Identification of Mycobacterium avium ss. paratuberculosis in Crohn's Tissue

I.Shafran, C. Piromalli, C.Romero, D.Schwartz and S.Naser

Background: Mycobacterium ss. paratuberculosis (MAP) is known to cause chronic granulomatous enteritis in ruminants and primates (Johne s Disease). Many groups have implicated the possible role of the spheroplastic form of MAP in Crohn’s Disease (CD) but the isolation and identification of this bacteria have been difficult due to the uncertain location and rigid growth requirements of this organism. Purpose: To investigate the role of MAP in CD using short-term mycobacterial culture media. Methods: 27 CD tissue specimens (7 surgical resected tissue and 20 biopsies) and 36 controls (3 surgical resected tissue and 33 biopsies) were processed and cultured in both 12B* Bactec bottles and Mycobacterial Growth Indicator Tubes (MGIT) with OADC enrichment, Mycobactin J and PANTA antibiotic mixture for up to one year. Bacterial detection and identification was done through Acid fast staining, mycobactin dependency, PCR analysis using two IS900-derived oligonucleotides and hybridization with an internal probe. Results: Microbial growth was found in both culture media, although only MGIT cultures contained MAP. MAP bacterial isolates were confirmed to be acid fast bacilli, mycobactin dependent and positive for the presence of IS900 and hybridization. Presence of MAP in MGIT cultures were detected in 12 weeks of incubation for resected tissue and 40 weeks for biopsies. See table for results. Conclusion:  MAP was much more readily found in CD specimens as compared to control specimens. Additionally, MAP was found more readily in resected tissue and required short-term incubation in contrast to endoscopic biopsies. This may indicate that MAP resides submucosally. Our findings suggest that surgical resected tissue cultured in MGIT media is favorable for the rapid cultivation of MAP versus endoscopically acquired biopsies.

MAP Culture Results From CD and Conrtol Tissue

All content copyright ©1999 Dr. Ira Shafran, M.D.

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