Mechanistic study of the photosensitization of Candida and Trichophyton species

• Grant number: 12/22933-6
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: March 01, 2013
• End date: February 29, 2016
• Field of knowledge: Biological Sciences - Microbiology - Applied Microbiology
• Principal Investigator: Gilberto Úbida Leite Braga
• Grantee: Gabriela Braga Rodrigues
• Host Institution: Faculdade de Ciências Farmacêuticas de Ribeirão Preto (FCFRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil

Abstract

Fungal species of the genera Candida and Trichophyton are responsible for most of the mycoses in humans. The increasing emergence of fungicide tolerance among many species of pathogenic fungi has stimulated the development of different approaches to control this group of pathogens. Antifungal photodynamic treatment (APDT) is a promising alternative to conventional fungicides. The process involves the use of a non-toxic light activate photosensitizer (PS) which selectively accumulates into the target-cells. In the presence of oxygen, the excited state PS induces the formation of several reactive oxygen species that kill the microorganism without significant damage to the host. Although very promising, the use of APDT to treat mycosis has not been much developed. The objectives of the present study are: (1) to identify novel PS more effective for the treatment of localized mycosis in humans caused by species of the genera Candida and Trichophyton; (2) to determine the mechanism of action of the novel PS in metabolically active structures such as hyphae and yeast cells as well as in quiescent structures such as conidia, and (3) to evaluate and characterize the damage of the photodynamic treatment with the novel PS on cells of the fungal hosts. The expected contributions include the improvement of the efficacy of APDT for the treatment of human mycosis and the improvement of the mechanistic understanding of APDT with the novel PS on the specialized structures of the different fungal species and on the host cells.

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

RODRIGUES, GABRIELA BRAGA; PINTO, MARCELO RODRIGUES; LEITE BRAGA, GILBERTO UBIDA. Photodynamic inactivation of Candida albicans and Candida tropicalis with aluminum phthalocyanine chloride nanoemulsion. FUNGAL BIOLOGY, v. 124, n. 5, p. 297-303, MAY 2020. (12/22933-6, 12/15204-8, 16/11386-5, 18/20571-6)

RODRIGUES, GABRIELA BRAGA; PEREIRA BRANCINI, GUILHERME THOMAZ; UYEMURA, SERGIO AKIRA; BACHMANN, LUCIANO; WAINWRIGHT, MARK; LEITE BRAGA, GILBERTO UBIDA. Chemical features of the photosensitizers new methylene blue N and S137 influence their subcellular localization and photoinactivation efficiency in Candida albicans. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY, v. 209, AUG 2020. (12/15204-8, 12/22933-6, 15/24305-0)