Tea tree oil induced transcriptional alterations in Staphylococcus aureus

S. aureus and MRSA are susceptible to TTO and are therefore targeted in nascent TTO clinical trails. We now report the alterations in the transcriptome of a S. aureus exposed to a growth inhibitory concentration of TTO. These efforts have uncovered additional mechanisms by which this membrane active antimicrobial substance inhibits bacterial growth. Four hybridizations, including a biological replicate and a dye-swap experiment for each replicate was carried out. LOWESS normalization was performed on the raw data to correct for dye-bias. Statistical analysis was performed using a significance analysis of microarrays (SAM, MultiExperiment Viewer, ver. 4.0) unpaired contrast. A d-statistic was calculated for each gene based on repeated permutations, and a false discovery rate FDR of 0.01 was used to assign a critical cutoff for significance.