Isolation and molecular characterization of infectious bronchitis virus, isolate Shiraz 3. IBV, by RT-PCR and restriction enzyme analysis

ABSTRACT

Infectious bronchitis virus [IBV] strain 4/91, prototype of the 793/B serogroup, was recently reported from Khouzestan province, Iran. Here we isolated and molecularly characterized a virus [Shiraz3. IBV] from broilers in Fars province. Following virus propagation in embryonated chicken eggs, we extracted total RNA containing the viral RNA from allantoic fluid. cDNA of the entire SI and nucleocapsid [N] genes were generated with AMV-reverse transcriptase and genomic specific primers. The cDNA was subsequently amplified in a polymerase chain reaction [PCR]. Digestion of the PCR products representing the entire SI gene generated restriction fragments identical to those expected from strain 4/91 and differed from the control vaccine strain of H120. The N RT-PCR products representing the entire N genes of strains Shiraz3. IBV and H120 did not show any visible difference in size. The results presented here demonstrated that isolate Shiraz3. IBV is genetically closely related to strain 4/91 of IBV and can be differentiated from the IBV vaccine strain in Iran