Rinotraqueitis infecciosa bovina (RIB). Caracterización molecular de una cepa colombiana de herpesvirus bovino tipo 1

Resumen El Herpesvirus Bovino 1(HVB-1) produce, en el ganado, enfermedades respiratorias, genitales y otros sintomas clinicos que ocasionan perdidas economicas importantes. Los estudios de prevalencia en Colombia indican que este agente esta ampliamente distribuido, pero las evidencias clinicas y virologicas son escasas. Por esta razon se ha propuesto que las cepas de HVB-1 que circulan en Colombia son diferentes a las que circulan en aquellos paises donde la RIB constituye un serio problema de salud animal. A pesar de los intensos y extensos esfuerzos para tratar de aislar el virus, hechos desde 1993 (2416 muestras probadas en nuestro laboratorio), ademas del esfuerzo de otros grupos en el pais, no se han logrado aislamientos. En este estudio se informa sobre la caracterizacion molecular de uno de los aislamientos hecho en Colombia en los ultimos 20 anos. El perfil polipeptidico y los RFLPs indican que se trata de una cepa de HVB-1 subtipo 2b (tipo VPI). Los virus pertenecientes a este subtipo se han asociado principalmente a VPI y BPI. Este hallazgo, junto con la carencia de aislamientos, concuerda con la hipotesis de que las cepas virales que circulan en el pais son de baja virulencia y que la infeccion no es un problema de gran impacto economico. Palabras clave: aislamiento, patron de restriccion, perfil proteico. Summary Bovine Herpesvirus 1 (BHV-1) affects cattle and is associated with respiratory disease (IBR), reproductive tract disorders (IPV and IPB) and other symptoms which may cause significant economic losses. Serologic studies of prevalence in Colombia indicate that this agent is distributed in relatively wide manner, but the clinic and virological evidence is scarce. It have been proposed therefore that the of HVB-1 strains that exist in this country are different from those circulating in other regions of the world where the virus is tightly associated with disease and economic losses. Several groups have tried to isolate the virus since 1993; particularly in our laboratory we have tested 2416 samples, but all these efforts have been unsuccessful. This report is about molecular characterization of only one isolate in the last 20 years, which was obtain by means of corticosteroid treatment of a seropositive bull. The polipeptide and RFLPs profiles indicated that this isolate corresponds to BHV-1 subtype 2b; which is associated with reproductive symptoms but not with abortion. Altogether, this result is in agreement with the hypotesis that the BHV-1 does not circulate widely in Colombia and are only mildly associated  with disease ; therefore, at this point in time this does not seem to be a problem of economic importance in our country. Key words: i solation, protein profile, restriction patterns.