Rotavirus serotypes and electropherotypes identified among hospitalised children in São Luís, Maranhão, Brazil

During June 1997-June 1999 rotavirus infection was screened in infants aged up to 2 years and hospitalised with acute diarrhoea in São Luís, Northeastern Brazil. Altogether, 128 stool samples were collected from diarrhoeic patients and additional 122 faecal specimens from age- and- temporal matched inpatients without diarrhoea were obtained; rotavirus positivity rates for these groups were 32.0% (41/128) and 9.8% (12/122), respectively (p < 0.001). Both electropherotyping and serotyping could be performed in 42 (79.2%) of the 53 rotavirus-positive stool samples. Long and short electropherotypes were detected at similar rates - 38.1% and 40.5% of specimens, respectively. Overall, a G serotype could be assigned for 35 (83.3%) of specimens, the majority of them (66.7%) bearing G1-serotype specificity. Taking both electropherotypes and serotypes together, G1 rotavirus strains displaying long and short RNA patterns accounted for 30.9% and 19.0% of tested specimens, respectively; all G2 strains had short electropherotype. Rotavirus gastroenteritis was detected year-round and, in 1998, the incidence rates tended to be higher during the second semester than in the first semester: 45.2% and 26.1% (p = 0.13), respectively. Rotavirus infections peaked at the second semester of life with frequencies of 30.1% and 13.5% for diarrhoeic children and controls, respectively. While the six rotavirus strains bearing G2-type specificity were circulating throughout the whole study period, G1 serotypes (n = 27) emerged as from June 1998 onwards, 20 (74.1%) of which clustering in 1998. These data underscore the importance of rotaviruses in the aetiology of severe infantile gastroenteritis in Northeastern Brazil and sustain the concept that a future vaccine should confer protection against more than one serotype.

Diversity of genomic electropherotypes of naturally occurring equine herpesvirus 1 isolates in Argentina

The genomes of 10 equine herpesvirus 1 (EHV-1) strains isolated in Argentina from 1979 to 1991, and a Japanese HH1 reference strain were compared by restriction endonuclease analysis. Two restriction enzymes, BamHI and BglII, were used and analysis of the electropherotypes did not show significant differences among isolates obtained from horses with different clinical signs. This suggests that the EHV-1 isolates studied, which circulated in Argentina for more than 10 years, belong to a single genotype.

SHIFT IN HUMAN ROTAVIRUS DISTRIBUTION IN BELO HORIZONTE, BRAZIL DETECTED BY RIBONUCLEIC ACID ELECTROPHORESIS

Rotavirus has been considered the main agent of infectious diarrhea especially among younger children. We addressed the prevalence of rotavirus-associated diarrhea and the diversity of circulating electropherotypes by immunochromatography and RNA electrophoresis. Stool samples were taken from 391 children (267 with diarrhea) from the lower socioeconomic stratum who sought treatment in the Hospital Infantil João Paulo II/Belo Horizonte, during 2005 and 2006. Rotavirus was detected in 79/20.2% of subjects, 64/24.0% with diarrhea and 15/12.1% with no diarrhea. The virus was strongly associated with diarrhea (p = 0.003). A total of 76/19.4% and 69/17.6% rotavirus-positive children were identified by immunochromatography and electrophoresis, respectively. Rotavirus-associated diarrhea was more frequently detected in dry months (p < 0.001) and almost exclusively in children aged up to three years. Long profile strains prevailed (54/78.3%) but a shift toward short electropherotype was identified. Despite the decrease seen in 2006, rotavirus infection is still very common in our area. Although viral RNA electrophoresis is useful as a typing method, it should not be used exclusively in the diagnosis of rotavirus infection. We confirmed a shift from long to short profile strains, as already described for other South American countries.

Detection and Characterization of Rotavirus G and P Types from Children Participating in a Rotavirus Vaccine Trial in Belém, Brazil

This study sought the characterization of rotaviruses in a trial with a tetravalent rhesus-human rotavirus vaccine in Belém, Brazil in children who received three doses of vaccine or placebo in the 1st, 3rd and 5th months of life. Rotavirus electropherotypes, subgroups, G serotypes, G, [P] and [P],G genotypes were determined in 93.3%, 95.9%, 93.3%, 73.3%, 95.5% and 92.2% of isolates, respectively. Serotypes G1, G2 and G4 were detected in 58.9%, 30% and 4.4% of the cases, respectively. Rotavirus genotype G5 was detected for the first time in Northern region in 4.4% of the infections. Rotavirus genotypes P[8], P[4], P[6] and P[8+6] were detected in 54.5%, 26.7%, 12.2%, and 2.2% of the cases, respectively. The predominant genotypes were P[8],G1 and P[4],G2 with 53% and 26.6% of the infections, respectively. Unusual strains accounted for 20.5% including P[4],G1, P[6],G1, P[6],G4, P[6],G5, P[8],G2, P[8],G5. Mixed infections involving P[8+6],G2 and P[8+6],G1 were also noted. The neonatal P[6] strains associated with diarrhea were detected among children aged 9-24 months. To our knowledge, this study represents the first in Brazil to analyse, on molecular basis, rotavirus genotypes from children participating in a rotavirus vaccine trial. These results are of potential importance regarding future rotavirus vaccination strategies in Brazil.

Prevalência de rotavírus do grupo A em fezes diarréicas de bezerros de corte em sistema semi-intensivo de produção

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Ocorrência e diversidade molecular de rotavírus em rebanhos bovinos nas regiões Sudeste e Centro-Oeste do Brasil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Caracterização molecular dos genótipos G e P de rotavírus tipo G9 provenientes de crianças com gastrenterite aguda na região metropolitana de Belém, Pará, no período de 1999 a 2007

O rotavírus (RV) é o principal agente viral associado às gastrenterites, ocasionando em média 39% dos casos diarreicos que culminam em hospitalizações, sendo responsável por cerca de 520.000 óbitos entre crianças menores de cinco anos de idade a cada ano. Pertencem à família Reoviridae, gênero Rotavirus, possui RNA de dupla fita (dsRNA) com 11 segmentos codificando 12 proteínas, sendo seis estruturais (VPs) e seis não estruturais (NSPs). A proteína VP4, juntamente com a VP7, compõem a camada externa do RV, designando os genótipos P e G, respectivamente. Até o momento foram descritos 23 tipos G e 31 tipos P. O genótipo G9 emergiu em escala global e é possivelmente associado a manifestação clínica mais grave, estando geralmente acompanhado do genótipo P[8]. O genótipo G9 possui 6 linhagens distintas e o P[8] 4 linhagens. Este estudo objetivou caracterizar os genes VP7 e VP4 de RV do genótipo G9, circulantes na região metropolitana de Belém, Pará, no período de 1999 a 2007. O dsRNA viral de 38 amostras selecionadas foi extraído a partir das suspensões fecais e submetido à eletroforese em gel de poliacrilamida para determinação dos eletroferotipos, seguido da reação de seqüenciamento. Na presente investigação, foi possível a análise de 32 amostras selecionadas, sendo todas genótipo G9P[8] associadas ao eletroferotipo longo. A análise filogenética do gene VP7 demonstrou que as amostras G9 agruparam na linhagem 3 com elevados índices de similaridade, apresentando 8 substituições nucleotídicas. Contudo, apenas três modificações aminoacídicas foram observadas nas posições 43 (I→V), 66 (A→V) e 73 (Q→R), sendo estes resíduos 43 e 73 exclusivos das amostras do ano de 2007. A análise do gene VP4 demonstrou que as amostras P[8] agruparam na linhagem 3, identificando-se 15 substituições nucleotídicas, as quais ocasionaram quatro modificações aminoacídicas nos resíduos 108 (V→I), 172 (R→K), 173 (I→V) e 275 (K→R). As modificações nos resíduos 172 e 275 são exclusivos das amostras dos anos de 1999 a 2002. As amostras do presente estudo apresentaram elevada similaridade ao longo do tempo estudado. As amostras de 2007 foram as mais divergentes, tanto para o gene VP4 quanto para o gene VP7. É importante se proceder ao contínuo monitoramento do genótipo G9 na região metropolitana de Belém, a fim de detectar possíveis variantes emergentes que possam representar um desafio as estratégias de imunização atuais.