135 Silencing Quorum Sensing molecule mechanisms to reduce harmful effects of two pathogenic bacteria on the skin

Bacteria use cell to communication system called quorum sensing (QS) share information about density and adjust gene expression accordingly. Processes controlled by QS include biofilm formation, virulence factor secretion swarming, responsible for bacteria harmful on the skin. Here we observed of two opportunistic skin bacteria: S. aureus (Sa) P. aeruginosa (Pa). Sa strongly disturbs barrier function secreting lipase forming a biofilm. For its part, Pa expresses an arsenal factors behavior like swarming which are under control molecules such as Acyl-homoserine lactone (3-oxo-C12 HSL) Pseudomonas Quinolone Signal (PQS). ATCC35556 was seeded alone, with reference inhibition (Glycyrrhizic ammonium salt at 0.2%) or plant extract (PE) 0.4%. After incubation, centrifugated filtered supernatants were incubated substrate measure activity fluorescence. 8h culture, formation visualized confocal microscopy. ATCC 15692 cultured (furanone PE quantified culture media HPLC-MS. 24h bacterial measured image analysis. We first evidenced that have no direct impact growth. Then, in decreased both (-24%) (-28%). Moreover, also reduced PE. Finally, significant decrease 3-oxo-C12-HSL PQS respectively -87% -97% furanone -72% -24% Additionally, (-67%). Taken altogether, these results demonstrated may be able effect silencing molecule mechanisms without affecting