Background: Pseudomonas aeruginosa is intrinsically resistant to high levels of triclosan.
Methods: Using the agar incorporation method and defined mutant strains, the contribution of multidrug efflux pumps to high-level (>1,000 microg/mL) triclosan resistance in P aeruginosa was assessed.
Results: The results showed that the ability of P aeruginosa to survive in the presence of triclosan concentrations in excess of 1,000 microg/mL is solely attributable to the expression of efflux pumps.