Whole genomic analyses of equine group A rotaviruses from Japan: evidence for bovine-to-equine interspecies transmission and reassortment events.
Equine group A rotaviruses (RVA) are a major cause of severe diarrhea in foals. The whole genomes of only six common and three unusual equine RVA strains have been analyzed so far. To date, there are no reports on whole genomic analyses of equine RVAs from Asian countries. We report here the whole genomic analyses of three common (strains RVA/Horse-tc/JPN/BI/1981/G3P[12], RVA/Horse-tc/JPN/HH-22/1989/G3P[12] and RVA/Horse-tc/JPN/CH-3/1987/G14P[12]) and an unusual (RVA/Horse-tc/JPN/OH-4/1982/G6P[5]) equine RVA strains isolated from diarrheic foals in Japan. Strains BI, HH-22 and CH-3 shared a largely conserved genotype constellation (G3/G14-P[12]-I2/I6-R2-C2-M3-A10-N2-T3-E2-H7) with each other and with those of common equine RVAs from other continents. Phylogenetically, most of the genes of BI, HH-22 and CH-3 were closely related to those of other common equine RVAs. On the other hand, the NSP2 genes of BI and CH-3 formed a distinct lineage, and were distantly related to the other, major equine RVA cluster within the NSP2-N2 genotype. The NSP4 gene of HH-22 appeared to originate from possible reassortment events involving common equine RVAs and co-circulating bovine or bovine-like equine RVAs, revealing the presence of a bovine RVA-like NSP4 gene on a typical equine RVA genetic backbone. All the 11 gene segments of the unusual equine RVA strain OH-4 were found to be more closely related to those of bovine and bovine-like human RVAs than to those of other RVAs, providing the first conclusive evidence for artiodactyl(likely bovine)-to-equine interspecies transmission events. Taken together, these observations provided important insights into the genetic diversity of equine RVAs.
Department of Hygiene, Sapporo Medical University School of Medicine, Sapporo, Japan. souvikrota@gmail.com
Souvik
S
Ghosh
Koki
K
Taniguchi
Satoru
S
Aida
Balasubramanian
B
Ganesh
Nobumichi
N
Kobayashi
D000818:Animals; D001483:Base Sequence; D002417:Cattle; D002418:Cattle Diseases / Q000635:transmission / Q000821:virology*; D014644:Genetic Variation; D016679:Genome, Viral; D023281:Genomics; D005838:Genotype; D006734:Horse Diseases / Q000635:transmission / Q000821:virology*; D006736:Horses; D007564:Japan; D008969:Molecular Sequence Data; D010802:Phylogeny; D011995:Recombination, Genetic; D012401:Rotavirus / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D012400:Rotavirus Infections / Q000635:transmission / Q000662:veterinary* / Q000821:virology; D014764:Viral Proteins / Q000235:genetics
D014764:Viral Proteins
Asia; Bovine-to-equine interspecies transmission; Equine group A rotaviruses; Genetic reassortment; Whole genomic analyses