title: Tea tree oil-induced transcriptional alterations in Staphylococcus aureus.
abstract: Tea tree oil (TTO) is a steam distillate of Melaleuca alternifolia that demonstrates broad-spectrum antibacterial activity. This study was designed to document how TTO challenge influences the Staphylococcus aureus transcriptome. Overall, bioinformatic analyses (S. aureus microarray meta-database) revealed that both ethanol and TTO induce related transcriptional alterations. TTO challenge led to the down-regulation of genes involved with energy-intensive transcription and translation, and altered the regulation of genes involved with heat shock (e.g. clpC, clpL, ctsR, dnaK, groES, groEL, grpE and hrcA) and cell wall metabolism (e.g. cwrA, isaA, sle1, vraSR and vraX). Inactivation of the heat shock gene dnaK or vraSR which encodes a two-component regulatory system that responds to peptidoglycan biosynthesis inhibition led to an increase in TTO susceptibility which demonstrates a protective role for these genes in the S. aureus TTO response. A gene (mmpL) encoding a putative resistance, nodulation and cell division efflux pump was also highly induced by TTO. The principal antimicrobial TTO terpene, terpinen-4-ol, altered ten genes in a transcriptional direction analogous to TTO. Collectively, this study provides additional insight into the response of a bacterial pathogen to the antimicrobial terpene mixture TTO.
authors.affiliation: Microbiology Group, Department of Biology, New Mexico State University, Las Cruces, NM 88003, USA.
authors.forename: Jesus A
authors.initials: JA
authors.lastname: Cuaron
authors.forename: Santosh
authors.initials: S
authors.lastname: Dulal
authors.forename: Yang
authors.initials: Y
authors.lastname: Song
authors.forename: Atul K
authors.initials: AK
authors.lastname: Singh
authors.forename: Cesar E
authors.initials: CE
authors.lastname: Montelongo
authors.forename: Wanqin
authors.initials: W
authors.lastname: Yu
authors.forename: Vijayaraj
authors.initials: V
authors.lastname: Nagarajan
authors.forename: Radheshyam K
authors.initials: RK
authors.lastname: Jayaswal
authors.forename: Brian J
authors.initials: BJ
authors.lastname: Wilkinson
authors.forename: John E
authors.initials: JE
authors.lastname: Gustafson
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D015536:Down-Regulation / Q000187:drug effects; D000431:Ethanol / Q000494:pharmacology; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000235:genetics; D020947:Tea Tree Oil / Q000494:pharmacology*; D013729:Terpenes / Q000494:pharmacology; D014158:Transcription, Genetic / Q000187:drug effects; D059467:Transcriptome / Q000187:drug effects*
chemical_list: D000900:Anti-Bacterial Agents; D013729:Terpenes; D000431:Ethanol; D020947:Tea Tree Oil