Cross‐sectional study of antimicrobial‐resistant bacteria in horses. Part 2: Risk factors for faecal carriage of antimicrobial‐resistant Escherichia coli in horses

Abstract

SummaryReasons for performing study: The increasing prevalence of antimicrobial resistant bacteria such as antimicrobial-resistant and extended spectrum b-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. Objectives: 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 and potential relevance: 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.

Risk factors for faecal colonisation with Escherichia coli producing extended‐spectrum and plasmid‐mediated AmpC β‐lactamases in dogs

“…Preliminary simulations using the procedures outlined by Machin and Campbell (2005) were carried out, assuming an a-level of 5 per cent, a CI of width 10 per cent, and considering an expected prevalence of ESBL- and pAmpC-producing E. coli of 10 per cent. This prevalence was estimated based on the prevalence of ESBL-producing E. coli found by others authors (Maddox and others 2012). Under these circumstances, the estimated number of dogs to be sampled was 139.…”

‘Disperse abroad in the land’: the role of wildlife in the dissemination of antimicrobial resistance

“…By contrast, 'acquired' AMR is the result of exposure to antimicrobial drugs which promotes resistance by selecting bacteria within a population with genetic traits conferring resistance. Thus, the selection of AMR in both pathogens and the normal gut microbiota of livestock and humans is believed to be largely a consequence of increased selective pressure provided by clinical antimicrobial use: recent hospitalization, for example, is a risk factor for shedding antibiotic-resistant Escherichia coli in both horses [8] and humans [9]. In many parts of the world, antimicrobials are still used, not just in clinical settings, but as 'growth promoters' in food-producing animals, an activity banned in the European Union owing to concerns about the selection of AMR [10].…”

Disease Risk Assessments Involving Companion Animals: an Overview for 15 Selected Pathogens Taking a European Perspective

“…The ESBL-producing Enterobacteriaceae isolated in the latter study were E. coli, Klebsiella pneumoniae and Enterobacter spp., and no difference in carriage of ESBL bacteria between dogs and cats was detected. The risk factors examined in both studies included host factors, such as species or breed, age (category) and gender, healthcare related factors, such as veterinary treatments, and environmental factors concerning the nature of the premises where the animal was kept and contact with other animals (Maddox et al, 2012;Gandolfi-Descristophoris et al, 2012). In both studies, multivariable analysis showed a clear link to recent healthcare events.…”

“…There was a crosssectional study on 627 horses recruited by randomly selected veterinary clinics in the UK (Maddox et al, 2012), and one on 174 dogs and 202 cats visiting or living in randomly selected nursing homes or brought to veterinary practices for routine vaccination in Switzerland (Gandolfi-Descristophoris et al, 2012). Both studies identified cases based on faecal sampling.…”