FREE SHIPPING over $40
OVER 10000 FIVE-STAR REVIEWS
5% OFF ALL SUBSCRIPTIONS
100% HAPPINESS GUARANTEE
Analyze Diet
0
Veterinary medicine and science2026; 12(5); e71146; doi: 10.1002/vms3.71146

Microbiological, Molecular Diagnosis and Antimicrobial Resistance of Bordetella bronchiseptica in the Equine Reproductive Tract in Brazil.

Abstract: The genus Bordetella comprises 16 species of aerobic Gram-negative bacteria, with the most notable being B. pertussis, B. parapertussis and B. bronchiseptica. The latter stands out for its ability to infect various hosts, causing both respiratory and reproductive issues, such as endometritis and infertility in mares. These infections impair reproductive efficiency and facilitate the spread of the pathogen among susceptible animals. Objective: The present study aimed to report the isolation and molecular diagnosis of B. bronchiseptica associated with endometritis and infertility in mares in Brazil, as well as to evaluate the antimicrobial susceptibility profile of the isolates. Methods: For this purpose, uterine lavage was collected from three Mangalarga Marchador mares using an aseptic technique with a transcervical probe and Ringer's lactate solution. The samples were centrifuged, cultured on MacConkey agar, blood agar and Sabouraud agar, and identified by biochemical characteristics. PCR was performed to amplify the flanking region of the flaA gene of B. bronchiseptica, followed by sequencing and analysis. Results: The antibiogram was conducted using the agar diffusion method on Mueller-Hinton agar. Microbial culture identified B. bronchiseptica, confirmed by biochemical and molecular tests. The isolates showed resistance to multiple antibiotics, such as penicillins and cephalosporins. Conclusions: No investigation into transmission routes, prevalence or risk factors in the broader equine population. Conclusions: This study describes, for the first time in Brazil, the detection of B. bronchiseptica causing uterine infection and infertility in mares, expanding knowledge about its pathogenic potential. The results highlight the need to consider this bacterium in the diagnosis of reproductive disorders, even in the absence of respiratory manifestations.
© 2026 The Author(s). Veterinary Medicine and Science published by John Wiley & Sons Ltd.
Get Full Text
Publication Date: 2026-08-21 PubMed ID: 42627632PubMed Central: PMC13496189DOI: 10.1002/vms3.71146Google Scholar: Lookup
The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
LinkedInCopy
  • 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.

Overview

  • This study reports the first identification of Bordetella bronchiseptica causing uterine infection and infertility in mares in Brazil, utilizing microbiological and molecular diagnostic methods.
  • It also evaluates the antimicrobial resistance profile of the isolated bacteria, indicating concerns about treatment effectiveness.

Introduction to Bordetella bronchiseptica and Its Relevance

  • The genus Bordetella consists of 16 species of aerobic Gram-negative bacteria.
  • Notable species include B. pertussis (causes whooping cough in humans), B. parapertussis, and B. bronchiseptica.
  • B. bronchiseptica is unique because it infects multiple hosts and can cause both respiratory diseases and reproductive issues.
  • In horses, it can lead to endometritis (inflammation of the uterine lining) and infertility, which can reduce reproductive efficiency and facilitate pathogen transmission among animals.

Objective of the Study

  • To isolate and molecularly identify B. bronchiseptica linked with uterine infection and infertility in Brazilian mares (specifically Mangalarga Marchador breed).
  • To determine the antimicrobial susceptibility of the bacterial isolates to assess resistance patterns.

Methodology

  • Sample Collection:
    • Uterine lavage samples were collected from three mares using aseptic transcervical techniques with a probe and Ringer’s lactate solution.
  • Microbial Culture:
    • Samples centrifuged and plated on MacConkey agar, blood agar, and Sabouraud agar.
    • Identification based on bacterial growth patterns and biochemical tests.
  • Molecular Diagnosis:
    • PCR was used to amplify the flank region of the flaA gene of B. bronchiseptica.
    • Sequencing and analysis of PCR products confirmed the bacterial species at the molecular level.
  • Antimicrobial Susceptibility Testing:
    • Agar diffusion method performed using Mueller-Hinton agar to determine which antibiotics the isolates were susceptible or resistant to.

Key Findings

  • B. bronchiseptica was successfully isolated and identified from the reproductive tract of mares with endometritis and infertility.
  • Biochemical and molecular evidence corroborated the identification of the bacterium.
  • The bacterial isolates exhibited resistance to multiple antibiotics, notably penicillins and cephalosporins, signaling multidrug resistance concerns.
  • This highlights challenges in treatment and the necessity for antimicrobial resistance monitoring.
  • The study does not explore transmission mechanisms, prevalence, or risk factors in the larger equine population, indicating an area for future research.

Conclusions and Implications

  • This is the first report in Brazil documenting B. bronchiseptica as a cause of uterine infection and infertility in mares.
  • The findings expand the understanding of the pathogenic potential of B. bronchiseptica beyond respiratory disease to reproductive disorders.
  • Veterinary practitioners should consider B. bronchiseptica in differential diagnosis when dealing with equine reproductive disorders, even if respiratory symptoms are absent.
  • The demonstrated antimicrobial resistance underscores the need for proper diagnostic testing and susceptibility profiling to guide effective treatment strategies.
  • Future research is needed to investigate the epidemiology, transmission routes, and risk factors of B. bronchiseptica infections in horses on a broader scale.

Cite This Article

APA
Gallo SSM, Bernardino MLA, Júnior LASDM, Oliveira FCR, Barreto MAP, Folly MM. (2026). Microbiological, Molecular Diagnosis and Antimicrobial Resistance of Bordetella bronchiseptica in the Equine Reproductive Tract in Brazil. Vet Med Sci, 12(5), e71146. https://doi.org/10.1002/vms3.71146

Publication

Veterinary medicine and science
ISSN: 2053-1095
NlmUniqueID: 101678837
Country: England
Language: English
Volume: 12
Issue: 5
Pages: e71146
PII: e71146

Researcher Affiliations

Gallo, Samira Salim Mello
  • Animal Health Laboratory, Universidade Estadual de Norte Fluminense Darcy Ribeiro (UENF), Campos dos Goytacazes, Rio de Janeiro, Brazil.
Bernardino, Maria de Lourdes Amaral
  • Animal Health Laboratory, Universidade Estadual de Norte Fluminense Darcy Ribeiro (UENF), Campos dos Goytacazes, Rio de Janeiro, Brazil.
Júnior, Luiz Antonio Silveira da Motta
  • Animal Health Laboratory, Universidade Estadual de Norte Fluminense Darcy Ribeiro (UENF), Campos dos Goytacazes, Rio de Janeiro, Brazil.
Oliveira, Francisco Carlos Rodrigues de
  • Animal Health Laboratory, Universidade Estadual de Norte Fluminense Darcy Ribeiro (UENF), Campos dos Goytacazes, Rio de Janeiro, Brazil.
Barreto, Marcos Antonio Pessanha
  • Large Animal Clinical and Surgery Laboratory, Universidade Estadual de Norte Fluminense Darcy Ribeiro (UENF), Campos dos Goytacazes, Rio de Janeiro, Brazil.
Folly, Marcio Manhães
  • Animal Health Laboratory, Universidade Estadual de Norte Fluminense Darcy Ribeiro (UENF), Campos dos Goytacazes, Rio de Janeiro, Brazil.

MeSH Terms

  • Animals
  • Brazil / epidemiology
  • Horses
  • Female
  • Horse Diseases / microbiology
  • Horse Diseases / diagnosis
  • Horse Diseases / epidemiology
  • Anti-Bacterial Agents / pharmacology
  • Bordetella bronchiseptica / drug effects
  • Bordetella bronchiseptica / isolation & purification
  • Bordetella bronchiseptica / genetics
  • Bordetella bronchiseptica / physiology
  • Bordetella Infections / veterinary
  • Bordetella Infections / microbiology
  • Bordetella Infections / diagnosis
  • Bordetella Infections / epidemiology
  • Drug Resistance, Bacterial
  • Endometritis / veterinary
  • Endometritis / microbiology
  • Endometritis / diagnosis
  • Endometritis / epidemiology
  • Microbial Sensitivity Tests / veterinary
  • Infertility, Female / veterinary
  • Infertility, Female / microbiology

Conflict of Interest Statement

The authors declare no conflicts of interest.

References

This article includes 34 references
  1. Bauer AW, Kirby WM, Sherris JC, Turck M. Antibiotic Susceptibility Testing by a Standardized Single Disk Method. American Journal of Clinical Pathology 1966 45: 493–496.
    pubmed: 5325707
  2. Beech J. Diseases of the Lung. Veterinary Clinics of North America 1979 1: 149–169.
    pubmed: 228461
  3. Bemis DA, Carmichael LE, Appel MJ. Naturally Occurring respiratory Disease in a Kennel Caused by. Cornell Veterinarian 1977 67: 282–293.
    pubmed: 870289
  4. nnBemis, D. A.n, and Fenwick B.. 2004. “nn.” In Pathogenesis of Bacterial Infections in Animals, edited by Gyles C.L., Prescott J.F., Songer J.G, and Thoen C.O., 259–273, 3rd ed. Wiley‐Blackwell.
  5. Canisso IF, Segabinazzi LGTM, Fedorka CE. Persistent Breeding‐Induced Endometritis in Mares—A Multifaceted Challenge: From Clinical Aspects to Immunopathogenesis and Pathobiology. International Journal of Molecular Sciences 2020 21: 1432.
    doi: 10.3390/ijms21041432pmc: PMC7073041pubmed: 32093296google scholar: lookup
  6. Chamorro BM, Luca KD, Swaminathan G. Mucosal Vaccination With Live Attenuated Protects Against Challenge in Wistar Rats. Vaccines 2023 11: 982.
    doi: 10.3390/vaccines11050982pmc: PMC10224215pubmed: 37243086google scholar: lookup
  7. Christoffersen M, Troedsson M. Inflammation and Fertility in the Mare. Reproduction in Domestic Animals 2017 52: 14–20.
    doi: 10.1111/rda.13013pubmed: 28815848google scholar: lookup
  8. Coutts AJ, Dawson S, Binns S, Hart CA, Gaskell CJ, Gaskell RM. Studies on Natural Transmission of in Cats. Veterinary Microbiology 1996 48: 19–27.
    doi: 10.1016/0378-1135(95)00128-xpubmed: 8701574google scholar: lookup
  9. Diavatopoulos DA, Cummings CA, Schouls LM, Brinig MM, Relman DA, Mooi FR. , the Causative Agent of Whooping Cough, Evolved From a Distinct, Human Associated Lineage of . PLoS Pathogens 2005 1: e45.
    doi: 10.1371/journal.ppat.0010045pmc: PMC1323478pubmed: 16389302google scholar: lookup
  10. Gallagher GL. Isolation of From Horses. Veterinary Records 1965 77: 632–633.
    pubmed: 14331451
  11. Garcia-Cantu MC, Hartmann FA, Brown CM, Darien BJ. and Equine respiratory Infections: A Review of 30 Cases. Equine Veterinary Education 2000 12: 45–50.
  12. Gerlach G, Von Wintzingerode F, Middendorf B, Gross R. Evolutionary Trends in the Genus . Microbes and Infection 2001 3: 61–72.
    doi: 10.1016/s1286-4579(00)01353-8pubmed: 11226855google scholar: lookup
  13. Hasegawa M, Kishino H, Yano T. Dating the Human–Ape Split by a Molecular Clock of Mitochondrial DNA. Journal of Molecular Evolution 1985 22: 160–174.
    pubmed: 3934395
  14. Hernández-Durán M, López-Jácome LE, Colín-Castro CA. Comparison of the MicroScan WalkAway and VITEK 2 Compact Systems for the Identifcation and Susceptibility of Clinical Gram Positive and Gram‐Negative Bacteria. Investigación en Discapacidad 2017 6: 105–114.
  15. Hozbor D, Fouque F, Guiso N. Detection of by the polymerase chain reaction. Research in Microbiology 1999 150: 333–341.
    doi: 10.1016/s0923-2508(99)80059-xpubmed: 10422694google scholar: lookup
  16. Kadlec K, Wiegand I, Kehrenberg C, Schwarz S. Studies on the Mechanisms of β‐Lactam Resistance in. Journal of Antimicrobial Chemotherapy 59: 396–402.
    doi: 10.1093/jac/dkl515pubmed: 17261565google scholar: lookup
  17. Khine S, Rabah L, Palanisamy N, Kailin Lirof K, Bachuwa G. as Sole Organism Responsible for Vertebral Osteomyelitis/Discitis and Vertebral Collapse in a Patient With Intravenous Drug Abuse. BMJ Case Reports 16: e254988.
    doi: 10.1136/bcr-2023-254988pmc: PMC10414099pubmed: 37553172google scholar: lookup
  18. Koehne GW, Herren CE, Gibson RB, Northington WA. An Outbreak of Respiratory Disease in Foals. Veterinary Medicine Small Animal Clinician 76: 507–508.
    pubmed: 6908767
  19. Kumar S, Stecher G, Li M, Knyaz C, Tamura K. MEGA X: Molecular Evolutionary Genetics Analysis Across Computing Platforms. Molecular Biology and Evolution 35: 1547–1549.
    doi: 10.1093/molbev/msy096pmc: PMC5967553pubmed: 29722887google scholar: lookup
  20. Liu IK, Troedsson MH. The Diagnosis and Treatment of Endometritis in the Mare: Yesterday and Today. Theriogenology 70: 415–420.
    doi: 10.1016/j.theriogenology.2008.05.040pubmed: 18513792google scholar: lookup
  21. Mather EC, Owens BAD, Bierschwal CJ, Martin CE. Associated With Infertility in a Mare. Journal of the American Veterinary Medical Association 163: 76–77.
    pubmed: 4711579
  22. Mattoo S, Cherry JD. Molecular Pathogenesis, Epidemiology, and Clinical Manifestations of Respiratory Infections Due to and Other Subspecies. Clinical Microbiology Reviews 18: 326–382.
    doi: 10.1128/CMR.18.2.326-382.2005pmc: PMC1082800pubmed: 15831828google scholar: lookup
  23. Miller WC. Infection in Horses. Veterinary Records 77: 658–659.
  24. Mohan K, Obwolo MJ. From Aborted Equine Foetus. Tropical Animal Health and Production 23: 155–156.
    doi: 10.1007/BF02356994pubmed: 1763436google scholar: lookup
  25. Pathak AK, Boag B, Poss M, Harvill ET, Cattadori IM. Seasonal Breeding Drives the Incidence of a Chronic Bacterial Infection in a Free‐Living Herbivore Population. Epidemiology Infections 139: 1210–1219.
    pubmed: 20943004
  26. Rathbone P, Arango-Sabogal JC, Mestre AM, Scott CJ. Antimicrobial Resistance of Endometrial Bacterial Isolates Collected From UK Thoroughbred Mares Between 2014 and 2020. Veterinary Records 192: e2591.
    doi: 10.1002/vetr.2591pubmed: 36809533google scholar: lookup
  27. Ravaioli V, Raffini E, Tamburini M, Galletti G, Frasnelli M. Infectious Endometritis in Mares: Microbiological Findings in Field Samples. Journal of Equine Veterinary Science 112: 103913.
    doi: 10.1016/j.jevs.2022.103913pubmed: 35196546google scholar: lookup
  28. Register KB, Ivanov YV, Harvill ET, Davison N, Foster G. Novel, Host Restricted Genotypes of Associated With Phocine Respiratory Tract Isolates. Microbiology 161: 580–592.
    doi: 10.1099/mic.0.000035pmc: PMC4811649pubmed: 25627438google scholar: lookup
  29. Saxegaard F, Teige JJ, Fjellheim P. Equine Bronchopneumonia Caused by . A Case Report. Acta Veterinaria Scandinavica 12: 114–115.
    pubmed: 5103407
  30. Schulz BS, Kurz S, Weber K, Balzer HJ, Hartmann K. Detection of respiratory Viruses and in Dogs With Acute Respiratory Tract Infections. Veterinary Journal 2014;201:365–369.
    doi: 10.1016/j.tvjl.2014.04.019pmc: PMC7110455pubmed: 24980809google scholar: lookup
  31. Soumana IH, Linz B, Harvill ET. Environmental Origin of the Genus . Frontiers of Microbiology 2017;8:1–10.
    doi: 10.3389/fmicb.2017.00028pmc: PMC5258731pubmed: 28174558google scholar: lookup
  32. Vaid RK, Shanmugasundaram K, Anand T. Characterization of Isolates of From Horses. Journal of Equine Science 2018;29:25–31.
    doi: 10.1294/jes.29.25pmc: PMC5865067pubmed: 29593446google scholar: lookup
  33. Van Crombrugge E, Vanbeylen E, Van Cleemput J, Van den Broeck W, Laval K, Nauwynck H. Bacterial Toxins From and Predispose the Horse's Respiratory Tract to Equine Herpesvirus Type 1 Infection. Viruses 2022;14:149.
    doi: 10.3390/v14010149pmc: PMC8778808pubmed: 35062352google scholar: lookup
  34. Yacoub AT, Katayama M, Tran J, Zadikany R, Kandula M, Greene J. in the Immunosuppressed Population—A Case Series and Review. Mediterranean Journal of Hematology and Infectious Diseases 2014;6:e2014031.
    doi: 10.4084/MJHID.2014.031pmc: PMC4010603pubmed: 24804004google scholar: lookup

Citations

This article has been cited 0 times.
Subscribe to our newsletter
Join 106,643 horse owners like you who receive our email updates on horse health and nutrition.