CHARACTERIZATION OF Trichophyton spp. BIOFILM

Onychomycosis is a chronic infection of fungal origin that involves the nails, is part of the dermatomycosis group and is a frequent disorder in the population and is estimated to correspond to 50% of all onychopathies. Among these agents, dermatophytes are the most frequent, identified in up to 90% of nail onychomycosis and 50% of nails of the hands. Recently it has been shown that onychomycosis was a result of the organization of the fungus in the form of biofilm. This property would explain the chronic character and the difficulty of control and cure of onychomycosis. In addition, the fact that fungi are strongly adhered to nails and that onychomycosis can be caused by more than one fungus, reinforce this idea as they are common features in biofilm. Being in complex microbial communities, these fungi are given a greater resistance when compared in their planktonic form, due to the extracellular matrix constituted of polymeric substances produced by the fungus itself. Thus, it may be related to the persistent infection, therapeutic and long-term resistance to the cure of onychomycosis. Therefore, this work aimed to characterize the biofilm formation potential of Trichophyton rubrum and T. interdigitale from clinical specimens. Two clinical isolates from onychomycosis were evaluated, identified as T. rubrum CMRP2912 and T. interdigitale CMRP2921 belonging to the fungal collection of Medical Mycology Laboratory, Education and Research Laboratory of Clinical Analysis (Lepac / UEM) opposite the ability to form biofilms (24, 48 and 72 hours) on polystyrene microplate, quantified by Colony Forming Units (CFU), by Crystal Violet coloration (CV) and by reduction of tetrazolium salt (XTT). The clinical isolates used in this study formed biofilm after 24, 28 and 72 hours of incubation. The results show that the initial metabolic activity of biofilms is increasing by 24-48h, showing a significant increase in the metabolism in activity for both species. After 72 hours, biofilms maintain metabolic activity and are considered mature. These results with Trichophyton spp. corroborate with a series of studies that are being carried out to explain onychomycosis as a biofilm. Although Trichophyton spp. have a low virulence profile, they cause chronic infections and present great difficulties in the treatment, being mainly due to the capacity to form biofilm.