[Mycobacterium paratuberculosis in the intestine of patients with Crohn's disease].

Crohn's disease has long been suspected of having a mycobacteria, specifically M. paratuberculosis cause. In this study polymerase chain reaction (PCR) assay was used to detect M. paratuberculosis DNA in 74 paraffin wax embedded gut tissues from endoscopic biopsy or surgical resection specimens, including 36 Crohn's disease tissues, 18 ulcerative colitis tissues and 20 non-inflammatory bowel disease tissues. Oligonucleotides derived from IS900 sequence, which is a repeated in M. paratuberculosis chromosome and highly specific for the M. paratuberculosis, were used as primer. The specificity of products was confirmed by southern blot hybridization by using a biotin-labeled probe. The results show that M. paratuberculosis DNA was detected in 17 Crohn's disease (47.2%), 2 ulcerative colitis (11.1%) and 3 non-inflammatory bowel disease control subjects (15.0%). PCR positive or negative results in 36 Crohn's disease show that there is no relation with small or large gut involvement, and also the presence or absence of granulomata. The results suggest that M. paratuberculosis is surely present in tissues from some patients with Crohn's disease, which may have a specific association with Crohn's disease.