幽门螺杆菌对6种抗生素的耐药性及其机制的研究

目的了解幽门螺杆菌（Helicobacter pylori，Hp）对6种常用抗生素的耐药状况，探讨耐甲硝唑rdxA基因突变与耐药性的关系。方法分离培养76株Hp，以琼脂稀释法检测Hp对甲硝唑、替硝唑、四环素、克拉（红）霉素、阿莫西林、利福平的最小抑菌浓度（Mininum Inhibitory Concentration，MIC），再用PCR方法扩增甲硝唑耐药相关基因rdxA,DNA测序分析敏感株和耐药株耐药基因的序列与耐药性的关系。免疫印记（westem Blotting）分析耐药基因的表达与耐药性的关系。结果武汉地区人群Hp对甲硝唑、替硝唑、四环素、克拉（红）霉素、阿莫西林、利福平的耐药率分别为67．1％、43．4％、3．9％、11．8％、17．1％和10．5％；甲硝唑耐药基因序列分析表明rdxA基因有插入或点突变；Western Blot显示耐药株和敏感株的rdxA基因的表达有差异。结论幽门螺杆菌对6种抗生素有较高的耐药率，rdxA基因突变导致基因表达水平改变，导致Hp对甲硝唑耐药。

Prevalence and mechanism of antibiotic resistance in helicobacter pylori

[Objective] To investigate the prevalence of helicobacter pylori resistance to six antibiotics and study the relationship between the rdxA gene mutation and the metronidazole resistance. [Methods] 74 H. pylori isolates were collected from the gastric mucosa of patients with peptic ulcer and gastritis. Agar-diffusion method was used for assaying H. pylori susceptibility to metronidazole, nitronidazole, tetracycline, clarithromycin, amoxicillin and rifamipicin. rdxA gene was amplified by PCR. Target DNA were ...