实时荧光PCR在呼吸道感染耐甲氧西林金黄色葡萄球菌检测中的临床应用  

Clinical application of Real-time fluorescence PCR in detection of methicillin-resistant Staphylococcus aureus in respiratory tract infection

作　　者：李科[1] 马珍[1] 

机构地区：[1]重庆市急救医疗中心,重庆400014

出　　处：《中国微生态学杂志》2015年第3期331-334,共4页Chinese Journal of Microecology

摘　　要：目的评价实时荧光PCR(RT-PCR)用于检测呼吸道感染耐甲氧西林金黄色葡萄球菌(MRSA)中的方法学特性,为临床快速诊断呼吸道MRSA定植或感染提供可靠循证依据。方法通过RT-PCR技术对痰液标本中金黄色葡萄球菌(SA)特异性核酸酶编码基因nuc和MRSA的特异性耐药基因mec A进行定量检测,并同时以细菌培养、鉴定和MRSA耐药表型确诊实验作为参考方法,评价其灵敏度、特异度、阴阳性预测能力;用10倍梯度稀释法配制已知标准菌株菌悬液评估RT-PCR的最低检出限。结果 RT-PCR法较细菌培养法对MRSA检测的总符合率为97.5%,检测SA的敏感度为97.2%、特异度为98.2%、阳性预测值为92.1%、阴性预测值为99.4%,检测甲氧西林耐药性的敏感度为100%、特异度为97.7%、阳性预测值为85.2%、阴性预测值为100%;RT-PCR对nuc基因和mec A基因的最低检出限均为103/m L。结论RT-PCR法与细菌培养法对于检测MRSA差异无统计学意义,且灵敏度优于后者,是用于临床快速排除性筛查呼吸道感染MRSA的较佳检测方法。Objective To evaluate the methodological features of real-time PCR （RT-PCR） in detecting methicillin-resistant Staphylococcus aureus （MRSA） in respiratory tract infection, and provide reliable evidence-based basis for rapid clinical diagnosis of respiratory tract colonization or infection with MRSA. Methods RT-PCR technique was used to quantitatively test the specific nuc gene encoding Staphylococcus aureus （SA） nuclease and the specific resistant mecA gene of MRSA in sputum specimens, and bacterial culture, identification and drug resistance phenotype determination of MRSA were used as the reference methods to evaluate the sensitivity, specificity, and the positive and negative predictive values ; bacterial suspensions of the standard strains were prepared by using 10-fold gradient dilution method for evaluation of the minimum detection limit of RT-PCR. Results Compared with the bacterial culture method, the total accuracy of RT-PCR was 97.5% ; the sensitivity and specificity were 97. 2% and 98.2% respectively for SA, and 100% and 97. 7% respectively for MRSA; the positive and negative predictive values were 92. 1% and 99.4% respectively for SA, and 85.2% and 100% respectively for MRSA. The minimum detection limit of RT-PCR in detection of nuc gene and mecA gene were both 103/mL. Conclusion There is no significant difference between RT-PCR and bacterial culture for detection of MRSA, and the sensitivity of the former is superior, which could be a better way to rapidly exclusively screen respiratory tract infections caused by MRSA.

关 键 词：耐甲氧西林金黄色葡萄球菌 实时荧光聚合酶链反应 MECA基因 nuc基因 

分 类 号：R446.9[医药卫生—诊断学]