Elimination of intracellular MRSA in HaCaT keratinocytes. Keratinocytes were infected, treated with gentamicin to kill the extracellular S. aureus, and then treated with purified JDlys, CPP-JDlys, commercial lysostaphin, or vancomycin. Infected cells were treated with PBS as a control. *, the intracellular bacterial numbers after treatment with CPPTat-JDlys were significantly lower (P < 0.05) than those after the other treatments. The data shown are means ± SEMs from at least three independent experiments.