Proteome Differences between Daptomycin-Resistant and WT MRSA Biofilms after Elasnin Treatment

A recent study reported that daptomycin-resistant MRSA (DAPR) strain biofilm is more resistant to daptomycin and vancomycin, as compared to the WT strain biofilm. This pose a great danger since DAPR MRSA is prevalent in clinics and they often form biofilms in medical devices. In this study, we investigate the anti-biofilm activity of elasnin against DAPR MRSA biofilms, and we observed that elasnin is not only effective to eradicate the biofilm of the DAPR strain, but it shows a superior activity compared to the susceptible WT strain. Using proteomics, we compared the proteome profile of the DAPR and the WT strain biofilm cells under elasnin treatment to reveal why elasin is superior against the DAPR strain. Besides, we also employed adaptive laboratory evolution (ALE) experiment by repetitively treating MRSA culture with high dose of elasnin, and generated evolved MRSA strain with increased elasnin tolerance. Using quantitative proteomics, we compared the proteome differences in the elasnin-susceptible WT MRSA and elasnin-tolerant evolved strain.