[In vitro and in vivo antimicrobial activities of cefmetazole against Bacteroides fragilis].

Cefmetazole was investigated on stability to beta-lactamases produced by Bacteroides fragilis and on therapeutic effects in mice infected with B. fragilis. 1. Cefmetazole, like other cephamycins, was found extremely stable to beta-lactamases obtained from B. fragilis. 2. Cefmetazole showed good antimicrobial activities to 50 strains of B. fragilis and extremely high stability to their beta-lactamases. 3. Cefmetazole showed an excellent protecting effect to infections due to beta-lactamase producing B. fragilis. 4. Cefmetazole exhibited an excellent chemotherapeutic effect against polymicrobial infections in mice due to E. coli (beta-lactamase -)and B. fragilis (beta-lactamase +).