Molecular characterization of Hyper variable Region of the classical and very virulent Egyptian isolates of IBDV
Abstract: Many recent outbreaks of infectious bursal disease in commercial chicken flocks worldwide are due to the spread of very virulent IBDV.Two Egyptian isolates of IBDV isolated from Giza (Giza/2000) and Kalubia (Kal/2001) governorates were characterized by RT/PCR-RFLP assay of a 643 bp hyper variable region of VP2 gene using BstNI.Mbol and Sspl restriction enzymes.the presence of Sspl site in Giza/2000 identified it as vvIBDV while the abscence of this site in Kal/2001 beside the obtained profile of BstNI and Mbol restriction enzymes identified it as classic strain. This was confirmed by sequence analysis of these RT/PCR products of the hyper variable region and the dedused a.a sequence 183-360. Kal/2001 has the highest identity on both nucleotide and amino acid levels 99.4% and 98.8% to the classical strains Cu-1. D78 and PBG-98,While Giza/2000 has the highest identity 98.3-98.1% on nucleotide level and 98.3% on a level to the vvIBDVs. The multiple alignment of the two Egyptian isolates with different IBDV serotype I strains showed that Giza/2000 isolate shared three unique a.a residues at positions 222A, 2561 and 2941 that were found only in vvIBDV as well as the conserved serine rich heptapeptide region. Giza/2000 showed two additional unique a.a residues at positions 220Phe and 321Thr that resulted from two unique nucleotide substitution at positions 609(ATO t) and9111 (G to a). Surprisingly Giza/2000 shared the unique a.a residue at position 254 (Gly to Ser)with the American Var A.Del/E and GLS. Giza/2000 isolate showed 9 nucleotide differences with 3 a.a substitution at positions 220Phe, 254Ser and 321Thr from the Egyptian isolate at 1989 (K406/89) giving indication that circulating IBD viruses in Egypt still undergoing mutations.
Publication year 2004
Pages 405-420
Availability location معهد بحوث الامصال واللقاحات البيطرية
Availability number
Organization Name
serial title Egyptian J of virology
Author(s) from ARC
External authors (outside ARC)
    داليا عبد المعطي معهد بحوث الأمصال واللقاحات البيطرية
Agris Categories Animal diseases
AGROVOC
TERMS		 Infectious bursal disease virus. Molecular genetics.
Proposed Agrovoc hyper variable region;
Publication Type Journal
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