Eugenol: a potent quorum sensing inhibitor to restrict Pseudomonas aeruginosa pathogenicity

Background and Aim : Pseudomonas aeruginosa is an opportunistic human pathogen. This is one of the most important causes for nosocomial infections in immunocompromised patients. It produces a wide range of virulence factors and is highly resistant to lots of usual antibiotics. Production of virulence factors in this bacterium is under control of quorum sensing (QS) system. QS is a highly attractive target for the development of novel therapeutics. Eugenol is a major component of clove oil. Previous studies have shown its antibacterial activities. This study aimed to determine the in vitro anti-QS activity of eugenol on QS-regulated biofilm formation and virulence factors production in P. aeruginosa.Methods : The minimum inhibitory concentration (MIC) of eugenol was determined against P. aeruginosa ATCC ۲۷۸۵۳, P. aeruginosa PAO۱ and three clinical isolates. The effect of eugenol on bacterial proliferation was also determined by monitoring the growth curve. The biofilm formation, exopolysaccharide (EPS), pyocyanin and rhamnolipid production, swimming, swarming and twitching motility were evaluated after eugenol treatment.Results : The MICs against P. aeruginosa ATCC ۲۷۸۵۳ and P. aeruginosa PAO۱ were ۰.۳% v/v and ۰.۶% v/v, respectively. Different concentrations of eugenol (≤۰.۱۵%) demonstrated statistically significant reduction of virulence factors including pyocyanin and rhamnolipid production. Biofilm formation, EPS production, swarming, swimming and twitching motility were also reduced after eugenol treatment.Conclusion : These results indicate that the use of eugenol as a potent QS inhibitor and anti-biofilm agent would be an effective therapeutic strategy for combating P. aeruginosa infections.

کلیدواژه ها:

Eugenol ، Pseudomonas aeruginosa ، Quorum sensing