Isolation and identification of infectious bursal disease virus (IBDV) from internal organs of vaccinated chickens in Dakahlia Governorate, Egypt

Abstract

In the present study, a total of 35 samples including bursa of Fabricius, thymus, spleen, kidney and liver (7samples for each organ) were collected from vaccinated chickens flocks at Dakahlia Governorate, Egypt during the period from March 2015 to May 2015. Each sample was pooled randomly from three to five birds (25 to 44 days old). Trials for isolation of the suspected virus from the collected samples were carried out via chorioallantoic membranes (CAMs) of 9 days embryonated chicken eggs (ECEs), collected from hens free from infectious bursal disease virus (IBDV). Three egg passages were carried out for each sample. Hyperimmune serum was prepared against standard IBDV. IBDV in both field and egg passaged samples (after 3^rd passage) was identified by agar gel precipitation test (AGPT) and indirect fluorescence antibody test (IFAT). The results revealed that 30 samples (85%) including 7 (70%) samples from bursa of Fabricius and 6 (60%) samples from thymus, spleen and liver and 5(50%) samples from kidney, showed positive results in virus isolation. The positive results percentage by AGPT and IFAT for field samples were 88.5% (31 out of 35samples), while after 3 ^rd  passage in ECEs were 70% (22 out of 35 samples) and 88.5%(31 out of 35samples) respectively. The results indicate that the bursa of Fabricius is the best organ for IBDV isolation and AGPT and IFAT could be used for IBDV diagnosis.