Résumé
Objective To analyze the molecular characteristics and evolution reassortment of the complete genome of avian influenza H5N1 virus isolated in Zhejiang province in recent years. Methods Complete genomes of avian influenza H5N1 viruses isolated in Zhejiang province from 2002 to 2006 were sequenced. Molecular and evolution reassortment characterization of these virus strains were analyzed by Mega 3.0 bioinformatics software. Results Through study on the HA genes from all these strains,our data revealed that there were multiple basic amino acids at the cleavage site, which was typical for HPAIV.Compared with Gs/Guangdong/1/96,all these strains had a 20 amino acid deletion in the stalk of the NA, except for Dk/Zhejiang/2/02 and Ck/Zhejiang/8/03. Results from phylogenetic analysis showed that from2002 to 2003 the H5N1 viruses belonged to the genotype of B,W,X,Y,Z, and other genotypes were prevailed in corresponding year. However, different gene fragments of several strains belonged to different genotypes. Conclusion Recombinant might be widespread among the poultry in Zhejiang province. The genetic genes of viruses isolated after 2005, the Ck/Zhejiang/24/05 and Zhejiang/16/06 strains were almost all originated from the FJ-like genotype stably.