Resumo

Introduction: The incidence of systemic fungal diseases in both healthy subjects and in immunocompromised shows an increasing pattern in the whole world in recent years, transforming the fungal disease in an important field of medical research. Paracoccidioidomycosis (PCM) is a systemic granulomatous disease caused by the dimorphic fungi Paracoccidioides complex (P.brasiliensis and P.lutzii). This mycoses is of great importance in our country, given its frequency, in Brazil represents 80% of reported cases occurred in patients in the Southeast and South regions, specifically in Sao Paulo, Minas Gerais, Paraná and Rio Grande do Sul. One of the strategies possibly used by the pathogen, would be the expression of genes involving adaptations to the host, can also be related to the formation of biofilm and thus become difficult to eliminate infection. Biofilms represent the predominant type of microbial growth in nature and are crucial in the development of infections once serving to niche pathogens and are associated with high levels of resistance to antimicrobials. Objective: The aim of this study was to investigate the ability of P. brasiliensis biofilm formation. Material/ Methods: P. brasiliensis biofilm assays were performed in vitro using P. brasiliensis (Pb 18), FUM medium (with modifications) and a low oxygen tension (10% CO2). Biofilms were characterized using scanning electron microscopy (SEM) and Confocal Laser Scanning Microscopy (CLSM) and were measured using a 2.3-bis(2-methoxy-4-nitro-5-sulfophenyl)-5-[(phenylamino)carbonyl]-2H-tetrazolium-hydroxide (XTT) reduction assay. Results: The result showed that P. brasiliensis (Pb18) was very efficient to form biofilm. The kinetics showed that the Pb 18 strain produced a strong biofilm in the period from 120 to 144 hours and three-dimensional image of the sections showed biofilm with thickness of 60 µm. The metabolic activity of biofilm was increased with increasing cell mass. Conclusion: This is a possible survival strategy adopted by this fungus.