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': 'Most common cause of infection due to catheter in urinary tract ? \nSelect and explain. \nA. E coli, B. Coagulase negative staphylococci, C. Staph aureus, D. Pseudomonas', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. is \'a\' i.e., E coli "E coli cause 80% of acute UTI in patients without catheterization". "E. coil is the most common cause of catheter associated UTI too".', 'role': 'assistant'}]