Vancomycin MIC for methicillin-resistant coagulase-negative Staphylococcus isolates: evaluation of the broth microdilution and Etest methods.

Vancomycin MIC results were determined by the broth microdilution (BMD) method and by Etest using 130 methicillin-resistant coagulase-negative staphylococcus bloodstream isolates obtained from a tertiary hospital. The majority (98.5%) of MIC results determined by BMD were ≤1 μg/ml, in contrast to MIC results determined by Etest (72.3% were ≥1.5 μg/ml). The MICs obtained by Etest were, in general, 1- to 2-fold higher than the MICs obtained by BMD.