Molecular detection of Mycobacterium tuberculosis   in pulmonary and extrapulmonary samples in a hospital-based study

Objective: Tuberculosis (TB), caused by Mycobacterium tuberculosis (Mtb), remains a deadly infectious disease. India contributes to one-third of the global TB burden. However, no studies have been carried out in the Telangana (Hyderabad) population using real-time polymerase chain reaction (RT-PCR). Therefore, the current study evaluated the role of RT-PCR as a rapid and non-invasive test to diagnose TB by testing for pulmonary tuberculosis (PTB) and extrapulmonary tuberculosis (EPTB).
Materials and methods: This hospital-based study examined 1670 samples (900 EPTB; 770 PTB) comprising tissue (n = 537), peritoneal fluid (n = 420), sputum (n = 166), bronchial fluid (n = 126), cerebrospinal fluid (n = 145), ascetic fluid (n = 76), sputum pus (n = 78), urine (n = 79), and bronchoalveolar fluid (n = 43) samples. DNA from samples was separated using specific isolation kits and subjected to RT-PCR.
Results: In this study, we enrolled 1670 subjects and categorized 54.4% as females and 45.6% as males. The collected samples were categorized as 48.5% of fluid samples, followed by tissue (32.2%), sputum (9.9%), urine (4.7%), and pus-swab (4.6%). RT-PCR analysis revealed that 4.7% patients were positive for Mtb. Our results revealed that 61% of the affected patients were male and 39% were female. Among the specimen types, tissue samples gave the highest proportion of positive results (36.3%).
Conclusion: The results showed that RT-PCR should be implemented and given top priority in TB diagnosis to save time and facilitate a definitive diagnosis. Tissue samples are highly recommended to screen the Mtb through the technique RT-PCR. Future studies should extend the technique to the global population and exome sequencing analysis should be performed to identify TB risk markers.