Which fluoroquinolone has activity against MRSA?

Which fluoroquinolone has activity against MRSA?

• A. Ciprofloxacin
• B. Levofloxacin
• C. Delafloxacin
• D. Moxifloxacin

Answer: (C)

Delafloxacin stands out because it has reliable activity against MRSA among the fluoroquinolones listed. MRSA resistance to fluoroquinolones usually involves mutations in the targets DNA gyrase and topoisomerase IV and other mechanisms like efflux. Delafloxacin is designed to inhibit both targets effectively in MRSA and retains potency even in acidic environments typical of infected tissue, which helps it work where other drugs may falter. In contrast, ciprofloxacin and levofloxacin mostly cover Gram-negative bacteria with limited or unreliable MRSA activity, and moxifloxacin, while active against many Gram-positives, does not provide robust MRSA coverage. So the best choice for MRSA activity among these options is delafloxacin.

Delafloxacin stands out because it has reliable activity against MRSA among the fluoroquinolones listed. MRSA resistance to fluoroquinolones usually involves mutations in the targets DNA gyrase and topoisomerase IV and other mechanisms like efflux. Delafloxacin is designed to inhibit both targets effectively in MRSA and retains potency even in acidic environments typical of infected tissue, which helps it work where other drugs may falter. In contrast, ciprofloxacin and levofloxacin mostly cover Gram-negative bacteria with limited or unreliable MRSA activity, and moxifloxacin, while active against many Gram-positives, does not provide robust MRSA coverage. So the best choice for MRSA activity among these options is delafloxacin.