Int.J.Curr.Microbiol.App.Sci (2020) 9(3): 308-312 308 Original Research Article https://doi.org/10.20546/ijcmas.2020.903.036 Diagnostic Role of Polymerase Chain Reaction and Inadequacy of Mycobacterium Growth Indicator Tube culture in Tuberculous Pleuritis Gandhi Kandhakumari 1 * and Selvaraj Stephen 2 1 Kanti Devi Medical College and Research Centre, Mathura, Uttar Pradesh-281406, India 2 Department of Microbiology, Mahatma Gandhi Medical College & Research Institute, SBV University, Pillaiyarkuppam, Pondicherry - 607403, India *Corresponding author ABSTRACT Introduction India, a developing country with high tuberculosis endemicity accounts for highest incident cases of 27% among the total cases reported worldwide (WHO, 2018). Pleural tuberculosis ranks second next to tuberculous lymphadenitis and India accounts for 30-80% of cases. Though pleural biopsy is reported as the optimum specimen for definitive diagnosis of tuberculous pleural effusion, pleural fluid is commonly collected for diagnostic purpose (SK Sharma et al., 2004; P James et al., 2010). Because pleural fluid tends to be paucibacillary it turns out to be negative in 80 to 90% cases making conventional microbiological techniques like smear and culture least sensitive. But molecular techniques which detect and amplify specific regions of M. tuberculosis International Journal of Current Microbiology and Applied Sciences ISSN: 2319-7706 Volume 9 Number 3 (2020) Journal homepage: http://www.ijcmas.com Diagnosis and management of patients with tuberculous pleuritis needs a rapid and sensitive diagnostic tool. Our aim was to diagnose cases of tuberculous pleuritis from patients employing ZN smear, culture (LJ & MGIT) and to compare with PCR. Pleural fluid collected from 36 patients with clinical and/or radiological suspicion of TB pleuritis was included in this study. Pleural fluid collected from nine non-tuberculous pleuritis cases was included as negative controls. Pleural fluid samples were analyzed for ZN smear, LJ and automated MGIT culture and results compared with MTB PCR targeting IS6110 region. Positivity for smear, LJ, MGIT and PCR individually were 5.6%, 2.8%, 16.7% and 25% respectively. Combination of all above techniques together increased the percentage positivity to 30.6%. Negative controls were negative by all procedures. In the context of paucibacillary specimens like pleural fluid, smear microscopy and LJ are less sensitive. MGIT has moderate sensitivity and rapidity compared to LJ. PCR is rapid and highly sensitive, but needs interpretation of PCR reports with “gold standard” culture and clinical history to arrive at an early and accurate diagnosis. Keywords PCR, Mycobacterium tuberculosis, Pleural fluid, LJ, IS6110 Accepted: 05 February 2020 Available Online: 10 March 2020 Article Info