Two Trichosporon species isolated from Central-European mygalomorph spiders (Araneae: Mygalomorphae)

Trichosporon (Dikarya: Basidiomycota) is a genus of anamorphic yeasts typically associated with soil and water, although many species are causative agents of diseases in animals and man. Here we provide the first compelling evidence that spiders can be occasionally colonized by at least two Trichosporon species. Trichosporon dulcitum (Berkhout) Weijman 1979 was isolated from the exoskeleton of purse-web spider Atypus piceus, while Trichosporon porosum (Stautz) Middelhoven, Scorzetti & Fell 2001 was isolated from the exoskeleton of purse-web spider Atypus affinis. Both of the species were identified based on DNA sequence analysis of the host specimens displaying macroscopic signs of the superficial white mycosis on their exoskeleton. Only two specimens with macroscopic signs of superficial yeast growth were identified among the 125 individuals of A. affinis, A. piceus and Atypus muralis examined that were collected at various sites throughout the Czech Republic. The consistent burrow microclimate, uninterrupted occupancy of the single burrow for several subsequent years, and presence of prey remnants in the burrow below the purse-web may play a role in the course of infection of the mygalomorphs examined. The phylogenetic relationships of Trichosporon species are analyzed, concluding that association with invertebrates clusters predominantly among four groups of closely related species in independent Trichosporon clades.