Bacterial Efflux Pumps

Bacterial efflux pumps are membrane-embedded protein complexes that actively transport a wide variety of substrates—including antibiotics, toxic compounds, metabolic byproducts, and signaling molecules—out of bacterial cells. This active export mechanism is a major contributor to antimicrobial resistance in bacteria by reducing the intracellular concentration of antibiotics below toxic levels. They are classified into several major families (ABC, MFS, RND, MATE, SMR, PACE), each utilizing different energy sources and having distinct substrate specificities. Efflux pumps play diverse roles beyond antibiotic resistance, including toxin removal, regulation of quorum sensing and biofilm formation, and modulation of membrane potential and redox state. Due to their significant contribution to multidrug resistance, they are considered important targets for novel antibacterial strategies. However, developing effective inhibitors remains challenging due to the structural diversity of these pumps.

Other names

Multidrug efflux pumpsDrug efflux pumpsEfflux transporters

Active transport of substrates across the bacterial cell membrane, reducing intracellular concentration.