Comparative studies on duck viral enteritis (DVE) virus strains in geese.
DVE virus strains isolated from ducks (KPV strain), geese (KLM strain) and an attenuated strain designated DP were compared. Geese vaccinated with the avirulent strain showed 100% protection against the KPV strain, but no or only partial protection against strain KLM, depending on age and sex. Protection against the KLM strain was achieved by using a vaccine containing an avirulent strain and a strain of medium virulence. In goose embryo fibroblast (GEF) cell cultures the virulent strains caused small plaques with sharp margins, whereas the avirulent strain produced large plaques of uneven outline. In the cross-neutralisation tests all strains studied proved to be antigenically identical. The three strains showed similar sensitivity to heat-treatment (at 50 degrees C) and phosphonoacetic acid (PAA), while the KLM strain was slightly more resistant to trypsin-treatment.
Kisary
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Veterinary Medical Research Institute, Hungarian Academy of Sciences, Budapest, Hungary.
Zsak
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L