DESIGNING OF NOVEL SPECIFIC RT-PCR FOR DETECTION OF 793/B GENOTYPE OF AVIAN INFECTIOUS BRONCHITIS VIRUS

Background and Aim:Avian Infectious Bronchitis is a severely contagious, acute viral respiratory disease of chickens caused by infectious bronchitis virus (IBV), which leads to substantial economic losses in the poultry industry. So far, many serotypes have been detected but Massachusetts and 793/B are among the most important and prevalent serotypes of IBV worldwide. The S gene of IBV carries virus-neutralizing, serotype-specific, and genotyping determinants.Methods:RNA of virus has been isolated from chicken by respiratory clinical sign and commercial 4/91 vaccine. A set of primer was designed based on sequences in the Gene Bank for amplified Spike gene. The sensitivity of the RT-PCR primers was established by different amount IBV strains. To evaluate the specificity of the method, the following RNA viruses were used NDV and AI and other IBV strains. RT-PCR product was sent to sequence.Results:To carry out IBV of 793/B was achieved by using primers specific for this types (S gene) in two-step RT-PCR. Product size was ~200 bp. The specificity pairs of each specific primers were examined by another genotype. Pairs of each specific primers identified specific genotypes. The samples were confirmed by de-deoxi Sanger sequencing.Conclusion:IBV has a significant effect in poultry industry including drops in egg production, poor eggshell quality, drops in hatchability, nephritis, sometimes false layers, poor weight gain and feed efficiency in commercial broiler. Currently, 793/B type viruses have been detected in several other Asian countries, including IRAN. So it was needed to detect this strain with a quick and accurate test in the flocks.

کلیدواژه ها:

Infectious bronchitis virus (IBV) ، 793/B ، RT-PCR