Dermatophytes and other members of Onygenales are unique in their ability to degrade keratin, affecting hair and nails, and in case of human hosts cause infection of the skin. Subtillisins are essential proteases in keratin assimilation, and subtilisin-like protease 1 (SUB1) and SUB3–7 are specific for dermatophytes. eIF2α kinases are serine-threonine kinases that perform essential functions in response to infection, proteotoxicity, and nutrient scavenging. The relatively conserved nature of EIF2AK4 among fungi makes them potential evolutionary markers, which may contribute to a deeper understanding of dermatophyte taxonomy and evolution. The aim of the present study was to evaluate the phylogeny of dermatophytes using EIF2AK4 and SUB1 genes, compared to ITS evolution. The EIF2AK4 tree had a similar topology to the SUB1 tree, and both deviated from the ITS gold standard by evolution. Our preliminary findings with a limited dataset suggest that the EIF2AK4 and SUB1 genes provide a reasonably correct reflection of the evolution of Arthrodermataceae. In addition, the study analyzed in vitro keratinolytic responses of 19 dermatophyte species using hairs of a broad selection of mammals as substrates. Trichophyton mentagrophytes and Nannizzia gypsea were the most active in degrading hair, while Trichophyton verrucosum, Trichophyton tonsurans and Epidermophyton floccosum showed low response. Hairs of Hyracoidea and Rodentia were most affected of all mammal hairs, while in contrast, bat hairs were difficult to degrade by nearly all tested dermatophyte species. Zoophilic species showed more activity than anthropophilic dermatophytes, but hair degradation profiles were not diagnostic for particular dermatophyte species.
S5.4 Free oral paper session, September 22, 2022, 3:00 PM - 4:30 PM Objectives Analysis of the cutaneous manifestations in patients with deep fungal infections to provide a basis for clinical differentiation and diagnosis. Method: Patients who presented to our hospital from 2016 to 2021, were definitively diagnosed with deep fungal infections by histopathology and mycological detection. Isolates of focal infections were cultured in vitro on SDA or MEA media for 14 days and the species were identified by morphological or molecular analysis. Relevant clinical data on epidemiologic, skin manifestations, underlying disease, causative fungal agent, treatment, and outcomes are collected and analyzed. Results A total of 15 patients were diagnosed with deep fungal infections. The respiratory system (7/15) was the most easily involved primary focus of deep fungal infection, digestive system (3/15), and nervous system (2/15) were less common. The mean age of the patients was 50.30 years. Of these, 8 were males. More than half of the cases (7/15) were presented in immunosuppressed patients, including long-term glucocorticoid use, organ transplantation, tuberculosis infection, and malignancy. Skin manifestations were varied, with plaques (5/15) being the most common type of lesion, and then papules (4/15), nodules (2/15), patches (2/15), and ulcers (2/15). Candida spp. (9/15) was the most common pathogens, followed by Talaromyces marneffei (2/15) (Fig. 1a), Cryptococcus spp. (2/15) (Fig. 1b), and Aspergillus spp. (2/15). One case had co-infection with C. albicans and Aspergillus spp. Conclusions: Patients with deep fungal infections are often accompanied by skin manifestations, which vary between patients with deep fungal infections caused by different pathogenic fungi.
Poster session 2, September 22, 2022, 12:30 PM - 1:30 PM Objective: We present ten tinea incognito (TI) patients caused by Trichophyton rubrum combined with a review of the characteristics of tinea incognito infections reported worldwide over the past 20 years, leading to clinical requirements for diagnosis and treatment. Patients and Methods: Patients were scraped for direct KOH microscopy of the skin lesions at the initial visit, isolates were cultured in SDA medium for 14 days and species were identified by morphology and molecular analysis using ITS regions. Literature review by searching articles on ‘PubMed’ and ‘Web of Science’, using the keywords ‘Tinea incognito or Incognito’, Set the year as ‘2002-2022’, and screened the literature for cases with clear types of TI infecting pathogens. Clinical, mycological, and treatment data of all cases were collected and analyzed. Results We report 10 cases of tinea incognito caused by T. rubrum, ranging in age from 5 to 70 years, with clinical manifestations of eczema-like (Figs. 1a, b, and f), SLE-like (Fig. 1d) and pustular psoriasis-like (Figure 1c, e, g, h, i and j), seen in multiple sites. All of our patients had either tinea pedis or onychomycosis themselves or in their family members. A total of 660 cases reported in the last 20 years, T. rubrum (279/660) was the main anthropophilic dermatophytes causing TI, T. mentagrophytes (162/660) and Microsporum canis (135/660) were the common zoophilic pathgens. There were median age differences in patients infected with T. rubrum, T. mentagrophytes, M. canis, and Nannizzia gypsea, at 56, 22.5, 23, and 5.5 years old, respectively (Fig. 2a). The TI patients infected by T. rubrum often had cutaneous or non-cutaneous underlying diseases (27/41), TI patients with zoophilic or geophilic dermatophyte infections had a definite animal or soil contact history (114/136). The face and trunk are the most frequently affected areas, followed by the extremities and the whole body (Fig. 2b). TI appears on the face and is often thought of as eczema, rosacea, DLE, photosensitive rash, and when it occurs on the trunk is misdiagnosed as eczema, pyoderma, psoriasis (Fig. 2c). In Asia and the Americas, anthropophilic dermatophytes are by far the most reported pathogens, especially T. rubrum. In Europe, zoonotic pathogens have been reported in excess of the anthropophilic (Fig. 2d). For patients in whom the nature of the lesions cannot be determined and with negative direct microscopic examination, dermoscopy can be used to aid in the diagnosis. Our review of all cases found that topical or systemic antifungal treatment always gave good efficacy. Conclusion TI has a broad spectrum of mimics, and an unrestricted range of target audiences, zoonotic pathogens are adapting to the human host, so the history of illness and contact is essential at the time of the initial visit. A definitive diagnosis must be obtained in a mycological laboratory, multiple modalities can be used to diagnose TI, and systemic antifungal treatment is often necessary.
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