Oritavancin-induced membrane depolarization and cell killing of VISA, VRSA, and VREF isolates are tightly correlated. (A to C) Correlations were determined for VISA ATCC 700699 (A), VRSA VRS5 (B), and VanB VREF ATCC 51299 (C). Oritavancin was used at 0.5 μg/ml (▵), 1 μg/ml (▴), 2 μg/ml (□), 4 μg/ml (▪), 8 μg/ml (○), and 16 μg/ml (•).