Authors: Bull TJ, McMinn EJ, Sidi-Boumedine K, Skull A, Durkin D, Neild P, Rhodes G, Pickup R, Hermon-Taylor J.

Institution: Department of Surgery, St. George's Hospital Medical School, London SW17 0RE, United Kingdom.

Summary: Mycobacterium avium subsp. paratuberculosis is a robust and phenotypically versatile pathogen which causes chronic inflammation of the intestine in many species, including primates. M. avium subsp. paratuberculosis infection is widespread in domestic livestock and is present in retail pasteurized cows' milk in the United Kingdom and, potentially, elsewhere. Water supplies are also at risk. The involvement of M. avium subsp. paratuberculosis in Crohn's disease (CD) in humans has been uncertain because of the substantial difficulties in detecting this pathogen.

In its Ziehl-Neelsen staining-negative form, M. avium subsp. paratuberculosis is highly resistant to chemical and enzymatic lysis. The present study describes the development of optimized sample processing and DNA extraction procedures with fresh human intestinal mucosal biopsy specimens which ensure access to M. avium subsp. paratuberculosis DNA and maximize detection of these low-abundance pathogens.

…In each case the identity of IS900 from M. avium subsp. paratuberculosis was verified by amplicon sequencing. The rate of detection of M. avium subsp. paratuberculosis in individuals with CD is highly significant and implicates this chronic enteric pathogen in disease causation.

Study link: http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=12843021&query_hl=13

• Detection and Verification of Mycobacterium Avium Subsp. Paratuberculosis in Fresh Ileocolonic Mucosal Biopsy Specimens from Individuals With and Without Crohn's Disease
• Culture of Mycobacterium Avium Subspecies Paratuberculosis from the Blood of Patients with Crohn's Disease
• High Prevalence of Mycobacterium Avium subspecies Paratuberculosis IS900 DNA in Gut Tissues from Individuals with Crohn's Disease
• Evaluation of Surgical Tissue from Patients with Crohn's Disease for the Presence of Mycobacterium Avium subspecies Paratuberculosis DNA by in situ Hybridization and Nested Polymerase Chain Reaction