In vitro activity of cefoxitin and parenterally administered cephalosporins against anaerobic bacteria.

The in vitro activity of cefoxitin against 221 recent isolates of anaerobic bacteria was compared with that of cefamandole and cefuroxime by the agar dilution technique. At achievable serum levels of 32 micrograms/ml, all three drugs were active against most groups of anaerobic bacteria tested. Cefoxitin was active against most strains of the Bacteroides fragilis group, whereas cefamandole and cefuroxime were relatively ineffective. Cefoxitin was least active against Clostridium species other than Clostridium perfringens, whereas cefamandole was very active and cefuroxime moderately active. A review of recent in vitro studies with cefoxitin and parenterally administered cephalosporins indicates that cefoxitin is the most active compound against the B. fragilis group and is least active against Clostridium species other than C. perfringens.