Recovery rates of mycobacterium from suspected extra-pulmonary tuberculosis patients using liquid culture at a tertiary referral centre of India

Abstract

Tuberculosis still remains a serious public health problem in developing countries. Rapid isolation of mycobacteria is critical for accurate diagnosis and management of tuberculosis. In the present study BACTEC MGIT 960 system was evaluated against Lowenstein Jensen (LJ) medium for isolation of mycobacteria from different extra-pulmonary specimens (N = 371). The samples were processed using NaOH-NALC method and inoculated in BACTEC MGIT and on LJ medium. The BACTEC MGIT 960 system detected 93 (25.06%) samples positive for acid fast bacilli and by LJ only 38 samples (10.24%) was positive. Furthermore, total 99 (26.68%) samples were detected positive by both the culture methods. The mean turnaround time to detection of mycobacteria by MGIT 960 were significantly less (12.4 days) as compared with LJ (22.76 days). In conclusion, BACTEC MGIT 960 system is more sensitive and rapid culture system for isolation of mycobacteria. However LJ culture method also suggested to further increase the detection rate of EPTB cases.

Keywords: Extra-pulmonary tuberculosis; MGIT 960; N-Acetyl-l-cysteine.