Bacterial Survival Under Antibiotic Selection Pressure: The Evasive End Run

The resistance developed by bacterial pathogens under antibiotic selection pressure compromises the durability of such antimicrobial treatments. However, an overlooked bacterial survival strategy is drug evasion through escape into host cells, within which antibiotic concentrations are sublethal.

Rodrigues et al. employed a murine gut colonization model to demonstrate the acquisition of mutations under cefepime selection pressure that did not influence cefepime susceptibility, but that enhanced bacterial evasion and survival within intestinal cells. Germ-free mice were colonized with a pan-susceptible Escherichia coli that had been isolated from the feces of a pediatric patient prior to stem-cell transplantation; the mice then received cefep…