Phylogenetic analyses of Norovirus strains detected in Uruguay reveal the circulation of the novel GII.P7/GII.6 recombinant variant

Noroviruses (NoV) are one of the major etiological agent of acute gastroenteritis (AGE) outbreaks worldwide. Distinct NoV genotypes have been associated with different transmission patterns and disease severity in humans. Therefore, it is important to identify genetically different NoV genotypes circulating in a particular region. However, genotyping has become a challenge due to recombination events occurring mainly nearby ORF1/ORF2 junction of NoV genome, leading to distinct genotypes with polymerase and capsid regions derived from parenteral strains. Taking this into account, ORF1/ORF2 sequences were obtained from NoV strains collected from patients with AGE in Uruguay. This study reveals in silico evidences of recombination events taking place in four out of six strains analyzed for which its polymerase gene and its capsid region correspond to GII.P7 and to GII.6 genotype, respectively. These results also reveal the circulation of a GII.P7/GII.6 recombinant variant in the natural populations of NoV strains in the northwestern region of Uruguay. As far as we know this is the first report about the circulation of a NoV GII.P7/GII.6 recombinant variant in the Americas.