title: Quercetin is an effective inhibitor of quorum sensing, biofilm formation and virulence factors in Pseudomonas aeruginosa.
abstract: OBJECTIVE
  The study aimed to perform a systematic investigation of the effects of quercetin on biofilm formation and virulence factors in Pseudomonas aeruginosa.
  
  
  RESULTS
  The Ps. aeruginosa strain PAO1 was selected as the test strain. The results indicated that quercetin did not impact the growth of PAO1 as determined by MIC and growth curve analysis. However, this compound significantly inhibited (P < 0·05) biofilm formation and production of virulence factors including pyocyanin, protease and elastase at a lower concentration than those for most previously reported plant extracts and substances. Considering the central role of quorum sensing (QS) in the regulation of biofilm and virulence factor, we further detected the transcriptional changes associated with QS and found that the expression levels of lasI, lasR, rhlI and rhlR were significantly reduced (P < 0·05) by 34, 68, 57 and 50%, respectively, in response to 16 μg ml(-1) quercetin.
  
  
  CONCLUSIONS
  This study indicated that quercetin is an effective inhibitor of biofilm formation and virulence factors in Ps. aeruginosa.
  
  
  CONCLUSIONS
  This is the first study to demonstrate that quercetin is an effective inhibitor of QS, biofilm formation and virulence factors in Ps. aeruginosa. Furthermore, quercetin might have potential in fighting biofilm-related infections.
authors.affiliation: Department of Pharmacy, Southwest Hospital of the Third Military Medical University, Chongqing, China.
authors.forename: J
authors.initials: J
authors.lastname: Ouyang
authors.affiliation: Department of Pharmacy, Southwest Hospital of the Third Military Medical University, Chongqing, China.
authors.forename: F
authors.initials: F
authors.lastname: Sun
authors.affiliation: Department of Pharmacy, Southwest Hospital of the Third Military Medical University, Chongqing, China.
authors.forename: W
authors.initials: W
authors.lastname: Feng
authors.affiliation: Department of Pharmacy, Southwest Hospital of the Third Military Medical University, Chongqing, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Sun
authors.affiliation: Department of Pharmacy, Southwest Hospital of the Third Military Medical University, Chongqing, China.
authors.forename: X
authors.initials: X
authors.lastname: Qiu
authors.affiliation: Department of Pharmacy, Southwest Hospital of the Third Military Medical University, Chongqing, China.
authors.forename: L
authors.initials: L
authors.lastname: Xiong
authors.affiliation: Department of Pharmacy, Southwest Hospital of the Third Military Medical University, Chongqing, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Department of Pharmacy, Southwest Hospital of the Third Military Medical University, Chongqing, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Chen
mesh_terms: D018441:Biofilms / Q000187:drug effects / Q000254:growth & development; D011550:Pseudomonas aeruginosa / Q000187:drug effects* / Q000502:physiology; D011794:Quercetin / Q000494:pharmacology*; D053038:Quorum Sensing / Q000187:drug effects*; D037521:Virulence Factors / Q000032:analysis / Q000096:biosynthesis*
chemical_list: D037521:Virulence Factors; D011794:Quercetin
keywords: Pseudomonas aeruginosa; biofilm; quercetin; quorum sensing; virulence factors