Co-infection in chickens with H7N9 and H9N2 viruses

This study aims to investigate the reassortment patterns of a Pearl River Delta-lineage avian influenza A(H7N9) virus and four genetically divergent avian influenza A(H9N2) viruses upon co-infection in chickens. The H7N9 virus is A/silkie Chicken/Hong Kong/1772/2014(H7N9) (designated as HK1772); and four H9N2 viruses are A/quail/Hong Kong/G1/1997 (designated as G1), A/silkie chicken/Hong Kong/YU335/2007 (designated as YU335), A/chicken/Zhejiang/HJ/2007 (designated as HJ), and A/chicken/Beijing/16/2013(H9N2) (designated as BJ16), respectively. Three chickens were inoculated intranasally with a mixture of the H7N9 virus and one H9N2 virus (1000000 EID50 per virus). Oropharyngeal swabs collected at 3 dpi were analyzed by next generation sequencing.