Molecular genotyping of infectious bursal disease virus (IBDV)‎ isolated from layer flocks in Iraq

الملخص EN

Recently highly pathogenic strains of IBDV have been appeared causing great economic losses.

In this research IBDV has been isolated in Iraq successfully from seven samples from different Layer flocks (32 field) in different Iraqi provinces.

Bursa of fabricia samples were assessed using reverse transcriptase-polymerase chain reaction (RT-PCR) for the presence of IBDV adoption VP2 gene.

All seven tested samples were positive.

Rapid test was conducted for the all samples to identify positive cases of IBD.

Seven positive samples were selected to isolate IBDV showed 350bp by the use of conventional RT-PCR technique as assurance to the presence of IBDV.

Histological sections of the bursa of fabricia showed the presence of necrosis, depletion of the follicles and the some hetrophil infiltration, these features were consider pathognomic for IBDV infection.

The virus has been isolated by injected bursal suspension in embryonated chicken eggs.

CAM has been collected and examined by AGPT to confirm the existence of IBDV.

After confirming the presence of the virus by RT-PCR sequence analysis by application of PCR products for the seven samples.

All seven selected samples very virulent vvIBDV.

Genotyping of Iraqi vvIBDV strains showed a gradual evolution of the IBDV in Iraq, where they were not closely linked to the previous isolated Iraqi strains