Evaluation of molecular identification methods for detection of Mycobacterium tuberculosis complex from clinical specimen

• Main Authors: Ying-Ju Pan, 潘瀅如
• Other Authors: 吳雪霞
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/04463580540822553617

碩士 === 臺北醫學大學 === 醫學檢驗暨生物技術學系 === 101 === Tuberculosis remains a highly prevalent disease in the world, especially in the undeveloped and developing countries. The resurgence of tuberculosis has created a global public health emergency. Currently, the diagnosis of tuberculosis mainly relies on cultures of Mycobacterium tuberculosis from clinical specimens. However, the diagnosis and treatment of tuberculosis are often delayed due to the slow growth of Mycobacterium tuberculosis, which usually takes 4 to 6 weeks. In recent years, the development and application of molecular identification techniques allow operators to timely detect Mycobacterium. This study collected 108 sputum samples from 37 patients. After digesting, decontaminating and neutralization the specimen, we performed the Mycobacterial culture and acid-fast staining. On the other hand, the mRNA and DNA were extracted from decontaminated specimens. The mRNA then was reverse transcribed into cDNA. We used a real-time PCR assay for M. tuberculosis complex, the Cobas TaqMan MTB test (Roche Diagnostics, Basel,Switzerland). Finally, the results were compared to culture findings. The overall Sensitivity, Specificity, Positive predictive values (PPV), Negative predictive values (NPV), Prevalence and Efficiency were 90.00%, 79.17%, 84.38% 86.36%, 55.56% and 85.19%, respectively, for DNA Real time PCR, and 96.67%, 79.17%, 85.29% 95.00%, 55.56%and 88.89%, respectively, for mRNA RT-Real time PCR. Furthermore, the mRNA RT-Real time PCR showed a higher sensitivity than DNA Real time PCR. The overall agreement between the culture and mRNA RT-Real time PCR results was 88.89%, which was significantly better than between the culture and DNA Real time PCR results (88.89% V.S. 85.19%). We concluded that the mRNA RT-Real time PCR is a useful molecular identification technique to shorten the detection time and provide accurate identification of M. tuberculosis complex directly from clinical specimens.