显微镜观察药物敏感性技术快速检测结核分枝杆菌研究

Evaluation of Microscopic Observation Drug Susceptibility Assay in Detection of Mycobacterium tuberculosis

目的建立显微镜观察药物敏感性(MODS)技术并应用其进行结核分枝杆菌(MTB)的快速检测。方法用24孔细胞培养板液体培养方法建立MODS技术,并对其方法学进行探讨和用于MTB及非结核分枝杆菌(NMT)的检测,同时与传统罗氏培养和鉴定法结果进行比较。结果菌液浓度为3×103CFU/ml时运用MODS技术检测判读结果时间为7 d;4种NMT标准株(草分枝杆菌、堪萨斯分枝杆菌、龟分枝杆菌、海分枝杆菌)在液体培养基中观察到呈索状结构生长,镜下难于和MTB形成的特征索状结构区分;以对硝基苯甲酸800μg/ml、噻吩-2-羧酸肼2.5μg/ml为检测条件,能提高检测的正确率;临床分离株检测结果表明,该法与传统罗氏培养和鉴定法结果符合率为97.0%,如以罗氏培养、鉴定法为判断标准,则MODS检测MTB的敏感性、特异性、阳性预测值、阴性预测值、正确性分别为95.7%,100.0%、100.0%、99.9%、97.0%。结论MODS技术检测MTB与传统罗氏培养和鉴定法结果符合率较高,且具有快速、操作简便、价廉等优点,可作为MTB快速检测的新方法之一。

OBJECTIVE To set up and evaluate the microscopic observation drug susceptibility assay（MODS）technology and use it to detect rapidly Mycobacterium tuberculosis（MTB）.METHODS The 24-hole cell culture plate method of liquid culture were used to set up MODS technology.The MODS technology was used to detect MTB and non-M.tuberculosis（NMT）isolates comparing with Lowenstein-Jensen（L-J） method.RESULTS When bacterial concentration was 3×10^3 CFU/ml,the time of reading test-result was the seventh day by MODS;four kinds of NMT（M.phlei,M.kansasii,M.chelonaeand M.marinum） in the liquid medium in the observation was similar to the growth of cording,it was difficult to distinct from the cording of MTB in the liquid medium;When using the 4-Nitro-benzoic acid 800 μg/ml,thiophene-2-carboxylic acid hydrazine 2.5 μg/ml for testing conditions,the correct diagnosis can be improved;the test results of clinical isolates by MODS were highly concordance rate with the results of L-J.If the results of L-J was the golden standard,the sensitivity,specificity,positive and negative predictive value as well as accuracy by MODS was 95.7%,100%,100%,99.9% and 97% respectively.CONCLUSIONS The results of MODS in detection of MTB are highly concordance wih the results of L-J method;MODS assay can be used for rapid detection of tuberculosis,with a rapid,simple,inexpensive,and other advantages.