Figure 3. Time–kill curves of exponential phase P Figure 3. Time–kill curves of exponential phase P. aeruginosa NCTC 10662 treated with (a) tea tree oil: filled triangles, 0.125%; crosses, 0.25%; filled squares, 0.5%; (b) γ-terpinene: filled triangles, 0.1%; filled diamonds, 2%; or (c) terpinen-4-ol: filled triangles, 0.0625%; crosses, 0.125% with (open symbol, dotted line) or without (filled symbol, solid line) 250 μM CCCP pre-treatment. CCCP pre-treatment alone had no bactericidal activity (data not shown). The organisms were suspended in MHB-T. Each symbol indicates the mean±S.D. for at least three replicates. The lower detection threshold was 10<sup>3</sup> cfu/mL. From: Tolerance of Pseudomonas aeruginosa to Melaleuca alternifolia (tea tree) oil is associated with the outer membrane and energy-dependent cellular processes J Antimicrob Chemother. 2004;54(2):386-392. doi:10.1093/jac/dkh359 J Antimicrob Chemother | JAC vol.54 no.2 © The British Society for Antimicrobial Chemotherapy 2004; all rights reserved. 1