Abstract: Objective  To evaluate the effectiveness of manual mycobacteria growth indicator tube (M-MGIT) system for rapid detection of Mycobacterium tuberculosis. Methods  Five hundred and twenty-six sputa of newly diagnosed tuberculosis patients were collected from January 2012 to February 2013 in the tuberculosis clinic of Chaoyang District Center for Disease Control and Prevention. All the sputa were cultured by Lowenstein-Jensen (L-J) medium, M-MGIT system and automated BACTEC MGIT 960 (A-MGIT) system. Theχ² test and t test were used to analyze statistically the result, and if P<0.05, the results had the significant difference.  Results  Of the 526 sputa specimens, 261 (49.6%) were isolated as Mycobacterium tuberculosis strains. The positive culture rates of the M-MGIT, A-MGIT and L-J method were 48.7% (256/526), 49.0％(258/526) and 41.3% (217/526) respectively. The culture positive rates of M-MGIT and A-MGIT both were significantly higher than that of L-J method (χ²_{M-MGIT and L-J}=5.84，χ²_{A-MGIT and L-J}=6.45, both P<0.05), but the difference between M-MGIT and A-MGIT was not significant (χ²_{M-MGIT and A-MGIT}=0.02, P>0.05). The mean times of detection with M-MGIT system, A-MGIT system and L-J method were 13 (13±6) days, 12 (12±6) days and 24 (24±9) days，respectively. Comparing the mean detection times of M-MGIT with L-J method and A-MGIT with L-J method，both differences were statistically significant (t_{M-MGIT and L-J}=15.84，t_{A-MGIT and L-J}=18.32，P<0.05). Comparing the mean detection time of M-MGIT system with A-MGIT system, the difference had not statistical significance (t=1.89, P>0.05). The rates of contamination were 4.6% (24/526) with the M-MGIT system, 4.9% (26/526) with A-MGIT system and 4.1% (43/1052) with L-J medium, the difference was not statistically significant (χ²=0.64，P>0.05).  Conclusion  M-MGIT system is a rapid detection method of Mycobacterium tuberculosis with a higher positive detection rate, do not need expensive equipment, is suitable for the routine diagnosis in the primary tuberculosis laboratories.

Key words: Mycobacterium tuberculosis, Bacteriological techniques