Antimicrobial Photodynamic therapy enhanced by the peptide aurein 1.2

• Published in: Scientific reports 2018-03, Vol.8 (1), p.4212-15, Article 4212
• Main Authors: de Freitas, Laura Marise, Lorenzón, Esteban Nicolás, Santos-Filho, Norival Alves, Zago, Lucas Henrique de Paula, Uliana, Marciana Pierina, de Oliveira, Kleber Thiago, Cilli, Eduardo Maffud, Fontana, Carla Raquel
• Format: Article
• Language: English
• Subjects: 631/326; 631/326/22; Antibiotic resistance; Antibiotics; Antimicrobial agents; Antimicrobial Cationic Peptides - metabolism; Antimicrobial Cationic Peptides - pharmacology; Antimicrobial peptides; Biological Transport; Cationic antimicrobial peptides; Cell Membrane - drug effects; Cell Membrane - metabolism; Cell Membrane - radiation effects; Combined treatment; Curcumin; Drug Resistance, Bacterial - drug effects; Drug Resistance, Bacterial - radiation effects; Drug Synergism; Enterococcus faecalis - cytology; Enterococcus faecalis - drug effects; Enterococcus faecalis - metabolism; Enterococcus faecalis - radiation effects; Humanities and Social Sciences; Humans; Methylene blue; Microorganisms; multidisciplinary; Peptides; Photochemotherapy; Photodynamic therapy; Photosensitizing Agents - pharmacology; Reactive Oxygen Species - metabolism; Science; Science (multidisciplinary); Therapeutic applications; Vancomycin
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-018-22687-x

In the past few years, the World Health Organization has been warning that the post-antibiotic era is an increasingly real threat. The rising and disseminated resistance to antibiotics made mandatory the search for new drugs and/or alternative therapies that are able to eliminate resistant microorganisms and impair the development of new forms of resistance. In this context, antimicrobial photodynamic therapy (aPDT) and helical cationic antimicrobial peptides (AMP) are highlighted for the treatment of localized infections. This study aimed to combine the AMP aurein 1.2 to aPDT using Enterococcus faecalis as a model strain. Our results demonstrate that the combination of aPDT with aurein 1.2 proved to be a feasible alternative capable of completely eliminating E . faecalis employing low concentrations of both PS and AMP, in comparison with the individual therapies. Aurein 1.2 is capable of enhancing the aPDT activity whenever mediated by methylene blue or chlorin-e6, but not by curcumin, revealing a PS-dependent mechanism. The combined treatment was also effective against different strains; noteworthy, it completely eliminated a vancomycin-resistant strain of Enterococcus faecium . Our results suggest that this combined protocol must be exploited for clinical applications in localized infections as an alternative to antibiotics.