Genetic Evolution of Six Avian H3 Subtype Influenza Viruses from 2019 to 2021 in Eastern China
H3 subtype influenza virus exists widely in nature and infects many hosts such as human,pig,horse,dog and poultry.As the virus can spread across species,its harm cannot be ignored.In this study,throat and cloacal swab samples were collected from 2019 to 2021 from apparently healthy chickens at live poultry markets in Eastern China.Six representative strains were selected from the waterfowl isolates of H3 subtype influenza viruses that had been identified by serological tests.RT-PCR test further revealed that five strains were H3N2 and the other strain was H3N1 subtype.Subsequently,whole genome sequencing,homology comparison and evolutionary analysis were conducted on the six H3 isolates.The results showed that the cleavage site of HA protein was uniformly PEKQTR/GLF without consecutive basic amino acids,and consistent with the molecular feature of low pathogenic Avian influenza virus(AIV).The receptor binding sites were all of avian-specific 226Q and 228S,suggesting a low potential for interspecies transmission to mammals.We found that the internal genes were of diverse sources and the six H3 subtype AIVs were closely related to many other subtypes including H3N8,H4N6,H5N8,H6N1,H7N7,H0N3 and so on.Except that the NS genes of JS1018/19 and JS1094/19 belonged to the North American lineage,other viruses were all of Avian Eurasian lineage that were distantly related to the mammalian strains of canine,horse,swine and human origin.Such analysis indicated the possible gene reassortment between different evolutionary lineages but not the gene exchange from avian to mammalian hosts.These results in this study would enrich the epidemiological data of H3 subtype AIVs and provided a reference for further understanding the distribution characteristics of low pathogenic AIVs in China.
国家科技期刊平台
NSTL
万方数据
