三种喹诺酮类药物抗结核分支杆菌最低抑菌浓度分布状况研究

目的　探索三种喹诺酮类药物抗结核分支杆菌的抑菌浓度，分析三种药物的最低抑菌浓度(minimal inhibitory concentration，MIC)分布。方法 采用试管等倍稀释法测药物MIC。结果 未用喹诺酮类药物的结核菌株21株中20株 (95.2%)的MIC分布与H₃₇Rv的MIC值相近。应用喹诺酮类药物于4周的结核菌株15株中13株 (86.7%)MIC分布与未用药组MIC分布相同，用喹诺酮类药物4周以上的结核菌株16株中15株 (93.7%)的MIC的分布与未用药组的MIC分布相比，增高的趋势明显。结论 长时间应用喹诺酮类药物可能会引起MIC的增高而影响临床疗效。

Study on MICs' distribution of three kinds of fluoroquinlone againstMycobacterium tuberculosis

Objective To explore the MICs' distribution of ofloxacin,levofloxacin and ciprofloxacin against clinical isolate of Mycobacterium tuberculosis in vitro strains.Methods The MICs of these drugs were determined by equivalent dilution method.Results Of 21 clinical isolates of M.tuberculosis not previously exposed,and of 15 clinical isolates previously exposed within 4 weeks to these drugs,the MICs of 20 (95.2%) and 13(86.7%) respectively were closed to that of Mycobacterium tuberculosis H 37 Rv's,of 16 isolates of M.tuberculosis previously exposed beyond 4 weeks,MICs of 15 isolates (93.7%) were higher than that of H 37 Rv.Conclusion If the three drugs were treated patients with tuberculosis for a long time,the MICs of M.Tuberculosis of these drugs might be increased.