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Distinct Diversity of vacA , cagA , and cagE Genes of Helicobacter pylori Associated with Peptic Ulcer in Japan

2005; American Society for Microbiology; Volume: 43; Issue: 8 Linguagem: Inglês

10.1128/jcm.43.8.3906-3916.2005

1098-660X

Shiho Yamazaki, Akiyo Yamakawa, Tomoyuki Okuda, Masahiro Ohtani, Hiroyuki Suto, Yoshiyuki Ito, Yukinao Yamazaki, Yoshihide Keida, Hideaki Higashi, Masanori Hatakeyama, Takeshi Azuma,

Veterinary medicine and infectious diseases

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 ( cag PAI) genes. In the present study, to consider the association of molecular genetics between vacA and the cag PAI 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) (χ2 = 12.64, P = 0.00057). These data suggest that the molecular genetics of vacA and cag PAI are associated and that the Western group with vacA and cag PAI genes is associated with peptic ulcer disease.