Characterization of Virulence Factors, Cellular Stress Response, and Antifungal Susceptibility Testing of Trichosporon spp. Isolated from Northeast Brazilian Patients

<i>Trichosporon</i> spp. are emerging pathogens that may cause high mortality rates, specifically among immunocompromised individuals. The objectives of this study were to perform a phylogenetic analysis of <i>Trichosporon</i> spp. clinical isolates. We also evaluated the expression of different virulence factors in vitro. In addition, the isolates were grown in the presence of cell-wall and membrane stressors. The antifungal susceptibility profiling was determined. The most prevalent strains belonged to the recently described species <i>T. austroamericanum</i>, with 17 isolates. The other strains were identified as follows: <i>T. asahii</i> (n = 4), <i>T. faecale</i> (n = 2), and <i>T. asteroides</i> (n = 2). All the isolates of <i>T. asahii</i>, <i>T. faecale</i>, and <i>T. asteroides</i> were strong biofilm producers. Statistical analysis revealed that <i>T. asahii</i> strains produced more biofilm than <i>T. austroamericanum</i>. Higher cell surface hydrophobicity was also found for <i>T. asahii</i> isolates compared to <i>T. austroamericanum</i> counterparts. <i>T. austroamericanum</i> seems to be more susceptible to Congo Red, Calcofluor White, and SDS than <i>T. asahii</i>. It is possible to conclude that <i>Trichosporon</i> spp. may present peculiarities in terms of the expression of different virulence factors in vitro, besides displaying a variable susceptibility to different cellular stressors. <i>T. faecale</i> isolates may present high MICs to the azoles, while <i>T. asahii</i> against amphotericin B.