FIG 1.

Intracellular Staphylococcus epidermidis amounts in MC-3T3-E1 osteoblasts after 24 h of rifamycin exposure. (A) SE1457, (B) IDRL-8864, (C) IDRL-8933, (D) IDRL-9950, (E) IDRL-6515, and (F) RP62A and RP62A-ΔrpoB intracellular concentration (CFU/ml) after 3.5 h infection of MC-3T3-E1 cells and subsequent 24 h treatment with no treatment (untreated) or 16 μg/ml rifampin, rifapentine, or rifabutin shown. Rifampin-susceptible isolates are shown in black, with rifampin-resistant isolates shown in red. Data are depicted as the mean of experimental triplicates plus standard error of the mean for n = 3 experiments. *, P ≤ 0.05; **, P ≤ 0.01; ***, P ≤ 0.001 (one-way analysis of variance [ANOVA]).