Amino acid #mutations K54E and S154P in the #neuraminidase attenuate #H3N2 #canine #influenza virus in mice
ABSTRACT Dogs are considered mixing vessels for influenza viruses , posing a pandemic potential via viral reassortment . Our previous studies indicated that the avian-origin H3N2 canine influenza virus (A/canine/Zhejiang/1/2010, abbreviated C1) is virulent in canine and mice . Furthermore, we found that the HA and NA genes of C1 share a close genetic relationship with an H3N2 avian influenza virus (A/duck/Shanghai/06/2009, abbreviated D6), but they exhibit distinct pathogenicity . However, the understanding mechanisms remain unclear. In the present study, we explored the genetic determinants that contribute to the different pathogenicity between the C1 and D6. By using the reverse genetics approaches, we rescued several single-gene and position-substituted reassortant viruses based on the C1. The replication in Madin–Darby canine kidney cells and pathogenic trial in mice showed that the neuraminidase (NA) gene played a critical role in C1 virulence. Further analysis demonstrated ...