title: Non-pylori Helicobacteraceae in the upper digestive tract of asymptomatic Venezuelan subjects: detection of Helicobacter cetorum-like and Candidatus Wolinella africanus-like DNA.
abstract: BACKGROUND
  The spectrum of human non-pylori Helicobacter infections is expanding, with species such as H. heilmannii and H. felis occasionally being associated with gastritis. However, the existence of non-pylori Helicobacter colonization in asymptomatic subjects has not been evaluated. The aim of this study was to investigate whether Helicobacter species other than pylori are present in the upper digestive tract of asymptomatic human subjects.
  
  
  METHODS
  A Helicobacteraceae-specific semi-nested polymerase chain reaction (PCR) assay was used to detect Helicobacter-like organisms in the upper digestive tract of 91 Venezuelan volunteers (aged 18-68 years, 41 females, 50 males). Species were identified by denaturing gradient gel electrophoresis analysis and sequencing of the PCR products.
  
  
  RESULTS
  We detected DNA sharing 99-100% sequence identity in over 300-400 bp with the 16S rRNA genes of H. pylori, H. cetorum, and Candidatus Wolinella africanus in 76%, 16%, and 15% of the subjects, respectively. Multiple colonization was documented in 10% of the subjects: H. cetorum and Candidatus W. africanus (4%), H. pylori and Candidatus W. africanus (4%), and H. pylori and H. cetorum (2%).
  
  
  CONCLUSIONS
  Our results suggest that non-pylori Helicobacteraceae colonization is relatively common in the Venezuelan asymptomatic population. This is the first report documenting the presence of H. cetorum DNA in the human upper digestive tract, and the second report of the recently discovered Candidatus W. africanus.
authors.affiliation: Centro de Biofísica y Bioquimíca, Instituto Venezolano de Investigaciones Científicas, Miranda, Venezuela.
authors.forename: M Alexandra
authors.initials: MA
authors.lastname: García-Amado
authors.forename: Waleed Abu
authors.initials: WA
authors.lastname: Al-Soud
authors.forename: Pedro
authors.initials: P
authors.lastname: Borges-Landaéz
authors.forename: Monica
authors.initials: M
authors.lastname: Contreras
authors.forename: Samandhy
authors.initials: S
authors.lastname: Cedeño
authors.forename: Estalina
authors.initials: E
authors.lastname: Baéz-Ramírez
authors.forename: M Gloria
authors.initials: MG
authors.lastname: Domínguez-Bello
authors.forename: Torkel
authors.initials: T
authors.lastname: Wadström
authors.forename: Pulchérie
authors.initials: P
authors.lastname: Gueneau
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D004269:DNA, Bacterial / Q000032:analysis; D005260:Female; D041981:Gastrointestinal Tract / Q000382:microbiology*; D016905:Gram-Negative Bacterial Infections / Q000453:epidemiology* / Q000382:microbiology / Q000503:physiopathology; D016998:Helicobacter / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D016481:Helicobacter Infections / Q000453:epidemiology* / Q000382:microbiology / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D015995:Prevalence; D013045:Species Specificity; D014687:Venezuela / Q000453:epidemiology; D016968:Wolinella / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*
chemical_list: D004269:DNA, Bacterial