Effect of five irreversible inhibitors on beta-lactamase from Shigella flexneri UCSF-129.
The effect of five irreversible inhibitors on purified enzyme from Shigella flexneri USCF-129 and also in vitro, was investigated. The I50 was 0.091, 0.30, 0.40 and 0.87 microgram/ml for 6 beta-iodopenicillanic, clavulanic, olivanic and 6 beta-bromopenicillanic acids, respectively, and 255 micrograms/ml for sulbactam. The synergic responses of these inhibitors (10 micrograms/ml) were studied with ampicillin and cephradin on S. flexneri. The MIC of ampicillin was reduced by 128 times using 6 beta-iodopenicillanic, 6 beta-bromopenicillanic and clavulanic acids. This indicates that the beta-lactamase of S. flexneri is a penicillinase. Since these inhibitors have a strong action against the beta-lactamase and last for at least 6 h, further work is expected to reveal their medical value.
Campos
M
M
Department of Chemistry, Faculty of Sciences, University of Concepción, Chile.
Alarcón
M A
MA
González
H
H
Sánchez
R
R
D000667:Ampicillin / Q000494:pharmacology; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D019818:Clavulanic Acid; D002969:Clavulanic Acids / Q000494:pharmacology; D004357:Drug Synergism; D007769:Lactams; D008826:Microbial Sensitivity Tests; D010397:Penicillanic Acid / Q000494:pharmacology; D012763:Shigella flexneri / Q000201:enzymology* / Q000254:growth & development; D065093:beta-Lactamase Inhibitors; D001618:beta-Lactamases / Q000187:drug effects / Q000378:metabolism*; D047090:beta-Lactams
D000900:Anti-Bacterial Agents; D002969:Clavulanic Acids; D007769:Lactams; D065093:beta-Lactamase Inhibitors; D047090:beta-Lactams; D019818:Clavulanic Acid; C020786:olivanic acid; D000667:Ampicillin; D010397:Penicillanic Acid; D001618:beta-Lactamases