手工MGIT系统在基层结核病实验室中检测分枝杆菌的效果评价

目的对手工MGIT液体培养系统（manual mycobacteria growth indicator tube system, M-MGIT）检测分枝杆菌的效果进行评价。方法收集2012年1月至2013年2月北京市朝阳区疾病预防控制中心结核病门诊初诊患者526例，收集首次痰标本526份，分别对同份标本进行罗氏（Lowenstein-Jensen，L-J）固体培养、全自动BACTEC MGIT 960 系统培养（A-MGIT）和M-MGIT系统培养，统计学分析采用χ²检验和t检验，以P<0.05 为差异有统计学意义。结果526份标本中，3种分离培养方法共分离出261株分枝杆菌菌株，检出率为49.6%；M-MGIT法、A-MGIT法和L-J法阳性检出率分别为48.7%（256/526）、49.0%（258/526）和41.3%（217/526）。M-MGIT和A-MGIT培养法检出率均高于L-J培养法，差异有统计学意义（χ²值分别为5.84、6.45，P值均<0.05)，但M-MGIT和A-MGIT培养法检出率差异无统计学意义（χ²=0.02，P>0.05）。M-MGIT法、A-MGIT法和L-J法阳性菌株平均报告时间分别为13d［（13±6）d］、12d［（12±6）d］和24d［（24±9）d］，M-MGIT和A-MGIT法阳性报告时间明显短于L-J法，差异有统计学意义（t值分别为15.84、18.32，P值均<0.05），M-MGIT和A-MGIT之间的差异无统计学意义（t=1.89，P>0.05）。M-MGIT法、A-MGIT法和L-J法污染率分别为4.6%（24/526）、4.9%（26/526）和4.1%（43/1052），差异无统计学意义（χ²=0.64，P>0.05）。结论M-MGIT液体培养系统能快速检测分枝杆菌，检出率高，阳性报告时间短，成本低廉，适合基层结核病实验室应用。

Evaluation on effectiveness of manual MGIT system for detection of Mycobacterium tuberculosis in the primary tuberculosis laboratories

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 （χ2M-MGIT and L-J=5.84,χ2A-MGIT and L-J=6.45, both P〈0.05）, but the difference between M-MGIT and A-MGIT was not significant （χ2M-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 （tM-MGIT and L-J=15.84,tA-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.