Alexandre Thibodeau
University of Montreal, Canada
Title: Campylobacter jejuni and chicken colonisation: different strains, different abilities
Biography
Biography: Alexandre Thibodeau
Abstract
Campylobacter jejuni is a foodborne pathogen mainly associated to chickens, reaching caecal concentration up to 109 CFU/g. Scarce reports mention clinical signs associated to C.jejuni chicken colonization, making it a bacteria acting like a commensal. One aspect of our work focuses on the characterization of the ability of C.jejuni to colonize the chicken caecum. C. jejuni chicken strains were characterized for their ability to autoagglutinate, to be attracted to mucins and to adhere or invade chicken primary caecal cells; these phenotypes having individually been linked to the ability of strains to colonize chickens. In parallel, a microarray was developed to screens the strains for genes that could be linked to colonization. Strains were also typed by comparative genomic fingerprinting. We confirmed in vivo that strains possessing different phenotypes also possessed different abilities to compete for the colonization of the chicken gut. This ability could be associated with genes such as genes coding for arsenical resistance. Representative strains possessing the best competition abilities were also used in a serie of in vivo chickens studies to assess the efficiency of control methods to lower C. jejuni chicken caecal loads. Limited results were obtained, showing the complexity of the intestinal microbial ecosystem. The effect of the colonisation of these strains on the chicken microbiota was also assessed and we observed small disturbance of some bacterial populations. Our strain collection is currently being sequenced and further characterized in vitro to deepen our understanding of C.jejuni chicken colonization.