Two Lineages of DS-1-Like G3P[8] Human Rotaviruses in Sabah, Malaysia: Genetic Diversity and Evidence of Reassortment.

Group A rotavirus (RVA) genotype G3P[8] strains typically carry a Wa-like genomic backbone, but DS-1-like G3P[8] reassortants have disseminated globally since 2013. In Sabah, Malaysia, surveillance in 2018-2019 identified frequent G3P[8] strains with a short RNA electropherotype, consistent with DS-1-like backbones. Here, we sequenced whole genomes (Illumina MiSeq) of seven representative short-pattern strains (KN4, KN7, L39, L68, L116, L222, and L286) and a co-circulating long-pattern Wa-like G3P[8] strain (L86). Six short-pattern strains possessed the canonical DS-1-like backbone I2-R2-C2-M2-A2-N2-T2-E2-H2, whereas one strain (L116) carried a Wa-like VP3 genotype (M1) within an otherwise DS-1-like genome. Whole-genome phylogenies segregated the DS-1-like strains into two lineages-KN4-like (with KN4, KN7, and L68) and L39-like (with L39, L116, L222, and L286)-that each represented different globally circulating DS-1-like G3P[8] clades, consistent with at least two distinct introductions into Sabah. L116 VP3 shared < 80% with the other study strains, whereas for the remaining segments this was > 93%. Instead, L116 VP3 clustered with Wa-like G12, suggesting a DS-1-like/Wa-like intergenogroup (within backbone) reassortment event. Our findings contribute to understanding the evolutionary dynamics of globally emerging DS-1-like G3P[8] strains.