结核分枝杆菌对PA-824耐药的体外诱导及稳定性研究

发布时间：2018-03-02 13:22

本文选题：分枝杆菌　切入点：结核　出处：《中国抗生素杂志》2017年02期 　论文类型：期刊论文

【摘要】：目的体外诱导并获得结核分枝杆菌(MTB)对PA-824的耐药菌株。方法选取MTB标准株H_(37)Rv,在PA-824浓度二倍递增的含药培养基上进行传代培养,逐步诱导菌株对PA-824耐药,测定多种抗结核药物对PA-824耐药株的最低抑菌浓度(minimal inhibitory concentration,MIC),并对耐药株测序鉴定ddn和fgd1基因的突变情况。将耐药株在无药固体培养基上连续传代培养10代以观察耐药稳定性。结果 H_(37)Rv经逐步诱导后得到5株MTB单克隆,它们对PA-824的MIC值是诱导前8倍以上,且对TBA-354同时发生交叉耐药。测序结果显示fgd1基因未发生突变,但5株均检测到ddn基因突变。耐药株在无药固体培养基上连续传代10代后,MIC值无明显变化。结论通过二倍递增体外诱导可以获得对2种硝基咪唑类(nitroimidazoles)药物均耐药的MTB菌株;MTB对硝基咪唑类药物的耐药可能与ddn基因突变有关;MTB对硝基咪唑类药物的耐药稳定性较强,不易复敏。
[Abstract]:Objective to induce and obtain the drug resistant strains of Mycobacterium tuberculosis to PA-824 in vitro. Methods the standard MTB strain Hast37 Rv.Methods the strains were subcultured on the drug containing medium with double increasing PA-824 concentration, and the drug resistance to PA-824 was induced step by step. The minimal inhibitory concentration of antimicrobial agents against PA-824 resistant strains was determined, and the mutations of ddn and fgd1 genes were identified by sequencing the resistant strains. The resistant strains were cultured on drug-free solid medium for 10 generations to observe drug resistance. Results after induction, 5 MTB monoclonal strains were obtained. Their MIC value to PA-824 was more than 8 times higher than that before induction, and they also had cross resistance to TBA-354. Sequencing showed that the fgd1 gene was not mutated. However, ddn gene mutations were detected in all of the 5 strains. There was no significant change in the ddn values of drug-resistant strains after continuous passage on drug-free solid medium for 10 generations. Conclusion two nitroimidazoles-based nitroimidazoles-resistant drugs can be obtained by twice increasing induction in vitro. The resistance of MTB to nitroimidazoles may be related to the mutation of ddn gene. It is not easy to re-sensitize.
【作者单位】：首都医科大学附属北京胸科医院北京市结核病胸部肿瘤研究所;
【基金】：国家科技新药创制重大专项子课题(No.2015ZX09102007-015) 北京市医院管理局临床医学发展专项经费资助(No.ZYLX201304)
【分类号】：R446.5

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