Rotavirus B (RVB) has been identified as a causative agent of diarrhea in rats, humans, cattle, lambs, and swine. Recently, 20 RVB VP7 genotypes were determined based on an 80% nucleotide percent cut-off value. In this study, we sequenced the RVB VP6 gene segment from 80 RVB positive swine samples from the United States and Japan. Phylogenetic analyses, using the 30 available RVB VP6 sequences from GenBank and our 80 novel RVB VP6 sequences, revealed a large genetic diversity of RVB strains, mainly in pigs. For classification purposes, pairwise identity frequency analyses suggested an 81% nucleotide percent cut-off value, resulting in 13 RVB VP6 (I) genotypes. In addition, an intragenic recombinant RVB VP6 segment was identified from Japan. Furthermore, the data indicates frequent reassortment events occurred between the porcine RVB VP7 and VP6 gene segments.
Bibliographical noteFunding Information:
The Japanese RVB sequencing was funded in part by a grant-in-aid for scientific research from the Ministry of Health, Labor and Welfare of Japan and by a grant from the National Institute of Animal Health, National Agriculture and Food Research Organization , Japan. The USA RVB sequencing and phylogenetic analysis was funded by the University of Minnesota Veterinary Diagnostic Laboratory .
- Genetic diversity
- Intragenic recombination
- Porcine enteric pathogen
- Rotavirus B