日本の一地域におけるHelicobacter pyloriのcagA遺伝子とvacA遺伝子genotypeの胃癌病原性指標としての検討

抄録

The presence of the cagA gene and the genotype of the vacA gene have been associated with the virulence of Helicobacter pylori. The aim of this study was to characterize the genotypes of these genes in Japanese H. pylori isolates. H. pylori strains isolated from 50 patients with gastric cancer and 50 subjects who were diagnosed as atrophic gastritis or normal. DNA was extracted from each strain, to determine the presence of the cagA gene and the genotype of the vacA gene using polymelase chain reaction. The cagA gene was positive in all strains isolated from patients with gastric cancer and 94% of strains isolated from control subjects. The vacAgenotype was sl/ml in all strains. These results suggest that most H. pylori strains are the virulent genotype in Japan. While the high frequency of strain with the virulent genotype might play a role in the extended atrophic gastritis and the increased incidence of gastric cancer in Japan, it precludes its use as a phenotypic marker of the virulence of Japanese H pylori strains.