手工判读MGIT法检测分枝杆菌的效果评价

Evaluation of effectiveness of manual MGIT system for detection of Mycobacterium

目的应用手工荧光判读仪对MGIT液体培养基进行快速检测分枝杆菌的效果评价。方法收集2011年3月至2011年4月杭州市红十字会医院临床诊断为结核病的患者临床标本230份,其中涂片法抗酸染色阳性标本57份,阴性标本173份。分别对同份标本做L-J固体和MGIT液体培养法分离培养效果比较,结果统计学分析采用χ2检验和非参数检验(Z),P值<0.05差异有统计学意义。结果 230份标本中,两种分离培养方法共分离出90株分枝杆菌菌株,检出率为39.1%(90/230);其中MGIT液体培养检出率为34.3%(79/230),L-J培养检出率为27.4%(63/230)。在173份抗酸染色阴性标本中,用液体培养和L-J培养分离培养检出率分别为19.1%(33/173)、11.0%(19/173)。上述两组数据经统计学分析,培养检出率差异有统计学意义(P<0.05)。MGIT液体培养法阳性报告时间中位数为13天;L-J培养法阳性报告时间中位数为21天,差异有统计学意义(Z=3.293,P<0.001)。抗酸涂阳样本MGIT液体培养法阳性报告时间比抗酸涂阴标本提早7天。结论手工MGIT液体培养法能快速检测分枝杆菌,检出率高,适合基层实验室推广应用。

Objective To evaluate the value of MGIT liquid medium with manual fluorescence instrument for rapid detection of Mycobacterium. Methods During March-April 2011,230 specimens from newly diagnosed and re-treated TB patients were collected in Hangzhou Red Cross Hospital, in which 57 specimens were positive and 173 were negative by acid-fast stain （AFB） microscopic examination. Mycobacterium in the same specimens was isolated with L-J and MGIT liquid medium respectively. The data were analyzed statistically with X2 and Z test, the results were statistical significant （P 〈 0. 05）. Results Among 230 sputum specimens, 90 Mycobacterium stains （39. 1% ） were cultivated by both MGIT and L-J medium, 79 （34. 3% ） by MGIT and 63 （27.4%） by L-J medium, respectively. Of 173 AFB smear-negative specimens, 33 （19. 1% ） were cultured by MGIT, while 19 （11.0%） were cultured by L-J medium. The positive rate of culture with MGIT was significantly higher than that with L-J medium （ P 〈 0. 05 ）. The mean time of Mycobacterium detection with MGIT was 13 days, while that with L-J medium was 21 days, the difference was significant （ Z = 3. 293, P 〈0. 001 ）. On the average time of obtaining positive results, it was 7 days earlier for AFB smear-positive samples than for AFB smear-negative samples with MGIT. Conclusion Manual MIGT liquid medium method is rapid in detecting Mycobacterium with high positive rate, which is suitable for the routine diagnosis in laboratories at grass roots level.