利福布汀对非结核分枝杆菌抗菌活性的初步探讨

目的观察利福布汀对非结核分枝杆菌的抗菌活性,探讨利福布汀对常见致病性非结核分枝杆菌的实验室耐药临界浓度,为临床合理应用利福布汀治疗非结核分枝杆菌病提供依据。方法采用液体培养基倍比稀释法检测利福布汀和利福平对50株非结核分枝杆菌（NTM）的最低抑菌浓度（MIC）。结果 （1）对34株鸟分枝杆菌复合群的MIC：76.5%（26/34）菌株的利福平MIC≥1μg/ml,而利福布汀MIC有85.3%（29/34）分布在0.125~2μg/ml,其中在0.125~1μg/ml的有25株;（2）6株偶然分枝杆菌的MIC：利福平的MIC多〉8μg/ml,而利福布汀的MIC为1~8μg/ml;（3）5株脓肿分枝杆菌的MIC：利福平的MIC〉64μg/ml,利福布汀的MIC为2~32μg/ml;（4）其他非结核分枝杆菌：利福平和利福布汀对蟾蜍分枝杆菌、堪萨斯分枝杆菌、戈登分枝杆菌、瘰疠分枝杆菌、不产色分枝杆菌的MIC分别为〉64μg/mlvs1μg/ml、2μg/mlvs0.25μg/ml、8μg/mlvs1μg/ml、4μg/mlvs1μg/ml、4μg/mlvs1μg/ml。结论初步得出利福布汀对常见致病性非结核分枝杆菌的实验室耐药临界浓度为4~8μg/ml。利福布汀对鸟分枝杆菌复合群、勘萨斯分枝杆菌的抗菌活性优于利福平;蟾蜍分枝杆菌、戈登分枝杆菌、瘰疠分枝杆菌、不产色分枝杆菌对利福平体外MIC值达到临床耐药浓度时,利福布汀对其仍有体外抗菌活性。

Study on activity of rifabutin against non-tuberculous mycobacteria

Objective To study the bactericidal effect of rifabutin against non-tuberculosis Mycobacterium and determine the critical concentration of rifabutin to provide laboratory data for rifabutin in treatment of non-tuberculosis Mycobacterium.Methods The minimal inhibitory concentrations（MICs）of rifampin and rifabutin to 50 clinical non-tuberculosis Mycobacterium isolates were detected through Middlebrook 7H9 media.Results（1）The MICs of rifampin against Mycobacterium aviumcomplex（MAC）were ≥1 μg/ml for 76.5%（26/34）strains,while the MICs of rifabutin ranged from 0.125 μg/ml to 2 μg/ml for 85.3%（29/34）strains.（2）The MICs of rifampin and rifabutin against 6 strains of Mycobacterium fortuitum were mainly 8 μg/ml and 1μg/ml to 8 μg/ml,respectively.（3）The MICs of rifampin and rifabutin against Mycobacterium abscessus were 64 μg/ml and 2 μg/ml to 32 μg/ml,respectively.（4）The MIC of rifampin and rifabutin against Mycobacterium xenopi,Mycobacterium gordona,Mycobacterium kansasii,Mycobacterium scrofulaceum,non-photochromogens were 64 μg/ml vs 1 μg/ml、2 μg/ml vs 0.25 μg/ml、8 μg/ml vs 1 μg/ml、4 μg/ml vs 1 μg/ml、4 μg/ml vs 1 μg/ml,respectively.Conclusions Rifabutin is more effective than rifampin in vitro against MAC and Mycobacterium kansasii.Some rifampin resistant strains still show susceptibility to rifabutin,which suggests rifabutin may be effective in treatment of rifampin resistant non-tuberculous mycobacterial.