title: Clavulanic acid, a novel inhibitor of beta-lactamases.
abstract: Clavulanic acid, Z-(2R,5R)-3-(beta-hydroxyethylidene)-7-oxo-4-oxa-1-azabicyclo-[3,2,0] heptane-2-carboxylic acid, has been shown to be an effective inhibitor of the beta-lactamases of the Richmond types II, III, IV, and V. Inhibition is a time-dependent reaction and is irreversible. Clavulanic acid had poor antibacterial activity against Staphylococcus aureus, Enterobacteriaceae, and Pseudomonas aeruginosa, with minimal inhibitory levels greater than 25 mug/ml. It did inhibit the majority of Neisseria gonorrhoeae at 0.1 mug/ml and Haemophilus influenzae at 6.3 mug/ml. Clavulanic acid acted synergistically with penicillins and cephalosporins to inhibit beta-lactamase-producing S. aureus and Enterobacteriaceae. Clavulanic acid combined with ampicillin inhibited beta-lactamase-producing N. gonorrhoeae, H. influenzae, Escherichia coli, Salmonella typhi, and Shigella sonnei.
mesh_terms: D000667:Ampicillin / Q000494:pharmacology; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects; D002511:Cephalosporins / Q000494:pharmacology; D004357:Drug Synergism; D007700:Kinetics; D008826:Microbial Sensitivity Tests; D065093:beta-Lactamase Inhibitors; D047090:beta-Lactams / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D002511:Cephalosporins; D065093:beta-Lactamase Inhibitors; D047090:beta-Lactams; D000667:Ampicillin