Comparison of BACTEC MGIT with conventional methods for detection of Mycobacteria in clinically suspected patients of extra pulmonary tuberculosis in a tertiary care hospital

Abstract

Background: Tuberculosis is an important public health problem in India and globally.  Extra pulmonary tuberculosis (EPTB) constitutes for approximately 15 to 20 per cent of all cases of tuberculosis in immunocompetent patients and accounts for more than 50 per cent of the cases in HIV- positive individuals. Main problem with the extra-pulmonary tuberculosis is the paucibacillary nature of the specimen, which makes the diagnosis difficult and delay the treatment. With this in background, this study aimed at the isolation of Mycobacteria from clinical specimens of patients suspected of extra pulmonary tuberculosis using BACTEC MGIT, Lowenstein Jensen (LJ) media and direct acid-fast bacilli smear examination.Methods: A total of 66 samples were processed for direct AFB smear examination, and culture on MGIT and LJ media. Acid fast staining of the specimens was done using the Ziehl-Neelsen method.Results: Among 66 specimens, MGIT gave a higher yield of mycobacteria (46.9%), lower contamination rate (3%) and shorter time to positive culture as compared to LJ media.Conclusions: MGIT gives higher yield and faster results.