痰标本甲氧西林耐药金黄色葡萄球菌培养与聚合酶链反应快速检测方法的比较

Detection of methicillin-resistant S.aureus from respiratory specimens of ICU patients by conventional sputum culture compared with rapid polymerase chain reaction assay

目的评价聚合酶链反应(PCR)快速检测耐甲氧西林金黄色葡萄球菌(MRSA)方法在痰标本中的应用。方法同时采集痰标本送细菌培养、真菌培养和PCR快速检测,以细菌培养方法为金标准,评价PCR方法的灵敏度和特异度。结果 PCR方法检测痰标本MRSA的灵敏度为88.9%,特异度为73.6%,阳性预测值为36.4%,阴性预测值为97.5%,均较文献报道的鼻拭子PCR的灵敏度和特异度低。结论将痰标本PCR检测MRSA用于临床动态监测MRSA的流行尚缺乏进一步的数据支持,但PCR结果不受其他细菌生长的影响,而且阴性预测值高达97.5%,在排除MRSA感染或定植方面有一定价值。

Objective To evaluate the performance of polymerase chain reaction （PCR）‐based rapid detection of methicillin‐resistant S .aureus （MRSA） from the respiratory specimens of ICU patients in comparison with conventional sputum culture . Methods We collected 3 respiratory specimens from each patient simultaneously for bacterial culture ,fungal culture and PCR‐based detection of MRSA .The performance of the established PCR method was compared with the results of sputum culture in terms of sensitivity ,specificity ,positive predictive value （PPV） and negative predictive value （NPV） .Results The sensitivity , specificity ,PPV and NPV of PCR assay were 88 .9% ,73 .6% ,36 .4% ,and 97 .5% ,respectively ,which were lower than the reported results of PCR assay with nasal swabs .Conclusions The utility of PCR assay for active screening of MRSA from respiratory specimens still needs further supportive data .However ,PCR assay is somewhat informative in excluding MRSA infection or colonization because of its high NPV .