title: Bacterial resistance to antibiotics: active efflux and reduced uptake.
abstract: Antibiotic resistance of bacterial pathogens is a fast emerging global crisis and an understanding of the underlying resistance mechanisms is paramount for design and development of new therapeutic strategies. Permeability barriers for and active efflux of drug molecules are two resistance mechanisms that have been implicated in various infectious outbreaks of antibiotic-resistant pathogens, suggesting that these mechanisms may be good targets for new drugs. The synergism of reduced uptake and efflux is most evident in the multiplicative action of the outer membrane permeability barrier and active efflux, which results in high-level intrinsic and/or acquired resistance in many clinically important Gram-negative bacteria. This review summarizes the current knowledge of these two important resistance mechanisms and potential strategies to overcome them. Recent advances in understanding the physical structures, function and regulation of efflux systems will facilitate exploitation of pumps as new drug targets.
authors.affiliation: Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, CO, USA.
authors.forename: Ayush
authors.initials: A
authors.lastname: Kumar
authors.forename: Herbert P
authors.initials: HP
authors.lastname: Schweizer
mesh_terms: D000900:Anti-Bacterial Agents / Q000378:metabolism / Q000494:pharmacology*; D001424:Bacterial Infections / Q000188:drug therapy* / Q000382:microbiology; D001426:Bacterial Proteins / Q000502:physiology; D001692:Biological Transport; D024901:Drug Resistance, Multiple, Bacterial; D006801:Humans; D008954:Models, Biological; D027425:ATP-Binding Cassette, Sub-Family C Proteins / Q000502:physiology
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D027425:ATP-Binding Cassette, Sub-Family C Proteins; C075040:NorA protein, Staphylococcus