Phylogeographic characteristics of reassortant DS-1-like G3P[8]-strains of rotavirus type A isolated in Nizhny Novgorod (Russia).

Abstract

Since 2013, there has been an increase in reports of the spread of a double intergroup reassortant strain of rotavirus type A (RVA) with the genotype G3P[8] and other genes belonging to the second genogroup I2-R2-C2-M2-A2-N2-T2-E2-H2. Our study found an increase in the proportion of G3P[8] with a short migration profile of genome segments in RNA-PAGE from 15% (2020-2021) to 53% (2021-2022) in Nizhny Novgorod (Russia). The VP7, VP4 and VP6 genes were sequenced by the Sanger method. It was found that the studied strains belong to the genotype G3P[8]-I2, and are reassortants between Wa- and DS-1-like rotaviruses. Phylogenetic analysis revealed that VP7 sequences of studied strains are closely related to DS-1-like G3P[8] RVA, which have been isolated in other countries. The RVAs isolated in Nizhny Novgorod carried the allele P[8]-3.1 of the VP4 gene, as well as other worldwide spreading G3P[8] DS-1-like reassortants. None of the VP6 sequences of studied G3P[8] RVA were included in the group with equine-like strains isolated in other countries. Most VP6 alleles of Nizhny Novgorod G3P[8] DS-1-like RVAs clustered with G2P[4], which were studied earlier. This fact may indicate a local reassortment of the spread strains.