National Institute of Animal Health (NIAH)

Topics in Animal Health Research 1996

12. Escape mechanism of Mycobacterium paratuberculosis from bovine intestinal tissue


Mycobacterium paratuberculosis causes bovine paratuberculosis that is characterized by chronic granulomatous enteritis, diarrhea and emaciation. Bacterial isolation from fecal sample is a reliable diagnostic method in the anergic state. Over 1012 bacteria/day are shed in feces in the clinical stage. However, there was no evidence of the shedding mechanism of the bacteria in the granulomas to intestinal lumen, through the mucosal epithelial varrier. We reported a novel passive shedding mechanism by using host macrophages that treat apoptotic epithelial cells in constant epithelial renewal. We have previously reported the passive entrance by M-cell. These results strongly emphasize the impression of the successful bacteria that invade and escape passively by using the host's phisiological function without any damage.
(Lab. of Molecular Pathology, Department of Immunology)