title: Cross-sectional study of antimicrobial-resistant bacteria in horses. Part 2: Risk factors for faecal carriage of antimicrobial-resistant Escherichia coli in horses.
abstract: BACKGROUND
  The increasing prevalence of antimicrobial resistant bacteria such as antimicrobial-resistant and extended spectrum β-lactamase (ESBL)-producing Escherichia coli represents a significant problem for human and veterinary medicine. Despite this, the risk factors for faecal carriage of such bacteria by horses in the UK, particularly those in the wider community, have not been well described.
  
  
  OBJECTIVE
  To characterise the risk factors for faecal carriage of antimicrobial-resistant E. coli amongst horses in the mainland UK.
  
  
  METHODS
  A cross-sectional study of horses recruited by 65 randomly selected equine veterinary practices was conducted, with a faecal sample collected and self-administered questionnaire completed by the horse owner. Faecal samples were cultured for antimicrobial-resistant E. coli, with isolates confirmed as E. coli having their antimicrobial resistance profile determined. Multilevel, multivariable logistic regression models were used to investigate risk factors for the carriage of antimicrobial-resistant E. coli in the sample population.
  
  
  RESULTS
  Faecal samples and completed questionnaires were obtained for 627 horses located on 475 premises. Recent hospitalisation, contact with specific types of nonequid animals, the type of premises, the surrounding land use, the reason for veterinary treatment received in the last 6 months and antimicrobial treatment in the previous 10 days were identified as risk factors for many of the antimicrobial-resistance outcomes considered. Being stabled on the same yard as a recently hospitalised horse was identified as a risk factor for increased risk of carriage of ESBL-producing E. coli.
  
  
  CONCLUSIONS
  Increasing antimicrobial resistance may have significant health implications for the horse population of Great Britain. This form of epidemiological investigation highlights potential risk factors that may be controlled to limit the extent of the problem.
authors.affiliation: National Centre for Zoonosis Research, School of Veterinary Sciences, University of Liverpool, UK. thomas.maddox@liverpool.ac.uk
authors.forename: T W
authors.initials: TW
authors.lastname: Maddox
authors.forename: G L
authors.initials: GL
authors.lastname: Pinchbeck
authors.forename: P D
authors.initials: PD
authors.lastname: Clegg
authors.forename: A L
authors.initials: AL
authors.lastname: Wedley
authors.forename: S
authors.initials: S
authors.lastname: Dawson
authors.forename: N J
authors.initials: NJ
authors.lastname: Williams
mesh_terms: D000822:Animal Husbandry; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002353:Carrier State / Q000453:epidemiology / Q000382:microbiology / Q000662:veterinary*; D003430:Cross-Sectional Studies; D003625:Data Collection; D024901:Drug Resistance, Multiple, Bacterial; D004927:Escherichia coli Infections / Q000453:epidemiology / Q000382:microbiology / Q000662:veterinary*; D005243:Feces / Q000382:microbiology*; D005260:Female; D006734:Horse Diseases / Q000453:epidemiology / Q000382:microbiology*; D006736:Horses; D006799:Housing, Animal; D008297:Male; D012307:Risk Factors; D011795:Surveys and Questionnaires; D006113:United Kingdom / Q000453:epidemiology
chemical_list: D000900:Anti-Bacterial Agents