Phylogenetic analysis and full-length characterization of S1 gene of IS-1494 (Variant 2) like infectious bronchitis virus isolates, Iran, 2015

Infectious bronchitis virus (IBV), a major pathogen of commercial poultry flocks, circulates in the form of different genotypes. Three IB viruses were isolated from broiler chickens showing respiratory and renal lesions. The isolates were characterized by reverse transcriptase polymerase chain reaction and sequence analysis of the Full-length of the S1. Three isolates were belonged to Variant 2 like (IS/1494 like) IBV genotype. Phylogenetic analysis showed that Variant 2 like isolates formed two clusters and the Iranian and Iraqi isolates were included in the cluster II. Cluster I composed of Israeli, Egyptian and Turkish Variant 2 like IBV Isolates. Three hyper variable regions (HVR) of S1 were determined. The Most variation was seen in HVR2. The findings emphasize the importance of continuous monitoring of IBV, in addition to adjust diagnostic methods, molecular epidemiological studies, development and use of vaccines which are adapted to the changing disease scenario.