Which antibiotic has good activity against MRSA?

• A. Lincomycin
• B. Trimethoprim-Sulfamethoxazole Combo
• C. Vancomycin
• D. Clindamycin

Answer: (B)

The main idea here is how MRSA responds to common antibiotics and why a particular drug is a good outpatient option. Trimethoprim-sulfamethoxazole works by blocking two sequential steps in bacterial folate synthesis, making the combination bactericidal. This dual blockade gives robust activity against many MRSA strains, and the medication has excellent oral bioavailability with good tissue penetration, which makes it a reliable choice for outpatient treatment of MRSA skin and soft tissue infections and some ocular infections.

While vancomycin is highly active against MRSA, it is typically reserved for more serious infections that require intravenous therapy, and clindamycin can be effective but is limited by inducible resistance and a higher risk of C. difficile. Lincomycin is less commonly used. So, for good activity against MRSA in a readily usable outpatient context, trimethoprim-sulfamethoxazole stands out as a strong option.