Interpretive criteria for cefodizime in vitro susceptibility tests with Neisseria gonorrhoeae

Abstract

Cefodizime was tested against 100 strains of Neisseria gonorrhoeae with varying susceptibility patterns to penicillin. Agar-dilution minimum inhibitory concentrations (MIC) and disk diffusion susceptibility testing were performed in triplicate for each strain according to National Committee for Clinical Laboratory Standards (NCCLS) guidelines to establish susceptibility interpretive criteria for this beta-lactamase-stable cephalosporin. Cefodizime was very active against these strains of N. gonorrhoeae, with a MIC50 of only 0.008 microgram/ml. Because no resistant strains were documented, a single susceptible criterion of < or = 0.05 microgram/ml (> or = 31 mm) was proposed to predict clinical success after a single intramuscular (i.m.) dose.