Mycobacterium avium is the causative agent of avian tuberculosis. It is an aerobic, non spore-forming, rod shaped bacteria that are weakly Gram-positive.
Survival in the Environment: M. avium is frequently found throughout the environment, especially soil. It is highly resistant to environmental challenges and can survive in the soil for up to 4 years. The organism is resistant to high and low temperatures, dryness, pH changes, and many commonly used disinfectants. However, the unprotected organism is killed by direct sunlight.
Hosts: Wild birds, pigs, and some mammals may also act as significant reservoirs of infection, and spread M. avium to backyard poultry flocks. Rodents such as mice and rats have also been known to act as mechanical carriers, and transmit the disease to poultry flocks.