الفهرس | Only 14 pages are availabe for public view |
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 ii 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. |