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Updated: Aug 10, 2026
Quantifying the Antifungal Activity of Peptides Against Candida albicans
Published on: January 13, 2023
Activity of novel non-amphipathic cationic antimicrobial peptides against Candida species
Lori L Burrows1, Margareta Stark, Celine Chan
1Infection, Immunity, Injury and Repair, Hospital for Sick Children Research Institute, Toronto, ON, Canada. burrowl@mcmaster.ca
Background And Objectives:
Candida species are problematic opportunistic pathogens in the hospital setting, where they are frequently associated with opportunistic infections of indwelling medical devices. There are only a few effective classes of antifungal agents currently available, and some species, such as Candida lusitaniae, Candida glabrata and Candida krusei, are intrinsically resistant to some of these drugs, further reducing existing therapeutic options. We have recently developed synthetic, non-amphipathic cationic antimicrobial peptides (CAPs) based on the structure of native hydrophobic membrane-spanning domains of integral membrane proteins. In this article, we report on the activity of these CAPs and new variants thereof against eight Candida species.
Methods And Results:
Using a combination of MIC, haemolysis, time-kill and biofilm killing assays, we demonstrate activity of CAPs in the micromolar range against eight Candida species, with little toxicity to mammalian cells. The synthetic peptides killed both the fluconazole-susceptible and fluconazole-resistant strains of Candida albicans, Candida tropicalis and C. glabrata by 4 logs or more within 3 h, and also killed pre-formed yeast biofilms on plastic surfaces.
Conclusions:
These peptides show promise as a basis for development of novel, broad-spectrum antimicrobial agents.
Insights
New synthetic cationic antimicrobial peptides (CAPs) show broad-spectrum activity against eight Candida species, including drug-resistant strains. These CAPs effectively kill yeast and biofilms with minimal toxicity to human cells, offering potential for novel antifungal therapies.
Area of Science:
- Antimicrobial peptide research
- Medical mycology
- Drug discovery
Background:
- Candida species are opportunistic pathogens causing hospital-acquired infections, often linked to medical devices.
- Limited antifungal drug options exist, compounded by intrinsic resistance in species like Candida lusitaniae, Candida glabrata, and Candida krusei.
- Synthetic, non-amphipathic cationic antimicrobial peptides (CAPs) were developed based on integral membrane protein domains.
Purpose of the Study:
- To evaluate the antifungal activity of novel synthetic CAPs and their variants against eight Candida species.
- To assess the efficacy of CAPs against both susceptible and resistant Candida strains.
- To determine the safety profile of CAPs concerning mammalian cell toxicity.
Main Methods:
- Minimum Inhibitory Concentration (MIC) assays
- Haemolysis assays
- Time-kill assays
- Biofilm killing assays
Main Results:
- CAPs demonstrated potent activity in the micromolar range against eight Candida species.
- Synthetic peptides effectively killed fluconazole-susceptible and fluconazole-resistant strains of Candida albicans, Candida tropicalis, and Candida glabrata within 3 hours (≥4 log reduction).
- CAPs exhibited low toxicity to mammalian cells and eradicated pre-formed yeast biofilms on plastic surfaces.
Conclusions:
- The synthetic CAPs show significant promise as a foundation for developing new broad-spectrum antimicrobial agents.
- These findings suggest a potential new therapeutic avenue for combating challenging Candida infections.
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