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Background: The T indotineae population shows a high amount of terbinafine resistant isolates based on different point mutations of squalene epoxidase erg1 (ergosterol) gene. A significant proportion of these isolates also show azole resistance., Objectives: Elucidation of the molecular mechanism for azole resistance, especially the identification of mutations in the sterol 14-α demethylase Erg11 genes, which encode for enzymes interacting with azoles., Methods: Sequencing of putative Erg11 genes and analysis of phenotypic resistance pattern using a microplate-laser-nephelometry-based growth assay., Results: Four different types of Erg11B mutants were detected; two double mutants with Ala230Thr/Asp441Gly, respectively, Ala230/Tyr444His and single mutants with Gly443Glu, Tyr444Cys and Tyr444His. All isolates featured the wild type genotype of Erg11A. All strains demonstrated different combinations of Erg1 and Erg11 genotypes., Conclusion: Resistance against terbinafine and azoles developed several times independently within the T indotineae population. The challenge for fungal treatment is, therefore, that species identification is not enough for prediction of therapeutic efficacy of antifungals. In the future, it will also become important to analyse genes involved in resistance mechanisms., (© 2021 The Authors. Mycoses published by Wiley-VCH GmbH.)

Ringworm in cattle may cause an occupational skin disease in humans. Trichophyton verrucosum lead to a highly inflammatory fungal skin infection that is often misdiagnosed as bacterial disease and consequently mistreated with antibiotics. To establish the correct diagnosis, it is necessary to collect skin scales; in addition, a skin biopsy can be helpful. Deep dermatophyte infections by Trichophyton verrucosum can be treated effectively with oral terbinafine. In addition, it is necessary to pay careful attention to use suitable hygiene measures in the stables to protect against reinfection.

Exceedingly virulent pathogens and growing antimicrobial resistances require new therapeutic approaches. The zoophilic dermatophyte Trichophyton benhamiae causes highly inflammatory, cutaneous fungal infections. Recently, it could be shown that the plant-derived alkaloid tryptanthrin (TRP) exhibits strong anti-microbial activities against yeasts and dermatophytes. The aim of this study was to analyse the bioactivity of TRP under infectious conditions using an in-vitro dermatophytosis model employing fibroblasts and keratinocytes infected with T. benhamiae DSM6916. Analyses comprised determination of cell viability, effects on the innate immune response including expression and secretion of pro-inflammatory cytokines/chemokines as well as expression of various antimicrobial peptides (AMP), toll-like receptor (TLR) 2 and proliferation marker MKI67. T. benhamiae caused severe inflammation in the cutaneous cell models. TRP almost fully prevented T. benhamiae-derived damage of dermal fibroblasts and substantially reduced it in epidermal keratinocytes. A distinct down-regulation of the expression and secretion of pro-inflammatory cytokines was observed. Further, TRP promoted AMP expression, especially of HBD2 and HBD3, in keratinocytes even without fungal presence. This study provides crucial evidence that TRP is not only a strong antifungal agent but also potentially modulates the innate immune response. This makes it interesting as a natural antimycotic drug for adjuvant treatment and prevention of fungal re-infection.

The disease burden of chronic-relapsing and therapy-refractory superficial dermatophytosis dramatically increased in India within the past 5-6 years. In order to evaluate the prevalence of this trend, 201 skin scrapings were collected from patients from all parts of India and were tested for dermatophytes using both fungal culture and a PCR-ELISA directly performed with native skin scrapings. Fungal culture material was identified by genomic Sanger sequencing of the internal transcribed spacer (ITS) region and the translation elongation factor (TEF)-1α gene. In total, 149 (74.13%) out of the 201 samples showed a dermatophyte-positive culture result. Out of this, 138 (92.62%) samples were identified as Trichophyton (T.) mentagrophytes and 11 (7.38%) as Trichophyton rubrum. The PCR-ELISA revealed similar results: 162 out of 201 (80.56%) samples were dermatophyte-positive showing 151 (93.21%) T mentagrophytes- and 11 (6.79%) T rubrum-positive samples. In this study, we show for the first time a dramatic Indian-wide switch from T rubrum to T mentagrophytes. Additionally, sequencing revealed a solely occurring T mentagrophytes "Indian ITS genotype" that might be disseminated Indian-wide due to the widespread abuse of topical clobetasol and other steroid molecules mixed with antifungal and antibacterial agents., (© 2018 Blackwell Verlag GmbH.)

Deep trichophytosis is relatively uncommon. The infection of the bearded area is also known as sycosis barbae or tinea barbae and can be caused by various fungal species, most often zoophilic fungi. We report on an 80-year-old male patient with severe sycosis barbae who had no animal contact and was treated with systemic antibiosis without improvement. Microbial and mycological investigations using swabs from oozing lesions revealed Staphylococcus haemolyticus and Candida parapsilosis. Histology demonstrated fungal elements in hair follicles. Paraffin-embedded material was subjected to further mycological analysis. For molecular diagnostics DNA was prepared from paraffin sections for real-time polymerase chain reaction (RT-PCR). For sequencing, DNA was isolated from paraffin-embedded skin tissue and the ITS region of the rDNA was selected. Sequencing of the ITS2 region of rRNA revealed a 100% accordance with Trichophyton (T.) verrucosum. Treatment with oral terbinafine achieved a complete remission. Sycosis barbae is an important differential diagnosis for infections of the bearded area. Nucleic acid amplification techniques (NAAT) are more and more used for direct examination of dermatophytes in clinical samples, eg T. verrucosum. NAAT are also used as culture confirmation tests for identification of rare dermatophytes like T. verrucosum. Today, singleplex and multiplex quantitative real-time PCR (qRT-PCR) assays for the detection of the most common dermatophytes including T. verrucosum in clinical specimens are available. Recently, an ITS2 PCR assay has been successfully used for direct detection of T. verrucosum in paraffin-embedded formalin-fixed skin tissue. The PCR is fast and highly specific. The sensitivity of direct molecular detection of the dermatophytes both in native clinical material, and in paraffin-embedded skin tissue can been increased., (© 2017 Blackwell Verlag GmbH.)

Tinea capitis is a dermatophyte infection common among prepubertal children in sub-Saharan Africa and mainly caused by Trichophyton and Microsporum species. Accurate identification is challenging as conventional methods like culture and microscopy are slow and mostly based on morphological characteristics, which make them less sensitive and specific. Modern molecular methods, like polymerase chain reaction (PCR) assays, are gaining acceptance and are quick as well as accurate. The aim of this study was to investigate the clinical patterns of tinea capitis and to accurately identify the most common causative dermatophytes affecting the scalps of children aged 1 to 16 years attending the Skin Clinic at Mbarara University of Science and Technology (MUST), Mbarara, Uganda, East Africa, using both conventional mycological methods and PCR-ELISA for detection of dermatophyte DNA. One hundred fifteen clinical samples from children from Western Uganda attending the MUST Skin Clinic with a clinical diagnosis of tinea capitis were analyzed. T. violaceum was identified as the most common causative agent, followed by M. audouinii, T. soudanense, and T. rubrum. The early identification of the causative agent of tinea capitis is a prerequisite for the effective management of the disease, the identification of probable source and the prevention of spreading. Children with tinea capitis in Western Uganda should be treated by systemic therapy rather than topical preparations to ensure high cure rates as the most common causative dermatophytes T. violaceum exhibits an endothrix rather than ectothrix invasion of the hair follicle., (© The Author 2016. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

In Germany, infections due to the zoophilic dermatophyte Trichophyton (T.) species of Arthroderma benhamiae are being more frequently diagnosed. The source of infection of this emerging pathogen overlaps with that of the zoophilic species T. interdigitale. The most common source are guinea pigs. T. species of Arthroderma benhamiae causes inflammatory dermatophytosis in children and adolescents. In addition to tinea capitis, it may cause both tinea corporis, tinea manus and frequently tinea faciei. In Germany, T. species of Arthroderma benhamiae is a frequent zoophilic dermatophyte, which in regions is probably more frequent than Microsporum canis. The mycological identification of the isolates with their yellow stained colonies is based on their macroscopic and microscopic features. However, some exhibit colony features consistent with those of T. interdigitale. These strains only can be identified unambiguously by means of molecular techniques. Using detection methods such as PCR-ELISA or real-time PCR, the dermatophyte can be identified directly from clinical material. Sequencing of the internal transcribed spacer region (ITS) of the ribosomal DNA has been approved as culture confirmation test for T. species of Arthroderma benhamiae. In addition, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI TOF MS) is useful. Widespread dermatophytosis due to T. species of Arthroderma benhamiae, in particular of tinea capitis, requires oral antifungal agents. Terbinafine is most effective, alternatives are fluconazole and itraconazole., (© 2014 Deutsche Dermatologische Gesellschaft (DDG). Published by John Wiley & Sons Ltd.)

Identification of dermatophytes is currently performed based on morphological criteria and is increasingly supported by genomic sequence comparison. The present study evaluates an alternative based on the analysis of clinical fungal isolates by mass spectrometry. Samples originating from skin and nail were characterized morphologically and by sequencing the internal transcribed spacer 1 (ITS1), ITS2 and the 5.8S rDNA regions of the rDNA clusters. In a blind comparative study, samples were analyzed by matrix assisted laser desorption/ionization time-of-flight (MALDI-TOF MS). The mass spectra were compared to a database comprising of the spectral data of reference strains by applying the saramis software package. All fungal isolates belonging to the taxa Trichophyton rubrum, T. interdigitale, T. tonsurans, Arthroderma benhamiae and Microsporum canis were correctly identified, irrespective of host origin and pathology. To test the robustness of the approach, four isolates were grown on five different media and analyzed. Although the resulting mass spectra varied in detail, a sufficient number of signals were conserved resulting in data sets exploitable for unequivocal species identification. Taken together, the usually widespread dermatophytes can be identified rapidly and reliably by mass spectrometry. Starting from pure cultures, MALDI-TOF MS analysis uses very simple sample preparation procedures, and a single analysis is performed within minutes. Costs for consumables as well as preparation time are considerably lower than for PCR analysis.

Tinea corporis classically presents as an erythematous annular plaque with a scaly, centrifugally advancing border. However, sometimes vesicles and pustules are observed. Occasionally, even frank bullae appear secondary to severe inflammation. Diagnostic difficulties arise when atypical manifestations mimic other inflammatory skin diseases, including atopic or seborrheic dermatitis, subacute cutaneous lupus erythematosus, or vesicular diseases. We report five cases of atypical tinea corporis, where the initial clinical diagnosis was different from dermatophytosis. The differential diagnoses and the diagnostic difficulties related to atypical manifestations of fungal infections are discussed. Moreover, our cases emphasise the importance of conventional histological examination, which enables a fast, correct diagnosis.

From the epidemiological point of view, Trichophyton rubrum is the most important dermatophyte in the Western world. Mostly, the lesions of fungal infections of the skin are restricted and circumscribed. Immunodeficiency, diabetes or treatment with steroids, however, favour widespread disease involving the entire integument. In the present study, we describe a patient without immunodeficiency or diabetes presenting with widespread tinea corporis caused by T. rubrum. The fungal isolate showed atypical morphological features. Moreover, the typical metabolic features (negative urease test, production of red pigment on potato dextrose agar) were expressed with delay after 6 weeks of cultivation. Thus, sequencing of the internal transcribed spacer of the ribosomal DNA was applied to identify the fungal isolate and led us to the correct diagnosis, before conventional mycological methods were successful.

Summary: Background: The Indian ITS genotype VIII Trichophyton mentagrophytes population shows a high amount of different erg1 (ergosterol) mutants encoding for squalene epoxidase, which catalyses the first step of ergosterol biosynthesis. Objectives: Illumination of the implication of point mutations at position Ala448Thr in single and double erg1 T mentagrophytes mutants because mutants of this type were abundantly found within the Indian fungal population. Methods: Growth in fluconazole or terbinafine containing medium was analysed using a microplate‐laser‐nephelometry (MLN)‐based growth assay. Results: Ala 448 Thr erg1 single mutants were terbinafine sensitive, but about 50% of isolates showed an increased fluconazole resistance, whereas 95% of the double mutants (Phe 397 Leu, Ala 448Thr) demonstrated combined terbinafine and increased fluconazole resistance. Conclusion: The new Indian T mentagrophytes populations show several point mutations in erg1. Point mutations at position 397 were previously described and cause terbinafine resistance. A large part of the double mutants exhibit resistance to terbinafine and fluconazole, demonstrating a selective advantage of the combination of both mutations. [ABSTRACT FROM AUTHOR]