Some biological and physico-chemical properties of egg drop syndrome (EDS) avian adenovirus strain B8/78

Characterisation of adenoviruses isolated from geese

Viruses isolated from liver and gut of dead 2- to 4-week-old goslings were identified as adenoviruses. The main characteristics of the strains were: development of intranuclear inclusion bodies in virus-infected cells; a buoyant density of the infective particles in CsC1 of 1.33-1.34 g/ml; icosahedral virions measuring 78-83 nm in diameter which had no envelope; a linear duplex DNA genome with a molecular weight of 25-29 x 10(6) daltons. These adenoviruses did not cross-react in neutralisation tests with 11 fowl, two turkey and two duck adenovirus serotypes, however, they shared a common complement-fixing antigen with fowl adenoviruses. Based on the results of the cross-neutralisation tests and on the cleavage pattern of DNAs by BamHI and Hind III restriction endonucleases, the seven adenovirus strains studied represent three distinct goose adenovirus serotypes. The goose adenoviruses caused neither clinical symptoms nor pathological lesions after infection of 3-day-old goslings.

Biological characterisation of an Indian isolate of egg drop syndrome-76 virus

An isolate of egg drop syndrome-76 virus replicated best in primary chicken embryo liver cells and less well in duck embryo liver cells, duck embryo fibroblast cells and chicken embryo kidney cells. The cytopathic effect in chicken embryo liver cells was marked by the presence of round and refractile cells and detachment of cells from the glass surface. The intranuclear eosinophilic inclusion bodies were observed by 24 to 48 hours after infection. No virus multiplication was observed in primary quail embryo fibroblast cells, chicken embryo fibroblast cells or mammalian cells like Vero, BHK-21 and MDBK. Duck embryos supported the maximum growth of the virus, with allantoic fluid having the highest haemagglutinin titre, followed in order by chorioallantoic membrane, skin and internal organs. Chicken and quail embryos did not support the growth of the virus.

Purification and hemagglutinating properties of egg drop syndrome 1976 virus

We purified three populations of virus particles, F7, F9 and F17, with buoyant densities of 1.34, 1.33 and 1.29 g/ml, respectively, in CsCl equilibrium density gradients from cultures of chick embryo liver cells infected with the H-162 strain of the virus of egg drop syndrome 1976. F9 particles were infectious complete virions and most F17 particles were empty particles. F7 particles were less infectious, and had little capacity of hemagglutination (HA). HA titers were the same at 4 degrees and 37 degrees C and maximal between pH 6.4 and 8.4 and ionic strength from 0.14 to 0.54 M of NaCl. HA titer was inversely proportional to erythrocyte concentration. Potassium periodate destroyed markedly the infectivity of the virus and partially its HA activity at 37 degrees C. HA activity was stable at 56 degrees C or lower temperatures and destroyed at 80 degrees C. Trypsin, alpha-chymotrypsin, papain, ficin and neuraminidase had no effect on HA activity. Alpha-chymotrypsin destroyed the receptor for the virus on chicken erythrocytes, whereas trypsin and neuraminidase did not affect the receptor.