CHARACTERIZATION OF HUMAN ROTAVIRUS GENOTYPE P[8]G5 FROM BRAZIL BY PROBE-HYBRIDIZATION AND SEQUENCE

We report the molecular characterization of rotavirus genotype P[8]G5 strains found in fecal specimens collected in four different regions o f Brazil, using digoxigenin (dig)-labeled oligonucleotide probes, sequ ence analysis, and RNA-RNA hybridization. The closest sequence relatio nships of the neutralization antigens of these strains were to the VP4 protein of P1A[8]G1 strain KU (93.3% identity in amino acids 11 to 28 2) and to the VP7 protein of G serotype 5 strain OSU (87.6% identity i n amino acids 8 to 232). Based on VP7 sequence differences, we designe d dig-probes that allowed us to discriminate porcine OSU-like strains from G5 strains isolated from Brazilian infants. The genetic relations hips of two P[8]G5 isolates to other rotavirus genogroups were analyze d by RNA-RNA hybridization with [P-32]-GTP probes representative of se rotypes P1A[8]G1 (Wa), P[8]G3 (AU17), and P9[7]G5 (OSU). The Brazilian P[8]G5 strains showed sequence homology with genes of Wa-like and OSU -like strains, suggesting that these two strains were naturally occurr ing reassortants between members of the Wa and porcine rotavirus genog roups. The identification of these strains in diverse geographic areas of Brazil underscores their stability and demonstrates the emergence of clinically important rotavirus diarrhea strains by reassortment.