特雷唑来对结核分枝杆菌体外抑菌作用的初步研究

摘要

目的 评价特雷唑来对不同耐药类型的结核分枝杆菌临床分离株的体外抑菌作用,为临床应用提供实验依据.方法 采用微孔板观察法,测定特雷唑来对标准株H37Rv及临床分离的敏感、单耐药、多耐药、耐多药以及广泛耐药各20株(共100株)的 MIC,再测定特雷唑来与7种常用抗结核药物联合使用时,对 H37Rv和 10株 MTB临床分离株(敏感、单耐药、多耐药、耐多药以及广泛耐药各2株)的 MIC,通过计算分级抑菌浓度指数(FICI),观察特雷唑来对结核分枝杆菌的体外抑菌作用以及与其他抗结核药物联合使用时是否有协同作用.结果 94.0% (94/100)的结核分枝杆菌临床分离株可被≤0.5mg/L的特雷唑来抑制生长,特雷唑来对敏感株、 MDR菌株(耐多药和广泛耐药)及非MDR耐药菌株(单耐药和多耐药)的MIC差异无统计学意义(χ2 =0.578,P>0.05).特雷唑来与7种抗结核药物在体外联合使用时对结核标准菌株H37Rv和临床分离株均未表现出相关性. 结论 特雷唑来对结核分枝杆菌,尤其是耐多药和广泛耐药菌株,均有很好的体外抑菌作用,且与细菌对其他抗结核药物是否耐药无关.%Objective To study torezolid on in vitro bacteriostasis of different types of Mycobacterium tuberculosis.Methods The minimal inhibitory concentrations (MICs) of torezolid against sensitive, single-drug resistant (SDR), poly-drug resistant (PDR), multi-drug resistant (MDR), and extensive-drug resistant (XDR) Mycobacterium tuberculosis strains isolated clinically were determined by microplate assay.The interactions between torezolid and isoniazid, rifampicin, streptomycin, ethambutol, kanamycin, ofloxacin and rifabutin were also tested in vitro by fractional inhibitory concentration index (FICI) method.Results 94.0% (94/100) of the Mycobacterium tuberculosis isolates were inhibited by torezolid at concentration ≤0.5 mg/L.There was no statistical difference in the MIC value of sensitive strains, MDR strains and non-MDR strains (χ2=0.578, P>0.05).There was no significant correlation between clinically standard isolates H37Rv and other clinical isolates treated with torezolid and 7 other anti-TB drugs.Conclusion Torezolid shows good in vitro activity against Mycobacterium tuberculosis clinical isolates, especially for MDR and XDR strains, regardless of the drug resistant parameters.