Abstract
Swine influenza virus causes a substantial disease burden to swine populations worldwide and poses an imminent threat to the swine industry and humans. Given its importance, we characterized two swine influenza viruses isolated from Shandong, China. The homology and phylogenetic analyses showed that all eight gene segments of A/swine/Shandong/AV1522/2011(H1N1) were closely related to A/Maryland/12/1991(H1N1) circulating in North America. The HA, NA, M, and NS genes of the isolate were also confirmed to have a high homology to A/swine/Hubei/02/2008(H1N1) which appeared in China in 2008, and the virus was clustered into the classical swine lineage. The gene segments of A/swine/Shandong/AV1523/2011(H1N1) were highly homologous to the early human H1N1 and H2N2 influenza viruses, except for the HA gene, and the virus was a reassortant H1N1 virus containing genes from the classical swine (HA) and human (NA, PB2, PB1, PA, NP, M, and NS) lineages. Both the viruses could cause lethal infection and replicate efficiently in the lungs, brains, spleens, and kidneys of mice. Histopathological examinations showed that AV1522 and AV1523 viruses caused a spectrum of marked pneumonia and meningoencephalitis according to the duration of infection, demonstrating a progression of respiratory disease and neurological disease over the course of infection that ultimately resulted in lethality for the infected mice. The changes in the pathogenicity of swine influenza viruses to mammals, accompanied with the continuous reassortment and evolution of the viruses, highlights the importance of ongoing epidemiological investigation.
Highlights
Swine influenza virus (SIV) is a highly contagious viral infection of pigs that can cause significant economic impact on animal husbandry and poses a potential pandemic threat to humans
The virus was isolated in 1930, which is known as classical swine H1N1 influenza virus (CS H1N1 virus) [30,31]
This CS H1N1 virus continued to circulate as the dominant influenza virus in the North
Summary
Swine influenza virus (SIV) is a highly contagious viral infection of pigs that can cause significant economic impact on animal husbandry and poses a potential pandemic threat to humans. There are currently 18 HA subtypes and 11 NA subtypes, most of which circulate in wild birds [2], and classical and avian H1N1, human. H1N1 and H1N2, reassortant H3N2 (r), and rH1N2 are known to have circulated widely in pigs. RH1N7, rH2N3, rH3N1, equine H3N8, H5N2, H6N6, H7N2, H4N8, H11N6, avian avH3N3, Viruses 2020, 12, 55; doi:10.3390/v12010055 www.mdpi.com/journal/viruses avH4N6, avH5N1, and avH9N2, have been occasionally identified in pigs in different parts of the world [3,4,5,6,7,8,9,10]. Gradual changes of the antigenic properties are known as antigenic drift
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
