title: Chicken Caecal Microbiome Modifications Induced by Campylobacter jejuni Colonization and by a Non-Antibiotic Feed Additive.
abstract: Campylobacter jejuni is an important zoonotic foodborne pathogen causing acute gastroenteritis in humans. Chickens are often colonized at very high numbers by C. jejuni, up to 10(9) CFU per gram of caecal content, with no detrimental effects on their health. Farm control strategies are being developed to lower the C. jejuni contamination of chicken food products in an effort to reduce human campylobacteriosis incidence. It is believed that intestinal microbiome composition may affect gut colonization by such undesirable bacteria but, although the chicken microbiome is being increasingly characterized, information is lacking on the factors affecting its modulation, especially by foodborne pathogens. This study monitored the effects of C. jejuni chicken caecal colonization on the chicken microbiome in healthy chickens. It also evaluated the capacity of a feed additive to affect caecal bacterial populations and to lower C. jejuni colonization. From day-0, chickens received or not a microencapsulated feed additive and were inoculated or not with C. jejuni at 14 days of age. Fresh caecal content was harvested at 35 days of age. The caecal microbiome was characterized by real time quantitative PCR and Ion Torrent sequencing. We observed that the feed additive lowered C. jejuni caecal count by 0.7 log (p<0.05). Alpha-diversity of the caecal microbiome was not affected by C. jejuni colonization or by the feed additive. C. jejuni colonization modified the caecal beta-diversity while the feed additive did not. We observed that C. jejuni colonization was associated with an increase of Bifidobacterium and affected Clostridia and Mollicutes relative abundances. The feed additive was associated with a lower Streptococcus relative abundance. The caecal microbiome remained relatively unchanged despite high C. jejuni colonization. The feed additive was efficient in lowering C. jejuni colonization while not disturbing the caecal microbiome.
authors.affiliation: NSERC Industrial Research Chair in Meat-Safety (CRSV), Université de Montréal, Faculty of Veterinary Medicine, Saint-Hyacinthe, Québec, Canada; Swine and Avian Infectious Disease Research Centre (CRIPA), Université de Montréal, Faculty of Veterinary Medicine, Saint-Hyacinthe, Québec, Canada; Groupe de recherche et d'enseignement en salubrité alimentaire (GRESA), Université de Montréal, Faculty of Veterinary Medicine, Saint-Hyacinthe, Québec, Canada.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Thibodeau
authors.affiliation: NSERC Industrial Research Chair in Meat-Safety (CRSV), Université de Montréal, Faculty of Veterinary Medicine, Saint-Hyacinthe, Québec, Canada; Swine and Avian Infectious Disease Research Centre (CRIPA), Université de Montréal, Faculty of Veterinary Medicine, Saint-Hyacinthe, Québec, Canada; Groupe de recherche et d'enseignement en salubrité alimentaire (GRESA), Université de Montréal, Faculty of Veterinary Medicine, Saint-Hyacinthe, Québec, Canada.
authors.forename: Philippe
authors.initials: P
authors.lastname: Fravalo
authors.affiliation: National Research Council of Canada, Montréal, Québec, Canada.
authors.forename: Étienne
authors.initials: É
authors.lastname: Yergeau
authors.affiliation: Swine and Avian Infectious Disease Research Centre (CRIPA), Université de Montréal, Faculty of Veterinary Medicine, Saint-Hyacinthe, Québec, Canada; Groupe de recherche et d'enseignement en salubrité alimentaire (GRESA), Université de Montréal, Faculty of Veterinary Medicine, Saint-Hyacinthe, Québec, Canada.
authors.forename: Julie
authors.initials: J
authors.lastname: Arsenault
authors.affiliation: Jefo Nutrition Inc, Saint-Hyacinthe, Québec, Canada.
authors.forename: Ludovic
authors.initials: L
authors.lastname: Lahaye
authors.affiliation: NSERC Industrial Research Chair in Meat-Safety (CRSV), Université de Montréal, Faculty of Veterinary Medicine, Saint-Hyacinthe, Québec, Canada; Swine and Avian Infectious Disease Research Centre (CRIPA), Université de Montréal, Faculty of Veterinary Medicine, Saint-Hyacinthe, Québec, Canada; Groupe de recherche et d'enseignement en salubrité alimentaire (GRESA), Université de Montréal, Faculty of Veterinary Medicine, Saint-Hyacinthe, Québec, Canada.
authors.forename: Ann
authors.initials: A
authors.lastname: Letellier
mesh_terms: D000821:Animal Feed; D000818:Animals; D001644:Bifidobacterium / Q000235:genetics; D044822:Biodiversity; D016123:Campylobacter jejuni / Q000502:physiology*; D002432:Cecum / Q000382:microbiology*; D002645:Chickens / Q000382:microbiology*; D005503:Food Additives / Q000494:pharmacology*; D064307:Microbiota / Q000187:drug effects* / Q000235:genetics; D058889:Molecular Typing; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D013011:Sorbic Acid / Q000494:pharmacology; D013943:Thymol / Q000494:pharmacology
chemical_list: D005503:Food Additives; D012336:RNA, Ribosomal, 16S; D013943:Thymol; D013011:Sorbic Acid