A Polyphasic Approach to Classification and Identification of Species within the Trichophyton benhamiae Complex

Changes in fungal taxonomy: mycological rationale and clinical implications

Numerous fungal species of medical importance have been recently subjected to and will likely continue to undergo nomenclatural changes as a result of the application of molecular approaches to fungal classification together with abandonment of dual nomenclature. Here, we summarize those changes affecting key groups of fungi of medical importance, explaining the mycological (taxonomic) rationale that underpinned the changes and the clinical relevance/importance (where such exists) of the key nomenclatural revisions. Potential mechanisms to mitigate unnecessary taxonomic instability are suggested, together with approaches to raise awareness of important changes to minimize potential clinical confusion.

Hedgehog Dermatophytosis: Understanding Trichophyton erinacei Infection in Pet Hedgehogs and Its Implications for Human Health

Pet hedgehogs, which are increasingly favoured companions, have garnered attention due to their potential as carriers of zoonotic diseases. These small insectivorous mammals, native to Europe, Asia, and Africa, are commonly kept as pets. The encroachment of humans into hedgehog habitats has brought these animals closer to people, raising concerns about disease transmission. This article reviews the current knowledge regarding zoonotic disease associated with pet hedgehogs, with a particular focus on mycotic infections caused by Trichophyton erinacei. Data from various regions and hedgehog species are synthesised to assess the significance of pet hedgehogs as potential reservoirs and transmitters of zoonotic pathogens. Our study highlights the importance of understanding the health risks associated with pet hedgehogs and underscores the need for continued research to mitigate zoonotic disease transmission from these potentially disease-carrying companions.

First record of Trichophyton benhamiae isolated from domestic cats in Russia

We report a first case of Trichophyton benhamiae isolation from domestic cats in Russia. Genetically affiliated to European strains T. benhamiae were deposited in NCBI. T. benhamiae strains formed zonal cream-colored colonies, with reversum pigmentation ranging from intensive yellow to orange-brown in one and orange-brown to chocolate in the second strain. Mycelium is colorless, hyphae are septated, rapidly aging with the formation of arthrospores and microconidia. The formation of macroconidia was recorded after 48 hours. A favorable outcome of treatment was recorded after two weeks.

Polyphasic Systematics of the Fungicolous Genus Cladobotryum Based on Morphological, Molecular and Metabolomics Data

(1) Background: Species of the anamorphic genus Cladobotryum, are known for their fungicolous lifestyle, making them important mycopathogens in fungiculture. Many morphological, ecological, and molecular phylogenetic studies of the genus have been done to date, but taxonomic uncertainties and challenges still remain. Fungal secondary metabolites, being vastly diverse, are utilised as an extra tool in fungal systematics. Despite being studied for their potentially bioactive compounds, Cladobotryum species are insufficiently investigated regarding metabolomics. (2) Methods: The aim of this study is the identification of Greek strains of Cladobotryum by integrating morphological data, ITS-based phylogeny, and ¹H NMR-based metabolomics into a polyphasic approach. (3) Results: Twenty-three strains, isolated from sporophores of macromycetes inhabiting diverse Greek ecosystems, were morphologically identified as Cladobotryum apiculatum, C. fungicola, C. mycophilum, C. varium, C. verticillatum, and Hypomyces rosellus (anamorph C. dendroides), whereas seven strains, which produced red-pigmented metabolites, presented an ambiguous taxonomic position at the species level. Molecular phylogenetics and metabolomics corroborated the morphological findings. (4) Conclusions: Thorough morphological study, ITS region-based phylogeny, and NMR-based metabolomics contribute complementarily to resolving the genus Cladobotryum systematics.

Case Report and Literature Review of Impetigo-Like Tinea Faciei

Impetigo, commonly caused by bacteria, is characterized by lesions of pustules, bullae or golden yellow crusts; it is seldom caused by fungi. Here, we report one case of a 17-year-old female patient with a 1-month history of erythematous pustules on her left cheek. She was clinically diagnosed with “impetigo”, but did not respond to 1 week of treatment with topical mupirocin cream (antibacterial agent). We then saw that a fungal colony grew on the culture, which was identified as T. mentagrophytes based on the morphological and molecular characteristics. The patient was then diagnosed with tinea faciei and was topically treated with 0.2% ketoconazole cream twice per day for 7 days. Through a literature review, we found another 18 cases of impetigo-like tinea faciei with similar clinical manifestations and pathogenic characteristics. Among these, the most common causative agent was T. mentagrophytes complex, which frequently occurs in children and adolescents and exhibits no gender preferences. Systemic and topical antifungals such as terbinafine or itraconazole are effective for impetigo-like tinea faciei caused by T. mentagrophytes complex. However, prolonged course of impetigo in more than 50% cases highlights the importance of mycological examination when dealing with apparent antibiotic-resistant impetigo cases in clinical settings.

Investigations upon the Improvement of Dermatophyte Identification Using an Online Mass Spectrometry Application

Online MALDI-TOF mass spectrometry applications, such as MSI-2, have been shown to help identify dermatophytes, but recurrent errors are still observed between phylogenetically close species. The objective of this study was to assess different approaches to reduce the occurrence of such errors by adding new reference spectra to the MSI-2 application. Nine libraries were set up, comprising an increasing number of spectra obtained from reference strains that were submitted to various culture durations on two distinct culture media: Sabouraud gentamicin chloramphenicol medium and IDFP Conidia medium. The final library included spectra from 111 strains of 20 species obtained from cultures on both media collected every three days after the appearance of the colony. The performance of each library was then analyzed using a cross-validation approach. The spectra acquisitions were carried out using a Microflex Bruker spectrometer. Diversifying the references and adding spectra from various culture media and culture durations improved identification performance. The percentage of correct identification at the species level rose from 63.4 to 91.7% when combining all approaches. Nevertheless, residual confusion between close species, such as Trichophyton rubrum, Trichophyton violaceum and Trichophyton soudanense, remained. To distinguish between these species, mass spectrometry identification should take into account basic morphological and/or clinico-epidemiological features.