Investigation of genes encoding efflux pumps in biofilms and persisters cells of Cryptococcus neoformans and Cryptococcus gattii

• Grant number: 23/11855-9
• Support Opportunities: Scholarships in Brazil - Master
• Start date: January 01, 2024
• End date: December 31, 2024
• 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 clinically characterized by affecting immunocompromised (C.neoformans) and healthy (C.gattii) individuals, affecting the lower respiratory tract and subsequently the central nervous system (CNS). Antifungal treatment is aggressive, toxic, and can be ineffective. In this context, resistance to antifungal drugs makes unaccompanied treatment difficult, especially in immunocompromised patients. Among the fungi resistance switches, the formation of biofilms and the production of efflux pumps (transmembrane proteins) stand out. Some factors have been proposed for the resistance of biofilms to antifungal agents, such as: drug sequestration by matrix components, upregulation of drug efflux pumps and the presence of persisters cells (persistent; tolerant). Genes of antifungal efflux pumps in biofilms and persisters cells of C. neoformans and C. gattii will be evaluated for the design of new specific targets for resistant strains arising from these biofilms. The methodology will address: the comparative evaluation of the quantitative expression of the genes of efflux pumps AFR1, AFR2, AFR3, PDR6, MDR1, CDR1 and CDR2 in the kinetics of biofilm formation (with and without efflux pump inhibitors) and in persisters cells ( with and without antifungals), using RT-qPCR; the characterization of the matrixiome (total components of the extracellular matrix) in the kinetics of formation of these biofilms with and without the selected inhibitors, comparing the phenotypes of the two species; the induction, identification and evaluation of the minimum inhibitory concentration of persisters cells.