Chemical Composition, Antibacterial and Anti-Quorum Sensing Activities of L. Essential Oil and Its Major Compound (Eugenol) against Foodborne Pathogenic Bacteria.

The essential oil and its main compound (eugenol) were tested for their antibacterial potency against eight Gram-negative and Gram-positive bacteria implicated in food intoxication. This essential oil and its main component were evaluated for their ability in inhibiting Quorum sensing (QS)-dependent mechanisms such as motility in PAO1, production of violacein by and biofilm formation on stainless steel and glass surfaces. Our results demonstrated that essential oil and eugenol were active against all tested strains with a maximum of inhibition against CECT 933 (26.66 ± 0.57 mm). The minimal inhibitory concentration (MIC) value of the tested essential oil and eugenol was about 0.048 mg/mL for all strains. The obtained results demonstrated that 4CMI eugenol inhibited foodborne strains biofilm formation on the glass strips by 73.79% and by 75.90% on polystyrene. Moreover, 0.048 mg/mL (MIC) of essential oil inhibited the violacein production by 69.30%. At 100 µg/mL, oil and eugenol affected the motility of PAO1 by 42.00% and 29.17%, respectively. Low concentrations of essential oil are active against the quorum sensing phenomena and biofilm potency. Thus, this essential oil could be further investigated for new molecules useful for the treatment of toxi-alimentary infections.