Bacterial reductions (represented as log ratio areas) of MRSA USA300 and USA400 are plotted as a function of vancomycin exposure. The fAUC/MICs needed to confer a reduction in the log ratio areas of 0.344, 1, 2, and 3 (black, blue, green, and purple, respectively) are listed above the corresponding vancomycin exposures. The data were described by a Hill-type function as described previously (25).