آلودگي طبيعي ناشي از ORNITHOBACTERIUM RHINOTRACHEALE در گله هاي طيور تجاري و عفونت تجربي آن در جوجه هاي عاري از پاتوژنهاي اختصاصي

Natural infection with Ornithobacterium rhinotracheale in Commercial poultry and experimental infection in specific -pathogen - free chickens

In 2000 and early 2001 , samples from 120 poultry farms submitted to Razi Institute were examined for Ornithobacterium rhinotracheale (ORT) isolation. Ninty six farms out of these 120 farms (80%) had respiratory disorders, which 57 farms of them (59.4%) were infected with ORT, and all the infected flocks showed respiratory signs. Prominent signs in the infected flocks were airsacculitis, tracheitis, purulent cast near to syrinx, bronchopneumonia and sinusitis. Right ventricular failure (RVF) or ascites during or after course of ornithobacteriosis were seen. Out of 20 tarms with high mortality and respiratory disorders, 16 farms (80%) were infected with ORT.In this study ornithobacteriosis was observed in various types of commercial chicken including broilers, layers, and broiler breeders. Field isolates of ORT from natural Ornithobacteriosis submitted to Razi Institute were tested on their pathogenicity in specific-pathogen-free (SPF) chickens. ORT isolates were found to cause airsacculitis, tracheitis, pneumonia and pericarditis in 2-month-old SPF chickens, after intra - tracheal administration, and to cause sinusitis after intra - sinus injection. ORT was reisolated from affected organs, and all SPF chickens inoculated with ORT developed antibodies to ORT detectable by the serum plate agglutination test. Upon the results ORT can be recognized as an important cause of losses in poultry industry of our country.