DETECTION OF NEWCASTLE DISEASE VIRUS IN INFECTED CHICKEN EMBRYOS AND CHICKEN TISSUES BY RT-PCR

RT-PCR for the detection of Newcastle disease virus (NDV) in allantoic fluids of SPF embryonated eggs as well as in tissues of SPF chickens infected experimentally is described. The method proved to be specific as all tested NDVs were detected and no cross reaction with other RNA viruses was observed. Sensitivity of the method was established at 10 5 ELD50/0.1 ml. To detect NDV in chicken tissues, SPF chickens were inoculated with 10 6 EID50 of 3 NDV reference strains: La Sota (lentogenic), Roakin (mesogenic) and Italy (velogenic pigeon variant) and 5 d p.i. various tissue samples were aseptically collected followed by RT-PCR and virus isolation on SPF embryos. The results showed high concordance: 93% (La Sota and Italy) to 100% (Roakin) between both methods.