This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Microbiology
[{'content': 'Mechanism of action in pathogenesis of Pseudomembranous colitis by CI difficle ? \nSelect and explain. \nA. Due to invasiveness, B. Due to endotoxin, C. Due to exotoxin, D. Due to NM blockade', 'role': 'user'}, {'content': "Answer: C \nExplanation: Ans. is 'c' i.e., Due to exotoxin Pathogenesis of pseudomembranous colitis is due to production of two large toxins by C. difficile : i) Toxin A (an enterotoxin) Is a potent neutrophil chemoattractant Causes disruption of cell cytoskeleton by glycosylation of GTP - binding proteins that regulate the actin cell cytoskeleton. ii) Toxin B (a cytotoxin) Causes disruption of cell cytoskeleton by similar mechanism.", 'role': 'assistant'}]