Identification of molecular and metabolic markers of persister cells isolated from Cryptococcus neoformans and Cryptococcus gattii biofilms

• Grant number: 24/23541-1
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: June 01, 2025
• End date: February 28, 2029
• Field of knowledge: Health Sciences - Pharmacy
• Principal Investigator: Ana Marisa Fusco Almeida
• Grantee: Gabriel Rezende Pimenta
• Host Institution: Faculdade de Ciências Farmacêuticas (FCFAR). Universidade Estadual Paulista (UNESP). Campus de Araraquara. Araraquara , SP, Brazil

Abstract

Cryptococcus neoformans and Cryptococcus gattii are the encapsulated yeasts that cause cryptococcosis. Cryptococcosis is a systemic fungal disease characterized by affecting immunocompromised (mainly C. neoformans) and immunocompetent (mainly C. gattii) individuals, affecting the lower respiratory tract and often later, the central nervous system. Antifungal treatment is aggressive, toxic, and can be ineffective. In this context, resistance to antifungal drugs makes it difficult to treat these infections, especially in immunocompromised patients. Among the resistance factors of fungi, efflux pumps, changes in the target enzyme, biofilms and persister cells stand out. The objective of this project is to evaluate the molecular mechanisms of resistance and identify specific molecular markers in the metabolic transition periods proposed for C. neoformans and C. gattii persister cells, for the mapping of multiple targets and molecular characterization of these cells. The methodology will address: (1) culture of microorganisms; (2) Formation of biofilms of both species; (3) recovery and identification of persister cells; (4) Confocal laser scanning microscopy of persister cells; (5) Genomic sequencing of persister, planktonic and biofilm cells; (6) Transcriptomic sequencing of persister, planktonic and biofilm cells; (7) identification, functional categorization and localization of protein domains; (8) Quantification of the expression of target genes of persister cells; (9) Susceptibility tests.