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Pathogens (Basel, Switzerland)2025; 14(4); doi: 10.3390/pathogens14040357

Characteristics of the Mare-Uterine-Culture-Based Bacterial Composition Using Practical Clinical Evaluation Methods.

Abstract: Uterine health is paramount to fertility in broodmares and for the success of a breeding project, and the Lusitano breed is no exception. This study aimed to characterize the mare uterine microbiota using practical clinical evaluation methods. Mares were examined by transrectal palpation and ultrasonography, followed by the collection of samples by one of three different techniques: uterine lavage, biopsy, or swab. The results of cytology, histology, microbiology, and antimicrobial susceptibility testing were recorded, and statistical analyses were performed. Inflammation was present in 42.2% of the mares and positive culture in 65.4%. Escherichia coli and Streptococcus spp. were the most isolated microorganisms. The most efficient antimicrobials were gentamicin, trimethoprim-sulfamethoxazole, and enrofloxacin and resistance was detected mainly for doxycycline, penicillin, and ceftiofur. The phase of the cycle was significantly associated with the presence of inflammation (p = 0.0308). The isolation of Gram-positive or Gram-negative bacteria correlated to the microbiological isolation by primoculture/enrichment processes (p = 0.0183). This was a routine standard breeding evaluation of broodmares in the management of a stud farm, hence displaying the characteristics of a field study. The antimicrobial resistance findings reinforce the importance of performing microbiology and susceptibility tests, even under field conditions, to maximize targeted antimicrobial therapy efficiency and minimize the worldwide problem of antimicrobial resistance, promoting antimicrobial stewardship.
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Publication Date: 2025-04-07 PubMed ID: 40333165PubMed Central: PMC12030173DOI: 10.3390/pathogens14040357Google Scholar: Lookup
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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 study outlines an investigation into the bacterial make-up of the mare uterus through clinical evaluation methods, with the aim of informing breeding programs and fertility treatments. The research also explores the rising issue of antibiotic resistance and its implications in the treatment of broodmares’ uterine health, highlighting the significance of conducting microbiology and susceptibility tests.

Methodology

  • The study carried out physical evaluations on mares using transrectal palpation and ultrasonography, two common methods for investigating reproductive health in horses.
  • Sampling of the mares’ uterus was then done using either uterine lavage, biopsy or swabbing techniques.
  • The research used a combination of cytology, histology, and microbiology evaluations, and conducted antimicrobial susceptibility tests on the samples collected.
  • The gathered data was then statistically analyzed.

Findings

  • Among the broodmares examined, 42.2% had inflammation present while 65.4% had a positive culture, indicating the presence of bacteria.
  • The bacteria most frequently isolated were Streptococcus and Escherichia coli. These bacteria are known to affect reproductive health in mares.
  • Antimicrobials such as gentamicin, trimethoprim-sulfamethoxazole, and enrofloxacin were found to be the most effective. Meanwhile, resistance was primarily detected for doxycycline, penicillin, and ceftiofur.

Cycle Phase and Bacteria Type

  • One significant outcome was a noted association between the phase of the mares’ cycle and the presence of inflammation, affirming that the hormonal and physical changes during the cycle influence uterine health.
  • An additional correlation was found between the type of bacteria -Gram-positive or Gram-negative – and the bacteria isolated by primoculture/enrichment processes.

Conclusion

  • The study emphasized the necessity of field tests for bacteria and susceptibility, to improve targeted antibiotic treatments, thereby reducing the risk of antimicrobial resistance.
  • The practices involved in the research form a standard routine in managing stud farm broodmare health, with these results offering valuable information for the breeding industry.

Cite This Article

APA
Carvalho IB, Branco S, Laranjo M, Queiroga MC, Bettencourt E. (2025). Characteristics of the Mare-Uterine-Culture-Based Bacterial Composition Using Practical Clinical Evaluation Methods. Pathogens, 14(4). https://doi.org/10.3390/pathogens14040357

Publication

Pathogens (Basel, Switzerland)
ISSN: 2076-0817
NlmUniqueID: 101596317
Country: Switzerland
Language: English
Volume: 14
Issue: 4

Researcher Affiliations

Carvalho, Inês B
  • MED-Mediterranean Institute for Agriculture, Environment and Development & CHANGE-Global Change and Sustainability Institute, Institute for Advanced Studies and Research, Universidade de Évora, Pólo da Mitra, 7000 Évora, Portugal.
  • Unidade Clínica de Alter, Hospital Veterinário da Universidade de Évora, Universidade de Évora, 7440 Alter do Chão, Portugal.
Branco, Sandra
  • MED-Mediterranean Institute for Agriculture, Environment and Development & CHANGE-Global Change and Sustainability Institute, Institute for Advanced Studies and Research, Universidade de Évora, Pólo da Mitra, 7000 Évora, Portugal.
  • Departamento de Medicina Veterinária, Escola de Ciências e Tecnologia, Universidade de Évora, 7000 Évora, Portugal.
Laranjo, Marta
  • MED-Mediterranean Institute for Agriculture, Environment and Development & CHANGE-Global Change and Sustainability Institute, Institute for Advanced Studies and Research, Universidade de Évora, Pólo da Mitra, 7000 Évora, Portugal.
  • Departamento de Medicina Veterinária, Escola de Ciências e Tecnologia, Universidade de Évora, 7000 Évora, Portugal.
Queiroga, Maria Cristina
  • MED-Mediterranean Institute for Agriculture, Environment and Development & CHANGE-Global Change and Sustainability Institute, Institute for Advanced Studies and Research, Universidade de Évora, Pólo da Mitra, 7000 Évora, Portugal.
  • Departamento de Medicina Veterinária, Escola de Ciências e Tecnologia, Universidade de Évora, 7000 Évora, Portugal.
Bettencourt, Elisa
  • MED-Mediterranean Institute for Agriculture, Environment and Development & CHANGE-Global Change and Sustainability Institute, Institute for Advanced Studies and Research, Universidade de Évora, Pólo da Mitra, 7000 Évora, Portugal.
  • Unidade Clínica de Alter, Hospital Veterinário da Universidade de Évora, Universidade de Évora, 7440 Alter do Chão, Portugal.
  • Departamento de Medicina Veterinária, Escola de Ciências e Tecnologia, Universidade de Évora, 7000 Évora, Portugal.

MeSH Terms

  • Female
  • Animals
  • Horses / microbiology
  • Anti-Bacterial Agents / pharmacology
  • Uterus / microbiology
  • Uterus / pathology
  • Microbial Sensitivity Tests
  • Bacteria / isolation & purification
  • Bacteria / drug effects
  • Bacteria / classification
  • Microbiota
  • Drug Resistance, Bacterial

Grant Funding

  • UIDB/05183 / Fundação para a Ciência e Tecnologia

Conflict of Interest Statement

The authors declare no conflicts of interest.

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