title: Epigallocatechin Gallate Remodels Overexpressed Functional Amyloids in Pseudomonas aeruginosa and Increases Biofilm Susceptibility to Antibiotic Treatment.
abstract: Epigallocatechin-3-gallate (EGCG) is the major polyphenol in green tea. It has antimicrobial properties and disrupts the ordered structure of amyloid fibrils involved in human disease. The antimicrobial effect of EGCG against the opportunistic pathogen Pseudomonas aeruginosa has been shown to involve disruption of quorum sensing (QS). Functional amyloid fibrils in P. aeruginosa (Fap) are able to bind and retain quorum-sensing molecules, suggesting that EGCG interferes with QS through structural remodeling of amyloid fibrils. Here we show that EGCG inhibits the ability of Fap to form fibrils; instead, EGCG stabilizes protein oligomers. Existing fibrils are remodeled by EGCG into non-amyloid aggregates. This fibril remodeling increases the binding of pyocyanin, demonstrating a mechanism by which EGCG can affect the QS function of functional amyloid. EGCG reduced the amyloid-specific fluorescent thioflavin T signal in P. aeruginosa biofilms at concentrations known to exert an antimicrobial effect. Nanoindentation studies showed that EGCG reduced the stiffness of biofilm containing Fap fibrils but not in biofilm with little Fap. In a combination treatment with EGCG and tobramycin, EGCG had a moderate effect on the minimum bactericidal eradication concentration against wild-type P. aeruginosa biofilms, whereas EGCG had a more pronounced effect when Fap was overexpressed. Our results provide a direct molecular explanation for the ability of EGCG to disrupt P. aeruginosa QS and modify its biofilm and strengthens the case for EGCG as a candidate in multidrug treatment of persistent biofilm infections.
authors: From the Interdisciplinary Nanoscience Center (iNANO).|Department of Molecular Biology and Genetics, Center for Insoluble Protein Structures (inSPIN).|the Sino-Danish Centre for Education and Research (SDC), 8000 Aarhus C, Denmark.
authors: Marcel
authors: M
authors: Stenvang
authors: the Center for Microbial Communities, Department of Chemistry and Bioscience, Aalborg University, 9000 Aalborg, Denmark.
authors: Morten S
authors: MS
authors: Dueholm
authors: From the Interdisciplinary Nanoscience Center (iNANO).|Department of Molecular Biology and Genetics, Center for Insoluble Protein Structures (inSPIN).
authors: Brian S
authors: BS
authors: Vad
authors: the Singapore Centre on Environmental Life Sciences Engineering (SCELSE), Singapore 637551, Singapore.
authors: Thomas
authors: T
authors: Seviour
authors: From the Interdisciplinary Nanoscience Center (iNANO).
authors: Guanghong
authors: G
authors: Zeng
authors: the School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore, and.
authors: Susana
authors: S
authors: Geifman-Shochat
authors: the Center for Microbial Communities, Department of Chemistry and Bioscience, Aalborg University, 9000 Aalborg, Denmark.
authors: Mads T
authors: MT
authors: Søndergaard
authors: the Department of Biomedicine, and.
authors: Gunna
authors: G
authors: Christiansen
authors: From the Interdisciplinary Nanoscience Center (iNANO).|the Department of Bioscience, Aarhus University, 8000 Aarhus C, Denmark.
authors: Rikke Louise
authors: RL
authors: Meyer
authors: the Singapore Centre on Environmental Life Sciences Engineering (SCELSE), Singapore 637551, Singapore.|the Centre for Marine Bio-innovation and School of Biotechnology and Biomolecular Science, University of New South Wales, Mosman, New South Wales 2088, Australia.
authors: Staffan
authors: S
authors: Kjelleberg
authors: the Center for Microbial Communities, Department of Chemistry and Bioscience, Aalborg University, 9000 Aalborg, Denmark.|the Singapore Centre on Environmental Life Sciences Engineering (SCELSE), Singapore 637551, Singapore.
authors: Per Halkjær
authors: PH
authors: Nielsen
authors: From the Interdisciplinary Nanoscience Center (iNANO), dao@inano.au.dk.|Department of Molecular Biology and Genetics, Center for Insoluble Protein Structures (inSPIN).
authors: Daniel E
authors: DE
authors: Otzen
mesh_terms: D000682:Amyloid / Q000096:biosynthesis*; D001426:Bacterial Proteins / Q000096:biosynthesis*; D052160:Benzothiazoles; D018441:Biofilms / Q000187:drug effects* / Q000254:growth & development; D002392:Catechin / Q000031:analogs & derivatives* / Q000494:pharmacology; D024881:Drug Resistance, Bacterial / Q000187:drug effects*; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects*; D006801:Humans; D011552:Pseudomonas Infections / Q000188:drug therapy / Q000378:metabolism; D011550:Pseudomonas aeruginosa / Q000502:physiology*; D013844:Thiazoles / Q000494:pharmacology; D014031:Tobramycin / Q000494:pharmacology*
chemical_list: D000682:Amyloid; D001426:Bacterial Proteins; D052160:Benzothiazoles; D013844:Thiazoles; C009462:thioflavin T; D002392:Catechin; C045651:epigallocatechin gallate; D014031:Tobramycin
keywords: Pseudomonas aeruginosa (P. aeruginosa); amyloid; bacterial fibrils; biofilm; epigallocatechin gallate (EGCG); fibril; fibrillation inhibition; nanoindentation; natural product; pyocyanin binding