A new darkly pigmented and keratinolytic species of Acremonium (Hyphomycetes) with relationship to the Plectosphaerellaceae from human skin and nail lesions in Panama

In a survey of mycotic skin and nail lesions from humans in Chiriqui, Western Panama, a darkly pigmented Acremonium-like fungus was isolated. This hyphomycete has pigmented hyphae, phialides with a conspicuous collarette and forms chlamydospores and one-celled conidia. Growth on hornmeal agar indicates keratinolytic potential of this species. Morphological investigation and phylogenetic analysis based on LSU rDNA and ITS sequences revealed that this species represents an undescribed member of the Plectosphaerellaceae. The species is described as Acremonium collariferum because of its similarities to other Acremonium species and its distinct collarette. Because the strains of this species were isolated from skin and nail lesions, together with dermatophytes and other fungal strains, the pathological impact of Acremonium collariferum is not evident.