title: Distribution of Helicobacter pylori virulence markers in patients with gastroduodenal diseases in a region at high risk of gastric cancer.
abstract: Helicobacter pylori (H. pylori) is a major human pathogen that is responsible for various gastroduodenal diseases. We investigated the prevalence of H. pylori virulence markers in a region at high risk of gastric cancer.
  
  
  METHODS
  One hundred and sixteen H. pylori strains were isolated from patients with gastroduodenal diseases. cagA, the cagA 3' variable region, cagPAI genes, vacA, and dupA genotypes were determined by PCR, and some amplicons of the cagA 3' variable region, cagPAI genes and dupA were sequenced.
  
  
  RESULTS
  cagA was detected in all strains. The cagA 3' variable region of 85 strains (73.3%) was amplified, and the sequences of 24 strains were obtained including 22 strains possessing the East Asian-type. The partial cagPAI presented at a higher frequency in chronic gastritis (44.4%) than that of the severe clinical outcomes (9.7%, p < 0.001). The most prevalent vacA genotypes were s1a/m2 (48.3%) and s1c/m2 (13.8%). Thirty-six strains (31.0%) possessed dupA and sequencing of dupA revealed an ORF of 2449-bp. The prevalence of dupA was significantly higher in strains from patients with the severe clinical outcomes (40.3%) than that from chronic gastritis (20.4%, p = 0.02).
  
  
  CONCLUSIONS
  The high rate of East Asian-type cagA, intact cagPAI, virulent vacA genotypes, and the intact long-type dupA may underlie the high risk of gastric cancer in the region.
authors.affiliation: School of Medical Science and Laboratory Medicine, Jiangsu University, Zhenjiang, Jiangsu 212013, PR China.
authors.forename: Ming-yi
authors.initials: MY
authors.lastname: Wang
authors.forename: Cheng
authors.initials: C
authors.lastname: Chen
authors.forename: Xiao-zhong
authors.initials: XZ
authors.lastname: Gao
authors.forename: Jie
authors.initials: J
authors.lastname: Li
authors.forename: Jing
authors.initials: J
authors.lastname: Yue
authors.forename: Feng
authors.initials: F
authors.lastname: Ling
authors.forename: Xiao-chun
authors.initials: XC
authors.lastname: Wang
authors.forename: Shi-he
authors.initials: SH
authors.lastname: Shao
mesh_terms: D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D005838:Genotype; D016481:Helicobacter Infections / Q000382:microbiology*; D016480:Helicobacter pylori / Q000235:genetics* / Q000302:isolation & purification; D006801:Humans; D010437:Peptic Ulcer / Q000382:microbiology*; D016133:Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D013274:Stomach Neoplasms / Q000453:epidemiology / Q000382:microbiology; D037521:Virulence Factors / Q000235:genetics*
chemical_list: D004269:DNA, Bacterial; D037521:Virulence Factors