Microbiology and Infectious Diseases Directorate, SA Pathology, Adelaide, South Australia, Australia.
Pathology. 2012 Dec;44(7):642-3. doi: 10.1097/PAT.0b013e328359d565.
To evaluate the SD MPT64 assay for rapid, preliminary identification of Mycobacterium tuberculosis complex (MTBC).
All specimens were processed using a standard methodology and inoculated into an automated liquid culture system (BD MGIT960). All signal positive cultures had a smear prepared and tested using a commercial molecular assay. From a carefully mixed MGIT960 vial, 100 μL of broth was loaded into the sample well, and the result recorded after 15 min. Repeat isolates from patients were excluded as were positive cultures contaminated with non-mycobacteria.
Fifty MTBC and 150 non-tuberculous mycobacteria were isolated during the study period. Test sensitivity was 98.04%, specificity (98.68%), positive predictive value (96.15%), and a negative predictive value (99.34%). There were two false positive results: Mycobacterium gastri and Mycobacterium fortuitum which were both identified by 16S rDNA and rpoB sequence analysis.
The SD MPT64 assay showed excellent performance. The major advantages are: (1) simplicity of test procedure, (2) rapid turnaround time, and (3) relatively inexpensive. When used in conjunction with the presence of serpentine cording in a stained smear from culture, a preliminary identification of MTBC may be made with high confidence.
评估 SD MPT64 检测法用于快速初步鉴定结核分枝杆菌复合群（MTBC）。
所有标本均采用标准方法处理，并接种于自动化液体培养系统（BD MGIT960）。所有信号阳性的培养物均制备涂片，并使用商业分子检测方法进行检测。从精心混合的 MGIT960 小瓶中，将 100 μL 肉汤加载到样品孔中，15 分钟后记录结果。排除来自患者的重复分离株以及与非分枝杆菌污染的阳性培养物。
在研究期间，分离出 50 株 MTBC 和 150 株非结核分枝杆菌。该检测的敏感性为 98.04%，特异性（98.68%）、阳性预测值（96.15%）和阴性预测值（99.34%）。有两个假阳性结果：胃分枝杆菌和偶然分枝杆菌，均通过 16S rDNA 和 rpoB 序列分析鉴定。
SD MPT64 检测法表现出优异的性能。主要优点有：（1）检测程序简单；（2）周转时间快；（3）相对便宜。当与培养物染色涂片上存在蛇形卷曲相结合使用时，可高度确信地对 MTBC 进行初步鉴定。
