Biological and molecular characterization of Indian isolates of Newcastle disease virus from pigeons.

Five Newcastle disease virus (NDV) isolates from pigeons were characterized by biological and molecular methods. Four of the five isolates were found to be velogenic with high intracerebral pathogenicity indices (ICPI). The fusion protein cleavage site (FPCS) sequences of these isolates had multiple basic amino acids RRQKRF at positions 112-116 and a phenyl alanine at position 117 characteristic of velogenic isolates. Three of these velogenic isolates were phylogenetically related to mesogenic vaccine virus strain and the fourth one to a few exotic velogenic isolates. The lentogenic isolate obtained in this study was identical with the LaSota strain.