Detection of Infectious Bronchitis Virus (4/91 type) in Broiler Chickens in Chahrmahal-va-bakhtiyari Province

Infectious bronchitis (IB) disease is a viral contagious respiratory disease. The causing agent of this disease has several serotypes. In this study, 4/91 type of Infectious bronchitis (IB) was identified. For this, tracheal samples were taken from 18 broiler chickens flocks having respiratory signs suspected to IB disease with one percent mortality in day. After RNA extraction from tissue samples in one step RT-PCR reaction, a fragment of S1 gene was amplified by common primers for all IB viruses. Then RT-PCR product was amplified for identification of 4/91(793/B) type by type specific primers in Nested-PCR. Results showed, 11 out 18 flocks (61.1%) were infected to IB that 45.45% of IB infected flocks were infected to 4/91 type. Therefore it seems 4/91 type of IB has role in forming and complexing of respiratory signs in broiler chickens suffering to respiratory syndrome in Chahrmahal-va-bakhtiyari province and it is necessary to give a suitable controlling strategy for prevention of 4/91 infection.