Genomic characterization of GII.3 noroviruses isolated from children in Zhengzhou city, China, 2015/16.

In this study, we isolated, amplified and sequenced GII.3 norovirus (NoV) strains from children admitted to a department of pediatric gastroenterology presenting with acute gastroenteritis from September 2015 to March 2016. A total of 35 stool samples were collected and eight were GII.3 NoV positive, based on sequencing. The complete genome sequences were determined for two strains while partial genome sequences, encompassing approximately 3.2 kb of the 3´end, were generated for the six other strains. Genotyping analysis of all strains indicated that they belonged to GII P12/GII.3. Phylogenetic analysis indicated that these isolated strains could be divided into two clusters. Strains in cluster IV were the most frequently isolated and exhibited less intra-cluster variation in nucleotide sequences. Our study demonstrated that the GII.P12/GII.3 recombinant strain was the dominant GII.3 NoVs in Zhengzhou city.