Fig. 4
From: Fierce poison to others: the phenomenon of bacterial dependence on antibiotics
Dependence to colistin. A Depiction of a normal Acinetobacter outer membrane, with the lipopolysaccharide (LPS) and phosphatidylglycerol (PG) components indicated. B Outer membrane of a CD strain. LPS production has been abrogated by genetic mutations. Other mutations are also likely involved in this trait. The membrane has increased PG content and presents a perturbed structure with alterations in the membrane potential. Also, oxidative stress levels are increased. C Membrane stabilization by colistin in a CD strain. Colistin binds the PG in the membrane in a localized fashion, increasing the membrane stability. Augmented peptidoglycan turnover by the activity of lytic transglycosylase may also have a role in membrane structure restoration. LPS: lipopolysaccharide, PG: phosphatidylglycerol, ROS: reactive oxygen species, CST: colistin, PPG: peptidoglycan layer, LT: lytic transglycosylase