Photodynamic and peptide-based strategy to inhibit Gram-positive bacterial biofilm formation

Author(s)

de Freitas, Laura Marise ^{[1, 2]} ; Lorenzon, Esteban Nicolas ^[3] ; Cilli, Eduardo Maffud ^[4] ; de Oliveira, Kleber Thiago ^[5] ; Fontana, Carla Raquel ^[1] ; Mang, Thomas S. ^[2]

Affiliation

^[1] Paulo State Univ, Sch Pharmaceut Sci, UNESP, Araraquara, SP - Brazil

^[2] Univ Buffalo, Dept Oral & Maxillofacial Surg, Sch Dent Med, Buffalo, NY 14260 - USA

^[3] Univ Fed Goias, Biol Sci Inst, Biochem & Mol Biol Dept, Campus 2 Samambaia, Goiania, Go - Brazil

^[4] Sao Paulo State Univ, Inst Chem, UNESP, Araraquara, SP - Brazil

^[5] Fed Univ Sao Carlos UFSCar, Dept Chem, Bioorgan Chem Lab, Sao Carlos, SP - Brazil

• Document type: Journal article
• Source: BIOFOULING; v. 35, n. 7, p. 742-757, AUG 9 2019.
• Web of Science Citations: 0

Abstract

The self-produced extracellular polymeric matrix of biofilms renders them difficult to eliminate once they are established. This makes the inhibition of biofilm formation key to successful treatment of biofilm infection. Antimicrobial photodynamic therapy (aPDT) and antimicrobial peptides offer a new approach as antibiofilm strategies. In this study sub-lethal doses of aPDT (with chlorin-e6 (Ce6-PDT) or methylene blue (MB-PDT)) and the peptides AU (aurein 1.2 monomer) or (AU)(2)K (aurein 1.2 C-terminal dimer) were combined to evaluate their ability to prevent biofilm development by Enterococcus faecalis. Biofilm formation was assessed by resazurin reduction, confocal microscopy, and infrared spectroscopy. All treatments successfully prevented biofilm development. The (AU)(2)K dimer had a stronger effect, both alone and combined with aPDT, while the monomer AU had significant activity when combined with Ce6-PDT. Additionally, it is shown that the peptides bind to the lipoteichoic acid of the E. faecalis cell wall, pointing to a possible key mechanism of biofilm inhibition.

• FAPESP's process: 18/23015-7 - Antimicrobial photodynamic therapy by continuous and switched mode irradiation against Enterococcus faecalis and Cutibacterium acnes
• Grantee: Carla Raquel Fontana Mendonça
• Support type: Regular Research Grants
• FAPESP's process: 14/24581-5 - Evaluation of the role of photodynamic therapy combined with antimicrobial peptides against bacterial resistance
• Grantee: Laura Marise de Freitas
• Support type: Scholarships in Brazil - Doctorate
• FAPESP's process: 16/18378-8 - Modification and enhancement of antimicrobial photodynamic therapy for the treatment of oral and head and neck infections
• Grantee: Laura Marise de Freitas
• Support type: Scholarships abroad - Research Internship - Doctorate