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Bernard Mignon - One of the best experts on this subject based on the ideXlab platform.

  • th1 and th17 immune responses act complementarily to optimally control superficial Dermatophytosis
    Journal of Investigative Dermatology, 2019
    Co-Authors: Mariepierre Heinen, Ludivine Cambier, Nadine Antoine, Annick Gabriel, Laurent Gillet, Fabrice Bureau, Bernard Mignon
    Abstract:

    Dermatophytoses are among the most common fungal infections worldwide, but little is known about the immune response in them. By comparing Trichophyton benhamiae acute superficial Dermatophytosis in wild-type and Rag2−/− mice, we showed that TCR-mediated immunity is critical for fungal clearance and clinical recovery. In WT mice, CD4+ T cells isolated from the skin-draining lymph nodes exhibit both T helper type (Th) 1 and Th17 differentiation during infection, with regard to produced cytokines or mRNA levels of transcription factors. Using IL-17A– and IFN-γ–deficient mice, we showed that IL-17A and IFN-γ are individually dispensable but together contribute to the optimal resolution of Dermatophytosis. Furthermore, we generated and infected IL-17A and IFN-γ double-deficient mice and showed that both fungal clearance and clinical recovery were much lower in these mice than in single-deficient mice, suggesting the complementary roles of the two cytokines in Dermatophytosis resolution. Thus, our data suggest that TCR-mediated immunity is critical for the optimal control of superficial Dermatophytosis and that adaptive immunity is polarized to both Th1 and Th17 responses, with the Th17 antifungal response acting on dermatophyte clearance and the Th1 response being involved in both fungal clearance and Th17-inflammation down-modulation.

  • assessment of the cutaneous immune response during arthroderma benhamiae and a vanbreuseghemii infection using an experimental mouse model
    British Journal of Dermatology, 2014
    Co-Authors: Ludivine Cambier, Valerie Defaweux, Alodie Weatherspoon, E T Bagut, Mariepierre Heinen, Nadine Antoine, Bernard Mignon
    Abstract:

    Summary Background Dermatophytoses are common but poorly understood skin infections. Most in vivo studies have been performed using the guinea pig as the experimental animal model, which has several limitations. Objectives To develop a mouse model of Dermatophytosis suitable for multiple purposes, including the investigation of immunity against dermatophytes. Materials and methods Two peculiar fungal species, Arthroderma benhamiae and A. vanbreuseghemii, isolated from tinea in humans having contact with rodents were used for epicutaneous inoculation. During the infection, clinical and histopathological follow-up were performed. The recruitment of immune cells was evaluated by immunofluorescence staining and the levels of cytokine mRNA were quantified by quantitative reverse transcriptase-polymerase chain reaction in the skin of infected mice. Results The skin symptoms and microscopic lesions, including the colonization of keratinized epidermal and follicular structures by both dermatophytes, were highly similar to those observed in guinea pig infection models and in natural infections, mimicking acute superficial tinea in humans. The dermal inflammatory cellular infiltrate consisted of macrophages, dendritic cells and especially polymorphonuclear neutrophils, which are one of the histological ‘clues’ to the diagnosis of Dermatophytosis. The in situ cytokine profile was characterized by the overexpression of transforming growth factor-β, interleukin (IL)-1β and IL-6 mRNA during infection, suggesting a role of the T-helper 17 pathway in the establishment of immunity. Conclusions Our new reproducible and validated mouse model of Dermatophytosis is a modern in vivo tool that allows a more in-depth understanding of the pathogenesis of human dermatophyte infections.

  • pets as the main source of two zoonotic species of the trichophyton mentagrophytes complex in switzerland arthroderma vanbreuseghemii and arthroderma benhamiae
    Veterinary Dermatology, 2009
    Co-Authors: Stephane Drouot, Marina Fratti, Petra Roosje, Bernard Mignon, Michel Monod
    Abstract:

    In cases of highly inflammatory Dermatophytosis in humans, it is important to identify the possible source of animal transmission in order to prevent recurrence, family outbreaks or rapidly progressing epidemics. A survey of dermatophytes in pets during a 14-month period in Switzerland revealed, in addition to Microsporum canis, two different species of the Trichophyton mentagrophytes complex, Arthroderma benhamiae and Arthroderma vanbreuseghemii, all causing inflammatory dermatophytoses. Arthroderma benhamiae was only and frequently isolated from guinea pigs. Arthroderma vanbreuseghemii was isolated mainly from European short hair cats, but also from dogs and in one case from a pure-bred cat. Ninety-three percent of the cats carrying A. vanbreuseghemii were hunters and all had skin lesions. In contrast, cats with skin lesions that were strictly indoors were found to be almost exclusively infected by M. canis. Therefore, it can be suspected that infection with A. vanbreuseghemii occurred during hunting and that the natural source of this dermatophyte is either soil or an animal other than the cat, most probably a rodent.

Yvonne Gräser - One of the best experts on this subject based on the ideXlab platform.

  • the agony of choice in dermatophyte diagnostics performance of different molecular tests and culture in the detection of trichophyton rubrum and trichophyton interdigitale
    Clinical Microbiology and Infection, 2016
    Co-Authors: Christiane Kupsch, Torsten Ohst, F Pankewitz, P Nenoff, S Uhrlas, I Winter, Yvonne Gräser
    Abstract:

    Dermatophytosis caused by dermatophytes of the genera Trichophyton and Microsporum belong to the most frequent mycoses worldwide. Molecular detection methods proved to be highly sensitive and enable rapid and accurate detection of dermatophyte species from clinical specimens. For the first time, we compare the performance of different molecular methods with each other and with conventional diagnostics in the detection of dermatophytoses caused by Trichophyton rubrum and Trichophyton interdigitale in clinical specimens (nail, skin and hair). The compared molecular methods comprise two already published PCR-ELISAs, a published quantitative RT-PCR as well as a newly developed PCR-ELISA targeting the internal transcribed spacer region. We investigated the sensitivity of the assays by analysing 375 clinical samples. In 148 specimens (39.5%) a positive result was gained in at least one of the four molecular tests or by culture, but the number of detected agents differed significantly between some of the assays. The most sensitive assay, a PCR-ELISA targeting a microsatellite region, detected 81 T. rubrum infections followed by an internal transcribed spacer PCR-ELISA (60), quantitative RT-PCR (52) and a topoisomerase II PCR-ELISA (51), whereas cultivation resulted in T. rubrum identification in 37 samples. The pros and cons of all four tests in routine diagnostics are discussed.

  • Epidemiological Aspects of Dermatophytosis in Khuzestan, southwestern Iran, an Update
    Mycopathologia, 2016
    Co-Authors: Ali Rezaei-matehkolaei, Koichi Makimura, Yvonne Gräser, Abdollah Rafiei, Maral Gharghani, Batool Sadeghi-nejad
    Abstract:

    Dermatophytosis is among the most common superficial mycoses in Iran. The purpose of this report was to update the clinical and mycological features of human Dermatophytosis in the Khuzestan, southwestern Iran. In the framework of a one-year survey, a total of 4120 skin, hair and nail samples obtained from the outpatients with symptoms suggestive of tinea were analyzed by using direct microscopy, culture and molecular identification methods. Strains isolated from cultures were subjected to amplification of the nuclear rDNA ITS regions in a PCR assay followed by an early established RFLP analysis. For confirmation of species identification, 100 isolates as representatives of all presumable species were subjected to ITS sequencing. Infection was confirmed in 1123 individuals (27.25 %) in the age range of 1–89 years by direct microscopy and/or culture including 603 males versus 520 females. Frequencies of infections were the highest and the lowest in age groups of 21–30 and 11–20 years, respectively. Tinea corporis was the most prevalent clinical manifestation followed by tinea cruris, tinea capitis, tinea manuum, tinea pedis, tinea unguium, tinea faciei and tinea barbae. Trichophyton interdigitale (58.7 %) was the most dominant isolate followed by Epidermophyton floccosum (35.4 %), Microsporum canis (3 %), T. rubrum (1.5 %), T. species of Arthroderma benhamiae (0.5 %), T. tonsurans (0.3 %) and T. violaceum (0.3 %). Other species included M. gypseum , M. fulvum and T. verrucosum (each one 0.1 %). Such a high occurrence of infection with T. interdigitale , which has not been reported from Iran, is due to the use of accurate molecular methods based on new species concept in dermatophytes. The prevalence of dermatophytoses caused by zoophilic species remarkably increased and Trichophyton species of A. benhamiae has emerged as a new agent of Dermatophytosis in southwestern Iran, while infections due to anthropophilic species, except E. floccosum, took a decreasing trend.

  • diagnosis of common dermatophyte infections by a novel multiplex real time polymerase chain reaction detection identification scheme
    British Journal of Dermatology, 2007
    Co-Authors: Michael Arabatzis, Yvonne Gräser, L Bruijnesteijn E S Van Coppenraet, E J Kuijper, G S De Hoog, A P M Lavrijsen, Kate Templeton, E M H Van Der Raaijhelmer, Aristea Velegraki, Richard C Summerbell
    Abstract:

    Summary Background  In the absence of a functional dermatophyte-specific polymerase chain reaction (PCR), current diagnosis of dermatophytoses, which constitute the commonest communicable diseases worldwide, relies on microscopy and culture. This combination of techniques is time-consuming and notoriously low in sensitivity. Objectives  Recent dermatophyte gene sequence records were used to design a real-time PCR assay for detection and identification of dermatophytes in clinical specimens in less than 24 h. Patients and methods  Two assays based on amplification of ribosomal internal transcribed spacer regions and on the use of probes specific to relevant species and species-complexes were designed, optimised and clinically evaluated. One assay was for detecting the Trichophyton mentagrophytes species complex plus T. tonsurans and T. violaceum. The second assayed for the T. rubrum species complex, Microsporum canis and M. audouinii. Results  The analytical sensitivity of both assays was 0·1 pg DNA per reaction, corresponding to 2·5–3·3 genomes per sample. The protocol was clinically evaluated over 6 months by testing 92 skin, nail and hair specimens from 67 patients with suspected Dermatophytosis. Real-time PCR detected and correctly identified the causal agent in specimens from which T. rubrum, T. interdigitale, M. audouinii or T. violaceum grew in culture, and also identified a dermatophyte species in an additional seven specimens that were negative in microscopy and culture. Conclusions  This highly sensitive assay also proved to have high positive and negative predictive values (95·7% and 100%), facilitating the accurate, rapid diagnosis conducive to targeted rather than empirical therapy for dermatophytoses.

Barbara Majer Dziedzic - One of the best experts on this subject based on the ideXlab platform.

  • Molecular identification and classification of Trichophyton mentagrophytes complex strains isolated from humans and selected animal species.
    Mycoses, 2015
    Co-Authors: Grażyna Ziółkowska, Aneta Nowakiewicz, Sebastian Gnat, Aleksandra Trościańczyk, Przemysław Zięba, Barbara Majer Dziedzic
    Abstract:

    Summary Species differentiation within Trichophyton mentagrophytes complex group currently poses a major diagnostic challenge, with molecular methods increasingly supplementing classical identification based on the morphological and physiological properties of the fungi. Diagnostic and epidemiological research aimed at determining the source and means of transmission of dermatophytoses in both humans and animals requires not only species differentiation of isolates but also differentiation within species. The study was conducted on 24 isolates originating in humans and various animal species with clinical symptoms of Dermatophytosis. The analysis included phenotypical identification methods and molecular methods: internal transcribed spacer sequencing and ITS-restriction fragment length polymorphism (RFLP) with multi-enzyme restriction. ITS sequence analysis identified the isolates to species – Trichophyton interdigitale, Arthroderma benhamiae and A. vanbreuseghemii, and ITS-RFLP detected six different genotypes. Genotypes I, II and III characterised strains belonging to A. benhamiae, genotype IV characterised the A. vanbreuseghemii strain, and genotypes V and VI occurred only within the species T. interdigitale. Strains isolated from guinea pigs were dominant within genotype I, while genotype II was found mainly in strains from foxes. Multi-enzyme restriction analysis of this region enables intraspecific differentiation, which may be useful in epidemiological research, particularly in determining the source of infections.

Mehmet Haberal - One of the best experts on this subject based on the ideXlab platform.

Grażyna Ziółkowska - One of the best experts on this subject based on the ideXlab platform.

  • Molecular identification and classification of Trichophyton mentagrophytes complex strains isolated from humans and selected animal species.
    Mycoses, 2015
    Co-Authors: Grażyna Ziółkowska, Aneta Nowakiewicz, Sebastian Gnat, Aleksandra Trościańczyk, Przemysław Zięba, Barbara Majer Dziedzic
    Abstract:

    Summary Species differentiation within Trichophyton mentagrophytes complex group currently poses a major diagnostic challenge, with molecular methods increasingly supplementing classical identification based on the morphological and physiological properties of the fungi. Diagnostic and epidemiological research aimed at determining the source and means of transmission of dermatophytoses in both humans and animals requires not only species differentiation of isolates but also differentiation within species. The study was conducted on 24 isolates originating in humans and various animal species with clinical symptoms of Dermatophytosis. The analysis included phenotypical identification methods and molecular methods: internal transcribed spacer sequencing and ITS-restriction fragment length polymorphism (RFLP) with multi-enzyme restriction. ITS sequence analysis identified the isolates to species – Trichophyton interdigitale, Arthroderma benhamiae and A. vanbreuseghemii, and ITS-RFLP detected six different genotypes. Genotypes I, II and III characterised strains belonging to A. benhamiae, genotype IV characterised the A. vanbreuseghemii strain, and genotypes V and VI occurred only within the species T. interdigitale. Strains isolated from guinea pigs were dominant within genotype I, while genotype II was found mainly in strains from foxes. Multi-enzyme restriction analysis of this region enables intraspecific differentiation, which may be useful in epidemiological research, particularly in determining the source of infections.