Figure 6.

The combined effect of CopA3 and Hp1090 against two E. coli strains. The combined antibacterial activity of the parental AMPs was tested against E. coli D31 (A,B) and E. coli JM83 (C,D). (A,C) The sublethal concentration of CopA3 was set at 15 µM and was combined with increasing concentrations of Hp1090. (B) The sublethal concentration of Hp1090 was set at 15 µM and was combined with increasing concentrations of CopA3. (D) The sublethal concentration of Hp1090 was set at 30 µM and was combined with increasing concentrations of CopA3. The AMP with the constant concentration is marked with an asterisk. The OD₆₀₀ was recorded using a microtiter plate reader. In each panel, the red line indicates the total inhibition of the combined treatment, the gray line shows the decreasing concentration of the serially-diluted AMP with the other sublethal concentration and the black line shows the bacterial growth curve in the absence of AMPs.