title: Prevalence of Helicobacter pylori cagA and vacA genes in Cypriot patients.
abstract: BACKGROUND
  The prevalence of H. pylori varies with geographic locations. To date there are no epidemiological data on its prevalence in Cyprus; therefore, we determined the prevalence and molecular characteristics of H. pylori infection in Cypriot patients.
  
  
  METHODS
  DNA extracted from 103 gastric biopsies was analyzed for the presence of H. pylori by PCR using primers for ureA. H. pylori-positive biopsies were characterized by PCR using specific primers for cagA and vacA genes. The presence of clarithromycin-associated resistant mutations such as A2143G, A2142G, A2142C in 23S rRNA gene of H. pylori-positive patients was determined using a real-time PCR allelic discrimination assay.
  
  
  RESULTS
  H. pylori was detected in 41 (39.8%) biopsies and, out of these, 17 (41.5%) tested positive for the cagA gene. The vacA alleles m1, m2, s1a, s1b, and s2 were detected in 7 (17.1%), 34 (82.9%), 12 (29.3%), 2 (4.9%), and 22 (53.7%) isolates, respectively. One (2.4%) biopsy was vacA s1a and s2-positive while one (2.4%) was positive for vacA s1a, s1b, and s2. Three (7.3%) biopsies were untypable for vacA s1, s1b, and s2. The majority (35; 85.4%) of strains were susceptible to clarithromycin while two (4.9%) had the A2143G mutation. Three (7.3%) had a mixture of an A2143G point mutant and susceptible strains while one (2.4%) had a mixture of an A2142G point mutant and susceptible strains.
  
  
  CONCLUSIONS
  The distribution of the virulence factors cagA and vacA in the Cypriot strains resembled that of strains circulating in Middle Eastern countries geographically close to Cyprus.
authors.affiliation: Cyprus Institute of Neurology and Genetics, 6 International Airport Avenue, 2370 Nicosia, Cyprus. krashias.g@unic.ac.cy.
authors.forename: George
authors.initials: G
authors.lastname: Krashias
authors.forename: Stavros
authors.initials: S
authors.lastname: Bashiardes
authors.forename: Alexia
authors.initials: A
authors.lastname: Potamitou
authors.forename: George S
authors.initials: GS
authors.lastname: Potamitis
authors.forename: Christina
authors.initials: C
authors.lastname: Christodoulou
mesh_terms: D000328:Adult; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D000942:Antigens, Bacterial / Q000235:genetics*; D001426:Bacterial Proteins / Q000235:genetics*; D001706:Biopsy; D017291:Clarithromycin / Q000494:pharmacology; D003535:Cyprus / Q000453:epidemiology; D004269:DNA, Bacterial / Q000235:genetics / Q000302:isolation & purification; D024881:Drug Resistance, Bacterial; D005753:Gastric Mucosa / Q000382:microbiology; D016481:Helicobacter Infections / Q000453:epidemiology* / Q000382:microbiology*; D016480:Helicobacter pylori / Q000235:genetics* / Q000302:isolation & purification; D006801:Humans; D058974:Phylogeography; D017354:Point Mutation; D015995:Prevalence; D012338:RNA, Ribosomal, 23S / Q000235:genetics; D014510:Urease / Q000235:genetics; D037521:Virulence Factors / Q000235:genetics*
chemical_list: D000900:Anti-Bacterial Agents; D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D004269:DNA, Bacterial; D012338:RNA, Ribosomal, 23S; C074689:VacA protein, Helicobacter pylori; D037521:Virulence Factors; C080866:cagA protein, Helicobacter pylori; D014510:Urease; D017291:Clarithromycin