Búsqueda de inhibidores de quorum sensing a partir de compuestos volátiles provenientes de aceites esenciales

Abstract

Quorum sensing (QS) is a communication mechanism between bacteria that allows controlling specific processes, such as biofilm formation, expression of virulence factors, production of secondary metabolites and mechanisms of resistance to stress; for this reason it has been used in the treatment of multi-resistant bacteria such as P. aeruginosa. The language used for intercellular communication is based on small signal-generating molecules called autoinducers (Acylhomoserinlactone), which can regulate the bacterial environment according to the density of the population. Given the strategies to inhibit quorum sensing, the use of Chromobacterium violaceum has been accepted as the biomarker in gram negative bacteria since it produces violacein, a quantifiable pigment that is produced when the bacterium performs QS. The objective of this work is to search for molecules of plant origin with the potential to inhibit quorum sensing. In this sense, the methodology included the development of a QS inhibition screen with 40 volatile compounds at a concentration of 100 μg / mL and subsequently the determination of the IC50 of the compounds that caused an inhibition greater than or equal to 50% of the maximum concentration. As complementary tests and that allow to glimpse the action of the compounds that passed the screening against the inhibition of quorum sensing in P. aeruginosa, it was sought to evaluate the susceptibility by diffusion test in agar per well. Of the 40 compounds evaluated, 17 were promising as QS inhibitors exhibiting IC50 with concentrations lower than 120 μg / mL, compounds such as nonanal, carvacrol, transanethole and safrole showed inhibition greater than 50% at concentrations of 8 μg / mL where it is concluded that there is a structural relationship in certain compounds that promote QS inhibition in Chromobacterium violaceum.