Stress Response and Virulence Potential Modulating Effect of Peppermint Essential Oil in .

is one of the most common food-borne bacteria that causes gastrointestinal symptoms. In the present study we have investigated the molecular basis of the anti- effect of peppermint essential oil (PEO), one of the oldest EO used to treat gastrointestinal diseases. Transcriptomic, quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and proteomic, two-dimensional polyacryl amid gel electrophoresis (2D-PAGE) methods have revealed that, in the presence of a sublethal concentration of PEO, the expression of several virulence-associated genes was decreased ( 0.84x; 0.79x; 0.205x; 0.08x; 0.89x; 0.25x; 4.3x) while impaired motility was revealed with a functional analysis. Scanning electron micrographs of the exposed cells showed that, unlike in the presence of other stresses, the originally curved cells straightened upon PEO exposure. Gaining insight into the molecular background of this stress response, we have revealed that in the presence of PEO dominantly exerts a general stress response that elevates the expression of general stress genes like , , (10.41x, 3.63x, and 4.77x). The most important genes , , and involved in oxidative stress responses showed however moderate transcriptional elevations (1,58x, 1,55x, and 1,85x).