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Updated: Sep 26, 2025
Bio-energetics Investigation of Candida albicans Using Real-time Extracellular Flux Analysis
Published on: March 19, 2019
Lack of Functional Trehalase Activity in Candida parapsilosis Increases Susceptibility to Itraconazole
Ruth Sánchez-Fresneda1, María Luz Muñoz-Megías1, Genoveva Yagüe2
1Área de Microbiología, Facultad de Biología, Universidad de Murcia, 30100 Murcia, Spain.
Abstract:
Central metabolic pathways may play a major role in the virulence of pathogenic fungi. Here, we have investigated the susceptibility of a Candida parapsilosis mutant deficient in trehalase activity (atc1Δ/ntc1Δ strain) to the azolic compounds fluconazole and itraconazole. A time-course exposure to itraconazole but not fluconazole induced a significant degree of cell killing in mutant cells compared to the parental strain. Flow cytometry determinations indicated that itraconazole was able to induce a marked production of endogenous ROS together with a simultaneous increase in membrane potential, these effects being irrelevant after fluconazole addition. Furthermore, only itraconazole induced a significant synthesis of endogenous trehalose. The recorded impaired capacity of mutant cells to produce structured biofilms was further increased in the presence of both azoles, with itraconazole being more effective than fluconazole. Our results in the opportunistic pathogen yeast C. parapsilosis reinforce the study of trehalose metabolism as an attractive therapeutic target and allow extending the hypothesis that the generation of internal oxidative stress may be a component of the antifungal action exerted by the compounds currently available in medical practice.
Insights
Investigating a Candida parapsilosis mutant lacking trehalase activity revealed itraconazole, but not fluconazole, effectively kills cells and disrupts biofilms. Trehalose metabolism is a potential antifungal target.
Area of Science:
- Medical Mycology
- Molecular Biology
- Antifungal Drug Discovery
Background:
- Central metabolic pathways are crucial for fungal virulence.
- Trehalose metabolism is a potential target for antifungal therapies.
Purpose of the Study:
- To investigate the susceptibility of a Candida parapsilosis mutant deficient in trehalase activity to azole antifungals.
- To explore the role of trehalose metabolism in azole drug action and biofilm formation.
Main Methods:
- Generating a Candida parapsilosis mutant strain lacking trehalase activity (atc1Δ/ntc1Δ).
- Exposure of mutant and parental strains to fluconazole and itraconazole over time.
- Flow cytometry to assess reactive oxygen species (ROS) production and membrane potential.
- Evaluating biofilm formation in the presence of azole antifungals.
Main Results:
- Itraconazole, but not fluconazole, significantly killed trehalase-deficient mutant cells.
- Itraconazole induced ROS production and increased membrane potential in mutant cells.
- Itraconazole stimulated endogenous trehalose synthesis, unlike fluconazole.
- Azoles impaired biofilm formation, with itraconazole showing greater efficacy.
Conclusions:
- Trehalose metabolism is a promising therapeutic target for treating Candida parapsilosis infections.
- Internal oxidative stress generation may contribute to the antifungal activity of azole compounds.
