<prompt> Mechanism of action in pathogenesis of Pseudomembranous colitis by CI difficle ?Due to invasivenessDue to endotoxinDue to exotoxinDue to NM blockade  <response>: 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. 