Can resveratrol, a quorum sensing inhibitor, function as an aminoglycoside antibiotic-accelerant against Pseudomonas aeruginosa?

Pseudomonas aeruginosa infection is a serious disease in cystic fibrosis (CF) patients and is difficult to cure due to biofilm persistence and emerging multidrug resistance. Considering the essential role of quorum sensing (QS) in P. aeruginosa infections, the enhanced effects between quorum sensing inhibitor (QSI) resveratrol and several antibiotics against P. aeruginosa PAO1 were investigated. Crystal violet staining assay revealed that the biofilms of P. aeruginosa PAO1 grown in the presence of resveratrol were more susceptible to aminoglycoside antibiotics. Scanning electron and fluorescence microscopy showed architectural disruption of the biofilms when treated with resveratrol and aminoglycoside antibiotics. Furthermore, qRT-PCR analysis demonstrated that the expressions of lasI and rhlI, two genes that encode enzymes to synthesize signal molecules in QS systems, were inhibited in the P. aeruginosa PAO1 biofilms by resveratrol. These results indicate that QSI resveratrol can significantly enhance the effects of aminoglycoside antibiotics (i.e., tobramycin, gentamycin, amikacin, and netilmicin) on P. aeruginosa PAO1 biofilms. Our findings suggest that resveratrol is a potential accelerant in the treatment of P. aeruginosa biofilms and can restore or enhance the efficacy of aminoglycoside antibiotics.