Correlation of Cell Membrane Lipid Profiles with Daptomycin Resistance in Methicillin-Resistant Staphylococcus aureus

We compared the cell membrane (CM) lipid composition among nine well-characterized daptomycin-susceptible (Dap(s))/Dap-resistant (Dap(r)) methicillin-resistant Staphylococcus aureus (MRSA) strain pairs. Compared to the 9 Daps parental strains, Dapr strains (with or without mprF-yycFG mutations) exhibited significantly reduced phosphatidylglycerol (PG) content (P < 0.01), significantly increased total synthesis of lysyl-PG (LPG) (P < 0.01), and reduced carotenoid content (P < 0.05 for 5/9 strains). There were no significant changes in LPG flipping, cardiolipin content, or fatty acid composition among strain pairs.