Which bacteria is Mupirocin particularly active against?

Mupirocin is particularly active against Staphylococcus aureus, a common bacterium often responsible for skin infections and other conditions. Its mechanism involves inhibiting bacterial protein synthesis by binding to the bacterial enzyme isoleucyl-tRNA synthetase, which is crucial for the incorporation of isoleucine into proteins. This action effectively halts the growth of bacteria, making Mupirocin a valuable treatment option for localized infections caused by Staphylococcus aureus, including methicillin-resistant strains (MRSA).

In contrast, while Mupirocin is not specifically targeted to treat infections caused by Escherichia coli, Streptococcus pyogenes, or Clostridium difficile, the other options represent different bacterial species with their own treatment protocols. For instance, Escherichia coli is typically treated with antibiotics like nitrofurantoin or trimethoprim-sulfamethoxazole, Streptococcus pyogenes infections often respond well to penicillin, and Clostridium difficile requires antibiotics such as vancomycin or fidaxomicin. This specificity in action highlights Mupirocin's role as an effective topical agent primarily against Staphylococcus aureus.