Clinical and environmental isolates of Trichosporon spp.: characterization, virulence research and profile of susceptibility to antifungals

Abstract

Trichosporon spp. are widely distributed in nature, comprising several species that inhabit different ecological niches. They can be found in water, soil and body surface of animals. In humans, this fungal species occasionally finds itself as a member of the gastrointestinal microbiota and oral cavity and, temporarily, they can colonize the respiratory tract and skin. This microorganism has been classically associated with superficial infections. However, in the last decades, it is also related to infections that are disseminated in immunocompromised patients. Aiming to increase the knowledge about this pathogen this work will have as objectives: re-identify phenotypically, genotypically and by mass spectrometry yeasts of the genus Trichosporon of clinical origin (human and animal) and environmental kept in fungi collection; to determine and compare factors related to virulence of yeasts of the genus Trichosporon of clinical (human and animal) and environmental origin: production of the phospholipase, proteinase enzymes; to determine and compare the ability of yeasts of the genus Trichosporon of clinical origin (human and animal) and environmental to form biofilm; to evaluate the biofilm susceptibility patterns of certain antifungal agents; to evaluate the susceptibility patterns of the isolates against antifungals comparing the microdilution techniques in broth and Etest; to characterize and to compare the genotypic diversity and to perform phylogenetic analysis of the isolates identified as Trichosporon asahii of clinical (human and animal) and environmental origin; to study the antifungal genotype-susceptibility association, evaluating whether the genetic diversity of T. asahii isolates is associated with different antifungal behaviors tested in the study. (AU)