Asunto(s)
Crianza de Animales Domésticos , Pollos/microbiología , Huevos/microbiología , Enfermedades de las Aves de Corral/microbiología , Organismos Libres de Patógenos Específicos , Animales , Embrión de Pollo , Pollos/virología , Huevos/virología , Enfermedades de las Aves de Corral/prevención & control , Enfermedades de las Aves de Corral/virologíaRESUMEN
A specific-pathogen-free flock of White Leghorns, which were housed conventionally and were previously serologically negative for all common poultry pathogens including avian adenoviruses, incurred an outbreak of adenovirus that was detected at about 39 weeks of age. The infection was detected serologically through the agar-gel precipitin test (AGPT) and also by a microneutralization test (MNT) adapted for 11 serotypes of avian adenovirus. The MNT detected specific antibodies to serotype-3 avian adenovirus (IBHV-Tipton) but no other serotype. While AGPT-positive sera drawn from the flock gradually declined from 54% to 17%, neutralizing-antibody levels rose sharply at 46 weeks of age to a peak that was maintained over the remaining 18 weeks of the flock's production.
Asunto(s)
Infecciones por Adenoviridae/veterinaria , Pollos , Enfermedades de las Aves de Corral/diagnóstico , Infecciones por Adenoviridae/diagnóstico , Animales , Anticuerpos Antivirales/análisis , Aviadenovirus/inmunología , Inmunodifusión , Pruebas de Neutralización , Organismos Libres de Patógenos EspecíficosRESUMEN
Chickens free of exogenous avian leukosis virus (ALV) infection, replicating endogenous ALV (Rous-associated virus-O), gs antigen, and chick helper factor were fully susceptible to induction of Marek's disease (MD) by ALV-free MD viruses. Dual infection with Rous-associated virus-2 and MD virus did not significantly alter the character of the MD lesions. Thus exogenous ALV infection was not requisite for MD virus-induced oncogenesis. Although participation of endogenous RNA tumor virus genes in MD lesion induction could not be excluded, expression of such genes in MD tumors as gs antigen was not established.
Asunto(s)
Herpesvirus Gallináceo 2/crecimiento & desarrollo , Enfermedad de Marek/microbiología , Animales , Virus de la Leucosis Aviar/crecimiento & desarrollo , Pollos , Virus Helper/crecimiento & desarrolloRESUMEN
Use of Marek's disease virus (MDV) in a neutralization test presents several problems, which are described, making this potentially useful test difficult. To obviate these difficulties, a plaque reduction test has been designed based on cross-neutralization of turkey herpesvirus (HVT) by serum-neutralizing MDV. The technique for such a neutralization test is outlined. Kinetics of development of neutralizing antibodies in chickens inoculated with HVT and MDV are described. The neutralization test can be used to evaluate viability of HVT vaccines and the possible role of neutralizing antibodies in the protection afforded by vaccination against MDV-induced tumors.