Molecular characterization and phylogenetic analysis of infectious bursal disease virus (IBDV)‎ isolated from broiler chicken in Kafrelsheikh Governorate, Egypt 2013

الملخص EN

IBDV is still one of the most important causes of significant economic losses in poultry industry in Egypt, although implementation of the intensive vaccination programs.

A recent increase in IBDV related mortality in vaccinated chicken broiler farms in kafrelsheikh governorate, prompted to investigate the molecular characters of the circulating IBDV.

In present study, bursa samples were collected from infected flocks; the virus was isolated by inoculating bursa suspension into embryonated specific pathogen-free (SPF) eggs.

Chorioallantoic membrane(s) (CAMs) were collected and tested using reverse transcriptase-polymerase chain reaction (RT-PCR) for IBDV targeting VP2 gene.

Eight IBDV- samples showed 620 bp of VP2 gene gave a positive amplicon.

A phylogenetic tree was constructed in order to compare and analyze the genetic relationships of the IBDV isolates derived from Kafrelsheikh governorate, Egypt and different isolates from other countries.

The phylogenetic tree revealed that six samples were characterized as very virulent (vvIBDV) and closely related to the Egyptian Isolates of vvIBDV (SV-G1, SV-G4, SV-G5, Beh2003 and Giza2008) while, two samples showed close relationship with the Bursa-Vac vaccinal strain.