Department of Laboratory Medicine, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan.
J Clin Microbiol. 2011 Mar;49(3):797-801. doi: 10.1128/JCM.01839-10. Epub 2010 Dec 22.
The Cobas TaqMan MTB test, based on real-time PCR technology, was evaluated for direct detection of Mycobacterium tuberculosis complex (MTBC) in respiratory specimens. A total of 1,093 samples from 446 patients, including 118 acid-fast smear-positive and 975 acid-fast smear-negative specimens, were investigated. Diagnostic cultures performed with 7H11 agar, Löwenstein-Jensen medium, and the Bactec MGIT 960 system were considered the reference methods. When discrepant results between the Cobas TaqMan MTB test and culture occurred, additional results from the BD MGIT TBc identification test and the GenoType Mycobacterium CM test performed on growth-positive and acid-fast-stain-positive MGIT tubes and review of the patient's medical history were used for discrepancy analysis. The overall sensitivity, specificity, positive predictive value, and negative predictive value for the Cobas TaqMan MTB test were 91.5%, 98.7%, 91.5%, and 98.7%, respectively. In general, the performance of the new Cobas TaqMan MTB test was comparable to that of the replaced Cobas Amplicor MTB system. The most prominent feature of the new system was its extraordinarily high sensitivity (79.5%) for detecting MTBC in smear-negative specimens; out of 44 smear-negative but culture-positive specimens, 35 were positive by the new system. The Cobas TaqMan MTB assay, including DNA extraction, can be completed within 3 h.
罗氏 Cobas TaqMan MTB 检测，基于实时 PCR 技术，用于直接检测呼吸道标本中的结核分枝杆菌复合群（MTBC）。共检测了 446 名患者的 1093 个样本，包括 118 个抗酸染色阳性和 975 个抗酸染色阴性的样本。7H11 琼脂、 Löwenstein-Jensen 培养基和 Bactec MGIT 960 系统的诊断培养被认为是参考方法。当 Cobas TaqMan MTB 检测与培养结果不一致时，通过对生长阳性和抗酸染色阳性的 MGIT 管进行 BD MGIT TBc 鉴定试验和 GenoType Mycobacterium CM 试验，以及回顾患者的病史，对差异进行分析。Cobas TaqMan MTB 检测的总敏感性、特异性、阳性预测值和阴性预测值分别为 91.5%、98.7%、91.5%和 98.7%。总体而言，新的 Cobas TaqMan MTB 检测的性能与被替代的 Cobas Amplicor MTB 系统相当。新系统最显著的特点是其对阴性标本中 MTBC 的检测灵敏度极高（79.5%）；在 44 份阴性但培养阳性的标本中，有 35 份是新系统阳性的。Cobas TaqMan MTB 检测，包括 DNA 提取，可在 3 小时内完成。
