Mycobacteria in the intestine of Japanese patients with inflammatory bowel disease.

Abstract

It is still controversial whether or not a mycobacterial infection may be a cause of Crohn's disease. Mycobacterium paratuberculosis may be very difficult to detect using routine culture techniques. To clarify this, we detected mycobacterial DNA in patients with inflammatory bowel disease. IS900 sequences highly specific to M. paratuberculosis and the groEL gene encoding a conserved mycobacterial antigen were studied in colonic mucosa using polymerase chain reaction (PCR). PCR products were analyzed by Southern blot hybridization. IS900 sequences were detected in all (100%) of 10 patients with Crohn's disease, in 11 (61.1%) of 18 patients with ulcerative colitis, and in 14 (87.5%) of 16 control patients with noninflammatory bowel disease. All IS900 positive samples had groEL PCR products. Our results, on the basis of the prevalence, do not support the hypothesis that M. paratuberculosis is involved in the pathogenesis of Crohn's disease.