author(s)
Smita Bordoloi, Anju Nayak, Joycee Jogi, Poonam Shakya, Ajay Rai and Shivangi Sharma

abstract
Respiratory infections are the common causes for mortality and morbidity in poultry, which leads to huge economic losses to the poultry indrustry. Ornithobacterium rhinotracheale, is the emerging pathogen and difficult respiratory tract bacteria to isolate and grow in the laboratory. The first report of isolation O. rhinotracheale was in 1981 from the respiratory tract of 5 weeks old turkeys with fibrinopurulent airsacculitis and the characterization was done in 1993. The bacterium can be grown on 5-10% sheep blood agar and does not grow on MacConkey agar and Simmons citrate medium. It grows aerobically, micro aerobically and anaerobically, but the best growth occurs in air enriched with 7.5 to 10 % CO_2. Microscopically, Gram-negative, non-motile, highly pleomorphic, rod-shaped and non-sporulating bacterium. It spreads horizontally by direct and indirect contact through aerosol or drinking water. The outbreaks are inconsistent and can be influenced by a wide range of environmental factors. Symptoms characterized by mild respiratory signs, nasal discharge, swollen sinus, slightly increased mortality and poor performance specially in chicks.