Novel RFLP Method for Detection of Four Avian Infectious Bronchitis Virus Genotypes (Massachusetts, 793/B, Variant2, and QX

Infectious bronchitis (IB) is one of the significant economically critical poultry diseases distributed worldwide, including Iran. Different IB virus (IBV) genotypes are circulating in different geographical regions. Typing of IBV strains is useful for implementation of control measures and for understanding the epidemiology and evolution of IBV. The S1 gene sequencing is used for IBV genotyping. Massachusetts, 793/B, QX, and IS-14194 IBV genotypes currently exist in Iranian poultry farms. This study aims to design an RFLP-based method to do genotyping and confirm of mentioned IBV genotypes. Materials and Methods: After amplification of parts of the S1 gene (RT-PCR), the PCR products treated with four enzymes (SfoI: Massachusetts, BtsCI: 793/B, MspI: IS-1494, and NruI: QX) and finally visualized on agarose gel electrophoresis. Results: Results showed 100 percent of the specificity of the newly designed method (in comparison with sequencing). Conclusions: This method can be used for primary confirmation and fast screening of Massachusetts, 793/B, QX, and IS-14194 IBV genotypes and even in local laboratories without the need for sequencing.