In vitro activity of cefmetazole against extended-spectrum beta-lactamases producing and non-producing strains: a comparison with cefoxitin

ObjectiveTo determine the in vitro antimicrobial activity of cefmetazole and cefoxitin against extended-spectrum beta-lactamases(ESBLs) producing and non-producing strains.MethodsA total of 520 strains of K.pneumoniae and E.coli were isolated from January 2004 to December 2004.Phenotypic confirmatory test was used to detect ESBLs.Kirby-Bauer agar diffusion method was used for susceptibility testing.ResultsOverall,226 ESBLs-producing strains were detected.The positive rate of ESBLs was 43.5%,specifically 45.8% among E.coli isolates and 39.6% among K.pneumoniae.In vitro antimicrobial activity of cefmetazole against ESBLs producing strains was higher than that of cefoxitin in West China Hospital.ConclusionsCephamycins can be the alternative treatment for ESBLs producing strains.The in vitro antimicrobial activity of cefmetazole against ESBLs producing strains is higher than that of cefoxitin in West China Hospital.