MPO and infection: It is evident from our study that, in vivo VSSA and VRSA infection in mice lymphocytes is associated with enhanced nitrate generation, nitrate release, MPO activity, MDA level, PC level, GSSG level, and decreased GSH level, and as well as decreased enzymatic antioxidant (SOD, CAT, GPx, GR, and GST) activity, which are ameliorated by treatment of nanoconjugated vancomycin (Figures 1–13).