Multiplex Real-Time PCR-shortTUB Assay for Detection of the Mycobacterium tuberculosis Complex in Smear-Negative Clinical Samples with Low Mycobacterial Loads [Mycobacteriology and Aerobic Actinomycetes]

In this study, we evaluated the performance of this novel multiplex assay for detecting the MTBC in comparison with that of the conventional culture-based method. The multiplex real-time PCR-shortTUB assay targets two genes, whiB3 (redox-responsive transcriptional regulator) and pstS1 (phosphate-specific transporter), yielding limits of detection (LOD) of 10 copies and 100 copies, respectively, and amplification efficiencies of 92% and 99.7%, respectively. A total of 94 extrapulmonary samples and pulmonary samples with low mycobacterial loads (all smear negative; 75 MTBC culture positive) were analyzed using the test, yielding an overall sensitivity of 88% and a specificity of 95%. For pleural fluid and tissues/biopsy specimens, the sensitivity was 83% and 85%, respectively. In summary, this technique could be implemented in routine clinical microbiology testing to reduce the overall turnaround time for MTBC detection and may therefore be a useful tool for the diagnosis of extrapulmonary tuberculosis and diagnosis using pulmonary samples with low mycobacterial loads.

Source: Journal of Clinical Microbiology - July 25, 2019 Category: Microbiology Authors: Alcaide, F., Trastoy, R., Moure, R., Gonzalez-Bardanca, M., Ambroa, A., Lopez, M., Bleriot, I., Blasco, L., Fernandez-Garcia, L., Tato, M., Bou, G., Tomas, M., Mycobacterial and GEMARA SEIMC/REIPI Bacterial Clinical Adaptation Study Group Tags: Mycobacteriology and Aerobic Actinomycetes Source Type: research