Role of the MexAB-OprM efflux pump of Pseudomonas aeruginosa in tolerance to tea tree (Melaleuca altenifolia) oil and its monoterpene components terpinen-4-ol, 1,8-cineole, and α-terpineol

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 alpha-terpineol. These data show that a multidrug efflux system of P. aeruginosa can extrude monoterpenes and related alcohols.