Absence of Mycobacterium avium ss paratuberculosis-specific IS900 sequence in intestinal biopsy tissues of Indian patients with Crohn's disease

Abstract

Background and objective: The role of Mycobacterium avium ss paratuberculosis (MAP) in the etiopathology of Crohn's disease (CD) remains controversial, because of conflicting reports demonstrating the presence of MAP-specific insertion sequence from intestinal biopsy tissues of patients clinically diagnosed for the disease. The present study was carried out to investigate the presence of MAP DNA in the intestinal tissues of CD patients to ascertain the relevance of MAP in Indian patients with CD.

Methods: Patients diagnosed as CD at our institute were recruited. Healthy individuals without inflammatory bowel disease served as controls. Mucosal biopsy specimens were collected from ileum and colon in duplicates and subjected to histopathological examination and polymerase chain reaction (PCR) amplification. Total DNA (81 CD patients, 85 healthy individuals) and total RNA (12 CD patients, 12 healthy individuals) isolated from tissue specimens was used for amplification of MAP-specific IS900 by nested PCR.

Results: MAP-specific IS900 DNA and RNA could not be detected by nested PCR in the intestinal tissues of any patient with CD.

Conclusion: Our results do not support the etiological role of MAP in the pathogenesis of CD in Indian patients.