In-Vitro Identification of Infectious Bursal Disease Virus Isolates from Dakahlia Governorate, Egypt through the Period from 2017 to 2018.

Document Type : Original Articles


1 Department of virology, Faculty of Veterinary Medicine, Mansoura University

2 Department of Virology, Faculty of Veterinary Medicine, Mansoura university


Objective: Isolation, serological and molecular characterization of IBDV from field samples.
Design: Descriptive study.
Samples: A total of 55 chicken farms were studied during the period from March 2017 to August 2018. Three diseased birds were collected from each farm; their organs were pooled and considered as one sample.
Procedures: The 55 collected samples were isolated on the chorioallantoic membrane (CAM) of embryonated chicken eggs (ECEs) for 3 passages and identified by changes in embryo and CAM. The embryo and CAM homogenates from the 3rd passage of 50 samples showing embryonic changes were tested by agar gel precipitation test (AGPT). Reverse transcriptase-polymerase chain reaction (RT-PCR) was done for IBDV confirmation in 10 selected isolates. PCR product of selected sample was sequenced, obtained nucleotide and deduced amino acid sequences were analyzed together with other sequences from GenBank.
Results: Out of 55 tested samples, 43, 48 and 50 samples showed embryonic changes in the 1st, 2nd and 3rd passages respectively. In AGPT, 48 isolates showed precipitin lines. All RT-PCR tested isolates gave the expected band at 743 bp. Sequence analysis revealed that the studied isolate was closely related to Egyptian genogroup 3 vvIBDV with 95.8% to 98.1% identity. The studied isolate showed characteristic vvIBDV serine rich heptapeptides SWSASGS with characteristic vvIBDV VP2 hyper variable region conserved amino acids.
Conclusion and clinical relevance:
Nucleotide and amino acid sequences of IBDV-VP2 hyper variable region is a valuable tool for characterization of vvIBDV.


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