1. Crossing the envelope: how cephalosporins reach their targets
H. Nikaido 
Clinical Microbiology and Infection 
Volume 6, Pages (January 2000)
DOI: /j tb02036.x
Copyright © 2000 European Society of Clinical Infectious Diseases Terms and Conditions

2. Figure 1
Entry of β-lactam molecules into the periplasm of E. coli. Hydrophilic compounds cross the outer membrane mainly vie porin channels, especially the OmpF channels. Lipophilic compounds in contrast Cross the outer membrane mainly through the lipid bilayer domains. Compounds of both types may then be hydrolyzed by periplasmic β-lactamases, and the lipophilic ones may in addition be pumped out by the AcrAB-TolC multidrug efflux machinery. The steady-state concentration of drugs in the periplasm is determined by the balance among all these processes.
Clinical Microbiology and Infection 2000 6, 22-26DOI: ( /j tb02036.x)
Copyright © 2000 European Society of Clinical Infectious Diseases Terms and Conditions