Both social and engineering factors must be further explored and scrutinized across the globe—as should notions of justice related to flooding impacts and responses.
Image courtesy of Shutterstock.com/Ekaterina Pokrovsky.
New Research In
Physical Sciences
Featured Portals
Articles by Topic
Biological Sciences
Featured Portals
Articles by Topic
Contributed by Robert G. Webster, April 11, 2012 (sent for review November 4, 2011)
Abstract
Efficient worldwide swine surveillance for influenza A viruses is urgently needed; the emergence of a novel reassortant pandemic H1N1 (pH1N1) virus in 2009 demonstrated that swine can be the direct source of pandemic influenza and that the pandemic potential of viruses prevalent in swine populations must be monitored. We used the ferret model to assess the pathogenicity and transmissibility of predominant Korean triple-reassortant swine (TRSw) H1N2 and H3N2 influenza viruses genetically related to North American strains. Although most of the TRSw viruses were moderately pathogenic, one [A/Swine/Korea/1204/2009; Sw/1204 (H1N2)] was virulent in ferrets, causing death within 10 d of inoculation, and was efficiently transmitted to naive contact ferrets via respiratory droplets. Although molecular analysis did not reveal known virulence markers, the Sw/1204 virus acquired mutations in hemagglutinin (HA) (Asp-225-Gly) and neuraminidase (NA) (Ser-315-Asn) proteins during the single ferret passage. The contact-Sw/1204 virus became more virulent in mice, replicated efficiently in vitro, extensively infected human lung tissues ex vivo, and maintained its ability to replicate and transmit in swine. Reverse-genetics studies further indicated that the HA225G and NA315N substitutions contributed substantially in altering virulence and transmissibility. These findings support the continuing threat of some field TRSw viruses to human and animal health, reviving concerns on the capacity of pigs to create future pandemic viruses. Apart from warranting continued and enhanced global surveillance, this study also provides evidence on the emerging roles of HA225G and NA315N as potential virulence markers in mammals.
Footnotes
↵1P.N.Q.P. and M.-S.S. contributed equally to this work.
- ↵2To whom correspondence may be addressed. E-mail: robert.webster{at}stjude.org or choiki55{at}chungbuk.ac.kr.
Author contributions: P.N.Q.P., M.-S.S., and Y.K.C. designed research; P.N.Q.P., M.-S.S., J.H.L., Y.H.B., H.-i.K., S.-J.P., E.H.C., G.-J.L., O.-J.L., S.-W.K., M.H.S., M.H.K., S.-W.Y., and E.A.G. performed research; C.-J.K., E.A.G., R.G.W., and Y.K.C. contributed new reagents/analytic tools; P.N.Q.P., M.-S.S., M.H.K., S.-W.Y., E.A.G., R.J.W., R.G.W., and Y.K.C. analyzed data; and P.N.Q.P., M.-S.S., E.A.G., R.J.W., R.G.W., and Y.K.C. wrote the paper.
The authors declare no conflict of interest.
This article contains supporting information online at www.pnas.org/lookup/suppl/doi:10.1073/pnas.1205576109/-/DCSupplemental.
Virulent TRSw H1N2 influenza virus in ferrets
More Articles of This Classification
Biological Sciences
Microbiology
Related Content
Cited by...
- A North American H7N3 Influenza Virus Supports Reassortment with 2009 Pandemic H1N1 and Induces Disease in Mice without Prior Adaptation
- Molecular requirements for a pandemic influenza virus: An acid-stable hemagglutinin protein
- Prevalence, genetics, and transmissibility in ferrets of Eurasian avian-like H1N1 swine influenza viruses
- Influenza A Virus Acquires Enhanced Pathogenicity and Transmissibility after Serial Passages in Swine
- Expansion of Genotypic Diversity and Establishment of 2009 H1N1 Pandemic-Origin Internal Genes in Pigs in China
- The Homologous Tripartite Viral RNA Polymerase of A/Swine/Korea/CT1204/2009(H1N2) Influenza Virus Synergistically Drives Efficient Replication and Promotes Respiratory Droplet Transmission in Ferrets
Similar Articles
You May Also be Interested in
Blair Hedges discusses the state of Haiti's remaining forests and the consequences to biodiversity.
A study uncovers genetic evidence of early colonization of Jamaica by primates and suggests that adaptation can shape species morphology in novel environments, even when species come from morphologically conservative families.
Image courtesy of Lorraine Meeker (American Museum of Natural History, New York).
Researchers report that some moth species use sound absorbing-scales to avoid detection by bats and suggest that the findings could aid the design of biologically inspired sound absorbers for an array of applications, including noise mitigation and building acoustics.
Image courtesy of Thomas R. Neil.
Using phylogenetic analysis, researchers report that ants used plants for food and nesting long before plants evolved structures to accommodate arthropods, and although interactions with ants likely facilitated plant diversification, plant interactions did not shape ant diversification.
Image courtesy of Pixabay/cmolens.
