Absence of mycobacterium avium subsp. paratuberculosis in Crohn's patients.

Background: Mycobacterium avium subspecies paratuberculosis (MAP) has been suspected of involvement in Crohn's disease (CD). We investigated this potential association by testing whole blood from CD patients and healthy controls for the presence of MAP by culture and molecular methods. In addition, each blood sample was analyzed for polymorphisms in the NOD2/CARD15 gene previously associated with CD.

Design and development of an internal control plasmid for the detection of Mycobacterium avium subsp. paratuberculosis using real-time PCR.

Mycobacterium avium subspecies paratuberculosis (MAP) is the etiological agent of Johne's disease in ruminants. The hspX gene and insertion sequence IS900 can be used to diagnose Johne's with PCR. Generally, a single PCR tube containing the DNA sequence of interest is run as a positive control with each set of reactions.