Biofilm formation by Candida albicans is inhibited by photodynamic antimicrobial chemotherapy (PACT), using chlorin e6: increase in both ROS production and membrane permeability
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Candida albicans is an opportunistic fungal producing both superficial and systemic infections in immunocompromised patients. Furthermore, it has been described an increase in the frequency of infections which have become refractory to standard antifungal therapy. Photodynamic antimicrobial chemotherapy (PACT) is a potential antimicrobial therapy that combines visible light and a nontoxic dye, known as a photosensitizer, producing reactive oxygen species (ROS) that can kill the treated cells. The objective of this study was to investigate the effects of PACT, using chlorin e6, as a photosensitizer on C. albicans. In this work, we studied the effect of PACT on both cell growth and biofilm formation by C. albicans. In addition, both ROS production and cell permeability were determined after PACT. PACT inhibited both growth and biofilm formation by C. albicans. We have also observed that PACT increased both ROS production (six times) and cell membrane permeability (five times) in C. albicans. PACT decreased both cell growth and biofilm development. The effect of PACT using chlorin e6 on C. albicans could be associated with an increase in ROS production, which could increase cell permeability, producing permanent damage to the cell membranes, leading to the cell death.
KeywordsPhotodynamic antimicrobial chemotherapy PACT Candida albicans Chlorin e6
This work was supported by Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) and Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq).
Role of funding source
The authors would like to thank FAPESP for the financial support.
Compliance with ethical standards
Conflict of interest
The authors have no financial, personal, or other conflicts of interest related to this work.
In this study, all experiments were performed using cultures of Candida albicans (ATCC 10231), therefore, it is not necessarily approved by local authorities.
We have obtained permission from all the authors. We declare that the material has not been published in whole or in part elsewhere; the paper is not currently being considered for publication elsewhere.
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