Polyphasic Taxonomy of Species within the Dermatophyte Genus Arthroderma Including A. fimbriatum sp. nov and A. cellare sp. nov.

Arthroderma is a taxonomically diverse genus within the dermatophyte family (Onygenales, Arthrodermataceae) comprising primarily geophilic species typically found in animal burrows, where they feed on keratinous debris. In this study, species delineations within the genus were refined according to current taxonomic standards using the extensive array of Arthroderma strains of the BCCM/IHEM fungi collection. The methodology was based on a polyphasic approach including phenotypic analyses, multi-gene phylogenetic inference (comprising the internal transcribed spacer (ITS), β-tubulin (BT), and RNA polymerase II core subunit (RBP2) regions) and MALDI-TOF mass spectrometry. Special attention was given to the highly diverse A. quadrifidum clade which contains both geophilic and potentially zoophilic species, assessing the phylogenetic position of recently described taxa within this group. In total, 77 strains from the BCCM/IHEM collection were (re-)examined. MALDI-TOF mass spectrometry was able to correctly identify 92% of the strains at species level. Additionally, certain isolates did not correspond to any previously described taxa, leading to the recognition, description and typification of two novel species.