Clade 2.3.4.4b H5N8 Subtype Avian Influenza Viruses Were Identified from the Common Crane Wintering in Yunnan Province, China

Abstract

The seasonal migration of wild aquatic birds plays a critical role in the maintenance, transmission, and incursion of the avian influenza virus (AIV). AIV surveillance was performed during 2020–2021 in two national nature reserves with abundant wild bird resources in Yunnan, China. Four H5N8 AIVs isolates from the common crane were identified by next-generation sequencing. Phylogenetic analysis demonstrated that all eight gene segments of these H5N8 AIVs belonged to clade 2.3.4.4b high-pathogenic AIV (HPAIV) and shared high nucleotide sequence similarity with the strains isolated in Hubei, China, and Siberia, Russia, in 2020–2021. The H5N8 HPAIVs from common cranes were characterized by both human and avian dual-receptor specificity in the hemagglutinin (HA) protein. Moreover, possessing the substitutions contributes to overcoming transmission barriers of mammalian hosts in polymerase basic 2 (PB2), polymerase basic protein 1 (PB1), and polymerase acid (PA), and exhibiting the long stalk in the neck region of the neuraminidase (NA) protein contributes to adaptation in wild birds. Monitoring AIVs in migratory birds, at stopover sites and in their primary habitats, i.e., breeding or wintering grounds, could provide insight into potential zoonosis caused by AIVs.

Diversity of genotypes and pathogenicity of H9N2 avian influenza virus derived from wild bird and domestic poultry

“…Actively monitoring the prevalence and evolution of influenza viruses will contribute to the development of prevention and control measures against the influenza epidemic. In this study, 11 isolates of H9N2 were identified in our annual surveillance for AIV in Dashanbao Black-Necked Crane National Nature Reserve and Huize Black-Necked Crane National Reserve, in Yunnan Province, China, from the fecal samples of wild birds and surrounding domestic poultry during 2021-2022 (Yang et al, 2022). The viral phylogenetic analysis revealed distinct genotypes between strains obtained from wild birds and domestic birds.…”

“…In this study, 11 H9N2 AIV isolates were analyzed, including four from common crane (Grus grus), two from bar-headed goose (Anser indicus) and five from domestic poultry (Gallus gallus). These isolates had been previously identified during our AIV surveillance at the Dashanbao Black-Necked Crane National Nature Reserve and the Huize Black-Necked Crane National Reserve, in Yunnan Province, China (Yang et al, 2022). The identification procedures for the H9N2 AIV isolates were as follows: initially, fresh samples were propagated in chicken embryos, and the allantoic fluid was tested using the hemagglutination assay.…”

“…H9N2 has been detected in various bird species, including chickens, ducks, quails, pheasants, partridges, guinea fowl, pigeons, green peafowl, as well as wild birds (Guo et al, 2021;Wang et al, 2023). Wild aquatic birds, with their gastrointestinal viral tropism and cloacal route of viral shedding, are considered as the primary natural reservoir for AIV (Homme and Easterday, 1970;Yang et al, 2022). Billions of poultry birds are raised in China every year under the traditional small-scale and backyard-level raising model with limited biosecurity measures (Liu et al, 2020;Xue et al, 2023).…”

Genomic and Pathologic Characterization of the First FAdV-C Serotype 4 Isolate from Black-Necked Crane

“…A total of 814 fecal samples were collected from wading birds in the natural reserves in Yunnan Province, China. Detailed information regarding sample collection was given in a previous study [ 10 ].…”

“…Considering the prevalence of FAdVs in domestic poultry in China, and their potential for cross-species transmission, we conducted a surveillance of FAdVs in wild birds as part of a comprehensive virus surveillance program on wildfowls in Yunnan Province, China, initiated by the local administrative department of wildlife conservation [ 10 ]. Specifically, a strain of FAdV-4 was successfully isolated from a fecal sample of black-necked crane ( Grus nigricollis ).…”