title: Isolation and phylogenetic analysis of avian-origin European H1N1 swine influenza viruses in Jiangsu, China.
abstract: Isolates of the A(H1N1)pdm2009 virus were first identified in asymptomatic swine in Jiangsu province, China in January 2010, indicating that the virus has retro-infected swine after circulating through humans in mainland China. The purpose of this study was to determine whether the avian-origin European H1N1 swine influenza virus (SIV) and the A(H1N1)pdm2009 virus are cocirculating in swine in Jiangsu province of China. From May 2010 to May 2011, 1,030 nasal swab samples were collected from healthy swine in Jiangsu province of China and were tested for influenza A H1N1 using reverse transcription-PCR. Fragments of the complete genomes of viruses from the samples that were positive for influenza A H1N1 were sequenced and analysed. A total of 32 avian-origin European H1N1 SIVs were isolated, and no A(H1N1)pdm2009 viruses were identified; full-length genomes of 18 strains were sequenced. The eight gene segments of some of the isolated H1N1 viruses have 99.1-99.8% sequence identity with the human A/Jiangsu/ALS1/2011(H1N1) isolates in the same region. Our study indicates that the avian-origin European H1N1 SIVs remain endemic in swine and have retro-infected humans after circulating through swine, which may present a risk factor for public health.
authors.affiliation: College of Veterinary Medicine, Yangzhou University, 12 East Wenhui Road, Yangzhou, 225009 Jiangsu, People's Republic of China.
authors.forename: Guo
authors.initials: G
authors.lastname: Zhao
authors.forename: Jinjin
authors.initials: J
authors.lastname: Pan
authors.forename: Xiaobing
authors.initials: X
authors.lastname: Gu
authors.forename: Xinlun
authors.initials: X
authors.lastname: Lu
authors.forename: Qunhui
authors.initials: Q
authors.lastname: Li
authors.forename: Jie
authors.initials: J
authors.lastname: Zhu
authors.forename: Chaoyang
authors.initials: C
authors.lastname: Chen
authors.forename: Zhiqiang
authors.initials: Z
authors.lastname: Duan
authors.forename: Quangang
authors.initials: Q
authors.lastname: Xu
authors.forename: Xiaobo
authors.initials: X
authors.lastname: Wang
authors.forename: Shunlin
authors.initials: S
authors.lastname: Hu
authors.forename: Wenbo
authors.initials: W
authors.lastname: Liu
authors.forename: Daxin
authors.initials: D
authors.lastname: Peng
authors.forename: Xiaowen
authors.initials: X
authors.lastname: Liu
authors.forename: Xiaoquan
authors.initials: X
authors.lastname: Wang
authors.forename: Xiufan
authors.initials: X
authors.lastname: Liu
mesh_terms: D000818:Animals; D002681:China; D016000:Cluster Analysis; D019143:Evolution, Molecular; D016679:Genome, Viral; D053118:Influenza A Virus, H1N1 Subtype / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification*; D008969:Molecular Sequence Data; D009666:Nose / Q000821:virology; D009976:Orthomyxoviridae Infections / Q000821:virology*; D010802:Phylogeny; D012367:RNA, Viral / Q000235:genetics*; D017422:Sequence Analysis, DNA; D013552:Swine; D013553:Swine Diseases / Q000821:virology*
chemical_list: D012367:RNA, Viral