Cellular and Molecular Life Sciences CMLS

, Volume 56, Issue 9, pp 771–778

Bacterial antibiotic efflux systems of medical importance

  • T. Köhler
  • J.-C. Pechère
  • P. Plésiat

DOI: 10.1007/s000180050024

Cite this article as:
Köhler, T., Pechère, J. & Plésiat, P. CMLS, Cell. Mol. Life Sci. (1999) 56: 771. doi:10.1007/s000180050024

Abstract.

Multidrug efflux systems endow on bacterial cells the ability to limit the access of antimicrobial agents to their targets. By actively pumping out antibiotic molecules, these systems prevent the intracellular accumulation necessary for antibiotics to exert their lethal activity. Drug efflux appears to be one of the most widespread antibiotic resistance mechanisms among microorganisms, since it has been demonstrated to occur in many Gram-positive and Gram-negative bacteria including medically important species like staphylococci, streptococci, enterobacteria and opportunistic pathogens like Pseudomonas aeruginosa. Efflux pumps can be specific for only one substrate or accommodate a more or less wide range of noxious products. Export of structurally unrelated compounds confers a multidrug-resistance phenotype on bacterial cells. Therapeutically critical levels of resistance can be achieved by overexpression of efflux systems, especially in those species such as P. aeruginosa which possess a low outer membrane permeability. It is suspected that the dual physiological function of active efflux systems is both the secretion of intracellular metabolites and the protection against a variety of harmful substances that the microorganism may encounter in its natural environment.

Key words. Multidrug resistance; microorganisms; efflux; resistance mechanism.

Copyright information

© Birkhäuser Verlag Basel, 1999

Authors and Affiliations

  • T. Köhler
    • 1
  • J.-C. Pechère
    • 1
  • P. Plésiat
    • 2
  1. 1.Department of Genetics and Microbiology, Centre Médical Universitaire, 9, av. de Champel, CH-1211 Geneva 4 (Switzerland), Fax +41 22 7025702, e-mail: Thilo.Kohler@medecine.unige.chCH
  2. 2.University Hospital Center Besançon, F-25030 Besançon cedex (France)FR