title: A novel genotype H9N2 influenza virus possessing human H5N1 internal genomes has been circulating in poultry in eastern China since 1998.
abstract: Many novel reassortant influenza viruses of the H9N2 genotype have emerged in aquatic birds in southern China since their initial isolation in this region in 1994. However, the genesis and evolution of H9N2 viruses in poultry in eastern China have not been investigated systematically. In the current study, H9N2 influenza viruses isolated from poultry in eastern China during the past 10 years were characterized genetically and antigenically. Phylogenetic analysis revealed that these H9N2 viruses have undergone extensive reassortment to generate multiple novel genotypes, including four genotypes (J, F, K, and L) that have never been recognized before. The major H9N2 influenza viruses represented by A/Chicken/Beijing/1/1994 (Ck/BJ/1/94)-like viruses circulating in poultry in eastern China before 1998 have been gradually replaced by A/Chicken/Shanghai/F/1998 (Ck/SH/F/98)-like viruses, which have a genotype different from that of viruses isolated in southern China. The similarity of the internal genes of these H9N2 viruses to those of the H5N1 influenza viruses isolated from 2001 onwards suggests that the Ck/SH/F/98-like virus may have been the donor of internal genes of human and poultry H5N1 influenza viruses circulating in Eurasia. Experimental studies showed that some of these H9N2 viruses could be efficiently transmitted by the respiratory tract in chicken flocks. Our study provides new insight into the genesis and evolution of H9N2 influenza viruses and supports the notion that some of these viruses may have been the donors of internal genes found in H5N1 viruses.
authors: Animal Infectious Disease Laboratory, College of Veterinary Medicine, Yangzhou University, 48 East Wenhui Road, Yangzhou, Jiangsu 225009, China.
authors: Pinghu
authors: P
authors: Zhang
authors: Yinghua
authors: Y
authors: Tang
authors: Xiaowen
authors: X
authors: Liu
authors: Wenbo
authors: W
authors: Liu
authors: Xiaorong
authors: X
authors: Zhang
authors: Hongqi
authors: H
authors: Liu
authors: Daxin
authors: D
authors: Peng
authors: Song
authors: S
authors: Gao
authors: Yantao
authors: Y
authors: Wu
authors: Luyong
authors: L
authors: Zhang
authors: Shan
authors: S
authors: Lu
authors: Xiufan
authors: X
authors: Liu
mesh_terms: D000818:Animals; D002681:China; D016000:Cluster Analysis; D019143:Evolution, Molecular; D005838:Genotype; D053124:Influenza A Virus, H5N1 Subtype / Q000235:genetics*; D053127:Influenza A Virus, H9N2 Subtype / Q000235:genetics*; D005585:Influenza in Birds / Q000821:virology*; D008969:Molecular Sequence Data; D010802:Phylogeny; D011200:Poultry; D016865:Reassortant Viruses / Q000145:classification* / Q000235:genetics* / Q000276:immunology / Q000302:isolation & purification; D017422:Sequence Analysis, DNA; D012703:Serotyping