Predominance of DS‐1‐like G8P[8] rotavirus reassortant strains in children hospitalized with acute gastroenteritis in Thailand, 2018–2020

Abstract

AbstractRotavirus A (RVA) is an important cause of acute gastroenteritis (AGE) in children. This study aims to investigate the molecular epidemiology of RVA in children hospitalized with AGE in Chiang Rai, Thailand in 2018–2020 by reverse transcription polymerase chain reaction. Of 302 samples, RVA was detected in 11.6% (35 samples): 11.3% (19/168) in 2018–2019 and 11.9% (16/134) in 2019–2020. G8P[8] was the predominant genotype at 68.4% in 2018–2019 and 81.2% in 2019–2020. G1P[8] (15.8%), G2P[4] (5.3%), G3P[8] (10.5%) in 2018–2019, and G9P[8] (18.8%) in 2019–2020 were also detected. Whole‐genome analysis of G8P[8] revealed a DS‐1‐like genetic backbone: G8‐P[8]‐I2‐R2‐C2‐M2‐A2‐N2‐T2‐E2‐H2. Phylogenetically, the VP7 genes of G8P[8] clustered in a major lineage with previously published 51 DS‐1‐like G8P[8] reference strains, closely related to 13 G8P[8] strains from Thailand and China. These G8P[8] strains contained two unique amino acid substitutions (A125S and N147D) in the VP7 antigenic epitopes. In addition, the VP1 and NSP2 genes of G8P[8] clustered in lineages separated from the DS‐1‐like G8P[8] reference strains with a high genetic divergence but were closely related to G1P[8], G2P[4], G3P[8], or G9P[8]. Several amino acid differences were observed in the VP7 and VP8* antigenic epitopes of G8P[8] compared with RVA vaccine strains. Homology modeling confirmed that these different amino acid residues were located on the surface‐exposed area of the structure. Taken together, the genetic analysis clearly defines the Chiang Rai DS‐1‐like G8P[8] strains as a novel reassortant strain that might have evolved genetically through reassortment events and consequently received their VP1 and NSP2 genes from locally cocirculating‐RVA genotypes.