Pathogenic Mechanisms in C Diff Infection and Colitis

The purpose of this study is to examine pathogenic mechanisms of Clostridium difficile toxin-mediated intestinal injury and inflammation. Two primary mechanisms will be examined.

• To examine the hypothesis is that microRNA expression profiles are dysregulated by Clostridium difficile toxin exposure and that dysregulation of miRNA expression plays a role in the pathogenesis of C. difficile associated diseases.
• To examine the hypothesis is that the TLR9 receptor mediates key inflammatory events in response to Clostridium difficile toxin exposure.

Inclusion criteria

• Age greater than 18 yrs and less than 75 years
• Undergoing a clinically indicated colonoscopy

Exclusion criteria

• Known, active or recurrent colonic disease including: Clostridium difficile infection, inflammatory bowel disease, microscopic colitis, colon resection for any reason, ischemic colitis, recurrent diverticulitis, colon cancer. Note: Diverticulosis without recurrent diverticulitis, colonic adenomatous or hyperplastic polyps or colonic arteriovenous malformations will not constitute an exclusion
• Diarrhea (an average of more than 3 bowel movements per day at baseline)
• Constipation (an average of fewer than 2 bowel movements per week at baseline).
• Use of systemic steroid or systemic immunosuppressive medication
• Severe renal impairment
• Relative contraindication to colon biopsy including a bleeding diathesis or anti-coagulant use. Note: nonsteroidal antiinflammatory drug or asprin use will not constitute a contra-indication.