Disk diffusion susceptibility of Branhamella catarrhalis and relationship of beta-lactam zone size to beta-lactamase production.
We tested 231 isolates of Branhamella catarrhalis for beta-lactamase production and drug susceptibility by the National Committee for Clinical Laboratory Standards disk diffusion method. The nitrocephin disk (Cefinase) identified beta-lactamase in 98% of the enzyme-producing strains, and a zone diameter of inhibition of less than or equal to 29 mm for penicillin correctly predicted the presence of beta-lactamase in 99% of the isolates. No resistance to erythromycin, tetracycline, trimethoprim-sulfamethoxazole, or amoxicillin-clavulanic acid was observed.
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D008712:Methicillin / Q000494:pharmacology; D008826:Microbial Sensitivity Tests; D009016:Moraxella / Q000187:drug effects* / Q000201:enzymology; D010400:Penicillin G / Q000494:pharmacology; D001618:beta-Lactamases / Q000096:biosynthesis*
D000900:Anti-Bacterial Agents; D001618:beta-Lactamases; D010400:Penicillin G; D008712:Methicillin