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Rotavirus is the leading worldwide cause of gastroenteritis in children under five years of age. Even though there are some available vaccines to prevent the disease, there are limited strategies for challenging diarrhea induced by rotavirus infection. For this reason, researchers are constantly searching for other approaches to control diarrhea by means of probiotics. In order to demonstrate the ability of some probiotic bacteria to interfere with the in vitro rotavirus infection in MA104 cells, strains of Lactobacillus sp. and Bifidobacterium sp. were tested in MA104 cells before the viral infection. As a preliminary assay, a blocking effect treatment was performed with viable bacteria. In this screening assay, four of initial ten bacteria showed a slight reduction of the viral infection (measured by percentage of infection). L. casei (Lafti L26-DSL), L. fermentum(ATCC 9338), B. adolescentis (DSM 20083), and B. bifidum (ATCC 11863) were used in further experiments. Three different treatments were tested in order to evaluate protein-based metabolites obtained from mentioned bacteria: (i) cell exposure to the protein-based metabolites before viral infection, (ii) exposure to protein-based metabolites after viral infection, and (iii) co-incubation of the virus and protein-based metabolites before viral infection to the cell culture. The best effect performed by protein-based metabolites was observed during the co-incubation assay of the virus and protein-based metabolites before adding them into the cell culture. The results showed 25 and 37% of infection in the presence of L. casei and B. adolescentis respectively. These results suggest that the antiviral effect may be occurring directly with the viral particle instead of making a blocking effect of the cellular receptors that are needed for the viral entrance.

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RESUMO

Identificación de Norovirus Humano (HNoV) en muestras de estiércol de cerdos domésticos. Objetivo: determinar la presencia de NoVs como posible agente zoonótico causal de diarrea aguda entre cerdos y humanos. Materiales y métodos: se recolectaron un total de 77 muestras diarreicas provenientes de niños menores de cinco años y de cerdos menores de dos meses de la población La Chamba en el Tolima, Colombia. Estas muestras fueron transportadas al Laboratorio de Virología de la Pontificia Universidad Javeriana en Bogotá, donde inicialmente se les realizó extracción con Trizol-reagent, siguiendo las instrucciones del fabricante. Una vez obtenido el RNA, el siguiente paso fue hacer la RT-PCR para obtener el producto de amplificacion esperado para NoVs de 213 pb. Finalmente, las muestras positivas obtenidas en la RT-PCR fueron secuenciadas y analizadas mediante métodos bioinformáticos. Resultados: se obtuvieron seis muestras positivas de diarrea de niños y una muestra positiva de diarrea de cerdos, las cuales se evidenciaron en una banda de 231 pb. Cinco de las seis muestras positivas en niños y la muestra positiva en cerdos fueron secuenciadas y analizadas. Conclusiones: dada la estrecha relación genética que se evidencia entre las secuencias del cerdo y el humano, este podría ser un indicio de que exista la posibilidad de un animal en común como reservorio para cepas de humano u otras cepas de animales...

Objective. To determine the presence of NoVs as a possible causal zoonotic agent of acute diarrhea in pigs and humans. Materials and methods. We collected a total of 77 samples from diarrheal children under 5 years and pigs under 2 months from La Chamba town in Tolima, Colombia. These samples were transported to the Laboratory of Virology of the Pontificia Universidad Javeriana in Bogotá, and extraction with Trizol-reagent was done following the manufacturer’s instructions. After obtaining the RNA, the next step was to perform RT-PCR for obtaining the expected amplification product of 213- bp NoVs. Finally, the positive samples obtained in the RT-PCR were sequenced and analyzed by bioinformatics methods. Results. Six positive diarrheic samples from children and a positive diarrheic sample from pigs were detected by a band of 231 bp. Five of the six positive samples in children and the positive pig sample were sequenced and analyzed. Conclusion. Given the close genetic relationship between pig and human sequences, this could be an indication of the potential existence of a common animal acting as a reservoir for human or other animal strains...

Identificação de Norovírus Humano (HNoV) em amostras de suínos domésticos. Objetivo. Determinar a presença de NoVs como possível agente zoonótico causal de diarréia aguda entre porcos e seres humanos. Materiais e métodos. Foram coletadas um total de 77 amostras de crianças diarréicas menores de cinco anos e porcos com menos de dois meses da população “La Chamba” Tolima-Colômbia. Estas amostras foram transportadas ao laboratório de virologia da Pontifícia Universidade Javeriana - Bogotá, onde foram inicialmente submetidas à extração com Trizol reagment e seguindo as instruções do fabricante, após a obtenção do RNA o próximo passo foi realizar a RT-PCR para obter o produto de amplificação esperado para NoVs de 213 bp. Finalmente as amostras positivas obtidas no RT-PCR foram seqüenciadas e analisadas por métodos de bioinformática. Resultados. Foram obtidas seis amostras positivas de diarréia nas crianças e uma amostra positiva de diarréia em suínos, as que foram representadas em uma banda de 231 pb. Cinco das seis amostras positivas em crianças e a amostra positiva em suínos foram seqüenciadas e analisadas. Conclusões. Dada a estreita relação genética que se manifesta entre as seqüências de suínos e humanos, isso poderia ser uma indicação de que existe a possibilidade de um animal comum como reservatório para o humano ou outras cepas de animais...

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