长春地区幽门螺杆菌cagA基因及EPIYA基序多态性分析  

Polymorphism of Helicobacter pylori′s cagA gene and EPIYA motifs in Changchun area of China

作　　者：范聪聪[1] 王丽波[2] 江海洋[1] 赵亚楠[1] 武晓琳[1] 赵春燕[1] 

机构地区：[1]吉林大学基础医学院病原生物学系,长春130021 [2]吉林大学第一医院胃肠内科,长春130021

出　　处：《中华微生物学和免疫学杂志》2017年第6期431-437,共7页Chinese Journal of Microbiology and Immunology

基　　金：吉林省科技发展计划资助项目（20150414037GH）

摘　　要：目的 研究长春地区就医人群中幽门螺杆菌（Helicobacter pylori,Hp）毒力基因cagA携带率及其3′端编码CagA蛋白EPIYA基序多态性,并探讨其结构特征的差异与疾病的关系.方法PCR法扩增临床分离株Hp的cagA基因并测序,DNAMAN软件将测序后的核苷酸序列翻译成氨基酸序列,然后利用软件MEGA6.0对测序Hp的cagA基因碱基和蛋白质氨基酸序列进行多重对比分析和构建系统发育进化树.结果 收集298例胃黏膜标本,共分离60株Hp菌株.Hp检出率与性别和年龄无关（P〉0.05）,消化性溃疡（PUD）组的Hp分离率高于非溃疡性消化不良（NUD）组（P〈0.05）.cagA基因阳性率为90%（54/60）.其中成功测序的26株中,23株为东亚型,占88.4%;3株为西方型,占11.6%.东亚型菌株中22株为EPIYA-ABD,1株为EPIYA-ABBD;西方型菌株中,2株为EPIYA-ABC,1株为EPIYA-BC.经构建进化树发现,序列聚类为东亚型群和西方型群两大类,在东亚型群中疾病分布并没有出现明显聚集,西方型群均来自PUD组.4株来自PUD组的Hp发生了氨基酸突变且均发生在EPIYA-B这个片段.结论 本地区分离的Hp cagA基因阳性率为90%,分布与胃肠疾病类型无关;EPIYA分型以毒力强的东亚型EPIYA-ABD 型为主（84.6%,22/26）.EPIYA-B片段氨基酸突变与消化性溃疡密切相关;cagA 3′端DNA序列变化不大,没有明显的地区聚集性.Objective To investigate the distribution of cytotoxin-associated gene A （cagA） of Helicobacter pylori （Hp） and the polymorphism of EPIYA motifs in patients with upper gastrointestinal diseases in Changchun area of China and to evaluate the association between EPYIA motifs patterns and gastrointestinal diseases.Methods Hp strains were isolated from clinical samples.Their cagA gene was analyzed by PCR and sequencing analysis.Nucleotide sequence of cagA gene was translated into amino acid sequence by using DNAMAN software,and then the amino acid sequence was imported into software MEGA6.0 for multiple comparisons and construction of a phylogenetic tree.Results A total of 60 Hp strains were isolated and identified from gastric mucosa specimens collected from 298 patients.Hp infection was not correlated with patient＆#39;s age or sex （P〉0.05）.The isolation rate of Hp in peptic ulcer disease （PUD） group was higher than that in non-peptic ulcer dyspepsia （NUD） group （P〈0.05）.Of the 60 Hp strains,90% （54/60） carried cagA gene.Twenty-three out of 26 successfully sequenced strains （88.4%） were East Asian-type including 22 containing EPIYA-ABD motif and one containing EPIYA-ABBD motif.The other three strains （11.6%） were Western type including two carrying EPIYA-ABC motif and one carrying EPIYA-BC motif.Results of the phylogenetic tree showed that the sequences of cagA gene were clustered into two groups,East Asian-type and Western-type groups.East Asian-type strains caused no disease cluster of statistical significance.All Western-type Hp strains were isolated from patients with peptic ulcer disease （PUD）.Four mutant Hp strains were detected in the PUD group and the amino acid mutations preferentially occurred in the EPIYA-B segment.Conclusion The positive rate of Hp cagA gene is 90% in this region.Its distribution is not related to the type of gastrointestinal diseases.EPIYA-ABD （84.6%,22/26） is the predominant EPIYA motif.The amino acid mutation of EPIYA-B segment is clos

关 键 词：幽门螺杆菌 EPIYA基序 

分 类 号：R378[医药卫生—病原生物学]