Rare malbranchea-like fungal isolates from clinical specimens in United States of America.

This is the authors' abstract. We don't add key points for this paper.

The fungi of the order Onygenales can cause important human infections; however, their taxonomy and worldwide occurrence is still little known. We have studied and identified a representative number of clinical fungi belonging to that order from a reference laboratory in the USA. A total of twenty-two strains isolated from respiratory tract (40 %) and human skin and nails (27.2 %) showed a malbranchea-like morphology. Six genera were phenotypically and molecularly identified, i.e. Auxarthron/Malbranchea (68.2 %), Arachnomyces (9.1 %), Spiromastigoides (9.1 %), and Currahmyces (4.5 %), and two newly proposed genera (4.5 % each). Based on the results of the phylogenetic study, we synonymysed Auxarthron to Malbranchea, and erected two new genera: Pseudoarthropsis and Pseudomalbranchea. New species are proposed: Arachnomyces bostrychodes, A. graciliformis, Currahmyces sparsispora, Malbranchea gymnoascoidea, M. multiseptata, M. stricta, Pseudoarthropsis crassispora, Pseudomalbranchea gemmata and Spiromastigoides geomyces, along with a new combination for Malbranchea gypsea. The echinocandins showed the highest in vitro antifungal activity against the studied isolates, followed by terbinafine and posaconazole; in contrast, amphotericin B, fluconazole, itraconazole and 5-fluorocytosine were less active or lacked in vitro activity against these fungi.