Abstract: In order to understand the role of the wild birds in the transmission of avian influenza viruses (AIV), fresh stool from migratory birds and resident birds in Weining Caohai acquisition were collected and detected by RT-PCR. A flu virus positive sample was detected and the haemagglutinin (HA) gene was cloned and sequenced. Results showed that the AIV was subtyped into H3 and the HA fragment was 1794 bp belonging to the Eurasian lineage, which had one open reading frame and encoded 566 amino acids including 6 potential glycosylation sites. In addition, it had conserved amino acid sequences of influenza viruses of avian origin such as A, E, L, G, Q and G at position of 154, 206, 210, 241, 242 and 244, respectively, in the receptor binding site on the HA. The deduced amino acid sequences of the HA cleavage site had a typical low pathogenic motif (PEKQTR/GLF). The result showed that the low pathogenic H3 subtype AIV strain was circulating in wild birds of Guizhou province.

Key words: H3 subtype avian influenza viruses; wild bird-origin; hemagglutinin; sequence analysis