mecA、femA基因PCR联合扩增法检测耐甲氧西林金黄色葡萄球菌

目的 探讨mecA、femA基因PCR联合扩增快速检测耐甲氧西林金黄色葡萄球菌(MRSA)的敏感性及特异性。方法 用纸片扩散法及mecA、femA基因PCR联合扩增检测178株葡萄球菌中的MRSA，并与琼脂稀释法的结果比较。结果 纸片扩散法筛检MRSA(耐甲氧西林凝固酶阴性葡萄球菌，MRCNS)的敏感性、特异性分别为94．4％(89．5％)、92．4％(73．7％)。在金黄色葡萄球菌中若以mecA基因阳性为判定MRSA的指标，则敏感性、特异性分别为91．7％、95.5％。在178株葡萄球菌中若以mecA、femA基因阳性作为判定MRSA的指标，特异性提高到97．9％．结论 PCR mecA、femA基因联合扩增既可用于筛检MRSA，又可免去常规生化鉴定，具快速、特异性强的优点。

Combination PCR of mecA, femA Genes for Detection of MRSA

Objective To make a comparison of PCR assay, Agar Dilution and Disk Diffusion as for detecting Staphylococcal mecA, femA genes. Methods A total of 178 strains of Staphylococci were isolated from three large scale hospitals in Chengdu. Disk Diffusion and staphylococcal mecA, femA gene PCR assay for detecting MRSA were compared with Agar Dilution. Results The sensitivity and specificity of Disk Diffusion for detecting MRSA were 94.4% and 92.4% respectively. The sensitivity and specificity of Disk Diffusion for detecting MRCNS were 89.5% and 73.7% respectively. Compared with Agar Dilution, Staphylococcus aureus mecA gene PCR assay's sensitivity and specificity were 91.7% and 95.5% respectively. In all the 178 strains of Staphylococci, mecA gene combining with femA gene PCR assay's specificity was up to 97.9%. Conclusion The detection of femA gene together with mecA gene by PCR is not only an approach for differentiating MRSA from MRCNS, but also a rapid, highly specific method which can be used as an auxiliary method in clinical microbiological laboratory.