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Home / Equine Research Bank / Vet Ophthalmol / Equine ulcerative keratitis in Belgium: Associated bacterial...
Veterinary ophthalmology2022; 25(5); 326-337; doi: 10.1111/vop.12985

Equine ulcerative keratitis in Belgium: Associated bacterial isolates and in vitro antimicrobial resistance in 200 eyes.

Abstract: To describe bacterial isolates and associated antibiotic resistance from horses with ulcerative keratitis in Belgium. Methods: Medical records from horses with ulcerative keratitis presented to the ophthalmology service of the Veterinary teaching hospital of Liege, Belgium, between 2014 and 2021 were evaluated. Bacterial isolates were identified and VITEK® 2 (Biomérieux) provided antimicrobial susceptibility testing and resistance detection. Results: Two hundred eyes of 196 horses were sampled. Ninety-seven eyes had a positive bacterial culture (48.5%) and 139 bacterial isolates were identified. Staphylococcus (63/139: 45.3%) and Streptococcus (33/139: 23.7%) were the most frequent genus isolated. Staphylococcus aureus (21/139: 15.1%) was the most frequent species isolated of which half were methicillin-resistant (MRS). Streptococcus equi subsp. zooepidemicus (19/139: 13.7%) was the second most identified bacterial isolate. Only two Pseudomonas species were isolated (2/139: 1.4%). The overall resistance of all bacterial isolates against chloramphenicol (12.4%) and fluoroquinolones (14.3%) was low. Resistance against tobramycin, polymyxin B, gentamicin, fusidic acid, tetracycline, and neomycin ranged from 40.8% to 58.6%. When separating the MRS from the other staphylococci, a significant difference was noted in percentage of resistance to gentamicin (p = .00026) and tetracycline (p = .00015). MRS were highly resistant to gentamicin (75%) and tetracycline (100%), whereas the remaining staphylococci were significantly less resistant to gentamicin (17%) and tetracycline (40.4%). Conclusions: Although Pseudomonas species has been rarely cultured, our results are roughly consistent with previous studies. Multiple drug resistance was high and resistance to first-choice antibiotics in ulcerative keratitis was noted. These results warrant continued monitoring of susceptibility profile.
© 2022 American College of Veterinary Ophthalmologists.
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Publication Date: 2022-03-28 PubMed ID: 35343046DOI: 10.1111/vop.12985Google Scholar: Lookup
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  • Journal Article

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 investigates the bacteria responsible for causing ulcerative keratitis in horses in Belgium, as well as the associated antibiotic resistance. The results revealed a high percentage of drug resistance, and the bacteria Staphylococcus and Streptococcus were the most commonly isolated.

Research Approach and Methods

  • The medical records of horses that showed signs of ulcerative keratitis and were presented to the ophthalmology service of the Veterinary teaching hospital of Liege, Belgium between 2014 and 2021 were considered for the research.
  • From these records, 200 horse eyes were sampled for investigation.
  • The bacterial isolates were identified using traditional culture methods and the VITEK 2 system from Biomérieux was used to test for antimicrobial susceptibility and to detect antibiotic resistance.

Research Findings

  • Of the 200 eyes sampled, 97 (48.5%) yielded a positive bacterial culture, with a total of 139 bacterial isolates being identified.
  • Staphylococcus and Streptococcus were the most common genus of bacteria isolated, at 45.3% and 23.7% respectively.
  • The most frequently isolated species was Staphylococcus aureus (15.1%), with half of these isolates showing methicillin resistance (MRS)
  • After S. aureus, Streptococcus equi subsp. zooepidemicus was the second most commonly identified bacterial isolate (13.7%).
  • Only two Pseudomonas species were isolated, forming a mere 1.4% of the total.

Antibiotic Resistance

  • The overall resistance to chloramphenicol and fluoroquinolones was reasonably low, at 12.4% and 14.3% respectively.
  • Resistance rates were higher for tobramycin, polymyxin B, gentamicin, fusidic acid, tetracycline, and neomycin, with rates ranging between 40.8% and 58.6%.
  • Notably, methicillin-resistant Staphylococci showed significantly higher resistance to gentamicin and tetracycline compared to other Staphylococci. 75% of these isolates were resistant to gentamicin and 100% were resistant to tetracycline, compared to 17% and 40.4% respectively in other Staphylococci.

Conclusion and Implications

  • The findings of the study echo those of previous research. The low rate of Pseudomonas species isolation was surprising, but the high rates of antibiotic resistance, and specifically the resistance to first-choice antibiotics for ulcerative keratitis, is a cause for concern.
  • The researchers recommend ongoing monitoring of the susceptibility profile of these bacteria to track changes over time and ensure that effective treatment protocols can be maintained.

Cite This Article

APA
Vercruysse EM, Narinx FP, Rives ACM, Sauvage AC, Grauwels MF, Monclin SJ. (2022). Equine ulcerative keratitis in Belgium: Associated bacterial isolates and in vitro antimicrobial resistance in 200 eyes. Vet Ophthalmol, 25(5), 326-337. https://doi.org/10.1111/vop.12985

Publication

Veterinary ophthalmology
ISSN: 1463-5224
NlmUniqueID: 100887377
Country: England
Language: English
Volume: 25
Issue: 5
Pages: 326-337

Researcher Affiliations

Vercruysse, Eline M
  • Ophthalmology Service, Veterinary Teaching Hospital, University of Liège, Liège, Belgium.
Narinx, Florine P
  • Ophthalmology Service, Veterinary Teaching Hospital, University of Liège, Liège, Belgium.
Rives, Albane C M
  • Department of Veterinary Management of Animal Resources, Veterinary Teaching Hospital, University of Liège, Liège, Belgium.
Sauvage, Aurélie C
  • Ophthalmology Service, Veterinary Teaching Hospital, University of Liège, Liège, Belgium.
Grauwels, Magda F
  • Ophthalmology Service, Veterinary Teaching Hospital, University of Liège, Liège, Belgium.
Monclin, Sébastien J
  • Ophthalmology Service, Veterinary Teaching Hospital, University of Liège, Liège, Belgium.

MeSH Terms

  • Animals
  • Anti-Bacterial Agents / pharmacology
  • Anti-Bacterial Agents / therapeutic use
  • Belgium / epidemiology
  • Corneal Ulcer / drug therapy
  • Corneal Ulcer / epidemiology
  • Corneal Ulcer / veterinary
  • Drug Resistance, Bacterial
  • Gentamicins
  • Horses
  • Hospitals, Animal
  • Hospitals, Teaching
  • Microbial Sensitivity Tests / veterinary
  • Staphylococcus
  • Tetracyclines

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Citations

This article has been cited 7 times.
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  2. Heun F, Meißner J, Schieder AK, Ohnesorge B, Busse C. Pantoea agglomerans in Equine Ulcerative Keratitis: Prevalence and Comparative Efficacy of Four Topical Antiseptics. Vet Ophthalmol 2026 Jan;29(1):e70044.
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