Bergmann J S, Woods G L
Department of Pathology, University of Texas Medical Branch, Galveston 77550-0740, USA.
Diagn Microbiol Infect Dis. 1997 Jul;28(3):153-6. doi: 10.1016/s0732-8893(97)00006-0.
The reliability of mycobacteria growth indicator tubes (MGIT) for susceptibility testing of Mycobacterium tuberculosis to isoniazid and rifampin was evaluated by comparing MGIT results to those obtained by the radiometric BACTEC TB system. To resolve discrepancies, MGIT and BACTEC TB tests were repeated, and the method of proportion was performed. For the 89 isolates evaluated, there was complete agreement between MGIT and BACTEC results for rifampin: 70 isolates were susceptible, and 19 were resistant. After initial testing of isoniazid, both methods agreed for 85 isolates (95.5%): 72 were susceptible, and 13 were resistant by both methods; 2 were resistant by BACTEC but susceptible by MGIT, and 2 were resistant by MGIT but susceptible by BACTEC. Based on results of discrepant analysis for the latter four isolates, all four were resistant to isoniazid. Thus, MGIT correctly detected susceptibility and resistance to isoniazid for 97.3% and 100% of the isolates, respectively. The mean time to MGIT results was 6.38 +/ 0.11 days (range, 6 to 14 days), compared to a mean of 9.09 +/- 1.90 days (range, 4 to 12 days) for BACTEC (p < .001). MGIT provides a rapid and reliable, nonradiometric alternative to BACTEC for susceptibility testing of M. tuberculosis to isoniazid and rifampin.
通过将分枝杆菌生长指示管（MGIT）检测结核分枝杆菌对异烟肼和利福平药敏的结果与放射性BACTEC TB系统获得的结果进行比较，评估了MGIT的可靠性。为解决差异，重复进行了MGIT和BACTEC TB检测，并采用比例法。对于评估的89株分离菌，MGIT和BACTEC对利福平的检测结果完全一致：70株敏感，19株耐药。异烟肼初次检测后，两种方法对85株分离菌的检测结果一致（95.5%）：两种方法均显示72株敏感，13株耐药；2株BACTEC检测为耐药但MGIT检测为敏感，2株MGIT检测为耐药但BACTEC检测为敏感。基于对后4株分离菌的差异分析结果，这4株均对异烟肼耐药。因此，MGIT分别正确检测出97.3%和100%的分离菌对异烟肼敏感和耐药。MGIT得出结果的平均时间为6.38±0.11天（范围为6至14天），而BACTEC的平均时间为9.09±1.90天（范围为4至12天）（p<0.001）。MGIT为结核分枝杆菌对异烟肼和利福平的药敏检测提供了一种快速、可靠的非放射性替代方法，可替代BACTEC。
