We report the full-length sequence of two chicken source influenza A (H7N9) viruses found in Guangdong live poultry market (LPM) during the most recent wave of human infections (from October 2016 to the present time). These viruses carry insertion of poly-basic amino acids (KGKRTAR/G) at the protease cleavage site of the HA protein, which were previously found in the highly pathogenic (HP) human influenza A (H7N9) [IAV(H7N9)] strains. Phylogenetic analysis of these two novel avian influenza viruses (AIVs) suggested that their genomes reassorted between the Yangtze River Delta (YRD) and Pearl River Delta (PRD) clades. Molecular clock analysis indicated that they emerged several months before the HP human strains. Collectively, our results suggest that IAV(H7N9) viruses evolve in chickens through antigenic drift to include a signature HP sequence in the HA gene, which highlights challenges in risk assessment and public health management of IAV(H7N9) infections at the human-animal interface.
|Original language||English (US)|
|State||Published - Dec 1 2017|
Bibliographical noteFunding Information:
We acknowledge those who contributed to the generation of the genome sequences of influenza A (H7N9) viruses in GISAID, for which this research is based (Table S3). This study was supported in parts by the High-Level Talent Start-Up Research Project of the Foshan University (Gg040967); Educational Department of Guangdong Province, China (2014KZDXM062); Scientific and Technological Innovation Program of Foshan (2014AG10022); Agriculture Department of Guangdong Province, China (NO.1046); National Natural Science Foundation of China (31400150) and Natural Science Foundation of Guangdong Province, China (2015A030313473, 611083989110).
© 2017 The Author(s).