Whole genomic analysis of human and bovine G8P[1] rotavirus strains isolated in Nigeria provides evidence for direct bovine-to-human interspecies transmission

• Whole genomic analysis of human and bovine G8P[1] strains isolated in Nigeria.
• Each of the 11 genes of both G8P[1] strains appeared to be of bovine origin.
• The two G8P[1] strains were very closely related to each other in all the 11 genes.
• The two G8P[1] strains appeared to be derived from a common origin.
• Strain NGRBg8 appeared to represent bovine strains that were transmitted to humans.
• Clear evidence of direct bovine-to-human interspecies transmission of RVA strains.

Bovine group A rotavirus (RVA) G8P[1] strains have been rarely detected in humans. Two Nigerian G8P[1] strains, HMG035 (RVA/Human-tc/NGA/HMG035/1999/G8P[1]) and NGRBg8 (RVA/Cow-tc/NGA/NGRBg8/1998/G8P[1]), were previously suggested to have the VP7, VP4, and NSP1 genes of bovine origin. In order to obtain precise information on the origin and evolution of these G8P[1] strains, the complete nucleotide sequences of the whole genomes of strains HMG035 and NGRBg8 were determined and analyzed in the present study. On whole genomic analysis, strains HMG035 and NGRBg8 were found to be very closely related to each other in all the 11 segments, and were found to have a bovine RVA-like genotype constellation (G8-P[1]-I2-R2-C2-M2-A11-N2-T6-E2-H3). Furthermore, on phylogenetic analysis, each of the 11 genes of strains HMG035 and NGRBg8 appeared to be of bovine origin. Thus, strains HMG035 and NGRBg8 were suggested to be derived from a common origin, and strain NGRBg8 was assumed to represent an example of bovine RVA strains that were transmitted to humans. Our findings provide clear evidence for direct bovine-to-human interspecies transmission of RVA strains.