Paule Suzanne M, Hacek Donna M, Kufner Bridget, Truchon Karine, Thomson Richard B, Kaul Karen L, Robicsek Ari, Peterson Lance R
Department of Pathology and Laboratory Medicine, Evanston Northwestern Healthcare, 2650 Ridge Avenue, Evanston, IL 60201, USA.
J Clin Microbiol. 2007 Sep;45(9):2993-8. doi: 10.1128/JCM.00670-07. Epub 2007 Jul 11.
We evaluated the use of the BD GeneOhm MRSA real-time PCR assay (BD Diagnostics, San Diego, CA) for the detection of nasal colonization with methicillin-resistant Staphylococcus aureus (MRSA). The initial evaluation consisted of 403 paired nasal swabs and was done using the specimen preparation provided with the kit and an in-house lysis method that was specifically developed to accommodate large-volume testing using a minimal amount of personnel time. One swab was placed in an achromopeptidase (ACP) lysis solution, and the other was first used for culture and then prepared according to the kit protocol. PCR was performed on both lysates, and results were compared to those for culture. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the PCR assay were 98%, 96%, 77%, and 99.7% with the kit lysate and 98%, 95%, 75%, and 99.7% with the ACP lysate (P, not significant), respectively. The second evaluation was done after implementation of all-admission surveillance using PCR with ACP lysis and a sampling of 1,107 PCR-negative samples and 215 PCR-positive samples that were confirmed by culture. The results of this sampling showed an NPV of 99.9% and a PPV of 73.5% (prevalence, 6%), consistent with our initial findings. The BD GeneOhm MRSA assay is an accurate and rapid way to detect MRSA nasal colonization. When one is dealing with large specimen numbers, the ACP lysis method offers easier processing without negatively affecting the sensitivity or specificity of the PCR assay.
我们评估了BD GeneOhm耐甲氧西林金黄色葡萄球菌（MRSA）实时聚合酶链反应检测法（BD诊断公司，加利福尼亚州圣地亚哥）用于检测鼻腔中MRSA定植的情况。初始评估包括403对鼻腔拭子，采用试剂盒提供的样本制备方法以及专门开发的内部裂解方法进行，该内部裂解方法旨在以最少的人员时间进行大批量检测。将一支拭子置于无色肽酶（ACP）裂解液中，另一支先用于培养，然后按照试剂盒方案进行制备。对两种裂解物都进行聚合酶链反应，并将结果与培养结果进行比较。使用试剂盒裂解液时，聚合酶链反应检测法的灵敏度、特异性、阳性预测值（PPV）和阴性预测值（NPV）分别为98%、96%、77%和99.7%；使用ACP裂解液时分别为98%、95%、75%和99.7%（P值无显著性差异）。第二次评估是在实施全员入院监测后进行的，采用ACP裂解的聚合酶链反应，并对1107份聚合酶链反应阴性样本和215份经培养确认的聚合酶链反应阳性样本进行抽样。该抽样结果显示NPV为99.9%，PPV为73.5%（患病率为6%），与我们的初始结果一致。BD GeneOhm MRSA检测法是检测鼻腔MRSA定植的一种准确且快速的方法。当处理大量样本时，ACP裂解方法提供了更简便的处理方式，且不会对聚合酶链反应检测法的灵敏度或特异性产生负面影响。
