T Ohst1, C Kupsch1, Y Gräser1. 1. National Reference Laboratory for Dermatophytes, Institute for Microbiology and Hygiene, Charité - Universitätsmedizin Berlin, Rahel-Hirsch-Weg 3, 10117, Berlin, Germany.
Abstract
BACKGROUND: Dermatophytes are common fungal pathogens causing mostly superficial infections in humans with a high prevalence worldwide. Traditional detection techniques are time-consuming and insensitive, whereas molecular detection methods have proved to be much more rapid and sensitive. OBJECTIVES: To develop a modular singleplex quantitative real-time polymerase chain reaction (qRT-PCR) assay for the detection of the most common dermatophytes in clinical specimens. METHODS: The qRT-PCR assay is based on single-tube reactions with TaqMan probes. We validated the test with 311 clinical samples of human and animal origin submitted for routine diagnosis and compared the qRT-PCR results with microscopy and culture. RESULTS: qRT-PCR proved to be significantly more sensitive than microscopy and culture, with 21·2% more positive samples. Among the 201 dermatophytes identified 152 were Trichophyton rubrum (75·6%) and 34 were Trichophyton interdigitale (16·9%). Only 15 samples were determined as less common dermatophytes (Microsporum canis, Epidermophyton floccosum, Trichophyton verrucosum and Arthroderma benhamiae). In the present study, pathogen identification was achieved for 95·2% of all samples (including negatives) by applying only three detection tests (pan-dermatophyte, T. rubrum and T. interdigitale). CONCLUSIONS: The qRT-PCR assay developed in this study allows the specific and sensitive detection of relevant dermatophytes at low cost in a short time.
BACKGROUND: Dermatophytes are common fungal pathogens causing mostly superficial infections in humans with a high prevalence worldwide. Traditional detection techniques are time-consuming and insensitive, whereas molecular detection methods have proved to be much more rapid and sensitive. OBJECTIVES: To develop a modular singleplex quantitative real-time polymerase chain reaction (qRT-PCR) assay for the detection of the most common dermatophytes in clinical specimens. METHODS: The qRT-PCR assay is based on single-tube reactions with TaqMan probes. We validated the test with 311 clinical samples of human and animal origin submitted for routine diagnosis and compared the qRT-PCR results with microscopy and culture. RESULTS: qRT-PCR proved to be significantly more sensitive than microscopy and culture, with 21·2% more positive samples. Among the 201 dermatophytes identified 152 were Trichophyton rubrum (75·6%) and 34 were Trichophyton interdigitale (16·9%). Only 15 samples were determined as less common dermatophytes (Microsporum canis, Epidermophyton floccosum, Trichophyton verrucosum and Arthroderma benhamiae). In the present study, pathogen identification was achieved for 95·2% of all samples (including negatives) by applying only three detection tests (pan-dermatophyte, T. rubrum and T. interdigitale). CONCLUSIONS: The qRT-PCR assay developed in this study allows the specific and sensitive detection of relevant dermatophytes at low cost in a short time.
Authors: Jaroslav Lux; Radim Dobiáš; Ivana Kuklová; Radek Litvik; Vladimír Scholtz; Hana Soušková; Josef Khun; Jakub Mrázek; Michaela Kantorová; Pavla Jaworská; Táňa Prejdová; Jana Šnupárková; Petr Hamal; Jaroslav Julák Journal: J Fungi (Basel) Date: 2020-10-10