|Cell Wall: Gram Positive||Shape: Spore-forming Rod|
|Metabolism: Obligate Anaerobe|
- C. difficile spores are found widely in many environments but especially in hospitals where they often seed the GI system of hospitalized patients. However, extensive growth and release of exotoxin is normally held in check by the presence of the normal GI flora. However, treatment of broad-spectrum antibiotics such as clindamycin, ampicillin, as well as second and third generation cephalosporins often result in disruption of the normal GI flora allowing C. difficile over-growth, exotoxin release, and thus resulting in diarrheal disease.
- C. difficile produces two potent exotoxins
- Toxin A: An enterotoxin that disrupts enterocyte junctions, resulting in backleak of fluid into into the intestinal lumen
- Toxin B: A Cytotoxin that causes enterocyte death.
- The characteristic infectious diarrhea caused by C. difficile is termed "Pseudomembranous Colitis". Diarrhea is usually loose to watery and almost never contains blood. Endoscopic evaluation will reveal expanding colonic "Pseudomembranes" which are appear as whitish/yellowish plaques composed of necrotic cellular debris that overly colonic mucosal erosions. Pseudomembranes begin as small, millimeter-wide plaques of the colonic mucosa but expand and often coalesce to cover the entire large intestine.
- Infection can be confirmed using stool analysis for C. difficile enterotoxin.