What is the mechanism of action of the C difficile toxin?
The toxin acts by modifying host cell GTPase proteins by glucosylation, leading to changes in cellular activities. Risk factors for C. difficile infection include antibiotic treatment, which can disrupt normal intestinal microbiota and lead to colonization of C. difficile bacteria.
What is C difficile toxin A B?
C. diff is a spore-forming, Gram-positive anaerobic bacillus that produces two exotoxins: toxin A and toxin B. It is a common cause of antibiotic-associated diarrhea (AAD) and accounts for 15 to 25% of all episodes of AAD.
How do the toxins of C difficile contribute to the signs of disease?
C. difficile causes disease by producing the toxins TcdA and TcdB that function to disrupt protein synthesis within the host cell. The toxins are responsible for producing symptoms such as watery diarrhea, fever, loss of appetite, nausea, and severe abdominal pain [1].
Which is worse C diff toxin A or B?
Only toxin-producing C diff strains cause disease and toxins A and B (encoded by the tcdA and tcdB genes) appear to play important roles. The toxins are pro-inflammatory enterotoxins, but toxin B is a more potent cytotoxin.
What do C diff toxins do to the body?
difficile bacteria enter the body through the mouth. They can begin reproducing in the small intestine. When they reach the large intestine (colon), they can release tissue-damaging toxins. These toxins destroy cells, produce patches of inflammatory cells and cellular debris, and cause watery diarrhea.
When does C diff produce toxins?
Once expression of the toxin genes is induced, the toxin proteins accumulate inside the cell and are slowly released over the course of several hours. In particular, upon reaching the intestine, C. difficile enters a vegetative state, begins to spread, and starts to secrete TcdA and TcdB [13].
What do C diff toxins do?
The pathogenicity of Clostridium difficile is mainly mediated by two exotoxins: toxin A (TcdA) and toxin B (TcdB). These toxins primarily disrupt the cytoskeletal structure and the tight junctions of target cells causing cell rounding and ultimately cell death.
What does toxin B do?
Both toxin A and toxin B are proinflammatory and cytotoxic, causing disruption of the actin cytoskeleton and impairment of tight junctions in human intestinal epithelial cells, with resulting fluid accumulation and extensive damage to the large intestine.
What is the difference between C diff toxin A and B?
Pathogenic strains of C difficile produce 2 distinct toxins. Toxin A is an enterotoxin, and toxin B is a cytotoxin; both are high–molecular weight proteins capable of binding to specific receptors on the intestinal mucosal cells.
What are the long term effects of C diff?
Among other infectious diseases (Shigella, Salmonella, and Campylobacter), long-term consequences such as irritable bowel syndrome (IBS), chronic dyspepsia/diarrhea, and other GI effects have been noted.