Peptidomimetic Antibiotics Target Outer-Membrane Biogenesis in Pseudomonas aeruginosa 1. How was it determined that the synthesized peptidomimtic antibiotics have a different killing mechanism than natural peptide protegrin I, which is present in host-defenses? 2. What was determined to be the mechanism by which the peptidomimetic antibiotics killed the bacteria? 3. What is the significance of showing the activity of these antibiotics in vivo?