الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
Infectious bursal disease virus is highly contagious disease of chickens. IBD is
responsible for major economic losses in the poultry industry globally including
Egypt. In the present study, 50 chicken flocks suspected to be infected with IBDV in
Ismailia, Suez, Port-Said, North Sinai and South Sinai provinces were investigated for
IBD during 2015 to 2017. Bursal homogenate were tested using AGPT, conventional
RT-PCR and real time RT-PCR for the presence of IBDV. Out of the tested samples,
(11, 22%), (16; 32%) and (43; 86%) were positive by AGPT, cRT-PCR and rRT-PCR
respectively. Real time PCR was found to be the most sensitive and rapid test to detect
IBDV in clinical samples. The disease showed the highest prevalence during winter,
followed by autumn, spring and summer. Prevalence of disease within different age
groups of birds revealed the higher rate in birds aged more than 21 days old.
Partial sequencing analysis of VP2 gene of ten selected samples showed that the
most prevalent IBDV genotype is genotype 3 (vvIBDV) then genotype 1 (cv IBDV).
Full genome sequencing of two samples was done. First sample showed highest
Abstract
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identity and clustered with G-1 IBDV on both genome segments. On the other hand,
Second sample revealed occurrence of genetic reassortment within its genome
segments, with highest identity of segment A with vvIBDV and highest identity of
segment B with cvIBDV. Histopathological examination of bursal tissues belonged to
samples submitted for full genome sequencing revealed that both samples showed
picture similar to cvIBDV.