6种检测耐甲氧西林金黄色葡萄球菌方法的应用评价

Evaluation of six methods for detection of methicillin-resistant staphylococcus aureus

目的对6种耐甲氧西林金黄色葡萄球菌检测方法进行应用评价。方法分别采用6种方法检测134株临床分离的金黄色葡萄球菌耐甲氧西林的情况:聚合酶链反应(PCR)检测mecA基因、苯唑西林纸片扩散法、头孢西丁纸片扩散法、琼脂稀释法检测苯唑西林最小抑菌浓度、琼脂稀释法检测头孢西丁最小抑菌浓度、显色培养基法。结果以PCR检测mecA基因为"金标准",65.7%的金黄色葡萄球菌耐甲氧西林;苯唑西林纸片扩散法检测耐甲氧西林金黄色葡萄球菌的敏感性和特异性分别为95.5%和97.8%;头孢西丁纸片扩散法敏感性和特异性分别为97.7%和97.8%;苯唑西林和头孢西丁琼脂稀释法敏感性均为100%,特异性分别为97.8%和91.3%;显色培养基法敏感性和特异性分别为98.9%和97.8%。结论 6种检测方法具有较好的一致性。头孢西丁纸片扩散法简便、可靠,可作为临床实验室常规检测MRSA的方法。

【Objective】 To evaluate the reliability and clinical practicability of six methods in detection of methicillin-resistant Staphylococcus aureus（MRSA）.【Methods】 A total of 134 strains of clinical isolated staphylococcus aureus were simultaneously assayed by PCR amplification of mecA gene,oxacillin disc diffusion test,cefoxitin disc diffusion test,oxacillin agar dilution test,cefoxitin agar dilution test,and chromogenic media test.【Results】 65.7% of Staphylococcus aureus were confirmed as methicillin-resistant by means of PCR amplification of mecA gene,which was used as a reference method（or gold standard） in the current study.The oxacillin disc diffusion test＇s sensitivity and specificity for MRSA is 95.5% and 97.8%,respectively,while it was 97.7% and 97.8% for cefoxitin disc diffusion test.The oxacillin agar dilution test＇s sensitivity and specificity is 100% and 97.8%,respectively,while it was 100% and 91.3% for cefoxitin agar dilution test.The chromogenic media test＇s sensitivity and specificity is 98.9% and 97.8%,respectively.【Conclusions】 All of the six methods are suitable for clinical laboratories to accurately detecting MRSA.Oxacilin disc diffusion test is cost-effective and easy to processing,which can be a reliable and conventional method for routine detection of MRSA.