耐甲氧西林金黄色葡萄球菌快速检测方法的比较

目的 筛选出快速检测耐甲氧西林金黄色葡萄球菌(methicillin resistant Staphylococcous aureus,MRSA)的实验方法.方法 从天津医科大学附属肿瘤医院细菌室菌库中提取源自肿瘤患者感染的44株金黄色葡萄球菌,利用苯唑西林纸片扩散法、头孢西丁纸片扩散法、微量肉汤稀释法、Etest法、青霉素结合蛋白2a(penicillin-binding protein 2a,PBP2a)乳胶凝集法5种表型检测MRSA方法进行检测,并与PCR方法进行比较.结果 PCR法检测mecA基因,确定MRSA 36株;以PCR作为金标准,苯唑西林纸片扩散法、头孢西丁纸片扩散法和苯唑西林微量肉汤稀释法检测出MRSA均为32株,敏感度和特异度均为88.9%和100%;E试验检测出MRSA为33株,敏感度与特异度分别为88.9%、87.5%;PBP2a乳胶凝集法检测出MRSA 29株,敏感度与特异度分别为80.5%、100%.结论 PBP2a乳胶凝集法比上述试验报告周期缩短24 h,是一种快速、简便、特异度好且便于临床试验室推广开展的检测MRSA方法.

Comparison in rapid detections of methicillin resistant Staphylococcus aureus

Objective To compare several methods for the rapid detection of methicillin resistant StaphylOCOCCUS aureus(MRSA).Methods Forty-four Staphylococcus aureus isolates from Tianjin Medical University Cancer Institute and Hospital(TMUCIH)were detected by Oxacillin Kirby-Bauer disk diffusion method,Cefoxitin Kirby-Bauer disk diffusion method,Oxacillin micro-broth dilution method,E tests and PBP2a Latex agglutinaltion assay.These above results were compared with PCR analysis.Results PCR analysis showed that 36 MRSA strains containing mecA was identified.Thirty-two MRSA strains were detected by Oxacillin Kirby-Bauer disk diffusion method,Cefoxitin Kirby-Bauer disk diffusion method and Oxacillin micro-broth dilution method.Compared with PCR analysis,the sensitivity and specificity is 88.9%and 100%respectively.Thirty-three MRSA strains were identified by E test,with the sensitivity of 88.9%and specificity of 87.5%.Twenty-nine MRSA strains were identified by PBP2a latex agglutination assay with the sensitivity of 80.5%and specificity of 100%.Conclusions The turnaround time of PBP2a Latex agglutination assay could be reduced 24 h compared with other methods for detection of MRSA.This rapid,convenient and specific method could be applied in clinical laboratories for MRSA detection.