title: Cephamycin inactivation due to enzymatic hydrolysis by beta-lactamase from Bacteroides fragilis.
abstract: The susceptibility of 53 clinical isolates of Bacteroides fragilis to cephamycins was examined. Judging from the MICs for 50% of the strains tested, moxalactam was the most active, however, judging from the MICs for 90% of the strains tested, cefbuperazone was more effective than moxalactam. A correlation was observed between in vitro activity of benzylpenicillin and cephaloridine and beta-lactamase production. Inactivation due to enzymatic hydrolysis of cephamycins over a short time was not observed; however, inactivation was detected by a double disk diffusion test, and moxalactam was most easily inactivated. We conclude that inactivation due to enzymatic hydrolysis of cephamycins over a long time may play an important role in resistance to some cephamycins in strains of B. fragilis.
mesh_terms: D001441:Bacteroides fragilis / Q000187:drug effects / Q000201:enzymology*; D002511:Cephalosporins / Q000378:metabolism / Q000494:pharmacology; D002513:Cephamycins / Q000378:metabolism* / Q000494:pharmacology; D019818:Clavulanic Acid; D002969:Clavulanic Acids / Q000494:pharmacology; D006868:Hydrolysis; D008826:Microbial Sensitivity Tests; D009070:Moxalactam / Q000494:pharmacology; D010400:Penicillin G / Q000494:pharmacology; D065093:beta-Lactamase Inhibitors; D001618:beta-Lactamases / Q000378:metabolism*
chemical_list: D002511:Cephalosporins; D002513:Cephamycins; D002969:Clavulanic Acids; D065093:beta-Lactamase Inhibitors; D019818:Clavulanic Acid; D001618:beta-Lactamases; D010400:Penicillin G; D009070:Moxalactam