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Background and Aim: Infectious Bursal Disease (IBD) is a highly infectious
disease which causes huge economic losses to the poultry industry due to
the direct impact of the illness and indirect consequences such as
decreasing the general immunity of the flock, leaving it naive to other
diseases. In Iraq, IBD is highly prevalent despite vaccination programs,
yet studies on sequence diversity of the causative virus are still rare.
Methods: A sample from Bursa of Fabricius from an IBD outbreak in a flock
in the city of Najaf in Iraq was smeared on an FTA card. Amplicons of
targeted regions in VP1 and VP2 genes were generated and sequenced.
Sequences were then compared with other local and global sequences
downloaded from GenBank repositories. Sequence alignment and DNA sequence
analyses were achieved using MUSCLE, UGENE and MEGAx software. The
molecular clock and sequence evolutionary analyses were applied using
MEGAx tools. Results: The strain sequenced in this study belongs to a very
virulent Infectious Bursal Disease Virus (vvIBDV) as the DNA and
phylogenetic analysis of VP1 and VP2 gene sequences showed a mutual
clustering with similar sequences belonging to vvIBDV genogroup 3.
Analyses of the hyper variable region of VP2 gene (hvVP2) of IBDV isolates
from Iraq indicates a presence of sequence diversity. Interestingly, the
two vaccine strains Ventri IBDV Plus and ABIC MB71 that showed the highest
sequence similarity to the local isolates in the hvVP2 region are not used
in vaccination routine against IBDV in Iraq. Conclusion: Sequences of
vvIBDV in Iraq are diverse. Remarkably, some of the available vaccine
strains show high sequence similarity with local strains in Iraq; however,
they are not included in the routine vaccination programs. Analysis of
more samples involving more geographical regions is needed to draw a
detailed map of antigenic diversity of IBDV in Iraq. Please ensure that
the sequence data has been uploaded to a structured repository, e.g.
NCBI/ENA. Details can then be included in the data availability statement
after the conclusion. Please include details in the Software availability
statement. I have added the format for you at the end of this paper.
174 views reported since publication in 2021.