Constitutive Activation of MexT by Amino Acid Substitutions Results in MexEF-OprN Overproduction in Clinical Isolates of Pseudomonas aeruginosa

Antimicrob Agents Chemother. 2018 Apr 26;62(5):e02445-17. doi: 10.1128/AAC.02445-17. Print 2018 May.

Abstract

When overproduced, the multidrug efflux system MexEF-OprN increases the resistance of Pseudomonas aeruginosa to fluoroquinolones, chloramphenicol, and trimethoprim. In this work, we demonstrate that gain-of-function mutations in the regulatory gene mexT result in oligomerization of the LysR regulator MexT, constitutive upregulation of the efflux pump, and increased resistance in clinical isolates.

Keywords: MexEF-OprN; MexT; Pseudomonas aeruginosa; antibiotic resistance.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Substitution / genetics
  • Amino Acid Substitution / physiology
  • Anti-Bacterial Agents / pharmacology
  • Drug Resistance, Bacterial / genetics
  • Gene Expression Regulation, Bacterial / genetics
  • Microbial Sensitivity Tests
  • Mutation / genetics
  • Pseudomonas aeruginosa / drug effects*
  • Pseudomonas aeruginosa / genetics

Substances

  • Anti-Bacterial Agents