title: Changes in bacterial community composition of Escherichia coli O157:H7 super-shedder cattle occur in the lower intestine.
abstract: Escherichia coli O157:H7 is a foodborne pathogen that colonizes ruminants. Cattle are considered the primary reservoir of E. coli O157:H7 with super-shedders, defined as individuals excreting > 104 E. coli O157:H7 CFU g-1 feces. The mechanisms leading to the super-shedding condition are largely unknown. Here, we used 16S rRNA gene pyrosequencing to examine the composition of the fecal bacterial community in order to investigate changes in the bacterial microbiota at several locations along the digestive tract (from the duodenum to the rectal-anal junction) in 5 steers previously identified as super-shedders and 5 non-shedders. The overall bacterial community structure did not differ by E. coli O157:H7 shedding status; but several differences in the relative abundance of taxa and OTUs were noted between the two groups. The genus Prevotella was most enriched in the non-shedders while the genus Ruminococcus and the Bacteroidetes phylum were notably enriched in the super-shedders. There was greater bacterial diversity and richness in samples collected from the lower- as compared to the upper gastrointestinal tract (GI). The spiral colon was the only GI location that differed in terms of bacterial diversity between super-shedders and non-shedders. These findings reinforced linkages between E. coli O157:H7 colonization in cattle and the nature of the microbial community inhabiting the digestive tract of super-shedders.
authors.affiliation: Agriculture and Agri-Food Canada, Lethbridge Research and Development Centre, Lethbridge, Alberta, Canada.
authors.forename: Rahat
authors.initials: R
authors.lastname: Zaheer
authors.affiliation: UMR Génie et Microbiologie des Procédés Alimentaires, AgroParisTech, INRA, Université Paris-Saclay, Thiverval-Grignon, France.
authors.forename: Eric
authors.initials: E
authors.lastname: Dugat-Bony
authors.affiliation: Agriculture and Agri-Food Canada, Lethbridge Research and Development Centre, Lethbridge, Alberta, Canada.
authors.forename: Devon
authors.initials: DB
authors.lastname: Holman
authors.affiliation: Department of Biological Sciences, University of Lethbridge, Lethbridge, Alberta, Canada.
authors.forename: Elodie
authors.initials: E
authors.lastname: Cousteix
authors.affiliation: Department of Biological Sciences, University of Lethbridge, Lethbridge, Alberta, Canada.
authors.forename: Yong
authors.initials: Y
authors.lastname: Xu
authors.affiliation: Agriculture and Agri-Food Canada, Lethbridge Research and Development Centre, Lethbridge, Alberta, Canada.
authors.forename: Krysty
authors.initials: K
authors.lastname: Munns
authors.affiliation: Agriculture and Agri-Food Canada, Lethbridge Research and Development Centre, Lethbridge, Alberta, Canada.
authors.forename: Lorna J
authors.initials: LJ
authors.lastname: Selinger
authors.affiliation: Agriculture and Agri-Food Canada, Lethbridge Research and Development Centre, Lethbridge, Alberta, Canada.
authors.forename: Rutn
authors.initials: R
authors.lastname: Barbieri
authors.affiliation: Agriculture and Agri-Food Canada, Lethbridge Research and Development Centre, Lethbridge, Alberta, Canada.
authors.forename: Trevor
authors.initials: T
authors.lastname: Alexander
authors.affiliation: Agriculture and Agri-Food Canada, Lethbridge Research and Development Centre, Lethbridge, Alberta, Canada.
authors.forename: Tim A
authors.initials: TA
authors.lastname: McAllister
authors.affiliation: Department of Biological Sciences, University of Lethbridge, Lethbridge, Alberta, Canada.
authors.forename: L Brent
authors.initials: LB
authors.lastname: Selinger
mesh_terms: D000818:Animals; D057138:Bacterial Shedding / Q000502:physiology*; D044822:Biodiversity; D002417:Cattle; D016002:Discriminant Analysis; D019453:Escherichia coli O157 / Q000502:physiology*; D000069196:Gastrointestinal Microbiome; D007422:Intestines / Q000382:microbiology*; D025341:Principal Component Analysis