Reevaluation of contemporary laboratory methods for detection of antimicrobial resistance among enterococci.
OBJECTIVE: To evaluate broth microdilution, disk diffusion, Etest and Vitek Systems for susceptibility testing of enterococci. METHODS: Susceptibility testing of a panel of 149 enterococci (99 vancomycin-resistant) strains, using the study methods, was performed and the results compared. RESULTS: For vancomycin susceptibility testing, categorical agreement of disk diffusion, Etest and Vitek with the reference broth microdilution test was > 95%. For aminoglycoside and ampicillin testing, categorical agreement between Etest and Vitek was 98 to 100%. CONCLUSIONS: Disk diffusion, Etest and Vitek have acceptable performance for detection of vancomycin resistance of Van A and Van B phenotypes among enterococci.
Cormican
Martin G.
MG
Medical Microbiology Division, Department of Pathology, University of Iowa College of Medicine, Iowa City, Iowa.
Biedenbach
Douglas
D
Jones
Ronald N.
RN