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The fungi Trichophyton mentagrophytes and T interdigitale account for significant amount of dermatophytosis cases worldwide. These two dermatophytes form a species complex and have a number of ribosomal internal transcribed spacer (ITS) region genotypes, allowing simultaneous species identification and strain typing. Our aim was to describe the geographic distribution of T mentagrophytes/T interdigitale ITS region genotypes and find an association between the genotypes and clinical presentations of respective infections. We performed rDNA ITS region sequencing in 397 Iranian T mentagrophytes/T interdigitale isolates and analysed all available in GenBank entries with sequences of this kind. For the study, 515 clinical annotations were available. Statistical analysis was performed by chi-squared test and Spearman rank correlation analysis. A total of 971 sequences belonged to genotypes with at least 10 geographic annotations and were classified on the basis of exclusive occurrence in a particular region or high relative contribution to a regional sample. We discerned Asian and Oceanian ("KU496915" Type V, "KT192500" Type VIII, "KU315316"), European ("FM986750" Type III, "MF926358" Type III*, "KT285210" Type VI) and cosmopolitan ("FM986691" Type I, "JX122216" Type II, "KP132819" Type II* and "AF170453" Type XXIV) genotypes. There was statistically significant difference in the ITS genotype distribution between different affected body sites. Trichophyton mentagrophytes "KT192500" Type VIII correlated with tinea cruris, T mentagrophytes "KU496915" Type V correlated with tinea corporis, T interdigitale "JX122216" Type II correlated with tinea pedis and onychomycosis. Trichophyton mentagrophytes and T interdigitale genotypes can be associated with distinct geographic locations and particular clinical presentations., (© 2019 Blackwell Verlag GmbH.)

In a preschool a long-lasting outbreak of Trichophyton (T.) tonsurans tinea capitis was stopped by a concurrent screening of all persons at-risk (N = 264) with the hairbrush technique and a therapy based on clinical picture as well as on the quantitative results of the culture. In addition to the 5 symptomatic patients 10 asymptomatic carriers undetected until now were especially important as vectors. With the rising incidence of T. tonsurans and T. violaceum and the return of Microsporum (M.) audouinii in central Europe such outbreaks are likely to occur more frequently. According to the literature an early and comprehensive screening of the entire at-risk population, a combined antimycotic therapy of the symptomatic and at least a topical therapy of the asymptomatic as well as measures of decontamination are important conditions for successful outbreak management. In our hands the hairbrush technique is a reliable, painless and easy-to-perform screening method which also allows a quantification of fungal load.

Trichophyton schoenleinii is an anthropophilic dermatophyte usually causing tinea favosa. Only few studies have provided data on molecular epidemiology and antifungal profiles of this fungus due to its limited prevalence after 1950s. Forty-nine strains from Asia (n = 27), Africa (n = 10), Europe (n = 10) and from unknown regions (n = 2) were analysed with amplified fragment length polymorphism fingerprinting (AFLP) to reveal intraspecific genetic diversity in this dataset. Amplified fragment length polymorphism fingerprinting genotyping revealed five clusters which did not correspond to geographic origins or clinical characteristics. Additionally, in vitro antifungal susceptibility to seven antifungals was provided for all strains. Terbinafine, ketoconazole, miconazole and itraconazole proved to be the most effective drugs, followed by griseofulvin. No correlation between genotypes and differences in antifungal susceptibility was observed. It is concluded that the AFLP groups are lineages within a single species., (© 2018 Blackwell Verlag GmbH.)

Trichophyton bullosum is a zoophilic dermatophyte from the Arthroderma benhamiae complex with a poorly known distribution. In this study, we report a case of dermatophytosis caused by T. bullosum in a 6-year-old male horse who had a skin lesion located in a saddle area. The infection spread rapidly to the upper chest and to both sides of the trunk. The dermatophyte was isolated in culture and identified by sequence analysis of the internal transcribed spacer regions (ITS rDNA). To date, this is the first verified case of animal infection due to T. bullosum in Europe following the 2012 report of human infection in France. We hypothesize that this species can be relatively common in horses and donkeys, but it is confused with other zoophilic species responsible for infections with similar clinical manifestations, and when isolated in culture, it is misidentified as the phenotypically similar T. verrucosum. Previous cases of dermatophytosis caused by T. verrucosum-like dermatophytes in horses and donkeys were reviewed together with human infections transmitted from these animals. This summary estimates possible distribution width of T. bullosum. The taxonomy of T. verrucosum-like dermatophytes is extremely difficult due to lack of original material and poor morphology of species. Molecular genetic methods are necessary to verify the identification of these fungi. ITS1 or ITS2 region of rDNA alone is sufficient for correct identification.

Trichophyton raubitschekii is a rare dermatophyte which belongs to the Trichophyton rubrum species complex. Since 1981, only a few cases of dermatophytosis due to this anthropophilic causative agent were published. In this paper the authors report the first cases of Tinea corporis caused by Trichophyton raubitschekii (syn. T. rubrum) in Europe. The patients, one immigrant from Ghana and three from Cameroon, had typical lesions of tinea corporis. Four strains were isolated and characterized by conventional and molecular methods. On morphological and physiological grounds the isolates were identified as T. raubitschekii by the following phenotypical features: (1) velvety colony texture; (2) brown pigment; (3) abundant macroconidia and (4) positive urease activity. Molecular diagnostics were performed by single strand conformation polymorphism (SSCP) and sequence analysis of the ATPase9 intron of the mitochondrial (mt) DNA and the internal transcribed spacer (ITS) region of the rDNA, respectively. The ITS sequences and SSCP patterns of the ATPase9 intron were found to be identical among the four strains and also when compared to reference strains of T. rubrum. As shown in the present paper, T. raubitschekii is genetically identical to T. rubrum but differs in some phenotypical characteristics. Since misidentification with other dark-coloured dermatophyte variants is possible, medical mycologists should bear in mind the special morphological characteristics of T. raubitschekii (syn. T. rubrum) for future identifications.

Trichophyton mentagrophytes is a common cosmopolitan dermatophyte species composed of two varieties: T. mentagrophytes var. interdigitale (anthropophilic form) and T. mentagrophytes var. mentagrophytes (zoophilic form). We used a random amplified polymorphic DNA (RAPD) method to study the genetic diversity of 46 clinical isolates of the T. mentagrophytes complex collected from 38 patients with different geographical origins (Europe, Africa, South America). The T. mentagrophytes were isolated either from a unique lesion for 31 patients, including two patients living together, or from at least two sites for seven patients. Only one primer of 15 primers tested showed DNA polymorphism in the isolates, producing 23 distinct patterns belonging to three clusters. There was no specific cluster grouping isolates from the same geographical origin. The same pattern is shared by all the four T. mentagrophytes var. mentagrophytes and 13 of 42 T. mentagrophytes var. interdigitale. An identity of strains responsible for several lesions in seven individuals suggests an homogeneous T. mentagrophytes population in the case of multiple lesions. In contrast, the dissimilarity of two strains recovered from two patients living together argues against person-to-person transmission in that case. This study indicates that RAPD can be successfully applied to show genetic diversity among T. mentagrophytes isolates.