Figure 4: Resistance to Peptoid TM5 could not be derived through laboratory evolution

<i>P. aeruginosa </i>PA01was serially passaged in increased concentrations of either (A) ciprofloxacin or (B) peptoids TM5. After 3 weeks of successive passaging in concentrations doubling weekly from 0.5XMIC-2XMIC, resistance of ciprofloxacin had readily emerged with the MIC increasing from 0.125 µg/mL to 8 µg/mL. In contrast, no increase in MIC was observed for peptoid TM5. To evaluate whether TM5 was effective against drug resistant strains, the newly evolved ciprofloxacin-resistant isolates were tested against peptoids TM5, which was found to be equally effective with a MIC of 4 µg/mL.