{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,30]],"date-time":"2026-07-30T18:23:30Z","timestamp":1785435810430,"version":"3.56.0"},"reference-count":41,"publisher":"MDPI AG","issue":"12","license":[{"start":{"date-parts":[[2026,6,15]],"date-time":"2026-06-15T00:00:00Z","timestamp":1781481600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100013805","name":"Special Research Fund of Shanxi Agricultural University for High-level Talents","doi-asserted-by":"publisher","award":["2021XG001"],"award-info":[{"award-number":["2021XG001"]}],"id":[{"id":"10.13039\/501100013805","id-type":"DOI","asserted-by":"publisher"}]},{"award":["2021XG001"],"award-info":[{"award-number":["2021XG001"]}],"id":[{"id":"https:\/\/ror.org\/05e9f5362","id-type":"ROR","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Animals"],"abstract":"<jats:p>Giardia duodenalis (synonyms G. lamblia and G. intestinalis) and Blastocystis sp. are prevalent zoonotic intestinal protozoans with significant public health and economic importance. Both parasites infect various hosts, including humans and most livestock. G. duodenalis can cause infections ranging from asymptomatic carriage to clinical manifestations such as acute diarrheal disease, growth stunting and malabsorption, whereas Blastocystsi sp. infection is often asymptomatic and its pathogenicity remains debated. Following the rapid expansion of modern equine industries (horse racing, equestrian sports, production, and tourism), concern about the spread of parasitic diseases caused by human\u2013horse contact has gradually increased. In this study, 631 horse fecal specimens were collected from three geographical localities in Shanxi Province, North China. The prevalence and genetic characteristics of the two parasites were determined by amplification of multiple genetic loci (tpi, triosephosphate isomerase; gdh, glutamate dehydrogenase; bg, beta-giardin) for G. duodenalis and the small subunit ribosomal RNA (SSU rRNA) gene for Blastocystis sp. Overall, the prevalence of G. duodenalis and Blastocystis sp. in horses in Shanxi Province was 7.9% and 0.8%, respectively. Sequence analysis identified three assemblages (A, B, and E) of G. duodenalis and two subtypes (ST1 and ST5) of Blastocystis sp. in horses; assemblage B and subtype ST1 were detected more frequently than the other types (subtypes) in this data set. This study is the first to report G. duodenalis and Blastocystis sp. infections in horses in Shanxi Province, and these findings provide baseline molecular epidemiological data for horses in Shanxi Province and support continued hygiene management to reduce potential zoonotic transmission.<\/jats:p>","DOI":"10.3390\/ani16121845","type":"journal-article","created":{"date-parts":[[2026,6,15]],"date-time":"2026-06-15T15:00:48Z","timestamp":1781535648000},"page":"1845","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Prevalence and Genetic Characterization of Giardia duodenalis and Blastocystis sp. in Horses in Shanxi Province, North China"],"prefix":"10.3390","volume":"16","author":[{"ORCID":"https:\/\/orcid.org\/0009-0006-7739-656X","authenticated-orcid":false,"given":"Xun-Zhi","family":"Liu","sequence":"first","affiliation":[{"name":"Shanxi Key Laboratory of Animal Disease Research, Prevention and Control, College of Veterinary Medicine, Shanxi Agricultural University, Jinzhong 030801, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Nan","family":"Su","sequence":"additional","affiliation":[{"name":"Shanxi Key Laboratory of Animal Disease Research, Prevention and Control, College of Veterinary Medicine, Shanxi Agricultural University, Jinzhong 030801, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Wen","family":"Li","sequence":"additional","affiliation":[{"name":"Shanxi Key Laboratory of Animal Disease Research, Prevention and Control, College of Veterinary Medicine, Shanxi Agricultural University, Jinzhong 030801, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Dong-Yang","family":"Wang","sequence":"additional","affiliation":[{"name":"Shanxi Key Laboratory of Animal Disease Research, Prevention and Control, College of Veterinary Medicine, Shanxi Agricultural University, Jinzhong 030801, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0007-5055-2371","authenticated-orcid":false,"given":"Ze-Dong","family":"Zhang","sequence":"additional","affiliation":[{"name":"Shanxi Key Laboratory of Animal Disease Research, Prevention and Control, College of Veterinary Medicine, Shanxi Agricultural University, Jinzhong 030801, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2530-4628","authenticated-orcid":false,"given":"Xing-Quan","family":"Zhu","sequence":"additional","affiliation":[{"name":"Shanxi Key Laboratory of Animal Disease Research, Prevention and Control, College of Veterinary Medicine, Shanxi Agricultural University, Jinzhong 030801, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Wen-Wei","family":"Gao","sequence":"additional","affiliation":[{"name":"Shanxi Key Laboratory of Animal Disease Research, Prevention and Control, College of Veterinary Medicine, Shanxi Agricultural University, Jinzhong 030801, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,6,15]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/B978-0-12-407706-5.00001-0","article-title":"Recent developments in Blastocystis research","volume":"82","author":"Clark","year":"2013","journal-title":"Adv. Parasitol."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"1099","DOI":"10.1016\/j.ijpara.2021.08.007","article-title":"Taxonomy and molecular epidemiology of Cryptosporidium and Giardia\u2014A 50 year perspective (1971\u20132021)","volume":"51","author":"Ryan","year":"2021","journal-title":"Int. J. Parasitol."},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Hatam-Nahavandi, K., Ahmadpour, E., Badri, M., Eslahi, A.V., Anvari, D., Carmena, D., and Xiao, L. (2025). Global prevalence of Giardia infection in nonhuman mammalian hosts: A systematic review and meta-analysis of five million animals. PLoS Negl. Trop. Dis., 19.","DOI":"10.1371\/journal.pntd.0013021"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"417","DOI":"10.1097\/QCO.0000000000000877","article-title":"Giardia and growth impairment in children in high-prevalence settings: Consequence or co-incidence?","volume":"35","author":"Dougherty","year":"2022","journal-title":"Curr. Opin. Infect. Dis."},{"key":"ref_5","doi-asserted-by":"crossref","unstructured":"Hatam-Nahavandi, K., Ahmadpour, E., Rezaeian, M., Mohammad Rahimi, H., Meamar, A., Badri, M., Vafae Eslahi, A., Rahdar, H.A., Sepahi, S., and Mirjalali, H. (2024). Occurrence and assemblage distribution of Giardia duodenalis in symptomatic and asymptomatic patients in southeastern Iran (2019\u20132022). Gut Pathog., 16.","DOI":"10.1186\/s13099-024-00666-0"},{"key":"ref_6","doi-asserted-by":"crossref","unstructured":"Ahlawat, G.M., and Singh, P.K. (2023). Methods of determining irritable bowel syndrome and efficiency of probiotics in treatment: A review. Curr. Ther. Res. Clin. Exp., 99.","DOI":"10.1016\/j.curtheres.2023.100721"},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"Darwish, B., Aboualchamat, G., and Al Nahhas, S. (2025). Blastocystis ST1: Protein profile and specific serum immunoglobulin in irritable bowel syndrome (IBS) patients. Acta Parasitol., 70.","DOI":"10.1007\/s11686-024-00946-4"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"260","DOI":"10.1016\/j.rvsc.2020.09.031","article-title":"Blastocystis in domesticated and wild mammals and birds","volume":"135","author":"Hublin","year":"2021","journal-title":"Res. Vet. Sci."},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Elmahallawy, E.K., K\u00f6ster, P.C., Dashti, A., Alghamdi, S.Q., Saleh, A., Gareh, A., Alrashdi, B.M., Hern\u00e1ndez-Castro, C., Bailo, B., and Lokman, M.S. (2023). Molecular detection and characterization of Cryptosporidium spp., Giardia duodenalis, and Enterocytozoon bieneusi infections in dromedary camels (Camelus dromedaries) in Egypt. Front. Vet. Sci., 10.","DOI":"10.3389\/fvets.2023.1139388"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"335","DOI":"10.1016\/j.meegid.2017.12.001","article-title":"Host specificity in the Giardia duodenalis species complex","volume":"66","author":"Lalle","year":"2018","journal-title":"Infect. Genet. Evol."},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Mizani, A., Taherkhani, P., Kia Lashaki, E., Hosseini, S.A., Basirpour, B., and Dodangeh, S. (2025). The global prevalence of Giardia infection in horses: A systematic review and meta-analysis. J. Equine Vet. Sci., 150.","DOI":"10.1016\/j.jevs.2025.105596"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"1101","DOI":"10.1007\/s00436-020-06612-8","article-title":"Zoonotic potential of Enterocytozoon bieneusi and Giardia duodenalis in horses and donkeys in northern China","volume":"119","author":"Li","year":"2020","journal-title":"Parasitol. Res."},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Hatam-Nahavandi, K., Mohammad Rahimi, H., Rezaeian, M., Ahmadpour, E., Badri, M., and Mirjalali, H. (2025). Detection and molecular characterization of Blastocystis sp., Enterocytozoon bieneusi and Giardia duodenalis in asymptomatic animals in southeastern Iran. Sci. Rep., 15.","DOI":"10.1038\/s41598-025-90608-w"},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Shams, M., Shamsi, L., Yousefi, A., Sadrebazzaz, A., Asghari, A., Mohammadi-Ghalehbin, B., Shahabi, S., and Hatam, G. (2022). Current global status, subtype distribution and zoonotic significance of Blastocystis in dogs and cats: A systematic review and meta-analysis. Parasit. Vectors, 15.","DOI":"10.1186\/s13071-022-05351-2"},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Naguib, D., Gantois, N., Desramaut, J., Dominguez, R.G., Arafat, N., Atwa, S.M., Even, G., Devos, D.P., Certad, G., and Chab\u00e9, M. (2024). Large-scale molecular epidemiological survey of Blastocystis sp. among herbivores in Egypt and assessment of potential zoonotic risk. Microorganisms, 12.","DOI":"10.3390\/microorganisms12071286"},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Asghari, A., Yousefi, A., Mohammadi, M.R., Badali, R., Shamsi, L., K\u00f6seo\u011flu, A.E., Abbaszadeh, A., Shams, M., and Mohammadi-Ghalehbin, B. (2024). Comparative molecular epidemiology, subtype distribution, and zoonotic potential of Blastocystis sp. in Equus animals (horses, donkeys, and mules) in northwestern Iran. Comp. Immunol. Microbiol. Infect. Dis., 106.","DOI":"10.1016\/j.cimid.2024.102124"},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Zhang, S., Zhang, T.H., Jia, T., Su, N., Xie, S.C., Li, S., Tian, X., Zhu, X.Q., Liu, Q., and Gao, W.W. (2024). Prevalence and genotype\/subtype distribution of Enterocytozoon bieneusi and Blastocystis in donkeys in Shanxi Province, north China. Parasitol. Res., 123.","DOI":"10.1007\/s00436-024-08128-x"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"483","DOI":"10.1007\/s00436-019-06594-2","article-title":"Prevalence and multilocus analysis of Giardia duodenalis in racehorses in China","volume":"119","author":"Qi","year":"2020","journal-title":"Parasitol. Res."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"169","DOI":"10.1016\/j.vetpar.2015.02.030","article-title":"Molecular identification of Cryptosporidium spp. and Giardia duodenalis in grazing horses from Xinjiang, China","volume":"209","author":"Qi","year":"2015","journal-title":"Vet. Parasitol."},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Zhang, Q., Zhang, Z., Ai, S., Wang, X., Zhang, R., and Duan, Z.C.s. (2019). Enterocytozoon bieneusi, and Giardia duodenalis from animal sources in the Qinghai-Tibetan Plateau Area (QTPA) in China. Comp. Immunol. Microbiol. Infect. Dis., 67.","DOI":"10.1016\/j.cimid.2019.101346"},{"key":"ref_21","unstructured":"Thrusfield, M. (2018). Veterinary Epidemiology, Wiley Blackwell. [4th ed.]."},{"key":"ref_22","doi-asserted-by":"crossref","unstructured":"Xiao, H.D., Su, N., Zhang, Z.D., Dai, L.L., Luo, J.L., Zhu, X.Q., Xie, S.C., and Gao, W.W. (2024). Prevalence and genetic characterization of Giardia duodenalis and Blastocystis spp. in black goats in Shanxi province, North China: From a public health perspective. Animals, 14.","DOI":"10.3390\/ani14121808"},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Abarca, N., Sant\u00edn, M., Ortega, S., Maloney, J.G., George, N.S., Molokin, A., Cardona, G.A., Dashti, A., K\u00f6ster, P.C., and Bailo, B. (2021). Molecular detection and characterization of Blastocystis sp. and Enterocytozoon bieneusi in cattle in northern Spain. Vet. Sci., 8.","DOI":"10.3390\/vetsci8090191"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"103","DOI":"10.1016\/S0304-4017(00)00356-3","article-title":"Prevalence of Cryptosporidium, Giardia and Eimeria infections in post-weaned and adult cattle on three Maryland farms","volume":"93","author":"Fayer","year":"2000","journal-title":"Vet. Parasitol."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"524","DOI":"10.1128\/JCM.02520-15","article-title":"Blastocystis in health and disease: Are we moving from a clinical to a public health perspective?","volume":"54","author":"Andersen","year":"2016","journal-title":"J. Clin. Microbiol."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"21","DOI":"10.4314\/njpar.v41i1.4","article-title":"Prevalence of gastrointestinal parasites in captive animals in selected private zoos in south-west Nigeria","volume":"41","author":"Akinnubi","year":"2020","journal-title":"Niger. J. Parasitol."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"327","DOI":"10.1016\/j.vetpar.2008.10.103","article-title":"Natural infection by Cryptosporidium sp., Giardia sp. and Eimeria leuckarti in three groups of equines with different handlings in Rio de Janeiro, Brazil","volume":"160","author":"Souza","year":"2009","journal-title":"Vet. Parasitol."},{"key":"ref_28","doi-asserted-by":"crossref","unstructured":"Zahedi, A., Odgers, T., Ball, A., Watkinson, A., Robertson, I., and Ryan, U. (2020). Longitudinal analysis of Giardia duodenalis assemblages in animals inhabiting drinking water catchments in New South Wales and Queensland\u2014Australia (2013\u20132015). Sci. Total Environ., 718.","DOI":"10.1016\/j.scitotenv.2020.137433"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"183","DOI":"10.1016\/j.ijppaw.2020.02.002","article-title":"Not playing by the rules: Unusual patterns in the epidemiology of parasites in a natural population of feral horses (Equus caballus) on Sable Island, Canada","volume":"11","author":"Jenkins","year":"2020","journal-title":"Int. J. Parasitol. Parasites Wildl."},{"key":"ref_30","doi-asserted-by":"crossref","unstructured":"Figueiredo, A.M., K\u00f6ster, P.C., Dashti, A., Torres, R.T., Fonseca, C., Mysterud, A., Bailo, B., Carvalho, J., Ferreira, E., and Hip\u00f3lito, D. (2023). Molecular detection and distribution of Giardia duodenalis and Cryptosporidium spp. infections in wild and domestic animals in Portugal. Transbound. Emerg. Dis., 2023.","DOI":"10.1155\/2023\/5849842"},{"key":"ref_31","first-page":"814","article-title":"Frequency of Giardia spp. and Cryptosporidium spp. in domestic and captive wild animals in the north of Veracruz, Mexico","volume":"43","year":"2023","journal-title":"Pak. Vet. J."},{"key":"ref_32","first-page":"177","article-title":"Prevalence and genotyping of Giardia duodenalis among Arabian horses in Ahvaz, southwest of Iran","volume":"71","author":"Jafari","year":"2016","journal-title":"Arch. Razi Inst."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"56","DOI":"10.1016\/j.jevs.2019.06.017","article-title":"First molecular detection and phylogenetic analyses of zoonotic Giardia intestinalis in horses in Turkey","volume":"80","author":"Demircan","year":"2019","journal-title":"J. Equine Vet. Sci."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"271","DOI":"10.1093\/cid\/cis762","article-title":"A systematic review and meta-analysis of the association between Giardia lamblia and endemic pediatric diarrhea in developing countries","volume":"55","author":"Muhsen","year":"2012","journal-title":"Clin. Infect. Dis."},{"key":"ref_35","doi-asserted-by":"crossref","unstructured":"Ak\u00e7ay, S., Gurkok-Tan, T., and Ekici, S. (2025). Identification of key genes in immune-response post-endurance run in horses. J. Equine Vet. Sci., 149.","DOI":"10.1016\/j.jevs.2025.105418"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"31","DOI":"10.1016\/j.vetpar.2013.02.006","article-title":"A large scale molecular study of Giardia duodenalis in horses from Colombia","volume":"196","author":"Fayer","year":"2013","journal-title":"Vet. Parasitol."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"317","DOI":"10.1016\/j.vetpar.2005.02.011","article-title":"Molecular characterization of potentially zoonotic isolates of Giardia duodenalis in horses","volume":"130","author":"Traub","year":"2005","journal-title":"Vet. Parasitol."},{"key":"ref_38","doi-asserted-by":"crossref","unstructured":"Karim, M.R., Li, J., Rume, F.I., Sumon, S., Selim, A.S.M., Hoda, N., and Zhang, L. (2021). Occurrence and molecular characterization of Cryptosporidium spp. and Giardia duodenalis among captive mammals in the Bangladesh National Zoo. Parasitol. Int., 84.","DOI":"10.1016\/j.parint.2021.102414"},{"key":"ref_39","doi-asserted-by":"crossref","unstructured":"Sun, J., Qin, Z., Fu, Y., Qin, H., Sun, M., Dong, H., Chao, L., Zhang, L., and Li, J. (2023). Assessment of potential zoonotic transmission of Giardia duodenalis from dogs and cats. One Health, 17.","DOI":"10.1016\/j.onehlt.2023.100651"},{"key":"ref_40","doi-asserted-by":"crossref","unstructured":"Deng, L., and Tan, K.S.W. (2025). From parasite to partner: Unravelling the multifaceted role of Blastocystis in human health and disease. Lancet Microbe, 6.","DOI":"10.1016\/j.lanmic.2025.101155"},{"key":"ref_41","doi-asserted-by":"crossref","unstructured":"Lhotsk\u00e1, Z., Jirk\u016f, M., Hlo\u017ekov\u00e1, O., Bro\u017eov\u00e1, K., Jirsov\u00e1, D., Stensvold, C.R., Kol\u00edsko, M., and Jirk\u016f Pomajb\u00edkov\u00e1, K. (2020). A study on the prevalence and subtype diversity of the intestinal protist Blastocystis sp. in a gut-healthy human population in the Czech Republic. Front. Cell. Infect. Microbiol., 10.","DOI":"10.3389\/fcimb.2020.544335"}],"container-title":["Animals"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2076-2615\/16\/12\/1845\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,6,22]],"date-time":"2026-06-22T10:49:19Z","timestamp":1782125359000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2076-2615\/16\/12\/1845"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,6,15]]},"references-count":41,"journal-issue":{"issue":"12","published-online":{"date-parts":[[2026,6]]}},"alternative-id":["ani16121845"],"URL":"https:\/\/doi.org\/10.3390\/ani16121845","relation":{},"ISSN":["2076-2615"],"issn-type":[{"value":"2076-2615","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,6,15]]}}}