Abstract
The minimal inhibitory concentration (MIC) of vancomycin (VCM), as measured using the MicroScan WalkAway® prompt method (MW prompt), for treating methicillin-resistant Staphylococcus aureus (MRSA) has been reported to be higher than that measured using other automated susceptibility testing methods or the turbidity method. Therefore, the efficacy of VCM therapy in treating MRSA infections with an MIC of 2μg/ml of VCM, measured using MW prompt, remains unclear. In this study, we investigated the clinical and bacteriological efficacy of VCM therapy in 11 cases of MRSA pneumonia with an MIC of 1μg/ml (MIC-1 group) or 2μg/ml (MIC-2 group) of VCM as measured using MW prompt. Bacteriological success rate was 50% in the MIC-1 group but 0% in MIC-2 group. Clinical success rate was obtained in 67% of the MIC-1 group and in 20% of the MIC-2 group. In conclusion, similar to previous studies, the present study revealed that the efficacy of VCM therapy in treating MRSA with an MIC of 2μg/ml of VCM, measured using MW prompt, is lower than that with an MIC of 1μg/ml of VCM.
