Rotavirus G2P[4] detection in fresh vegetables and oysters in Mexico City.

Rotaviruses are the principal cause of dehydration caused by diarrhea in children younger than 2 years of age. Although these viral infections have mainly been associated with ingestion of fecally contaminated food and water, few studies have addressed the presence of the virus in food that is consumed raw or slightly cooked. In this work, 30 oyster samples and 33 vegetable samples were examined for the presence of rotavirus genotypes to evaluate their potential to produce gastrointestinal infections. The rotaviruses were identified by reverse transcriptase PCR amplification of the VP7 gene. G and P genotyping was also performed by reverse transcriptase PCR, with a detection sensitivity of up to 15 PFU/ml. Rotaviruses were found in 17 (26.9%) of 63 samples (10 oysters and 7 vegetables). The G2 genotype was found in 11 (64.7%) of 17 of the rotavirus strains, and 16 (94.1%) of 17 had the P[4] genotype. The combined genotypes found most frequently were G2P[4] (10 [58.82%] of 17), GNTP[4] (6 [35.29%] of 17), and G2P[NT] (1 [5.8%] of 17).

Búsqueda de rotavirus en muestras fecales resuspendidas en medio de transporte utilizado para el diagnóstico bacteriológico / Rotaviruses search in rectal samples placed on transport medium for bacteriological diagnosis

Rutinariamente el diagnóstico de gastroenteritis en niños hospitalizados no incluye la búsqueda de rotavirus como agente causal. Para el examen bacteriológico se utiliza una muestra de hisopo rectal colocada en medio de transporte, la cual podría servir también, para la búsqueda de rotavirus. El objetivo del presente trabajo fue determinar la presencia de rotavirus en 105 muestras de hisopos rectales resuspendidos en medio de transporte de Stuart, provenientes de pacientes menores de 5 años de edad, hospitalizados con un cuadro gastrointestinal en el Hospital General Regional 25 del IMSS. Estas muestras previamente fueron reportadas como negativas para agentes causales de diarrea, a excepción de una, que fue positiva para Vibrio Cholerae. A las 105 Muestras se les realizó la extracción del RNA viral y se analizaron por electroforesis en geles de poliacrilamida al 10 por ciento. Se detectaron 28 positivas para rotavirus, de las cuales 26 presentaron un patrón electroforético de tipo largo y 2 de tipo corto. La distribución de los segmentos de RNA en grupos de 4, 2, 3 y 2 bandas, sugiere que en todos los casos se trata de rotavirus del grupo A. Estos resultados muestran que es posible detectar la presencia de rotavirus, utilizando la misma muestra que se toma para el diagnóstico bacteriológico y que el genoma viral presente en la muestra puede conservarse en congeladores de tipo doméstico por periodos prolongados, lo cual es muy conveniente en la realización de estudios epidemiológicos

Inhibition of three alphaherpesviruses (Herpes simplex 1 and 2 and pseudorabies virus) by heparin, heparan and other sulfated polyelectrolytes

The first step of the herpes virus infection is the attachment to heparan sulfate molecules on the cellular membrane. In order to improve the characterization of this phenomenon, we compared the inhibitory effect of six sulfated polyelectrolytes (PE): heparin, heparan, low molecular wight heparin, chondroitin, dextran and protamine on plaque formation by pseudorabies virus (PRV) were compared. The PE with the highest antiherpetic effect was heparin, followed by dextran sulfate. Heparan sulfate, which has been proposed as the initial receptor of herpes virus on the cell surface showed and effect 100-fold lower than heparin. Comparative inhibition curves of heparin and heparan sulfate against three herpes viruses: herpes simplex virus 1 (HSV-1), HSV 2 and PRV showed similar kinetics of inhibition of plaque formation, suggesting these viruses could share similar cell adsorption mechanisms