Original Research Absence of Mycobacterium avium subspecies paratuberculosis Components from Crohn’s Disease Intestinal Biopsy Tissues

BACKGROUND Crohn’s disease is a chronic human intestinal inflammatory disorder for which an etiologic agent has not been identified. Johne’s disease is a similar chronic enteric granulomatous disease of ruminant species and has been used as a model of Crohn’s disease. Johne’s disease has been proven to be caused by Mycobacterium avium subspecies paratuberculosis (M. avium ss paratuberculosis). It has been proposed that M. avium ss paratuberculosis may also cause Crohn’s disease. This is of particular concern because the organism may be spread to humans through inadequately pasteurized dairy products. OBJECTIVE We sought to determine whether M. avium ss paratuberculosis could be detected using identical techniques in paraffin-embedded tissue samples of bovine Johne’s disease and human Crohn’s, ulcerative colitis and diverticular diseases. Samples were obtained for analysis from national tissue banks. DESIGN Cross-species and cross-disease sample comparisons by multiple detection techniques