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Home / Equine Research Bank / J Am Vet Med Assoc / Bacterial and fungal isolates from Equidae with ulcerative k...
Journal of the American Veterinary Medical Association1983; 182(6); 600-603;

Bacterial and fungal isolates from Equidae with ulcerative keratitis.

Abstract: Gram-negative bacteria were the most common microbial isolates from 38 eyes of 37 horses with ulcerative keratitis. Pseudomonas sp, Enterobacter group, and Acinetobacter sp were the most prevalent. Fungi were cultured from 15 eyes and included 7 genera, with Aspergillus sp being the most prevalent. Ten of the eyes with fungal keratitis had been treated with corticosteroids. Eleven of 38 eyes had mixed bacterial and fungal infections. Clinically, the most severe cases were those in which Aspergillus and gram-negative bacteria existed in a mixed infection. On the basis of susceptibility testing, gentamicin was highly efficacious (88.4%) against all bacterial isolates. Cephaloridine was slightly more efficacious than gentamicin against the gram-positive organisms. Only 32.3% of the gram-negative isolates were susceptible to chloramphenicol. Of the relatively small number of gram-positive organisms isolated, streptococci were more often susceptible to chloramphenicol, whereas staphylococci were more often susceptible to gentamicin.
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Publication Date: 1983-03-15 PubMed ID: 6833103
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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.

This research paper presents the findings of a study investigating the variety of bacterial and fungal infections present in the eyes of horses suffering from ulcerative keratitis. The study further explored the effectiveness of different antibiotics on these infections.

Microbial Isolates Identified

The primary focus of the research was to identify the microbial isolates from 38 eyes of 37 horses with ulcerative keratitis. The key findings include:

  • Gram-negative bacteria were identified as the most common type of microorganisms isolated from the eyes of the horses.
  • The most frequently present gram-negative bacteria were Pseudomonas sp, Enterobacter group, and Acinetobacter sp.
  • The research also identified fungal infections in 15 eyes, with seven different genera found. Aspergillus sp was the most common of these.
  • It was interesting to note that ten out of the fifteen eyes with fungal keratitis had been previously treated with corticosteroids.
  • The study also found mixed bacterial and fungal infections in eleven out of the 38 studied eyes.

Severity of Infections

Another significant area of observation in the study was the severity of the infections. Based on the clinical observations:

  • The research found that the most severe cases of infection were those where Aspergillus and gram-negative bacteria existed together as a mixed infection.

Antibiotic Efficacy

The researchers then conducted susceptibility testing to assess the efficacy of different antibiotics on the identified isolates. The key findings were:

  • Gentamicin was identified as highly effective, with an 88.4% efficacy rate against all bacterial isolates tested.
  • Cephaloridine displayed slightly higher efficacy than gentamicin against gram-positive organisms.
  • However, only 32.3% of the gram-negative isolates were found to be susceptible to the antibiotic chloramphenicol.
  • Out of the relatively less number of gram-positive organisms isolated, it was observed that streptococci were more often susceptible to chloramphenicol, whereas staphylococci showed higher susceptibility to gentamicin.

Cite This Article

APA
Moore CP, Fales WH, Whittington P, Bauer L. (1983). Bacterial and fungal isolates from Equidae with ulcerative keratitis. J Am Vet Med Assoc, 182(6), 600-603.

Publication

Journal of the American Veterinary Medical Association
ISSN: 0003-1488
NlmUniqueID: 7503067
Country: United States
Language: English
Volume: 182
Issue: 6
Pages: 600-603

Researcher Affiliations

Moore, C P
    Fales, W H
      Whittington, P
        Bauer, L

          MeSH Terms

          • Animals
          • Bacterial Infections / microbiology
          • Bacterial Infections / veterinary
          • Corneal Ulcer / microbiology
          • Corneal Ulcer / veterinary
          • Horse Diseases / microbiology
          • Horses
          • Keratitis / microbiology
          • Keratitis / veterinary
          • Mycoses / microbiology
          • Mycoses / veterinary

          Citations

          This article has been cited 14 times.
          1. Martin de Bustamante MG, Plummer CE, Caddey B, Gomez DE. The effect of topical antibiotic or antibiotic-corticosteroid treatment on the ocular surface microbiota of healthy horses. Front Microbiol 2025;16:1535095.
            doi: 10.3389/fmicb.2025.1535095pubmed: 40831630google scholar: lookup
          2. Ibrahim A, Abd-Elrasoul MAA, Sabra MS. Impact of pH modification of the empirically used tobramycin ophthalmic solution on MIC90 concentration in tears and aqueous humor of donkeys (Equus asinus). BMC Vet Res 2024 May 23;20(1):218.
            doi: 10.1186/s12917-024-04072-1pubmed: 38778405google scholar: lookup
          3. Julien ME, Shih JB, Correa Lopes B, Vallone LV, Suchodolski JS, Pilla R, Scott EM. Alterations of the bacterial ocular surface microbiome are found in both eyes of horses with unilateral ulcerative keratitis. PLoS One 2023;18(9):e0291028.
            doi: 10.1371/journal.pone.0291028pubmed: 37682941google scholar: lookup
          4. Walsh ML, Meason-Smith C, Arnold C, Suchodolski JS, Scott EM. Evaluation of the ocular surface mycobiota in clinically normal horses. PLoS One 2021;16(2):e0246537.
            doi: 10.1371/journal.pone.0246537pubmed: 33539431google scholar: lookup
          5. Tahoun A, Elnafarawy HK, Elmahallawy EK, Abdelhady A, Rizk AM, El-Sharkawy H, Youssef MA, El-Khodery S, Ibrahim HMM. Epidemiological and Molecular Investigation of Ocular Fungal Infection in Equine from Egypt. Vet Sci 2020 Sep 8;7(3).
            doi: 10.3390/vetsci7030130pubmed: 32911615google scholar: lookup
          6. Scott EM, Arnold C, Dowell S, Suchodolski JS. Evaluation of the bacterial ocular surface microbiome in clinically normal horses before and after treatment with topical neomycin-polymyxin-bacitracin. PLoS One 2019;14(4):e0214877.
            doi: 10.1371/journal.pone.0214877pubmed: 30943258google scholar: lookup
          7. Zak A, Siwinska N, Slowikowska M, Borowicz H, Ploneczka-Janeczko K, Chorbinski P, Niedzwiedz A. Conjunctival aerobic bacterial flora in healthy Silesian foals and adult horses in Poland. BMC Vet Res 2018 Aug 31;14(1):261.
            doi: 10.1186/s12917-018-1598-6pubmed: 30170594google scholar: lookup
          8. Sherman AB, Gilger BC, Berglund AK, Schnabel LV. Effect of bone marrow-derived mesenchymal stem cells and stem cell supernatant on equine corneal wound healing in vitro. Stem Cell Res Ther 2017 May 25;8(1):120.
            doi: 10.1186/s13287-017-0577-3pubmed: 28545510google scholar: lookup
          9. Guidi EE, Thomas A, Cadoré JL, Smith AB. Citrobacter freundii induced endocarditis in a yearling colt. Can Vet J 2016 Jul;57(7):767-70.
            pubmed: 27429467
          10. Hidaka S, Kobayashi M, Ando K, Fujii Y. Efficacy and safety of lomefloxacin on bacterial extraocular disease in the horse. J Vet Med Sci 2015 Jul;77(7):829-35.
            doi: 10.1292/jvms.14-0507pubmed: 25787926google scholar: lookup
          11. Reed Z, Thomasy SM, Good KL, Maggs DJ, Magdesian KG, Pusterla N, Hollingsworth SR. Equine keratomycoses in California from 1987 to 2010 (47 cases). Equine Vet J 2013 May;45(3):361-6.
            doi: 10.1111/j.2042-3306.2012.00623.xpubmed: 22943420google scholar: lookup
          12. Cullen CL, Grahn BH. Diagnostic ophthalmology. Corneal ulcer with severe secondary anterior uveitis in a pony. Can Vet J 2000 Nov;41(11):887-9.
            pubmed: 11126499
          13. Dupont C, Carrier M, Higgins R. Bacterial and fungal flora in healthy eyes of birds of prey. Can Vet J 1994 Nov;35(11):699-701.
            pubmed: 7866959
          14. Aho R, Tala M, Kivalo M. Mycotic keratitis in a horse caused by Aspergillus fumigatus. The first reported case in Finland. Acta Vet Scand 1991;32(3):373-6.
            doi: 10.1186/BF03546967pubmed: 1814187google scholar: lookup
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