Fig. 3. Serial passage resistance induction of AA139 against susceptible and MDR Gram-negative bacteria.

MIC values for AA139 before and after each of 20 passages (1 passage per 24 h, n = 1) treated with 0.5× MIC μg mL⁻¹ (of previous passage). Bacteria that grew at the highest concentration of AA139 on the final passage were passaged a further 3 times on drug-free agar plates before determining the final MIC by BMD (“Post”, gray shading). Tabulated MIC values for AA139 and arenicin-3 are presented in Supplementary Table 7. Strains used in this study are detailed by (^#) in Supplementary Data 3.