{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,26]],"date-time":"2026-09-26T12:22:21Z","timestamp":1790425341006,"version":"4.1.0"},"reference-count":43,"publisher":"MDPI AG","issue":"7","license":[{"start":{"date-parts":[[2019,7,5]],"date-time":"2019-07-05T00:00:00Z","timestamp":1562284800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Viruses"],"abstract":"<jats:p>An equine foamy virus (EFV) was isolated for the first time in Japan from peripheral blood mononuclear cells of a broodmare that showed wobbler syndrome after surgery for intestinal volvulus and the isolate was designated as EFVeca_LM. Complete nucleotide sequences of EFVeca_LM were determined. Nucleotide sequence analysis of the long terminal repeat (LTR) region, gag, pol, env, tas, and bel2 genes revealed that EFVeca_LM and the EFV reference strain had 97.2% to 99.1% identities. For a sero-epidemiological survey, indirect immunofluorescent antibody tests were carried out using EFVeca_LM-infected cells as an antigen against 166 sera of horses in five farms collected in 2001 to 2002 and 293 sera of horses in eight farms collected in 2014 to 2016 in Hokkaido, Japan. All of the farms had EFV antibody-positive horses, and average positive rates were 24.6% in sera obtained in 2001 to 2002 and 25.6% in sera obtained in 2014 to 2016 from broodmare farms. The positive rate in a stallion farm (Farm A) in 2002 was 10.7%, and the positive rates in two stallion farms, Farms A and B, in 2015 were 40.9% and 13.3%, respectively. The results suggested that EFV infection is maintained widely in horses in Japan.<\/jats:p>","DOI":"10.3390\/v11070613","type":"journal-article","created":{"date-parts":[[2019,7,5]],"date-time":"2019-07-05T11:44:16Z","timestamp":1562327056000},"page":"613","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":5,"title":["Isolation of an Equine Foamy Virus and Sero-Epidemiology of the Viral Infection in Horses in Japan"],"prefix":"10.3390","volume":"11","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-6360-9169","authenticated-orcid":false,"given":"Rikio","family":"Kirisawa","sequence":"first","affiliation":[{"name":"Laboratory of Veterinary Virology, Department of Pathobiology, School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Hokkaido 069-8501, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yuko","family":"Toishi","sequence":"additional","affiliation":[{"name":"Shadai Stallion Station, Abira-cho, Hokkaido 059-1432, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hiromitsu","family":"Hashimoto","sequence":"additional","affiliation":[{"name":"Shiraoi Farm, Shiraoi-cho, Hokkaido 059-0901, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Nobuo","family":"Tsunoda","sequence":"additional","affiliation":[{"name":"Shadai Stallion Station, Abira-cho, Hokkaido 059-1432, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2019,7,5]]},"reference":[{"key":"ref_1","unstructured":"Knipe, D.M., and Howley, P. (2013). Foamy viruses. Fields Virology, Lippincott, Willilams & Wilkins. [6th ed.]."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1093\/infdis\/109.1.1","article-title":"A second immunologic type of simian foamy virus: Monkey throat infections and unmasking by both types","volume":"109","author":"Johnston","year":"1961","journal-title":"J. Infect. Dis."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"1350","DOI":"10.1038\/2011350a0","article-title":"Comparison of simian foamy virus strains including a new serological type","volume":"201","author":"Stiles","year":"1964","journal-title":"Nature"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"446","DOI":"10.1038\/216446a0","article-title":"Latent viruses in chimpanzees with experimental kuru","volume":"216","author":"Rogers","year":"1967","journal-title":"Nature"},{"key":"ref_5","first-page":"299","article-title":"An unusual virus in cultures from a human nasopharyngeal carcinoma","volume":"46","author":"Achong","year":"1971","journal-title":"J. Natl. Cancer Inst."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"1190","DOI":"10.1038\/2221190a0","article-title":"Syncytium-forming agent isolated from domestic cats","volume":"222","author":"Riggs","year":"1969","journal-title":"Nature"},{"key":"ref_7","first-page":"188","article-title":"Isolation, immunodiffusion, immunofluorescence, and electron microscopy of a syncytial virus of lymphosarcomatous and apparently normal cattle","volume":"29","author":"Malmquist","year":"1969","journal-title":"Cancer Res."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"4064","DOI":"10.1128\/JVI.74.9.4064-4073.2000","article-title":"Isolation and characterization of an equine foamy virus","volume":"74","author":"Bittoun","year":"2000","journal-title":"J. Virol."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"10999","DOI":"10.1128\/JVI.01394-12","article-title":"Virome analysis for identification of novel mammalian viruses in bat species from Chinese provinces","volume":"86","author":"Wu","year":"2012","journal-title":"J. Virol."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"165","DOI":"10.1128\/CMR.14.1.165-176.2001","article-title":"Historical perspective of foamy virus epidemiology and infection","volume":"14","author":"Meiering","year":"2001","journal-title":"Clin. Microbiol. Rev."},{"key":"ref_11","first-page":"197","article-title":"Non-primate foamy viruses","volume":"277","year":"2003","journal-title":"Curr. Top. Microbiol. Immunol."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"284","DOI":"10.1016\/S0966-842X(00)01763-7","article-title":"Why aren\u2019t foamy viruses pathogenic?","volume":"8","author":"Linial","year":"2000","journal-title":"Trends Microbiol."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"2349","DOI":"10.3390\/v5102349","article-title":"Evolution of foamy viruses: The most ancient of all retroviruses","volume":"5","author":"Rethwilm","year":"2013","journal-title":"Viruses"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"2169","DOI":"10.3390\/v5092169","article-title":"Non-simian foamy viruses: Molecular virology, tropism and prevalence and zoonotic\/interspecies transmission","volume":"5","author":"Kehl","year":"2013","journal-title":"Viruses"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"921","DOI":"10.1292\/jvms.62.921","article-title":"Contrastive prevalence of feline retrovirus infections between northern and southern Vietnam","volume":"62","author":"Nakamura","year":"2000","journal-title":"J. Vet. Med. Sci."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"337","DOI":"10.1016\/0165-2427(92)90020-Q","article-title":"Prevalence of feline immunodeficiency virus and other retroviral infections in sick cats in Italy","volume":"31","author":"Bandecchi","year":"1992","journal-title":"Vet. Immunol. Immunopathol."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"161","DOI":"10.1292\/jvms.57.161","article-title":"Seroepidemiological survey of feline retrovirus infections in cats in Taiwan in 1993 and 1994","volume":"57","author":"Lin","year":"1995","journal-title":"J. Vet. Med. Sci."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"121","DOI":"10.7589\/0090-3558-35.1.121","article-title":"Feline viruses in wildcats from Scotland","volume":"35","author":"Daniels","year":"1999","journal-title":"J. Wildl. Dis."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"2883","DOI":"10.1128\/jcm.35.11.2883-2885.1997","article-title":"Seroprevalence of Bartonella henselae infection and correlation with disease status in cats in Switzerland","volume":"35","author":"Glaus","year":"1997","journal-title":"J. Clin. Microbiol."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"2848","DOI":"10.1128\/JCM.37.9.2848-2851.1999","article-title":"Epidemiology of feline foamy virus and feline immunodeficiency virus infections in domestic and feral cats: A seroepidemiological study","volume":"37","author":"Winkler","year":"1999","journal-title":"J. Clin. Microbiol."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"236","DOI":"10.7589\/0090-3558-26.2.236","article-title":"Serological survey of the Iriomote cat (Felis iriomotensis) in Japan","volume":"26","author":"Mochizuki","year":"1990","journal-title":"J. Wildl. Dis."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"1273","DOI":"10.1292\/jvms.60.1273","article-title":"Seroepidemiological survey of feline retrovirus infections in domestic and leopard cats in northern Vietnam in 1997","volume":"60","author":"Miyazawa","year":"1998","journal-title":"J. Vet. Med. Sci."},{"key":"ref_23","first-page":"271","article-title":"A serological survey of bovine syncytial virus in Ontario: Associations with bovine leukemia and immunodeficiency-like viruses, production records, and management practices","volume":"59","author":"Jacobs","year":"1995","journal-title":"Can. J. Vet. Res."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"25","DOI":"10.1016\/0378-1135(88)90124-1","article-title":"Epidemiological studies of bovine spumavirus","volume":"16","author":"Johnson","year":"1988","journal-title":"Vet. Microbiol."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"123","DOI":"10.1016\/j.virol.2007.03.009","article-title":"Serological detection systems for identification of cows shedding bovine foamy virus via milk","volume":"364","author":"Romen","year":"2007","journal-title":"Virology"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"247","DOI":"10.1515\/jvetres-2017-0034","article-title":"Development of a recombinant protein-based ELISA for detection of antibodies against bovine foamy virus","volume":"61","author":"Rudzki","year":"2017","journal-title":"J. Vet. Res."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"11","DOI":"10.1007\/BF01316881","article-title":"The genomic diversity among equine herpesvirus-1 strains isolated in Japan","volume":"129","author":"Kirisawa","year":"1993","journal-title":"Arch. Virol."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"197","DOI":"10.1016\/S0165-2427(98)00099-3","article-title":"Enzymatic amplification and expression of bovine interleukin-1 receptor antagonist cDNA","volume":"62","author":"Kirisawa","year":"1998","journal-title":"Vet. Immunol. Immunopathol."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"503","DOI":"10.1016\/S0022-2836(75)80083-0","article-title":"Detection of specific sequences among DNA fragments separated by gel electrophoresis","volume":"98","author":"Southern","year":"1975","journal-title":"J. Mol. Biol."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"1870","DOI":"10.1093\/molbev\/msw054","article-title":"MEGA7: Molecular evolutionary genetics analysis version 7.0 for bigger datasets","volume":"33","author":"Kumar","year":"2016","journal-title":"Mol. Biol. Evol."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"111","DOI":"10.1007\/BF01731581","article-title":"A simple method for estimating evolutionary rates of base substitutions through comparative studies of nucleotide sequences","volume":"16","author":"Kimura","year":"1980","journal-title":"J. Mol. Evol."},{"key":"ref_32","first-page":"125","article-title":"Isolation of foamy viruses from peripheral blood lymphocytes","volume":"304","author":"Bittoun","year":"2005","journal-title":"Methods Mol. Biol."},{"key":"ref_33","first-page":"917","article-title":"Isolation of bovine syncytial virus in East Germany","volume":"35","author":"Liebermann","year":"1981","journal-title":"Arch. Exp. Veterinarmed."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"5855","DOI":"10.3390\/v7112907","article-title":"In vitro evolution of bovine foamy virus variants with enhanced cell-free virus titers and transmission","volume":"7","author":"Bao","year":"2015","journal-title":"Viruses"},{"key":"ref_35","doi-asserted-by":"crossref","unstructured":"Zhang, S., Liu, X., Liang, Z., Bing, T., Qiao, W., and Tan, J. (2019). The influence of envelope C-terminus amino acid composition on the ratio of cell-free to cell-cell transmission for bovine foamy virus. Viruses, 11.","DOI":"10.3390\/v11020130"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"1604","DOI":"10.1292\/jvms.18-0121","article-title":"Isolation of bovine foamy virus in Japan","volume":"80","author":"Hachiya","year":"2018","journal-title":"J. Vet. Med. Sci."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"778","DOI":"10.1128\/jvi.71.1.778-784.1997","article-title":"A sorting motif localizes the foamy virus glycoprotein to the endoplasmic reticulum","volume":"71","author":"Goepfert","year":"1997","journal-title":"J. Virol."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"7210","DOI":"10.1128\/JVI.73.9.7210-7217.1999","article-title":"An endoplasmic reticulum retrieval signal partitions human foamy virus maturation to intracytoplasmic membranes","volume":"73","author":"Goepfert","year":"1999","journal-title":"J. Virol."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"171","DOI":"10.1016\/S0168-1702(01)00275-1","article-title":"Genetic analyses of feline foamy virus isolates from domestic and wild feline species in geographically distinct areas","volume":"76","author":"Phung","year":"2001","journal-title":"Virus Res."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"53","DOI":"10.1007\/BF01310964","article-title":"Detection and prevalence of serotypes of feline syncytial spumaviruses","volume":"83","author":"Flower","year":"1985","journal-title":"Arch. Virol."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"144","DOI":"10.1006\/viro.1998.9232","article-title":"Detection and molecular characterisation of feline foamy virus serotypes in naturally infected cats","volume":"247","author":"Winkler","year":"1998","journal-title":"Virology"},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"10905","DOI":"10.1128\/JVI.01875-12","article-title":"Complete genome sequences of two novel European clade bovine foamy viruses from Germany and Poland","volume":"86","author":"Hechler","year":"2012","journal-title":"J. Virol."},{"key":"ref_43","unstructured":"Materniak, M., and Kuzmak, J. (2012, January 29\u201330). Occurrence of equine foamy virus infection in horses from Poland. Proceedings of the 9th International Foamy Conference, Bethesda, MD, USA."}],"container-title":["Viruses"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1999-4915\/11\/7\/613\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T13:02:52Z","timestamp":1760187772000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1999-4915\/11\/7\/613"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2019,7,5]]},"references-count":43,"journal-issue":{"issue":"7","published-online":{"date-parts":[[2019,7]]}},"alternative-id":["v11070613"],"URL":"https:\/\/doi.org\/10.3390\/v11070613","relation":{},"ISSN":["1999-4915"],"issn-type":[{"value":"1999-4915","type":"electronic"}],"subject":[],"published":{"date-parts":[[2019,7,5]]}}}