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Daniel Otzen

Epigallocatechin Gallate Remodels overexpressed Functional Amyloids in Pseudomonas aeruginosa and Increases Biofilm Susceptibility to Antibiotic Treatment

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  • Marcel Stenvang, Sino-Danish Center
  • ,
  • Morten S Dueholm, Aalborg University, Denmark
  • Brian S Vad
  • ,
  • Thomas W Seviour
  • Guanghong Zeng
  • ,
  • Susana Geifman-Shochat, Nanyang Technological University
  • ,
  • Mads T Søndergaard, Aalborg University
  • ,
  • Gunna Christiansen
  • ,
  • Rikke Louise Meyer
  • Staffan Kjelleberg, Singapore Centre on Environmental Life Sciences Engineering (SCELSE), The University of New South Wales
  • ,
  • Daniel E Otzen
  • Per Halkjær Nielsen, Singapore Centre on Environmental Life Sciences Engineering (SCELSE), Aalborg University, Denmark

Epigallocatechin-3-gallate (EGCG) is the major polyphenol in green tea. It has anti-microbial properties and disrupts the ordered structure of amyloid fibrils involved in human disease. The anti-microbial 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 have 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 wildtype P. aeruginosa biofilms while EGCG had a more pronounced effect when Fap were overexpressed. Our results provide a direct molecular explanation for EGCG's ability to disrupt P. aeruginosa's QS and modify its biofilm, and strengthens the case for EGCG as a candidate in multidrug treatment of persistent biofilm infections.

Original languageEnglish
JournalJournal of Biological Chemistry
Pages (from-to)26540-26553
Publication statusPublished - 16 Dec 2016

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