title: Evaluation of the clinical significance of homB, a novel candidate marker of Helicobacter pylori strains associated with peptic ulcer disease.
abstract: BACKGROUND
  homB codes for a putative Helicobacter pylori outer membrane protein and has previously been associated with peptic ulcer disease (PUD) in children.
  
  
  METHODS
  A total of 190 H. pylori strains isolated from children and adults were studied to evaluate the clinical importance of the homB gene. In vitro experiments were performed to identify HomB mechanisms of bacterial pathogenicity.
  
  
  RESULTS
  Characterization of the isolates demonstrated that homB was significantly associated with PUD in 86 children (odds ratio [OR], 7.64 [95% confidence interval {CI}, 2.65-22.05]) and in 32 adults < or =40 years of age (OR, 11.25 [95% CI, 1.86-68.13]). homB was correlated with the presence of cagA, babA2, vacAs1, hopQI, and oipA "on" genotype (P< .001) The HomB protein was found to be expressed in the H. pylori outer membrane and was noted to be antigenic in humans. H. pylori homB knockout mutant strains presented reduced ability to induce interleukin-8 secretion from human gastric epithelial cells, as well as reduced capacity to bind to these cells. Both of these functions correlated with the number of homB copies present in a strain.
  
  
  CONCLUSIONS
  homB can be considered a comarker of H. pylori strains associated with PUD. Moreover, results strongly suggest that HomB is involved in the inflammatory response and in H. pylori adherence, constituting a novel putative virulence factor.
authors.affiliation: Departamento de Doenças Infecciosas, Instituto Nacional Saúde Dr Ricardo Jorge, Lisbon, Portugal. francis.megraud@chu-bordeaux.fr
authors.forename: Mónica
authors.initials: M
authors.lastname: Oleastro
authors.forename: Rita
authors.initials: R
authors.lastname: Cordeiro
authors.forename: Jonathan
authors.initials: J
authors.lastname: Ferrand
authors.forename: Baltazar
authors.initials: B
authors.lastname: Nunes
authors.forename: Philippe
authors.initials: P
authors.lastname: Lehours
authors.forename: Isabel
authors.initials: I
authors.lastname: Carvalho-Oliveira
authors.forename: Ana I
authors.initials: AI
authors.lastname: Mendes
authors.forename: Deborah
authors.initials: D
authors.lastname: Penque
authors.forename: Lurdes
authors.initials: L
authors.lastname: Monteiro
authors.forename: Francis
authors.initials: F
authors.lastname: Mégraud
authors.forename: Armelle
authors.initials: A
authors.lastname: Ménard
mesh_terms: D000328:Adult; D000942:Antigens, Bacterial; D001422:Bacterial Adhesion; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics* / Q000378:metabolism; D045744:Cell Line, Tumor; D002648:Child; D004847:Epithelial Cells / Q000378:metabolism; D005260:Female; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D005819:Genetic Markers; D014644:Genetic Variation; D016480:Helicobacter pylori / Q000235:genetics* / Q000472:pathogenicity; D006801:Humans; D016209:Interleukin-8 / Q000378:metabolism; D016015:Logistic Models; D008297:Male; D016017:Odds Ratio; D010437:Peptic Ulcer / Q000382:microbiology*; D014774:Virulence
chemical_list: D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D005819:Genetic Markers; D016209:Interleukin-8