A comparative study of mycobacteria detected by BACTEC method and LJ medium

Background: Tuberculous pleural effusion has been known to phuysicians since antiquity, having been well des ribed by Hippocrates and Celsus. Involvement of the pleural surfaces in patients with tuberculosis is still one of the two most common extraparenchymal manifestation of tuberculosis (TB), the other being lymphatic involvement. Pleural effusion accounts for 26.6% of extra pulmonary TB. In India, TB is the most common cause of pleural effusion. Objective: To compare the results obtained by BACTEC method and LJ medium Methods: A hospital based cross sectional study was conducted among 60 patients. Institutional Ethic Committee permission was obtained. Informed consent was taken from patients. Data was recorded by taking history, thorough clinical examination, and investigations were done. Results: The results of BACTEC culture (radiometric) showed that there were 15 cultures positive out of 60 cultures (25%). The week wise analysis ofthese positive results revealed that most of the positive results occureed in the 3rd and 4th week i.e. 10 out of 15 (66.67%), 5 positive cultures were obtained in 6th week (33.33%). Conclusion: BACTEC radiometric method is superior to LJ medium for culture of mycobacterium tuberculosis. The average period for BACTEC to detect mycobacteria by culture is 4.5 weeks. Even though smear for AFB is negative BACTEC could detect the mycobacteria by culture