Bacteria: Mycobacterium avium ssp. paratuberculosis

Johne's disease (JD), also known as paratuberculosis, is a chronic disease of ruminants caused by Mycobacterium avium subspecies paratuberculosis (MAP or M. paratuberculosis ). Clinical symptoms tend to appear within 2–5 years of the animal's life. Clinically and subclinically infected animals shed MAP in their feces and milk, and thus are effective contaminators of the environment and spread the infection to neighboring animals including offspring. These latter derive their infections mainly through ingestion of colostrum, milk, and feedstuffs containing MAP, although intrauterine transmission has also been documented. There is widespread exposure of MAP to the human population and Crohn's disease has been associated with this exposure. This disease is a chronic inflammation of the intestine, similar to JD in cattle.