This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Bacteria, Subject name: Microbiology
[{'content': 'The mechanism of action of EPEC is: \nSelect and explain. \nA. Adherence to enterocytes, B. Stimulates adenylcyclase, C. Produce secretory diarrhea, D. None of the above', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e., Adherence to enterocytesENTEROPATHOGENIC E. COLIPathogenesis - Attaching-and-effacing histopathology.Three-stage model of EPEC pathogenesis: (i) Localized adherence(ii) Signal transduction(iii) Intimate adherence.Enteropathogenic E coli (EPEC) are an important cause of diarrhea in infants, especially in developing countries. EPEC adhere to the mucosal cells of the small bowel.Pathogenicity requires two important factors, the bundle forming pilus encoded by a plasmid EPEC adherence factor (EAF) and the chromosomal locus of enterocyte effacement (LEE) pathogenicity island that promote the tight adherence characteristic of EPEC (attachment and effacement). After attachment, there is loss of microvilli (effacement); formation of filamentous actin pedestals or cuplike structures.", 'role': 'assistant'}]