Search for Mycobacterium paratuberculosis DNA inorofacial granulomatosis and oral Crohns disease tissue by polymerasechain reaction

摘要

Background—Although intestinal Crohn's disease has long been suspected to have a mycobacterial cause, possible mycobacterial involvement in orofacial granulomatosis (OFG) and oral lesions of Crohn's disease has not yet been investigated.
Aims—As the slow growing Mycobacterium paratuberculosis has been implicated in the aetiology of intestinal Crohn's disease, the potential involvement of this mycobacterial species in OFG and oral lesions of Crohn's disease was investigated.
Patients—To attempt detection of the organism in OFG and oral Crohn's disease tissue samples, a polymerase chain reaction (PCR) assay was used on archival formalin fixed, paraffin wax embedded oral tissue sections from 30 patients with OFG, seven with Crohn's disease, and 12 normal controls.
Methods—The PCR assay used was based on primers targeting the 5' region of the multicopy IS900 DNA insertion element of the M paratuberculosis genome. In order to achieve maximum sensitivity, two rounds of PCR were carried out and amplicons confirmed by Southern blot hybridisation to adigoxigenin labelled IS900 DNA probe.
Results—None of the OFG andoral lesions of Crohn's disease samples were positive forM paratuberculosis and all normal controls were also negative.
Conclusions—These results suggestthat M paratuberculosis may not be a major aetiologicalagent in OFG or oral Crohn's disease lesions, although the use ofparaffin wax embedded tissue as opposed to fresh tissue as a samplesource could underestimate the true prevalence of the organism.

Keywords:oral Crohn's disease; Mycobacteriumparatuberculosis; orofacial granulomatosis; polymerase chainreaction