title: Inhibition of quorum sensing-controlled virulence factor production in Pseudomonas aeruginosa by South Florida plant extracts.
abstract: Quorum sensing (QS) is a key regulator of virulence and biofilm formation in Pseudomonas aeruginosa and other medically relevant bacteria. Aqueous extracts of six plants, Conocarpus erectus, Chamaesyce hypericifolia, Callistemon viminalis, Bucida buceras, Tetrazygia bicolor, and Quercus virginiana, were examined in this study for their effects on P. aeruginosa virulence factors and the QS system. C. erectus, B. buceras, and C. viminalis caused a significant inhibition of LasA protease, LasB elastase, pyoverdin production, and biofilm formation. Additionally, each plant presented a distinct effect profile on the las and rhl QS genes and their respective signaling molecules, suggesting that different mechanisms are responsible for efficacy. Extracts of all plants caused the inhibition of QS genes and QS-controlled factors, with marginal effects on bacterial growth, suggesting that the quorum-quenching mechanisms are unrelated to static or cidal effects.
authors.affiliation: Department of Biological Sciences, Florida International University, HLS673A, University Park, Miami, FL 33199, USA.
authors.forename: Allison
authors.initials: A
authors.lastname: Adonizio
authors.forename: Kok-Fai
authors.initials: KF
authors.lastname: Kong
authors.forename: Kalai
authors.initials: K
authors.lastname: Mathee
mesh_terms: D015107:4-Butyrolactone / Q000031:analogs & derivatives / Q000378:metabolism; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D018441:Biofilms / Q000187:drug effects / Q000254:growth & development; D005431:Florida; D015964:Gene Expression Regulation, Bacterial; D006801:Humans; D008517:Phytotherapy; D010936:Plant Extracts / Q000494:pharmacology*; D010946:Plants, Medicinal; D011550:Pseudomonas aeruginosa / Q000187:drug effects* / Q000254:growth & development / Q000472:pathogenicity*; D053038:Quorum Sensing / Q000187:drug effects*; D015398:Signal Transduction; D037521:Virulence Factors / Q000096:biosynthesis
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D010936:Plant Extracts; D037521:Virulence Factors; C088386:homoserine lactone; D015107:4-Butyrolactone