title: Extensive characterization of Campylobacter jejuni chicken isolates to uncover genes involved in the ability to compete for gut colonization.
abstract: BACKGROUND
  Campylobacter jejuni is responsible for human foodborne enteritis. This bacterium is a remarkable colonizer of the chicken gut, with some strains outcompeting others for colonization. To better understand this phenomenon, the objective of this study was to extensively characterize the phenotypic performance of C. jejuni chicken strains and associate their gut colonizing ability with specific genes.
  
  
  RESULTS
  C. jejuni isolates (n = 45) previously analyzed for the presence of chicken colonization associated genes were further characterized for phenotypic properties influencing colonization: autoagglutination and chemotaxis as well as adhesion to and invasion of primary chicken caecal cells. This allowed strains to be ranked according to their in vitro performance. After their in vitro capacity to outcompete was demonstrated in vivo, strains were then typed by comparative genomic fingerprinting (CGF). In vitro phenotypical properties displayed a linear variability among the tested strains. Strains possessing higher scores for phenotypical properties were able to outcompete others during chicken colonization trials. When the gene content of strains was compared, some were associated with different phenotypical scores and thus with different outcompeting capacities. Use of CGF profiles showed an extensive genetic variability among the studied strains and suggested that the outcompeting capacity is not predictable by CGF profile.
  
  
  CONCLUSIONS
  This study revealed a wide array of phenotypes present in C. jejuni strains, even though they were all recovered from chicken caecum. Each strain was classified according to its in vitro competitive potential and its capacity to compete for chicken gut colonization was associated with specific genes. This study also exposed the disparity existing between genetic typing and phenotypical behavior of C. jejuni strains.
authors.affiliation: Department of Pathology and Microbiology, NSERC Industrial Research Chair in Meat-Safety (CRSV), University of Montreal, Veterinary Medicine Faculty, Saint-Hyacinthe, QC, Canada. alexandre.thibodeau@live.ca.|Department of Pathology and Microbiology, Swine and Avian Infectious Disease Research Centre (CRIPA), University of Montreal, Veterinary Medicine Faculty, Saint-Hyacinthe, QC, Canada. alexandre.thibodeau@live.ca.|Department of Pathology and Microbiology, Groupe de recherche et d'enseignement en salubrité alimentaire (GRESA), University of Montreal, Veterinary Medicine Faculty, Saint-Hyacinthe, QC, Canada. alexandre.thibodeau@live.ca.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Thibodeau
authors.affiliation: Department of Pathology and Microbiology, NSERC Industrial Research Chair in Meat-Safety (CRSV), University of Montreal, Veterinary Medicine Faculty, Saint-Hyacinthe, QC, Canada. philippe.fravalo@umontreal.ca.|Department of Pathology and Microbiology, Swine and Avian Infectious Disease Research Centre (CRIPA), University of Montreal, Veterinary Medicine Faculty, Saint-Hyacinthe, QC, Canada. philippe.fravalo@umontreal.ca.|Department of Pathology and Microbiology, Groupe de recherche et d'enseignement en salubrité alimentaire (GRESA), University of Montreal, Veterinary Medicine Faculty, Saint-Hyacinthe, QC, Canada. philippe.fravalo@umontreal.ca.
authors.forename: Philippe
authors.initials: P
authors.lastname: Fravalo
authors.affiliation: Public Health Agency of Canada, Laboratory for Foodborne Zoonoses, Lethbridge, AB, Canada. eduardo.taboada@phac-aspc.gc.ca.
authors.forename: Eduardo N
authors.initials: EN
authors.lastname: Taboada
authors.affiliation: Department of Pathology and Microbiology, NSERC Industrial Research Chair in Meat-Safety (CRSV), University of Montreal, Veterinary Medicine Faculty, Saint-Hyacinthe, QC, Canada. sylvette.laurent-lewandowski@umontreal.ca.|Department of Pathology and Microbiology, Swine and Avian Infectious Disease Research Centre (CRIPA), University of Montreal, Veterinary Medicine Faculty, Saint-Hyacinthe, QC, Canada. sylvette.laurent-lewandowski@umontreal.ca.
authors.forename: Sylvette
authors.initials: S
authors.lastname: Laurent-Lewandowski
authors.affiliation: Department of Pathology and Microbiology, Groupe de recherche et d'enseignement en salubrité alimentaire (GRESA), University of Montreal, Veterinary Medicine Faculty, Saint-Hyacinthe, QC, Canada. evelyne.guevremont@agr.gc.ca.|Agriculture and Agri-Food Canada, Food Research and Development Centre, St-Hyacinthe, QC, Canada. evelyne.guevremont@agr.gc.ca.
authors.forename: Evelyne
authors.initials: E
authors.lastname: Guévremont
authors.affiliation: Department of Pathology and Microbiology, NSERC Industrial Research Chair in Meat-Safety (CRSV), University of Montreal, Veterinary Medicine Faculty, Saint-Hyacinthe, QC, Canada. sylvain.quessy@umontreal.ca.|Department of Pathology and Microbiology, Swine and Avian Infectious Disease Research Centre (CRIPA), University of Montreal, Veterinary Medicine Faculty, Saint-Hyacinthe, QC, Canada. sylvain.quessy@umontreal.ca.|Department of Pathology and Microbiology, Groupe de recherche et d'enseignement en salubrité alimentaire (GRESA), University of Montreal, Veterinary Medicine Faculty, Saint-Hyacinthe, QC, Canada. sylvain.quessy@umontreal.ca.
authors.forename: Sylvain
authors.initials: S
authors.lastname: Quessy
authors.affiliation: Department of Pathology and Microbiology, NSERC Industrial Research Chair in Meat-Safety (CRSV), University of Montreal, Veterinary Medicine Faculty, Saint-Hyacinthe, QC, Canada. ann.letellier@umontreal.ca.|Department of Pathology and Microbiology, Swine and Avian Infectious Disease Research Centre (CRIPA), University of Montreal, Veterinary Medicine Faculty, Saint-Hyacinthe, QC, Canada. ann.letellier@umontreal.ca.|Department of Pathology and Microbiology, Groupe de recherche et d'enseignement en salubrité alimentaire (GRESA), University of Montreal, Veterinary Medicine Faculty, Saint-Hyacinthe, QC, Canada. ann.letellier@umontreal.ca.
authors.forename: Ann
authors.initials: A
authors.lastname: Letellier
mesh_terms: D000818:Animals; D001422:Bacterial Adhesion; D002169:Campylobacter Infections / Q000382:microbiology / Q000662:veterinary*; D016123:Campylobacter jejuni / Q000235:genetics* / Q000254:growth & development / Q000302:isolation & purification / Q000502:physiology*; D002633:Chemotaxis; D002645:Chickens / Q000382:microbiology*; D004705:Endocytosis; D004847:Epithelial Cells / Q000382:microbiology; D041981:Gastrointestinal Tract / Q000382:microbiology*; D005798:Genes, Bacterial; D056726:Genetic Association Studies; D014774:Virulence