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Home / Equine Research Bank / Animals (Basel) / Molecular Detection of Pythium insidiosum in Cutaneous Lesio...
Animals : an open access journal from MDPI2025; 15(19); 2863; doi: 10.3390/ani15192863

Molecular Detection of Pythium insidiosum in Cutaneous Lesions of Horses from Northeastern Brazil.

Abstract: Pythiosis is an underestimated and neglected disease in Brazil, both in horse breeders and in horses. The molecular detection of in horses in the Brazilian Northeast represents a milestone in the epidemiology of equine pythiosis in the country. This study reports novel cases of equine pythiosis, diagnosed by molecular methods, in five states of Northeastern Brazil. Clinical samples were submitted to microbiological culture, DNA extraction, and nested-PCR for molecular detection of . The nested-PCR successfully detected in four out of five equine lesion samples, demonstrating higher sensitivity compared to microbiological culture, which confirmed the pathogen in only one case. These findings reinforce the effectiveness of molecular diagnosis for equine pythiosis compared to conventional methods. This is the first molecular confirmation of in horses from Northeastern Brazil, emphasizing the need for broader surveillance and improved diagnostic approaches in neglected regions.
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Publication Date: 2025-09-30 PubMed ID: 41096457PubMed Central: PMC12524063DOI: 10.3390/ani15192863Google 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.

Overview

  • This study focused on identifying the pathogen Pythium insidiosum in horses with skin lesions from Northeastern Brazil using molecular detection methods.
  • The research highlights the high sensitivity of molecular diagnostics over traditional culture methods in confirming equine pythiosis cases in this region.

Background

  • Pythiosis is a disease caused by the aquatic microorganism Pythium insidiosum, which affects horses and is often overlooked in Brazil.
  • The disease causes cutaneous (skin) lesions that are difficult to diagnose accurately with conventional methods.
  • In Northeastern Brazil, equine pythiosis had not previously been confirmed through molecular diagnostics, leaving a gap in understanding the disease’s epidemiology in this important horse-breeding region.

Objective of the Study

  • To detect Pythium insidiosum in skin lesions of horses from five states in Northeastern Brazil using molecular techniques.
  • To compare the effectiveness of nested-PCR molecular diagnosis with traditional microbiological culture methods for detecting the pathogen.

Methodology

  • Clinical samples were collected from horses exhibiting cutaneous lesions suspected to be due to pythiosis.
  • Samples underwent microbiological culture to attempt to grow Pythium insidiosum using conventional methods.
  • DNA was extracted from the samples for molecular analysis.
  • A nested-polymerase chain reaction (nested-PCR) technique was used to amplify Pythium insidiosum DNA, enhancing detection sensitivity.

Key Findings

  • The nested-PCR successfully detected Pythium insidiosum DNA in four out of five samples, demonstrating high sensitivity.
  • Conventional microbiological culture only confirmed the presence of the pathogen in one sample, indicating lower sensitivity and potential challenges in culturing the organism.
  • The molecular method proved superior in diagnosing equine pythiosis in these clinical cases.
  • This study represents the first molecular confirmation of Pythium insidiosum in horses from Northeastern Brazil.

Significance and Implications

  • The findings showcase the effectiveness of molecular diagnostic tools like nested-PCR for detecting Pythium insidiosum compared to traditional culture techniques.
  • Early and accurate detection of equine pythiosis can improve treatment outcomes and control measures among horse populations in neglected areas.
  • These results emphasize the need for broader epidemiological surveillance of pythiosis in Brazil, especially in regions where the disease is underreported.
  • Improved diagnostic approaches may lead to better awareness and management of this neglected disease among horse breeders and veterinary practitioners in Northeast Brazil.

Cite This Article

APA
Vasconcelos AB, França DA, Prado ACD, Yamauchi DH, Silva ACAD, Barros IO, Valença SRFA, Lucheis SB, Bosco SMG. (2025). Molecular Detection of Pythium insidiosum in Cutaneous Lesions of Horses from Northeastern Brazil. Animals (Basel), 15(19), 2863. https://doi.org/10.3390/ani15192863

Publication

Animals : an open access journal from MDPI
ISSN: 2076-2615
NlmUniqueID: 101635614
Country: Switzerland
Language: English
Volume: 15
Issue: 19
PII: 2863

Researcher Affiliations

Vasconcelos, Artur Bibiano de
  • Department of Animal Production and Preventive Veterinary Medicine, School of Veterinary Medicine and Animal Science, São Paulo State University, Valter Maurício Corrêa, Botucatu 18618-681, Brazil.
França, Danilo Alves de
  • Department of Preventive Veterinary Medicine and Animal Health, School of Veterinary Medicine and Animal Science, University of São Paulo, Orlando Marques de Paiva, São Paulo 05508-270, Brazil.
Prado, Ana Carolina do
  • Department of Animal Production and Preventive Veterinary Medicine, School of Veterinary Medicine and Animal Science, São Paulo State University, Valter Maurício Corrêa, Botucatu 18618-681, Brazil.
Yamauchi, Danielle Hamae
  • Department of Animal Production and Preventive Veterinary Medicine, School of Veterinary Medicine and Animal Science, São Paulo State University, Valter Maurício Corrêa, Botucatu 18618-681, Brazil.
Silva, Andrezza Caroline Aragão da
  • Department of Parasitology and Microbiology, School of Veterinary Medicine, Federal University of Piauí, Avenida Universitária, Teresina 64049-550, Brazil.
Barros, Isabella de Oliveira
  • Department of Microbiology, Centre for Biotechnology, Federal University of Paraíba, Cidade Universitária, João Pessoa 58051-900, Brazil.
Valença, Sandra Regina Fonseca de Araújo
  • Department of Biology, School of Veterinary Medicine, Federal Rural University of Pernambuco, Dom Manoel de Medeiros, Recife 52171-900, Brazil.
Lucheis, Simone Baldini
  • Department of Animal Production and Preventive Veterinary Medicine, School of Veterinary Medicine and Animal Science, São Paulo State University, Valter Maurício Corrêa, Botucatu 18618-681, Brazil.
Bosco, Sandra de Moraes Gimenes
  • Department of Animal Production and Preventive Veterinary Medicine, School of Veterinary Medicine and Animal Science, São Paulo State University, Valter Maurício Corrêa, Botucatu 18618-681, Brazil.

Grant Funding

  • financial Code 001 / Coordination for the Improvement of Higher Education Personnel (CAPES)
  • 2024/23019-3 / São Paulo Research Foundation (FAPESP)

Conflict of Interest Statement

The authors declare no conflicts of interest.

References

This article includes 42 references
  1. Hu L, Huang X, Yee N.H, Meng H, Jiang L, Liang L, Chen X. Pythium insidiosum: An emerging pathogen that is easily misdiagnosed and given treatment as a fungus.. Front. Cell. Infect. Microbiol. 2024;14:1430032.
    doi: 10.3389/fcimb.2024.1430032pmc: PMC11390559pubmed: 39268488google scholar: lookup
  2. Yolanda H, Krajaejun T. Global distribution and clinical features of pythiosis in humans and animals.. J. Fungi. 2022;8:182.
    doi: 10.3390/jof8020182pmc: PMC8879638pubmed: 35205934google scholar: lookup
  3. Sae-Chew P, Rujirawat T, Lohnoo T, Yingyong W, Kumsang Y, Payattikul P, Yurayart N, Yurayart C, Krajaejun T. Generation of protoplasts provides a powerful experimental research tool for biological and pathogenicity studies of Pythium insidiosum.. J. Mycol. Med. 2023;33:101430.
    doi: 10.1016/j.mycmed.2023.101430pubmed: 37678114google scholar: lookup
  4. Permpalung N, Worasilchai N, Chindamporn A. Human pythiosis: Emergence of fungal-like organism.. Mycopathologia. 2020;185:801–812.
    doi: 10.1007/s11046-019-00412-0pubmed: 31845178google scholar: lookup
  5. Nutthapan N, Sutichaiworapong W, Wu Y.H. Human cutaneous pythiosis: A case report.. J. Cutan. Pathol. 2024;51:964–968.
    doi: 10.1111/cup.14719pubmed: 39266281google scholar: lookup
  6. Gaastra W, Lipman L.J.A, De Cock A.W.A.M, Mendoza L, Grooters A.M. Pythium insidiosum: An overview.. Vet. Microbiol. 2010;146:1–16.
    doi: 10.1016/j.vetmic.2010.07.019pubmed: 20800978google scholar: lookup
  7. Pereira D.I.B, Botton S.A, Ianiski L.B, Braga C.Q, Maciel A.F, Melo L.G, Zambrano C.G, Bruhn F.R.P, Santurio J.M. Equidae pythiosis in Brazil and the world: A systematic review of the last 63 years (1960–2023). Braz. J. Microbiol. 2024;55:2969–2981.
    doi: 10.1007/s42770-024-01435-6pmc: PMC11405592pubmed: 38967702google scholar: lookup
  8. Dos Santos C.E.P, Loreto E.S, Zanette R.A, Santurio J.M, Marques L.C. Epidemiology of horse pythiosis in the Pantanal of Mato Grosso: Exploring the host-parasite-vector relationship.. J. Equine Vet. Sci. 2024;132:104976.
    doi: 10.1016/j.jevs.2023.104976pubmed: 38056727google scholar: lookup
  9. Leal A.B.M, Santos R.L, Rodrigues A.M, Menezes R.C, Ogliari D, Castro M. Pitiose equina no pantanal brasileiro: Aspectos clínico-patológicos de casos típicos e atípicos.. Pesq. Vet. Bras. 2001;21:151–156.
    doi: 10.1590/S0100-736X2001000400005google scholar: lookup
  10. Botton S.A, Pereira D.I, Costa M.M, Azevedo M.I, Argenta J.S, Jesus F.P, Alves S.H, Santurio J.M. Identification of Pythium insidiosum by nested PCR in cutaneous lesions of Brazilian horses and rabbits.. Curr. Microbiol. 2011;62:1225–1229.
    doi: 10.1007/s00284-010-9781-4pubmed: 21188592google scholar: lookup
  11. Chagoya-Fuentes J.L, Gaona-López J, Hernández-Carbajal G.R, Torres-Guerrero H, Lammoglia-Villagómez M.A, Huerta-Peña J, Pérez-Brígido C.D, Jácome-Sosa E, Nieto-Rosaliano S.O, Rojas-Ronquillo R. First confirmed case of equine pythiosis in Northern Veracruz, Mexico.. Acta Trop. 2024;254:107195.
    doi: 10.1016/j.actatropica.2024.107195pubmed: 38548212google scholar: lookup
  12. Souto E.P.F, Maia L.A, Miranda Neto E.G, Kommers G.D, Garino Junior F, Riet-Correa F, Galiza G.J.N, Dantas A.F.M. Pythiosis in equidae in Northeastern Brazil: 1985–2020.. J. Equine Vet. Sci. 2021;105:103726.
    doi: 10.1016/j.jevs.2021.103726pubmed: 34607686google scholar: lookup
  13. Offer K.S, Dixon C.E, Sutton D.G.M. Treatment of equine sarcoids: A systematic review.. Equine Vet. J. 2024;56:12–25.
    doi: 10.1111/evj.13935pubmed: 36917551google scholar: lookup
  14. Salem M.A, El-Gameel S.M, Kamel M.S, Elsamman E.M, Ramadan R.M. Innovative diagnostic strategies for equine habronemiasis: Exploring molecular identification, gene expression, and oxidative stress markers.. Parasit. Vectors. 2025;18:325.
    doi: 10.1186/s13071-025-06970-1pmc: PMC12318383pubmed: 40753398google scholar: lookup
  15. Grooters A.M, Gee M.K. Development of a nested polymerase chain reaction assay for the detection and identification of Pythium insidiosum.. J. Vet. Intern. Med. 2002;16:147–152.
    doi: 10.1111/j.1939-1676.2002.tb02346.xpubmed: 11899029google scholar: lookup
  16. Kosrirukvongs P, Chaiprasert A, Canyuk C, Wanachiwanawin W. Comparison of nested PCR and culture identification of Pythium insidiosum in patients with Pythium keratitis.. J. Med. Assoc. Thai. 2016;99:1033–1038.
    pubmed: 29927209
  17. Krajaejun T, Rujirawat T, Lowhnoo T, Yingyong W, Lerksuthirat T, Suriyaphol P, Smittipat N, Juthayothin T, Kittichotirat W, Reamtong O. Pythium insidiosum and human pythiosis, Thailand.. Emerg. Infect. Dis. 2019;25:2295–2305.
  18. Htun ZM, Laikul A, Pathomsakulwong W, Yurayart C, Lohnoo T, Yingyong W, Kumsang Y, Payattikul P, Sae-Chew P, Rujirawat T. An initial survey of 150 horses from Thailand for anti-Pythium insidiosum antibodies.. J. Mycol. Med. 2021;31:101085.
    doi: 10.1016/j.mycmed.2020.101085pubmed: 33259982google scholar: lookup
  19. Tonpitak W, Pathomsakulwong W, Sornklien C, Krajaejun T, Wutthiwithayaphong S. First confirmed case of nasal pythiosis in a horse in Thailand.. JMM Case Rep. 2018;5:e005136.
    doi: 10.1099/jmmcr.0.005136pmc: PMC5857371pubmed: 29568533google scholar: lookup
  20. Gurnani B, Kaur K, Agarwal S, Lalgudi VG, Shekhawat NS, Venugopal A, Tripathy K, Srinivasan B, Iyer G, Gubert J. Pythium insidiosum keratitis: Past, present, and future.. Ophthalmol. Ther. 2022;11:1629–1653.
    doi: 10.1007/s40123-022-00542-7pmc: PMC9255487pubmed: 35788551google scholar: lookup
  21. Vilela R, Grady SC, Vilela PR, Mendoza L. Geographical distribution of human pythiosis in the USA.. Microbiol. Spectr. 2025;13:e0210324.
    doi: 10.1128/spectrum.02103-24pmc: PMC11705800pubmed: 39641546google scholar: lookup
  22. Tartor YH, Hamad MH, Abouzeid NZ, El-Belkemy FA. Equine pythiosis in Egypt: Clinicopathological findings, detection, identification and genotyping of Pythium insidiosum.. Vet. Dermatol. 2020;31:298-e73.
    doi: 10.1111/vde.12845pubmed: 32342602google scholar: lookup
  23. Mendoza L, Alfaro AA. Equine pythiosis in Costa Rica: Report of 39 cases.. Mycopathologia 1986;94:123–129.
    doi: 10.1007/BF00437377pubmed: 3088454google scholar: lookup
  24. Salas Y, Márquez A, Canelón J, Perazzo Y, Colmenárez V, López JA. Equine pythiosis: Report in crossed bred (Criole Venezuelan) horses.. Mycopathologia 2012;174:511–517.
    doi: 10.1007/s11046-012-9562-7pubmed: 22772508google scholar: lookup
  25. Chaffin MK, Schumacher J, McMullan WC. Cutaneous pythiosis in the horse.. Vet. Clin. North. Am. Equine Pract. 1995;11:91–103.
    doi: 10.1016/S0749-0739(17)30334-6pubmed: 7634168google scholar: lookup
  26. Reis JL Jr, de Carvalho EC, Nogueira RH, Lemos LS, Mendoza L. Disseminated pythiosis in three horses.. Vet. Microbiol. 2003;96:289–295.
    doi: 10.1016/j.vetmic.2003.07.005pubmed: 14559176google scholar: lookup
  27. Paz GSD, Camargo GG, Cury JE, Apolonio EVP, Garces HG, Prado ACD, Chechi JL, Oliveira AL, Watanabe MJ, Bagagli E. Outbreak of equine pythiosis in a southeastern region of Brazil: Environmental isolation and phylogeny.. Transbound. Emerg. Dis. 2022;69:1617–1624.
    doi: 10.1111/tbed.14135pubmed: 33991402google scholar: lookup
  28. Schurko AM, Mendoza L, de Cock AWAM, Shahin E, de Hoog GS. Evidência para agrupamentos geográficos: Diferenças genéticas moleculares entre cepas de Pythium insidiosum da Ásia, Austrália e Américas são exploradas.. Mycologia 2003;95:200–208.
    doi: 10.1080/15572536.2004.11833105pubmed: 21156606google scholar: lookup
  29. Krajaejun T, Chongtrakool P, Angkananukul K, Brandhorst TT. Effect of temperature on growth of the pathogenic oomycete Pythium insidiosum.. Southeast Asian J. Trop. Med. Public Health 2010;41:1462–1466.
    pubmed: 21329324
  30. Chitasombat MN, Jongkhajornpong P, Lekhanont K, Krajaejun T. Recent update in diagnosis and treatment of human pythiosis.. PeerJ 2020;8:e8555.
    doi: 10.7717/peerj.8555pmc: PMC7036273pubmed: 32117626google scholar: lookup
  31. Sridapan T, Krajaejun T. Nucleic acid-based detection of Pythium insidiosum: A systematic review.. J. Fungi 2022;9:27.
    doi: 10.3390/jof9010027pmc: PMC9863793pubmed: 36675848google scholar: lookup
  32. Garma-Aviña A, Valli V.E, Lumsden J.H. Equine congenital cutaneous papillomatosis: A report of 5 cases.. Equine Vet. J. 1981;13:59–61.
    doi: 10.1111/j.2042-3306.1981.tb03455.xpubmed: 7238484google scholar: lookup
  33. Thongsri Y, Wonglakorn L, Chaiprasert A, Svobodova L, Hamal P, Pakarasang M, Prariyachatigul C. Evaluation for the Clinical Diagnosis of Pythium insidiosum Using a Single-Tube Nested PCR.. Mycopathologia 2013;176:369–376.
    doi: 10.1007/s11046-013-9695-3pmc: PMC3843749pubmed: 23948967google scholar: lookup
  34. Krajaejun T, Sathapatayavongs B, Pracharktam R, Nitiyanant P, Leelachaikul P, Wanachiwanawin W, Chaiprasert A, Assanasen P, Saipetch M, Mootsikapun P. Clinical and epidemiological analyses of human pythiosis in Thailand.. Clin. Infect. Dis. 2006;43:569–576.
    doi: 10.1086/506353pubmed: 16886148google scholar: lookup
  35. Ud-Naen S, Tansit T, Kanistanon D, Chaiprasert A, Wanachiwanawin W, Srinoulprasert Y. Defective cytokine production from monocytes/macrophages of E-beta thalassemia patients in response to Pythium insidiosum infection.. Immunobiology 2019;224:427–432.
    doi: 10.1016/j.imbio.2019.02.002pubmed: 30765134google scholar: lookup
  36. Weiblen C, Leite F.P, Kommers G.D, Mattos C.L, Barros C.S, Piazer J.V. Seroprevalence of Pythium insidiosum infection in equine in Rio Grande do Sul, Brazil.. Cienc. Rural 2015;46:126–131.
    doi: 10.1590/0103-8478cr20150056google scholar: lookup
  37. França D.A, Langoni H. Prevalent zoonoses in Sao Paulo State, Brazil: The role of bats and molecular diagnosis.. Rev. Inst. Med. Trop. Sao Paulo 2025;67:e17.
    doi: 10.1590/s1678-9946202567017pmc: PMC11883767pubmed: 40053003google scholar: lookup
  38. França D.A, Mioni M.S.R, Fernandes J, Lemos E.R.S, Duré A.Í.L, Silva M.V.F, Langoni H, Megid J. Overview of Q fever in Brazil: An underestimated zoonosis.. Rev. Inst. Med. Trop. Sao Paulo 2023;65:e39.
    doi: 10.1590/s1678-9946202365039pmc: PMC10313319pubmed: 37377322google scholar: lookup
  39. Brazilian Institute of Geography and Statistics (IBGE) Cities and States. [(accessed on 4 September 2025)]; Available online: https://cidades.ibge.gov.br/
  40. National Institute of Meteorology (INMET) Climatological Normals of Brazil (1991–2020) INMET; Brasília, Brazil: 2020. [(accessed on 4 September 2025)]. Available online: https://portal.inmet.gov.br/
  41. Leksuwankun S, Plongla R, Eamrurksiri N, Torvorapanit P, Phongkhun K, Langsiri N, Meejun T, Srisurapanont K, Thanakitcharu J, Lerttiendamrong B. Needs assessment of a pythiosis continuing professional development program.. PLoS Negl. Trop. Dis. 2024;18:e0012004.
    doi: 10.1371/journal.pntd.0012004pmc: PMC10919846pubmed: 38408109google scholar: lookup
  42. Vasconcelos A.B, França D.A, do Prado A.C, Yamauchi D.H, Garces H.G, Oliveira A.L, Carnaúba R.T.M.D.S, Tertuliano Dos Santos C.B, Lucheis S.B, Gimenes Bosco S.M. Development of a multiplex-PCR assay for differentiation of Cryptococcus species using the PRP8 gene region.. Braz. J. Microbiol. 2025.
    doi: 10.1007/s42770-025-01772-0pmc: PMC12660599pubmed: 40864425google scholar: lookup

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