A New Genus of Myriangiales Order Isolated from a Toenail

Clarifying the phylogenetic positions of microorganisms is a primary area of expertise of microbial culture collection centers. In the present study, we aimed to elucidate the phylogenetic position of a fungal strain, previously reported from a human toenail. The earlier report was able to resolve its phylogeny only until genus level (Elsinoë). After being deposited in KACC as strain KACC 410304, a comprehensive examination was conducted which included studying its morphological features as well as sequences of the internal transcribed spacer (ITS), large subunit (LSU), partial translation elongation factor 1-alpha (TEF1-α) and partial DNA-directed RNA polymerase II second LSU (RPB2) to resolve its taxonomic position. Morphological and microscopic observations indicated colonies to be slow-growing, grayish sepia on potato dextrose agar, apricot to brown color on malt extract agar and produce enteroblastic, monophialidic, hyaline, smooth to verruculose, ampulliform to doliiform conidiogenous cells. Conidia were hyaline, granular, aseptate, guttulate, ellipsoid to oblong, apex obtuse, and club shaped. Maximum-likelihood phylogenetic tree based on the combined four nuclear markers (ITS, LSU, TEF1-α, and RPB2) revealed that the strain grouped within the order Myriangiales and formed an independent lineage. Therefore, we propose that the strain does not fall under family Myriangiaceae or Elsinoaceae, but separates into a distinct clade within the order Myriangiales. We describe here Cerebroclavomyces unguium gen nov. et sp. nov. as incertae sedis within Myriangiales using KACC 410304 as its ex-type culture.