{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,16]],"date-time":"2026-10-16T01:36:59Z","timestamp":1792114619506,"version":"4.4.0"},"reference-count":26,"publisher":"American Society for Microbiology","issue":"8","license":[{"start":{"date-parts":[[2026,8,18]],"date-time":"2026-08-18T00:00:00Z","timestamp":1787011200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"},{"start":{"date-parts":[[2026,8,18]],"date-time":"2026-08-18T00:00:00Z","timestamp":1787011200000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/journals.asm.org\/non-commercial-tdm-license"}],"funder":[{"DOI":"10.13039\/100000060","name":"National Institute of Allergy and Infectious Diseases","doi-asserted-by":"publisher","award":["75N93021C00014"],"award-info":[{"award-number":["75N93021C00014"]}],"id":[{"id":"10.13039\/100000060","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100009619","name":"Japan Agency for Medical Research and Development","doi-asserted-by":"publisher","award":["JP20wm0125002, JP223fa627001, JP22fk0108626"],"award-info":[{"award-number":["JP20wm0125002, JP223fa627001, JP22fk0108626"]}],"id":[{"id":"10.13039\/100009619","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["journals.asm.org"],"crossmark-restriction":true},"short-container-title":["J Virol"],"published-print":{"date-parts":[[2026,8,18]]},"abstract":"<jats:title>ABSTRACT<\/jats:title>\n                  <jats:sec>\n                    <jats:title\/>\n                    <jats:p>Highly pathogenic avian influenza A(H5N1) (HPAI H5N1) viruses of clade 2.3.4.4b have recently been detected in U.S. dairy cattle following multiple spillover events from avian reservoirs. In December 2025, HPAI H5N1 virus was identified in a dairy herd in Wisconsin through the National Milk Testing Strategy. Here, we report the isolation of a clade 2.3.4.4b, genotype D1.1 H5N1 virus, A\/dairy cow\/Wisconsin\/25G05743-001\/2025 (WI5743-H5N1), from bulk milk associated with the affected herd, describe its phylogenetic relationships, and assess its pathogenicity in mice. Infectious virus was recovered following blind passage in embryonated chicken eggs. Phylogenetic analysis demonstrated that WI5743-H5N1 is distinct from previously reported D1.1 viruses detected in dairy cattle in Nevada and Arizona, supporting an independent introduction into cattle, and indicating a likely local avian source. Compared with closely related avian viruses, WI5743-H5N1 encoded the mammalian-adapting substitution PB2-E627K and additional amino acid differences in HA, PB1-F2, and NS1. In mice, WI5743-H5N1 replicated efficiently in respiratory tissues and was detectable in the brain but exhibited lower lethality relative to other recent clade 2.3.4.4b, genotype B3.13 viruses. Together, these findings highlight the genetic and phenotypic diversity of HPAI H5N1 viruses infecting dairy cattle and underscore the importance of continued surveillance and functional characterization of emerging strains.<\/jats:p>\n                    <jats:sec>\n                      <jats:title>IMPORTANCE<\/jats:title>\n                      <jats:p>Highly pathogenic avian influenza A(H5N1) viruses have recently entered U.S. dairy cattle through multiple spillover events from avian reservoirs, creating new opportunities for viral adaptation in mammals. Here, we describe the isolation and characterization of a clade 2.3.4.4b, genotype D1.1 H5N1 virus from bulk milk collected during a spillover event in Wisconsin in December 2025. Phylogenetic analyses demonstrated that this virus represents an independent introduction into dairy cattle distinct from previously reported D1.1 viruses identified in Nevada and Arizona. Although the virus encoded the mammalian-adapting PB2-E627K substitution, it exhibited comparatively low lethality in mice, highlighting the complexity of mammalian adaptation and pathogenicity in H5N1 viruses. These findings expand current understanding of the genetic and phenotypic diversity of H5N1 viruses infecting dairy cattle and emphasize the importance of continued surveillance and functional characterization of emerging strains.<\/jats:p>\n                    <\/jats:sec>\n                  <\/jats:sec>","DOI":"10.1128\/jvi.00761-26","type":"journal-article","created":{"date-parts":[[2026,7,10]],"date-time":"2026-07-10T14:01:49Z","timestamp":1783692109000},"update-policy":"https:\/\/doi.org\/10.1128\/asmj-crossmark-policy-page","source":"Crossref","is-referenced-by-count":2,"title":["Isolation and characterization of a clade 2.3.4.4b genotype D1.1 H5N1 virus from dairy cattle in Wisconsin"],"prefix":"10.1128","volume":"100","author":[{"given":"Daria","family":"Mezhenskaia","sequence":"first","affiliation":[{"id":[{"id":"https:\/\/ror.org\/01y2jtd41","id-type":"ROR","asserted-by":"publisher"}],"name":"Department of Pathobiological Sciences, Influenza Research Institute, University of Wisconsin-Madison","place":["Madison, USA"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Lavanya","family":"Babujee","sequence":"additional","affiliation":[{"id":[{"id":"https:\/\/ror.org\/01y2jtd41","id-type":"ROR","asserted-by":"publisher"}],"name":"Department of Pathobiological Sciences, Influenza Research Institute, University of Wisconsin-Madison","place":["Madison, USA"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ailam","family":"Lim","sequence":"additional","affiliation":[{"id":[{"id":"https:\/\/ror.org\/01y2jtd41","id-type":"ROR","asserted-by":"publisher"}],"name":"Wisconsin Veterinary Diagnostic Laboratory, University of Wisconsin-Madison","place":["Madison, USA"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Lizheng","family":"Guan","sequence":"additional","affiliation":[{"id":[{"id":"https:\/\/ror.org\/01y2jtd41","id-type":"ROR","asserted-by":"publisher"}],"name":"Department of Pathobiological Sciences, Influenza Research Institute, University of Wisconsin-Madison","place":["Madison, USA"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Dani","family":"Nguyen","sequence":"additional","affiliation":[{"id":[{"id":"https:\/\/ror.org\/01y2jtd41","id-type":"ROR","asserted-by":"publisher"}],"name":"Department of Pathobiological Sciences, Influenza Research Institute, University of Wisconsin-Madison","place":["Madison, USA"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Chunyang","family":"Gu","sequence":"additional","affiliation":[{"id":[{"id":"https:\/\/ror.org\/01y2jtd41","id-type":"ROR","asserted-by":"publisher"}],"name":"Department of Pathobiological Sciences, Influenza Research Institute, University of Wisconsin-Madison","place":["Madison, USA"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Gabriele","family":"Neumann","sequence":"additional","affiliation":[{"id":[{"id":"https:\/\/ror.org\/01y2jtd41","id-type":"ROR","asserted-by":"publisher"}],"name":"Department of Pathobiological Sciences, Influenza Research Institute, University of Wisconsin-Madison","place":["Madison, USA"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Keith","family":"Poulsen","sequence":"additional","affiliation":[{"id":[{"id":"https:\/\/ror.org\/01y2jtd41","id-type":"ROR","asserted-by":"publisher"}],"name":"Wisconsin Veterinary Diagnostic Laboratory, University of Wisconsin-Madison","place":["Madison, USA"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2231-3107","authenticated-orcid":true,"given":"Amie J.","family":"Eisfeld","sequence":"additional","affiliation":[{"id":[{"id":"https:\/\/ror.org\/01y2jtd41","id-type":"ROR","asserted-by":"publisher"}],"name":"Department of Pathobiological Sciences, Influenza Research Institute, University of Wisconsin-Madison","place":["Madison, USA"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5061-8296","authenticated-orcid":true,"given":"Yoshihiro","family":"Kawaoka","sequence":"additional","affiliation":[{"id":[{"id":"https:\/\/ror.org\/01y2jtd41","id-type":"ROR","asserted-by":"publisher"}],"name":"Department of Pathobiological Sciences, Influenza Research Institute, University of Wisconsin-Madison","place":["Madison, USA"]},{"id":[{"id":"https:\/\/ror.org\/057zh3y96","id-type":"ROR","asserted-by":"publisher"}],"name":"Department of Virology, Institute of Medical Science, University of Tokyo","place":["Tokyo, Japan"]},{"id":[{"id":"https:\/\/ror.org\/057zh3y96","id-type":"ROR","asserted-by":"publisher"}],"name":"The University of Tokyo Pandemic Preparedness, Infection and Advanced Research Center (UTOPIA), University of Tokyo","place":["Tokyo, Japan"]},{"name":"International Virus Infectious Disease Research Center, National Institute of Global Health and Medicine, Japan Institute for Health Security","place":["Tokyo, Japan"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"235","reference":[{"key":"e_1_3_4_2_2","doi-asserted-by":"publisher","DOI":"10.1128\/jvi.02209-24"},{"key":"e_1_3_4_3_2","unstructured":"WHO Global Influenza Programme. 2025. Avian influenza A(H5N1) virus. WHO. Available from: https:\/\/www.who.int\/teams\/global-influenza-programme\/avian-influenza\/avian-a-h5n1-virus. Retrieved 14 Mar 2025."},{"key":"e_1_3_4_4_2","doi-asserted-by":"publisher","DOI":"10.1128\/jvi.00052-25"},{"key":"e_1_3_4_5_2","doi-asserted-by":"publisher","DOI":"10.1038\/s44298-025-00138-5"},{"key":"e_1_3_4_6_2","doi-asserted-by":"publisher","DOI":"10.1038\/s41586-024-08054-z"},{"key":"e_1_3_4_7_2","unstructured":"USDA APHIS. 2025. HPAI confirmed cases in livestock. USDA APHIS. Available from: https:\/\/www.aphis.usda.gov\/livestock-poultry-disease\/avian\/avian-influenza\/hpai-detections\/hpai-confirmed-cases-livestock. Retrieved 15 Oct 2025."},{"key":"e_1_3_4_8_2","unstructured":"USDA APHIS. 2026. National milk testing strategy. USDA APHIS. Available from: https:\/\/www.aphis.usda.gov\/livestock-poultry-disease\/avian\/avian-influenza\/hpai-detections\/livestock\/nmts. Retrieved 14 Mar 2025."},{"key":"e_1_3_4_9_2","unstructured":"USDA APHIS. 2025. APHIS confirms D1.1 genotype in dairy cattle in Nevada. USDA APHIS. Available from: https:\/\/www.aphis.usda.gov\/news\/program-update\/aphis-confirms-d11-genotype-dairy-cattle-nevada-0. Retrieved 04 Sep 2025."},{"key":"e_1_3_4_10_2","unstructured":"USDA APHIS. 2025. APHIS identifies third HPAI spillover in dairy cattle. USDA APHIS. Available from: https:\/\/www.aphis.usda.gov\/news\/program-update\/aphis-identifies-third-hpai-spillover-dairy-cattle. Retrieved 04 Sep 2025."},{"key":"e_1_3_4_11_2","doi-asserted-by":"publisher","DOI":"10.1126\/science.adq0900"},{"key":"e_1_3_4_12_2","unstructured":"USDA APHIS. 2025. USDA confirms highly pathogenic avian influenza in a dairy herd in Wisconsin. USDA APHIS. Available from: https:\/\/www.aphis.usda.gov\/news\/agency-announcements\/usda-confirms-highly-pathogenic-avian-influenza-dairy-herd-wisconsin. 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Epidemiological bulletin: 2024 highly pathogenic avian influenza (H5N1) livestock event \u2013 Nevada and Arizona H5N1 D1.1 HPAI dairy investigation. USDA APHIS. Available from: https:\/\/www.aphis.usda.gov\/sites\/default\/files\/20250611-epi-brief-nevada-arizona-h5n1-dairy.pdf. Retrieved 03 Apr 2025."}],"container-title":["Journal of Virology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/journals.asm.org\/doi\/pdf\/10.1128\/jvi.00761-26","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/journals.asm.org\/doi\/pdf\/10.1128\/jvi.00761-26","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,8,18]],"date-time":"2026-08-18T13:04:32Z","timestamp":1787058272000},"score":1,"resource":{"primary":{"URL":"https:\/\/journals.asm.org\/doi\/10.1128\/jvi.00761-26"}},"subtitle":[],"editor":[{"given":"Stacey","family":"Schultz-Cherry","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"editor"}]}],"short-title":[],"issued":{"date-parts":[[2026,8,18]]},"references-count":26,"journal-issue":{"issue":"8","published-print":{"date-parts":[[2026,8,18]]}},"alternative-id":["10.1128\/jvi.00761-26"],"URL":"https:\/\/doi.org\/10.1128\/jvi.00761-26","relation":{},"ISSN":["0022-538X","1098-5514"],"issn-type":[{"value":"0022-538X","type":"print"},{"value":"1098-5514","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,8,18]]},"assertion":[{"value":"2026-05-14","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2026-06-22","order":2,"name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}},{"value":"2026-07-10","order":3,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}],"article-number":"e00761-26"}}