幽门螺杆菌对甲硝唑的耐药性分析

摘要

目的 探讨幽门螺杆菌(Helicobacter pylori,Hp)甲硝唑耐药菌株相关基因的突变与耐药性的关系.方法 收集临床60例有胃部不适患者的胃活检组织,微需氧培养得到Hp菌株.E-Test法检测Hp对甲硝唑的最低抑菌浓度(MIC),PCR扩增rdxA、frxA、fdxB,并对该基因进行测序,对耐药株的rdxA、frxA、fdxB的基因序列与标准株Hp26695相应序列进行同源性分析.结果 60例病人胃粘膜标本成功分离出11株Hp耐甲硝唑株(MIC均≥256 μg/mL).11株临床株和1株国际标准测序株(Hp26695)均扩增出rdxA、frxA、和fdxB;基因rdxA、fdxB和frxA突变有一定的规律性,除了存在共同突变外,还存在随机位点散在突变.结论 Hp对甲硝唑耐药性与rdxA、fdxB和frxA基因突变相关.%To investigate the relationship between the related gene mutation and the resistance in Helicobacter pylori (H. pylori) to metronidazole (Mtz), all the H. pylori strains were isolated from the gastric mucosal biopsies of 60 patients, and incubated in microaerophilic culture. Minimal inhibitory concentration (MIC) of H pylri to Mtz was determined by E-test method. The gene fragments of rdxA.frxA and fdxB were amplified by PCR and then sequenced. Finally polymorphism analy-sis was performed in rdxA, frxA and fdxB from those strains resistant to Mtz and standard strains H. pylori 26695. It was found that there were 11 Mtz-resistant H. pylori strains(MIC≥256 μg/mL) isolated from 60 spesiments of gastric musosa. The gene fragments of rdxA, frxA and fdxB were amplified successfully between 11 stains resistant to Mtz and the standard strains H. pylori 26695. Compared with the standard strains H. pylori 26695, these gene mutation reprsented regularfy that there were not only common mutable points, but also some other random mutable points dispersedly. The results imply that H. pylori's resistance to Mtz is relevant to mutation of rdxA, fdxB and frxA.