Full VP2 sequence analysis of Infectious Bursal Disease Virus (IBDV) in broiler chicken in Egypt

Infectious bursal disease virus (IBDV) is a highly infectious disease that severly affecting young chickens and alters  the immune system. In this study, 32 bursae samples collected from different broiler flocks (from Gharbia,  Behera,  Menofia,  and Kaferelsheikh) showed high mortality rate and bursal lesions during 2018 were examined. Obvious differences in genotyping between very virulent (vvIBD) and classical infectious bursal disease virus. Reverse transcriptase polymerase chain reaction (RT-PCR) was applied for IBD targeting the hyper variable region (HVR) of VP2 gene. The RT-PCR revealed that 20 samples positive, 10 representable samples were selected for genetic analysis from them 6 samples were selected for full VP2 geneticac analysis which revealed that these samples related to vvIBDV strains. The genotyping of Egyptian vvIBDV indicate massive evolution compared with previously isolated strains which indicate the persistence of vvIBDV in Egyptian poultry environment.