This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Protein Synthesis Inhibitors, Subject name: Pharmacology
[{'content': 'The most impoant mechanism by which gram negative bacilli acquire chloramphenicol resistance is: \nSelect and explain. \nA. Decreased permeability into the bacterial cell, B. Acquisition of a plasmid encoded for chloramphenicol acetyl transferase, C. Lowered affinity of the bacterial ribosome for chloramphenicol, D. Switching over from ribosomal to mitochondrial protein synthesis', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Resistance to chloramphenicol is usually by a plasmid encoded enzyme acetyltransferase which inactivates the drug. it can also be due to decreased permeability of the drug into the cell and also due to ribosomal mutation. Antimicrobial resistance through inactivating enzymes develops against: A: Aminoglycosides B: Beta lactams C: Chloramphenicol', 'role': 'assistant'}]