%0 Journal Article %A Kitikoon, Pravina %A Nelson, Martha I. %A Killian, Mary Lea %A Anderson, Tavis K. %A Koster, Leo %A Culhane, Marie R. %A Vincent, Amy L. %T Genotype patterns of contemporary reassorted H3N2 virus in US swine %D 2013 %J Journal of General Virology, %V 94 %N 6 %P 1236-1241 %@ 1465-2099 %R https://doi.org/10.1099/vir.0.051839-0 %I Microbiology Society, %X To understand the evolution of swine-origin H3N2v influenza viruses that have infected 320 humans in the USA since August 2011, we performed a phylogenetic analysis at a whole genome scale of North American swine influenza viruses (n  =  200). All viral isolates evolved from the prototypical North American H3 cluster 4 (c4), with evidence for further diversification into subclusters. At least ten distinct reassorted H3N2/pandemic H1N1 (rH3N2p) genotypes were identified in swine. Genotype 1 (G1) was most frequently detected in swine and all human H3N2v viruses clustered within a single G1 clade. These data suggest that the genetic requirements for transmission to humans may be restricted to a specific subset of swine viruses. Mutations at putative antigenic sites as well as reduced serological cross-reactivity among the H3 subclusters suggest antigenic drift of these contemporary viruses. %U https://www.microbiologyresearch.org/content/journal/jgv/10.1099/vir.0.051839-0