Comparative ELISA and SAT assays in detection of Ornithobacterium rhinotracheale antibodies in broiler chickens at Sharkia Governorate

The Ornithobacterium rhinotracheale (ORT) has been involved in respiratory disease complex in poultry. In a trial to investigate the inclusion of ORT in broiler chickens suffering from respiratory troubles two hundred and fifty birds ( 30 flocks) were subjected to clinical, PM and serological examination . The clinical findings of the examined birds were nasal discharges, rales, swollen eyes accompanied by diarrhea in some cases. Fibrinous pericarditis, perihepatitis and air sacculitis as well as caseated materials in trachea and bronchi were the frequently associated gross lesions beside foamy yoghurt like exudates. Enzyme linked immunosorbant assay (ELISA) was applied on Sera samples (N= 250) to detect antibodies against ORT. ELISA results were positive among 80% of the tested flocks .A selected 49 sera samples were submitted for both ELISA and Slide agglutination test (SAT). Their outcomes revealed 93.9% positive for ELISA and 89.8% and 69.38% against ORT-I and ORT-II antigens respectively. The comparable findings proved that in case of unavailability of ELISA assay the SAT could be helpful alternative in ORT antibody monitoring.