🦠microbiology review

Clostridium difficile toxin A

Written by the Fiveable Content Team • Last updated September 2025
Written by the Fiveable Content Team • Last updated September 2025

Definition

Clostridium difficile toxin A is an exotoxin produced by the bacterium Clostridium difficile. It primarily causes inflammation and increased permeability of the intestinal mucosa, leading to diarrhea and colitis.

5 Must Know Facts For Your Next Test

  1. Toxin A is one of the main virulence factors of Clostridium difficile, contributing to its pathogenicity.
  2. It acts by disrupting the cytoskeleton of intestinal epithelial cells, causing cell death and inflammation.
  3. Toxin A is known to increase fluid secretion into the intestine, resulting in watery diarrhea.
  4. The presence of both toxin A and B is often used as a diagnostic indicator for Clostridium difficile infection (CDI).
  5. Antibiotic use, particularly broad-spectrum antibiotics, can disrupt normal gut flora making individuals more susceptible to infection by C. difficile.

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