Biological properties of the episootic isolate of the virus of infectious bursal disease

Abstract

This article represents research data about biological characteristics of «Yuzhna-Holding» infectious bursal disease isolate, obtained in Simferopol, AR Crimea, Ukraine in 2010. The specificity of this epizootic isolate is confirmed with positive results in neutralization reaction as well as with plaque-assay method. The field isolate has shown its high adaptive capability for cultivation in primarily trypsinized chicken fibroblast cell cultures. The highest infective activity titer of «Yuzhna-Holding» isolate was 8,65 lg TCD₅₀/cm³ on fifth passage when cultivating in QEF CC. The pathogenicity of «Yuzhna-Holding» isolate was proved with bioassay on 47-day old chickens of«Borkivska barvysta» breed. The isolate caused typical clinical signs and internal lesions when intranasal/ocular inoculating of 0,400 y.l of native extra embryo liquid.