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ARS Home » Midwest Area » Ames, Iowa » National Animal Disease Center » Virus and Prion Research » Research » Publications at this Location » Publication #312887
Title: Replication and transmission of mammalian-adapted H9 subtype influenza virus in pigs and quail

Author
item OBADAN, ADEBIMPE - Virginia-Maryland Regional College Of Veterinary Medicine (VMRCVM)
item KIMBLE, BRIAN - Virginia-Maryland Regional College Of Veterinary Medicine (VMRCVM)
item RAJAO, DANIELA - Non ARS Employee
item Lager, Kelly
item SANTOS, JESSERSON - Virginia-Maryland Regional College Of Veterinary Medicine (VMRCVM)
item Baker, Amy
item PEREZ, DANIEL - Virginia-Maryland Regional College Of Veterinary Medicine (VMRCVM)

Submitted to: Journal of General Virology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/18/2015
Publication Date: 9/1/2015
Citation: Obadan, A.O., Kimble, B.J., Rajao, D., Lager, K.M., Santos, J.J., Vincent, A.L., Perez, D.R. 2015. Replication and transmission of mammalian-adapted H9 subtype influenza virus in pigs and quail. Journal of General Virology. 96:2511-2521.

Interpretive Summary: Influenza A virus is a major pathogen of birds, swine, and humans. Strains can jump from one species to another in a process that often requires genetic changes, events that may result in outbreaks and, potentially, human pandemics. H9N2 avian influenza is one of the most predominant influenza subtypes in poultry across much of Asia. H9N2 viruses have occasionally infected humans and swine. Pandemic H1N1 (H1N1pdm) is endemic in humans and swine, therefore providing opportunity for mixed infections with H9N2 and reassortment of the two sets of virus genes. Previous studies have shown the compatibility of H9N2 and H1N1pdm reassorted viruses in ferrets, a model for human infection and transmission, and that these viruses were more efficient after a series of infections in ferrets (adaptation). Here, the effects of ferret adaptation on the infectivity and transmission of H9 viruses in at-risk natural hosts, swine and quail, was analyzed. These results highlight that ferret-adapted mutations on the HA of H9 subtype virus do not restrict the virus ability to infect swine or quail and the viruses with H1N1pdm genes were more infectious in swine. As such, this study emphasizes the threat that H9N2 reassortant viruses pose to humans and important agricultural species, and the role swine and quail could play in the generation of novel H9 viruses.

Technical Abstract: Influenza A is a major pathogen of birds, swine, and humans. Strains can jump from one species to another in a process that often requires genetic mutation and genome reassortment and results in outbreaks and, potentially, pandemics. H9N2 avian influenza is one of the most predominant influenza subtypes in poultry across much of Asia. H9N2 viruses have occasionally infected humans and swine. Pandemic H1N1 (H1N1pdm) is endemic in humans and swine and has a history of reassortment in pigs. Previous studies have shown the compatibility of H9N2 and H1N1pdm for reassortment in ferrets, a model for human infection and transmission. Here, the effects of ferret adaptation of H9 subtype surface gene segments on the infectivity and transmission in at-risk natural hosts, specifically swine and quail, is analyzed. Reassortant H9N1 and H9N2 viruses, carrying 7 or 6 gene segments from the H1N1pdm strain showed infectivity and transmissibility in swine, unlike the whole avian H9N2 virus with ferret-adapted surface genes. In quail, only the reassortant H9N2 with the 6 internal gene segments from the H1N1pdm strain was able to infect and transmit, however, with less efficiency than the whole avian H9N2 virus with ferret-adapted surface genes. These results highlight that ferret-adapted mutations on the HA of H9 subtype virus do not restrict the virus ability to infect swine or quail and maintains the ability to transmit in both of these species depending on the context of the whole virus. As such, this study emphasizes the threat that H9N2 reassortant viruses pose to humans and important agricultural species, and the role swine and quail could play in the generation of novel viruses as possible mixing vessel species.