Mupirocin is an antibiotic and bacterial metabolite that has been found in P. fluorescens. It is bacteriostatic against S. aureus (MIC = 0.05 µg/ml) and active against skin wound clinical isolates of methicillin-resistant S. aureus (MRSA; MICs = 1-4 µg/ml). Mupirocin inhibits MRSA and P. aeruginosa biofilm formation in vitro.4 It inhibits bacterial cell wall isoleucyl-tRNA synthetase, slowing bacterial growth. Topical administration of Mupirocin (2% v/v) reduces the number of wound colony forming units (CFUs) in a mouse model of MRSA skin infection. Lithium mupirocin as been used to study mupirocin resistance in staphylococcus aureus and in mycoplasma susceptibility studies.
