Sun H.,Key Laboratory of Animal Disease Control and Prevention |
Sun H.,South China Agricultural University |
Jiao P.,Key Laboratory of Animal Disease Control and Prevention |
Jiao P.,South China Agricultural University |
And 12 more authors.
Journal of Animal and Veterinary Advances | Year: 2011
H5N1 Highly Pathogenic Avian Influenza (HPAI) viruses have posed a serious threat to poultry, wild birds and mammals including humans since 1997. Quails are a potential reservoir in which influenza viruses might mutate to a mammalian transmissible form. To investigate the molecular changes that occur in H5N1 HPAI viruses following passage in quail, two isolates, A/Quail/Guangdong/3 42/2008 (QL342) and A/Qquail/Guangdong/176/2004 (QL176) were selected. QL342 (clade 2.3.2)and QL176 (clade 7) viruses were high pathogenic to quail with a mortality rate of 18.3-100% and could be transmitted between naive contact quails. After six passages in Japanese quails, researchers obtained two viruses, F6QL342 and F6QL176. Compared with QL342, F6QL342 had six animo acid substitutions in polymerases PB1 and PA, Nucleoprotein (NP) and Hemagglutinin (HA) but there was little difference in their pathogenicity to mice. Compared with QL176, F6QL176 virus had 10 amino acid substitutions inPB2, NA, HA proteins. F6QL176 showed an increased pathogenicity towards mice causing more severe weight loss and higher lethality compared with QL176. The findings showed that quails might play an important role in the adaptation of H5N1 avian influenza viruses to mammals. Therefore, researchers should enhance surveillance of H5N1 HPAI viruses in the quail population especially in live-bird markets. © Medwell Journals, 2011.