五种耐甲氧西林金黄色葡萄球菌检测方法的比较

摘要

Objective To evaluate the rapid and accurate methods for the detection of methicillin-resistant Staphylococcus aureus (MRSA).Methods A total of 158 isolates of Staphylococcus aureus and 12 isolates of Staphylococcus epidermidis were collected from clinical specimens of Shanghai Seventh People's Hospital,and were determined by MRSA ID chromogenic culture medium,oxacillin minimum inhibitory concentration (MIC),cefoxitin disk diffusion and penicillin binding protein 2a (PBP2a) latex agglutination for the detection of MRSA.The results were compared with those of fluorescence polymerase chain reaction (PCR) for mecA gene.Results The MRSA ID chromogenic culture medium detected 124 isolates,and the sensitivity and specificity were 100.0％ and 91.9％.The cefoxitin disk diffusion detected 119 isolates,and the sensitivity and specificity were all 100.0％.The oxacillin MIC detected 117 isolates,and the sensitivity and specificity were 97.5％ and 98.4％.The PBP2a latex agglutination detected 117 isolates,and the sensitivity and specificity were 98.3％ and 100.0％.When the 4 kinds of methods compared with the PCR,Kappa values were ≥0.75,and had a good consistency.Conclusions Cefoxitin disk diffusion for the detection of MRSA has the highest sensitivity and specificity.Compared with conventional methods,MRSA ID chromogenic culture medium for the detection of MRSA shortens the report time for 24h,and it is a fast,simple and convenient method for the detection of MRSA with good specificity.%目的 评价快速、准确检测耐甲氧西林金黄色葡萄球菌(MRSA)的方法.方法 收集上海市第七人民医院临床分离的金黄色葡萄球菌158株、表皮葡萄球菌12株、溶血葡萄球菌10株、人葡萄球菌1株,用MRSAID产色培养基法、苯唑西林最低抑菌浓度(MIC)法、头孢西丁纸片扩散法、青霉素结合蛋白(PBP2a)乳胶凝集法4种方法检测MRSA,并与荧光聚合酶链反应(PCR)检测mecA基因进行比较.结果 MRSA ID产色培养基法检出MRSA 124株,敏感性和特异性分别为100.0％、91.9％,头孢西丁纸片扩散法检出MRSA 119株,敏感性和特异性均为100.0％,苯唑西林MIC法检出MRSA 117株,敏感性和特异性分别为97.5％、98.4％,PBP2a乳胶凝集法检出MRSA 117株,敏感性和特异性分别为98.3％和100.0％,4种方法与PCR比较Kappa值均≥0.75,具有较好的一致性.结论 头孢西丁纸片扩散法检出MRSA的敏感性和特异性最高,ID产色培养基法检测MRSA比常规方法报告时间缩短24 h,是一种快速、简便、特异性好且便于临床实验室检测MRSA的方法.