Fig. 1: Winter Flounder AMP bactericidal activity is highly cooperative and can be influenced by synergy.

In vitro pharmacodynamics assays performed for selected WF peptides and combinations thereof, and bactericidal, clinically relevant antibiotics to which each strain remains susceptible: A. baumannii ATCC 17978 in MHB (a, b), A. baumanii AYE in MHB (c, d) or EMRSA-15 NCTC 13616 in RPMI with 5% FBS (e, f) were challenged with increasing concentrations of WF AMPs, WF AMP combinations or clinically relevant antibiotics. Curves shown are fits of averages of three independent repeated experiments (a, c, e) and show the change in bactericidal rate as a function of dose, reported as fractions or multiples of the MIC (×MIC). One-way ANOVA with Tukey post hoc test multiple comparisons for Kappa (b, d, f), highlight the differences in cooperativity between the WF AMPs, combinations thereof, and antibiotics. Mean and SE of three independent repeated experiments are shown. Only significant pairwise comparisons between AMPs or between clinically used antibiotics are shown (comparisons between AMPs and antibiotics are provided in the main text): *p < 0.05; **p < 0.01; ***p < 0.001; ****p < 0.0001. Selected time-kill curves, used to construct the PD curves in a, are provided in the supplementary material (Supplementary Fig. 1).