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Attachment of Mycobacterium avium subspecies paratuberculosis to bovine intestinal organ cultures: method development
Patricia M Schleig1, Claus D Buergelt, Jerry K Davis
1Department of Pathobiology, University of Florida College of Veterinary Medicine, P.O. Box 110880, Gainesville, FL 35211, USA.
Abstract:
Mycobacterium avium spp. paratuberculosis (MAP) causes chronic granulomatous inflammation of the intestinal tract in many species of animals, but the mechanisms of disease are poorly understood. Attachment of bacteria to epithelial cells is a critical step in pathogenesis of many mucosal diseases. The goal of these studies was to develop an in vitro method to study attachment of MAP to bovine intestinal epithelial cells. Short-term, bovine intestinal organ cultures were used to show a significant difference in the ability of radiolabelled MAP strains to attach to intestinal epithelium. We found significant differences in the ability of different strains of MAP to attach, but there were no differences in attachment among different regions of the intestinal tract. Examination of acid fast stained tissue sections of organ cultures demonstrated that organisms were located adjacent to mucosal epithelium or within goblet cells. Coating of the organisms with fibronectin, which has been shown to be involved in attachment of many mycobacteria, including MAP, affected the attachment of the MAP strains in different ways, but did not affect the overall attachment of the organisms to different regions of the gastrointestinal tract. This organ culture method should also prove useful for defining the molecular mechanisms of attachment and interactions of MAP with intestinal epithelium.
Insights
Mycobacterium avium spp. paratuberculosis (MAP) attachment to bovine intestinal cells varies by strain. This study developed an in vitro method to investigate MAP
Area of Science:
- Veterinary microbiology
- Bovine immunology
- Pathogenesis research
Background:
- Mycobacterium avium spp. paratuberculosis (MAP) causes intestinal inflammation in animals.
- Understanding MAP pathogenesis, particularly bacterial attachment to host cells, is crucial.
- Current knowledge of MAP-epithelial interactions remains limited.
Purpose of the Study:
- To establish an in vitro model for studying MAP attachment to bovine intestinal epithelial cells.
- To investigate strain-specific differences in MAP adherence.
- To explore the role of fibronectin in MAP attachment.
Main Methods:
- Utilized short-term bovine intestinal organ cultures.
- Employed radiolabeled MAP strains to quantify bacterial attachment.
- Analyzed tissue sections using acid-fast staining.
- Investigated the effect of fibronectin coating on MAP attachment.
Main Results:
- Demonstrated significant differences in attachment capabilities among various MAP strains.
- Observed no variation in MAP attachment across different intestinal regions.
- Found MAP organisms located adjacent to or within goblet cells of the epithelium.
- Noted varied effects of fibronectin coating on MAP strain attachment, without altering overall regional attachment.
Conclusions:
- The developed organ culture method effectively models MAP attachment to bovine intestinal epithelium.
- Strain variability is a key factor in MAP adherence.
- This model provides a platform for further elucidation of MAP-host interactions and molecular mechanisms of attachment.
