Beta-lactamase stability of cefoxitin in comparison with other beta-lactam compounds.

The beta-lactamase stability of cefoxitin, the second-generation cephamycin compound, was compared with that of cefamandole, cefoperazone, cefotaxime, moxalactam, carbenicillin, and piperacillin. Unlike cefamandole, cefoperazone, carbenicillin, and piperacillin, cefoxitin was not hydrolyzed by the common plasmid beta-lactamases, TEM-1, TEM-2, OXA-2, and SHV-1. Cefoxitin and moxalactam were the only agents stable to all chromosomal beta-lactamases, whereas cefamandole, cefoperazone, cefotaxime, carbenicillin, and piperacillin were destroyed by cephalosporinases of Proteus vulgaris and Bacteroides fragilis.