[Sensitivity of strict anaerobic bacteria to metronidazole, cefoxitin, and clindamycin]

The minimal inhibitory concentrations of three antimicrobial agents were determined by two fold dilution in Wilkins Chalgren agar for over 569 anaerobes isolated and collected from 20 French hospitals. Metronidazole, cefoxitin and clindamycin inhibited respectively 95, 97 and 91% of tested strains. No metronidazole resistant strains could be found among Bacteroides fragilis group, Fusobacterium and Clostridium other than C. perfringens. Cefoxitin was the most active against C. perfringens, Gram positive cocci and non sporulated bacilli. Clindamycin resistance was observed mainly with B. fragilis and Clostridium other than C perfringens. This phenomenon occurred in most hospitals where strains were isolated.