FREE SHIPPING over $40
OVER 9000 FIVE-STAR REVIEWS
5% OFF ALL SUBSCRIPTIONS
100% HAPPINESS GUARANTEE
Analyze Diet
0
Home / Equine Research Bank / Vet Anim Sci / First molecular detection of Francisella tularensis and inve...
Veterinary and animal science2025; 30; 100529; doi: 10.1016/j.vas.2025.100529

First molecular detection of Francisella tularensis and investigation of Coxiella burnetii in horse sera in Iran.

Abstract: Infections caused by and , as zoonotic diseases, pose a serious threat to the health of humans and animals. To date, there is limited information regarding these diseases in horses. This study aimed to evaluate the prevalence of and in the serum of racehorses in Iran (Golestan province). 350 blood samples were collected from racehorses in four regions of Golestan province, and demographic data (sex, age, and sampling location) were recorded. The collected serum samples were examined by PCR to identify the genomes of and . The results showed that 3.4 % (P < 0.05, 95 % CI: 1.97 % - 5.9 %) of the serum samples were positive for genome, while no positive cases for genome were detected. Additionally, a significant relationship was observed between horse age and infection, with the highest prevalence (3.93 %) detected in animals younger than five years (P < 0.05, 95 % CI: 2.21 % - 6.9 %). Moreover, the study revealed a significant difference in prevalence between sexes, with infection rates of 5.84 % in stallions and 1.88 % in mares. Statistical analysis showed no significant difference between the regions studied and the prevalence of . According to our knowledge, this is the first report of tularemia prevalence in horses in Iran. This study indicates that horses can be considered a potential weak reservoir for .
© 2025 The Authors.
Get Full Text
Publication Date: 2025-10-24 PubMed ID: 41245807PubMed Central: PMC12617820DOI: 10.1016/j.vas.2025.100529Google 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 investigates the presence of two zoonotic bacteria, Francisella tularensis and Coxiella burnetii, in racehorses in Golestan province, Iran.
  • It is the first molecular detection of Francisella tularensis in horses in Iran and evaluates the prevalence of Coxiella burnetii, finding only Francisella tularensis in some cases.

Background

  • Francisella tularensis and Coxiella burnetii are bacteria that cause zoonotic diseases, meaning they can be transmitted from animals to humans.
  • These infections pose serious health threats to both humans and animals globally.
  • Limited data existed on the prevalence of these infections specifically in horses, particularly in Iran.

Objectives

  • The research aimed to detect the presence of Francisella tularensis and Coxiella burnetii in the serum of racehorses in Iran’s Golestan province.
  • It also sought to determine demographic factors (such as age, sex, and location) associated with infection rates.

Methodology

  • Researchers collected blood samples from 350 racehorses across four regions in Golestan province.
  • Demographic data recorded included the horse’s age, sex, and the specific sampling location.
  • Serum samples from these blood samples were analyzed using Polymerase Chain Reaction (PCR), a technique that detects specific bacterial DNA to confirm the presence of Francisella tularensis and Coxiella burnetii.

Key Findings

  • 3.4% of the tested horse serum samples contained DNA of Francisella tularensis, indicating infection presence.
  • No Coxiella burnetii DNA was detected in any of the horse serum samples.
  • A statistically significant link was found between the age of horses and infection status:
    • Horses younger than five years showed the highest infection rate at 3.93%.
  • Infection rates differed by sex:
    • Stallions showed a higher prevalence (5.84%) than mares (1.88%).
  • No significant differences in infection rates were found across the four geographical regions sampled within Golestan province.

Implications

  • This is the first study to molecularly confirm tularemia (caused by Francisella tularensis) in horses in Iran.
  • Horses may act as weak reservoirs for Francisella tularensis, meaning they can harbor the bacteria and potentially contribute to its transmission cycle.
  • The absence of Coxiella burnetii DNA in horses in this region suggests that racehorses may not currently be a significant reservoir for Q fever in Golestan province.
  • Understanding the prevalence in horses helps in assessing risks to animal health and zoonotic transmission to humans, especially since racehorses interact closely with humans.

Conclusions and Recommendations

  • The study highlights the importance of surveillance for Francisella tularensis in horses to monitor and mitigate zoonotic disease risks.
  • Further research is recommended to explore the dynamics of tularemia infection in horses and their environment, and to confirm if horses can act as significant reservoirs.
  • Preventive measures could be considered in animal management and public health practices to reduce potential transmission.

Cite This Article

APA
Narouei M, Rahimi H, Kafshdouzan K. (2025). First molecular detection of Francisella tularensis and investigation of Coxiella burnetii in horse sera in Iran. Vet Anim Sci, 30, 100529. https://doi.org/10.1016/j.vas.2025.100529

Publication

Veterinary and animal science
ISSN: 2451-943X
NlmUniqueID: 101694897
Country: Netherlands
Language: English
Volume: 30
Pages: 100529
PII: 100529

Researcher Affiliations

Narouei, Mehdi
  • Department of Pathobiology, Faculty of Veterinary Medicine, Semnan University, Semnan, Iran.
Rahimi, Heidar
  • Department of Pathobiology, Faculty of Veterinary Medicine, Semnan University, Semnan, Iran.
Kafshdouzan, Khatereh
  • Department of Pathobiology, Faculty of Veterinary Medicine, Semnan University, Semnan, Iran.

Conflict of Interest Statement

All authors declare no conflict of interest.

References

This article includes 49 references
  1. Agerholm J, Svejstrup C, Christoffersen A, Agger J. Apparent seroprevalence for coxiella burnetii in the Danish horse population. Dansk Veterinaertidsskrift 2015;98:26–29.
  2. Akimana C, Kwaik YA. Francisella-arthropod vector interaction and its role in patho-adaptation to infect mammals. Frontiers in microbiology 2011;2:34.
    doi: 10.3389/fmicb.2011.00034pmc: PMC3109307pubmed: 21687425google scholar: lookup
  3. Akter R, Legione A, Sansom FM, El-Hage CM, Hartley CA, Gilkerson JR, Devlin JM. Detection of coxiella burnetii and equine herpesvirus 1, but not leptospira spp. Or toxoplasma Gondii, in cases of equine abortion in Australia - a 25 year retrospective study. PloS one 2020;15(5).
    doi: 10.1371/journal.pone.0233100pmc: PMC7250447pubmed: 32453753google scholar: lookup
  4. Ansel S, Benfodil K, Miroud K, Cherif AM, Abdelli A, Kaidi R, Ait-Oudhia Kh. Coxiella Burnetii in Horses of Algeria: Seroprevalence and Associated Risk Factors. World Vet. J. 2021;10(4):602–608.
    doi: 10.54203/scil.2020.wvj72google scholar: lookup
  5. Bäckman S, Näslund J, Forsman M, Thelaus J. Transmission of tularemia from a water source by transstadial maintenance in a mosquito vector. Sci Rep 2015;5:7793.
    doi: 10.1038/srep07793pmc: PMC4302321pubmed: 25609657google scholar: lookup
  6. Balci E, Borlu A, Kilic AU, Demiraslan H, Oksuzkaya A, Doganay M. Tularemia outbreaks in Kayseri, Turkey: An evaluation of the effect of climate change and climate variability on tularemia outbreaks. Journal of Infection and Public Health 2014;7(2):125–132.
    doi: 10.1016/j.jiph.2013.09.002pubmed: 24216516google scholar: lookup
  7. Bamberg WM, Pape WJ, Beebe JL, Nevin-Woods C, Ray W, Maguire H, Nucci J, Massung RF, Gershman K. Outbreak of Q fever associated with a horse-boarding ranch, Colorado, 2005. Vector Borne and Zoonotic Diseases 2007;7(3):394–402.
    doi: 10.1089/vbz.2007.0104pubmed: 17896873google scholar: lookup
  8. Barns SM, Grow CC, Okinaka RT, Keim P, Kuske CR. Detection of diverse new francisella-like bacteria in environmental samples. Applied and Environmental Microbiology 2005;71(9):5494–5500.
    doi: 10.1128/AEM.71.9.5494-5500.2005pmc: PMC1214603pubmed: 16151142google scholar: lookup
  9. Carlsson HE, Lindberg AA, Lindberg G, Hederstedt B, Karlsson KA, Agell BO. Enzyme-linked immunosorbent assay for immunological diagnosis of human tularemia. Journal of Clinical Microbiology 1979;10(5):615–621.
    doi: 10.1128/jcm.10.5.615-621.1979pmc: PMC273233pubmed: 120873google scholar: lookup
  10. Celebi O, Buyuk F, Kirmizigul AH, Gulmez A, Kilic S, Sahin M. The prevalence of tularemia in some farm animals in Kars Region. 2013.
  11. Chaignat V, Djordjevic-Spasic M, Ruettger A, Otto P, Klimpel D, Müller W, Sachse K, Araj G, Diller R, Tomaso H. Performance of seven serological assays for diagnosing tularemia. BMC Infectious Diseases 2014;14:234.
    doi: 10.1186/1471-2334-14-234pmc: PMC4021340pubmed: 24885274google scholar: lookup
  12. Cho HC, Hwang S, Kim EM, Park YJ, Shin SU, Jang DH, Chae JS, Choi KS. Prevalence and molecular characterization of coxiella burnetii in cattle, goats, and horses in the Republic of Korea. Vector Borne and Zoonotic Diseases 2021;21(7):502–508.
    doi: 10.1089/vbz.2020.2764pubmed: 33844947google scholar: lookup
  13. Clark DV, Ismailov A, Seyidova E, Hajiyeva A, Bakhishova S, Hajiyev H, Nuriyev T, Piraliyev S, Bagirov S, Aslanova A, Debes AK, Qasimov M, Hepburn MJ. Seroprevalence of tularemia in rural Azerbaijan. Vector Borne and Zoonotic Diseases 2012;12(7):558–563.
    doi: 10.1089/vbz.2010.0081pubmed: 22452727google scholar: lookup
  14. Dennis DT, Inglesby TV, Henderson DA, Bartlett JG, Ascher MS, Eitzen E, Fine AD, Friedlander AM, Hauer J, Layton M, Lillibridge SR, McDade JE, Osterholm MT, O'Toole T, Parker G, Perl TM, Russell PK, Tonat K. Tularemia as a biological weapon: Medical and public health management. JAMA 2001;285(21):2763–2773.
    doi: 10.1001/jama.285.21.2763pubmed: 11386933google scholar: lookup
  15. Desjardins I, Joulié A, Pradier S, Lecollinet S, Beck C, Vial L, Dufour P, Gasqui P, Legrand L, Edouard S, Sidi-Boumedine K, Rousset E, Jourdain E, Leblond A. Seroprevalence of horses to Coxiella burnetii in an Q fever endemic area. Veterinary Microbiology 2018;215:49–56.
    doi: 10.1016/j.vetmic.2017.11.012pubmed: 29426406google scholar: lookup
  16. Eldin C, Mélenotte C, Mediannikov O, Ghigo E, Million M, Edouard S, Mege JL, Maurin M, Raoult D. From Q fever to coxiella burnetii infection: A paradigm change. Clinical Microbiology Reviews 2017;30(1):115–190.
    doi: 10.1128/CMR.00045-16pmc: PMC5217791pubmed: 27856520google scholar: lookup
  17. Esmaeili S, Ghasemi A, Naserifar R, Jalilian A, Molaeipoor L, Maurin M, Mostafavi E. Epidemiological survey of tularemia in Ilam Province, west of Iran. BMC Infectious Diseases 2019;19(1):502.
    doi: 10.1186/s12879-019-4121-1pmc: PMC6556031pubmed: 31174488google scholar: lookup
  18. Esmaeili S, Rohani M, Ghasemi A, Gouya MM, Khayatzadeh S, Mahmoudi A, Ahangari Cohan H, Johansson A, Maurin M, Mostafavi E. Francisella tularensis human infections in a village of northwest Iran. BMC Infectious Diseases 2021;21(1):310.
    doi: 10.1186/s12879-021-06004-ypmc: PMC8010941pubmed: 33789598google scholar: lookup
  19. Esmaeili S, Latifian M, Mahmoudi A, Ghasemi A, Mohammadi A, Mordadi A, Ziapour SP, Naddaf SR, Mostafavi E. Molecular investigation of coxiella burnetii and francisella tularensis infection in ticks in northern, western, and northwestern Iran. PloS one 2023;18(8).
    doi: 10.1371/journal.pone.0289567pmc: PMC10434890pubmed: 37590254google scholar: lookup
  20. Faber M, Heuner K, Jacob D, Grunow R. Tularemia in Germany-A re-emerging zoonosis. Frontiers in Cellular and Infection Microbiology 2018;8:40.
    doi: 10.3389/fcimb.2018.00040pmc: PMC5821074pubmed: 29503812google scholar: lookup
  21. Fooladfar Z, Moradi F. Francisella and tularemia in western Asia, Iran: A systematic review. New Microbes and New Infections 2023;52.
    doi: 10.1016/j.nmni.2023.101092pmc: PMC9932182pubmed: 36816490google scholar: lookup
  22. Fulop M, Leslie D, Titball R. A rapid, highly sensitive method for the detection of francisella tularensis in clinical samples using the polymerase chain reaction. The American Journal of Tropical Medicine and Hygiene 1996;54(4):364–366.
    doi: 10.4269/ajtmh.1996.54.364pubmed: 8615448google scholar: lookup
  23. Global Horse Statistics 2019. https://www.researchgate.net/publication/331234705_Global_Horse_statistics_internal_02_2019 Global horse statistics internal 02/2019. ResearchGate.
  24. Hemati M, Khalili M, Rohani M, Sadeghi B, Esmaeili S, Ghasemi A, Mahmoudi A, Gyuranecz M, Mostafavi E. A serological and molecular study on francisella tularensis in rodents from Hamadan province, Western Iran. Comp immuno, Microbiol Infect Dis 2020;68.
    doi: 10.1016/j.cimid.2019.101379pubmed: 31733511google scholar: lookup
  25. Hestvik G, Warns-Petit E, Smith LA, Fox NJ, Uhlhorn H, Artois M, Hannant D, Hutchings MR, Mattsson R, Yon L, Gavier-Widen D. The status of tularemia in Europe in a one-health context: A review. Epidemiol Infect 2015;143:2137–2160.
    doi: 10.1017/S0950268814002398pmc: PMC9506979pubmed: 25266682google scholar: lookup
  26. Jaferi M, Mozaffari A, Jajarmi M, Imani M, Khalili M. Serologic and molecular survey of horses to Coxiella burnetii in East of Iran a highly endemic area. Comparat Immuno, Microbiol Infect Dis 2021;76.
    doi: 10.1016/j.cimid.2021.101647pubmed: 33894478google scholar: lookup
  27. Jonckers Nieboer LFW, Fischer EAJ, MAH Braks. Available evidence for mosquito-borne Francisella tularensis transmission is inconclusive. Frontiers in Tropical Diseases 2023;4.
    doi: 10.3389/fitd.2023.1230903google scholar: lookup
  28. Khademi P, Ownagh A, Ataei B, Kazemnia A, Eydi J, Khalili M, M M, Mardani K. Molecular detection of coxiella burnetii in horse sera in Iran. Comp Immuno, Microbiol Infect Dis 2020;72.
    doi: 10.1016/j.cimid.2020.101521pmc: PMC7377784pubmed: 32721772google scholar: lookup
  29. Khademi P, Ownagh G, Ataei B, Kazemnia A, Enferadi A, Khalili M, Mardani K. Prevalence of C. burnetii DNA in sheep and goats milk in the northwest of Iran. International Journal of Food Microbiology 2020.
    doi: 10.1016/j.ijfoodmicro.2020.108716pubmed: 32521375google scholar: lookup
  30. Khademi P, Ownagh A, Mardani K, Khalili M. Prevalence of coxiella burnetii in milk collected from buffalo (water buffalo) and cattle dairy farms in Northwest of Iran. Comparative Immunology, Microbiology and Infectious Diseases 2019.
    doi: 10.1016/j.cimid.2019.101368pubmed: 31627037google scholar: lookup
  31. Marenzoni ML, Stefanetti V, Papa P, Casagrande Proietti P, Bietta A, Coletti M, Passamonti F, Henning K. Is the horse a reservoir or an indicator of Coxiella burnetii infection? Systematic review and biomolecular investigation. Veterinary Microbiology 2013;167(3–4):662–669.
    doi: 10.1016/j.vetmic.2013.09.027pubmed: 24144862google scholar: lookup
  32. Mares-Guia MA, Rozental T, Guterres A, Gomes R, Almeida DN, Moreira NS, Barreira JD, Favacho AR, Santana AL, Lemos ER. Molecular identification of the agent of Q fever - coxiella burnetii - in domestic animals in State of Rio de Janeiro, Brazil. Revista da Sociedade Brasileira de Medicina Tropical 2014;47(2):231–234.
    doi: 10.1590/0037-8682-0076-2013pubmed: 24861300google scholar: lookup
  33. Melenotte C, Million M, Raoult D. New insights in Coxiella burnetii infection: Diagnosis and therapeutic update. Expert Review of Anti-infective Therapy 2020;18:75–86.
    doi: 10.1080/14787210pubmed: 31782315google scholar: lookup
  34. Maurin M, Raoult D. Q fever. Clinical Microbiology Reviews 1999;12(4):518–553.
    doi: 10.1128/CMR.12.4.518pmc: PMC88923pubmed: 10515901google scholar: lookup
  35. Motamedi S, Rashidian E, Jaydari A, Rahimi H, Khademi P. Epidemiological and molecular survey of coxiella burnetii from the serum of patients suspected of brucellosis in west of Iran. Infection, Genetics and Evolution 2025;130.
    doi: 10.1016/j.meegid.2025.105743pubmed: 40132740google scholar: lookup
  36. Mostafavi E, Ghasemi A, Rohani M, Molaeipoor L, Esmaeili S, Mohammadi Z, Mahmoudi A, Aliabadian M, Johansson A. Molecular survey of tularemia and plague in small mammals from Iran. Frontiers in Cellular and Infection Microbiology 2018;8:215.
    doi: 10.3389/fcimb.2018.00215pmc: PMC6048195pubmed: 30042927google scholar: lookup
  37. Mostafavi E, Shahraki AH, Japoni-Nejad A, Esmaeili S, Darvish J, Sedaghat MM, Mohammadi A, Mohammadi Z, Mahmoudi A, Pourhossein B, Ghasemi A, Gyuranecz M, Carniel E. A field study of plague and tularemia in rodents, western Iran. Vector borne and Zoonotic Diseases 2017;17(4):247–253.
    doi: 10.1089/vbz.2016.2053pubmed: 28165869google scholar: lookup
  38. Origgi FC, König B, Lindholm AK, Mayor D, Pilo P. Tularemia among free-ranging mice without infection of exposed humans, Switzerland, 2012. Emerging Infectious Diseases 2015;21(1):133–135.
    doi: 10.3201/eid2101.140906pmc: PMC4285241pubmed: 25531919google scholar: lookup
  39. Ownagh A, Rajabi SA, Enferadi A, Hadian M. Molecular detection and phylogenetic analysis of Borrelia Spp. In blood samples of cats and dogs by the nested-PCR method in West Azerbaijan Province. Iran Brazilian Journal of Microbiology 2024;55(3):2915–2922.
    doi: 10.1007/s42770-024-01401-2pmc: PMC11405608pubmed: 38819772google scholar: lookup
  40. Parhizgari N, Gouya MM, Mostafavi E. Emerging and re-emerging infectious diseases in Iran. Iranian Journal of Microbiology 2017;9(3):122–142.
    pmc: PMC5719507pubmed: 29225752
  41. Parisi A, Fraccalvieri R, Cafiero M, Miccolupo A, Padalino I, Montagna C, Sottili R. Diagnosis of Coxiella burnetii-related abortion in Italian domestic ruminants using single-tube nested PCR. Veterinary Microbiology 2006;118(1–2):101–106.
    doi: 10.1016/j.vetmic.2006.06.023pubmed: 16891064google scholar: lookup
  42. Petersen JM, Mead PS, Schriefer ME. Francisella tularensis: An arthropod-borne pathogen. Veterinary Research 2009;40(2):7.
    doi: 10.1051/vetres:2008045pmc: PMC2695023pubmed: 18950590google scholar: lookup
  43. Rahravani M, Moravedji M, Mostafavi E, Baseri N, Seyfi H, Mohammadi M, Ziaei AH, Mozoun MM, Latifian M, Esmaeili S. Molecular detection of Francisella tularensis in small ruminants and their ticks in western Iran. Comparative Immunology, Microbiology and Infectious Diseases 2022;83.
    doi: 10.1016/j.cimid.2022.101779pubmed: 35228156google scholar: lookup
  44. Rossow H, Forbes KM, Tarkka E, Kinnunen PM, Hemmilä H, Huitu O, Nikkari S, Henttonen H, Kipar A, Vapalahti O. Experimental infection of voles with Francisella tularensis indicates their amplification role in tularemia outbreaks. PloS one 2014;9(10).
    doi: 10.1371/journal.pone.0108864pmc: PMC4182746pubmed: 25271640google scholar: lookup
  45. Tukmechi A, Ownagh A, Enferadi A, Khademi P. First molecular detection of francisella tularensis in turtle (Testudo graeca) and ticks (Hyalomma aegyptium) in Northwest of Iran. International journal for parasitology. Parasites and Wildlife 2023;23.
    doi: 10.1016/j.ijppaw.2023.11.005pmc: PMC10772711pubmed: 38192304google scholar: lookup
  46. Willi Y, Buskirk JV, Hoffmann AA. Limits to the adaptive potential of small populations. Annual Review of Ecology, Evolution, and Systematics 2006;37:433–458.
    doi: 10.1146/annurev.ecolsys.37.091305.110145google scholar: lookup
  47. Yeni DK, Akça D. The prevalence of francisella tularensis in horse herds in Turkey. Veterinary Journal of Mehmet Akif Ersoy University 2022;7(2):116–119.
    doi: 10.24880/maeuvfd.1095230google scholar: lookup
  48. Yeni DK, Büyük F, Ashraf A, Shah MSUD. Tularemia: A re-emerging tick-borne infectious disease. Folia Microbiologica 2021;66(1):1–14.
    doi: 10.1007/s12223-020-00827-zpmc: PMC7521936pubmed: 32989563google scholar: lookup
  49. Zargar A, Maurin M, Mostafavi E. Tularemia, a re-emerging infectious disease in Iran and neighboring countries. Epidemiology and Health 2015;22(37).
    doi: 10.4178/epih/e2015011pmc: PMC4430760pubmed: 25773439google scholar: lookup

Citations

This article has been cited 0 times.
Subscribe to our newsletter
Join 99,000 horse owners like you who receive our email updates on horse health and nutrition.