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Veterinary surgery : VS2020; 49(7); 1283-1291; doi: 10.1111/vsu.13474

Antimicrobial susceptibility of bacterial isolates from 33 thoroughbred horses with arytenoid chondropathy (2005-2019).

Abstract: To describe the prevalence and antimicrobial susceptibility of bacterial isolates cultured from surgical specimens of infected arytenoid cartilage and granulomas. Methods: Retrospective cohort study. Methods: Thirty-three thoroughbred horses. Methods: Hospital records were retrieved for all horses admitted to a referral hospital for arytenoid chondropathy surgery that had samples submitted for culture and sensitivity between 2005 and 2019. Descriptive analyses were performed. Results: In total, 56 bacterial isolates were obtained. Gram-positive bacteria (58%), Gram-negative bacteria (54%), and anaerobes (33%) were cultured from samples. Fifty-eight percent of horses had multiple bacteria isolated. Streptococcus spp were the most common (32%), followed by Enterobacteriaceae (13%). Bacterial isolates were sensitive to ceftiofur (83%), followed by ampicillin (64%), tetracycline (48%), enrofloxacin (45%), trimethoprim-sulfamethoxazole (41%), and gentamicin (18%). Multidrug resistance (MDR) was present in 44% of bacterial isolates. Conclusions: A wide variety of bacteria was cultured, providing evidence that secondary opportunistic infection by common respiratory bacteria is likely a factor in arytenoid chondropathy. Multidrug resistance was higher than what has been previously reported in equine respiratory samples. Trimethoprim-sulfamethoxazole had low effectiveness. Conclusions: Because culture and sensitivity testing is not available in the diagnosis of mild to moderate arytenoid chondropathy, the information from this study may allow for more targeted broad-spectrum antimicrobial treatment to limit disease progression when the disease is first identified. The antimicrobial susceptibilities and MDR found in this study emphasize the importance of following current antimicrobial guidelines and highlight the requirement for surgical intervention rather than continued medical treatment in cases that do not resolve with initial antimicrobial therapy.
Publication Date: 2020-08-07 PubMed ID: 32767594DOI: 10.1111/vsu.13474Google Scholar: Lookup
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  • Journal Article

Summary

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This research paper explores the types and prevalence of bacteria found in infected arytenoid cartilage in thoroughbred horses, as well as the effectiveness of different antibiotics on these bacteria. The paper also emphasizes the importance of targeted treatment to limit disease progression and suggests changes to the approach in medical care if initial treatment is unsuccessful.

Study Methodology

  • The study is retrospective and analyses hospital records of thoroughbred horses that were admitted for arytenoid chondropathy surgery and had samples submitted for culture and sensitivity from 2005 to 2019.
  • Descriptive analyses of the data were performed.
  • The report studied samples from 33 horses; from these samples, 56 bacterial isolates were obtained.

Results Analysis

  • The bacterial isolates included a mix of Gram-positive bacteria (58%), Gram-negative bacteria (54%), and anaerobes (33%).
  • More than half of the horses had multiple bacteria isolated.
  • The most common bacteria found were Streptococcus spp (32%), followed by Enterobacteriaceae (13%).
  • The bacterial isolates exhibited the highest sensitivity to the antibiotic ceftiofur (83%), followed by ampicillin (64%), tetracycline (48%), enrofloxacin (45%), trimethoprim-sulfamethoxazole (41%), and gentamicin (18%).
  • Significantly, Multidrug resistance (MDR) was observed in 44% of the bacterial isolates.

Conclusions and Implications

  • The wide variety of bacteria cultured gives evidence that secondary opportunistic infection by common respiratory bacteria are likely a factor to consider in arytenoid chondropathy.
  • The high level of multidrug resistance found in these bacteria was higher than what has been previously reported in equine respiratory samples.
  • Trimethoprim-sulfamethoxazole had low effectiveness against the bacterial isolates in this study.
  • The findings of this study could potentially help in providing more targeted broad-spectrum antimicrobial treatment, especially when the disease is first identified.
  • Results from this study emphasize the importance of adhering to current antimicrobial guidelines and also highlights the need for surgical intervention rather than continued medical treatment in cases that do not resolve with initial antimicrobial therapy.

Cite This Article

APA
Johnston GCA, Lumsden JM. (2020). Antimicrobial susceptibility of bacterial isolates from 33 thoroughbred horses with arytenoid chondropathy (2005-2019). Vet Surg, 49(7), 1283-1291. https://doi.org/10.1111/vsu.13474

Publication

ISSN: 1532-950X
NlmUniqueID: 8113214
Country: United States
Language: English
Volume: 49
Issue: 7
Pages: 1283-1291

Researcher Affiliations

Johnston, Georgina C A
  • School of Veterinary Science, The University of Queensland, Gatton, Queensland, Australia.
Lumsden, Jonathan M
  • Randwick Equine Centre, Sydney, New South Wales, Australia.

MeSH Terms

  • Animals
  • Anti-Bacterial Agents / pharmacology
  • Arytenoid Cartilage / pathology
  • Bacteria / drug effects
  • Cartilage Diseases / drug therapy
  • Cartilage Diseases / microbiology
  • Cartilage Diseases / veterinary
  • Drug Resistance, Bacterial
  • Gram-Negative Bacteria
  • Horse Diseases / drug therapy
  • Horse Diseases / microbiology
  • Horses
  • Microbial Sensitivity Tests / veterinary
  • Retrospective Studies

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Citations

This article has been cited 3 times.
  1. Zhao Y, Zhu Y, Liu B, Mi J, Li N, Zhao W, Wu R, Holyoak GR, Li J, Liu D, Zeng S, Wang Y. Antimicrobial Susceptibility of Bacterial Isolates from Donkey Uterine Infections, 2018-2021. Vet Sci 2022 Feb 5;9(2).
    doi: 10.3390/vetsci9020067pubmed: 35202320google scholar: lookup
  2. 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
  3. Jasim SA, Mohammed JS, Roopashree R, Alshahrani MY, Sharma A, Sharma A, Asliddin S, Beig M. Unraveling the global landscape of Elizabethkingia antibiotic resistance: A systematic review and meta-analysis. PLoS One 2025;20(5):e0323313.
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