Pedro Paulo Rodrigues Colares¹, Brendda Miranda Vasconcelos¹, Maria Laína Silva¹, Lua Silva¹, Rossana de Aguiar Cordeiro¹

Environmental contamination by microplastics is a contemporary challenge, with growing evidence of their presence in human tissues, organs, and fluids. The surface of these polymers, by forming a niche called the "plastisphere" can serve as a vector for pathogenic microorganisms or modulate their pathogenicity. Yeasts of the Candida genus, important opportunistic pathogens, are recognized for their ability to form biofilms on abiotic surfaces. However, the consequences of the interaction between microplastics and the virulence of Candida species are poorly understood. This study aims to investigate the interference of polystyrene microplastics in biofilm formation and antifungal susceptibility in C. albicans and C. parapsilosis. To this end, biofilms of both species were developed in the presence and absence of polystyrene microplastics for 48 hours. Biomass was quantified using the crystal violet method, and the susceptibility of mature biofilms to the antifungal agents fluconazole, voriconazole, amphotericin B, and caspofungin was evaluated. Preliminary results indicated that exposure to microplastics significantly increased (p<0.01) biofilm biomass in both species. Additionally, biofilms formed in the presence of microplastics showed a significant increase in resistance to all tested antifungals. These findings suggest that polystyrene microplastics can modulate yeast biofilm formation and their resistance profile. Therefore, a thorough investigation of the molecular mechanisms involved in this interaction is necessary. In this regard, a proteomic approach is essential to elucidate the changes in adhesion proteins, extracellular matrix components, and drug resistance mechanisms, such as efflux pumps.

Agradecimentos: The authors acknowledge the Laboratory of Infectious Bioagents and the Federal University of Ceará for the infrastructural support, and their colleagues for the collaborative atmosphere. This research was supported by the National Council for Scientific and Technological Development (CNPq), whose funding was essential to carry out this work.