title: Variable and strain dependent colonisation of chickens by Escherichia coli O157.
abstract: The prevalence of enterohaemorrhagic Escherichia coli (EHEC) O157 in poultry is considered minimal compared with other species, especially ruminants. However, deliberate inoculation studies have shown that poultry are readily and persistently infected by this organism but that the mechanism of colonisation is independent of intimin, a recognised factor in host-EHEC interactions in mammalian species, and may be dependent upon flagella. Few strains of EHEC O157 have been tested in poultry and here 1-day-old and 6-week-old chicks were inoculated with seven non-toxigenic E. coli O157 strains in separate experiments. Persistence was measured semi-quantitatively by bacteriological assessment of E. coli O157 cultured from cloacal swabs (shedding score). In the 1-day-old chick model that was monitored for 43 days, all seven strains established well after inoculation. In the 6-week-old chicken model, one strain established and gave consistently high shedding for the duration of the experiment (156 days). Whereas of the remaining six strains, two persisted for 113 days, two persisted for 43 days, one persisted for 22 days and one strain was never detected.
authors.affiliation: Department for Food and Environmental Safety, Veterinary Laboratories Agency, Woodham Lane, New Haw, Addlestone, Surrey KT15 3NB, UK.
authors.forename: R M
authors.initials: RM
authors.lastname: La Ragione
authors.forename: A
authors.initials: A
authors.lastname: Best
authors.forename: K
authors.initials: K
authors.lastname: Sprigings
authors.forename: E
authors.initials: E
authors.lastname: Liebana
authors.forename: G R
authors.initials: GR
authors.lastname: Woodward
authors.forename: A R
authors.initials: AR
authors.lastname: Sayers
authors.forename: M J
authors.initials: MJ
authors.lastname: Woodward
mesh_terms: D000367:Age Factors; D000818:Animals; D001422:Bacterial Adhesion / Q000502:physiology*; D001426:Bacterial Proteins / Q000235:genetics; D002645:Chickens; D002988:Cloaca / Q000382:microbiology; D015169:Colony Count, Microbial; D016521:Electrophoresis, Gel, Pulsed-Field / Q000662:veterinary; D004927:Escherichia coli Infections / Q000382:microbiology / Q000662:veterinary*; D019453:Escherichia coli O157 / Q000235:genetics / Q000302:isolation & purification / Q000472:pathogenicity* / Q000502:physiology; D005260:Female; D005407:Flagella / Q000502:physiology; D009154:Mutation; D016133:Polymerase Chain Reaction / Q000662:veterinary; D011201:Poultry Diseases / Q000382:microbiology*; D011897:Random Allocation; D012808:Sigma Factor / Q000235:genetics; D013047:Specific Pathogen-Free Organisms
chemical_list: D001426:Bacterial Proteins; D012808:Sigma Factor; C069567:sigma factor KatF protein, Bacteria