Selection for AMP resistance
To evaluate if populations of AMP-resistant bacteria could be selected, cultures were continuously exposed to Lynronne-1, Lynronne-2 and Lynronne-3 for a duration of 25 days, as previously described.40 Briefly, broth microdilution susceptibility testing was performed using a standard doubling-dilution series of Lynronne-1, Lynronne-2 and Lynronne-3 concentrations on day 1. Following incubation of the cultures for 24 h, and determination of the MIC, the well that contained the highest concentration of AMPs permitting growth was diluted 1: 1000 in MHB and used to provide the inoculum for the next MIC assay; this process was repeated daily for 25 days.