Establishment of MICs of moxalactam for control and reference anaerobic organisms in agar dilution and microdilution techniques

Abstract

The MICs of moxalactam were determined for eight National Committee for Clinical Laboratory Standards control and reference strains and for Fusobacterium nucleatum ATCC 10953 by agar and microdilution techniques. The recommended MIC for the control strain Bacteroides fragilis in both agar and microdilution tests is 0.5 micrograms/ml. Recommended MICs for Bacteroides thetaiotaomicron ATCC 29741 and Clostridium perfringens ATCC 13124 by agar dilution are 8 and 0.063 micrograms/ml, respectively. These two strains gave inconsistent results in microdilution tests. Variation in results with microdilution procedures was seen, which illustrates problems in reading endpoints and with modifications of media. Recommended MICs for the reference strains are presented.