Phylogenetic Analysis on Two Strains of H5N6 Subtype Avian Influenza Virus
In order to understand the genetic evolution characteristics of avian influenza virus(AIV),the experiment sequenced the whole genome of two strains of duck-derived H5N6 subtype AIV isolated from live poultry markets in Hunan and Fujian,China,from 2022 to 2023.Then,the key amino acid loci was analyzed and the phylogenetic tree was conducted.The two strains were A/duck/Hunan/QG3/2022(H5N6)(HN/QG3)and A/duck/Fujian/QG4/2023(H5N6)(FJ/QG4),respectively.The results showed that the HN/QG3 strain belonged to clade 2.3.4.4b,and its genome was derived from H5N6 and H5N8 strains,with high homology to H5 subtype AIVs of duck,wild bird,environment and human origins.However,the FJ/QG4 strain belonged to clade 2.3.4.4h,with 97%homology of the HA gene to A/Rattus norvegicus/China/FS21/2021(H5N6)strain,while the other gene fragments showed higher homogenicity to the human-derived H5N6 subtype AIV isolated in Guangdong in 2021.In addition,the cleavage site of the HA protein of the two H5N6 subtype AIVs contained multiple basic amino acids,consistent with the molecular features of highly pathogenic avian influenza virus.Sites 226 and 228 of the HA amino acid sequence of the two H5N6 subtype strains were Q and G,respectively,suggesting that the viruses had the characteristics of preferentially binding to the avian α2,3-sialic acid receptor.Moreover,the two H5N6 subtype sttrains with 11 amino acid deletions at positions 58 to 68 of the NA protein might enhance the pathogenicity of mice.The results suggested that the two H5N6 subtype AIVs belonged to 2.3.4.4b branch and 2.3.4.4h branch,respectively,and their recognition ability of human α2,6-sialic acid receptor might be enhanced,and their virulence and transmission ability might be enhanced.
万方数据
维普
