Phylogeny and taxonomy of the family Arthrodermataceae (dermatophytes) using sequence analysis of the ribosomal ITS region

The internal transcribed spacer (ITS) region, covering the ITS1, ITS2 and 5 .8S ribosomal DNA was used to evaluate phylogenetic relationships within th e fungal family Arthrodermataceae. Sequences of variable length, ranging be tween 522 and 684 base pairs were aligned. An unrooted consensus tree based on parsimony analysis showed Trichophyton to be polyphyletic, and Microspo rum to be para phyletic. Non-monophyly of these two genera is in conflict w ith traditional classification. But this relation is not strongly supported by bootstrap analysis. Phylogenetic analysis showed that the two known mem bers of the genus Epidermophyton grouped widely apart from each other. With in Trichophyton, our results suggest a separation of human pathogenic speci es and primarily geophilic species. Bootstrap support for these two groups is fairly high and both groups are recognized by current taxonomy, Three li neages were revealed within the T. mentagrophytes species complex. Microspo rum canis, M. audouinii and M. equinum were found to be closely related. Th e topology of the tree was robust to various methods of analysis (parsimony and distance) and a different weighting scheme. Weighting of transversions over transitions did not improve the status of poorly supported branches o f the tree.