Comparative Analysis of Highly Virulent Infectious Bursal Disease Viruses Isolated in Turkey Using the SDS-PAGE and Western Immunoblotting Techniques

Authors: Olcay TÜRE, Fethiye ÇÖVEN

Abstract: Structural protein profiles and antigenic ralatedness of the regional viruses (Agean:G34, G35; Marmara:G41; Central Anatolia:ETL3) isolated from the infectious bursal disease outbreaks in Turkey were examined comparatively with the serotype 1 classic (D78) and variant (E variant) strains using the SDS-PAGE (Sodium Dodecyl Sulphate Polyacrylamide Gel Electrophoresis) and Western immunoblotting techniques. SDS-PAGE analysis of 3 purified field (G34, G35, ETL3) and 1 reference (D78) viruses showed that local viruses had the same protein profiles with the serotype 1 reference strain. VP2(40K), VP3(32K) and VPX(48K) were the proteins identified in Coomassie blue stained gels. In this study, it was not possible to detect the other structural proteins (VP1 and VP4) clearly due to the cellular contaminant proteins. The polyclonal antisera to D78, E variant, G34, G35, G41 and the ETL3 strains used in Western immunoblotting tests detected mostly three protein bands, VP2, VP3 and a 52K molecular weight protein which was reported to be the precursor of VP3 in homologous and heterologous reactions. The antisera to ETL3 showed stronger reaction with VP2 of the viruses comparison to the VP3. The antisera to G35 strain reacted only with the VP3 and its precursor protein and showed no detectable reaction with the VP2 protein. In conclusion, no differences were found between the reference and the regional IBDV strains in terms of protein profiles as detected by SDS-PAGE. Western immunoblotting studies indicated that, although some differences were observed in case of ETL3 and G35 reactions, the majority of viruses tested in this study were antigenically similar.

Keywords: Highly Virulent IBDV, Proteins, Antigenic Characterization, SDS-PAGE, Western Immunoblotting.

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