Complex evolutionary patterns of two rare human G3P[9] rotavirus strains possessing a feline/canine-like H6 genotype on an AU-1-like genotype constellation

► Whole genomic analysis of two rare human G3P[9] rotavirus strains detected in China. ► Strains L621 and E2451 had a H6 NSP5 genotype on an AU-1-like genotpe constellation. ► Identification of different evolutionary patterns among AU-1-like strains. ► Nearly all the eleven genes of L621 and E2451 originated from feline/canine strains. ► Evidence for reassortments among feline/canine rotaviruses before transmission to humans.