Detection of a neonatal human rotavirus strain with VP4 and NSP4 genes of porcine origin.

A human rotavirus strain (NB-150) was detected in stool samples from a neonate hospitalized for mild/moderate community-acquired diarrhoea. This baby lived in the outskirts of Belém, Brazil, under poor sanitation conditions. The NB-150 strain displayed a typical long electrophoretic pattern with 11 gene segments. It had two VP7 alleles, G1 and G4, and belonged to VP6 subgroup II. A close relatedness with human rotaviruses was shown for VP7 alleles: G1 (96.9-100 % similarity at the amino acid level) and G4 (97.1-100 % similarity at the amino acid level). As for VP6, 95.1-97.5 % similarity at the amino acid level was noted. VP8* and NSP4 genes showed a close relatedness with those of porcine rotavirus strains, as follows: VP8* (95.0 % similarity at the amino acid level) and NSP4 (93.7-96.0 % similarity at the amino acid level). This is believed to be the first report in Brazil of a rotavirus infection involving a strain with G1 and G4 alleles, with VP8* and NSP4 genes of porcine origin. These findings strongly suggest the occurrence of interspecies transmission.