Trichophyton eboreum– A recently described dermatophyte

Keratinophilic and Keratinolytic Fungi in Cave Ecosystems: A Culture-Based Study of Brestovská Cave and Demänovská Ľadová and Slobody Caves (Slovakia)

Despite speleomycological research going back to the 1960s, the biodiversity of many specific groups of micromycetes in underground sites still remains unknown, including keratinolytic and keratinophilic fungi. These fungi are a frequent cause of infections in humans and animals. Since subterranean ecosystems are inhabited by various animals and are a great tourist attraction, the goal of our research was to provide the first report of keratinophilic and keratinolytic fungal species isolated from three caves in Tatra Mts., Slovakia (Brestovská, Demänovská Ľadová and Demänovská Slobody). Speleomycological investigation was carried out inside and outside the explored caves by combining culture-based techniques with genetic and phenotypic identifications. A total of 67 fungal isolates were isolated from 24 samples of soil and sediment using Vanbreuseghem hair bait and identified as 18 different fungal species. The study sites located inside the studied caves displayed much more fungal species (17 species) than outside the underground (3 species), and the highest values of the Shannon diversity index of keratinophilic and keratinolytic fungi were noted for the study sites inside the Demänovská Slobody Cave. Overall, Arthroderma quadrifidum was the most common fungal species in all soil and/or sediment samples. To the best of our knowledge, our research has allowed for the first detection of fungal species such as Arthroderma eboreum, Arthrodermainsingulare, Chrysosporiumeuropae, Chrysosporiumsiglerae, Keratinophytonwagneri, and Penicillium charlesii in underground sites. We also showed that the temperature of soil and sediments was negatively correlated with the number of isolated keratinophilic and keratinolytic fungal species in the investigated caves.

Cutaneous hyalohyphomycosis due to Parengyodontium album gen. et comb. nov

"Engyodontium album" is an environmental saprobic mould and an emerging opportunistic pathogen able to cause both superficial and systemic infections. In this study, we isolated a mould from the skin lesion biopsy specimen of the right shin in a patient who received renal transplantation for end-stage renal failure with prednisolone, tacrolimus, and azathioprine immunosuppressant therapy. Histology of the skin biopsy showed mild squamous hyperplasia and neutrophilic infiltrate in the epidermis, active chronic inflammation in the dermis, and fat necrosis in the subcutis, with numerous fungal elements within the serum crusts. On Sabouraud glucose agar, the fungus grew as white, cobweb-like, floccose colonies. Microscopically, conidiogenous cells were arranged in whorls of one to seven at wide angles, with zigzag-shaped terminal fertile regions and smooth, hyaline, oval, apiculate conidia. DNA sequencing showed the mould isolate belonged to "E. album" but matrix-assisted laser desorption ionisation-time of flight mass spectrometry (MALDI-TOF MS) failed to identify the isolate. Phylogenetic analyses based on the internal transcribed spacer region, 28S nuclear ribosomal DNA, and β-tubulin gene and MALDI-TOF MS coupled with hierarchical cluster analysis showed that "E. album" is distantly related to other Engyodontium species and should be transferred to a novel genus within the family Cordycipitaceae, for which the name Parengyodontium album gen. et comb. nov. is proposed. Three potential cryptic species within this species complex were also revealed. Antifungal susceptibility testing showed posaconazole and voriconazole had high activities against all clinical P. album isolates and may be better drug options for treating P. album infections.

Isolation of dermatophytes (and other fungi) from human nail and skin dust produced by podiatric medical treatments in Australia

BACKGROUND

Podiatric physicians routinely use electric drills for the treatment of nail and skin conditions. The grinding process produces human nail and skin dust that is generally vacuumed into bags in the grinding unit. Many of the nails are thought to be mycotic, particularly because they are obtained from patients with symptoms of dermatophyte infections. Currently, there is limited information available on the detection of fungi from nail dust samples. Herein, we attempt to address this situation and outline some of the difficulties that pathology laboratories face in isolating and identifying dermatophytes from nail samples.

METHODS

Fifty nail dust bags from podiatric medical clinics across all of the states and territories of Australia were collected and analyzed. Samples from the bags were inoculated onto primary isolation media. Fungal colonies that grew were then inoculated onto potato dextrose agar for identification using standard morphological (macroscopic and microscopic) features.

RESULTS

One hundred fifty-one colonies of dermatophytes were identified from 43 of the 50 samples. In addition 471 nondermatophyte molds were isolated, along with some yeasts and bacteria.

CONCLUSIONS

The most common dermatophytes isolated were from the Trichophyton mentagrophytes/interdigitale complexes. Trichophyton rubrum, Trichophyton tonsurans, Trichophyton soudanense, and Epidermophyton floccosum were also isolated. An unidentified group of dermatophytes was also present. The three most common genera of nondermatophyte molds were Aspergillus, Penicillium, and Scopulariopsis, all of which have been implicated in onychomycosis and more general disease. The presence of viable fungal pathogens in the dust could potentially pose a health problem to podiatric physicians.