G26P[19] rotavirus A strain causing acute gastroenteritis in the American continent

In Brazil, the rotavirus A genotype G26 was first identified in suckling piglets, while the P[19] genotype has not been identified in any animal species so far. This report details the genetic characterisation of a G26P[19] RVA strain detected from an eight year-old child, vaccinated with Rotarix®, hospitalised with acute diarrhoeal disease in Rio de Janeiro in 2015. Most likely, the genome constellation (I5-R1-C1-M1-A8-N1-T1-E1-H1) observed in the G26P[19] Brazilian strain was a result of interspecies transmission events between humans and pigs. In addition, a rearrangement in the NSP5 gene was observed downstream of the 3' non-coding region.

Epidemiologia das rotaviroses antes e após a introdução da vacina / Rotavirus epidemiology before and after vaccine introduction

OBJETIVOS: Avaliar a prevalência e a circulação dos genótipos de rotavírus, antes e após a introdução da vacina oral contra rotavírus humano, bem como verificar uma possível mudança na faixa etária de ocorrência da infecção pelo RV-A. MÉTODOS: Trata-se de um estudo transversal realizado no período de 2002 a 2011, em Juiz de Fora, MG. Foram avaliados 1.144 espécimes fecais diarreicos, obtidos de crianças de 0 a cinco anos não hospitalizadas, que foram analisadas por PAGE e RT-PCR. Os dados relativos à prevalência e distribuição etária dos casos de rotavirose foram analisados pelo teste χ2 (p < 0,05), utilizando-se o programa SPSS, versão 13.0. RESULTADOS: Infecções por rotavírus foram detectadas em 9,35% (107/1.144) das amostras, com prevalências variando de 11,12% (90/809) no período pré-vacinal a 5,07% (17/335) no pós-vacinal (p = 0,001). Dentre as amostras caracterizadas, os genótipos mais frequentemente detectados foram G1P[6] (6/33 = 18,2%) no período 2002-2005 e G2P[4] no ano de 2006 (11/33 = 33,3%) e no período 2007-2011 (5/33 = 15,2%). Observou-se, ainda, uma redução significativa no número de casos de rotavirose em crianças de 0 a 36 meses, após a introdução da vacina. CONCLUSÕES: O estudo revelou queda significativa na prevalência de rotavírus, principalmente na faixa etária de 0 a 36 meses, no período 2007-2011, bem como redução na circulação do genótipo G1.

OBJECTIVES: To evaluate the prevalence and circulation of rotavirus genotypes before and after the introduction of oral vaccine against human rotavirus (OVHR), and to check for a possible change in the age of occurence of the infection by RV-A. METHODS: This was a cross-sectional study conducted between 2002-2011, in the city of Juiz de Fora, state of Minas Gerais, Brazil. A total of 1,144 diarrheal stool specimens were obtained from nonhospitalized children aged between 0 and 5 years, and analyzed by polyacrylamide gel electrophoresis and reverse-transcription polymerase chain reaction for genotype characterization. Data on prevalence and age distribution of rotavirus cases were analyzed through the chi-squared test (p < 0.05), using SPSS, release 13.0. RESULTS: Rotavirus infection was detected in 9.35% (107/1,144) samples, with prevalence rates ranging from 11.12% (90/809) in the pre-vaccine to 5.07% (17/335) in the post-vaccine period (p = 0.001). Among the samples tested, the most frequently detected genotypes were G1P[6] (6/33 = 18.2%) in the period between 2002 and 2005 and G2P[4] in 2006 (11/33 = 33.3%) and in the period between 2007 and 2011 (5/33 = 15.2%). There was also a significant reduction in the number of cases of rotavirus disease in children aged between 0 and 36 months after the vaccine introduction. CONCLUSIONS: The study evidenced a significant decrease in the prevalence of rotavirus, mainly in children aged between 0 and 36 months in the 2007-2011 period, as well as a reduction in G1 genotype circulation.

Marine natural seaweed products as potential antiviral drugs against Bovine viral diarrhea virus

Bovine viral diarrhea virus (BVDV) is an etiologic agent that causes important economic losses in the world. It is endemic in cattle herds in most parts of the world. The purpose of this study was to evaluate the in vitro cytotoxic effect and antiviral properties of several marine natural products obtained from seaweeds: the indole alkaloid caulerpin (CAV, 1) and three diterpenes: 6-hydroxydichotoma-3,14-diene-1,17-dial (DA, 2), 10,18-diacetoxy-8-hydroxy-2,6-dolabelladiene (DB1, 3) and 8,10,18-trihydroxy-2,6-dolabelladiene (DB3, 4). The screening to evaluate the cytotoxicity of compounds did not show toxic effects to MDBK cells. The antiviral activity of the compounds was measured by the inhibition of the cytopathic effect on infected cells by plaque assay (PA) and EC50 values were calculated for CAV (EC=2,0± 5.8), DA (EC 2,8± 7.7), DB1 (EC 2,0±9.7), and DB3 (EC 2,3±7.4). Acyclovir (EC50 322± 5.9) was used in all experiments as the control standard. Although the results of the antiviral activity suggest that all compounds are promising as antiviral agents against BVDV, the Selectivity Index suggests that DB1 is the safest of the compounds tested.

Rotavirus A genotype G1P[8]: a novel method to distinguish wild-type strains from the Rotarix® vaccine strain

Rotaviruses are important enteric pathogens for humans and animals. Group A rotaviruses (RV-A) are the most common agents of severe gastroenteritis in infants and young children and vaccination is the most effective method to reduce RV-A-associated diseases. G1P[8], the most prevalent RV-A genotype worldwide, is included in the RV-A vaccine Rotarix®. The discrimination between wild-type G1P[8] and vaccine G1P[8] strains is an important topic in the study of RV-A epidemiology to manage outbreaks and to define control measures for vaccinated children. In this study, we developed a novel method to segregate the wild-type and vaccine strains using restriction endonucleases. The dsRNA from the Rotarix® vaccine was sequenced and the NSP3 gene was selected as the target gene. The vaccine strain has a restriction pattern that is different than that of wild-type RV-A G1P[8] isolates after digestion with the restriction endonuclease BspHI. This pattern could be used as a marker for the differentiation of wild-type G1P[8] strains from the vaccine strain.

First detection of a human astrovirus type 8 in a child with diarrhea in Belém, Brazil: comparison with other strains worldwide and identification of possible three lineages

This study describes the genetic relationships of the first human astrovirus type-8 (HAstV-8) detected in Belém-Brazil, during a public hospital-based study. This strain was compared with other HAstV-8 strains identified elsewhere which have sequences available at GeneBank. The regions ORF1a (primers Mon348/Mon340) and ORF2 (primers Mon269/Mon270) were analyzed by nucleotide sequencing and a high similarity rate was observed among the Belém strain and other HAstV-8 strains. In ORF1a, homology values of 93-100 por cento were detected, and in ORF2 96-99 por cento. Considering the sequence variation (7 por cento) observed in ORF2 region, it was suggested that HAstV-8 strains could be divided in three different lineages.

Prevalence and genetic diversity of astroviruses in children with and without diarrhea in São Luís, Maranhão, Brazil

Human astroviruses (HAstV) have been increasingly identified as important etiological agents of acute gastroenteritis in children up to five years old. The aim of this study was to determine the prevalence and genotype diversity of HAstV in children with symptomatic and asymptomatic infections in São Luís, Maranhão, Brazil. From June 1997 to July 1999 a total of 183 fecal samples 84 from symptomatic and 99 from asymptomatic children were tested by enzyme immunoassay for HAstV. Prevalence rates were found to be 11 and 3 percent for symptomatic and asymptomatic children, respectively. Reverse transcription-polymerase chain reaction (RT-PCR) was carried out in 46 specimens (26 symptomatic and 20 asymptomatic) including the 12 samples that were positive by enzyme immunoassay (EIA). The overall positivity yielded by both methods was 8 percent (15/184); of these, 11 percent (9/84) for symptomatic and 5 percent (5/99) for those without symptoms or signs. Sequence analysis of amplicons revealed that HAstV-1 genotype was the most prevalent, accounting for 60 percent of isolates. Genotypes 2, 3, 4, and 5 were also detected, as one single isolate (10 percent) for each type. Variations in the sequences were observed when Brazilian isolates were compared to prototype strains identified in the United Kingdom. No seasonal pattern of occurrence was observed during these two years of study, and peak detection rate was observed in children aged between 3 and 6 months in the symptomatic group, and between 18 and 24 months in the controls.

Infecçäo pelo Parvovírus Canino no Rio de Janeiro: um estudo de cinco anos / Canine parvovirus infection in Rio de Janeiro: a five-year study

Amostras fecais de cäes com até seis meses de idade, com gastrenterite, foram testadas para a presença do parvovírus canino (CPV) pelo teste de hemaglutinaçäo (HA) e confirmadas como positivas pelo teste de inibiçäo da hemaglutinaçäo. Noventa e duas das 208 amostras recebidas no período de abril de 1995 a novembro de 2000 foram positivas. Aproximadamente, 76 por cento das amostras foram obtidas de cäes entre dois e quatro meses de idade. Entre os 92 animais positivos para CPV-2,28 tinham sido vacinados, e para 11 destes o resultado positivo do HA poderia ser devido a detecçäo do vírus vacinal. Através da reaçäo em cadeia pela polimerase, pode-se confirmar a infecçäo pelo vírus selvagem em nove dos 11 animais vacinados. Neste estudo näo foi possível observar que fatores como sexo ou raça possam ser importantes no desenvolvimento da doença. No período estudado, o parvovírus canino pode ser detectado, em todos os meses do ano, näo apresentando sazonalidade definida.

Genetic and antigenic analysis of adenovirus type 3 strains showing intermediate behavior in standard seroneutralization test

During an epidemiological survey of acute respiratory infection in Rio de Janeiro, among 208 adenovirus isolates, we found two strains that we were not able, by a standard neutralization procedure, to distinguish between type 3 or 7. However, DNA restriction pattern for the two strains with different enzymes were analysed and showed a typical Ad3h profile. Using a cross-neutralization test in which both Ad3p and Ad7p antisera were used in different concentration against 100 TCID 50 of each adenovirus standard and both isolates, we were able to confirm that the two isolates belong to serotype 3. An hemagglutination inhibition test also corroborated the identification of both strains as adenovirus type 3. Comparing Ad3h and Ad3p genome, we observed 16 different restriction enzyme sites, three of which were located in genomic regions encoding polypeptides involved in neutralization sites.

Genomic characterization of adenovirus serotype 7 isolated in Brazil from acute respiratory disease patients during the period from 1980 to 1991

Quarenta amostras de Adenovirus tipo 7 foram analisadas por digestao com as enzimas de restricao BamHI, SmaI, EcoRI e HindIII. Estas amostras foram coletadas de pacientes apresentando doenca respiratoria aguda durante os anos de 1980 a 1991. Somente dois tipos genomicos foram encontrados: Ad7b e Ad7e, sendo que Ad7b (87,5 por cento) foi mais frequente que Ad7e (12,5 por cento). O tipo genomico Ad7e apareceu nos anos 1980, 1981 e 1983. Ad7b apareceu durante 1982 e seguiu sendo o unico tipo genomico encontrado de 1984 a 1991. Ambos os tipos genomicos foram responsaveis por infeccoes do trato respiratorio superior (ITRS) e inferior (ITRI), porem a proporcao ITRI/ITRS e mais alta para Ad7b (25/6) que para Ad7e (1/4)