Antimicrobial Photodynamic therapy enhanced by the peptide aurein 1.2

May 22, 2018

Title

Antimicrobial Photodynamic therapy enhanced by the peptide aurein 1.2

Author

Laura Marise de Freitas, Esteban Nicolás Lorenzón, Norival Alves Santos-Filho, Lucas Henrique de Paula Zago, Marciana Pierina Uliana, Kleber Thiago de Oliveira, Eduardo Maffud Cilli, Carla Raquel Fontana

Year

2018

Journal

Scientific Reports

Abstract

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.

Instrument

J-715

Keywords

Circular dichroism, Secondary structure, Chemical stability, Vesicle interactions, Biochemistry