Which antibiotic is used as a first-line treatment for community-acquired pneumonia caused by Staphylococcus aureus?

Vancomycin is the first-line treatment recommended for community-acquired pneumonia caused by Staphylococcus aureus, particularly when the strain is methicillin-resistant Staphylococcus aureus (MRSA). This antibiotic works by inhibiting cell wall synthesis in bacteria, which is critical for their growth and survival.

Staphylococcus aureus, especially the MRSA variant, is a significant cause of pneumonia, and vancomycin is particularly effective against it due to its strong affinity for the bacterial cell wall and its ability to penetrate tissues effectively in the setting of pneumonia.

In cases of community-acquired pneumonia, the choice of antibiotic must take into consideration the most likely pathogens and their resistance patterns. Vancomycin is favored in this context to ensure effective coverage against resistant strains that may not respond to other types of beta-lactam antibiotics.

Other antibiotics listed may be considered for different pathogens or types of pneumonia but do not specifically target Staphylococcus aureus with the same efficacy as vancomycin in this particular clinical scenario.