FIG 4.
Zeta potential measurements of surface charge of the phage and of CRKP. (A) Isoelectric point values of ФNJS1. Phage particles (108 PFU/ml) were resuspended in 2 μM KCl with different pH, and the zeta potential was measured. Means of results from three independent assays are shown, and error bars represent the standard deviations. (B) Zeta potential of colistins and colistinr CRKP. Mid-log-phase cells of WT, ΔmgrB, or WT containing the mcr-1 plasmid or mcr-1::Kmr were rinsed with ddH2O, and approximately 5 × 104 CFU/ml cells resuspended in ddH2O were used to measure zeta potential. *, P < 0.05 (2-way ANOVA); **, P < 0.005; ***, P < 0.0005; ns, no significance.