Tuberculosis (TB), which is caused by infection with Mycobacterium tuberculosis, is responsible for about one third of preventable deaths worldwide. Accurate and rapid diagnosis of TB is essential for controlling the spread of the disease.
The aim of this study was to evaluate the Mycobacteria Growth Indicator Tube 690 [(MGIT 960), (M690)] which is a fully automated, non-invasive system for growth and detection of Mycobacteria, andLowenstein-Jensen(LJ)media for the recovery of Mycobacterium tuberculosis from sputum samples.
Methods:Out of 67 samples processed, 60 isolates (89.5%) were recovered by M690 media while, 50 isolates (74.6%) were obtained by LJ. M960 as a single system detected 11 (16.4%) isolates more than LJ media. While LJmedia detected 2 (2.9%) isolates (revealed no growth in M960). In total, out of these 67 specimens, 48 (71.6%) isolates were positive by all methods (Z-N smear, culture on both LJ and MGIT broth). And 48 isolates also were obtained by the combined use of both culture methods. Average detection time of M960 andLJmedia was 14.6 days (2-38) and 30.6 days (7-58) respectively. The contamination rates in our study were 2.9% for M960 and 1.49% for LJmedia.
Conclusion:Comparable to LJ, M960 system is a rapid and efficient method for diagnosis of pulmonary TB, but for maximum recovery of mycobacteria, a combination of both M960 and LJmedia should be used.