Mycobacterium paratuberculosis and Crohn's disease.

Mycobacterium paratuberculosis is the causative agent of Johne's disease, a chronic enteritis in ruminants. It has been suggested that Crohn's disease, a gastrointestinal disease in humans with similar clinical symptoms and histopathological findings, is caused by the same bacteria. Epidemiological data support Crohn's disease possibly being caused by an infectious agent. Recently, with improved culture techniques and the advent of polymerase chain reaction, M. paratuberculosis has been identified from tissues of increasing numbers of patients with Crohn's disease. However, conflicting data still occur and the case for M. paratuberculosis as the etiological agent of Crohn's disease can be neither proved nor disproved. The development of new diagnostic tests and comprehensive well-defined clinical studies will hopefully provide us with information about this association in the future.