Genetic characterization of a rare bovine-like human VP4 mono-reassortant G6P[8] rotavirus strain detected from an infant in Bangladesh

- During surveillance a rare G6P[8] RVA (KH2288) was detected from a 7 month old infant in Bangladesh.
- This is the first report of the complete genotype analysis of all 11 genes of a G6P[8] strain worldwide.
- Except VP4 (P[8]), the other 10 gene segments clustered with animal or animal-derived human RVAs.
- KH2288 was shown to be a mono-reassortant between a human and a bovine-like RVA strain.
- KH2288 shared 10 out of 11 genotypes with one of the RotaTeq reassortants, but was not vaccine derived.

During an ongoing diarrhea etiology surveillance in Mirzapur, Bangladesh, a rare human G6P[8] RVA strain (RVA/Human-wt/BGD/KH2288/2011/G6P[8]) was detected in a stool sample of a 7-month-old infant with acute diarrhea. Complete genotype analyses revealed that KH2288 possessed the G6-P[8]-I2-R2-C2-M2-A11-N2-T6-E2-H3 genotype constellation. Sequence analysis of the VP7 gene revealed a close phylogenetic relationship with bovine G6 strains from India, whereas, the VP4 gene segment was nearly identical to typical human P[8] strain circulating in Bangladesh and the rest of the world. Phylogenetic analysis of the remaining nine gene segments revealed a close relatedness to either animal or animal derived human RVA strain. We speculated that, strain KH2288 was a monoreassortant between a human RVA strain and a RVA strain typically infecting member of the Artiodactyla, such as cattle, goat or sheep. To our knowledge, this is the first complete genotyping report of a naturally occurring G6P[8] RVA strain, worldwide.