title: Diversity of Helicobacter pylori cagA and vacA genes in Costa Rica: its relationship with atrophic gastritis and gastric cancer.
abstract: BACKGROUND
  Associations between Helicobacter pylori gene diversity and gastric cancer have not been reported on in Costa Rica, despite its being one of the countries with the highest gastric cancer incidence and mortality rates in the world. The aim of this study was to determine the prevalence of H. pylori cagA and vacA genes and investigate whether it could be correlated with atrophic gastritis (AG) and gastric cancer (GC) in Costa Rica.
  
  
  METHODS
  Genomic DNAs from isolates of 104 patients classified into two groups: non-atrophic gastritis group (n = 68) and atrophic gastritis group (n = 36), were subjected to PCR-based genotyping of cagA and vacA genes and their correlation with clinical outcome was investigated. Total DNA extractions from gastric tissues of 25 H. pylori-infected gastric cancer patients were utilized for comparative purposes.
  
  
  RESULTS
  The presence of cagA (75.3%), vacA s1b (75.3%), and vacA m1 (74.2%) was detected, and colonization by strains with different vacA genotypes in the same stomach was found in 9.7% of the patients. Age- and sex-adjusted vacA s1b and vacA m1 were associated with GC while only vacA m1 was significantly associated with AG. A tendency for association between cagA and vacA s1b, and AG was reported.
  
  
  CONCLUSIONS
  The prevalence status of the cagA and vacA (s1/m1) genes in Costa Rica seems to fall between that found in European/North American and East Asian countries, and both cagA and vacA seem to have clinical relevance in this country.
authors.affiliation: Department of Clinical Laboratory Medicine, Kochi Medical School, Kochi University, Nankoku City, Kochi 783-8505, Japan.
authors.forename: Sergio A
authors.initials: SA
authors.lastname: Con
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Takeuchi
authors.forename: Ana L
authors.initials: AL
authors.lastname: Valerín
authors.forename: Reinaldo
authors.initials: R
authors.lastname: Con-Wong
authors.forename: Gil R
authors.initials: GR
authors.lastname: Con-Chin
authors.forename: Vicky G
authors.initials: VG
authors.lastname: Con-Chin
authors.forename: Mitsuaki
authors.initials: M
authors.lastname: Nishioka
authors.forename: Fernando
authors.initials: F
authors.lastname: Mena
authors.forename: Fernando
authors.initials: F
authors.lastname: Brenes
authors.forename: Nobufumi
authors.initials: N
authors.lastname: Yasuda
authors.forename: Keijiro
authors.initials: K
authors.lastname: Araki
authors.forename: Tetsuro
authors.initials: T
authors.lastname: Sugiura
mesh_terms: D000942:Antigens, Bacterial / Q000235:genetics*; D001426:Bacterial Proteins / Q000235:genetics*; D003364:Costa Rica / Q000453:epidemiology; D005260:Female; D005757:Gastritis, Atrophic / Q000453:epidemiology / Q000382:microbiology / Q000503:physiopathology*; D014644:Genetic Variation; D016481:Helicobacter Infections / Q000150:complications* / Q000382:microbiology; D016480:Helicobacter pylori / Q000235:genetics / Q000472:pathogenicity*; D006801:Humans; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D015995:Prevalence; D013274:Stomach Neoplasms / Q000453:epidemiology / Q000382:microbiology / Q000503:physiopathology*
chemical_list: D000942:Antigens, Bacterial; D001426:Bacterial Proteins; C074689:VacA protein, Helicobacter pylori; C080866:cagA protein, Helicobacter pylori