MPO and Vancomycin-Resistant Staphylococcus Aureus Infection: It is evident from our study that VRSA infection in mice is associated with enhanced nitrate generation, MPO activity, MDA level, PC level, and GSSG level and decreased GSH level and as well as decreased enzymatic antioxidant (SOD, CAT, GPx, GR, and GST) activity in spleen, which are ameliorated by treatment of nanoconjugated vancomycin (Figures 3–7).