Cytopathic Alterations of Chicken Embryo Fibroblasts Induced by Newcastle disease virus of Goose Origin

The cytopathic effects on chicken embryo fibroblasts (CEFs), induced by Newcastle disease virus (NDV) derived from the novel disease outbreaks in geese during 1997 - 2000, were compared with those induced by chicken and pigeon isolates. When the CEFs were inoculated with goose isolates, cell abnormalities could be seen as early as 24 h PI, characterized by occurrence of some rounded,refractile and dark appearing cells. Then the lesions became more severe gradually, with a large number of syncytial cells appeared. The CEF monolayers were destroyed completely at 84-144 h PI, and the HA titers in the culture supernatants could get as high as 5-8 log2. When infected with ND viruses of chicken or pigeon origin, the earliest cell lesions were observed at 24 h PI, too. But it appeared that the alterations developed more rapidly in this occasion. The cells became rounded and refractile and necrosized, leaving empty areas (holes) in the cell sheet. At 60-84 h PI, the monolayers destroyed, with HA titers of 3-4 log2 in the culture supernatant. The syncytial cells contained far less nuclei than those formed after inoculation of goose isolates.