海南省39株幽门螺杆菌的耐药性及毒力基因特征

Antibiotic resistance and virulence gene characteristic of 39 strains of Helicobacter pylori in Hainan

目的了解海南省幽门螺杆菌(Hp)耐药性及其毒力基因vacA、cagA和iceA基因型特征。方法对146例上消化道症状疾病患者进行胃镜检查,取胃黏膜组织进行Hp的分离和培养,对Hp进行药敏检测;通过聚合酶链式反应(PCR)对毒力基因cagA、vacA和iceA进行检测和分型,cagA测序进行聚类分析、并构建系统进化树;使用Fisher确切概率法分析各型毒力基因和患者疾病发生的相关性。结果共培养出39株Hp,对阿莫西林和克拉霉素的耐药率分别为2.6%和48.7%;39株均为vacA^(+)菌株,iceA 1型26株、2型13株;33株为cagA^(+)菌株,其中5株为西方型(EPIYA-ABC型),28株为东亚型(EPIYA-ABD型);cagA^(+)和vacA^(+)菌株与胃和十二指肠疾病有显著的相关性(P<0.05),iceA则无显著性差异(P>0.05)。结论海南省胃和十二指肠Hp患者中Hp毒力基因多样化,vacA s1am2/cagA^(+)基因型在消化性溃疡患者中占优势,不同毒力基因型对胃和十二指肠疾病的发生具有明显的差别,阿莫西林可作为该地区根除Hp首选抗生素。

Objective To explore the association between resistance of Helicobacter pylori(Hp)and the distribution of virulence genes vacuolating cytotoxin A(vacA),cytotoxin-associated gene A(cagA),and induced by contact with epithelium gene A(iceA)genotypes with gastric disease occurrence in Hainan province,China.Methods All the 146 patients with diseases of upper digestive tract were enrolled for rapid urea breath test(RUT)and gastroscopy test.Hp was separated and cultured for drug susceptibility test.Virulence genes of cagA,vacA,and iceA were detected and typed.The cagA sequencing was performed to differentiate Western strains from East Asian strains,and the phylogenetic tree was established.Fisher exact probability method was used to analyze the correlation between virulence genes and disease occurrence.Results A total of 39 Hp strains were successfully cultured.Their resistance rates to amoxicillin and clarithromycin were 2.6%and 48.7%,respectively.All the 39 strains were vacA^(+),with 26 Type 1 strains and 13 Type 2 strains.There were 33 cagA^(+)strains,including 5 strains of Western type(EPIYA-ABC type)and 28 strains of East Asian type(EPIYA-ABD type).The cagA^(+)and vacA^(+)strains were significantly associated with gastric and duodenal diseases(P<0.05),while iceA showed no significant association with the detection rate of gastric and duodenal diseases(P>0.05).Conclusion Amoxicillin is the preferred antibiotics for eradicating Hp in Hainan province.Hp virulence genes are diversified in patients with gastric and duodenal diseases in Hainan province,the vacA s1am2/cagA^(+)genotype is especially dominant in patients with peptic ulcer in Hainan province,and different virulence genes have obvious differences in the occurrence of gastric and duodenal diseases.