High prevalence of viableMycobacterium aviumsubspeciesparatuberculosisin Crohn’s disease

Abstract

To examine the detection rate of viable Mycobacterium avium subspecies paratuberculosis (MAP) in patients with inflammatory bowel disease [Crohn's disease (CD) and ulcerative colitis (UC)]. Thirty patients with CD (15 with at least one NOD2/CARD15 mutation), 29 with UC, and 10 with no inflammatory bowel disease (IBD). were tested for MAP by polymerase chain reaction (specific IS900 fragment) and blood culture. MAP DNA was detected in all original blood samples and 8-wk blood cultures (CD, UC and non-IBD). Positive MAP DNA status was confirmed by dot blot assays. All 69 cultures were negative by acid-fast Ziehl-Neelsen staining. Viable MAP, in spheroplast form, was isolated from the 18-mo blood cultures of all 30 CD patients, one UC patient, and none of the non-IBD controls. No association was found between positive MAP cultures and use of immunosuppressive drugs or CD-associated single nucleotide polymorphisms. MAP is widely present in our area and MAP DNA can be recovered from the blood of CD, UC and non-IBD patients. However, MAP spheroplasts were only found in CD patients.