Chothe Shubhada K, Srinivas Surabhi, Misra Sougat, Nallipogu Noel Chandan, Gilbride Elizabeth, LaBella Lindsey, Mukherjee Swastidipa, Gauthier Christian H, Pecoraro Heidi L, Webb Brett T, Pipas James M, Ramasamy Santhamani, Kuchipudi Suresh V
Department of Infectious Diseases and Microbiology, School of Public Health, University of Pittsburgh, Pittsburgh, PA, USA.
Center for Vaccine Research, University of Pittsburgh, Pittsburgh, PA, USA.
Emerg Microbes Infect. 2025 Dec;14(1):2440498. doi: 10.1080/22221751.2024.2440498. Epub 2024 Dec 17.
In April 2024, ten cats died in a rural South Dakota (SD) residence, showing respiratory and neurological symptoms. Necropsy and laboratory testing of two cats confirmed H5N1 clade 2.3.4.4b infection. The viral genome sequences are closely related to recent SD cattle H5N1 sequences. Cat H5N1 genomes had unique mutations, including T143A in haemagglutinin, known to affect infectivity and immune evasion, and two novel mutations in PA protein (F314L, L342Q) that may affect polymerase activity and virulence, suggesting potential virus adaptation. Dead cats showed systemic infection with lesions and viral antigens in multiple organs. Higher viral RNA and antigen in the brain indicated pronounced neurotropism. Lectin-histochemistry revealed widespread co-expression of sialic acid α-2,6 and α-2,3 receptors, suggesting cats could serve as mixing vessels for reassortment of avian and mammalian influenza viruses. No differences in clade 2.2 or 2.3.4.4b H5 pseudoviruses binding to cat lung/brain tissues indicated the neurotropism is unlikely mediated by receptor binding affinity.
2024年4月，南达科他州（SD）农村地区的10只猫死亡，表现出呼吸道和神经症状。对其中两只猫进行尸检和实验室检测，确认感染了H5N1进化分支2.3.4.4b。病毒基因组序列与南达科他州近期牛的H5N1序列密切相关。猫H5N1基因组有独特的突变，包括血凝素中的T143A，已知其会影响传染性和免疫逃逸，以及PA蛋白中的两个新突变（F314L、L342Q），可能影响聚合酶活性和毒力，提示病毒可能发生了适应性变化。死亡的猫表现为全身感染，多个器官出现病变和病毒抗原。脑中较高的病毒RNA和抗原表明有明显的嗜神经性。凝集素组织化学显示唾液酸α-2,6和α-2,3受体广泛共表达，提示猫可能是禽流感病毒和哺乳动物流感病毒重配的混合载体。2.2或2.3.4.4b进化分支的H5假病毒与猫肺/脑组织结合无差异，表明嗜神经性不太可能由受体结合亲和力介导。
