FIGURE 4.

Stability of AR-13 resistance. (A) Growth curve of LVS (WT) and the LVS AR-13 resistant mutant (MT) in the presence of various concentrations of AR-13 in mTSB. WT or MT were grown in twofold serial dilutions of AR-13 with a starting concentration of 10 μg/ml. Optical densities at 600nm (OD₆₀₀) were measured by a plate reader at 18 h after inoculation. (B) AR-13 resistance is stable. Approximately 1.5 × 10⁹ CFU of WT or MT after 10 overnight passes in AR-13-free mTSB (MT-10 passes) were incubated in 1 ml PBS containing 10 μg AR-13. Viable bacteria were evaluated at 3 h post-treatment by serial dilution and plating. Data were representative of 2–4 independent experiments each performed in triplicate; ^∗∗∗p < 0.001; NS, not significant.