Group A human rotaviruses (HuRVA) are causative agents of acute gastroenteritis. Six viral structural proteins (VPs) and six nonstructural proteins (NSPs) are produced in RV-infected cells. NSP4 is a diarrhoea-inducing viral enterotoxin and NSP4 gene analysis revealed at least 15 (E1-E15) genotypes. This study analysed the NSP4 genetic diversity of HuRVA G2P[4] strains collected in the state of São Paulo (SP) from 1994 and 2006-2010 using reverse transcription-polymerase chain reaction, sequencing and phylogenetic analysis. Forty (97.6%) G2P[4] strains displayed genotype E2; one strain (2.4%) displayed genotype E1. These results are consistent with the proposed linkage between VP4/VP7 (G2P[4]) and the NSP4 (E2) genotype of HuRVA. NSP4 phylogenetic analysis showed distinct clusters, with grouping of most strains by their genotype and collection year, and most strains from SP were clustered together with strains from other Brazilian states. A deduced amino acid sequence alignment for E2 showed many variations in the C-terminal region, including the VP4-binding domain. Considering the ability of NSP4 to generate host immunity, monitoring NSP4 variations, along with those in the VP4 or VP7 protein, is important for evaluating the circulation and pathogenesis of RV. Finally, the presence of one G2P[4]E1 strain reinforces the idea that new genotype combinations emerge through reassortment and independent segregation.

In this study, 331 samples from calves less than one month old from a dairy herd in the district of Piracanjuba, state of Goiás, Brazil were tested for rotavirus. Thirty-three samples (9.9%) tested positive for rotavirus. Out of those, 31 were submitted to G and P characterization by reverse transcription followed by semi-nested polymerase chain reaction. Two samples were characterized as G6P[1], three as G10P[11] and five as G6P[11]. The majority of the samples (51.6%) displayed multiple P genotypes (P-genotype mixtures), including typical human genotypes P[4] and P[6M], suggesting the occurrence of co-infections and genetic reassortment. Also, the detection of human genotypes in bovine samples may be considered evidence of the zoonotic potential of rotaviruses. To our knowledge, this is the first report of such a high frequency of P genotype mixtures in bovine rotavirus samples. It also increases data on G and P rotavirus genotypes circulating in dairy herds in Brazil and can help in the development of more efficient immunization approaches, thereby controlling infection and reducing economical losses.

The purpose of this study was to characterize astrovirus in faecal samples collected from children with and without diarrhea in São Paulo, Brazil, grouped into two sets: EPM and HU. Detection and genotyping were carried out using reverse transcription nested polymerase chain reaction (RT-PCR) with specific primers directed towards the genome open reading frame 2 (ORF2). Results for EPM set showed that 66/234 (28.2%) were positive: 28/94 (29.7%) from children with acute diarrhea, 14/45 (31.1%) with persistent diarrhea, and 9/55 (16.3%) from control individuals. No data was available for 15/40 (37.5%) of samples. Mixed infections with other viruses were found in 33 samples. In the HU, 18/187 (9.6%) were positive: 12/158 (7.6%) from individuals with acute diarrhea and 6/29 (20.7%) from control children. Four samples were mixed with other viruses. Out of 66 astrovirus positive EPM samples, 18 (27.2%) were characterized as human astrovirus type-1 (HAstV-1), two (3.0%) as HAstV-2, two (3.0%) as HAstV-3, and three (4.5%) as HAstV-8. Among 18 astrovirus positive HU samples, one (5.5%) was characterized as HAstV-1, six (33.3%) as HAstV-2, and one (5.5%) as HAstV-8. Two HAstV-8 genotyped samples were further confirmed by nucleotide sequencing. Our results shows that astroviruses are circulating in a constant manner in the population, with multiple serotypes, in higher frequency than it was described for other Brazilian regions. For the first time in Sao Paulo, Brazil, it was shown that astroviruses play an important role in children gastroenteritis, as described for most locations where they were detected.

De um total de 187 amostras fecais de crianças com idades entre 0 e 5 anos, coletadas no Hospital Universitário -USP, Brasil, de 1994 a 1996, 54 (28.9%) foram positivas para rotavírus. As amostras positivas foram caracterizadas quanto ao eletroferótipo, subgrupo, sorotipo G e genotipo G e P. Foram identificados quatro diferentes eletroferótipo longos em 38.9% das amostras, um eletroferótipo curto (34,0%) e 18,0% foram caracterizadas como um eletroferótipo não usual. O subgrupo I foi encontrado em 38,9% amostras, o subgrupo II em 50,0% e nãoI-nãoII em 7,7%. O sorotipo G2 foi encontrado em 59,3% e G1 em 33,3%. Duas amostras apresentaram misturas de G1+G2 e outra amostra G1+G3. Dez amostras caracterizadas como sorotipo G2 mostraram perfil eletroferótico longo. O genotipo G2 foi o mais freqüente, encontrado em 37 amostras (23 como único genotipo e 14 associados a outro genotipo). G1 foi encontrado em 15 amostras; G3 e G4 foram detectados principalmente em misturas e G5, G6 e G9, identificados somente em misturas. Um total de 20 (38,5%) amostras foram identificadas como misturas de genotipo G e foram encontradas 16 (29,6%) amostras com misturas de genotipo P. P[4] foi encontrado em 55,6% das amostras, P[8] em 51,9% e P[6-M37 like], em 5,5% das amostras. P[6-Gottfried like] e P[11] foram detectados somente em misturas. Uma amostra com especificidade G6, associada ao genotipo G2 e outra P[11] misturada com P[4] e de P[8] foram identificadas pela primeira vez na América Latina.

From a total of 187 fecal samples from children with ages between 0 and 5 years, collected in the Hospital Universitário -USP, Brazil, from 1994 to 1996, 54 (28.9%) were positive for rotavirus. Positive samples were characterized by electropherotyping, subgrouping, G serotype and genotype and P genotype. Rotavirus electropherotypes were characterized in four different long genome patterns (38.9%), one short genome pattern (34.0%) and 18.0% were characterized as an unusual pattern. Subgroup I was found in 38.9% strains, subgroup II in 50.0% and 7.7% was subgroup nonI-nonII. For G serotypes, G2 was found in 59.3%, G1 was identified in 33.3% of strains, two samples showed mixtures of G1+G2 and one sample was G1+G3. Ten samples characterized as serotype G2 showed a long eletropherotype. Genotype G2 was the most frequently and was found in 37 (44.0%) samples (23 samples as a single genotype and 14 as mixtures of genotypes). G1 was found in 15 samples. G3 and G4 was detected mainly in mixtures of genotypes and G5, G6 and G9 were identified only in mixtures. A total of 20 (38.5%) samples were characterized as G genotype mixtures and P mixtures were found in 16 (29.6%) samples. P[4] was found in 55.6% of samples, P[8] in 51.9% and P[6-M37 like] in 22.3% of cases. P[6-Gottfried like] and P[11] were detected only in mixtures. One sample with G6 specificity, mixed with a G2 rotavirus and a P[11] strain, mixed with P[4] and P[8]strain was described for the first time in Latin America.

Dez amostras fecais de rotavírus de bovinos de menos de 30 dias de idade, provenientes de um surto de diarréia no município de Hidrolândia, Goiás, Brasil foram submetidas à caracterização sorológica e molecular. Nove amostras foram caracterizadas como grupo A/subgrupo I e uma amostra foi grupo A/ subgrupo não-I/não-II. Quatro amostras foram caracterizadas como G10P[11] (B-223-like), quatro apresentaram mistura de rotavirus (G6G10 e P[5]P[11]), uma amostra foi caracterizada como G6P[11] e uma amostra foi caracterizada apenas como G10, não sendo caracterizada para genotipo P. Foram detectados dois eletroferótipos diferentes, ambos presentes no mesmo animal. Este estudo demonstra que em surtos de diarréia, podem estar presentes dois eletroferótipos e/ou sorotipos/genotipos de rotavírus de bovinos.

Ten faecal samples of bovine rotavirus from calves less than 30 days old from an outbreak of diarrhea in Hidrolândia, Goiás, Brazil were submitted to serological and molecular characterization, using enzyme immunoassay for subgrouping and serotyping, PAGE for determination of electropherotypes and PCR for genome typing. Nine samples belonged to group A/subgroup I rotavirus and one sample was group A / subgroup non-I/non-II. Four samples were characterized as G10P[11] (B223-like), four samples showed a mixture of two rotavirus strains (G6G10 and P[5]P[11]), one sample was characterized as G6P[11] and one sample was characterized only by G serotyping/genotyping, and did not react with any P primer used. Two electropherotypes were detected and both were present in the same animal. This study demonstrates that two different electropherotypes and/or serotypes of bovine rotavirus can circulate in the same outbreak.