Deciphering the composition of dermatophyte complexes
In recent years many advances have been made in clearing up the phylogenetic relationships within the family Arthrodermataceae. However, certain closely related taxa still contain poorly resolved species boundaries. Here we try to elucidate the species composition of the Trichophyton rubrum, T. benhamiae species complexes using a combined approach consisting of multi-gene phylogenetic analysis, morphological analysis and spectral comparison. Within the species T. benhamiae we demonstrate the existence of at least 3 species that are distinguishable using common phylogenetic markers ITS and b-tubulin 2, maldi-tof spectrometry and morphological differences. We also confirm that the distinct “yellow” and “white” phenotypes of T.benhamiae do not have a clear genetical basis and should thus be considered varieties. Some lineages within the T. benhamiae complex show minimal but distinct genetical differences to one another while being phenotypically indistinguishable, raising the question where the species boundaries should be drawn in the genomic era. In the T. rubrum complex we show the existence of 4 genetic lineages, each displaying their own distinct morphological and spectral characteristics. ITS and Bt2 genetic markers are, however, not sufficient to acknowledge these lineages as monophyletic species and perhaps other biomolecular techniques should be explored.