International partnership for the evaluation of genetic heterogeneity of Trichosporon sp. clinical isolates and impact on taxonomy, biology and species identification

Abstract

Intraspecific diversity described in different levels of biological organization is a relevant topic in the scientific debate, and an important element in understanding that how gene flow can impact in process of adaptation, speciation and phenotypic plasticity in human pathogens. The taxonomy of the genus Trichosporon has been extensile studied. Currently, includes 12 species: T. asahii is a predominant species, however, the isolation of T. faecale and T. asteroides in invasive infections has drawn attention. Despite the genetic heterogeneity described for T. asahii (15 genotypes) and T. faecale (3 genotypes), the biological relevance of this variability is still unclear. With the collaboration of Trichosporon Brazil Network, more than 600 clinical isolates were collected. In this collection, five genotypes of T. asahii (1,3,4,5,7), and 2 of the 3 genotypes of T. faecale (1,3) were found, and the characterization of genotypes not yet described for T. asteroides. Based on these results, we established an international partnership with the Westerdijk Fungal Biodiversity Institute to explore the biological impact of the genotypes described for Trichosporon sp. using AFLP and sequencing of different loci, as well as to characterize potential peculiarities regarding the susceptibility profile to antifungals and analysis of virulence aspects in Galleria mellonella model. As a result, this project will allow consolidating concepts in the biology and taxonomy of Trichosporon spp., collaborate to the development of molecular diagnostic tests with accuracy, precision, applicability for routine laboratory use, besides allowing the materialization at UNIFESP/EPM of a new line of research in applicable molecular taxonomy to other pathogenic yeasts. (AU)