摘要
INTRODUCTION Helicobacter pylori(H.pylori)infection is one ofthe main pathogens of chronic gastritis and duodenalulcer(DU),and it may be considered as a riskfactor in the incidence of gastric cancer.H.pylori infection may lead to the anomaly of gastricepithelial cell proliferation which is closely relatedto the development of gastric cancer.Vacuolatingcytotoxin(VacA)is an important virulence andvacA subtype determines the toxic activity.According to its signal sequence,it can be groupedinto type sla,slb,slc and s2.Strains harboringvacAsla are more closely related with digestivediseases and may be the strains with high toxicity.The effect of H.pylori infection on
