Hussein H A, Emara M M, Samy A M and Shalaby M A
Department of Virology,
Faculty of Veterinary Medicine, Cairo University, Giza- Egypt.
Newcastle
disease virus (NDV) is a single serotype with sufficient antigenic differences
among the isolates and strains. In this study, 75 field samples were collected
from 52 different broiler and breeder flocks representing different
governorates in Egypt. Attempts for virus isolation using embryonated chicken
eggs (ECE) and cell culture were carried out. The antigenic diversity and
biological properties of the 71 ECE-isolated local field strains of NDV were
studied using different assays including hemagglutination, hemagglutination
inhibition and hemolysis activity. Out of 20 selected local NDV isolates that
were propagated in different cell lines, 14 field strains were successfully
adapted on Vero cells. These cell culture adapted local strains of NDV were
further antigenically characterized using ELISA, neutralization test, and
genomic detected by reverse transcription- polymerase chain reaction assay
(RT-PCR). The obtained results clearly demonstrate the differences in the
surface polypeptides of these viruses and confirm the antigenic variability and
heterogeneity of the local field strains of NDV, even within the same content.