Gene cloning and properties of the RND-type multidrug efflux pumps MexPQ-OpmE and MexMN-OprM from Pseudomonas aeruginosa

Microbiol Immunol. 2005;49(11):999-1002. doi: 10.1111/j.1348-0421.2005.tb03696.x.


We cloned two operons for putative RND-type multidrug efflux pumps from Pseudomonas aeruginosa by a PCR method. We designated the genes in one operon mexPQ(-opmE) and in another operon mexMN. Introduction of the mexPQ-opmE into drug hypersensitive cells resulted in elevated MICs of macrolides, fluoroquinolones and some other drugs. Introduction of the mexMN into the hypersensitive cells possessing oprM, but not into cells not possessing oprM, resulted in elevated MICs of chloramphenicol and thiamphenicol. Thus, we conclude that MexPQ-OpmE and MexMN-OprM are functional multidrug efflux pumps when expressed in P. aeruginosa.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Outer Membrane Proteins / genetics
  • Bacterial Outer Membrane Proteins / metabolism*
  • Bacterial Proteins / genetics*
  • Cloning, Molecular
  • Drug Resistance, Multiple / genetics*
  • Drug Resistance, Multiple / physiology
  • Genes, Bacterial*
  • Microbial Sensitivity Tests
  • Operon
  • Polymerase Chain Reaction
  • Pseudomonas aeruginosa / genetics*
  • Pseudomonas aeruginosa / isolation & purification


  • Bacterial Outer Membrane Proteins
  • Bacterial Proteins