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Journal of the American Veterinary Medical Association2013; 242(7); 977-983; doi: 10.2460/javma.242.7.977

Uterine bacterial isolates from mares and their resistance to antimicrobials: 8,296 cases (2003-2008).

Abstract: To describe bacteria isolated from reproductive tracts of mares and to examine the extent and patterns of resistance to antimicrobials commonly used for treatment of endometritis. Methods: Retrospective case series. Methods: 8,296 uterine swab, lavage, or biopsy samples obtained between January 2003 and December 2008 from 7,665 horses in central Florida. Methods: Results of bacterial culture and antimicrobial susceptibility testing were obtained for uterine swab, lavage, and biopsy samples collected from mares undergoing a routine breeding examination or examined because of a reproductive disorder. Bacterial organisms were identified by means of standard techniques, and proportions of samples resistant to various antimicrobials were determined. Results: At least 95% of samples (n = 1,451) were collected with uterine swabs. Potentially pathogenic organisms were cultured from 2,576 (31%) samples, with Escherichia coli (n = 729 [29%]) and β-hemolytic Streptococcus equi subsp zooepidemicus (733 [28%]) being most common. Resistance to antimicrobials changed over time for E coli, S equi subsp zooepidemicus, and Enterobacteriaceae isolates. Overall, E coli was most resistant to trimethoprim-sulfonamide and ampicillin and least to amikacin and enrofloxacin. For S equi subsp zooepidemicus, resistance was greatest to oxytetracycline and enrofloxacin and least to ceftiofur and ticarcillin with or without clavulanic acid. Inflammatory response was greater for S equi subsp zooepidemicus. Conclusions: E coli and S equi subsp zooepidemicus were the most common pathogens recovered from uterine samples, with S equi subsp zooepidemicus more commonly associated with inflammation. Antimicrobials most commonly used empirically to treat endometritis are appropriate on the basis of these data. However, as antimicrobial resistance changes over time, susceptibility assays should aid antimicrobial selection.
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Publication Date: 2013-03-23 PubMed ID: 23517211DOI: 10.2460/javma.242.7.977Google 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 paper investigated the types of bacteria found in the reproductive tracts of mares (female horses) and how resistant these bacteria are to different antimicrobials commonly used for treating uterine inflammation. The study found that E. coli and Streptococcus equi subsp zooepidemicus were the most prevalent bacteria, but their resistance to antimicrobials varied over time, therefore suggesting the importance of ongoing testing to guide treatment selections.

Study Methodology

  • The study was a retrospective case series and it involved analyzing data obtained from 8,296 uterine swab, lavage, or biopsy samples. These samples were collected between January 2003 and December 2008 from 7,665 horses in central Florida.
  • Samples were collected from mares that were either undergoing a routine breeding examination or those examined due to reproductive issues.
  • The researchers used standard techniques to identify the bacterial organisms present in these samples.
  • They also determined the proportions of samples that showed resistance to various antimicrobials.

Research Findings

  • A significant majority (at least 95%) of the samples were taken using uterine swabs.
  • Potentially pathogenic organisms were cultured from 2,576 samples (31%), with Escherichia coli and β-hemolytic Streptococcus equi subsp zooepidemicus being the most common bacteria.
  • The study found that antimicrobial resistance patterns for these bacteria varied over time.
  • E. coli showed high resistance to trimethoprim-sulfonamide and ampicillin, but low resistance to amikacin and enrofloxacin.
  • For S. equi subsp zooepidemicus, resistance was greatest to oxytetracycline and enrofloxacin and least to ceftiofur and ticarcillin with or without clavulanic acid.
  • S. equi subsp zooepidemicus caused a more significant inflammatory response than other microbial species.

Study Conclusions

  • This research informs us that E. coli and S. equi subsp zooepidemicus are the most common bacterial pathogens in the uterine samples, with S. equi subsp zooepidemicus more commonly associated with inflammation.
  • The antimicrobials used empirically to treat endometritis appear appropriate given the current data on the resistance patterns.
  • However, because these antimicrobial resistance patterns can change over time, it is beneficial to conduct regular susceptibility assays to better select the most effective antimicrobials for treatment.

Cite This Article

APA
Davis HA, Stanton MB, Thungrat K, Boothe DM. (2013). Uterine bacterial isolates from mares and their resistance to antimicrobials: 8,296 cases (2003-2008). J Am Vet Med Assoc, 242(7), 977-983. https://doi.org/10.2460/javma.242.7.977

Publication

Journal of the American Veterinary Medical Association
ISSN: 1943-569X
NlmUniqueID: 7503067
Country: United States
Language: English
Volume: 242
Issue: 7
Pages: 977-983

Researcher Affiliations

Davis, Heather A
  • Department of Anatomy, Physiology, and Pharmacology, College of Veterinary Medicine, Auburn University, Auburn, AL 36832, USA. davish1@auburn.edu
Stanton, Mary Beth
    Thungrat, Kamoltip
      Boothe, Dawn M

        MeSH Terms

        • Animals
        • Anti-Bacterial Agents / pharmacology
        • Bacterial Infections / microbiology
        • Bacterial Infections / veterinary
        • Drug Resistance, Bacterial
        • Female
        • Horse Diseases / microbiology
        • Horses
        • Retrospective Studies
        • Uterine Diseases / microbiology
        • Uterine Diseases / veterinary

        Citations

        This article has been cited 18 times.
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