观察改良的药物敏感性检测法对检出耐药结核分枝杆菌的影响

The Effect of the Improved Minimum Inhibitory Concentration Test on Detection of Drug-resistant Mycobacterium tuberculosis

目的利用经改良的最低抑菌浓度法（IMIC）检测结核分枝杆菌临床分离株对异烟肼、利福平、乙胺丁醇、链霉素和氧氟沙星的药物敏感性，观察其对耐药结核分枝杆菌检出的影响。方法利用改良的最低抑菌浓度法检测135株临床分离株对INH、RFP、EMB、SM及OFLX的敏感性。结果在相同的药物浓度中，与接种1×10 5／ml菌量的试验管相比135株接种1×10 7／ml活菌数的试管中有68．89％的结果与之相同，有311％的结果与之不相同。判断结果由阴性转阳性的标本共有20株，（其中耐RFP的1株、耐INH的3株、耐OFLX的3株、耐EMB的5株以及耐SM的8株）约占135株受试菌株总数的148％。结论利用改良的最低抑菌浓度法可发现潜在的耐药结核病患者，提高耐药菌的检出率。

Objective To develop an improved minimum inhibitory concentration （IMIC） test to detect drug-resistant Mycobactetium tuberculosis clinical isolates. Methods 135 clinical isolates detected the drug susceptibility using traditional proportional method were retested and verified their sensitivity to isoniazid （ INH）, rifampin （RFP）, ethambutol （ EMB）, streptomycin （SM） and ofloxacin （OFLX） by IMIC test .Results In the tubes with same drug concentration, 68.89 % of 135 clinical isolates with 1 × 10 7 / ml bacterium number inoculated got the same results as those with 1 × 10 5 / ml bacterium number inoculated, and 31.1% was inconsistent. 14.8 % （20/135） of the isolates （including 1 RFP-resistant, 3 IN H-resistant, 30FL X-resistant, 5 EMB-resistant and 8 SM-resistant strains） were judged the results from negative to positive. Conclusions The improved minimum inhibitory concentration test could increase positive detectable rate of drog-resistant Mycobacterium tuberculosis, and find more potential drug-resistant TB patients.