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Home / Equine Research Bank / Vet Ophthalmol / Changes in antimicrobial resistance patterns of ocular surfa...
Veterinary ophthalmology2020; 23(6); 950-956; doi: 10.1111/vop.12827

Changes in antimicrobial resistance patterns of ocular surface bacteria isolated from horses in the UK: An eight-year surveillance study (2012-2019).

Abstract: To identify temporal changes in antimicrobial resistance of ocular surface bacteria isolated from clinically symptomatic equine eyes in the South West of the UK. Methods: Retrospective. Methods: Clinical and laboratory records of horses treated for suspected bacterial ocular surface disease (ulcerative and non-ulcerative) at a single facility between January 2011 and December 2019 were reviewed. Cases were included if they underwent ocular surface sampling, aerobic bacterial culture, and antimicrobial susceptibility testing. Cases were split into two time periods based on when sampling occurred: "early" (2012-2015) and "late" (2016-2019) to enable identification of temporal trends in resistance to chloramphenicol, gentamicin, fusidic acid, neomycin, cloxacillin, ofloxacin, and polymyxin B. Results: A total of 125 samples from 110 horses were included in analyses. Culture-positive isolates were identified in 76/110 (60.8%) samples. Principal isolates included Staphylococci spp. (n = 45; 64.3%), Streptococci spp. (n = 14; 20%), and Enterobacter spp. (n = 11; 15.7%). There was a significant increase in resistance to chloramphenicol over time (P = .007) and a decrease in resistance to ofloxacin that approached significance (P = .059). Chloramphenicol (100%) and gentamicin (85.7%) had the highest overall in-vitro efficacy during the early and late periods, respectively. There was no significant difference in the type of bacteria isolated across the two time periods. Conclusions: These results suggest a potential increase in resistance to chloramphenicol among bacteria isolated from the ocular surface of horses in the South West UK, reinforcing the value of surveillance to guide the empirical use of antimicrobials.
© 2020 American College of Veterinary Ophthalmologists.
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Publication Date: 2020-09-22 PubMed ID: 32961021DOI: 10.1111/vop.12827Google Scholar: Lookup
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Summary

This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.

The research article presents the findings of an eight-year surveillance study aimed at identifying the changes in antimicrobial resistance in bacteria isolated from the eyes of horses in the South West of the UK.

Study Methodology

  • The research is a retrospective review of clinical and laboratory records of horses treated for suspected bacterial ocular surface diseases between January 2011 and December 2019.
  • The study included cases that underwent procedures like ocular surface sampling, aerobic bacterial culture, and antimicrobial susceptibility testing.
  • For the purpose of identifying temporal trends in antibacterial resistance, the cases were divided into two periods: early (2012-2015), and late (2016-2019).
  • The investigators focused on the response of the bacterial isolates to several antibiotics, including chloramphenicol, gentamicin, fusidic acid, neomycin, cloxacillin, ofloxacin, and polymyxin B.

Results

  • A total of 125 samples from 110 horses were examined for the study. Of these, culture-positive isolates were identified in 76 (60.8%) samples.
  • The most common bacteria isolated from the samples were Staphylococci spp. (found in 64.3% samples), Streptococci spp. (20%), and Enterobacter spp. (15.7%).
  • The study recorded a significant increase in resistance to chloramphenicol over time. However, the decrease in resistance to ofloxacin was not significant.
  • Chloramphenicol proved to have the highest overall in-vitro efficacy (100%) in the early period, while gentamicin showed the highest efficacy (85.7%) in the late period.
  • There was no significant difference in the type of bacteria isolated between the two time periods.

Conclusions

  • The research suggests a potential increase in resistance to chloramphenicol among bacteria isolated from the ocular surface of horses in the South West UK.
  • The study also highlights the importance of continual surveillance to guide the empirical use of antimicrobials, considering the evolving antibiotic resistance patterns.

Cite This Article

APA
Chalder RH, Knott T, Rushton JO, Nikolic-Pollard D. (2020). Changes in antimicrobial resistance patterns of ocular surface bacteria isolated from horses in the UK: An eight-year surveillance study (2012-2019). Vet Ophthalmol, 23(6), 950-956. https://doi.org/10.1111/vop.12827

Publication

Veterinary ophthalmology
ISSN: 1463-5224
NlmUniqueID: 100887377
Country: England
Language: English
Volume: 23
Issue: 6
Pages: 950-956

Researcher Affiliations

Chalder, Ria H
  • The Animal Health Trust, Kentford, UK.
Knott, Tim
  • Rowe Referrals, Bradley Stoke, UK.
Rushton, James O
  • Rowe Referrals, Bradley Stoke, UK.
Nikolic-Pollard, Danica
  • The Animal Health Trust, Kentford, UK.

MeSH Terms

  • Animals
  • Anti-Bacterial Agents / pharmacology
  • Bacteria / drug effects
  • Bacteria / isolation & purification
  • Drug Resistance, Bacterial
  • Eye Infections, Bacterial / microbiology
  • Eye Infections, Bacterial / veterinary
  • Female
  • Health Surveys
  • Horse Diseases / microbiology
  • Horses
  • Male
  • Retrospective Studies
  • United Kingdom

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Citations

This article has been cited 2 times.
  1. Hardefeldt L, Thomas K, Page S, Norris J, Browning G, El Hage C, Stewart A, Gilkerson J, Muscatello G, Verwilghen D, van Galen G, Bauquier J, Cuming R, Reynolds B, Whittaker C, Wilkes E, Clulow J, Burden C, Begg L. Antimicrobial prescribing guidelines for horses in Australia. Aust Vet J 2025 Dec;103(12):781-889.
    doi: 10.1111/avj.70003pubmed: 40903020google scholar: lookup
  2. Amiriantz S, Hoummady S, Jarousse E, Roudeix S, Philippon T. Investigating the Bactericidal Activity of an Ocular Solution Containing EDTA, Tris, and Polysorbate 80 and Its Impact on the In Vitro Efficacy of Neomycin Sulfate against Staphylococcus aureus: A Preliminary Study. Antibiotics (Basel) 2024 Jun 30;13(7).
    doi: 10.3390/antibiotics13070611pubmed: 39061293google scholar: lookup
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