Analysis of virulence factors of Helicobacter pylori isolates from Vietnam

幽门螺杆菌在胃癌的发病机制中起着重要的致病作用。本研究的目的是研究越南幽门螺杆菌分离株中被认为是毒力或分子流行病学标记的几个遗传因素。对103株越南幽门螺杆菌的cagA、vacA和cag右端连接基因型进行了PCR和测序分析。在cagA Glu-Pro-Ile-Tyr-Ala （EPIYA）重复区上游区域发现了三种类型的缺失：39-bp缺失型、18-bp缺失型和无缺失型。大多数菌株（77%;80/103）存在18bp缺失。vacA m1基因型在胃癌发病率较高的河内分离株中比在胡志明市分离株中更为常见。

Helicobacter pylori is recognized to play a causative role in the pathogenesis of gastric cancer. The aim of this study was to investigate several genetic factors regarded as virulence or molecular epidemiologic markers in H. pylori isolates from Vietnamese subjects. The cagA, vacA and cag right-end junction genotypes of 103 H. pylori strains from Vietnam were determined by PCR and sequencing. Three types of deletion in the region located upstream of the cagA Glu-Pro-Ile-Tyr-Ala (EPIYA) repeat region were identified : the 39-bp deletion type, the 18-bp deletion type, and the no-deletion type. The majority of strains studied (77% ; 80/103) had the 18-bp deletion. The vacA m1 genotype was significantly more common in strains isolated in Hanoi, where the incidence of gastric cancer is higher, than in strains from Ho Chi Minh.