Sensitivity and Specificity of Mycobacteria Tuberculosis Culture Using Liquid Media on Bronchoalveolar Lavage From Negative Acid Fast Bacili Pulmonary Tuberculosis Patients


Setiarsih HS, Wiyono WH, Burhan E, Soemanto RK, Widyahening IS. J Respir Indones. 2012;32(2):89-99.


Introduction: Diagnostic tuberculosis using acid fast bacilli (AFB) microscopy and conventional Lowenstein Jensen (LJ) culture remain the cornerstone but the sensitivity of these traditional methods is quite low, especially in the samples containing small number of organism. There is a need for rapid, sensitive and accurate detection of these organisms in clinical specimens to hasten the administration of appropriate antimycobacterial therapy and prevent the spread of infection in the community. Sputum smear-negative pulmonary tuberculosis (SSN-PTB) is a common problem faced by clinicians. Performing fiber optic bronchoscopy (FOB) and subjecting the bronchoalveolar lavage (BAL) material to diagnostic methods of smear and mycobacterial culture appears to be helpful in the diagnosis of SSN-PTB.
Methods: Cross sectional study and diagnostic test, data collected from sputum smear-negative pulmonary tuberculosis patients between April 2010 until Juli 2010. The fiber optic bronchoscopy was performed to get BAL material, examined smear and mycobacterial culture using liquid media (Mycobacterial growth indicator tube/BACTEC MGIT 960 automated) and solid media (LJ). The BACTEC MGIT 960® and LJ cultures will compared each other in growing M. tuberculosis and the time for detecting M. tuberculosis earlier.
Results: There were 33 patients (13 female, 20 male). The mean of age was 33.55 years old. The positive AFB smear BAL was 7 patients (21.2%), the positive culture by MGIT 960® medium was 21 patients (63.64%), the mean time to detection of M. tuberculosis in smear positive was 16 days for MGIT 960 and in smear negative specimens it was 19.07 days. The positive culture of LJ medium was 15 patients (45.45%), the mean time to detect of M. tuberculosis in smear positive was 32 days for LJ. and in smear negative specimens it was 39.78 days. The sensitivity of BACTEC MGIT 960® is 100 % and specificity is 66.67 %.
Conclusion: Detection of M tuberculosis using liquid media (BACTEC MGIT 960®) performed on BAL samples in AFB negative pulmonary TB patients yielded has shorter duration compared with conventional Lowenstein Jenssen solid media and high sensitivity.

Key Word: sputum smear-negative pulmonary tuberculosis, Mycobacteria Growth Indicator Tube (MGIT), bronchoalveolar lavage.

Click for detailed article

Leave a Comment