ISOLATION AND IDENTIFICATION OF INFECTIOUS BRONCHITIS VIRUS AND EXPERIMENTAL INFECTION IN BROILERS

Abstract

Poultry in iraq especially broilers showed high percentage of mortality, some of them reached (70%), with severe respiratory signs, depreassion and loss of body weight. Also nephritis with urolethiasis. Infectious bronchitis virus (IBV) was the suspected infections agent. So that, this study was conducted to diagnose IBV in broilers through estimation of IBV antibody by Enzyme Linked Immunosorbent Assay (ELISA) technique through collecting blood samples from infected farms and isolate the virus using one step real time RT-PCR and chicken embryo fibroblast tissue culture (CEF). The isolated IB virus was used to carry on an experimental infection in broiler chicks. Lung, trachea and kidney samples were collected for histopathological study. ELISA results showed very high titers of IBV antibodies after (14) day post clinical signs appearance. rRT- PCR results were positive for the samples (trachea, lung and kidney) collected in the beginning of the disease. Tissue culture results showed pathological tissue changes after inoculation with the isolated virus. Twenty broiler chicks were used for experimental infection on day (22). Clinical signs appeared (36 hr) post infection with (32%) mortality and histopathological changes characterized by lymphocytic infiltration and congestion in trachea, lung and kidney.