Fig. 6.
(A) Influence of increasing calcium concentrations on efficacy of 30 μg/ml daptomycin. The difference in adherent MRSA cell numbers before and after daptomycin exposure is shown. Negative values denote killing. Values are means ± SD of results of six experiments. **, P < 0.01. (B and C) Influence of additional calcium ions (50 mg/liter) on daptomycin (DAP) efficiency (light gray bars) against planktonic (B) and adherent MRSA (C) in vivo. Inocula were 6 × 102 CFU/cage. Saline (open bars) and DAP without additional calcium (dark gray bars) served as controls. In panel B, positive values denote growth and negative values killing. Values are means ± SD. In panel C, efficacy against adherent MRSA was expressed as the prevention rate.