新型抗结核活性化合物H37Ra的耐药菌筛选及其菌落表型

ATB-152E和ATB-152J为本实验室前期研究获得的具有良好抗结核活性的两种结构类似的小分子化合物，本文就其作用靶标及耐药机制进行探索。采用含药平板涂板筛选以及平板划线培养法逐步提高化合物浓度，分别筛选出结核分枝杆菌ATB-152E和ATB-152J耐药菌株。选取有代表性的耐药菌株，用微孔法测定结核分枝杆菌的最小抑菌浓度，分别对它们的菌落形态、生物膜形成等表型进行观察并与野生株进行比较。通过不断提高化合物筛选浓度最终筛选到ATB-152E耐药菌株17株、ATB-152J耐药菌株15株，这两种化合物的耐药频率均为10^－7。生长表型结果显示，与野生株结核分枝杆菌相比，ATB-152E耐药菌菌落褶皱变多，ATB-152J耐药菌菌落形态更为扁平，褶皱变少。耐药菌的生物膜形成所需时间与野生株也存在差异，提示活性化合物耐药菌的突变可能导致细菌脂质代谢异常。ATB-152E和ATB-152J耐药菌的获得，为后续深入探索这两种具有良好抗结核活性化合物的作用机制奠定了基础。

Phenotypes of HA37Ra isolates resistant to novel antitubercular compounds

ATB-152E and ATB-152J are structurally similar anti-tuberculosis(anti-TB)chemicals developed by our group in previous research.To study their mechanisms,Mycobacterium tuberculosis(M.tuberculosis)H37Ra strains spontaneously resistant to them were collected and subjected to colony morphology analysis and biofilm formation assay.In total,seventeen ATB-152E resistant strains and fifteen ATB-152J resistant strains were studied.The frequencies of resistance to both compounds were 10-7.Compared with the wild type strains of H37Ra,ATB-152E resistant strains had more folds,while ATB-152J resistant strains presented a flatter pattern with reduced folds.Meanwhile,the time of biofilm formation of resistant strains also differed from the wild type strains,indicating a possible mechanism of inhibition via lipid metabolism.The acquisition of the strains resistant to ATB-152E and ATB-152J could lay a foundation to further study of them.