This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Anti Microbial, Subject name: Pharmacology
Mechanism of action of quinolones is? 
Select and explain. 
A. DNA gyrase inhibitors, B. Bind to 30 s unit, C. Bind to bacterial cell membrane, D. Bind to tetrahydofolate reductase
A: DNA gyrase inhibitors
Answer: A: DNA gyrase inhibitors 
Explanation: ANSWER: (A) DNA gyrase inhibitorsREF: Goodman G ill man s 11th ed p. 722The quinolone antibiotics target bacterial DNA gyrase and topoisomerase IV. For many gram positive bacteria, topoisomerase IV is the primary target. For many gram-negative bacteria, DNA gyrase is the primary quinolone target.