Role of the MexAB-OprM Efflux Pump of Pseudomonas aeruginosa in Tolerance to Tea Tree ( Melaleuca alternifolia ) Oil and Its Monoterpene Components Terpinen-4-ol, 1,8-Cineole, and α-Terpineol

Abstract

Using a series of efflux mutants of Pseudomonas aeruginosa , the MexAB-OprM pump was identified as contributing to this organism's tolerance to the antimicrobial agent tea tree ( Melaleuca alternifolia ) oil and its monoterpene components terpinen-4-ol, 1,8-cineole, and α-terpineol. These data show that a multidrug efflux system of P. aeruginosa can extrude monoterpenes and related alcohols.