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Veterinary ophthalmology2011; 14(3); 195-199; doi: 10.1111/j.1463-5224.2010.00867.x

Conjunctival bacterial and fungal flora in healthy horses in the UK.

Abstract: To describe the bacterial and fungal flora of the normal conjunctiva of horses in the UK; to determine the effect of horse age, sex, geographic location, and housing on this flora; and to determine the most appropriate antimicrobial drug(s) for prophylactic treatment of corneal ulcers. Methods: A total of 60 adult healthy horses were studied. Methods: Swabs of the conjunctiva were obtained from 60 horses housed in two locations within the UK. Specimens were cultured for aerobic bacteria and fungi, and sensitivity against six ophthalmic antimicrobials assessed. The effect of age, sex, location and housing on the frequency of microbial isolation was evaluated. Results: Fifty-four bacterial isolates, representing thirteen genera of bacteria were cultured from 31 (52%) horses. The most frequently isolated bacterial species was Acinetobacter sp (17/32 horses). The majority of isolates (28/54: 52%) were gram-positive. Three genera of fungi (Mucor, Absidia and Aspergillus spp) were isolated from eight (13%) horses. There was no significant effect of geographic location, sex, age or housing on frequency of microbial isolation. Horses from which gram-negative bacteria were isolated were significantly older than horses from which gram-positive bacteria were isolated. High efficacy (greater than 90% of isolates sensitive in vitro) was displayed by chloramphenicol, gentamicin and tetracycline. Conclusions: The microbial species isolated are comparable with studies performed in other countries, although the frequency of Acinetobacter isolation was higher which may reflect a geographic difference. The topical antimicrobials gentamicin and chloramphenicol are appropriate first line antimicrobials for empirical treatment of corneal ulcers in the UK.
© 2011 American College of Veterinary Ophthalmologists.
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Publication Date: 2011-04-28 PubMed ID: 21521444DOI: 10.1111/j.1463-5224.2010.00867.xGoogle 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.

This research study examines the bacterial and fungal flora of healthy horse eyes in the UK to understand the effect of various factors like age, sex, geography, and housing, and to prescribe suitable antimicrobial drugs for treating corneal ulcers.

Research Methodology

  • The study was conducted on a group of 60 healthy adult horses from two different locations in the UK.
  • Swabs were taken from the conjunctiva, the membrane that covers the front of the eye and lines the inside of the eyelids, of these horses.
  • These samples were then cultured for aerobic bacteria and fungi, which then helped in identifying possible organisms present.
  • The researchers also assessed sensitivity against six ophthalmic antimicrobials, which are drugs used to treat eye infections.
  • The research analyzed the influence of factors such as age, sex, location, and housing on the frequency of microbial isolation.

Results of the Study

  • Fifty-four bacterial isolates, representing thirteen different genera of bacteria were cultured from 31 horses, making up 52% of the total subjects.
  • The most frequently isolated bacterial species was Acinetobacter sp, which was found in roughly half of the horses.
  • On further classification, 52% of these bacteria were found to be gram-positive.
  • Three genera of fungi – Mucor, Absidia and Aspergillus spp – were identified from 13% of the horses.
  • The study reported no significant impact of geographic location, sex, age or housing on the frequency of microbial isolation.
  • Horses from which gram-negative bacteria were isolated were found to be significantly older than those from which gram-positive bacteria were isolated.
  • Three drugs – chloramphenicol, gentamicin and tetracycline – displayed high efficacy, with more than 90% of isolates being sensitive to them in vitro.

Study Conclusions

  • The microbial species isolated from this study were found to be similar to those reported in studies conducted in other countries.
  • The higher frequency of Acinetobacter isolation could possibly indicate a geographic difference in bacterial flora of horse conjunctiva.
  • The study also concluded that the topical antimicrobials gentamicin and chloramphenicol are effective as the first line of treatment for corneal ulcers in horses in the UK.

Cite This Article

APA
Johns IC, Baxter K, Booler H, Hicks C, Menzies-Gow N. (2011). Conjunctival bacterial and fungal flora in healthy horses in the UK. Vet Ophthalmol, 14(3), 195-199. https://doi.org/10.1111/j.1463-5224.2010.00867.x

Publication

Veterinary ophthalmology
ISSN: 1463-5224
NlmUniqueID: 100887377
Country: England
Language: English
Volume: 14
Issue: 3
Pages: 195-199

Researcher Affiliations

Johns, Imogen C
  • Equine Referral Hospital, Veterinary Clinical Science, Royal Veterinary College, Hawkshead Lane, North Mymms, Herts AL9 7TA, UK. ijohns@rvc.ac.uk
Baxter, Katherine
    Booler, Helen
      Hicks, Charlotte
        Menzies-Gow, Nicola

          MeSH Terms

          • Aging
          • Animals
          • Anti-Bacterial Agents / pharmacology
          • Bacteria / classification
          • Bacteria / drug effects
          • Bacteria / isolation & purification
          • Conjunctiva / microbiology
          • Drug Resistance, Bacterial
          • Female
          • Fungi / classification
          • Fungi / isolation & purification
          • Horses / microbiology
          • Housing, Animal
          • Male
          • Sex Characteristics
          • United Kingdom

          Citations

          This article has been cited 24 times.
          1. Khalid E, Tartor YH, Ammar AM, Abdelaziz R, Mahmmod Y, Abdelkhalek A. Controlling drug-resistant bacteria in Arabian horses: bacteriophage cocktails for treating wound infections. Front Vet Sci 2025;12:1609955.
            doi: 10.3389/fvets.2025.1609955pubmed: 41169678google scholar: lookup
          2. 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
          3. 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.
            doi: 10.1111/vop.70044pubmed: 40557447google scholar: lookup
          4. Hosny OH, Abd-Elkareem M, Ali MM, Ahmed AF. Advanced platelet-rich fibrin promotes healing of induced corneal ulcer in donkeys (Equus asinus). Sci Rep 2023 Dec 9;13(1):21824.
            doi: 10.1038/s41598-023-48933-5pubmed: 38071242google scholar: lookup
          5. 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
          6. Torres LEC, Florez CO, Oliveira JG, Vieira GD, Ribeiro IS, Keller KM, Leme FOP, Fantini P, Maranhão RPA. Antimicrobial Activity of Plasma Rich in Platelets (PRP) on the Ocular Microbiota of Healthy Horses from Minas Gerais: In Vitro Study. Vet Med Int 2023;2023:2407768.
            doi: 10.1155/2023/2407768pubmed: 37622165google scholar: lookup
          7. Mo PM, Picard J, Gummow B. The conjunctival fungal microflora of horses in a North Queensland tropical environment and their in vitro susceptibilities to antifungal agents. Vet Res Commun 2023 Sep;47(3):1641-1651.
            doi: 10.1007/s11259-023-10119-9pubmed: 37022654google scholar: lookup
          8. Aftab G, Arfaee F, Asghari A, Zahraei Salehi T. The evaluation of normal ocular parameters in two breeds of hedgehogs. Vet Med Sci 2023 Mar;9(2):738-743.
            doi: 10.1002/vms3.1055pubmed: 36791281google scholar: lookup
          9. Fernández-Garayzábal JF, LaFrentz S, Casamayor A, Abarca E, Mohammed HH, Cuming RS, Arias CR, Domínguez L, Vela AI. Corynebacterium conjunctivae: A New Corynebacterium Species Isolated from the Ocular Surface of Healthy Horses. Animals (Basel) 2022 Jul 18;12(14).
            doi: 10.3390/ani12141827pubmed: 35883374google scholar: lookup
          10. Santibáñez R, Lara F, Barros TM, Mardones E, Cuadra F, Thomson P. Ocular Microbiome in a Group of Clinically Healthy Horses. Animals (Basel) 2022 Apr 7;12(8).
            doi: 10.3390/ani12080943pubmed: 35454190google scholar: lookup
          11. Fraczkowska K, Zak-Bochenek A, Siwinska N, Rypula K, Ploneczka-Janeczko K. Aerobic Commensal Conjunctival Microflora in Healthy Donkeys. Animals (Basel) 2022 Mar 17;12(6).
            doi: 10.3390/ani12060756pubmed: 35327153google scholar: lookup
          12. Tahoun A, Elnafarawy HK, El-Sharkawy H, Rizk AM, Alorabi M, El-Shehawi AM, Youssef MA, Ibrahim HMM, El-Khodery S. The Prevalence and Molecular Biology of Staphylococcus aureus Isolated from Healthy and Diseased Equine Eyes in Egypt. Antibiotics (Basel) 2022 Feb 10;11(2).
            doi: 10.3390/antibiotics11020221pubmed: 35203823google scholar: lookup
          13. Nardi S, Puccini Leoni F, Monticelli V, Ebani VV, Bertelloni F, Marzoni M, Mancianti F, Citi S, Barsotti G. Tear Production, Intraocular Pressure, Ultrasound Biometric Features and Conjunctival Flora Identification in Clinically Normal Eyes of Two Italian Breeds of Chicken (Gallus gallus domesticus). Animals (Basel) 2021 Oct 17;11(10).
            doi: 10.3390/ani11102987pubmed: 34680006google scholar: lookup
          14. 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
          15. Vale AP, Leggett B, Smyth D, Leonard F. Challenges in the veterinary microbiology diagnostic laboratory: a novel Acinetobacter species as presumptive cause for feline unilateral conjunctivitis. Access Microbiol 2020;2(6):acmi000118.
            doi: 10.1099/acmi.0.000118pubmed: 32974584google scholar: lookup
          16. 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
          17. Lores M, Rakestraw P, De Rijck M, Yarbrough T. Use of autologous fascia lata graft to repair a complex corneal ulcer in a mare. Ir Vet J 2020;73:7.
            doi: 10.1186/s13620-020-00160-4pubmed: 32391144google scholar: lookup
          18. Mustikka MP, Grönthal TSC, Pietilä EM. Equine infectious keratitis in Finland: Associated microbial isolates and susceptibility profiles. Vet Ophthalmol 2020 Jan;23(1):148-159.
            doi: 10.1111/vop.12701pubmed: 31364808google scholar: lookup
          19. 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
          20. 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
          21. Galera PD, Brooks DE. Optimal management of equine keratomycosis. Vet Med (Auckl) 2012;3:7-17.
            doi: 10.2147/VMRR.S25013pubmed: 30155429google scholar: lookup
          22. Lupo A, Haenni M, Madec JY. Antimicrobial Resistance in Acinetobacter spp. and Pseudomonas spp. Microbiol Spectr 2018 Jun;6(3).
            doi: 10.1128/microbiolspec.ARBA-0007-2017pubmed: 30101740google scholar: lookup
          23. Bonelli F, Barsotti G, Attili AR, Mugnaini L, Cuteri V, Preziuso S, Corazza M, Preziuso G, Sgorbini M. Conjunctival bacterial and fungal flora in clinically normal sheep. Vet Rec Open 2014;1(1):e000017.
            doi: 10.1136/vropen-2013-000017pubmed: 26392873google scholar: lookup
          24. Hellander-Edman A, Makdoumi K, Mortensen J, Ekesten B. Corneal cross-linking in 9 horses with ulcerative keratitis. BMC Vet Res 2013 Jun 26;9:128.
            doi: 10.1186/1746-6148-9-128pubmed: 23803176google scholar: lookup
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