Molecular characterization of recent Iranian infectious bronchitis virus isolates based on S2 protein gene

Abstract

<strong>Background:</strong> Avian infectious bronchitis (IB), with avian<br />infectious bronchitis virus (IBV) as the causing agent, is a ubiquitous endemic<br />disease of the chicken with devastating effects on its industry. A viral<br />membrane surface protein called S not<br />only induces neutralizing antibodies but also plays an important role in virus<br />binding and entry to host cells. Technically, S1 protein gene sequencing also<br />helps greatly in IBV genotyping. <strong>OBJECTIVES:</strong> The aim of this study was<br />to characterize Iranian IBV based on S2 gene. <strong>METHODS:</strong> After RT-PCR<br />amplification, the S2 gene of nine Iranian IBV isolates were sequenced and then<br />compared with reference strains. <strong>RESULTS: </strong>The isolates were classified<br />into genotype I as Massachusetts like IB Vs, genotype VII which clustered into<br />two branches, VIIa (IS-1494 like IB viruses), and VIIb, and was related to QX-<br />like viruses and Genotype VIII as 793/B like IBVs. <strong>CONCLUSIONS:</strong> As far<br />as we know, this is the first S2-based classification study on Iranian IBV<br />isolates providing a firm experimental basis to correlate with genotypic<br />characterization