title: Differences in transmissibility and pathogenicity of reassortants between H9N2 and 2009 pandemic H1N1 influenza A viruses from humans and swine.
abstract: Both H9N2 subtype avian influenza and 2009 pandemic H1N1 viruses (pH1N1) can infect humans and pigs, which provides the opportunity for virus reassortment, leading to the genesis of new strains with potential pandemic risk. In this study, we generated six reassortant H9 viruses in the background of three pH1N1 strains from different hosts (A/California/04/2009 [CA04], A/Swine/Jiangsu/48/2010 [JS48] and A/Swine/Jiangsu/285/2010 [JS285]) by replacing either the HA (H9N1-pH1N1) or both the HA and NA genes (H9N2-pH1N1) from an h9.4.2.5-lineage H9N2 subtype influenza virus, A/Swine/Taizhou/5/08 (TZ5). The reassortant H9 viruses replicated to higher titers in vitro and in vivo and gained both efficient transmissibility in guinea pigs and increased pathogenicity in mice compared with the parental H9N2 virus. In addition, differences in transmissibility and pathogenicity were observed among these reassortant H9 viruses. The H9N2-pH1N1viruses were transmitted more efficiently than the corresponding H9N1-pH1N1 viruses but showed significantly decreased pathogenicity. One of the reassortant H9 viruses that were generated, H9N-JS48, showed the highest virulence in mice and acquired respiratory droplet transmissibility between guinea pigs. These results indicate that coinfection of swine with H9N2 and pH1N1viruses may pose a threat for humans if reassortment occurs, emphasizing the importance of surveillance of these viruses in their natural hosts.
authors: College of Veterinary Medicine, Yangzhou University, 12 East Wenhui Road, Yangzhou, 225009, Jiangsu, People's Republic of China.
authors: Liang
authors: L
authors: He
authors: Qiwen
authors: Q
authors: Wu
authors: Kaijun
authors: K
authors: Jiang
authors: Zhiqiang
authors: Z
authors: Duan
authors: Jingjing
authors: J
authors: Liu
authors: Haixu
authors: H
authors: Xu
authors: Zhu
authors: Z
authors: Cui
authors: Min
authors: M
authors: Gu
authors: Xiaoquan
authors: X
authors: Wang
authors: Xiaowen
authors: X
authors: Liu
authors: Xiufan
authors: X
authors: Liu
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002460:Cell Line; D004285:Dogs; D005260:Female; D015967:Gene Expression Regulation, Viral; D006168:Guinea Pigs; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype / Q000235:genetics / Q000472:pathogenicity*; D053127:Influenza A Virus, H9N2 Subtype / Q000235:genetics / Q000472:pathogenicity*; D007251:Influenza, Human / Q000453:epidemiology / Q000635:transmission / Q000821:virology*; D051379:Mice; D008807:Mice, Inbred BALB C; D009976:Orthomyxoviridae Infections / Q000662:veterinary* / Q000821:virology; D010802:Phylogeny; D016865:Reassortant Viruses / Q000235:genetics / Q000472:pathogenicity*; D011956:Receptors, Cell Surface / Q000378:metabolism; D013552:Swine; D013553:Swine Diseases / Q000821:virology*; D014764:Viral Proteins / Q000235:genetics / Q000378:metabolism; D014779:Virus Replication
chemical_list: D011956:Receptors, Cell Surface; D014764:Viral Proteins