Amplification of mecA Gene and Resistance Phenotype in the Evaluation of the Methods for Detection of Methicillin-resistant Strains of Staphylococci / 医学研究杂志

ABSTRACT

Objective In order to choose a suitable method in detecting MRS,the detection rate,sensitivity and specificity of Vitek-32 auto microbacteria indentity system,oxacillin agar dilution test,cefoxitin disk diffusion test and PCR for mecA gene are evaluated.Methods MRSA and MRCNS are detected by the four methods metioned above in 175 staphylococci,then comparing the postive detection rate by Chi-square test and calculating sensitivity and specificity of the other three methods based on PCR for meeA gene as a gold standard.Results The detection rate of four methods have no difference in detecting MRSA,but the detection rate of Vitek-32 auto microbacteria indentity system and oxacillin agar dilution test is better than that of PCR for mecA gene in detecting MRCNS.Sensitivity and specificity of Vitek-32 auto microbacteria indentity system,oxacillin agar dilution test and cefoxitin disk diffusion test in detecting MRSA are 100%、96.3%、96.3% and 88.2%、100%、100% respectively,the sensitivity of detecting MRCNS are all 100%,the specificity of detecting MRCNS are 50%、46.1% and 65.4% respectively.Conclusions Both mecA gene and the determination for MIC of Oxacillin should be considered in final decision for MRS,Furthermore.the MRS mediated by mecA gene and the MRS mediated by non-mecA gene should be treated differentially.