Diagnosis of Ornithobacterium rhinotracheale infection in chickens by ELISA.

Specific Ornithobacterium rhinotracheale (ORT) antibodies were determined in serum samples of 24 clinically infected broiler flocks of different ages (1-42 d) and 11 broiler-breeding flocks (at ages between 26-56 w) by ELISA. Two commercially available kits were separately assessed. The BioCheck ELISA kit was used for testing 363 serum samples representing 12 broiler flocks, where 74 samples (20.3 %) were found to be positive and 49 (13.5 %) were suspected. The IDEXX ELISA kit was used for testing 148 serum samples representing different 12 broiler flocks, where 115 samples (77.7 %) were positive. Testing of additional 70 serum samples from 5 broiler- breeder flocks, associated with drop in egg production (1-4.5 %) at different ages, by BioCheck ELISA kit revealed that 78.5 % of the samples were positive and 21.4% were suspected. On the other hand, 338 serum samples representing 6 broiler-breeder flocks, associated also with egg drop, showed a 84.6 % rate of positive reaction, when tested by IDEXX ELISA kit. Positive serology correlated well with the clinical manifestations and isolation of the organism, which substantiates the reliability of the used kits in diagnosis of the disease.