Characterization of Newcastle Disease Viruses Isolated from Migratory Waterfowl in the Atlantic Flyway

Abstract

Four isolants of Newcastle disease virus (NDV) obtained from free-flying Canada geese in the Atlantic flyway were characterized and compared with the B1, LaSota, Roakin, and Texas-GB strains of NDV. The 4 isolants were identified as lentogenic strains on the basis of embryo mean death times of greater than 100 hours and relative lack of pathogenicity for 1-day-old and 3-week-old chickens. The hemagglutinin of 2 of the isolants was stable at 56 C for 15 minutes, 1 for 30 minutes, and the other for at least 2 hours. When held at 4 C for 24 hours, none of the 4 isolants could be eluted from chicken erythrocytes. All 4 of the isolants produced plaques in chicken embryo fibroblast cell cultures without additives, whereas the B1 and LaSota strains did not. The 4 lentogenic NDV isolants from Canada geese differed in many respects from currently used commerical vaccine strains (B1 and LaSota).

Phylogenetic Diversity among Low-Virulence Newcastle Disease Viruses from Waterfowl and Shorebirds and Comparison of Genotype Distributions to Those of Poultry-Origin Isolates

“…Velogens, the most virulent viruses, are those that may cause extensive hemorrhagic lesions, particularly in the gastrointestinal tract (viscerotropic), and/or a predominance of nervous signs (neurotropic) (4). vNDV are considered exotic to U.S. poultry; however, the lentogenic strains are common among domestic poultry (27,32,36,45) and wild bird populations (25,27,43,50). The occurrence of vNDV infections in birds is a notifiable event, and when these infections occur in poultry, trade restrictions are imposed.…”

Immunogenicity of Infectious Bursal Disease Virus Strains Isolated in India

“…Chick embryo fibroblast (CEF) cell culture were prepared using 9 to 11 d old embryos as described by Rosenberger et al (1975) in 25 cm2 tissue culture flask (Greiner, Germany). The cell cultures were grown in glasgow modified eagle's medium (GMEM) containing 10% calf serum.…”

Characterization of the antigenic, immunogenic, and pathogenic variation of infectious bursal disease virus due to propagation in different host systems (bursa, embryo, and cell culture). I. Antigenicity and immunogenicity

“…CEF were prepared from 10-day-old specific pathogen free (SPF) chicken embryos (SPAFAS Inc., Norwich, CT, USA) as previously described (Rosenberger et al, 1975). Cell concentrations were adjusted to 5 ´10 5 CEF/ml and plated in tissue culture flasks (20 ml CEF/T 75 cm 3 or 40 ml CEF/ T 150 cm 3 ) for virus growth or in 96-well flat-bottomed plates (100 m l CEF/well) for microneutralization assays.…”