title: Histological variety of gastric carcinoma and Helicobacter pylori cagA and vacA polymorphism.
abstract: BACKGROUND
  Helicobacter pylori infection may increase the risk of both histotypes of gastric carcinoma (GC): intestinal (IGC) and diffuse (DGC). Polymorphism of the main H. pylori virulence factors, cagA and vacA, could have a different impact on the histological variety of GC.
  
  
  METHODS
  Two hundred and twenty-six H. pylori colonies were examined from 28 GC patients: 15 with IGC and 13 with DGC. DNA was extracted from bacteria and a PCR was performed using primers specific for cagA, the 3' cagA variable region and s and m regions of vacA.
  
  
  RESULTS
  There were 214 cagA+ strains and 55.61% of them were isolated from IGC cases; there were 12 cagA- colonies and they were all isolated from DGC (P<0.001). Most patients were infected by strains with more than one cagA structural type. No strains with a particular cagA type were found to be significantly more frequent in either histological variety of GC. A percentage of 43.90 of strains with vacA subtype s1/m1 were isolated from IGC, whereas 80.95% of vacA subtype s1/m2 strains were isolated from DGC cases (P<0.001).
  
  
  CONCLUSIONS
  Polymorphism of the main virulence genes of H. pylori may play different roles in the pathogenesis of IGC and DGC.
authors.affiliation: Departments of aMedical and Surgical Sciences and Neurosciences bMedical Biotechnology cMolecular and Developmental Medicine dHuman Pathology and Oncology, Section of Pathology, University of Siena, Siena eExperimental Zooprofilactic Institute of Lazio and Tuscany, Epidemiological Observatory, Rome, Italy.
authors.forename: Natale
authors.initials: N
authors.lastname: Figura
authors.forename: Marcello
authors.initials: M
authors.lastname: Valassina
authors.forename: Elena
authors.initials: E
authors.lastname: Moretti
authors.forename: Carla
authors.initials: C
authors.lastname: Vindigni
authors.forename: Giulia
authors.initials: G
authors.lastname: Collodel
authors.forename: Francesca
authors.initials: F
authors.lastname: Iacoponi
authors.forename: Nicola
authors.initials: N
authors.lastname: Giordano
authors.forename: Francesco
authors.initials: F
authors.lastname: Roviello
authors.forename: Daniele
authors.initials: D
authors.lastname: Marrelli
mesh_terms: D000942:Antigens, Bacterial / Q000235:genetics*; D001426:Bacterial Proteins / Q000235:genetics*; D002277:Carcinoma / Q000382:microbiology* / Q000473:pathology*; D004269:DNA, Bacterial / Q000235:genetics*; D016481:Helicobacter Infections / Q000150:complications / Q000175:diagnosis / Q000382:microbiology*; D016480:Helicobacter pylori / Q000235:genetics* / Q000302:isolation & purification / Q000472:pathogenicity; D006801:Humans; D010641:Phenotype; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D012307:Risk Factors; D013274:Stomach Neoplasms / Q000382:microbiology* / Q000473:pathology*; D014774:Virulence / Q000235:genetics
chemical_list: D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D004269:DNA, Bacterial; C074689:VacA protein, Helicobacter pylori; C080866:cagA protein, Helicobacter pylori