Absence of Mycobacterium avium subspecies paratuberculosis components from Crohn's disease intestinal biopsy tissues.
BACKGROUND
Crohn's disease is a chronic human intestinal inflammatory disorder for which an etiologic agent has not been identified. Johne's disease is a similar chronic enteric granulomatous disease of ruminant species and has been used as a model of Crohn's disease. Johne's disease has been proven to be caused by Mycobacterium avium subspecies paratuberculosis (M. avium ss paratuberculosis). It has been proposed that M. avium ss paratuberculosis may also cause Crohn's disease. This is of particular concern because the organism may be spread to humans through inadequately pasteurized dairy products.


OBJECTIVE
We sought to determine whether M. avium ss paratuberculosis could be detected using identical techniques in paraffin-embedded tissue samples of bovine Johne's disease and human Crohn's, ulcerative colitis and diverticular diseases. Samples were obtained for analysis from national tissue banks.


METHODS
Cross-species and cross-disease sample comparisons by multiple detection techniques.


METHODS
Histology, immunocytochemistry and polymerase chain reaction (PCR) were utilized to test and compare the presence of M. avium ss paratuberculosis components. Insertion sequence IS900, present in multiple copies and found only in M. avium ss paratuberculosis, was utilized in both PCR and immunocytochemical analyses.


RESULTS
The IS900 sequence was demonstrable in all samples of confirmed positive Johne's disease tissue. The sequence was not identified in the 35 Crohn's, 36 ulcerative colitis, and 21 diverticular disease samples.


CONCLUSIONS
M. avium ss paratuberculosis was not associated with the lesions in these Crohn's disease samples, using these methods.
Ellingson
Jay L E
JL
Department of Veterinary Pathology, College of Veterinary Medicine, Iowa State University, Ames, Iowa, USA. ellingson.jay@marshfieldclinic.org
Cheville
John C
JC
Brees
Dominique
D
Miller
Janice M
JM
Cheville
Norman F
NF
D001706:Biopsy; D003424:Crohn Disease / Q000382:microbiology* / Q000473:pathology*; D004269:DNA, Bacterial / Q000032:analysis; D006801:Humans; D007150:Immunohistochemistry; D007422:Intestines / Q000382:microbiology / Q000473:pathology; D016927:Mycobacterium avium subsp. paratuberculosis / Q000235:genetics / Q000302:isolation & purification*; D010283:Paratuberculosis / Q000473:pathology*; D012189:Retrospective Studies
D004269:DNA, Bacterial