Comparative lipidomics profiles of planktonic and biofilms of methicillin-resistant and -susceptible Staphylococcus aureus

Staphylococcus aureus is a significant human pathogen causing acute life-threatening, and chronic infections often linked to biofilms. This study conducted a comparative lipidomic analysis of a methicillin-resistant (MRSA) and a methicillin-susceptible (MSSA) S. aureus strain in both planktonic and biofilm cultures using liquid chromatography-mass spectrometry (LC-MS) and nuclear magnetic resonance (NMR) spectroscopy. The developed protocol successfully differentiates between the strains in various living states (planktonic and biofilm) and growth media (Tryptic Soy Broth and Brain Heart Infusion) using S. aureus USA300 LAC (MRSA) and S. aureus Newman (MSSA). LC-MS and NMR lipidomics profiles revealed global differences and particular ones among the following classes of bacterial lipids: phosphatidylglycerols, diacylglycerols, monoglycosyldiacylglycerols, diglycosyldiacylglycerols, and cardiolipins. Lipid content was higher in the biofilm states for most of these classes. Growth media differences were significant, while differences between MRSA and MSSA were less pronounced but still detectable. Additionally, we provide data on hundreds of unknown compounds that differ based on living state, strain background, or growth media. This study offer insights into the dynamic nature of S. aureus lipid composition and the used methods are adaptable to other organisms.