The circulation of human astrovirus genotypes in the Central West Region of Brazil.

Out of 1,588 faecal samples of children taken from three locations of the Central West Region of Brazil, 57 were positive for astroviruses (HAstVs) using reverse transcription-polymerase chain reaction (RT-PCR). They were genotyped by nested RT-PCR and/or genomic sequencing. HAstV-1 (42.8%), HAstV-2 (23.2%), HAstV-3 (3.6%), HAstV-4 (14.3%) and HAstVs -5, -6, -7 and -8 (1.8% each) were detected. In Goiânia and Campo Grande, HAstV-1 was the most frequently detected genotype while in Brasília (DF) it was HAstV-2. Shifts in the circulation of astrovirus genotypes were observed in DF and Campo Grande. All samples collected by rectal swabs were viral negative. The astrovirus genotypes were detected in all age groups and there was no correlation between genotype and age group.

Molecular characterization of VP6-encoding gene of group A human rotavirus samples from central west region of Brazil.

Group A rotaviruses are the main cause of acute gastroenteritis in children worldwide. The intermediate capsid protein VP6 encoded by segment 6 of the dsRNA genome is the major structural component of the virus and it is highly antigenic and immunogenic. VP6 is responsible for group and subgroup (SG) specificities, allowing classification of group A rotavirus into SG I, SG II, SG I + II, and SG non-I-non-II. VP6-encoding gene of 154 group A human rotavirus samples of different G and P genotypes recovered from children in three cities of Central West region of Brazil was amplified by reverse transcription-polymerase chain reaction followed by sequencing and phylogenetic analysis. Two distinct genetic groups could be recognized: VP6 genogroups I and II. Sequences analysis also revealed that all samples identified as VP6 genogroup I were associated with NSP4 genotype A, whereas samples identified as VP6 genogroup II were associated with NSP4 genotype B. This is the first study in Central West region regarding genetic variability of the VP6 gene. Further molecular surveillance of rotavirus strains is needed to understand better the occurrence of VP6 gene diversity in Brazil and the significance of VP6 for the control and prevention of rotavirus gastroenteritis.

Adenovirus, calicivirus and astrovirus detection in fecal samples of hospitalized children with acute gastroenteritis from Campo Grande, MS, Brazil.

We analyzed fecal samples from hospitalized children up to three years of age with acute gastroenteritis at Campo Grande, Mato Grosso do Sul, Brazil, from May 2000-January 2004. Astrovirus and calicivirus were detected by Reverse Transcription-Polymerase Chain Reaction and adenovirus was detected using the Rotavirus and Adenovirus combined immunoenzyme assay. Astrovirus, adenovirus and calicivirus were detected at rates of 3.1%, 3.6% and 7.6%, respectively. These results re-emphasize the need for the establishment of regional vigilance systems to evaluate the impact of enteric viruses on viral gastroenteritis.

[Rotavirus A among hospitalized infants, up to three years of age, with acute gastroenteritis in Campo Grande, State of Mato Grosso do Sul]. / Rotavírus A em crianças de até três anos de idade, hospitalizadas com gastroenterite aguda em Campo Grande, Estado do Mato Grosso do Sul.

Polyacrylamide gel electrophoresis and combined immunoenzyme assay for rotavirus and adenovirus were used to analyze 380 fecal samples from children up to three years of age who were hospitalized with acute diarrhea in Campo Grande, State of Mato Grosso do Sul, between May 2000 and January 2004. Among all the samples, 88 (23.2%) were positive for Rotavirus A. Out of these, 81 (92%) had a defined electrophoretic pattern: 77 (87.5%) with a long pattern and four (4.5%) with a short pattern. Genotype G and P characterization was done by nested RT-PCR for 85 samples, of which 56 (65.9%) were genotyped as type G. Among these, 49 (87.5%) were G1, five (8.9%) were G4, one (1.8%) was G3 and one (1.8%) was G9. The genotype was found to be type P in 37 samples (43.5%) and all of these were P[8]. The G and P association most observed was G1P[8], with 33 samples (89.2%), followed by G4P[8], two samples (5.4%); G3P[8], one sample (2.7%); and G9P[8], one sample (2.7%).

Molecular characterization of the NSP4 gene of human group A rotavirus samples from the West Central region of Brazil.

Nonstructural protein 4 (NSP4), encoded by group A rotavirus genome segment 10, is a multifunctional protein and the first recognized virus-encoded enterotoxin. The NSP4 gene has been sequenced, and five distinct genetic groups have been described: genotypes A-E. NSP4 genotypes A, B, and C have been detected in humans. In this study, the NSP4-encoding gene of human rotavirus strains of different G and P genotypes collected from children between 1987 and 2003 in three cities of West Central region of Brazil was characterized. NSP4 gene of 153 rotavirus-positive fecal samples was amplified by reverse transcriptase-polymerase chain reaction and then sequenced. For phylogenetic analysis, NSP4 nucleotide sequences of these samples were compared to nucleotide sequences of reference strains available in GenBank. Two distinct NSP4 genotypes could be identified: 141 (92.2%) sequences clustered with NSP4 genotype B, and 12 sequences (7.8%) clustered with NSP4 genotype A. These results reinforce that further investigations are needed to assess the validity of NSP4 as a suitable target for epidemiologic surveillance of rotavirus infections and vaccine development.

The circulation of human astrovirus genotypes in the Central West Region of Brazil

Out of 1,588 faecal samples of children taken from three locations of the Central West Region of Brazil, 57 were positive for astroviruses (HAstVs) using reverse transcription-polymerase chain reaction (RT-PCR). They were genotyped by nested RT-PCR and/or genomic sequencing. HAstV-1 (42.8 percent), HAstV-2 (23.2 percent), HAstV-3 (3.6 percent), HAstV-4 (14.3 percent) and HAstVs -5, -6, -7 and -8 (1.8 percent each) were detected. In Goiânia and Campo Grande, HAstV-1 was the most frequently detected genotype while in Brasília (DF) it was HAstV-2. Shifts in the circulation of astrovirus genotypes were observed in DF and Campo Grande. All samples collected by rectal swabs were viral negative. The astrovirus genotypes were detected in all age groups and there was no correlation between genotype and age group.

Adenovirus, calicivirus and astrovirus detection in fecal samples of hospitalized children with acute gastroenteritis from Campo Grande, MS, Brazil

We analyzed fecal samples from hospitalized children up to three years of age with acute gastroenteritis at Campo Grande, Mato Grosso do Sul, Brazil, from May 2000-January 2004. Astrovirus and calicivirus were detected by Reverse Transcription-Polymerase Chain Reaction and adenovirus was detected using the Rotavirus and Adenovirus combined immunoenzyme assay. Astrovirus, adenovirus and calicivirus were detected at rates of 3.1 percent, 3.6 percent and 7.6 percent, respectively. These results re-emphasize the need for the establishment of regional vigilance systems to evaluate the impact of enteric viruses on viral gastroenteritis.

Molecular characterization of the NSP4 gene of human group A rotavirus samples from the West Central region of Brazil

Nonstructural protein 4 (NSP4), encoded by group A rotavirus genome segment 10, is a multifunctional protein and the first recognized virus-encoded enterotoxin. The NSP4 gene has been sequenced, and five distinct genetic groups have been described: genotypes A-E. NSP4 genotypes A, B, and C have been detected in humans. In this study, the NSP4-encoding gene of human rotavirus strains of different G and P genotypes collected from children between 1987 and 2003 in three cities of West Central region of Brazil was characterized. NSP4 gene of 153 rotavirus-positive fecal samples was amplified by reverse transcriptase-polymerase chain reaction and then sequenced. For phylogenetic analysis, NSP4 nucleotide sequences of these samples were compared to nucleotide sequences of reference strains available in GenBank. Two distinct NSP4 genotypes could be identified: 141 (92.2 percent) sequences clustered with NSP4 genotype B, and 12 sequences (7.8 percent) clustered with NSP4 genotype A. These results reinforce that further investigations are needed to assess the validity of NSP4 as a suitable target for epidemiologic surveillance of rotavirus infections and vaccine development.

Rotavírus A em crianças de até três anos de idade, hospitalizadas com gastroenterite aguda em Campo Grande, Estado do Mato Grosso do Sul / Rotavirus A among hospitalized infants, up to three years of age, with acute gastroenteritis in Campo Grande, State of Mato Grosso do Sul

Através da eletroforese em gel de poliacrilamida e do ensaio imunenzimático combinado para rotavírus e adenovirus, foram analisadas 380 amostras fecais de crianças com até 3 anos, hospitalizadas com diarréia aguda, entre maio de 2000 e janeiro de 2004, em Campo Grande, MS. Do total de amostras, 88 (23,2 por cento) foram positivas para Rotavirus A. Dentre essas, 81 (92 por cento) tiveram padrão eletroferotípico definido, sendo 77 (87,5 por cento) de padrão longo e quatro (4,5 por cento) de padrão curto. A caracterização genotípica G e P foi feita por RT-Nested-PCR para 85 amostras, sendo 56 (65,9 por cento) genotipáveis para genótipo G. Dentre essas, 49 (87,5 por cento) foram G1, cinco (8,9 por cento) G4, uma (1,8 por cento) G3 e uma (1,8 por cento) G9. Considerando a genotipagem P, 37 (43,5 por cento) foram genotipáveis e todas eram P[8]. A associação G e P mais observada foi G1P[8], 33 (89,2 por cento) amostras; seguida de G4P[8], duas (5,4 por cento) amostras; G3P[8], uma (2,7 por cento) amostra; e G9P[8], uma (2,7 por cento) amostra.

Polyacrylamide gel electrophoresis and combined immunoenzyme assay for rotavirus and adenovirus were used to analyze 380 fecal samples from children up to three years of age who were hospitalized with acute diarrhea in Campo Grande, State of Mato Grosso do Sul, between May 2000 and January 2004. Among all the samples, 88 (23. 2 percent) were positive for Rotavirus A. Out of these, 81 (92 percent) had a defined electrophoretic pattern: 77 (87. 5 percent) with a long pattern and four (4. 5 percent) with a short pattern. Genotype G and P characterization was done by nested RT-PCR for 85 samples, of which 56 (65. 9 percent) were genotyped as type G. Among these, 49 (87. 5 percent) were G1, five (8. 9 percent) were G4, one (1. 8 percent) was G3 and one (1. 8 percent) was G9. The genotype was found to be type P in 37 samples (43. 5 percent) and all of these were P[8]. The G and P association most observed was G1P[8], with 33 samples (89. 2 percent), followed by G4P[8], two samples (5. 4 percent); G3P[8], one sample (2. 7 percent); and G9P[8], one sample (2. 7 percent).