结核分枝杆菌临床分离株药敏结果与耐药程度的关联分析

目的 探讨结核分枝杆菌临床分离株对12种抗结核药物的MIC值及其药敏检测结果 与耐药程度的关联规律,从而为临床制定治疗方案提供借鉴依据.方法 采用液体培养基联合MTT技术进行抗结核药物的MIC检测.对上海市肺科医院2009年1-6月间的163株结核分枝杆菌临床分离株进行RFP、INH、SM、EMB、OFLX、LVFX、MOX、AMK、CPM、PTA、CLA和PAIN的MIC检测和Bactec MGIT快速培养仪药敏检测,并进行MIC与耐药程度的关联性分析.结果 67%(42/62)的SM耐药株MIC≥16 μg/ml,63%(51/81)的INH耐药株MIC≥8 μg/ml,77%(50/65)的RFP耐药株MIC≥8 μg/ml,20%(12/60)的EMB耐药株MIC≥4 μg/ml;43%(25/58)的OFLX耐药株MIC≥8 μg/ml;41%(15/37)的AMK耐药菌株MIC≥16 μg/ml,41%(12/29)的CPM耐药菌株MIC≥4 μg/ml.OFLX耐药株的3个氟喹诺酮类药物的MIC(OFLX、LVFX和MOX的MIC分别为2～128、1～32和0.0625～1 μg/ml)差异有统计学意义(F=16.874,P<0.01);SM、INH、RFP、EMB、OFLX、AMK和CPM在任6种及7种药物同时耐药株中的MIC值(分别为0.5～128、2～64、0.25～128、1～32、1～64、0.5～128和1～128μg/ml)明显高于任1种及2种药物耐药菌株的MIC值(MIC值分别为0.25～128、0.0625～64、0.25～32、0.25～2、0.125～2、0.5～4和1～4 μg/ml,F值分别为20.066、40.499、47.197、70.373、91.432、41.840和21.547,P均<0.05);SM、INH、RFP、EMB在4种药物同时耐药菌株中MIC值(分别为1～128、2～64、0.25～128和1～32μg/ml)显著高于任1种及2种药物耐药株(MIC值分别为0.25～128、0.0625～64、0.25～64和0.25～2 μg/ml,F值分别为26.242、23.563、31.541和64.469,P均<0.05);RFP在MDR酶株的MIC值(2～64 μg/ml)显著高于非MDR的耐药菌株的MIC值(0.25 μg/ml,F=5.613,P<0.05).结论 本研究揭示了常用的12种抗结核药物的耐药程度与常规药敏检测结果 之间的关联规律,为临床医生根据常规药敏结果 制定更加有效的抗结核治疗方案提供重要的借鉴.

Correlation between the results of drug susceptibilities and the extent of drug-resistances in Mycobacterium tuberculosis clinical isolates

Objective To investigate correlation between the results of drug susceptibility and the extent of drug-resistances in Mycobacterium tuberculosis clinical isolates. Methods Liquid culture and MTT test were used. Twelve anti-TB drug MICs and drug susceptibility testing of the 163 MTB strains from random clinical isolates were detected, which including RFP, INH, SM, EBM, OFLX, LVFX, MOX, AMK,CPM, PTA, CLA and PAIN. Results There are 67% (42/62) Mycobacterium tuberculosis strains resistant to SM, 63% (51/81) Mycobacterium tuberculosis strains resistant to INH, 77% (50/65) Mycobacterium tuberculosis strains resistant to RFP, 41% ( 15/37 ) Mycobacterium tuberculosis strains resistant to AMK,41% (12/29) Mycobacterium tuberculosis strains resistant to CPM, 20% (12/60) Mycobacterium tuberculosis strains resistant to EMB and 43% (25/58) Mycobacterium tuberculosis strains resistant to OFLX which MICs were equal to or more than 16 μg/ml, 8 μg/ml, 8 μg/ml, 16 μg/ml and 4 μg/ml, 4 μg/ml and 8 μg/ml,respectively. There were significant differences in the MICs of OFLX, LVFX and MOX in OFLX resistant strains (2-128, 1-32 and 0.0625-1 μg/ml, respectively) by ANOVA ( F = 16.874, P ＜ 0.001 ). The MICs of SM, INH, RFP, EMB, OFLX, AMK and CPM in isolates resistant to six or seven drugs (0.5-128,2-64,0.25-128,1-32,1-64,0.5-128 and 1-128 μg/ml,respectively) were higher than those (0.25-128,0.0625-64,0.25-32,0.25-2,0.125-2,0.5-4 and 1-4 μg/ml,respectively) in isolates resistant to one or two drugs (F=20.066, 40.499, 47. 197, 70.373, 91.432, 41.840 and 21.547, respectively, P ＜0.05). The MICs of SM, INH, RFP and EMB in isolates resistant to four drugs (1-128,2-64,0.25-128 and 1-32 μg/ml,respectively ) were higher than those ( 0.25-128,0.0625-64, 0.25-64 and 0.25-2 μg/ml,respectively) in isolates resistant to one or two drugs (F = 26.242, 23.563, 31.541 and 64.469,respectively, P ＜0.05).The MICs of RFP in MDR isolates (2-64 μg/ml) were higher than those (0. 25 μg/ml) in other resistant isolate except M DR isolates (F = 5.613, P <0.05). Conclusions The study shows that there are associations between the results of routine drug susceptibility testing and the resistant extent of anti-TB drugs. This could help doctors select more effective anti-TB regimen for TB patients according to the correlations.