Isolation and Characterization of a Pathogenic Newcastle Disease Virus from a Natural Case in Indonesia

This study was performed to Isolate a velogenic Newcastle disease virus (NI) V) strain currently round in Indonesia for establishing a domestic reference virus lot future pathological and molecular epidemiological studies A elite ken suspected to have contracted Newcastle disease (ND) in a local outbreak in Bali was selected for NDV isolation Atrophy of lymphoid tissues such as the bursa of Fabric us. thymus. and spleen. intestinal haemorrhage, and oedema of the brain were observed in the chicken Histopathological examination revealed severe non-suppurative meningoencephalomyelitis characterised by neuronal necrosis, multifocal to diffuse ghosts, and perivascular cutting of mononuclear cells, hemorrhagic necrosis of the trachea, intestines and bursa of Fabrictus, and various degree of lymphoid depletion and necrosis of the lymphoid tissues After ND was confirmed immunohistochemically. the NDV was propagated by inoculating tissue homogenate of the diseased chicken in embryonated eggs Phylogenetic analysis based on the F gene nucleotide sequence revealed that this isolate belonged to genotype VII The deduced ammo acid sequence of the isolated NDV F protein at the cleavage site was (112)RRQKRF(117). which is typically found in virulent NDV isolates Pathogen city indexes such as the mean death time (MDT) and intracerebral pathogenicity index (ICPI) were 54 hi and 1 77, respectively Pathological findings. phylogenetic analysis. amino acid sequence of the F protein cleavage site. and pathogenicity index test results revealed the NDV isolate. designated as NDV/Bali-1/07, to be a novel Indonesian velogenic NDV strain belonging to group VII