Carbon quantum dots derived from resveratrol enhances anti-virulence activity against Pseudomonas aeruginosa

Abstract

Resveratrol (Res), one phenolic compound derived from many kinds of fruits, has been shown to possess anti-virulence activity against the food spoilage bacterium Pseudomonas aeruginosa. However, the high usage and low activity limit its widespread application in food industry. In this study, Res was prepared into resveratrol carbon quantum dots (CQDRes) and the anti-virulence activity and anti-virulence mechanism of CQDRes were revealed for the first time. Exposure to CQDRes at 100 µg/mL significantly inhibited chemotaxis and the production of elastase, pyocyanin, rhamnolipid, and biofilms on the interface, and this inhibitory effect was higher than that of Res. Comprehensive transcriptome, proteomics, and parallel reaction monitoring analyses indicated that the pqs system of P. aeruginosa PAO1 was seriously disrupted after treatment with CQDRes while Res exposure had no such disrupted effect. The disrupted pqs system notably down-regulated the expressions of virulence-related genes and reduced the secretion of PQS-related signal molecules and pathogenicity of P. aeruginosa PAO1. The pqsC-knockout assay presented the reduced production of virulence factors and further confirmed the dysfunction of pqs system induced by CQDRes. These data indicated that CQDRes has the potential to function as an anti-virulence agent to defending against the foodborne pathogen P. aeruginosa.