Abstract:

One H6N5 subtype avian influenza virus, A/duck/Yangzhou/013/2008 (Dk/YZ/013/08), was isolated from aquatic birds in some live bird market in East China during our epidemiological surveillance and was identified by HA/HI test and specific RTPCR test. To investigate the biological role of H6N5 avian influenza viruses in the influenza ecology, Dk/YZ/013/08 was subjected to genome sequencing. All the complete genome sequences of H6N5 subtype influenza viruses available in GenBank and some other reference sequences were retrieved to do the phylogenetic analysis with Dk/YZ/013/08. The results indicated that the HA gene showed 94% nucleotide identity with A/duck/Kingmen/E322/2004(H6N2) isolated from Taiwan Province of China, and the amino acid motif of cleavage site between HA1 and HA2 of Dk/YZ/013/08 was “PQIETRG”, which was the typical characterization of the LPAIV. The NA gene of Dk/YZ/013/08 had close relationship with A/mallard/Switzerland/WV4060167/2006(H3N5). However, the PB2 gene displayed 97.3% similarity with A/duck/Zhejiang/11/2000(H5N1) and clustered with A/goose/Guangdong/1/1996(H5N1). Our results indicated that Dk/YZ/013/08 may be a reassortant virus by introducing its PB2 gene from H5N1 subtype influenza virus.