Antimicrobial resistance in clinical bacterial isolates from horses in the UK



Isgren, Cajsa M, Williams, Nicola J, Fletcher, Owen D, Timofte, Dorina ORCID: 0000-0002-7261-738X, Newton, Richard J, Maddox, Thomas W, Clegg, Peter D ORCID: 0000-0003-0632-0032 and Pinchbeck, Gina L ORCID: 0000-0002-5671-8623
(2022) Antimicrobial resistance in clinical bacterial isolates from horses in the UK. EQUINE VETERINARY JOURNAL, 54 (2). pp. 390-414.

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Abstract

<h4>Background</h4>Surveillance of antimicrobial resistance (AMR) in horses is important to aid empirical treatment decisions and highlight emerging AMR threats.<h4>Objective</h4>To describe the AMR patterns of common groups of bacteria from clinical submissions from horses in the UK during 2018, and to determine how this varies by sample site and type of submitting veterinary practice.<h4>Study design</h4>Prospective observational study.<h4>Methods</h4>All data on bacterial culture and subsequent antimicrobial susceptibility testing (AST) collected in 2018 from six large equine diagnostic laboratories were included. Resistance patterns were analysed including resistance to 1 or 2 antimicrobial classes, multidrug resistance (MDR), extensively drug resistant (XDR), resistance to highest priority critically important antimicrobials and isolates where there was no readily available treatment for adult horses in the UK. Submitting practices were classified according to whether they treated referral cases or not (first opinion). Comparisons between proportions and resistance for each bacterial group and sample site was performed using Chi-squared (or Fisher's exact test).<h4>Results</h4>A total of 6,018 bacterial isolates from 4,038 diagnostic submissions were included from respiratory (n = 1555), urogenital (n = 1,010), skin/hair/wound/abscess (n = 753), surgical site infection (SSI) /catheter-related-infection (CRI) /orthopaedic infections (n = 347) and unknown/'other' submissions (n = 373). There were 2,711 Gram-negative isolates and 3,307 Gram-positive isolates. Prevalence of MDR for E. coli was 31.7%, Staphylococcus spp. 25.3% and > 25% for the majority of bacterial isolates from SSI/CRI/orthopaedic submissions. For Enterococcus spp. there was no readily available treatment for adult horses in the UK in 30.2% of positive submissions. MDR was significantly higher from referral hospital than first opinion submissions for the majority of pathogens (except Actinobacillus spp. and Pasteurella spp. and β-haemolytic Streptococcus spp.).<h4>Main limitations</h4>Since culture and susceptibility results are not systematic analyses based on harmonised methods, selection bias could impact the findings.<h4>Conclusions</h4>Ongoing surveillance is essential to understand emerging patterns of resistance. MDR is high in SSI/CRI/orthopaedic infections, which is important for hospital biosecurity and guiding treatment decisions. Harmonisation of diagnostic procedures and interpretation of results amongst veterinary laboratories will improve AMR surveillance and data comparison among laboratories.

Item Type: Article
Uncontrolled Keywords: antimicrobial susceptibility testing, antimicrobial resistance, equine pathogens, intrinsic resistance, multidrug resistance, surgical site infection
Divisions: Faculty of Health and Life Sciences
Faculty of Health and Life Sciences > Institute of Infection, Veterinary and Ecological Sciences
Faculty of Health and Life Sciences > Institute of Life Courses and Medical Sciences
Depositing User: Symplectic Admin
Date Deposited: 27 Apr 2021 12:40
Last Modified: 18 Jan 2023 22:50
DOI: 10.1111/evj.13437
Related URLs:
URI: https://livrepository.liverpool.ac.uk/id/eprint/3120739