Virologica Sinica

, Volume 27, Issue 5, pp 292–298 | Cite as

Molecular characterization of avian-like H1N1 swine influenza a viruses isolated in Eastern China, 2011

  • Xian Qi
  • Yuning Pan
  • Yuanfang Qin
  • Rongqiang Zu
  • Fengyang Tang
  • Minghao Zhou
  • Hua WangEmail author
  • Yongchun Song
Research Article


Currently, three predominant subtypes of influenza virus are prevalent in pig populations worldwide: H1N1, H3N2, and H1N2. European avian-like H1N1 viruses, which were initially detected in European pig populations in 1979, have been circulating in pigs in eastern China since 2007. In this study, six influenza A viruses were isolated from 60 swine lung samples collected from January to April 2011 in eastern China. Based on whole genome sequencing, molecular characteristics of two isolates were determined. Phylogenetic analysis showed the eight genes of the two isolates were closely related to those of the avian-like H1N1 viruses circulating in pig populations, especially similar to those found in China. Four potential glycosylation sites were observed at positions 13, 26, 198, 277 in the HA1 proteins of the two isolates. Due to the presence of a stop codon at codon 12, the isolates contained truncated PB1-F2 proteins. In this study, the isolates contained 591Q, 627E and 701N in the polymerase subunit PB2, which had been shown to be determinants of virulence and host adaptation. The isolates also had a D rather than E at position 92 of the NS1, a marker of mammalian adaptation. Both isolates contained the GPKV motif at the PDZ ligand domain of the 3′ end of the NS1, a characteristic marker of the European avian-like swine viruses since about 1999, which is distinct from those of avian, human and classical swine viruses. The M2 proteins of the isolates have the mutation (S31N), a characteristic marker of the European avian-like swine viruses since about 1987, which may confer resistance to amantadine and rimantadine antivirals. Our findings further emphasize the importance of surveillance on the genetic diversity of influenza A viruses in pigs, and raise more concerns about the occurrence of cross-species transmission events.


Influenza A virus Avian-like H1N1 Swine Molecular characterization 


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Copyright information

© Wuhan Institute of Virology, CAS and Springer-Verlag Berlin Heidelberg 2012

Authors and Affiliations

  • Xian Qi
    • 1
  • Yuning Pan
    • 2
  • Yuanfang Qin
    • 1
  • Rongqiang Zu
    • 1
  • Fengyang Tang
    • 1
  • Minghao Zhou
    • 1
  • Hua Wang
    • 1
    Email author
  • Yongchun Song
    • 2
  1. 1.Jiangsu Provincial Center for Disease Prevention and ControlNanjingChina
  2. 2.School of Life SciencesNanjing UniversityNanjingChina

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