Intergenotype Recombination among New Norovirus GII.4 Variants in the Complete Genome.

GII.4 noroviruses (NoVs) are a major cause of acute gastroenteritis in humans. A new variant of GII.4, the Sydney variant, has recently become more prevalent on a global scale. Intragenotype recombinations are widespread within the pandemic NoV GII.4 lineage, and are likely to be important forces driving the evolution and emergence of novel GII.4 viruses. In this study, we sought to examine the role that intergenotype recombination has played in the emergence of GII.4 Sydney 2012 variants. The results show that the GII.4 Sydney 2012 variants, Kawasaki194 and CA3477, were intergenotype recombination NoV strains with a GII.4 capsid and a GII.P16 polymerase gene. It has been reported for the first time that GII.4 new variant recombinants come from intergenotype recombination of GII.P16 and GII.4 strains in the complete genome.