幽门螺杆菌的耐药性及其相关耐药基因的分析

Drug resistance of Helicobacter pylori and related gene mutations

目的了解上海地区幽门螺杆菌(HP)对常用抗菌药物的耐药性,并探究HP耐药相关基因与其耐药性的相关性。方法收集复旦大学附属华东医院和上海同济大学附属同济医院胃黏膜活检样本,分离培养HP,采用E-test法测定其对克拉霉素(CLA)、甲硝唑(MTZ)、阿莫西林(AMX)和左氧氟沙星(LEV)的最小抑菌浓度(MIC),同时采用测序法检测HP中上述4种抗菌药物相关的耐药基因,并分析其与耐药率的相关性。结果从514例胃黏膜活检样本中分离出HP 129株,其中31.4%的菌株对所有4种抗菌药物均敏感,而68.6%的菌株至少对1种抗菌药物耐药。对CLA、MTZ和LEV的耐药率分别为19.8%、57.0%和29.1%,未发现对AMX耐药的菌株;同时发现20株(23.3%)菌株对2种抗菌药物耐药,6株(7.0%)菌株对3种抗菌药物耐药。与CLA、MTZ、AMX和LEV相关的主要耐药基因及其突变位点分别为23S r RNA(A2143G)、rdx A(C148T)、pbp1A(A1777G)和gyr A(C261A/G),其突变频率分别为20.9%、7.0%、9.3%和12.8%。结论上海地区HP对常用抗HP药物的耐药率高,应根据体外药物敏感性试验结果选择敏感的抗菌药物根除HP。相关耐药基因的突变与耐药表型相关。

Objective To study the drug resistance of Helicobacter pylori（HP） to common antibiotics and investigate the correlation of drug resistance and related gene mutations. Methods Gastric mucosa biopsy samples were collected from Huadong Hospital and Tongji Hospital, HP was isolated,and the minimal inhibitory concentrations（MIC） to clarithromycin（CLA）,metronidazole（MTZ）,amoxicillin（AMX） and levofloxacin（LEV）were determined by E-test. Meanwhile,the related gene mutations were determined by gene sequencing,and the correlation of drug resistance and gene mutations was analyzed. Results A total of 129 HP isolates were isolated from 514 cases of gastric mucosa biopsy samples. Among them,68.6% isolates were resistant to 1 kind of antibiotic at least,and the drug resistance rates to CLA,MTZ and LEV were 19.8%,57.0% and 29.1%,respectively,while double- and triple-drug resistance rates were 23.3%（20 isolates）and 7.0%（6 isolates）. The main drug resistance gene mutation loci were 23 S r RNA（A2143G）,rdx A（C148T）,pbp1A（A1777G） and gyr A（C261A/G）,and their mutation rates were 20.9%,7.0%,9.3% and 12.8%. Conclusions The drug resistance rate of HP is high in Shanghai,and drug susceptibility test should become a standard practice during the determination of HP for eradication. Furthermore,specifi c gene mutations are associated with drug resistance.