Mechanisms of action of antimicrobial peptides ToAP2 and NDBP-5.7 against Candida albicans planktonic and biofilm cells

Sci Rep. 2020 Jun 25;10(1):10327. doi: 10.1038/s41598-020-67041-2.

Abstract

Candida albicans is a major cause of human infections, ranging from relatively simple to treat skin and mucosal diseases to systemic life-threatening invasive candidiasis. Fungal infections treatment faces three major challenges: the limited number of therapeutic options, the toxicity of the available drugs, and the rise of antifungal resistance. In this study, we demonstrate the antifungal activity and mechanism of action of peptides ToAP2 and NDBP-5.7 against planktonic cells and biofilms of C. albicans. Both peptides were active against C. albicans cells; however, ToAP2 was more active and produced more pronounced effects on fungal cells. Both peptides affected C. albicans membrane permeability and produced changes in fungal cell morphology, such as deformations in the cell wall and disruption of ultracellular organization. Both peptides showed synergism with amphotericin B, while ToAP2 also presents a synergic effect with fluconazole. Besides, ToAP2 (6.25 µM.) was able to inhibit filamentation after 24 h of treatment and was active against both the early phase and mature biofilms of C. albicans. Finally, ToAP2 was protective in a Galleria mellonella model of infection. Altogether these results point to the therapeutic potential of ToAP2 and other antimicrobial peptides in the development of new therapies for C. albicans infections.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amphotericin B / pharmacology
  • Amphotericin B / therapeutic use
  • Animals
  • Antifungal Agents / pharmacology*
  • Antifungal Agents / therapeutic use
  • Biofilms / drug effects*
  • Candida albicans / drug effects*
  • Candidiasis / drug therapy*
  • Candidiasis / microbiology
  • Cell Membrane Permeability / drug effects
  • Cell Wall / drug effects
  • Disease Models, Animal
  • Drug Resistance, Fungal
  • Drug Synergism
  • Drug Therapy, Combination / methods
  • Fluconazole / pharmacology
  • Fluconazole / therapeutic use
  • Humans
  • Microbial Sensitivity Tests
  • Moths
  • Pore Forming Cytotoxic Proteins / pharmacology*
  • Pore Forming Cytotoxic Proteins / therapeutic use

Substances

  • Antifungal Agents
  • Pore Forming Cytotoxic Proteins
  • Amphotericin B
  • Fluconazole