幽门螺杆菌（Hp）是胃、十二指肠疾病的主要致病因子，在不同地区、不同人群感染率和发病率不成正比。广西巴马县是世界著名的长寿之乡，巴马长寿老人普偏存在Hp感染率高，而发病率低的现象，其机理目前尚不清楚。 研究证明，Hp菌株存在多态性，导致不同地区不同人群Hp的毒力各不相同。Hp的毒力主要与细胞毒素相关基因(CagA )、空泡毒素基因(VacA)等有关。 基于Hp基因多态性，本项目在前期研究广西人感染Hp耐药机制和基因型的基础上，采集巴马县人群和滇黔桂三省交界地区人群的胃粘膜或唾液，分离培养Hp，采用DNA 测序、RAPD等技术分析菌株基因多态性、基因型；RT-PCR等技术检测菌株毒力因子，筛选高、低毒力菌株及其在人胃内生长环境，体外模拟生长环境诱导菌株生长，检测毒力因子CagA、VacA等基因的变化，探讨Hp菌株在地域差异中的基因特点和诱导菌株毒力减弱的方法，为防治Hp提供重要实验依据。

Helicobacter pylori (Hp) are the main pathogenic factors of various stomach and duodenum diseases. The infection rate and incidence of different populations in different regions is not proportional. Bama County of Guangxi is a world famous longevity, where exist a phenomenon of high infection arte of Hp, while low incidence, and the mechanism remain unclear. Studies have shown that Hp exist polymorphism, leading to different populations in different regions vary in virulence of Hp, and the virulence of Hp was mostly related to cytotoxin associated gene (CagA), vacuolating cytotoxin gene (VacA) and others. Based on our early achievements, study on the mechanism and genotype of Hp strain drug resistance in Guangxi people, this study intends to analasis the gene polymorphism and genotype of hp by collecting the gastric mucosa and saliva of people in Bama County and Yunnan Guizhou Guangxi border provinces,isolating and cultrueing hp stains, DNA sequencing and RAPD methods. Techniques such as RT-PCR was using to test the virulence factors, screen out high and low toxic strains, Hp growth environment in the stomach and in vitro, the changes cytotoxin associated gene (CagA) and vacuolating cytotoxin gene (VacA) were also tested, further clarifies the genetic characteristics of Hp in regional differences and methods inducing virulence attenuated, thereby offering the valuable experimental evidences for the prevention and treatment of Hp.