title: Distinct diversity of vacA, cagA, and cagE genes of Helicobacter pylori associated with peptic ulcer in Japan.
abstract: Colonization of the stomach mucosa by Helicobacter pylori is a major cause of acute and chronic gastric pathologies in humans. Several H. pylori virulence genes that may play a role in its pathogenicity have been identified. The most important determinants are vacA and cagA in the cag pathogenicity island (cagPAI) genes. In the present study, to consider the association of molecular genetics between vacA and the cagPAI regarding clinical outcome, we selected H. pylori strains with various genotypes of vacA in Japan and sequenced full-length vacA, cagA, and cagE genes. Sequencing of vacA and cagA genes revealed variable size, whereas the cagE gene was well conserved among strains. Each of the phylogenetic trees based on the deduced amino acid sequences of VacA, CagA, and CagE indicated that all three proteins were divided into two major groups, a Western group and an East Asian group, and the distributions of isolates exhibited similar patterns among the three proteins. The strains with s2 and s1a/m1a vacA genotypes and the Western-type 3' region cagA genotype were classified into the Western group, and the strains with the s1c/m1b vacA genotype and the East Asian-type 3' cagA genotype were included in the East Asian group. In addition, the prevalence of infection with the Western group strain was significantly higher in patients with peptic ulcer (90.0%, 9/10) than in patients with chronic gastritis (22.7%, 5/22) (chi2 = 12.64, P = 0.00057). These data suggest that the molecular genetics of vacA and cagPAI are associated and that the Western group with vacA and cagPAI genes is associated with peptic ulcer disease.
authors.affiliation: Second Department of Internal Medicine, Faculty of Medical Sciences, University of Fukui, Fukui, Japan.
authors.forename: Shiho
authors.initials: S
authors.lastname: Yamazaki
authors.forename: Akiyo
authors.initials: A
authors.lastname: Yamakawa
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Okuda
authors.forename: Masahiro
authors.initials: M
authors.lastname: Ohtani
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Suto
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Ito
authors.forename: Yukinao
authors.initials: Y
authors.lastname: Yamazaki
authors.forename: Yoshihide
authors.initials: Y
authors.lastname: Keida
authors.forename: Hideaki
authors.initials: H
authors.lastname: Higashi
authors.forename: Masanori
authors.initials: M
authors.lastname: Hatakeyama
authors.forename: Takeshi
authors.initials: T
authors.lastname: Azuma
mesh_terms: D000595:Amino Acid Sequence; D000942:Antigens, Bacterial / Q000235:genetics*; D001426:Bacterial Proteins / Q000235:genetics*; D001483:Base Sequence; D014644:Genetic Variation; D016480:Helicobacter pylori / Q000235:genetics*; D006801:Humans; D008969:Molecular Sequence Data; D010437:Peptic Ulcer / Q000382:microbiology*; D010802:Phylogeny
chemical_list: D000942:Antigens, Bacterial; D001426:Bacterial Proteins; C103937:PicB protein, Helicobacter pylori; C074689:VacA protein, Helicobacter pylori; C080866:cagA protein, Helicobacter pylori