Molecular identification of yeasts from the order Trichosporonales causing superficial infections

Abstract

BackgroundThe molecular reclassification of the order Trichosporonales placed the medically relevant Trichosporon species into three genera of the family Trichosporonaceae: Cutaneotrichosporon, Trichosporon, and Apiotrichum. From the clinical and epidemiological standpoint, it is important to identify any species of the family Trichosporonaceae because they present different antifungal susceptibility profiles. In Mexico, little is known about trichosporonosis etiology because the fungi are identified through phenotypic methods. AimsTo identify at a molecular level 12 yeast isolates morfologically compatible with Trichosporon, obtained from patients with superficial infections. MethodsThe yeast isolates were obtained from patients with white piedra, onychomycosis, and hand and foot dermatomycosis, and were identified morphologically and genotypically (sequencing of the IGS1 region and phylogenetic analysis using the Maximum Likelihood Method). The phylogenetic analysis included 40 yeast sequences from the order Trichosporonales and one from Cryptococcus neoformans as outgroup. ResultsBased on the molecular analysis, we identified three (25%) Trichosporon inkin isolates, two (16.7%) Trichosporon asteroides, two (16.7%) Cutaneotrichosporon mucoides, and one each (8.3%) of Trichosporon aquatile, Trichosporon asahii, Apiotrichum montevideense, Cutaneotrichosporon cutaneum, and Cutaneotrichosporon jirovecii. ConclusionsThe molecular characterization of the isolates showed a broad diversity of species within the order Trichosporonales, particularly among onychomycosis. It is essential to identify these yeasts at the species level to delve into their epidemiology.