western border regions of Thailand were successfully tested for their drug susceptibility in a histidine-rich protein 2 (HRP2) assay. With overall mean fractional inhibitory concentrations of 0.84 (95% confidence interval [CI]=0.77 to 1.08) and 0.78 (95% CI=0.72 to 0.98), the interactions between azithromycin and dihydroartemisinin, as well as quinine, were classified as additive, with a tendency toward synergism. The strongest tendency toward synergy was seen with a combination ratio of 1:547 for the combination with dihydroartemisinin and 1:44 with quinine. The geometric mean 50% inhibitory concentration (IC50) of azithromycin was 2,570.3 (95% CI=2,175.58 to 3,036.58) ng/ml. The IC50s for mefloquine, quinine, and chloroquine were 11.42, 64.4, and 54.4 ng/ml, respectively, suggesting a relatively high level of background resistance in this patient population. Distinct correlations (R=0.53; P=0.001) between quinine in vitro results and parasite clearance may indicate a compromised sensitivity to this drug. The correlation with dihydroartemisinin data was weaker (R=0.34; P=0.038), and no such correlation was observed for azithromycin. Our in vitro data confirm that azithromycin in combination with artemisinin derivatives or quinine exerts additive to synergistic interactions, shows no cross-sensitivity with traditional antimalarials, and has substantial antimalarial activity on its own.
|
Inhibition of Plasmodium falciparum AZ10011017 isolate in HRP2 ELISA
|
Plasmodium falciparum
|
1.976
ug.mL-1
|
|
Journal : Antimicrob. Agents Chemother.
Title : In vitro antimalarial activity of azithromycin, artesunate, and quinine in combination and correlation with clinical outcome.
Year : 2007
Volume : 51
Issue : 2
First Page : 651
Last Page : 656
Authors : Noedl H, Krudsood S, Leowattana W, Tangpukdee N, Thanachartwet W, Looareesuwan S, Miller RS, Fukuda M, Jongsakul K, Yingyuen K, Sriwichai S, Ohrt C, Knirsch C.
Abstract : Azithromycin when used in combination with faster-acting antimalarials has proven efficacious in treating Plasmodium falciparum malaria in phase 2 clinical trials. The aim of this study was to establish optimal combination ratios for azithromycin in combination with either dihydroartemisinin or quinine, to determine the clinical correlates of in vitro drug sensitivity for these compounds, and to assess the cross-sensitivity patterns. Seventy-three fresh P. falciparum isolates originating from patients from the western border regions of Thailand were successfully tested for their drug susceptibility in a histidine-rich protein 2 (HRP2) assay. With overall mean fractional inhibitory concentrations of 0.84 (95% confidence interval [CI]=0.77 to 1.08) and 0.78 (95% CI=0.72 to 0.98), the interactions between azithromycin and dihydroartemisinin, as well as quinine, were classified as additive, with a tendency toward synergism. The strongest tendency toward synergy was seen with a combination ratio of 1:547 for the combination with dihydroartemisinin and 1:44 with quinine. The geometric mean 50% inhibitory concentration (IC50) of azithromycin was 2,570.3 (95% CI=2,175.58 to 3,036.58) ng/ml. The IC50s for mefloquine, quinine, and chloroquine were 11.42, 64.4, and 54.4 ng/ml, respectively, suggesting a relatively high level of background resistance in this patient population. Distinct correlations (R=0.53; P=0.001) between quinine in vitro results and parasite clearance may indicate a compromised sensitivity to this drug. The correlation with dihydroartemisinin data was weaker (R=0.34; P=0.038), and no such correlation was observed for azithromycin. Our in vitro data confirm that azithromycin in combination with artemisinin derivatives or quinine exerts additive to synergistic interactions, shows no cross-sensitivity with traditional antimalarials, and has substantial antimalarial activity on its own.
|
Inhibition of Plasmodium falciparum AZ10011022 isolate in HRP2 ELISA
|
Plasmodium falciparum
|
2.19
ug.mL-1
|
|
Journal : Antimicrob. Agents Chemother.
Title : In vitro antimalarial activity of azithromycin, artesunate, and quinine in combination and correlation with clinical outcome.
Year : 2007
Volume : 51
Issue : 2
First Page : 651
Last Page : 656
Authors : Noedl H, Krudsood S, Leowattana W, Tangpukdee N, Thanachartwet W, Looareesuwan S, Miller RS, Fukuda M, Jongsakul K, Yingyuen K, Sriwichai S, Ohrt C, Knirsch C.
Abstract : Azithromycin when used in combination with faster-acting antimalarials has proven efficacious in treating Plasmodium falciparum malaria in phase 2 clinical trials. The aim of this study was to establish optimal combination ratios for azithromycin in combination with either dihydroartemisinin or quinine, to determine the clinical correlates of in vitro drug sensitivity for these compounds, and to assess the cross-sensitivity patterns. Seventy-three fresh P. falciparum isolates originating from patients from the western border regions of Thailand were successfully tested for their drug susceptibility in a histidine-rich protein 2 (HRP2) assay. With overall mean fractional inhibitory concentrations of 0.84 (95% confidence interval [CI]=0.77 to 1.08) and 0.78 (95% CI=0.72 to 0.98), the interactions between azithromycin and dihydroartemisinin, as well as quinine, were classified as additive, with a tendency toward synergism. The strongest tendency toward synergy was seen with a combination ratio of 1:547 for the combination with dihydroartemisinin and 1:44 with quinine. The geometric mean 50% inhibitory concentration (IC50) of azithromycin was 2,570.3 (95% CI=2,175.58 to 3,036.58) ng/ml. The IC50s for mefloquine, quinine, and chloroquine were 11.42, 64.4, and 54.4 ng/ml, respectively, suggesting a relatively high level of background resistance in this patient population. Distinct correlations (R=0.53; P=0.001) between quinine in vitro results and parasite clearance may indicate a compromised sensitivity to this drug. The correlation with dihydroartemisinin data was weaker (R=0.34; P=0.038), and no such correlation was observed for azithromycin. Our in vitro data confirm that azithromycin in combination with artemisinin derivatives or quinine exerts additive to synergistic interactions, shows no cross-sensitivity with traditional antimalarials, and has substantial antimalarial activity on its own.
|
In vitro antimalarial activity against Plasmodium falciparum D6 after 72 hrs in SYBR green fluorescence assay
|
Plasmodium falciparum
|
10.13
ug.mL-1
|
|
Journal : Antimicrob. Agents Chemother.
Title : Assessment and continued validation of the malaria SYBR green I-based fluorescence assay for use in malaria drug screening.
Year : 2007
Volume : 51
Issue : 6
First Page : 1926
Last Page : 1933
Authors : Johnson JD, Dennull RA, Gerena L, Lopez-Sanchez M, Roncal NE, Waters NC.
Abstract : Several new fluorescence malaria in vitro drug susceptibility microtiter plate assays that detect the presence of malarial DNA in infected erythrocytes have recently been reported, in contrast to traditional isotopic screens that involve radioactive substrate incorporation to measure in vitro malaria growth inhibition. We have assessed and further characterized the malaria SYBR Green I-based fluorescence (MSF) assay for its ability to monitor drug resistance. In order to use the MSF assay as a drug screen, all assay conditions must be thoroughly examined. In this study we expanded upon the capabilities of this assay by including antibiotics and antifolates in the drug panel and testing folic acid-free growth conditions. To do this, we evaluated a more expansive panel of antimalarials in combination with various drug assay culture conditions commonly used in drug sensitivity screening for their activity against Plasmodium falciparum strains D6 and W2. The detection and quantitation limits of the MSF assay were 0.04 to 0.08% and approximately 0.5% parasitemia, respectively. The MSF assay quality was significantly robust, displaying a Z' range of 0.73 to 0.95. The 50% inhibitory concentrations for each drug and culture condition combination were determined by using the MSF assay. Compared to the standard [(3)H]hypoxanthine assay, the MSF assay displayed the expected parasite drug resistance patterns with a high degree of global and phenotypic correlation (r(2) >/= 0.9238), regardless of which culture condition combination was used. In conclusion, the MSF assay allows for reliable one-plate high-throughput, automated malaria in vitro susceptibility testing without the expense, time consumption, and hazard of other screening assays.
|
In vitro antimalarial activity against Plasmodium falciparum W2 after 72 hrs in SYBR green fluorescence assay
|
Plasmodium falciparum
|
1.623
ug.mL-1
|
|
Journal : Antimicrob. Agents Chemother.
Title : Assessment and continued validation of the malaria SYBR green I-based fluorescence assay for use in malaria drug screening.
Year : 2007
Volume : 51
Issue : 6
First Page : 1926
Last Page : 1933
Authors : Johnson JD, Dennull RA, Gerena L, Lopez-Sanchez M, Roncal NE, Waters NC.
Abstract : Several new fluorescence malaria in vitro drug susceptibility microtiter plate assays that detect the presence of malarial DNA in infected erythrocytes have recently been reported, in contrast to traditional isotopic screens that involve radioactive substrate incorporation to measure in vitro malaria growth inhibition. We have assessed and further characterized the malaria SYBR Green I-based fluorescence (MSF) assay for its ability to monitor drug resistance. In order to use the MSF assay as a drug screen, all assay conditions must be thoroughly examined. In this study we expanded upon the capabilities of this assay by including antibiotics and antifolates in the drug panel and testing folic acid-free growth conditions. To do this, we evaluated a more expansive panel of antimalarials in combination with various drug assay culture conditions commonly used in drug sensitivity screening for their activity against Plasmodium falciparum strains D6 and W2. The detection and quantitation limits of the MSF assay were 0.04 to 0.08% and approximately 0.5% parasitemia, respectively. The MSF assay quality was significantly robust, displaying a Z' range of 0.73 to 0.95. The 50% inhibitory concentrations for each drug and culture condition combination were determined by using the MSF assay. Compared to the standard [(3)H]hypoxanthine assay, the MSF assay displayed the expected parasite drug resistance patterns with a high degree of global and phenotypic correlation (r(2) >/= 0.9238), regardless of which culture condition combination was used. In conclusion, the MSF assay allows for reliable one-plate high-throughput, automated malaria in vitro susceptibility testing without the expense, time consumption, and hazard of other screening assays.
|
In vitro antimalarial activity against Plasmodium falciparum D6 after 72 hrs by SYBR green fluorescence assay
|
Plasmodium falciparum
|
15.28
ug.mL-1
|
|
Journal : Antimicrob. Agents Chemother.
Title : Assessment and continued validation of the malaria SYBR green I-based fluorescence assay for use in malaria drug screening.
Year : 2007
Volume : 51
Issue : 6
First Page : 1926
Last Page : 1933
Authors : Johnson JD, Dennull RA, Gerena L, Lopez-Sanchez M, Roncal NE, Waters NC.
Abstract : Several new fluorescence malaria in vitro drug susceptibility microtiter plate assays that detect the presence of malarial DNA in infected erythrocytes have recently been reported, in contrast to traditional isotopic screens that involve radioactive substrate incorporation to measure in vitro malaria growth inhibition. We have assessed and further characterized the malaria SYBR Green I-based fluorescence (MSF) assay for its ability to monitor drug resistance. In order to use the MSF assay as a drug screen, all assay conditions must be thoroughly examined. In this study we expanded upon the capabilities of this assay by including antibiotics and antifolates in the drug panel and testing folic acid-free growth conditions. To do this, we evaluated a more expansive panel of antimalarials in combination with various drug assay culture conditions commonly used in drug sensitivity screening for their activity against Plasmodium falciparum strains D6 and W2. The detection and quantitation limits of the MSF assay were 0.04 to 0.08% and approximately 0.5% parasitemia, respectively. The MSF assay quality was significantly robust, displaying a Z' range of 0.73 to 0.95. The 50% inhibitory concentrations for each drug and culture condition combination were determined by using the MSF assay. Compared to the standard [(3)H]hypoxanthine assay, the MSF assay displayed the expected parasite drug resistance patterns with a high degree of global and phenotypic correlation (r(2) >/= 0.9238), regardless of which culture condition combination was used. In conclusion, the MSF assay allows for reliable one-plate high-throughput, automated malaria in vitro susceptibility testing without the expense, time consumption, and hazard of other screening assays.
|
In vitro antimalarial activity against Plasmodium falciparum W2 after 72 hrs by SYBR green fluorescence assay
|
Plasmodium falciparum
|
2.734
ug.mL-1
|
|
Journal : Antimicrob. Agents Chemother.
Title : Assessment and continued validation of the malaria SYBR green I-based fluorescence assay for use in malaria drug screening.
Year : 2007
Volume : 51
Issue : 6
First Page : 1926
Last Page : 1933
Authors : Johnson JD, Dennull RA, Gerena L, Lopez-Sanchez M, Roncal NE, Waters NC.
Abstract : Several new fluorescence malaria in vitro drug susceptibility microtiter plate assays that detect the presence of malarial DNA in infected erythrocytes have recently been reported, in contrast to traditional isotopic screens that involve radioactive substrate incorporation to measure in vitro malaria growth inhibition. We have assessed and further characterized the malaria SYBR Green I-based fluorescence (MSF) assay for its ability to monitor drug resistance. In order to use the MSF assay as a drug screen, all assay conditions must be thoroughly examined. In this study we expanded upon the capabilities of this assay by including antibiotics and antifolates in the drug panel and testing folic acid-free growth conditions. To do this, we evaluated a more expansive panel of antimalarials in combination with various drug assay culture conditions commonly used in drug sensitivity screening for their activity against Plasmodium falciparum strains D6 and W2. The detection and quantitation limits of the MSF assay were 0.04 to 0.08% and approximately 0.5% parasitemia, respectively. The MSF assay quality was significantly robust, displaying a Z' range of 0.73 to 0.95. The 50% inhibitory concentrations for each drug and culture condition combination were determined by using the MSF assay. Compared to the standard [(3)H]hypoxanthine assay, the MSF assay displayed the expected parasite drug resistance patterns with a high degree of global and phenotypic correlation (r(2) >/= 0.9238), regardless of which culture condition combination was used. In conclusion, the MSF assay allows for reliable one-plate high-throughput, automated malaria in vitro susceptibility testing without the expense, time consumption, and hazard of other screening assays.
|
In vitro antimalarial activity against Plasmodium falciparum D6 after 72 hrs in SYBR green fluorescence assay
|
Plasmodium falciparum
|
10.07
ug.mL-1
|
|
Journal : Antimicrob. Agents Chemother.
Title : Assessment and continued validation of the malaria SYBR green I-based fluorescence assay for use in malaria drug screening.
Year : 2007
Volume : 51
Issue : 6
First Page : 1926
Last Page : 1933
Authors : Johnson JD, Dennull RA, Gerena L, Lopez-Sanchez M, Roncal NE, Waters NC.
Abstract : Several new fluorescence malaria in vitro drug susceptibility microtiter plate assays that detect the presence of malarial DNA in infected erythrocytes have recently been reported, in contrast to traditional isotopic screens that involve radioactive substrate incorporation to measure in vitro malaria growth inhibition. We have assessed and further characterized the malaria SYBR Green I-based fluorescence (MSF) assay for its ability to monitor drug resistance. In order to use the MSF assay as a drug screen, all assay conditions must be thoroughly examined. In this study we expanded upon the capabilities of this assay by including antibiotics and antifolates in the drug panel and testing folic acid-free growth conditions. To do this, we evaluated a more expansive panel of antimalarials in combination with various drug assay culture conditions commonly used in drug sensitivity screening for their activity against Plasmodium falciparum strains D6 and W2. The detection and quantitation limits of the MSF assay were 0.04 to 0.08% and approximately 0.5% parasitemia, respectively. The MSF assay quality was significantly robust, displaying a Z' range of 0.73 to 0.95. The 50% inhibitory concentrations for each drug and culture condition combination were determined by using the MSF assay. Compared to the standard [(3)H]hypoxanthine assay, the MSF assay displayed the expected parasite drug resistance patterns with a high degree of global and phenotypic correlation (r(2) >/= 0.9238), regardless of which culture condition combination was used. In conclusion, the MSF assay allows for reliable one-plate high-throughput, automated malaria in vitro susceptibility testing without the expense, time consumption, and hazard of other screening assays.
|
In vitro antimalarial activity against Plasmodium falciparum W2 after 72 hrs in SYBR green fluorescence assay
|
Plasmodium falciparum
|
1.848
ug.mL-1
|
|
Journal : Antimicrob. Agents Chemother.
Title : Assessment and continued validation of the malaria SYBR green I-based fluorescence assay for use in malaria drug screening.
Year : 2007
Volume : 51
Issue : 6
First Page : 1926
Last Page : 1933
Authors : Johnson JD, Dennull RA, Gerena L, Lopez-Sanchez M, Roncal NE, Waters NC.
Abstract : Several new fluorescence malaria in vitro drug susceptibility microtiter plate assays that detect the presence of malarial DNA in infected erythrocytes have recently been reported, in contrast to traditional isotopic screens that involve radioactive substrate incorporation to measure in vitro malaria growth inhibition. We have assessed and further characterized the malaria SYBR Green I-based fluorescence (MSF) assay for its ability to monitor drug resistance. In order to use the MSF assay as a drug screen, all assay conditions must be thoroughly examined. In this study we expanded upon the capabilities of this assay by including antibiotics and antifolates in the drug panel and testing folic acid-free growth conditions. To do this, we evaluated a more expansive panel of antimalarials in combination with various drug assay culture conditions commonly used in drug sensitivity screening for their activity against Plasmodium falciparum strains D6 and W2. The detection and quantitation limits of the MSF assay were 0.04 to 0.08% and approximately 0.5% parasitemia, respectively. The MSF assay quality was significantly robust, displaying a Z' range of 0.73 to 0.95. The 50% inhibitory concentrations for each drug and culture condition combination were determined by using the MSF assay. Compared to the standard [(3)H]hypoxanthine assay, the MSF assay displayed the expected parasite drug resistance patterns with a high degree of global and phenotypic correlation (r(2) >/= 0.9238), regardless of which culture condition combination was used. In conclusion, the MSF assay allows for reliable one-plate high-throughput, automated malaria in vitro susceptibility testing without the expense, time consumption, and hazard of other screening assays.
|
In vitro antimalarial activity against Plasmodium falciparum D6 after 72 hrs in SYBR green fluorescence assay
|
Plasmodium falciparum
|
14.36
ug.mL-1
|
|
Journal : Antimicrob. Agents Chemother.
Title : Assessment and continued validation of the malaria SYBR green I-based fluorescence assay for use in malaria drug screening.
Year : 2007
Volume : 51
Issue : 6
First Page : 1926
Last Page : 1933
Authors : Johnson JD, Dennull RA, Gerena L, Lopez-Sanchez M, Roncal NE, Waters NC.
Abstract : Several new fluorescence malaria in vitro drug susceptibility microtiter plate assays that detect the presence of malarial DNA in infected erythrocytes have recently been reported, in contrast to traditional isotopic screens that involve radioactive substrate incorporation to measure in vitro malaria growth inhibition. We have assessed and further characterized the malaria SYBR Green I-based fluorescence (MSF) assay for its ability to monitor drug resistance. In order to use the MSF assay as a drug screen, all assay conditions must be thoroughly examined. In this study we expanded upon the capabilities of this assay by including antibiotics and antifolates in the drug panel and testing folic acid-free growth conditions. To do this, we evaluated a more expansive panel of antimalarials in combination with various drug assay culture conditions commonly used in drug sensitivity screening for their activity against Plasmodium falciparum strains D6 and W2. The detection and quantitation limits of the MSF assay were 0.04 to 0.08% and approximately 0.5% parasitemia, respectively. The MSF assay quality was significantly robust, displaying a Z' range of 0.73 to 0.95. The 50% inhibitory concentrations for each drug and culture condition combination were determined by using the MSF assay. Compared to the standard [(3)H]hypoxanthine assay, the MSF assay displayed the expected parasite drug resistance patterns with a high degree of global and phenotypic correlation (r(2) >/= 0.9238), regardless of which culture condition combination was used. In conclusion, the MSF assay allows for reliable one-plate high-throughput, automated malaria in vitro susceptibility testing without the expense, time consumption, and hazard of other screening assays.
|
In vitro antimalarial activity against Plasmodium falciparum W2 after 72 hrs in SYBR green fluorescence assay
|
Plasmodium falciparum
|
4.489
ug.mL-1
|
|
Journal : Antimicrob. Agents Chemother.
Title : Assessment and continued validation of the malaria SYBR green I-based fluorescence assay for use in malaria drug screening.
Year : 2007
Volume : 51
Issue : 6
First Page : 1926
Last Page : 1933
Authors : Johnson JD, Dennull RA, Gerena L, Lopez-Sanchez M, Roncal NE, Waters NC.
Abstract : Several new fluorescence malaria in vitro drug susceptibility microtiter plate assays that detect the presence of malarial DNA in infected erythrocytes have recently been reported, in contrast to traditional isotopic screens that involve radioactive substrate incorporation to measure in vitro malaria growth inhibition. We have assessed and further characterized the malaria SYBR Green I-based fluorescence (MSF) assay for its ability to monitor drug resistance. In order to use the MSF assay as a drug screen, all assay conditions must be thoroughly examined. In this study we expanded upon the capabilities of this assay by including antibiotics and antifolates in the drug panel and testing folic acid-free growth conditions. To do this, we evaluated a more expansive panel of antimalarials in combination with various drug assay culture conditions commonly used in drug sensitivity screening for their activity against Plasmodium falciparum strains D6 and W2. The detection and quantitation limits of the MSF assay were 0.04 to 0.08% and approximately 0.5% parasitemia, respectively. The MSF assay quality was significantly robust, displaying a Z' range of 0.73 to 0.95. The 50% inhibitory concentrations for each drug and culture condition combination were determined by using the MSF assay. Compared to the standard [(3)H]hypoxanthine assay, the MSF assay displayed the expected parasite drug resistance patterns with a high degree of global and phenotypic correlation (r(2) >/= 0.9238), regardless of which culture condition combination was used. In conclusion, the MSF assay allows for reliable one-plate high-throughput, automated malaria in vitro susceptibility testing without the expense, time consumption, and hazard of other screening assays.
|
Antimalarial activity against Plasmodium falciparum D6 as reduced [3H]hypoxanthine uptake after 72 hrs
|
Plasmodium falciparum
|
3.747
ug.mL-1
|
|
Journal : Antimicrob. Agents Chemother.
Title : Assessment and continued validation of the malaria SYBR green I-based fluorescence assay for use in malaria drug screening.
Year : 2007
Volume : 51
Issue : 6
First Page : 1926
Last Page : 1933
Authors : Johnson JD, Dennull RA, Gerena L, Lopez-Sanchez M, Roncal NE, Waters NC.
Abstract : Several new fluorescence malaria in vitro drug susceptibility microtiter plate assays that detect the presence of malarial DNA in infected erythrocytes have recently been reported, in contrast to traditional isotopic screens that involve radioactive substrate incorporation to measure in vitro malaria growth inhibition. We have assessed and further characterized the malaria SYBR Green I-based fluorescence (MSF) assay for its ability to monitor drug resistance. In order to use the MSF assay as a drug screen, all assay conditions must be thoroughly examined. In this study we expanded upon the capabilities of this assay by including antibiotics and antifolates in the drug panel and testing folic acid-free growth conditions. To do this, we evaluated a more expansive panel of antimalarials in combination with various drug assay culture conditions commonly used in drug sensitivity screening for their activity against Plasmodium falciparum strains D6 and W2. The detection and quantitation limits of the MSF assay were 0.04 to 0.08% and approximately 0.5% parasitemia, respectively. The MSF assay quality was significantly robust, displaying a Z' range of 0.73 to 0.95. The 50% inhibitory concentrations for each drug and culture condition combination were determined by using the MSF assay. Compared to the standard [(3)H]hypoxanthine assay, the MSF assay displayed the expected parasite drug resistance patterns with a high degree of global and phenotypic correlation (r(2) >/= 0.9238), regardless of which culture condition combination was used. In conclusion, the MSF assay allows for reliable one-plate high-throughput, automated malaria in vitro susceptibility testing without the expense, time consumption, and hazard of other screening assays.
|
Antimalarial activity against Plasmodium falciparum W2 as reduced [3H]hypoxanthine uptake after 72 hrs
|
Plasmodium falciparum
|
5.5
ug.mL-1
|
|
Journal : Antimicrob. Agents Chemother.
Title : Assessment and continued validation of the malaria SYBR green I-based fluorescence assay for use in malaria drug screening.
Year : 2007
Volume : 51
Issue : 6
First Page : 1926
Last Page : 1933
Authors : Johnson JD, Dennull RA, Gerena L, Lopez-Sanchez M, Roncal NE, Waters NC.
Abstract : Several new fluorescence malaria in vitro drug susceptibility microtiter plate assays that detect the presence of malarial DNA in infected erythrocytes have recently been reported, in contrast to traditional isotopic screens that involve radioactive substrate incorporation to measure in vitro malaria growth inhibition. We have assessed and further characterized the malaria SYBR Green I-based fluorescence (MSF) assay for its ability to monitor drug resistance. In order to use the MSF assay as a drug screen, all assay conditions must be thoroughly examined. In this study we expanded upon the capabilities of this assay by including antibiotics and antifolates in the drug panel and testing folic acid-free growth conditions. To do this, we evaluated a more expansive panel of antimalarials in combination with various drug assay culture conditions commonly used in drug sensitivity screening for their activity against Plasmodium falciparum strains D6 and W2. The detection and quantitation limits of the MSF assay were 0.04 to 0.08% and approximately 0.5% parasitemia, respectively. The MSF assay quality was significantly robust, displaying a Z' range of 0.73 to 0.95. The 50% inhibitory concentrations for each drug and culture condition combination were determined by using the MSF assay. Compared to the standard [(3)H]hypoxanthine assay, the MSF assay displayed the expected parasite drug resistance patterns with a high degree of global and phenotypic correlation (r(2) >/= 0.9238), regardless of which culture condition combination was used. In conclusion, the MSF assay allows for reliable one-plate high-throughput, automated malaria in vitro susceptibility testing without the expense, time consumption, and hazard of other screening assays.
|
Antimalarial activity after 96 hrs against Plasmodium falciparum 7G8 C1 mutant CRT/MDR1 by [3H]hypoxanthine uptake
|
Plasmodium falciparum
|
141.8
nM
|
|
Journal : J. Biol. Chem.
Title : In vitro efficacy, resistance selection, and structural modeling studies implicate the malarial parasite apicoplast as the target of azithromycin.
Year : 2007
Volume : 282
Issue : 4
First Page : 2494
Last Page : 2504
Authors : Sidhu AB, Sun Q, Nkrumah LJ, Dunne MW, Sacchettini JC, Fidock DA.
Abstract : Azithromycin (AZ), a broad-spectrum antibacterial macrolide that inhibits protein synthesis, also manifests reasonable efficacy as an antimalarial. Its mode of action against malarial parasites, however, has remained undefined. Our in vitro investigations with the human malarial parasite Plasmodium falciparum document a remarkable increase in AZ potency when exposure is prolonged from one to two generations of intraerythrocytic growth, with AZ producing 50% inhibition of parasite growth at concentrations in the mid to low nanomolar range. In our culture-adapted lines, AZ displayed no synergy with chloroquine (CQ), amodiaquine, or artesunate. AZ activity was also unaffected by mutations in the pfcrt (P. falciparum chloroquine resistance transporter) or pfmdr1 (P. falciparum multidrug resistance-1) drug resistance loci, as determined using transgenic lines. We have selected mutant, AZ-resistant 7G8 and Dd2 parasite lines. In the AZ-resistant 7G8 line, the bacterial-like apicoplast large subunit ribosomal RNA harbored a U438C mutation in domain I. Both AZ-resistant lines revealed a G76V mutation in a conserved region of the apicoplast-encoded P. falciparum ribosomal protein L4 (PfRpl4). This protein is predicted to associate with the nuclear genome-encoded P. falciparum ribosomal protein L22 (PfRpl22) and the large subunit rRNA to form the 50 S ribosome polypeptide exit tunnel that can be occupied by AZ. The PfRpl22 sequence remained unchanged. Molecular modeling of mutant PfRpl4 with AZ suggests an altered orientation of the L75 side chain that could preclude AZ binding. These data imply that AZ acts on the apicoplast bacterial-like translation machinery and identify Pfrpl4 as a potential marker of resistance.
|
Antimalarial activity after 96 hrs against Plasmodium falciparum Dd2 C1 mutant CRT/MDR1 by [3H]hypoxanthine uptake
|
Plasmodium falciparum
|
95.7
nM
|
|
Journal : J. Biol. Chem.
Title : In vitro efficacy, resistance selection, and structural modeling studies implicate the malarial parasite apicoplast as the target of azithromycin.
Year : 2007
Volume : 282
Issue : 4
First Page : 2494
Last Page : 2504
Authors : Sidhu AB, Sun Q, Nkrumah LJ, Dunne MW, Sacchettini JC, Fidock DA.
Abstract : Azithromycin (AZ), a broad-spectrum antibacterial macrolide that inhibits protein synthesis, also manifests reasonable efficacy as an antimalarial. Its mode of action against malarial parasites, however, has remained undefined. Our in vitro investigations with the human malarial parasite Plasmodium falciparum document a remarkable increase in AZ potency when exposure is prolonged from one to two generations of intraerythrocytic growth, with AZ producing 50% inhibition of parasite growth at concentrations in the mid to low nanomolar range. In our culture-adapted lines, AZ displayed no synergy with chloroquine (CQ), amodiaquine, or artesunate. AZ activity was also unaffected by mutations in the pfcrt (P. falciparum chloroquine resistance transporter) or pfmdr1 (P. falciparum multidrug resistance-1) drug resistance loci, as determined using transgenic lines. We have selected mutant, AZ-resistant 7G8 and Dd2 parasite lines. In the AZ-resistant 7G8 line, the bacterial-like apicoplast large subunit ribosomal RNA harbored a U438C mutation in domain I. Both AZ-resistant lines revealed a G76V mutation in a conserved region of the apicoplast-encoded P. falciparum ribosomal protein L4 (PfRpl4). This protein is predicted to associate with the nuclear genome-encoded P. falciparum ribosomal protein L22 (PfRpl22) and the large subunit rRNA to form the 50 S ribosome polypeptide exit tunnel that can be occupied by AZ. The PfRpl22 sequence remained unchanged. Molecular modeling of mutant PfRpl4 with AZ suggests an altered orientation of the L75 side chain that could preclude AZ binding. These data imply that AZ acts on the apicoplast bacterial-like translation machinery and identify Pfrpl4 as a potential marker of resistance.
|
Antimalarial activity after 96 hrs against Plasmodium falciparum Dd2 by [3H]hypoxanthine uptake
|
Plasmodium falciparum
|
103.4
nM
|
|
Journal : J. Biol. Chem.
Title : In vitro efficacy, resistance selection, and structural modeling studies implicate the malarial parasite apicoplast as the target of azithromycin.
Year : 2007
Volume : 282
Issue : 4
First Page : 2494
Last Page : 2504
Authors : Sidhu AB, Sun Q, Nkrumah LJ, Dunne MW, Sacchettini JC, Fidock DA.
Abstract : Azithromycin (AZ), a broad-spectrum antibacterial macrolide that inhibits protein synthesis, also manifests reasonable efficacy as an antimalarial. Its mode of action against malarial parasites, however, has remained undefined. Our in vitro investigations with the human malarial parasite Plasmodium falciparum document a remarkable increase in AZ potency when exposure is prolonged from one to two generations of intraerythrocytic growth, with AZ producing 50% inhibition of parasite growth at concentrations in the mid to low nanomolar range. In our culture-adapted lines, AZ displayed no synergy with chloroquine (CQ), amodiaquine, or artesunate. AZ activity was also unaffected by mutations in the pfcrt (P. falciparum chloroquine resistance transporter) or pfmdr1 (P. falciparum multidrug resistance-1) drug resistance loci, as determined using transgenic lines. We have selected mutant, AZ-resistant 7G8 and Dd2 parasite lines. In the AZ-resistant 7G8 line, the bacterial-like apicoplast large subunit ribosomal RNA harbored a U438C mutation in domain I. Both AZ-resistant lines revealed a G76V mutation in a conserved region of the apicoplast-encoded P. falciparum ribosomal protein L4 (PfRpl4). This protein is predicted to associate with the nuclear genome-encoded P. falciparum ribosomal protein L22 (PfRpl22) and the large subunit rRNA to form the 50 S ribosome polypeptide exit tunnel that can be occupied by AZ. The PfRpl22 sequence remained unchanged. Molecular modeling of mutant PfRpl4 with AZ suggests an altered orientation of the L75 side chain that could preclude AZ binding. These data imply that AZ acts on the apicoplast bacterial-like translation machinery and identify Pfrpl4 as a potential marker of resistance.
|
Antimalarial activity after 96hrs against Plasmodium falciparum 7G8 by [3H]hypoxanthine uptake
|
Plasmodium falciparum
|
228.1
nM
|
|
Journal : J. Biol. Chem.
Title : In vitro efficacy, resistance selection, and structural modeling studies implicate the malarial parasite apicoplast as the target of azithromycin.
Year : 2007
Volume : 282
Issue : 4
First Page : 2494
Last Page : 2504
Authors : Sidhu AB, Sun Q, Nkrumah LJ, Dunne MW, Sacchettini JC, Fidock DA.
Abstract : Azithromycin (AZ), a broad-spectrum antibacterial macrolide that inhibits protein synthesis, also manifests reasonable efficacy as an antimalarial. Its mode of action against malarial parasites, however, has remained undefined. Our in vitro investigations with the human malarial parasite Plasmodium falciparum document a remarkable increase in AZ potency when exposure is prolonged from one to two generations of intraerythrocytic growth, with AZ producing 50% inhibition of parasite growth at concentrations in the mid to low nanomolar range. In our culture-adapted lines, AZ displayed no synergy with chloroquine (CQ), amodiaquine, or artesunate. AZ activity was also unaffected by mutations in the pfcrt (P. falciparum chloroquine resistance transporter) or pfmdr1 (P. falciparum multidrug resistance-1) drug resistance loci, as determined using transgenic lines. We have selected mutant, AZ-resistant 7G8 and Dd2 parasite lines. In the AZ-resistant 7G8 line, the bacterial-like apicoplast large subunit ribosomal RNA harbored a U438C mutation in domain I. Both AZ-resistant lines revealed a G76V mutation in a conserved region of the apicoplast-encoded P. falciparum ribosomal protein L4 (PfRpl4). This protein is predicted to associate with the nuclear genome-encoded P. falciparum ribosomal protein L22 (PfRpl22) and the large subunit rRNA to form the 50 S ribosome polypeptide exit tunnel that can be occupied by AZ. The PfRpl22 sequence remained unchanged. Molecular modeling of mutant PfRpl4 with AZ suggests an altered orientation of the L75 side chain that could preclude AZ binding. These data imply that AZ acts on the apicoplast bacterial-like translation machinery and identify Pfrpl4 as a potential marker of resistance.
|
Antimalarial activity after 96 hrs against Plasmodium falciparum GCO3 by [3H]hypoxanthine uptake
|
Plasmodium falciparum
|
43.3
nM
|
|
Journal : J. Biol. Chem.
Title : In vitro efficacy, resistance selection, and structural modeling studies implicate the malarial parasite apicoplast as the target of azithromycin.
Year : 2007
Volume : 282
Issue : 4
First Page : 2494
Last Page : 2504
Authors : Sidhu AB, Sun Q, Nkrumah LJ, Dunne MW, Sacchettini JC, Fidock DA.
Abstract : Azithromycin (AZ), a broad-spectrum antibacterial macrolide that inhibits protein synthesis, also manifests reasonable efficacy as an antimalarial. Its mode of action against malarial parasites, however, has remained undefined. Our in vitro investigations with the human malarial parasite Plasmodium falciparum document a remarkable increase in AZ potency when exposure is prolonged from one to two generations of intraerythrocytic growth, with AZ producing 50% inhibition of parasite growth at concentrations in the mid to low nanomolar range. In our culture-adapted lines, AZ displayed no synergy with chloroquine (CQ), amodiaquine, or artesunate. AZ activity was also unaffected by mutations in the pfcrt (P. falciparum chloroquine resistance transporter) or pfmdr1 (P. falciparum multidrug resistance-1) drug resistance loci, as determined using transgenic lines. We have selected mutant, AZ-resistant 7G8 and Dd2 parasite lines. In the AZ-resistant 7G8 line, the bacterial-like apicoplast large subunit ribosomal RNA harbored a U438C mutation in domain I. Both AZ-resistant lines revealed a G76V mutation in a conserved region of the apicoplast-encoded P. falciparum ribosomal protein L4 (PfRpl4). This protein is predicted to associate with the nuclear genome-encoded P. falciparum ribosomal protein L22 (PfRpl22) and the large subunit rRNA to form the 50 S ribosome polypeptide exit tunnel that can be occupied by AZ. The PfRpl22 sequence remained unchanged. Molecular modeling of mutant PfRpl4 with AZ suggests an altered orientation of the L75 side chain that could preclude AZ binding. These data imply that AZ acts on the apicoplast bacterial-like translation machinery and identify Pfrpl4 as a potential marker of resistance.
|
Antimalarial activity after 96 hrs against Plasmodium falciparum Dd2 T76K1 mutant CRT/MDR1 by [3H]hypoxanthine uptake
|
Plasmodium falciparum
|
121.8
nM
|
|
Journal : J. Biol. Chem.
Title : In vitro efficacy, resistance selection, and structural modeling studies implicate the malarial parasite apicoplast as the target of azithromycin.
Year : 2007
Volume : 282
Issue : 4
First Page : 2494
Last Page : 2504
Authors : Sidhu AB, Sun Q, Nkrumah LJ, Dunne MW, Sacchettini JC, Fidock DA.
Abstract : Azithromycin (AZ), a broad-spectrum antibacterial macrolide that inhibits protein synthesis, also manifests reasonable efficacy as an antimalarial. Its mode of action against malarial parasites, however, has remained undefined. Our in vitro investigations with the human malarial parasite Plasmodium falciparum document a remarkable increase in AZ potency when exposure is prolonged from one to two generations of intraerythrocytic growth, with AZ producing 50% inhibition of parasite growth at concentrations in the mid to low nanomolar range. In our culture-adapted lines, AZ displayed no synergy with chloroquine (CQ), amodiaquine, or artesunate. AZ activity was also unaffected by mutations in the pfcrt (P. falciparum chloroquine resistance transporter) or pfmdr1 (P. falciparum multidrug resistance-1) drug resistance loci, as determined using transgenic lines. We have selected mutant, AZ-resistant 7G8 and Dd2 parasite lines. In the AZ-resistant 7G8 line, the bacterial-like apicoplast large subunit ribosomal RNA harbored a U438C mutation in domain I. Both AZ-resistant lines revealed a G76V mutation in a conserved region of the apicoplast-encoded P. falciparum ribosomal protein L4 (PfRpl4). This protein is predicted to associate with the nuclear genome-encoded P. falciparum ribosomal protein L22 (PfRpl22) and the large subunit rRNA to form the 50 S ribosome polypeptide exit tunnel that can be occupied by AZ. The PfRpl22 sequence remained unchanged. Molecular modeling of mutant PfRpl4 with AZ suggests an altered orientation of the L75 side chain that could preclude AZ binding. These data imply that AZ acts on the apicoplast bacterial-like translation machinery and identify Pfrpl4 as a potential marker of resistance.
|
Antimalarial activity after 96 hrs against Plasmodium falciparum 7G8 T76K1 mutant CRT/MDR1 by [3H]hypoxanthine uptake
|
Plasmodium falciparum
|
114.8
nM
|
|
Journal : J. Biol. Chem.
Title : In vitro efficacy, resistance selection, and structural modeling studies implicate the malarial parasite apicoplast as the target of azithromycin.
Year : 2007
Volume : 282
Issue : 4
First Page : 2494
Last Page : 2504
Authors : Sidhu AB, Sun Q, Nkrumah LJ, Dunne MW, Sacchettini JC, Fidock DA.
Abstract : Azithromycin (AZ), a broad-spectrum antibacterial macrolide that inhibits protein synthesis, also manifests reasonable efficacy as an antimalarial. Its mode of action against malarial parasites, however, has remained undefined. Our in vitro investigations with the human malarial parasite Plasmodium falciparum document a remarkable increase in AZ potency when exposure is prolonged from one to two generations of intraerythrocytic growth, with AZ producing 50% inhibition of parasite growth at concentrations in the mid to low nanomolar range. In our culture-adapted lines, AZ displayed no synergy with chloroquine (CQ), amodiaquine, or artesunate. AZ activity was also unaffected by mutations in the pfcrt (P. falciparum chloroquine resistance transporter) or pfmdr1 (P. falciparum multidrug resistance-1) drug resistance loci, as determined using transgenic lines. We have selected mutant, AZ-resistant 7G8 and Dd2 parasite lines. In the AZ-resistant 7G8 line, the bacterial-like apicoplast large subunit ribosomal RNA harbored a U438C mutation in domain I. Both AZ-resistant lines revealed a G76V mutation in a conserved region of the apicoplast-encoded P. falciparum ribosomal protein L4 (PfRpl4). This protein is predicted to associate with the nuclear genome-encoded P. falciparum ribosomal protein L22 (PfRpl22) and the large subunit rRNA to form the 50 S ribosome polypeptide exit tunnel that can be occupied by AZ. The PfRpl22 sequence remained unchanged. Molecular modeling of mutant PfRpl4 with AZ suggests an altered orientation of the L75 side chain that could preclude AZ binding. These data imply that AZ acts on the apicoplast bacterial-like translation machinery and identify Pfrpl4 as a potential marker of resistance.
|
Antimalarial activity after 96hrs against Plasmodium falciparum GCO3 C2 mutant CRT/MDR1 by [3H]hypoxanthine uptake
|
Plasmodium falciparum
|
48.0
nM
|
|
Journal : J. Biol. Chem.
Title : In vitro efficacy, resistance selection, and structural modeling studies implicate the malarial parasite apicoplast as the target of azithromycin.
Year : 2007
Volume : 282
Issue : 4
First Page : 2494
Last Page : 2504
Authors : Sidhu AB, Sun Q, Nkrumah LJ, Dunne MW, Sacchettini JC, Fidock DA.
Abstract : Azithromycin (AZ), a broad-spectrum antibacterial macrolide that inhibits protein synthesis, also manifests reasonable efficacy as an antimalarial. Its mode of action against malarial parasites, however, has remained undefined. Our in vitro investigations with the human malarial parasite Plasmodium falciparum document a remarkable increase in AZ potency when exposure is prolonged from one to two generations of intraerythrocytic growth, with AZ producing 50% inhibition of parasite growth at concentrations in the mid to low nanomolar range. In our culture-adapted lines, AZ displayed no synergy with chloroquine (CQ), amodiaquine, or artesunate. AZ activity was also unaffected by mutations in the pfcrt (P. falciparum chloroquine resistance transporter) or pfmdr1 (P. falciparum multidrug resistance-1) drug resistance loci, as determined using transgenic lines. We have selected mutant, AZ-resistant 7G8 and Dd2 parasite lines. In the AZ-resistant 7G8 line, the bacterial-like apicoplast large subunit ribosomal RNA harbored a U438C mutation in domain I. Both AZ-resistant lines revealed a G76V mutation in a conserved region of the apicoplast-encoded P. falciparum ribosomal protein L4 (PfRpl4). This protein is predicted to associate with the nuclear genome-encoded P. falciparum ribosomal protein L22 (PfRpl22) and the large subunit rRNA to form the 50 S ribosome polypeptide exit tunnel that can be occupied by AZ. The PfRpl22 sequence remained unchanged. Molecular modeling of mutant PfRpl4 with AZ suggests an altered orientation of the L75 side chain that could preclude AZ binding. These data imply that AZ acts on the apicoplast bacterial-like translation machinery and identify Pfrpl4 as a potential marker of resistance.
|
Antimalarial activity after 96 hrs against Plasmodium falciparum GCO3 C4 mutant CRT/MDR1 by [3H]hypoxanthine uptake
|
Plasmodium falciparum
|
66.7
nM
|
|
Journal : J. Biol. Chem.
Title : In vitro efficacy, resistance selection, and structural modeling studies implicate the malarial parasite apicoplast as the target of azithromycin.
Year : 2007
Volume : 282
Issue : 4
First Page : 2494
Last Page : 2504
Authors : Sidhu AB, Sun Q, Nkrumah LJ, Dunne MW, Sacchettini JC, Fidock DA.
Abstract : Azithromycin (AZ), a broad-spectrum antibacterial macrolide that inhibits protein synthesis, also manifests reasonable efficacy as an antimalarial. Its mode of action against malarial parasites, however, has remained undefined. Our in vitro investigations with the human malarial parasite Plasmodium falciparum document a remarkable increase in AZ potency when exposure is prolonged from one to two generations of intraerythrocytic growth, with AZ producing 50% inhibition of parasite growth at concentrations in the mid to low nanomolar range. In our culture-adapted lines, AZ displayed no synergy with chloroquine (CQ), amodiaquine, or artesunate. AZ activity was also unaffected by mutations in the pfcrt (P. falciparum chloroquine resistance transporter) or pfmdr1 (P. falciparum multidrug resistance-1) drug resistance loci, as determined using transgenic lines. We have selected mutant, AZ-resistant 7G8 and Dd2 parasite lines. In the AZ-resistant 7G8 line, the bacterial-like apicoplast large subunit ribosomal RNA harbored a U438C mutation in domain I. Both AZ-resistant lines revealed a G76V mutation in a conserved region of the apicoplast-encoded P. falciparum ribosomal protein L4 (PfRpl4). This protein is predicted to associate with the nuclear genome-encoded P. falciparum ribosomal protein L22 (PfRpl22) and the large subunit rRNA to form the 50 S ribosome polypeptide exit tunnel that can be occupied by AZ. The PfRpl22 sequence remained unchanged. Molecular modeling of mutant PfRpl4 with AZ suggests an altered orientation of the L75 side chain that could preclude AZ binding. These data imply that AZ acts on the apicoplast bacterial-like translation machinery and identify Pfrpl4 as a potential marker of resistance.
|
Antimalarial activity after 96 hrs against Plasmodium falciparum GCO3 C6 mutant CRT/MDR1 by [3H]hypoxanthine uptake
|
Plasmodium falciparum
|
76.7
nM
|
|
Journal : J. Biol. Chem.
Title : In vitro efficacy, resistance selection, and structural modeling studies implicate the malarial parasite apicoplast as the target of azithromycin.
Year : 2007
Volume : 282
Issue : 4
First Page : 2494
Last Page : 2504
Authors : Sidhu AB, Sun Q, Nkrumah LJ, Dunne MW, Sacchettini JC, Fidock DA.
Abstract : Azithromycin (AZ), a broad-spectrum antibacterial macrolide that inhibits protein synthesis, also manifests reasonable efficacy as an antimalarial. Its mode of action against malarial parasites, however, has remained undefined. Our in vitro investigations with the human malarial parasite Plasmodium falciparum document a remarkable increase in AZ potency when exposure is prolonged from one to two generations of intraerythrocytic growth, with AZ producing 50% inhibition of parasite growth at concentrations in the mid to low nanomolar range. In our culture-adapted lines, AZ displayed no synergy with chloroquine (CQ), amodiaquine, or artesunate. AZ activity was also unaffected by mutations in the pfcrt (P. falciparum chloroquine resistance transporter) or pfmdr1 (P. falciparum multidrug resistance-1) drug resistance loci, as determined using transgenic lines. We have selected mutant, AZ-resistant 7G8 and Dd2 parasite lines. In the AZ-resistant 7G8 line, the bacterial-like apicoplast large subunit ribosomal RNA harbored a U438C mutation in domain I. Both AZ-resistant lines revealed a G76V mutation in a conserved region of the apicoplast-encoded P. falciparum ribosomal protein L4 (PfRpl4). This protein is predicted to associate with the nuclear genome-encoded P. falciparum ribosomal protein L22 (PfRpl22) and the large subunit rRNA to form the 50 S ribosome polypeptide exit tunnel that can be occupied by AZ. The PfRpl22 sequence remained unchanged. Molecular modeling of mutant PfRpl4 with AZ suggests an altered orientation of the L75 side chain that could preclude AZ binding. These data imply that AZ acts on the apicoplast bacterial-like translation machinery and identify Pfrpl4 as a potential marker of resistance.
|
Antimalarial activity after 96 hrs against Plasmodium falciparum GCO3 SDD mutant CRT/MDR1 by [3H]hypoxanthine uptake
|
Plasmodium falciparum
|
63.3
nM
|
|
Journal : J. Biol. Chem.
Title : In vitro efficacy, resistance selection, and structural modeling studies implicate the malarial parasite apicoplast as the target of azithromycin.
Year : 2007
Volume : 282
Issue : 4
First Page : 2494
Last Page : 2504
Authors : Sidhu AB, Sun Q, Nkrumah LJ, Dunne MW, Sacchettini JC, Fidock DA.
Abstract : Azithromycin (AZ), a broad-spectrum antibacterial macrolide that inhibits protein synthesis, also manifests reasonable efficacy as an antimalarial. Its mode of action against malarial parasites, however, has remained undefined. Our in vitro investigations with the human malarial parasite Plasmodium falciparum document a remarkable increase in AZ potency when exposure is prolonged from one to two generations of intraerythrocytic growth, with AZ producing 50% inhibition of parasite growth at concentrations in the mid to low nanomolar range. In our culture-adapted lines, AZ displayed no synergy with chloroquine (CQ), amodiaquine, or artesunate. AZ activity was also unaffected by mutations in the pfcrt (P. falciparum chloroquine resistance transporter) or pfmdr1 (P. falciparum multidrug resistance-1) drug resistance loci, as determined using transgenic lines. We have selected mutant, AZ-resistant 7G8 and Dd2 parasite lines. In the AZ-resistant 7G8 line, the bacterial-like apicoplast large subunit ribosomal RNA harbored a U438C mutation in domain I. Both AZ-resistant lines revealed a G76V mutation in a conserved region of the apicoplast-encoded P. falciparum ribosomal protein L4 (PfRpl4). This protein is predicted to associate with the nuclear genome-encoded P. falciparum ribosomal protein L22 (PfRpl22) and the large subunit rRNA to form the 50 S ribosome polypeptide exit tunnel that can be occupied by AZ. The PfRpl22 sequence remained unchanged. Molecular modeling of mutant PfRpl4 with AZ suggests an altered orientation of the L75 side chain that could preclude AZ binding. These data imply that AZ acts on the apicoplast bacterial-like translation machinery and identify Pfrpl4 as a potential marker of resistance.
|
Antimalarial activity after 96 hrs against Plasmodium falciparum GCO3 SND mutant CRT/MDR1 by [3H]hypoxanthine uptake
|
Plasmodium falciparum
|
47.8
nM
|
|
Journal : J. Biol. Chem.
Title : In vitro efficacy, resistance selection, and structural modeling studies implicate the malarial parasite apicoplast as the target of azithromycin.
Year : 2007
Volume : 282
Issue : 4
First Page : 2494
Last Page : 2504
Authors : Sidhu AB, Sun Q, Nkrumah LJ, Dunne MW, Sacchettini JC, Fidock DA.
Abstract : Azithromycin (AZ), a broad-spectrum antibacterial macrolide that inhibits protein synthesis, also manifests reasonable efficacy as an antimalarial. Its mode of action against malarial parasites, however, has remained undefined. Our in vitro investigations with the human malarial parasite Plasmodium falciparum document a remarkable increase in AZ potency when exposure is prolonged from one to two generations of intraerythrocytic growth, with AZ producing 50% inhibition of parasite growth at concentrations in the mid to low nanomolar range. In our culture-adapted lines, AZ displayed no synergy with chloroquine (CQ), amodiaquine, or artesunate. AZ activity was also unaffected by mutations in the pfcrt (P. falciparum chloroquine resistance transporter) or pfmdr1 (P. falciparum multidrug resistance-1) drug resistance loci, as determined using transgenic lines. We have selected mutant, AZ-resistant 7G8 and Dd2 parasite lines. In the AZ-resistant 7G8 line, the bacterial-like apicoplast large subunit ribosomal RNA harbored a U438C mutation in domain I. Both AZ-resistant lines revealed a G76V mutation in a conserved region of the apicoplast-encoded P. falciparum ribosomal protein L4 (PfRpl4). This protein is predicted to associate with the nuclear genome-encoded P. falciparum ribosomal protein L22 (PfRpl22) and the large subunit rRNA to form the 50 S ribosome polypeptide exit tunnel that can be occupied by AZ. The PfRpl22 sequence remained unchanged. Molecular modeling of mutant PfRpl4 with AZ suggests an altered orientation of the L75 side chain that could preclude AZ binding. These data imply that AZ acts on the apicoplast bacterial-like translation machinery and identify Pfrpl4 as a potential marker of resistance.
|
Antimalarial activity after 96 hrs against Plasmodium falciparum GCO3 CDY mutant CRT/MDR1 by [3H]hypoxanthine uptake
|
Plasmodium falciparum
|
70.2
nM
|
|
Journal : J. Biol. Chem.
Title : In vitro efficacy, resistance selection, and structural modeling studies implicate the malarial parasite apicoplast as the target of azithromycin.
Year : 2007
Volume : 282
Issue : 4
First Page : 2494
Last Page : 2504
Authors : Sidhu AB, Sun Q, Nkrumah LJ, Dunne MW, Sacchettini JC, Fidock DA.
Abstract : Azithromycin (AZ), a broad-spectrum antibacterial macrolide that inhibits protein synthesis, also manifests reasonable efficacy as an antimalarial. Its mode of action against malarial parasites, however, has remained undefined. Our in vitro investigations with the human malarial parasite Plasmodium falciparum document a remarkable increase in AZ potency when exposure is prolonged from one to two generations of intraerythrocytic growth, with AZ producing 50% inhibition of parasite growth at concentrations in the mid to low nanomolar range. In our culture-adapted lines, AZ displayed no synergy with chloroquine (CQ), amodiaquine, or artesunate. AZ activity was also unaffected by mutations in the pfcrt (P. falciparum chloroquine resistance transporter) or pfmdr1 (P. falciparum multidrug resistance-1) drug resistance loci, as determined using transgenic lines. We have selected mutant, AZ-resistant 7G8 and Dd2 parasite lines. In the AZ-resistant 7G8 line, the bacterial-like apicoplast large subunit ribosomal RNA harbored a U438C mutation in domain I. Both AZ-resistant lines revealed a G76V mutation in a conserved region of the apicoplast-encoded P. falciparum ribosomal protein L4 (PfRpl4). This protein is predicted to associate with the nuclear genome-encoded P. falciparum ribosomal protein L22 (PfRpl22) and the large subunit rRNA to form the 50 S ribosome polypeptide exit tunnel that can be occupied by AZ. The PfRpl22 sequence remained unchanged. Molecular modeling of mutant PfRpl4 with AZ suggests an altered orientation of the L75 side chain that could preclude AZ binding. These data imply that AZ acts on the apicoplast bacterial-like translation machinery and identify Pfrpl4 as a potential marker of resistance.
|
Antimalarial activity after 96 hrs against Plasmodium falciparum 3BA6 by [3H]hypoxanthine uptake
|
Plasmodium falciparum
|
180.3
nM
|
|
Journal : J. Biol. Chem.
Title : In vitro efficacy, resistance selection, and structural modeling studies implicate the malarial parasite apicoplast as the target of azithromycin.
Year : 2007
Volume : 282
Issue : 4
First Page : 2494
Last Page : 2504
Authors : Sidhu AB, Sun Q, Nkrumah LJ, Dunne MW, Sacchettini JC, Fidock DA.
Abstract : Azithromycin (AZ), a broad-spectrum antibacterial macrolide that inhibits protein synthesis, also manifests reasonable efficacy as an antimalarial. Its mode of action against malarial parasites, however, has remained undefined. Our in vitro investigations with the human malarial parasite Plasmodium falciparum document a remarkable increase in AZ potency when exposure is prolonged from one to two generations of intraerythrocytic growth, with AZ producing 50% inhibition of parasite growth at concentrations in the mid to low nanomolar range. In our culture-adapted lines, AZ displayed no synergy with chloroquine (CQ), amodiaquine, or artesunate. AZ activity was also unaffected by mutations in the pfcrt (P. falciparum chloroquine resistance transporter) or pfmdr1 (P. falciparum multidrug resistance-1) drug resistance loci, as determined using transgenic lines. We have selected mutant, AZ-resistant 7G8 and Dd2 parasite lines. In the AZ-resistant 7G8 line, the bacterial-like apicoplast large subunit ribosomal RNA harbored a U438C mutation in domain I. Both AZ-resistant lines revealed a G76V mutation in a conserved region of the apicoplast-encoded P. falciparum ribosomal protein L4 (PfRpl4). This protein is predicted to associate with the nuclear genome-encoded P. falciparum ribosomal protein L22 (PfRpl22) and the large subunit rRNA to form the 50 S ribosome polypeptide exit tunnel that can be occupied by AZ. The PfRpl22 sequence remained unchanged. Molecular modeling of mutant PfRpl4 with AZ suggests an altered orientation of the L75 side chain that could preclude AZ binding. These data imply that AZ acts on the apicoplast bacterial-like translation machinery and identify Pfrpl4 as a potential marker of resistance.
|
Antimalarial activity against Plasmodium falciparum 3BA6 SDD with CRT and MDR1 mutation after 96 hrs in [3H]hypoxanthine uptake
|
Plasmodium falciparum
|
154.7
nM
|
|
Journal : J. Biol. Chem.
Title : In vitro efficacy, resistance selection, and structural modeling studies implicate the malarial parasite apicoplast as the target of azithromycin.
Year : 2007
Volume : 282
Issue : 4
First Page : 2494
Last Page : 2504
Authors : Sidhu AB, Sun Q, Nkrumah LJ, Dunne MW, Sacchettini JC, Fidock DA.
Abstract : Azithromycin (AZ), a broad-spectrum antibacterial macrolide that inhibits protein synthesis, also manifests reasonable efficacy as an antimalarial. Its mode of action against malarial parasites, however, has remained undefined. Our in vitro investigations with the human malarial parasite Plasmodium falciparum document a remarkable increase in AZ potency when exposure is prolonged from one to two generations of intraerythrocytic growth, with AZ producing 50% inhibition of parasite growth at concentrations in the mid to low nanomolar range. In our culture-adapted lines, AZ displayed no synergy with chloroquine (CQ), amodiaquine, or artesunate. AZ activity was also unaffected by mutations in the pfcrt (P. falciparum chloroquine resistance transporter) or pfmdr1 (P. falciparum multidrug resistance-1) drug resistance loci, as determined using transgenic lines. We have selected mutant, AZ-resistant 7G8 and Dd2 parasite lines. In the AZ-resistant 7G8 line, the bacterial-like apicoplast large subunit ribosomal RNA harbored a U438C mutation in domain I. Both AZ-resistant lines revealed a G76V mutation in a conserved region of the apicoplast-encoded P. falciparum ribosomal protein L4 (PfRpl4). This protein is predicted to associate with the nuclear genome-encoded P. falciparum ribosomal protein L22 (PfRpl22) and the large subunit rRNA to form the 50 S ribosome polypeptide exit tunnel that can be occupied by AZ. The PfRpl22 sequence remained unchanged. Molecular modeling of mutant PfRpl4 with AZ suggests an altered orientation of the L75 side chain that could preclude AZ binding. These data imply that AZ acts on the apicoplast bacterial-like translation machinery and identify Pfrpl4 as a potential marker of resistance.
|
Antimalarial activity after 96 hrs against Plasmodium falciparum 3BA6 SND mutant CRT/MDR1 by [3H]hypoxanthine uptake
|
Plasmodium falciparum
|
157.9
nM
|
|
Journal : J. Biol. Chem.
Title : In vitro efficacy, resistance selection, and structural modeling studies implicate the malarial parasite apicoplast as the target of azithromycin.
Year : 2007
Volume : 282
Issue : 4
First Page : 2494
Last Page : 2504
Authors : Sidhu AB, Sun Q, Nkrumah LJ, Dunne MW, Sacchettini JC, Fidock DA.
Abstract : Azithromycin (AZ), a broad-spectrum antibacterial macrolide that inhibits protein synthesis, also manifests reasonable efficacy as an antimalarial. Its mode of action against malarial parasites, however, has remained undefined. Our in vitro investigations with the human malarial parasite Plasmodium falciparum document a remarkable increase in AZ potency when exposure is prolonged from one to two generations of intraerythrocytic growth, with AZ producing 50% inhibition of parasite growth at concentrations in the mid to low nanomolar range. In our culture-adapted lines, AZ displayed no synergy with chloroquine (CQ), amodiaquine, or artesunate. AZ activity was also unaffected by mutations in the pfcrt (P. falciparum chloroquine resistance transporter) or pfmdr1 (P. falciparum multidrug resistance-1) drug resistance loci, as determined using transgenic lines. We have selected mutant, AZ-resistant 7G8 and Dd2 parasite lines. In the AZ-resistant 7G8 line, the bacterial-like apicoplast large subunit ribosomal RNA harbored a U438C mutation in domain I. Both AZ-resistant lines revealed a G76V mutation in a conserved region of the apicoplast-encoded P. falciparum ribosomal protein L4 (PfRpl4). This protein is predicted to associate with the nuclear genome-encoded P. falciparum ribosomal protein L22 (PfRpl22) and the large subunit rRNA to form the 50 S ribosome polypeptide exit tunnel that can be occupied by AZ. The PfRpl22 sequence remained unchanged. Molecular modeling of mutant PfRpl4 with AZ suggests an altered orientation of the L75 side chain that could preclude AZ binding. These data imply that AZ acts on the apicoplast bacterial-like translation machinery and identify Pfrpl4 as a potential marker of resistance.
|
Antimalarial activity after 96 hrs against Plasmodium falciparum 3BA6 CDY mutant CRT/MDR1 by [3H]hypoxanthine uptake
|
Plasmodium falciparum
|
194.2
nM
|
|
Journal : J. Biol. Chem.
Title : In vitro efficacy, resistance selection, and structural modeling studies implicate the malarial parasite apicoplast as the target of azithromycin.
Year : 2007
Volume : 282
Issue : 4
First Page : 2494
Last Page : 2504
Authors : Sidhu AB, Sun Q, Nkrumah LJ, Dunne MW, Sacchettini JC, Fidock DA.
Abstract : Azithromycin (AZ), a broad-spectrum antibacterial macrolide that inhibits protein synthesis, also manifests reasonable efficacy as an antimalarial. Its mode of action against malarial parasites, however, has remained undefined. Our in vitro investigations with the human malarial parasite Plasmodium falciparum document a remarkable increase in AZ potency when exposure is prolonged from one to two generations of intraerythrocytic growth, with AZ producing 50% inhibition of parasite growth at concentrations in the mid to low nanomolar range. In our culture-adapted lines, AZ displayed no synergy with chloroquine (CQ), amodiaquine, or artesunate. AZ activity was also unaffected by mutations in the pfcrt (P. falciparum chloroquine resistance transporter) or pfmdr1 (P. falciparum multidrug resistance-1) drug resistance loci, as determined using transgenic lines. We have selected mutant, AZ-resistant 7G8 and Dd2 parasite lines. In the AZ-resistant 7G8 line, the bacterial-like apicoplast large subunit ribosomal RNA harbored a U438C mutation in domain I. Both AZ-resistant lines revealed a G76V mutation in a conserved region of the apicoplast-encoded P. falciparum ribosomal protein L4 (PfRpl4). This protein is predicted to associate with the nuclear genome-encoded P. falciparum ribosomal protein L22 (PfRpl22) and the large subunit rRNA to form the 50 S ribosome polypeptide exit tunnel that can be occupied by AZ. The PfRpl22 sequence remained unchanged. Molecular modeling of mutant PfRpl4 with AZ suggests an altered orientation of the L75 side chain that could preclude AZ binding. These data imply that AZ acts on the apicoplast bacterial-like translation machinery and identify Pfrpl4 as a potential marker of resistance.
|
Antimalarial activity as 3rd generation ring-stage chloroquine-sensitive Plasmodium falciparum 3D7 after 48 hrs dose then 48 hrs drug-free
|
Plasmodium falciparum 3D7
|
52.7
nM
|
|
Journal : Antimicrob. Agents Chemother.
Title : Multiple antibiotics exert delayed effects against the Plasmodium falciparum apicoplast.
Year : 2007
Volume : 51
Issue : 10
First Page : 3485
Last Page : 3490
Authors : Dahl EL, Rosenthal PJ.
Abstract : Several classes of antibiotics exert antimalarial activity. The mechanisms of action of antibiotics against malaria parasites have been unclear, and prior studies have led to conflicting results, in part because they studied antibiotics at suprapharmacological concentrations. We examined the antimalarial effects of azithromycin, ciprofloxacin, clindamycin, doxycycline, and rifampin against chloroquine-resistant (W2) and chloroquine-sensitive (3D7) Plasmodium falciparum strains. At clinically relevant concentrations, rifampin killed parasites quickly, preventing them from initiating cell division. In contrast, pharmacological concentrations of azithromycin, ciprofloxacin, clindamycin, and doxycycline were relatively inactive against parasites initially but exerted a delayed death effect, in which the progeny of treated parasites failed to complete erythrocytic development. The drugs that caused delayed death did not alter the distribution of apicoplasts into developing progeny. However, the apicoplasts inherited by the progeny of treated parasites were abnormal. The loss of apicoplast function became apparent as the progeny of antibiotic-treated parasites initiated cell division, with the failure of schizonts to fully mature or for erythrocyte rupture to take place. These findings explain the slow antimalarial action of multiple antibiotics.
|
Antimalarial activity as 3rd generation ring-stage chloroquine-resistant Plasmodium falciparum W2 after 48 hrs dose then 48 hrs drug-free
|
Plasmodium falciparum
|
31.0
nM
|
|
Journal : Antimicrob. Agents Chemother.
Title : Multiple antibiotics exert delayed effects against the Plasmodium falciparum apicoplast.
Year : 2007
Volume : 51
Issue : 10
First Page : 3485
Last Page : 3490
Authors : Dahl EL, Rosenthal PJ.
Abstract : Several classes of antibiotics exert antimalarial activity. The mechanisms of action of antibiotics against malaria parasites have been unclear, and prior studies have led to conflicting results, in part because they studied antibiotics at suprapharmacological concentrations. We examined the antimalarial effects of azithromycin, ciprofloxacin, clindamycin, doxycycline, and rifampin against chloroquine-resistant (W2) and chloroquine-sensitive (3D7) Plasmodium falciparum strains. At clinically relevant concentrations, rifampin killed parasites quickly, preventing them from initiating cell division. In contrast, pharmacological concentrations of azithromycin, ciprofloxacin, clindamycin, and doxycycline were relatively inactive against parasites initially but exerted a delayed death effect, in which the progeny of treated parasites failed to complete erythrocytic development. The drugs that caused delayed death did not alter the distribution of apicoplasts into developing progeny. However, the apicoplasts inherited by the progeny of treated parasites were abnormal. The loss of apicoplast function became apparent as the progeny of antibiotic-treated parasites initiated cell division, with the failure of schizonts to fully mature or for erythrocyte rupture to take place. These findings explain the slow antimalarial action of multiple antibiotics.
|
Inhibition of quorum sensing-regulated elastase production in Pseudomonas aeruginosa NH57388A mucoid isolate harboring GFP-fused avian sarcoma virus lasB gene assessed as enzyme activity per cell at 2 ug/mL after 24 hrs relative to control
|
Pseudomonas aeruginosa
|
77.0
%
|
|
Journal : Antimicrob. Agents Chemother.
Title : Azithromycin blocks quorum sensing and alginate polymer formation and increases the sensitivity to serum and stationary-growth-phase killing of Pseudomonas aeruginosa and attenuates chronic P. aeruginosa lung infection in Cftr(-/-) mice.
Year : 2007
Volume : 51
Issue : 10
First Page : 3677
Last Page : 3687
Authors : Hoffmann N, Lee B, Hentzer M, Rasmussen TB, Song Z, Johansen HK, Givskov M, Høiby N.
Abstract : The consequences of O-acetylated alginate-producing Pseudomonas aeruginosa biofilms in the lungs of chronically infected cystic fibrosis (CF) patients are tolerance to both antibiotic treatments and effects on the innate and the adaptive defense mechanisms. In clinical trials, azithromycin (AZM) has been shown to improve the lung function of CF patients. The present study was conducted in accordance with previous in vitro studies suggesting that the effect of AZM may be the inhibition of alginate production, blockage of quorum sensing (QS), and increased sensitivity to hydrogen peroxide and the complement system. Moreover, we show that AZM may affect the polymerization of P. aeruginosa alginate by the incomplete precipitation of polymerized alginate and high levels of readily dialyzable uronic acids. In addition, we find that mucoid bacteria in the stationary growth phase became sensitive to AZM, whereas cells in the exponential phase did not. Interestingly, AZM-treated P. aeruginosa lasI mutants appeared to be particularly resistant to serum, whereas bacteria with a functional QS system did not. We show in a CF mouse model of chronic P. aeruginosa lung infection that AZM treatment results in the suppression of QS-regulated virulence factors, significantly improves the clearance of P. aeruginosa alginate biofilms, and reduces the severity of the lung pathology compared to that in control mice. We conclude that AZM attenuates the virulence of P. aeruginosa, impairs its ability to form fully polymerized alginate biofilms, and increases its sensitivity to complement and stationary-phase killing, which may explain the clinical efficacy of AZM.
|
Inhibition of quorum sensing-regulated elastase production in Pseudomonas aeruginosa NH57388A mucoid isolate harboring GFP-fused avian sarcoma virus lasB gene assessed as enzyme activity per cell at 4 ug/mL after 24 hrs relative to control
|
Pseudomonas aeruginosa
|
45.0
%
|
|
Journal : Antimicrob. Agents Chemother.
Title : Azithromycin blocks quorum sensing and alginate polymer formation and increases the sensitivity to serum and stationary-growth-phase killing of Pseudomonas aeruginosa and attenuates chronic P. aeruginosa lung infection in Cftr(-/-) mice.
Year : 2007
Volume : 51
Issue : 10
First Page : 3677
Last Page : 3687
Authors : Hoffmann N, Lee B, Hentzer M, Rasmussen TB, Song Z, Johansen HK, Givskov M, Høiby N.
Abstract : The consequences of O-acetylated alginate-producing Pseudomonas aeruginosa biofilms in the lungs of chronically infected cystic fibrosis (CF) patients are tolerance to both antibiotic treatments and effects on the innate and the adaptive defense mechanisms. In clinical trials, azithromycin (AZM) has been shown to improve the lung function of CF patients. The present study was conducted in accordance with previous in vitro studies suggesting that the effect of AZM may be the inhibition of alginate production, blockage of quorum sensing (QS), and increased sensitivity to hydrogen peroxide and the complement system. Moreover, we show that AZM may affect the polymerization of P. aeruginosa alginate by the incomplete precipitation of polymerized alginate and high levels of readily dialyzable uronic acids. In addition, we find that mucoid bacteria in the stationary growth phase became sensitive to AZM, whereas cells in the exponential phase did not. Interestingly, AZM-treated P. aeruginosa lasI mutants appeared to be particularly resistant to serum, whereas bacteria with a functional QS system did not. We show in a CF mouse model of chronic P. aeruginosa lung infection that AZM treatment results in the suppression of QS-regulated virulence factors, significantly improves the clearance of P. aeruginosa alginate biofilms, and reduces the severity of the lung pathology compared to that in control mice. We conclude that AZM attenuates the virulence of P. aeruginosa, impairs its ability to form fully polymerized alginate biofilms, and increases its sensitivity to complement and stationary-phase killing, which may explain the clinical efficacy of AZM.
|
Inhibition of quorum sensing-regulated elastase production in Pseudomonas aeruginosa NH57388A mucoid isolate harboring GFP-fused avian sarcoma virus lasB gene assessed as enzyme activity per cell at 8 ug/mL after 24 hrs relative to control
|
Pseudomonas aeruginosa
|
51.0
%
|
|
Journal : Antimicrob. Agents Chemother.
Title : Azithromycin blocks quorum sensing and alginate polymer formation and increases the sensitivity to serum and stationary-growth-phase killing of Pseudomonas aeruginosa and attenuates chronic P. aeruginosa lung infection in Cftr(-/-) mice.
Year : 2007
Volume : 51
Issue : 10
First Page : 3677
Last Page : 3687
Authors : Hoffmann N, Lee B, Hentzer M, Rasmussen TB, Song Z, Johansen HK, Givskov M, Høiby N.
Abstract : The consequences of O-acetylated alginate-producing Pseudomonas aeruginosa biofilms in the lungs of chronically infected cystic fibrosis (CF) patients are tolerance to both antibiotic treatments and effects on the innate and the adaptive defense mechanisms. In clinical trials, azithromycin (AZM) has been shown to improve the lung function of CF patients. The present study was conducted in accordance with previous in vitro studies suggesting that the effect of AZM may be the inhibition of alginate production, blockage of quorum sensing (QS), and increased sensitivity to hydrogen peroxide and the complement system. Moreover, we show that AZM may affect the polymerization of P. aeruginosa alginate by the incomplete precipitation of polymerized alginate and high levels of readily dialyzable uronic acids. In addition, we find that mucoid bacteria in the stationary growth phase became sensitive to AZM, whereas cells in the exponential phase did not. Interestingly, AZM-treated P. aeruginosa lasI mutants appeared to be particularly resistant to serum, whereas bacteria with a functional QS system did not. We show in a CF mouse model of chronic P. aeruginosa lung infection that AZM treatment results in the suppression of QS-regulated virulence factors, significantly improves the clearance of P. aeruginosa alginate biofilms, and reduces the severity of the lung pathology compared to that in control mice. We conclude that AZM attenuates the virulence of P. aeruginosa, impairs its ability to form fully polymerized alginate biofilms, and increases its sensitivity to complement and stationary-phase killing, which may explain the clinical efficacy of AZM.
|
Inhibition of quorum sensing-regulated chitinase production in Pseudomonas aeruginosa NH57388A mucoid isolate harboring GFP-fused avian sarcoma virus lasB gene assessed as enzyme activity per cell at 2 ug/mL after 24 hrs relative to control
|
Pseudomonas aeruginosa
|
66.0
%
|
|
Journal : Antimicrob. Agents Chemother.
Title : Azithromycin blocks quorum sensing and alginate polymer formation and increases the sensitivity to serum and stationary-growth-phase killing of Pseudomonas aeruginosa and attenuates chronic P. aeruginosa lung infection in Cftr(-/-) mice.
Year : 2007
Volume : 51
Issue : 10
First Page : 3677
Last Page : 3687
Authors : Hoffmann N, Lee B, Hentzer M, Rasmussen TB, Song Z, Johansen HK, Givskov M, Høiby N.
Abstract : The consequences of O-acetylated alginate-producing Pseudomonas aeruginosa biofilms in the lungs of chronically infected cystic fibrosis (CF) patients are tolerance to both antibiotic treatments and effects on the innate and the adaptive defense mechanisms. In clinical trials, azithromycin (AZM) has been shown to improve the lung function of CF patients. The present study was conducted in accordance with previous in vitro studies suggesting that the effect of AZM may be the inhibition of alginate production, blockage of quorum sensing (QS), and increased sensitivity to hydrogen peroxide and the complement system. Moreover, we show that AZM may affect the polymerization of P. aeruginosa alginate by the incomplete precipitation of polymerized alginate and high levels of readily dialyzable uronic acids. In addition, we find that mucoid bacteria in the stationary growth phase became sensitive to AZM, whereas cells in the exponential phase did not. Interestingly, AZM-treated P. aeruginosa lasI mutants appeared to be particularly resistant to serum, whereas bacteria with a functional QS system did not. We show in a CF mouse model of chronic P. aeruginosa lung infection that AZM treatment results in the suppression of QS-regulated virulence factors, significantly improves the clearance of P. aeruginosa alginate biofilms, and reduces the severity of the lung pathology compared to that in control mice. We conclude that AZM attenuates the virulence of P. aeruginosa, impairs its ability to form fully polymerized alginate biofilms, and increases its sensitivity to complement and stationary-phase killing, which may explain the clinical efficacy of AZM.
|
Inhibition of quorum sensing-regulated chitinase production in Pseudomonas aeruginosa NH57388A mucoid isolate harboring GFP-fused avian sarcoma virus lasB gene assessed as enzyme activity per cell at 4 ug/mL after 24 hrs relative to control
|
Pseudomonas aeruginosa
|
15.0
%
|
|
Journal : Antimicrob. Agents Chemother.
Title : Azithromycin blocks quorum sensing and alginate polymer formation and increases the sensitivity to serum and stationary-growth-phase killing of Pseudomonas aeruginosa and attenuates chronic P. aeruginosa lung infection in Cftr(-/-) mice.
Year : 2007
Volume : 51
Issue : 10
First Page : 3677
Last Page : 3687
Authors : Hoffmann N, Lee B, Hentzer M, Rasmussen TB, Song Z, Johansen HK, Givskov M, Høiby N.
Abstract : The consequences of O-acetylated alginate-producing Pseudomonas aeruginosa biofilms in the lungs of chronically infected cystic fibrosis (CF) patients are tolerance to both antibiotic treatments and effects on the innate and the adaptive defense mechanisms. In clinical trials, azithromycin (AZM) has been shown to improve the lung function of CF patients. The present study was conducted in accordance with previous in vitro studies suggesting that the effect of AZM may be the inhibition of alginate production, blockage of quorum sensing (QS), and increased sensitivity to hydrogen peroxide and the complement system. Moreover, we show that AZM may affect the polymerization of P. aeruginosa alginate by the incomplete precipitation of polymerized alginate and high levels of readily dialyzable uronic acids. In addition, we find that mucoid bacteria in the stationary growth phase became sensitive to AZM, whereas cells in the exponential phase did not. Interestingly, AZM-treated P. aeruginosa lasI mutants appeared to be particularly resistant to serum, whereas bacteria with a functional QS system did not. We show in a CF mouse model of chronic P. aeruginosa lung infection that AZM treatment results in the suppression of QS-regulated virulence factors, significantly improves the clearance of P. aeruginosa alginate biofilms, and reduces the severity of the lung pathology compared to that in control mice. We conclude that AZM attenuates the virulence of P. aeruginosa, impairs its ability to form fully polymerized alginate biofilms, and increases its sensitivity to complement and stationary-phase killing, which may explain the clinical efficacy of AZM.
|
Inhibition of quorum sensing-regulated chitinase production in Pseudomonas aeruginosa NH57388A mucoid isolate harboring GFP-fused avian sarcoma virus lasB gene assessed as enzyme activity per cell at 8 ug/mL after 24 hrs relative to control
|
Pseudomonas aeruginosa
|
10.0
%
|
|
Journal : Antimicrob. Agents Chemother.
Title : Azithromycin blocks quorum sensing and alginate polymer formation and increases the sensitivity to serum and stationary-growth-phase killing of Pseudomonas aeruginosa and attenuates chronic P. aeruginosa lung infection in Cftr(-/-) mice.
Year : 2007
Volume : 51
Issue : 10
First Page : 3677
Last Page : 3687
Authors : Hoffmann N, Lee B, Hentzer M, Rasmussen TB, Song Z, Johansen HK, Givskov M, Høiby N.
Abstract : The consequences of O-acetylated alginate-producing Pseudomonas aeruginosa biofilms in the lungs of chronically infected cystic fibrosis (CF) patients are tolerance to both antibiotic treatments and effects on the innate and the adaptive defense mechanisms. In clinical trials, azithromycin (AZM) has been shown to improve the lung function of CF patients. The present study was conducted in accordance with previous in vitro studies suggesting that the effect of AZM may be the inhibition of alginate production, blockage of quorum sensing (QS), and increased sensitivity to hydrogen peroxide and the complement system. Moreover, we show that AZM may affect the polymerization of P. aeruginosa alginate by the incomplete precipitation of polymerized alginate and high levels of readily dialyzable uronic acids. In addition, we find that mucoid bacteria in the stationary growth phase became sensitive to AZM, whereas cells in the exponential phase did not. Interestingly, AZM-treated P. aeruginosa lasI mutants appeared to be particularly resistant to serum, whereas bacteria with a functional QS system did not. We show in a CF mouse model of chronic P. aeruginosa lung infection that AZM treatment results in the suppression of QS-regulated virulence factors, significantly improves the clearance of P. aeruginosa alginate biofilms, and reduces the severity of the lung pathology compared to that in control mice. We conclude that AZM attenuates the virulence of P. aeruginosa, impairs its ability to form fully polymerized alginate biofilms, and increases its sensitivity to complement and stationary-phase killing, which may explain the clinical efficacy of AZM.
|
Inhibition of quorum sensing-regulated pyocyanin production in Pseudomonas aeruginosa NH57388A mucoid isolate harboring GFP-fused avian sarcoma virus lasB gene assessed as enzyme activity per cell at 2 ug/mL after 24 hrs relative to control
|
Pseudomonas aeruginosa
|
43.0
%
|
|
Journal : Antimicrob. Agents Chemother.
Title : Azithromycin blocks quorum sensing and alginate polymer formation and increases the sensitivity to serum and stationary-growth-phase killing of Pseudomonas aeruginosa and attenuates chronic P. aeruginosa lung infection in Cftr(-/-) mice.
Year : 2007
Volume : 51
Issue : 10
First Page : 3677
Last Page : 3687
Authors : Hoffmann N, Lee B, Hentzer M, Rasmussen TB, Song Z, Johansen HK, Givskov M, Høiby N.
Abstract : The consequences of O-acetylated alginate-producing Pseudomonas aeruginosa biofilms in the lungs of chronically infected cystic fibrosis (CF) patients are tolerance to both antibiotic treatments and effects on the innate and the adaptive defense mechanisms. In clinical trials, azithromycin (AZM) has been shown to improve the lung function of CF patients. The present study was conducted in accordance with previous in vitro studies suggesting that the effect of AZM may be the inhibition of alginate production, blockage of quorum sensing (QS), and increased sensitivity to hydrogen peroxide and the complement system. Moreover, we show that AZM may affect the polymerization of P. aeruginosa alginate by the incomplete precipitation of polymerized alginate and high levels of readily dialyzable uronic acids. In addition, we find that mucoid bacteria in the stationary growth phase became sensitive to AZM, whereas cells in the exponential phase did not. Interestingly, AZM-treated P. aeruginosa lasI mutants appeared to be particularly resistant to serum, whereas bacteria with a functional QS system did not. We show in a CF mouse model of chronic P. aeruginosa lung infection that AZM treatment results in the suppression of QS-regulated virulence factors, significantly improves the clearance of P. aeruginosa alginate biofilms, and reduces the severity of the lung pathology compared to that in control mice. We conclude that AZM attenuates the virulence of P. aeruginosa, impairs its ability to form fully polymerized alginate biofilms, and increases its sensitivity to complement and stationary-phase killing, which may explain the clinical efficacy of AZM.
|
Inhibition of quorum sensing-regulated pyocyanin production in Pseudomonas aeruginosa NH57388A mucoid isolate harboring GFP-fused avian sarcoma virus lasB gene assessed as enzyme activity per cell at 4 ug/mL after 24 hrs relative to control
|
Pseudomonas aeruginosa
|
32.0
%
|
|
Journal : Antimicrob. Agents Chemother.
Title : Azithromycin blocks quorum sensing and alginate polymer formation and increases the sensitivity to serum and stationary-growth-phase killing of Pseudomonas aeruginosa and attenuates chronic P. aeruginosa lung infection in Cftr(-/-) mice.
Year : 2007
Volume : 51
Issue : 10
First Page : 3677
Last Page : 3687
Authors : Hoffmann N, Lee B, Hentzer M, Rasmussen TB, Song Z, Johansen HK, Givskov M, Høiby N.
Abstract : The consequences of O-acetylated alginate-producing Pseudomonas aeruginosa biofilms in the lungs of chronically infected cystic fibrosis (CF) patients are tolerance to both antibiotic treatments and effects on the innate and the adaptive defense mechanisms. In clinical trials, azithromycin (AZM) has been shown to improve the lung function of CF patients. The present study was conducted in accordance with previous in vitro studies suggesting that the effect of AZM may be the inhibition of alginate production, blockage of quorum sensing (QS), and increased sensitivity to hydrogen peroxide and the complement system. Moreover, we show that AZM may affect the polymerization of P. aeruginosa alginate by the incomplete precipitation of polymerized alginate and high levels of readily dialyzable uronic acids. In addition, we find that mucoid bacteria in the stationary growth phase became sensitive to AZM, whereas cells in the exponential phase did not. Interestingly, AZM-treated P. aeruginosa lasI mutants appeared to be particularly resistant to serum, whereas bacteria with a functional QS system did not. We show in a CF mouse model of chronic P. aeruginosa lung infection that AZM treatment results in the suppression of QS-regulated virulence factors, significantly improves the clearance of P. aeruginosa alginate biofilms, and reduces the severity of the lung pathology compared to that in control mice. We conclude that AZM attenuates the virulence of P. aeruginosa, impairs its ability to form fully polymerized alginate biofilms, and increases its sensitivity to complement and stationary-phase killing, which may explain the clinical efficacy of AZM.
|
Inhibition of quorum sensing-regulated pyocyanin production in Pseudomonas aeruginosa NH57388A mucoid isolate harboring GFP-fused avian sarcoma virus lasB gene assessed as enzyme activity per cell at 8 ug/mL after 24 hrs relative to control
|
Pseudomonas aeruginosa
|
16.0
%
|
|
Journal : Antimicrob. Agents Chemother.
Title : Azithromycin blocks quorum sensing and alginate polymer formation and increases the sensitivity to serum and stationary-growth-phase killing of Pseudomonas aeruginosa and attenuates chronic P. aeruginosa lung infection in Cftr(-/-) mice.
Year : 2007
Volume : 51
Issue : 10
First Page : 3677
Last Page : 3687
Authors : Hoffmann N, Lee B, Hentzer M, Rasmussen TB, Song Z, Johansen HK, Givskov M, Høiby N.
Abstract : The consequences of O-acetylated alginate-producing Pseudomonas aeruginosa biofilms in the lungs of chronically infected cystic fibrosis (CF) patients are tolerance to both antibiotic treatments and effects on the innate and the adaptive defense mechanisms. In clinical trials, azithromycin (AZM) has been shown to improve the lung function of CF patients. The present study was conducted in accordance with previous in vitro studies suggesting that the effect of AZM may be the inhibition of alginate production, blockage of quorum sensing (QS), and increased sensitivity to hydrogen peroxide and the complement system. Moreover, we show that AZM may affect the polymerization of P. aeruginosa alginate by the incomplete precipitation of polymerized alginate and high levels of readily dialyzable uronic acids. In addition, we find that mucoid bacteria in the stationary growth phase became sensitive to AZM, whereas cells in the exponential phase did not. Interestingly, AZM-treated P. aeruginosa lasI mutants appeared to be particularly resistant to serum, whereas bacteria with a functional QS system did not. We show in a CF mouse model of chronic P. aeruginosa lung infection that AZM treatment results in the suppression of QS-regulated virulence factors, significantly improves the clearance of P. aeruginosa alginate biofilms, and reduces the severity of the lung pathology compared to that in control mice. We conclude that AZM attenuates the virulence of P. aeruginosa, impairs its ability to form fully polymerized alginate biofilms, and increases its sensitivity to complement and stationary-phase killing, which may explain the clinical efficacy of AZM.
|
Inhibition of quorum sensing-regulated alginate production in Pseudomonas aeruginosa NH57388A mucoid isolate harboring GFP-fused avian sarcoma virus lasB gene assessed as enzyme activity per cell at 2 ug/mL after 24 hrs relative to control
|
Pseudomonas aeruginosa
|
63.0
%
|
|
Journal : Antimicrob. Agents Chemother.
Title : Azithromycin blocks quorum sensing and alginate polymer formation and increases the sensitivity to serum and stationary-growth-phase killing of Pseudomonas aeruginosa and attenuates chronic P. aeruginosa lung infection in Cftr(-/-) mice.
Year : 2007
Volume : 51
Issue : 10
First Page : 3677
Last Page : 3687
Authors : Hoffmann N, Lee B, Hentzer M, Rasmussen TB, Song Z, Johansen HK, Givskov M, Høiby N.
Abstract : The consequences of O-acetylated alginate-producing Pseudomonas aeruginosa biofilms in the lungs of chronically infected cystic fibrosis (CF) patients are tolerance to both antibiotic treatments and effects on the innate and the adaptive defense mechanisms. In clinical trials, azithromycin (AZM) has been shown to improve the lung function of CF patients. The present study was conducted in accordance with previous in vitro studies suggesting that the effect of AZM may be the inhibition of alginate production, blockage of quorum sensing (QS), and increased sensitivity to hydrogen peroxide and the complement system. Moreover, we show that AZM may affect the polymerization of P. aeruginosa alginate by the incomplete precipitation of polymerized alginate and high levels of readily dialyzable uronic acids. In addition, we find that mucoid bacteria in the stationary growth phase became sensitive to AZM, whereas cells in the exponential phase did not. Interestingly, AZM-treated P. aeruginosa lasI mutants appeared to be particularly resistant to serum, whereas bacteria with a functional QS system did not. We show in a CF mouse model of chronic P. aeruginosa lung infection that AZM treatment results in the suppression of QS-regulated virulence factors, significantly improves the clearance of P. aeruginosa alginate biofilms, and reduces the severity of the lung pathology compared to that in control mice. We conclude that AZM attenuates the virulence of P. aeruginosa, impairs its ability to form fully polymerized alginate biofilms, and increases its sensitivity to complement and stationary-phase killing, which may explain the clinical efficacy of AZM.
|
Inhibition of quorum sensing-regulated alginate production in Pseudomonas aeruginosa NH57388A mucoid isolate harboring GFP-fused avian sarcoma virus lasB gene assessed as enzyme activity per cell at 4 ug/mL after 24 hrs relative to control
|
Pseudomonas aeruginosa
|
56.0
%
|
|
Journal : Antimicrob. Agents Chemother.
Title : Azithromycin blocks quorum sensing and alginate polymer formation and increases the sensitivity to serum and stationary-growth-phase killing of Pseudomonas aeruginosa and attenuates chronic P. aeruginosa lung infection in Cftr(-/-) mice.
Year : 2007
Volume : 51
Issue : 10
First Page : 3677
Last Page : 3687
Authors : Hoffmann N, Lee B, Hentzer M, Rasmussen TB, Song Z, Johansen HK, Givskov M, Høiby N.
Abstract : The consequences of O-acetylated alginate-producing Pseudomonas aeruginosa biofilms in the lungs of chronically infected cystic fibrosis (CF) patients are tolerance to both antibiotic treatments and effects on the innate and the adaptive defense mechanisms. In clinical trials, azithromycin (AZM) has been shown to improve the lung function of CF patients. The present study was conducted in accordance with previous in vitro studies suggesting that the effect of AZM may be the inhibition of alginate production, blockage of quorum sensing (QS), and increased sensitivity to hydrogen peroxide and the complement system. Moreover, we show that AZM may affect the polymerization of P. aeruginosa alginate by the incomplete precipitation of polymerized alginate and high levels of readily dialyzable uronic acids. In addition, we find that mucoid bacteria in the stationary growth phase became sensitive to AZM, whereas cells in the exponential phase did not. Interestingly, AZM-treated P. aeruginosa lasI mutants appeared to be particularly resistant to serum, whereas bacteria with a functional QS system did not. We show in a CF mouse model of chronic P. aeruginosa lung infection that AZM treatment results in the suppression of QS-regulated virulence factors, significantly improves the clearance of P. aeruginosa alginate biofilms, and reduces the severity of the lung pathology compared to that in control mice. We conclude that AZM attenuates the virulence of P. aeruginosa, impairs its ability to form fully polymerized alginate biofilms, and increases its sensitivity to complement and stationary-phase killing, which may explain the clinical efficacy of AZM.
|
Inhibition of quorum sensing-regulated alginate production in Pseudomonas aeruginosa NH57388A mucoid isolate harboring GFP-fused avian sarcoma virus lasB gene assessed as enzyme activity per cell at 8 ug/mL after 24 hrs relative to control
|
Pseudomonas aeruginosa
|
52.0
%
|
|
Journal : Antimicrob. Agents Chemother.
Title : Azithromycin blocks quorum sensing and alginate polymer formation and increases the sensitivity to serum and stationary-growth-phase killing of Pseudomonas aeruginosa and attenuates chronic P. aeruginosa lung infection in Cftr(-/-) mice.
Year : 2007
Volume : 51
Issue : 10
First Page : 3677
Last Page : 3687
Authors : Hoffmann N, Lee B, Hentzer M, Rasmussen TB, Song Z, Johansen HK, Givskov M, Høiby N.
Abstract : The consequences of O-acetylated alginate-producing Pseudomonas aeruginosa biofilms in the lungs of chronically infected cystic fibrosis (CF) patients are tolerance to both antibiotic treatments and effects on the innate and the adaptive defense mechanisms. In clinical trials, azithromycin (AZM) has been shown to improve the lung function of CF patients. The present study was conducted in accordance with previous in vitro studies suggesting that the effect of AZM may be the inhibition of alginate production, blockage of quorum sensing (QS), and increased sensitivity to hydrogen peroxide and the complement system. Moreover, we show that AZM may affect the polymerization of P. aeruginosa alginate by the incomplete precipitation of polymerized alginate and high levels of readily dialyzable uronic acids. In addition, we find that mucoid bacteria in the stationary growth phase became sensitive to AZM, whereas cells in the exponential phase did not. Interestingly, AZM-treated P. aeruginosa lasI mutants appeared to be particularly resistant to serum, whereas bacteria with a functional QS system did not. We show in a CF mouse model of chronic P. aeruginosa lung infection that AZM treatment results in the suppression of QS-regulated virulence factors, significantly improves the clearance of P. aeruginosa alginate biofilms, and reduces the severity of the lung pathology compared to that in control mice. We conclude that AZM attenuates the virulence of P. aeruginosa, impairs its ability to form fully polymerized alginate biofilms, and increases its sensitivity to complement and stationary-phase killing, which may explain the clinical efficacy of AZM.
|
Antiplasmodial activity after 96 hrs against Plasmodium falciparum 3D7 as Malstat LDH activity
|
Plasmodium falciparum 3D7
|
940.0
nM
|
|
Journal : Antimicrob. Agents Chemother.
Title : Telithromycin and quinupristin-dalfopristin induce delayed death in Plasmodium falciparum.
Year : 2008
Volume : 52
Issue : 2
First Page : 774
Last Page : 777
Authors : Barthel D, Schlitzer M, Pradel G.
Abstract : Antibacterial agents are used in malaria therapy due to their effect on two prokaryote organelles, the mitochondrion and the apicoplast. We demonstrate here that the ribosome-blocking antibiotics telithromycin and quinupristin-dalfopristin, but not linezolid, inhibit the growth of Plasmodium falciparum. Both drugs induce delayed death in the parasite, suggesting that their effect involves the impairment of apicoplast translation processes.
|
Antiplasmodial activity after 120 hrs against Plasmodium falciparum 3D7 as Malstat LDH activity
|
Plasmodium falciparum 3D7
|
410.0
nM
|
|
Journal : Antimicrob. Agents Chemother.
Title : Telithromycin and quinupristin-dalfopristin induce delayed death in Plasmodium falciparum.
Year : 2008
Volume : 52
Issue : 2
First Page : 774
Last Page : 777
Authors : Barthel D, Schlitzer M, Pradel G.
Abstract : Antibacterial agents are used in malaria therapy due to their effect on two prokaryote organelles, the mitochondrion and the apicoplast. We demonstrate here that the ribosome-blocking antibiotics telithromycin and quinupristin-dalfopristin, but not linezolid, inhibit the growth of Plasmodium falciparum. Both drugs induce delayed death in the parasite, suggesting that their effect involves the impairment of apicoplast translation processes.
|
Inhibition of Escherichia coli ribosome
|
Escherichia coli
|
300.0
nM
|
|
Journal : Bioorg. Med. Chem.
Title : Free and bound state structures of 6-O-methyl homoerythromycins and epitope mapping of their interactions with ribosomes.
Year : 2009
Volume : 17
Issue : 16
First Page : 5857
Last Page : 5867
Authors : Novak P, Barber J, Cikos A, Arsic B, Plavec J, Lazarevski G, Tepes P, Kosutić-Hulita N.
Abstract : The solution and solid state conformations of several 6-O-methyl homoerythromycins 1-4 were studied using a combination of X-ray crystallography, NMR spectroscopy and molecular modelling calculations. In the solid state 1 was found to exist as the two independent molecules with similar structures termed 3-endo-folded-out. In solution a significant conformational flexibility was noticed especially in the C2 to C5 region. The compounds 1 and 2 unlike 14-membered macrolides adopted the 3-endo-folded-out conformation while 3 and 4 existed in the classical folded-out conformation. TrNOESY and STD experiments showed that 1 and 2 bound to the Escherichia coli ribosome while 3 and 4, lacking the cladinose sugar, did not exhibit binding activities, this being in accordance with biochemical data. The bound conformations were found to be very similar to the free ones, some small differences were observed and discussed. The STD experiments provided evidence on binding epitopes. The structural parts of 1 and 2 in close contact with ribosome were similar, however the degree of saturation transfer was higher for 2. The differences between tr-NOE data and STD enhancements in 1 and 2 arouse as a consequence of structural changes upon binding and a closer proximity of 2 to the ribosome surface. An understanding of the molecular mechanisms involved in the interaction of macrolides with ribosomes can help in developing strategies aiming at design of potential inhibitors.
|
Inhibition of MexAB-OprM efflux pump expression in Pseudomonas aeruginosa TNP090 mutant harboring las and rhl gene at 1 ug/ml by Cat-2,3-diO reporter gene assay relative to untreated control
|
Pseudomonas aeruginosa
|
37.0
%
|
|
Journal : Antimicrob. Agents Chemother.
Title : Macrolide antibiotic-mediated downregulation of MexAB-OprM efflux pump expression in Pseudomonas aeruginosa.
Year : 2008
Volume : 52
Issue : 11
First Page : 4141
Last Page : 4144
Authors : Sugimura M, Maseda H, Hanaki H, Nakae T.
Abstract : Macrolide antibiotics modulate the quorum-sensing system of Pseudomonas aeruginosa. We tested the effect of macrolide antibiotics on the cell density-dependent expression of the MexAB-OprM efflux pump and found that 1.0 mug/ml (MIC/6.25) of azithromycin suppressed the expression of MexAB-OprM by about 70%, with the result that the cells became two- to fourfold more susceptible to antibiotics such as aztreonam, tetracycline, carbenicillin, chloramphenicol, and novobiocin.
|
Inhibition of MexAB-OprM efflux pump expression in Pseudomonas aeruginosa TNP090 mutant harboring las and rhl gene at 0.5 ug/ml by Cat-2,3-diO reporter gene assay relative to untreated control
|
Pseudomonas aeruginosa
|
65.0
%
|
|
Journal : Antimicrob. Agents Chemother.
Title : Macrolide antibiotic-mediated downregulation of MexAB-OprM efflux pump expression in Pseudomonas aeruginosa.
Year : 2008
Volume : 52
Issue : 11
First Page : 4141
Last Page : 4144
Authors : Sugimura M, Maseda H, Hanaki H, Nakae T.
Abstract : Macrolide antibiotics modulate the quorum-sensing system of Pseudomonas aeruginosa. We tested the effect of macrolide antibiotics on the cell density-dependent expression of the MexAB-OprM efflux pump and found that 1.0 mug/ml (MIC/6.25) of azithromycin suppressed the expression of MexAB-OprM by about 70%, with the result that the cells became two- to fourfold more susceptible to antibiotics such as aztreonam, tetracycline, carbenicillin, chloramphenicol, and novobiocin.
|
Inhibition of MexAB-OprM efflux pump expression in Pseudomonas aeruginosa TNP090 mutant harboring las and rhl gene at 0.25 ug/ml by Cat-2,3-diO reporter gene assay relative to untreated control
|
Pseudomonas aeruginosa
|
78.0
%
|
|
Journal : Antimicrob. Agents Chemother.
Title : Macrolide antibiotic-mediated downregulation of MexAB-OprM efflux pump expression in Pseudomonas aeruginosa.
Year : 2008
Volume : 52
Issue : 11
First Page : 4141
Last Page : 4144
Authors : Sugimura M, Maseda H, Hanaki H, Nakae T.
Abstract : Macrolide antibiotics modulate the quorum-sensing system of Pseudomonas aeruginosa. We tested the effect of macrolide antibiotics on the cell density-dependent expression of the MexAB-OprM efflux pump and found that 1.0 mug/ml (MIC/6.25) of azithromycin suppressed the expression of MexAB-OprM by about 70%, with the result that the cells became two- to fourfold more susceptible to antibiotics such as aztreonam, tetracycline, carbenicillin, chloramphenicol, and novobiocin.
|
Inhibition of MexAB-OprM efflux pump expression in Pseudomonas aeruginosa TNP090 mutant harboring las and rhl gene at 0.125 ug/ml by Cat-2,3-diO reporter gene assay relative to untreated control
|
Pseudomonas aeruginosa
|
85.0
%
|
|
Journal : Antimicrob. Agents Chemother.
Title : Macrolide antibiotic-mediated downregulation of MexAB-OprM efflux pump expression in Pseudomonas aeruginosa.
Year : 2008
Volume : 52
Issue : 11
First Page : 4141
Last Page : 4144
Authors : Sugimura M, Maseda H, Hanaki H, Nakae T.
Abstract : Macrolide antibiotics modulate the quorum-sensing system of Pseudomonas aeruginosa. We tested the effect of macrolide antibiotics on the cell density-dependent expression of the MexAB-OprM efflux pump and found that 1.0 mug/ml (MIC/6.25) of azithromycin suppressed the expression of MexAB-OprM by about 70%, with the result that the cells became two- to fourfold more susceptible to antibiotics such as aztreonam, tetracycline, carbenicillin, chloramphenicol, and novobiocin.
|
Inhibition of MexAB-OprM efflux pump expression in las1 and rhl1 deficient Pseudomonas aeruginosa TNP093 at 1 ug/ml after 9 hrs by Cat-2,3-diO reporter gene assay
|
Pseudomonas aeruginosa
|
100.0
%
|
|
Journal : Antimicrob. Agents Chemother.
Title : Macrolide antibiotic-mediated downregulation of MexAB-OprM efflux pump expression in Pseudomonas aeruginosa.
Year : 2008
Volume : 52
Issue : 11
First Page : 4141
Last Page : 4144
Authors : Sugimura M, Maseda H, Hanaki H, Nakae T.
Abstract : Macrolide antibiotics modulate the quorum-sensing system of Pseudomonas aeruginosa. We tested the effect of macrolide antibiotics on the cell density-dependent expression of the MexAB-OprM efflux pump and found that 1.0 mug/ml (MIC/6.25) of azithromycin suppressed the expression of MexAB-OprM by about 70%, with the result that the cells became two- to fourfold more susceptible to antibiotics such as aztreonam, tetracycline, carbenicillin, chloramphenicol, and novobiocin.
|
Inhibition of MexAB-OprM efflux pump expression in rhl1 deficient Pseudomonas aeruginosa TNP092 at 1 ug/ml after 9 hrs by Cat-2,3-diO reporter gene assay
|
Pseudomonas aeruginosa
|
90.0
%
|
|
Journal : Antimicrob. Agents Chemother.
Title : Macrolide antibiotic-mediated downregulation of MexAB-OprM efflux pump expression in Pseudomonas aeruginosa.
Year : 2008
Volume : 52
Issue : 11
First Page : 4141
Last Page : 4144
Authors : Sugimura M, Maseda H, Hanaki H, Nakae T.
Abstract : Macrolide antibiotics modulate the quorum-sensing system of Pseudomonas aeruginosa. We tested the effect of macrolide antibiotics on the cell density-dependent expression of the MexAB-OprM efflux pump and found that 1.0 mug/ml (MIC/6.25) of azithromycin suppressed the expression of MexAB-OprM by about 70%, with the result that the cells became two- to fourfold more susceptible to antibiotics such as aztreonam, tetracycline, carbenicillin, chloramphenicol, and novobiocin.
|
Inhibition of MexAB-OprM efflux pump expression in las1 deficient Pseudomonas aeruginosa TNP091 at 1 ug/ml after 9 hrs by Cat-2,3-diO reporter gene assay
|
Pseudomonas aeruginosa
|
99.0
%
|
|
Journal : Antimicrob. Agents Chemother.
Title : Macrolide antibiotic-mediated downregulation of MexAB-OprM efflux pump expression in Pseudomonas aeruginosa.
Year : 2008
Volume : 52
Issue : 11
First Page : 4141
Last Page : 4144
Authors : Sugimura M, Maseda H, Hanaki H, Nakae T.
Abstract : Macrolide antibiotics modulate the quorum-sensing system of Pseudomonas aeruginosa. We tested the effect of macrolide antibiotics on the cell density-dependent expression of the MexAB-OprM efflux pump and found that 1.0 mug/ml (MIC/6.25) of azithromycin suppressed the expression of MexAB-OprM by about 70%, with the result that the cells became two- to fourfold more susceptible to antibiotics such as aztreonam, tetracycline, carbenicillin, chloramphenicol, and novobiocin.
|
Inhibition of MexAB-OprM efflux pump expression in Pseudomonas aeruginosa TNP090 mutant harboring las and rhl gene at 1 ug/ml after 11.5 hrs by Cat-2,3-diO reporter gene assay relative to untreated control
|
Pseudomonas aeruginosa
|
-63.0
%
|
|
Journal : Antimicrob. Agents Chemother.
Title : Macrolide antibiotic-mediated downregulation of MexAB-OprM efflux pump expression in Pseudomonas aeruginosa.
Year : 2008
Volume : 52
Issue : 11
First Page : 4141
Last Page : 4144
Authors : Sugimura M, Maseda H, Hanaki H, Nakae T.
Abstract : Macrolide antibiotics modulate the quorum-sensing system of Pseudomonas aeruginosa. We tested the effect of macrolide antibiotics on the cell density-dependent expression of the MexAB-OprM efflux pump and found that 1.0 mug/ml (MIC/6.25) of azithromycin suppressed the expression of MexAB-OprM by about 70%, with the result that the cells became two- to fourfold more susceptible to antibiotics such as aztreonam, tetracycline, carbenicillin, chloramphenicol, and novobiocin.
|
Inhibition of MexAB-OprM efflux pump expression in Pseudomonas aeruginosa TNP090 mutant harboring las and rhl gene at 1 ug/ml after 9.5 hrs by Cat-2,3-diO reporter gene assay relative to untreated control
|
Pseudomonas aeruginosa
|
-70.2
%
|
|
Journal : Antimicrob. Agents Chemother.
Title : Macrolide antibiotic-mediated downregulation of MexAB-OprM efflux pump expression in Pseudomonas aeruginosa.
Year : 2008
Volume : 52
Issue : 11
First Page : 4141
Last Page : 4144
Authors : Sugimura M, Maseda H, Hanaki H, Nakae T.
Abstract : Macrolide antibiotics modulate the quorum-sensing system of Pseudomonas aeruginosa. We tested the effect of macrolide antibiotics on the cell density-dependent expression of the MexAB-OprM efflux pump and found that 1.0 mug/ml (MIC/6.25) of azithromycin suppressed the expression of MexAB-OprM by about 70%, with the result that the cells became two- to fourfold more susceptible to antibiotics such as aztreonam, tetracycline, carbenicillin, chloramphenicol, and novobiocin.
|
Inhibition of MexAB-OprM efflux pump expression in Pseudomonas aeruginosa TNP090 mutant harboring las and rhl gene at 1 ug/ml after 7.5 hrs by Cat-2,3-diO reporter gene assay relative to untreated control
|
Pseudomonas aeruginosa
|
-73.0
%
|
|
Journal : Antimicrob. Agents Chemother.
Title : Macrolide antibiotic-mediated downregulation of MexAB-OprM efflux pump expression in Pseudomonas aeruginosa.
Year : 2008
Volume : 52
Issue : 11
First Page : 4141
Last Page : 4144
Authors : Sugimura M, Maseda H, Hanaki H, Nakae T.
Abstract : Macrolide antibiotics modulate the quorum-sensing system of Pseudomonas aeruginosa. We tested the effect of macrolide antibiotics on the cell density-dependent expression of the MexAB-OprM efflux pump and found that 1.0 mug/ml (MIC/6.25) of azithromycin suppressed the expression of MexAB-OprM by about 70%, with the result that the cells became two- to fourfold more susceptible to antibiotics such as aztreonam, tetracycline, carbenicillin, chloramphenicol, and novobiocin.
|
Inhibition of MexAB-OprM efflux pump expression in Pseudomonas aeruginosa TNP090 mutant harboring las and rhl gene at 1 ug/ml after 5.5 hrs by Cat-2,3-diO reporter gene assay relative to untreated control
|
Pseudomonas aeruginosa
|
-30.9
%
|
|
Journal : Antimicrob. Agents Chemother.
Title : Macrolide antibiotic-mediated downregulation of MexAB-OprM efflux pump expression in Pseudomonas aeruginosa.
Year : 2008
Volume : 52
Issue : 11
First Page : 4141
Last Page : 4144
Authors : Sugimura M, Maseda H, Hanaki H, Nakae T.
Abstract : Macrolide antibiotics modulate the quorum-sensing system of Pseudomonas aeruginosa. We tested the effect of macrolide antibiotics on the cell density-dependent expression of the MexAB-OprM efflux pump and found that 1.0 mug/ml (MIC/6.25) of azithromycin suppressed the expression of MexAB-OprM by about 70%, with the result that the cells became two- to fourfold more susceptible to antibiotics such as aztreonam, tetracycline, carbenicillin, chloramphenicol, and novobiocin.
|
Inhibition of MexAB-OprM efflux pump expression in Pseudomonas aeruginosa at 1.0 ug/ml
|
Pseudomonas aeruginosa
|
70.0
%
|
|
Journal : Antimicrob. Agents Chemother.
Title : Macrolide antibiotic-mediated downregulation of MexAB-OprM efflux pump expression in Pseudomonas aeruginosa.
Year : 2008
Volume : 52
Issue : 11
First Page : 4141
Last Page : 4144
Authors : Sugimura M, Maseda H, Hanaki H, Nakae T.
Abstract : Macrolide antibiotics modulate the quorum-sensing system of Pseudomonas aeruginosa. We tested the effect of macrolide antibiotics on the cell density-dependent expression of the MexAB-OprM efflux pump and found that 1.0 mug/ml (MIC/6.25) of azithromycin suppressed the expression of MexAB-OprM by about 70%, with the result that the cells became two- to fourfold more susceptible to antibiotics such as aztreonam, tetracycline, carbenicillin, chloramphenicol, and novobiocin.
|
PUBCHEM_BIOASSAY: Luminescence Microorganism-Based Dose Response HTS to Identify Compounds Cytotoxic to Streptococcus. (Class of assay: confirmatory) [Related pubchem assays: 1900 (Counter Screen), 1677 (Project Summary), 1902 (Retest at Dose), 1662 (Primary HTS)]
|
Streptococcus
|
66.0
nM
|
|
Title : PubChem BioAssay data set
|
PUBCHEM_BIOASSAY: Luminescence Microorganism-Based Dose Confirmation HTS to Identify Compounds Cytotoxic to SK(-)GAS Group A Streptococcus. (Class of assay: confirmatory) [Related pubchem assays: 1677 (Project Summary), 1662 (Primary HTS)]
|
Streptococcus
|
60.0
nM
|
|
Title : PubChem BioAssay data set
|
PUBCHEM_BIOASSAY: Luminescence Microorganism-Based Dose Confirmation HTS to Identify Inhibitors of Streptokinase Promotor Activity. (Class of assay: confirmatory) [Related pubchem assays: 1677 (Project Summary), 1662 (Primary HTS)]
|
Streptococcus pyogenes M1 GAS
|
60.0
nM
|
|
Title : PubChem BioAssay data set
|
Bactericidal activity against Streptococcus pyogenes VT 59 assessed as eradication of pre-formed biofilm at 50 times MIC after 24 hrs
|
Streptococcus pyogenes
|
20.0
%
|
|
Journal : Antimicrob. Agents Chemother.
Title : Effect of DNase and antibiotics on biofilm characteristics.
Year : 2009
Volume : 53
Issue : 3
First Page : 1204
Last Page : 1209
Authors : Tetz GV, Artemenko NK, Tetz VV.
Abstract : The role of extracellular DNA in the maintenance of biofilms formed by gram-positive and gram-negative bacteria was studied. This study evaluated all the bacterial strains that were tested for the presence of extracellular DNA with an average size of 30 kb in the matrix. Our results indicate changes in community biomass, architecture, morphology, and the numbers of CFU in the presence of DNase. This effect seems to be common to biofilms established by various unrelated gram-positive and gram-negative bacteria. The cleavage of extracellular DNA leads to the formation of an altered biofilm that permits the increased penetration of antibiotics. Thus, the addition of DNase enhances the effect of antibiotics, resulting in decreased biofilm biomass and numbers of CFU.
|
Bactericidal activity against Klebsiella pneumoniae VT 1367 assessed as eradication of pre-formed biofilm at 50 times MIC after 24 hrs
|
Klebsiella pneumoniae
|
20.0
%
|
|
Journal : Antimicrob. Agents Chemother.
Title : Effect of DNase and antibiotics on biofilm characteristics.
Year : 2009
Volume : 53
Issue : 3
First Page : 1204
Last Page : 1209
Authors : Tetz GV, Artemenko NK, Tetz VV.
Abstract : The role of extracellular DNA in the maintenance of biofilms formed by gram-positive and gram-negative bacteria was studied. This study evaluated all the bacterial strains that were tested for the presence of extracellular DNA with an average size of 30 kb in the matrix. Our results indicate changes in community biomass, architecture, morphology, and the numbers of CFU in the presence of DNase. This effect seems to be common to biofilms established by various unrelated gram-positive and gram-negative bacteria. The cleavage of extracellular DNA leads to the formation of an altered biofilm that permits the increased penetration of antibiotics. Thus, the addition of DNase enhances the effect of antibiotics, resulting in decreased biofilm biomass and numbers of CFU.
|
Bactericidal activity against Escherichia coli ATCC 25922 assessed as eradication of pre-formed biofilm at 50 times MIC after 24 hrs
|
Escherichia coli
|
20.0
%
|
|
Journal : Antimicrob. Agents Chemother.
Title : Effect of DNase and antibiotics on biofilm characteristics.
Year : 2009
Volume : 53
Issue : 3
First Page : 1204
Last Page : 1209
Authors : Tetz GV, Artemenko NK, Tetz VV.
Abstract : The role of extracellular DNA in the maintenance of biofilms formed by gram-positive and gram-negative bacteria was studied. This study evaluated all the bacterial strains that were tested for the presence of extracellular DNA with an average size of 30 kb in the matrix. Our results indicate changes in community biomass, architecture, morphology, and the numbers of CFU in the presence of DNase. This effect seems to be common to biofilms established by various unrelated gram-positive and gram-negative bacteria. The cleavage of extracellular DNA leads to the formation of an altered biofilm that permits the increased penetration of antibiotics. Thus, the addition of DNase enhances the effect of antibiotics, resulting in decreased biofilm biomass and numbers of CFU.
|
Bactericidal activity against Pseudomonas aeruginosa ATCC 27853 assessed as eradication of pre-formed biofilm at 50 times MIC after 24 hrs
|
Pseudomonas aeruginosa
|
20.0
%
|
|
Journal : Antimicrob. Agents Chemother.
Title : Effect of DNase and antibiotics on biofilm characteristics.
Year : 2009
Volume : 53
Issue : 3
First Page : 1204
Last Page : 1209
Authors : Tetz GV, Artemenko NK, Tetz VV.
Abstract : The role of extracellular DNA in the maintenance of biofilms formed by gram-positive and gram-negative bacteria was studied. This study evaluated all the bacterial strains that were tested for the presence of extracellular DNA with an average size of 30 kb in the matrix. Our results indicate changes in community biomass, architecture, morphology, and the numbers of CFU in the presence of DNase. This effect seems to be common to biofilms established by various unrelated gram-positive and gram-negative bacteria. The cleavage of extracellular DNA leads to the formation of an altered biofilm that permits the increased penetration of antibiotics. Thus, the addition of DNase enhances the effect of antibiotics, resulting in decreased biofilm biomass and numbers of CFU.
|
Antibacterial activity against methicillin-sensitive Staphylococcus aureus ATCC 25923 assessed as decrease of CFU after 24 hrs
|
Staphylococcus aureus
|
0.12
ug.mL-1
|
|
Journal : Antimicrob. Agents Chemother.
Title : Cellular accumulation and pharmacodynamic evaluation of the intracellular activity of CEM-101, a novel fluoroketolide, against Staphylococcus aureus, Listeria monocytogenes, and Legionella pneumophila in human THP-1 macrophages.
Year : 2009
Volume : 53
Issue : 9
First Page : 3734
Last Page : 3743
Authors : Lemaire S, Van Bambeke F, Tulkens PM.
Abstract : CEM-101 is a novel fluoroketolide with lower MICs than those of telithromycin and macrolides. Our aim was to assess the cellular accumulation and intracellular activity of CEM-101 using models developed for analyzing the pharmacokinetics and pharmacological properties of antibiotics against phagocytized bacteria. We used THP-1 macrophages and Staphylococcus aureus (ATCC 25923 [methicillin (meticillin) sensitive]), Listeria monocytogenes (strain EGD), and Legionella pneumophila (ATCC 33153). CEM-101 reached cellular-to-extracellular-concentration ratios of about 350 within 24 h (versus approximately 20, 30, and 160 for telithromycin, clarithromycin, and azithromycin, respectively). This intracellular accumulation was suppressed by incubation at a pH of < or = 6 and by monensin (proton ionophore) and was unaffected by verapamil (P-glycoprotein inhibitor; twofold accumulation increase for azithromycin) or gemfibrozil. While keeping with the general properties of the macrolide antibiotics in terms of maximal efficacy (Emax; approximately 1-log10-CFU decrease compared to the postphagocytosis inoculum after a 24-h incubation), CEM-101 showed significantly greater potency against phagocytized S. aureus than telithromycin, clarithromycin, and azithromycin (for which the 50% effective concentration [EC50] and static concentrations were about 3-, 6-, and 15-fold lower, respectively). CEM-101 was also about 50-fold and 100-fold more potent than azithromycin against phagocytized L. monocytogenes and L. pneumophila, respectively. These differences in EC50s and static concentrations between drugs were minimized when data were expressed as multiples of the MIC, demonstrating the critical role of intrinsic drug activity (MIC) in eliciting the antibacterial intracellular effects, whereas accumulation per se was unimportant. CEM-101 should show enhanced in vivo potency if used at doses similar to those of the comparators tested here.
|
Antibacterial activity against methicillin-sensitive Staphylococcus aureus ATCC 25923 infected in human THP1 cells assessed as decrease of CFU after 24 hrs
|
Staphylococcus aureus
|
0.024
ug.mL-1
|
|
Journal : Antimicrob. Agents Chemother.
Title : Cellular accumulation and pharmacodynamic evaluation of the intracellular activity of CEM-101, a novel fluoroketolide, against Staphylococcus aureus, Listeria monocytogenes, and Legionella pneumophila in human THP-1 macrophages.
Year : 2009
Volume : 53
Issue : 9
First Page : 3734
Last Page : 3743
Authors : Lemaire S, Van Bambeke F, Tulkens PM.
Abstract : CEM-101 is a novel fluoroketolide with lower MICs than those of telithromycin and macrolides. Our aim was to assess the cellular accumulation and intracellular activity of CEM-101 using models developed for analyzing the pharmacokinetics and pharmacological properties of antibiotics against phagocytized bacteria. We used THP-1 macrophages and Staphylococcus aureus (ATCC 25923 [methicillin (meticillin) sensitive]), Listeria monocytogenes (strain EGD), and Legionella pneumophila (ATCC 33153). CEM-101 reached cellular-to-extracellular-concentration ratios of about 350 within 24 h (versus approximately 20, 30, and 160 for telithromycin, clarithromycin, and azithromycin, respectively). This intracellular accumulation was suppressed by incubation at a pH of < or = 6 and by monensin (proton ionophore) and was unaffected by verapamil (P-glycoprotein inhibitor; twofold accumulation increase for azithromycin) or gemfibrozil. While keeping with the general properties of the macrolide antibiotics in terms of maximal efficacy (Emax; approximately 1-log10-CFU decrease compared to the postphagocytosis inoculum after a 24-h incubation), CEM-101 showed significantly greater potency against phagocytized S. aureus than telithromycin, clarithromycin, and azithromycin (for which the 50% effective concentration [EC50] and static concentrations were about 3-, 6-, and 15-fold lower, respectively). CEM-101 was also about 50-fold and 100-fold more potent than azithromycin against phagocytized L. monocytogenes and L. pneumophila, respectively. These differences in EC50s and static concentrations between drugs were minimized when data were expressed as multiples of the MIC, demonstrating the critical role of intrinsic drug activity (MIC) in eliciting the antibacterial intracellular effects, whereas accumulation per se was unimportant. CEM-101 should show enhanced in vivo potency if used at doses similar to those of the comparators tested here.
|
Antibacterial activity against methicillin-sensitive Listeria monocytogenes EGD assessed as decrease of CFU after 24 hrs
|
Listeria monocytogenes EGD-e
|
2.66
ug.mL-1
|
|
Journal : Antimicrob. Agents Chemother.
Title : Cellular accumulation and pharmacodynamic evaluation of the intracellular activity of CEM-101, a novel fluoroketolide, against Staphylococcus aureus, Listeria monocytogenes, and Legionella pneumophila in human THP-1 macrophages.
Year : 2009
Volume : 53
Issue : 9
First Page : 3734
Last Page : 3743
Authors : Lemaire S, Van Bambeke F, Tulkens PM.
Abstract : CEM-101 is a novel fluoroketolide with lower MICs than those of telithromycin and macrolides. Our aim was to assess the cellular accumulation and intracellular activity of CEM-101 using models developed for analyzing the pharmacokinetics and pharmacological properties of antibiotics against phagocytized bacteria. We used THP-1 macrophages and Staphylococcus aureus (ATCC 25923 [methicillin (meticillin) sensitive]), Listeria monocytogenes (strain EGD), and Legionella pneumophila (ATCC 33153). CEM-101 reached cellular-to-extracellular-concentration ratios of about 350 within 24 h (versus approximately 20, 30, and 160 for telithromycin, clarithromycin, and azithromycin, respectively). This intracellular accumulation was suppressed by incubation at a pH of < or = 6 and by monensin (proton ionophore) and was unaffected by verapamil (P-glycoprotein inhibitor; twofold accumulation increase for azithromycin) or gemfibrozil. While keeping with the general properties of the macrolide antibiotics in terms of maximal efficacy (Emax; approximately 1-log10-CFU decrease compared to the postphagocytosis inoculum after a 24-h incubation), CEM-101 showed significantly greater potency against phagocytized S. aureus than telithromycin, clarithromycin, and azithromycin (for which the 50% effective concentration [EC50] and static concentrations were about 3-, 6-, and 15-fold lower, respectively). CEM-101 was also about 50-fold and 100-fold more potent than azithromycin against phagocytized L. monocytogenes and L. pneumophila, respectively. These differences in EC50s and static concentrations between drugs were minimized when data were expressed as multiples of the MIC, demonstrating the critical role of intrinsic drug activity (MIC) in eliciting the antibacterial intracellular effects, whereas accumulation per se was unimportant. CEM-101 should show enhanced in vivo potency if used at doses similar to those of the comparators tested here.
|
Antibacterial activity against methicillin-sensitive Listeria monocytogenes EGD infected in human THP1 cells assessed as decrease of CFU after 24 hrs
|
Listeria monocytogenes EGD-e
|
2.86
ug.mL-1
|
|
Journal : Antimicrob. Agents Chemother.
Title : Cellular accumulation and pharmacodynamic evaluation of the intracellular activity of CEM-101, a novel fluoroketolide, against Staphylococcus aureus, Listeria monocytogenes, and Legionella pneumophila in human THP-1 macrophages.
Year : 2009
Volume : 53
Issue : 9
First Page : 3734
Last Page : 3743
Authors : Lemaire S, Van Bambeke F, Tulkens PM.
Abstract : CEM-101 is a novel fluoroketolide with lower MICs than those of telithromycin and macrolides. Our aim was to assess the cellular accumulation and intracellular activity of CEM-101 using models developed for analyzing the pharmacokinetics and pharmacological properties of antibiotics against phagocytized bacteria. We used THP-1 macrophages and Staphylococcus aureus (ATCC 25923 [methicillin (meticillin) sensitive]), Listeria monocytogenes (strain EGD), and Legionella pneumophila (ATCC 33153). CEM-101 reached cellular-to-extracellular-concentration ratios of about 350 within 24 h (versus approximately 20, 30, and 160 for telithromycin, clarithromycin, and azithromycin, respectively). This intracellular accumulation was suppressed by incubation at a pH of < or = 6 and by monensin (proton ionophore) and was unaffected by verapamil (P-glycoprotein inhibitor; twofold accumulation increase for azithromycin) or gemfibrozil. While keeping with the general properties of the macrolide antibiotics in terms of maximal efficacy (Emax; approximately 1-log10-CFU decrease compared to the postphagocytosis inoculum after a 24-h incubation), CEM-101 showed significantly greater potency against phagocytized S. aureus than telithromycin, clarithromycin, and azithromycin (for which the 50% effective concentration [EC50] and static concentrations were about 3-, 6-, and 15-fold lower, respectively). CEM-101 was also about 50-fold and 100-fold more potent than azithromycin against phagocytized L. monocytogenes and L. pneumophila, respectively. These differences in EC50s and static concentrations between drugs were minimized when data were expressed as multiples of the MIC, demonstrating the critical role of intrinsic drug activity (MIC) in eliciting the antibacterial intracellular effects, whereas accumulation per se was unimportant. CEM-101 should show enhanced in vivo potency if used at doses similar to those of the comparators tested here.
|
Inhibition of quorum sensing activity in Pseudomonas aeruginosa ATCC 27853 assessed as N-acylhomoserin lactones production at 5 ug/ml after 24 hrs by measuring beta-galactosidase activity by spectrophotometry
|
Pseudomonas aeruginosa
|
76.0
%
|
|
Journal : J. Nat. Prod.
Title : Bioactive sesqui- and diterpenoids from the Argentine liverwort Porella chilensis.
Year : 2011
Volume : 74
Issue : 4
First Page : 574
Last Page : 579
Authors : Gilabert M, Ramos AN, Schiavone MM, Arena ME, Bardón A.
Abstract : Four fusicoccane-type diterpenoids (1-4), including the new 1 and 2; four pinguisane-type sesquiterpenoids (5-8); and two aromadendrane-type sesquiterpenoids (9 and 10) were isolated from an Argentine collection of the endemic liverwort Porella chilensis. The biofilm formation of the human pathogen Pseudomonas aeruginosa was inhibited by compounds 3 (53 and 47%), 9 (45 and 41%), and 10 (48 and 37%) at 50 and 5 μg/mL, respectively. Compounds 3, 9, and 10 also produced a slight decrease in bacterial growth and interfere with the process of quorum sensing at the same doses.
|
Antiparasitic activity against yellow fluorescent protein expressing Toxoplasma gondii 2F-1 treated immediately after infection for 48 hrs followed by reinoculated into fresh HFF monolayers measured after 48 hrs
|
Toxoplasma gondii
|
600.0
nM
|
|
Journal : J. Med. Chem.
Title : Chemistry and biology of macrolide antiparasitic agents.
Year : 2011
Volume : 54
Issue : 8
First Page : 2792
Last Page : 2804
Authors : Lee Y, Choi JY, Fu H, Harvey C, Ravindran S, Roush WR, Boothroyd JC, Khosla C.
Abstract : Macrolide antibacterial agents inhibit parasite proliferation by targeting the apicoplast ribosome. Motivated by the long-term goal of identifying antiparasitic macrolides that lack antibacterial activity, we have systematically analyzed the structure-activity relationships among erythromycin analogues and have also investigated the mechanism of action of selected compounds. Two lead compounds, N-benzylazithromycin (11) and N-phenylpropylazithromycin (30), were identified with significantly higher antiparasitic activity and lower antibacterial activity than erythromycin or azithromycin. Molecular modeling based on the cocrystal structure of azithromycin bound to the bacterial ribosome suggested that a substituent at the N-9 position of desmethylazithromycin could improve selectivity because of species-specific interactions with the ribosomal L22 protein. Like other macrolides, these lead compounds display a strong "delayed death phenotype"; however, their early effects on T. gondii replication are more pronounced.
|
Antiparasitic activity against yellow fluorescent protein expressing Toxoplasma gondii 2F-1 treated 6 hrs after infection for 42 hrs followed by reinoculated into fresh HFF monolayers measured after 48 hrs
|
Toxoplasma gondii
|
600.0
nM
|
|
Journal : J. Med. Chem.
Title : Chemistry and biology of macrolide antiparasitic agents.
Year : 2011
Volume : 54
Issue : 8
First Page : 2792
Last Page : 2804
Authors : Lee Y, Choi JY, Fu H, Harvey C, Ravindran S, Roush WR, Boothroyd JC, Khosla C.
Abstract : Macrolide antibacterial agents inhibit parasite proliferation by targeting the apicoplast ribosome. Motivated by the long-term goal of identifying antiparasitic macrolides that lack antibacterial activity, we have systematically analyzed the structure-activity relationships among erythromycin analogues and have also investigated the mechanism of action of selected compounds. Two lead compounds, N-benzylazithromycin (11) and N-phenylpropylazithromycin (30), were identified with significantly higher antiparasitic activity and lower antibacterial activity than erythromycin or azithromycin. Molecular modeling based on the cocrystal structure of azithromycin bound to the bacterial ribosome suggested that a substituent at the N-9 position of desmethylazithromycin could improve selectivity because of species-specific interactions with the ribosomal L22 protein. Like other macrolides, these lead compounds display a strong "delayed death phenotype"; however, their early effects on T. gondii replication are more pronounced.
|
Antimalarial activity against Plasmodium falciparum after 68 hrs
|
Plasmodium falciparum
|
0.5
ug.mL-1
|
|
Journal : J. Med. Chem.
Title : Synthesis, structure-activity relationship, and antimalarial activity of ureas and thioureas of 15-membered azalides.
Year : 2011
Volume : 54
Issue : 10
First Page : 3595
Last Page : 3605
Authors : Bukvić Krajačić M, Perić M, Smith KS, Schönfeld ZI, Žiher D, Fajdetić A, Kujundžić N, Schönfeld W, Landek G, Padovan J, Jelić D, Ager A, Milhous WK, Ellis W, Spaventi R, Ohrt C.
Abstract : Azithromycin, a first member of the azalide family of macrolides, while having substantial antimalarial activity, failed as a single agent for malaria prophylaxis. In this paper we present the first analogue campaign to identify more potent compounds from this class. Ureas and thioureas of 15-membered azalides, N''-substituted 9a-(N'-carbamoyl-β-aminoethyl), 9a-(N'-thiocarbamoyl-β-aminoethyl), 9a-[N'-(β-cyanoethyl)-N'-(carbamoyl-β-aminoethyl)], 9a-[N'-(β-cyanoethyl)-N'-(thiocarbamoyl-β-aminoethyl)], 9a-{N'-[β-(ethoxycarbonyl)ethyl]-N'(carbamoyl-β-aminoethyl)}, and 9a-[N'-(β-amidoethyl)-N'-(carbamoyl-β-aminoethyl)] of 9-deoxo-9-dihydro-9a-aza-9a-homoerythromycin A, were synthesized and their biological properties evaluated. The results obtained indicate a substantial improvement of the in vitro activity against P. falciparum (up to 88 times over azithromycin), particularly for compounds containing both sugars on the macrocyclic ring and aromatic moiety on 9a-position. The improved in vitro activity was not confirmed in the mouse model, likely due to an increase in lipophilicity of these analogues leading to a higher volume of distribution. Overall, with increased in vitro activity, promising PK properties, and modest in vivo efficacy, this series of molecules represents a good starting platform for the design of novel antimalarial azalides.
|
Antiinflammatory activity in mouse splenocytes assessed as inhibition of LPS-induced IL-6 production at 50 uM preincubated for 2 hrs prior to LPS challenge by sandwich ELISA
|
Mus musculus
|
84.0
%
|
|
Journal : J. Med. Chem.
Title : N'-substituted-2'-O,3'-N-carbonimidoyl bridged macrolides: novel anti-inflammatory macrolides without antimicrobial activity.
Year : 2012
Volume : 55
Issue : 13
First Page : 6111
Last Page : 6123
Authors : Bosnar M, Kragol G, Koštrun S, Vujasinović I, Bošnjak B, Bencetić Mihaljević V, Marušić Ištuk Z, Kapić S, Hrvačić B, Brajša K, Tavčar B, Jelić D, Glojnarić I, Verbanac D, Culić O, Padovan J, Alihodžić S, Eraković Haber V, Spaventi R.
Abstract : Macrolide antibiotics, like erythromycin, clarithromycin, and azithromycin, possess anti-inflammatory properties. These properties are considered fundamental to the efficacy of these three macrolides in the treatment of chronic inflammatory diseases like diffuse panbronchiolitis and cystic fibrosis. However, long-term treatment with macrolide antibiotics presents a considerable risk for promotion of bacterial resistance. We have examined antibacterial and anti-inflammatory effects of a novel macrolide class: N'-substituted 2'-O,3'-N-carbonimidoyl bridged erythromycin-derived 14- and 15-membered macrolides. A small focused library was prepared, and compounds without antimicrobial activity, which inhibited IL-6 production, were selected. Data analysis led to a statistical model that could be used for the design of novel anti-inflammatory macrolides. The most promising compound from this library retained the anti-inflammatory activity observed with azithromycin in lipopolysaccharide-induced pulmonary neutrophilia in vivo. Importantly, this study strongly suggests that antimicrobial and anti-inflammatory activities of macrolides are independent and can be separated, which raises development plausibility of novel anti-inflammatory therapeutics.
|
Antiinflammatory activity in mouse splenocytes assessed as inhibition of LPS-induced IL-6 production in mouse splenocytes at 25 uM preincubated for 2 hrs prior to LPS challenge by sandwich ELISA
|
Mus musculus
|
74.0
%
|
|
Journal : J. Med. Chem.
Title : N'-substituted-2'-O,3'-N-carbonimidoyl bridged macrolides: novel anti-inflammatory macrolides without antimicrobial activity.
Year : 2012
Volume : 55
Issue : 13
First Page : 6111
Last Page : 6123
Authors : Bosnar M, Kragol G, Koštrun S, Vujasinović I, Bošnjak B, Bencetić Mihaljević V, Marušić Ištuk Z, Kapić S, Hrvačić B, Brajša K, Tavčar B, Jelić D, Glojnarić I, Verbanac D, Culić O, Padovan J, Alihodžić S, Eraković Haber V, Spaventi R.
Abstract : Macrolide antibiotics, like erythromycin, clarithromycin, and azithromycin, possess anti-inflammatory properties. These properties are considered fundamental to the efficacy of these three macrolides in the treatment of chronic inflammatory diseases like diffuse panbronchiolitis and cystic fibrosis. However, long-term treatment with macrolide antibiotics presents a considerable risk for promotion of bacterial resistance. We have examined antibacterial and anti-inflammatory effects of a novel macrolide class: N'-substituted 2'-O,3'-N-carbonimidoyl bridged erythromycin-derived 14- and 15-membered macrolides. A small focused library was prepared, and compounds without antimicrobial activity, which inhibited IL-6 production, were selected. Data analysis led to a statistical model that could be used for the design of novel anti-inflammatory macrolides. The most promising compound from this library retained the anti-inflammatory activity observed with azithromycin in lipopolysaccharide-induced pulmonary neutrophilia in vivo. Importantly, this study strongly suggests that antimicrobial and anti-inflammatory activities of macrolides are independent and can be separated, which raises development plausibility of novel anti-inflammatory therapeutics.
|
Antiinflammatory activity in mouse splenocytes assessed as inhibition of LPS-induced IL-6 production at 12 uM preincubated for 2 hrs prior to LPS challenge by sandwich ELISA
|
Mus musculus
|
61.0
%
|
|
Journal : J. Med. Chem.
Title : N'-substituted-2'-O,3'-N-carbonimidoyl bridged macrolides: novel anti-inflammatory macrolides without antimicrobial activity.
Year : 2012
Volume : 55
Issue : 13
First Page : 6111
Last Page : 6123
Authors : Bosnar M, Kragol G, Koštrun S, Vujasinović I, Bošnjak B, Bencetić Mihaljević V, Marušić Ištuk Z, Kapić S, Hrvačić B, Brajša K, Tavčar B, Jelić D, Glojnarić I, Verbanac D, Culić O, Padovan J, Alihodžić S, Eraković Haber V, Spaventi R.
Abstract : Macrolide antibiotics, like erythromycin, clarithromycin, and azithromycin, possess anti-inflammatory properties. These properties are considered fundamental to the efficacy of these three macrolides in the treatment of chronic inflammatory diseases like diffuse panbronchiolitis and cystic fibrosis. However, long-term treatment with macrolide antibiotics presents a considerable risk for promotion of bacterial resistance. We have examined antibacterial and anti-inflammatory effects of a novel macrolide class: N'-substituted 2'-O,3'-N-carbonimidoyl bridged erythromycin-derived 14- and 15-membered macrolides. A small focused library was prepared, and compounds without antimicrobial activity, which inhibited IL-6 production, were selected. Data analysis led to a statistical model that could be used for the design of novel anti-inflammatory macrolides. The most promising compound from this library retained the anti-inflammatory activity observed with azithromycin in lipopolysaccharide-induced pulmonary neutrophilia in vivo. Importantly, this study strongly suggests that antimicrobial and anti-inflammatory activities of macrolides are independent and can be separated, which raises development plausibility of novel anti-inflammatory therapeutics.
|
Inhibition of COX-2 (unknown origin) using arachidonic acid as substrate assessed as formation of prostanoid products at 500 uM preincubated for 10 mins prior to substrate addition measured after 2 mins by Ellman's method relative to control
|
Homo sapiens
|
99.0
%
|
|
Journal : J. Med. Chem.
Title : Experimental confirmation of new drug-target interactions predicted by Drug Profile Matching.
Year : 2013
Volume : 56
Issue : 21
First Page : 8377
Last Page : 8388
Authors : Végner L, Peragovics Á, Tombor L, Jelinek B, Czobor P, Bender A, Simon Z, Málnási-Csizmadia A.
Abstract : We recently introduced Drug Profile Matching (DPM), a novel affinity fingerprinting-based in silico drug repositioning approach. DPM is able to quantitatively predict the complete effect profiles of compounds via probability scores. In the present work, in order to investigate the predictive power of DPM, three effect categories, namely, angiotensin-converting enzyme inhibitor, cyclooxygenase inhibitor, and dopamine agent, were selected and predictions were verified by literature analysis as well as experimentally. A total of 72% of the newly predicted and tested dopaminergic compounds were confirmed by tests on D1 and D2 expressing cell cultures. 33% and 23% of the ACE and COX inhibitory predictions were confirmed by in vitro tests, respectively. Dose-dependent inhibition curves were measured for seven drugs, and their inhibitory constants (Ki) were determined. Our study overall demonstrates that DPM is an effective approach to reveal novel drug-target pairs that may result in repositioning these drugs.
|
Inhibition of COX-1 (unknown origin) using arachidonic acid as substrate assessed as formation of prostanoid products at 500 uM preincubated for 10 mins prior to substrate addition measured after 2 mins by Ellman's method relative to control
|
Homo sapiens
|
68.0
%
|
|
Journal : J. Med. Chem.
Title : Experimental confirmation of new drug-target interactions predicted by Drug Profile Matching.
Year : 2013
Volume : 56
Issue : 21
First Page : 8377
Last Page : 8388
Authors : Végner L, Peragovics Á, Tombor L, Jelinek B, Czobor P, Bender A, Simon Z, Málnási-Csizmadia A.
Abstract : We recently introduced Drug Profile Matching (DPM), a novel affinity fingerprinting-based in silico drug repositioning approach. DPM is able to quantitatively predict the complete effect profiles of compounds via probability scores. In the present work, in order to investigate the predictive power of DPM, three effect categories, namely, angiotensin-converting enzyme inhibitor, cyclooxygenase inhibitor, and dopamine agent, were selected and predictions were verified by literature analysis as well as experimentally. A total of 72% of the newly predicted and tested dopaminergic compounds were confirmed by tests on D1 and D2 expressing cell cultures. 33% and 23% of the ACE and COX inhibitory predictions were confirmed by in vitro tests, respectively. Dose-dependent inhibition curves were measured for seven drugs, and their inhibitory constants (Ki) were determined. Our study overall demonstrates that DPM is an effective approach to reveal novel drug-target pairs that may result in repositioning these drugs.
|
Inhibition of ribosome nascent peptide exit tunnel in Escherichia coli S30 extract assessed as inhibition of prokaryotic translation in presence of amino acids incubated for 20 mins by luciferase reporter gene assay
|
Escherichia coli
|
292.0
nM
|
|
Journal : Bioorg. Med. Chem.
Title : Exploiting translational stalling peptides in an effort to extend azithromycin interaction within the prokaryotic ribosome nascent peptide exit tunnel.
Year : 2015
Volume : 23
Issue : 16
First Page : 5198
Last Page : 5209
Authors : Washington AZ, Tapadar S, George A, Oyelere AK.
Abstract : The ribosome is the primary protein synthesis machine in the cell and is a target for treatment of a variety of diseases including bacterial infection and cancer. The ribosomal peptide exit tunnel, the route of egress for the nascent peptide, is an inviting site for drug design. Toward a rational engagement of the nascent peptide components for the design of small molecule inhibitors of ribosome function, we designed and disclosed herein a set of N-10 indole functionalized azithromycin analogs. The indole moiety of these compounds is designed to mimic the translation stalling interaction of SecM W155 side-chain with the prokaryotic (Escherichia coli) ribosome A751 residue. Many of these N-10 functionalized compounds have enhanced translation inhibition activities against E. coli ribosome relative to azithromycin while a subset inhibited the growth of representative susceptible bacteria strains to about the same extent as azithromycin. Moreover, the inclusion of bovine serum in the bacterial growth media enhanced the anti-bacterial potency of the N-10 functionalized azithromycin analogs by as high as 10-fold.
|
Antichlamydial activity against Chlamydia trachomatis serovar L2 infected in human HeLa 299 cells assessed as reduction in number of inclusion bodies measured after 44 to 48 hrs by DAPI staining-based HCS assay
|
Chlamydia trachomatis
|
727.0
nM
|
|
Journal : Eur J Med Chem
Title : Natural product inspired library synthesis - Identification of 2,3-diarylbenzofuran and 2,3-dihydrobenzofuran based inhibitors of Chlamydia trachomatis.
Year : 2018
Volume : 143
First Page : 1077
Last Page : 1089
Authors : Saleeb M, Mojica S, Eriksson AU, Andersson CD, Gylfe Å, Elofsson M.
Abstract : A natural product inspired library was synthesized based on 2,3-diarylbenzofuran and 2,3-diaryl-2,3-dihydrobenzofuran scaffolds. The library of forty-eight compounds was prepared by utilizing Pd-catalyzed one-pot multicomponent reactions and ruthenium-catalyzed intramolecular carbenoid C-H insertions. The compounds were evaluated for antibacterial activity in a panel of test systems including phenotypic, biochemical and image-based screening assays. We identified several potent inhibitors that block intracellular replication of pathogenic Chlamydia trachomatis with IC50 ≤ 3 μM. These new C. trachomatis inhibitors can serve as starting points for the development of specific treatments that reduces the global burden of C. trachomatis infections.
|
Antiviral activity determined as inhibition of SARS-CoV-2 induced cytotoxicity of Caco-2 cells at 10 uM after 48 hours by high content imaging
|
Homo sapiens
|
-1.27
%
|
|
Title : Identification of inhibitors of SARS-CoV-2 in-vitro cellular toxicity in human (Caco-2) cells using a large scale drug repurposing collection
Year : 2020
Authors : Bernhard Ellinger, Denisa Bojkova, Andrea Zaliani, Jindrich Cinatl, Carsten Claussen, Sandra Westhaus, Jeanette Reinshagen, Maria Kuzikov, Markus Wolf, Gerd Geisslinger, Philip Gribbon, Sandra Ciesek
Abstract : To identify possible candidates for progression towards clinical studies against SARS-CoV-2, we screened a well-defined collection of 5632 compounds including 3488 compounds which have undergone clinical investigations (marketed drugs, phases 1 -3, and withdrawn) across 600 indications. Compounds were screened for their inhibition of viral induced cytotoxicity using the human epithelial colorectal adenocarcinoma cell line Caco-2 and a SARS-CoV-2 isolate. The primary screen of 5632 compounds gave 271 hits. A total of 64 compounds with IC50 <20 µM were identified, including 19 compounds with IC50 < 1 µM. Of this confirmed hit population, 90% have not yet been previously reported as active against SARS-CoV-2 in-vitro cell assays. Some 37 of the actives are launched drugs, 19 are in phases 1-3 and 10 pre-clinical. Several inhibitors were associated with modulation of host pathways including kinase signaling P53 activation, ubiquitin pathways and PDE activity modulation, with long chain acyl transferases were effective viral inhibitors.
|
Antimalarial activity against Plasmodium falciparum 3D7 after 96 hrs
|
Plasmodium falciparum
|
53.0
nM
|
|
Journal : J Med Chem
Title : Antimalarial Chemotherapy: Natural Product Inspired Development of Preclinical and Clinical Candidates with Diverse Mechanisms of Action.
Year : 2016
Volume : 59
Issue : 12
First Page : 5587
Last Page : 5603
Authors : Fernández-Álvaro E, Hong WD, Nixon GL, O'Neill PM, Calderón F.
Abstract : Natural products have played a pivotal role in malaria chemotherapy progressing from quinine and artemisinin to ozonide-based compounds. Many of these natural products have served as template for the design and development of antimalarial drugs currently in the clinic or in the development phase. In this review, we will detail those privileged scaffolds that have guided medicinal chemistry efforts yielding molecules that have reached the clinic.
|
SARS-CoV-2 3CL-Pro protease inhibition percentage at 20µM by FRET kind of response from peptide substrate
|
Severe acute respiratory syndrome coronavirus 2
|
-2.537
%
|
|
Title : Identification of inhibitors of SARS-Cov2 M-Pro enzymatic activity using a small molecule repurposing screen
Year : 2020
Authors : Maria Kuzikov, Elisa Costanzi, Jeanette Reinshagen, Francesca Esposito, Laura Vangeel, Markus Wolf, Bernhard Ellinger, Carsten Claussen, Gerd Geisslinger, Angela Corona, Daniela Iaconis, Carmine Talarico, Candida Manelfi, Rolando Cannalire, Giulia Rossetti, Jonas Gossen, Simone Albani, Francesco Musiani, Katja Herzog, Yang Ye, Barbara Giabbai, Nicola Demitri, Dirk Jochmans, Steven De Jonghe, Jasper Rymenants, Vincenzo Summa, Enzo Tramontano, Andrea R. Beccari, Pieter Leyssen, Paola Storici, Johan Neyts, Philip Gribbon, and Andrea Zaliani
Abstract : Compound repurposing is an important strategy being pursued in the identification of effective treatment against the SARS-CoV-2 infection and COVID-19 disease. In this regard, SARS-CoV-2 main protease (M-Pro), also termed 3CL-Pro, is an attractive drug target as it plays a central role in viral replication by processing the viral polyprotein into 11 non-structural proteins. We report the results of a screening campaign involving ca 8.7 K compounds containing marketed drugs, clinical and preclinical candidates, and chemicals regarded as safe in humans. We confirmed previously reported inhibitors of 3CL-Pro, but we have also identified 68 compounds with IC50 lower than 1 uM and 127 compounds with IC50 lower than 5 uM. Profiling showed 67% of confirmed hits were selective (> 5 fold) against other Cys- and Ser- proteases (Chymotrypsin and Cathepsin-L) and MERS 3CL-Pro. Selected compounds were also analysed in their binding characteristics.
|
Antiviral activity determined as inhibition of SARS-CoV-2 induced cytotoxicity of VERO-6 cells at 10 uM after 48 hours exposure to 0.01 MOI SARS CoV-2 virus by high content imaging
|
Chlorocebus sabaeus
|
-0.08
%
|
|
Antiviral activity determined as inhibition of SARS-CoV-2 induced cytotoxicity of VERO-6 cells at 10 uM after 48 hours exposure to 0.01 MOI SARS CoV-2 virus by high content imaging
|
Chlorocebus sabaeus
|
-0.08
%
|
|
Title : Cytopathic SARS-Cov2 screening on VERO-E6 cells in a large repurposing effort
Year : 2020
Authors : Andrea Zaliani, Laura Vangeel, Jeanette Reinshagen, Daniela Iaconis, Maria Kuzikov, Oliver Keminer, Markus Wolf, Bernhard Ellinger, Francesca Esposito, Angela Corona, Enzo Tramontano, Candida Manelfi, Katja Herzog, Dirk Jochmans, Steven De Jonghe, Winston Chiu, Thibault Francken, Joost Schepers, Caroline Collard, Kayvan Abbasi, Carsten Claussen , Vincenzo Summa, Andrea R. Beccari, Johan Neyts, Philip Gribbon and Pieter Leyssen
Abstract : Worldwide, there are intensive efforts to identify repurposed drugs as potential therapies against SARS-CoV-2 infection and the associated COVID-19 disease. To date, the anti-inflammatory drug dexamethasone and (to a lesser extent) the RNA-polymerase inhibitor remdesivir have been shown to be effective in reducing mortality and patient time to recovery, respectively, in patients. Here, we report the results of a phenotypic screening campaign within an EU-funded project (H2020-EXSCALATE4COV) aimed at extending the repertoire of anti-COVID therapeutics through repurposing of available compounds and highlighting compounds with new mechanisms of action against viral infection. We screened 8702 molecules from different repurposing libraries, to reveal 110 compounds with an anti-cytopathic IC50 < 20 µM. From this group, 18 with a safety index greater than 2 are also marketed drugs, making them suitable for further study as potential therapies against COVID-19. Our result supports the idea that a systematic approach to repurposing is a valid strategy to accelerate the necessary drug discovery process.
|
Inhibition of quorum sensing system in Chromobacterium violaceum ATCC 31532 assessed as reduction in violacein production at 400 uM relative to control
|
Chromobacterium violaceum
|
90.6
%
|
|
Journal : Bioorg Med Chem Lett
Title : Chloroquine fumardiamides as novel quorum sensing inhibitors.
Year : 2020
Volume : 30
Issue : 16
First Page : 127336
Last Page : 127336
Authors : Beus M,Savijoki K,Patel JZ,Yli-Kauhaluoma J,Fallarero A,Zorc B
Abstract : Quorum sensing inhibitors (QSIs) that specifically interfere with bacterial cell-to-cell communication are considered as an alternative approach to conventional antibacterial therapy. In our study, a set of twenty-six fumardiamides with a quinoline head-group were evaluated as potential QSIs. Two strains of Gram-negative Chromobacterium violaceum (violacein-producing strain ATCC31532 and violacein-negative, mini-Tn5 mutant derivative CV026) were used as QS reporters for testing anti-QS and bactericidal activity of various quinoline fumardiamides. The initial screening of eighteen fumardiamides with primaquine, mefloquine and chloroquine scaffolds identified chloroquine derivatives as the most promising QSIs. Tail-group optimization of chloroquine fumardiamides led to the most active compounds 27, 29 and 30 bearing aminoethyl or piperidine moieties. At 400 µM concentration, these compounds inhibited the QS of C. violaceum strains in a manner similar to quercetin (the model QSI), while at the 40 µM concentration their inhibitory effect was twice less than that of quercetin. As none of the compounds displayed a bactericidal effect and that the QS inhibition was specific to the CV026 strain, our findings indicate that the structurally optimized chloroquine derivatives could function as quorum quenching (QQ) agents with a potential to block the signaling without entering the cell. In conclusion, our finding provides an important step toward the further design of agents targeting cell-to-cell communication.
|
Inhibition of quorum sensing in Chromobacterium violaceum ATCC 31532 assessed as reduction in violacein production at 40 uM relative to control
|
Chromobacterium violaceum
|
90.6
%
|
|
Journal : Bioorg Med Chem Lett
Title : Chloroquine fumardiamides as novel quorum sensing inhibitors.
Year : 2020
Volume : 30
Issue : 16
First Page : 127336
Last Page : 127336
Authors : Beus M,Savijoki K,Patel JZ,Yli-Kauhaluoma J,Fallarero A,Zorc B
Abstract : Quorum sensing inhibitors (QSIs) that specifically interfere with bacterial cell-to-cell communication are considered as an alternative approach to conventional antibacterial therapy. In our study, a set of twenty-six fumardiamides with a quinoline head-group were evaluated as potential QSIs. Two strains of Gram-negative Chromobacterium violaceum (violacein-producing strain ATCC31532 and violacein-negative, mini-Tn5 mutant derivative CV026) were used as QS reporters for testing anti-QS and bactericidal activity of various quinoline fumardiamides. The initial screening of eighteen fumardiamides with primaquine, mefloquine and chloroquine scaffolds identified chloroquine derivatives as the most promising QSIs. Tail-group optimization of chloroquine fumardiamides led to the most active compounds 27, 29 and 30 bearing aminoethyl or piperidine moieties. At 400 µM concentration, these compounds inhibited the QS of C. violaceum strains in a manner similar to quercetin (the model QSI), while at the 40 µM concentration their inhibitory effect was twice less than that of quercetin. As none of the compounds displayed a bactericidal effect and that the QS inhibition was specific to the CV026 strain, our findings indicate that the structurally optimized chloroquine derivatives could function as quorum quenching (QQ) agents with a potential to block the signaling without entering the cell. In conclusion, our finding provides an important step toward the further design of agents targeting cell-to-cell communication.
|
Inhibition of mitochondrial COX1 expression in human GFP-labelled MDA-MB-231 cells at 30 uM incubated for 72 hrs under low oxygen condition by Western blot analysis
|
Homo sapiens
|
30.0
%
|
|
Journal : ACS Med Chem Lett
Title : Impact of Mitochondrial Targeting Antibiotics on Mitochondrial Function and Proliferation of Cancer Cells.
Year : 2021
Volume : 12
Issue : 4.0
First Page : 579
Last Page : 584
Authors : Cochrane EJ,Hulit J,Lagasse FP,Lechertier T,Stevenson B,Tudor C,Trebicka D,Sparey T,Ratcliffe AJ
Abstract : Some marketed antibiotics can cause mitochondria dysfunction via inhibition of the mitochondrial translation process. There is great interest in exploiting such effects within a cancer setting. To enhance accumulation of antibiotics within the mitochondria of cancer cells, and therefore delivery of a greater potency payload, a mitochondrial targeting group in the form of a triphenylphosphonium (TPP) cation was appended via an alkyl chain length consisting of 7 to 11 carbons to the ribosomal antibiotics azithromycin and doxycycline. Using MDA-MB-231 cells, the effects of each subseries on mitochondrial translation, mitochondrial bioenergetics, and cell viability are described.
