Porins, efflux pumps and multidrug resistance in Acinetobacter baumannii

J Antimicrob Chemother. 2007 Jun;59(6):1210-5. doi: 10.1093/jac/dkl509. Epub 2007 Feb 26.


Acinetobacter baumannii is an opportunistic pathogen, causing infections mainly in patients in intensive care units where the extensive use of antimicrobial agents can select for the emergence of multiresistant strains. In fact, since strains resistant to all antimicrobial agents have been reported, A. baumannii is considered the paradigm of multiresistant bacteria. Both acquired and intrinsic resistance can contribute to multiresistance. The ability to acquire multidrug resistance can be due to either the acquisition of genetic elements carrying multiple resistant determinants or mutations affecting the expression of porins and/or efflux pump(s), which can affect unrelated antimicrobial agents. Meanwhile, intrinsic resistance can be generated by the interplay of decreased permeability and constitutive expression of active efflux systems and it too can affect unrelated antimicrobial agents. This review is focused on the current knowledge of porins and efflux pump(s) in this microorganism.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • ATP Binding Cassette Transporter, Subfamily B / metabolism*
  • Acinetobacter baumannii / drug effects*
  • Acinetobacter baumannii / metabolism*
  • Bacterial Outer Membrane Proteins / metabolism
  • Drug Resistance, Multiple, Bacterial / physiology*
  • Humans
  • Porins / metabolism*


  • ATP Binding Cassette Transporter, Subfamily B
  • Bacterial Outer Membrane Proteins
  • Porins