Antiquorum sensing and antimicrobial activity of aromatic species from South America

PELLEGRINI, MARÍA CELESTE; ALVAREZ, MARÍA VICTORIA; PONCE, ALEJANDRA; CUGNATA, NOELIA; DE PIANNO, FIORELA; ALONSO-SALCES, ROSA MARÍA; FUSELLI, SANDRA

Bruselas

Simposio; AFERP & STOLON International Symposium; 2013

Université Catholique de Louvain & Université Libre de Bruxelles

Quorum sensing (QS) is a bacterial communication mechanism that depends on microbial population density (1). The interruption of QS is one example of an antipathogenic effect and can be used in the treatment of bacterial infections (2). We investigated the anti-QS and antimicrobial properties of six essential oils from aromatic species from Argentina: Salvia oficinallis, Minthostachys mollis, Satureja odora, Schinus molle, Lepechinia floribunda and Artemisia annua. The anti-QS activity was determined using UV-visible spectrophotometry to measure the violacein production by Chromobacterium violaceum. The effective concentration of bioactivity at which the QS activity was reduced at 50% (MQSIC), was calculated. The antimicrobial activity was determined using C. violaceum, Escherichia coli, Listeria innocua and Staphylococus aureus as indicators. The minimum inhibitory concentration (MIC) and the minimal bactericide concentration (MBC) were determined by broth microdilutions method for each strain. Probit analysis was performed to analyze the violacein production data. All the oils have potential anti-QS activity at sub-lethal concentrations on C. violaceum. The M. mollis oil showed a greater anti-QS activity: diluted at 0.02% (v/v), violacein production decreased 90%. S. molle essential oil showed the lowest MQSIC (0.005%, v/v). S. molle and M. mollis oils exhibited the highest bacteriostatic (0.32% (v/v) for both oils) and bactericidal activity (0.64% (v/v) and 1.13% (v/v), respectively.