Mandarin fruit essential oil inhibit P. aeruginosa virulence factors

LUCIARDI C; CARTAGENA E; ARENA ME

Congreso; 3 ra Reunion Internacional de Ciencias Farmacéuticas; 2014

Antipathogenic compounds don´t kill bacteria or stop their growth. They rather control bacterial virulence factors like biofilm formation or elastase activity, and prevent the development of resistant strains. P. aeruginosa employs Quorum sensing (QS) to coordinate the communal behavior. The bacterial virulence factors have been shown to specifically involve the recognition and response to self-generated secreted small molecules called autoinducers. Gram negative bacteria produce N-acylhomoserine lactones (AHL) as quorum signal molecules. The interruption of QS by antipathogenic natural products from mandarin fruits was study. Mandarin oil is extracted from Citrus reticulata of the Rutaceae family. Essential oil and terpenes were obtained from regional industry while, bacterial strains came from ATCC collection, and from clinical isolates. The techniques used were: Crystal violet to measure biofilm formation, MTT assay to determine metabolic activity, Congo Red Test to measure elastolytic activity and Miller Test to quantify the AHL production. The higher biofilm inhibition was displayed by 4 mg/ml of terpenes against both strains P. aeruginosa: ATCC 27853 (88%), and clinical isolated (92%), in concordances with the higher viability inhibition (21% and 61%, respectively). The essential oil of mandarin, produce lower inhibitions against both strains (2-19%). Both mandarin natural products inhibit elastase activity (higher than 80%) even at 0.1 mg/ml, and this action is correlated with the lower AHL formation (inhibition between 30 to 50%). The use of local production of essential oil to inhibit P. aeruginosa virulence is a key strategy to employ this product to prevent food contamination by pathogenic bacteria and foodborne diseases.