Intergenogroup recombinant sapovirus in Japan, 2007-2008.
Bottom Line: We investigated the incidence of sapovirus (SaV)-associated gastroenteritis in infants and children in Japan during 2007-2008 and characterized the diversity of SaV-positive strains.SaV was detected in 19 (4%) of 477 fecal specimens.The leading genogroup (79%, 15 cases) comprised intergenogroup recombinant SaVs (GII/GIV).
Affiliation: The University of Tokyo, Tokyo, Japan.
We investigated the incidence of sapovirus (SaV)-associated gastroenteritis in infants and children in Japan during 2007-2008 and characterized the diversity of SaV-positive strains. SaV was detected in 19 (4%) of 477 fecal specimens. The leading genogroup (79%, 15 cases) comprised intergenogroup recombinant SaVs (GII/GIV).
Related in: MedlinePlus
Mentions: Nucleotide sequence comparison of the identified 15 GIV shared little or almost no divergence among themselves (98%–100% identity), even when they were detected in regions of Japan distant from each other. They are likely to represent a single strain, 8208/Maizuru/08/JP. The 8208/Maizuru/08/JP sequence closely matched Ehime1107 and SW278 (5), and Yak2 (6) sequences, which were previously established as intergenogroup recombinant SaV strains with the GII polymerase region and GIV capsid region, with 97% and 96% nucleotide identities, respectively. To determine whether our GIV strains were the recombinant SaV, 5 of the 15 GIV strains were randomly selected as representative, and long genomic fragments that included part of the RNA polymerase and part of the capsid genes were amplified by using primers SR80/2 (5′-TGGGATTCTACACAAAACCC-3′) and SLV5749 (5′-CGGRCYTCAAA VSTACCBCCCCA-3′), which generated a 1,151-bp product. The products were directly sequenced, and capsid- and polymerase-based phylogenetic trees confirmed these strains as the recombinant SaVs (Figure 2). We suggest the GIV strains isolated in our study were intergenogroup recombinants. Also, these recombinant strains were detected in 4 locations distant from each other: Maizuru city (10 cases), Sapporo and Saga (2 cases each), and Osaka (1 case), which suggests that the recombinant strains were widely spread through the country.