显微镜观察药物敏感性试验检测结核杆菌的耐药性

Detection on drug resistance of Mycobacterium tuberculosis by microscopic observation drug susceptibility

目的探讨显微镜观察药物敏感性试验（MODS）同时陕速检测结核杆菌对4种一线抗结核药物耐药性的效果。方法用24孔细胞培养板进行结核分枝杆菌（MTB）液体药敏检测，并对最佳检测条件进行探讨；将建立的MODS技术用于测定66株MTB临床分离株对链霉素、异烟肼、利福平、乙胺丁醇的耐药性，并与传统罗氏药敏结果进行比较，对两法检测结果不符的菌株进行最低抑菌浓度（MIC）测定。结果MODS检测链霉素、异烟肼、利福平、乙胺丁醇药敏结果与罗氏药敏结果符合率分别为97．0％、90．9％、95．5％、86．4％。如以传统罗氏药敏结果为判断标准，则MODS检测链霉素的敏感度为96．0％、特异度为97．6％、阳性和阴性预测值（PPV、NPV）及准确性分别为96．0％、97．6％和97．O％；检测异烟肼、利福平和乙胺丁醇的敏感度、特异度、PPV、NPV及准确性分别为100％、85．4％、81．O％、100％、90．9％；96．2％、95．0％、92．6％、97．4％、95．5％和73．7％、91．5％、77．8％、89．6％、86．4％。共有16株菌的20个药敏结果MODS与传统罗氏药敏结果不符，MIC检测结果有14株16个药敏结果与MODS结果一致，4株菌4个药敏结果与罗氏药敏结果一致。结论MODS同时检测链霉素、异烟肼、利福平、乙胺丁醇药敏结果具有快速、操作简便、价廉等优点，与传统罗氏药敏结果有较高的符合率，可作为MTB耐药性的快速检测方法之一。

Objective To evaluate the effects of microscopic observation drug susceptibility （MODS） in detecting susceptibility of Mycobacterium tuberculosis （ MTB ） onto four first line anti-tuberculosis drugs. Method The 24-hole cell culture plates were used to test drug susceptibility of MTB on liquid medium, and the best detecting condition of MODS assay was probed; 66 clinical isolates susceptibility to streptomycin （S） , isoniazid （H） , rifampin （R） and ethambatal （ E ） were evaluated by using MODS assay and Lowenstein-Jensen（L-J） ,thereafter,all the inconcordance of isolates between MODS and L-J were tested for the minimal inhibitory concentrations （ MIC ）. Results Concordance rate of the susceptibility to S, H, R and E in 66 clinical isolates detected by MODS and L-J was 97. 0% ,90. 9% ,95. 5% and 86.4% respectively. If the results obtained by L-J were taken as a golden standard, the sensitivity, specificity, positive and negative predictive value （PPV and NPV ） as well as accuracy of susceptibility test to S detected by MODS was 96. 0% ,97.6% ,96. 0% ,97.6% and 97.0% ; 100% ,85.4% ,81.0%, 100% and 90. 9% to H; 96. 2%, 95% ,92. 6% ,97.4% and 95.5% to R; 73.7% ,91.5% ,77.8% ,89.6% and 86.4% to E. There were 20 inconsistent results of 16 isolates by comparing MODS with L-J,and MIC yielded 16 results of those 14 isolates showing identical results with those of the MODS, while 4 results of other 4 isolates identical with L- J. Condosion MODS method simultaneously provides drug susceptibility to S, H, R and E. MODS might be one of the rapid tools to diagnosing multidrug-resistant tuberculosis as it is rapid, simple, inexpensive and has high concordance with L-J drug susceptibility test.