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Mehlhorn C, Uhrlaß S, Klonowski E, Krüger C, Paasch U, Simon JC, Nenoff P. [Conventional and molecular diagnostics in onychomycosis-part 2 : Molecular identification of causative dermatophytes by polymerase chain reaction and sequence analysis of the internal transcribed spacer region of ribosomal DNA]. DERMATOLOGIE (HEIDELBERG, GERMANY) 2024; 75:238-252. [PMID: 38095686 DOI: 10.1007/s00105-023-05265-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 11/02/2023] [Indexed: 02/24/2024]
Abstract
Dermatophyte identification using traditional methods such as optics-based direct fluorescence microscopy and culture is nowadays supplemented by molecular biological methods. The validity of dermatophyte DNA detection with direct uniplex-polymerase chain reaction-enzyme immunoassay (PCR-EIA) in nail samples was proven by sequence analysis of the ribosomal internal transcribed spacer (ITS) region. A total of 108 dermatophytes, isolated from patients with onychomycosis, were positive for Trichophyton rubrum (TR) and Trichophyton interdigitale (TI) in culture and/or uniplex-PCR-EIA. Conventional methods for dermatophyte identification were complemented by direct uniplex-PCR-EIA and sequence analysis of the ribosomal ITS region (18S rRNA, ITS1, 5.8S rRNA, ITS2, 28S rRNA). Of 108 patients (average age 62, median age 73), 56 showed cultural growth with 31 of them being identified as TR and 23 as TI. There was high agreement with the sequence analysis. Surprisingly, the pathogen of a single nail sample was identified as T. quinckeanum (formerly T. mentagrophytes sensu stricto), a rare zoophilic dermatophyte in Germany. A single TI strain turned out to be a misidentified T. tonsurans based on the sequence analysis. In all, 34 of the 52 specimens lacking cultural growth were detected by PCR as TR, and 18 specimens could be identified as TI. The results of dermatophyte identification of culture-negative nail samples were also in agreement with the results of sequence analysis. Molecular biological methods are well applicable, and they show high reliability for direct dermatophyte identification in nail samples without prior cultivation. Especially for nail samples without cultural growth, PCR-based dermatophyte identification was highly specific and sensitive.
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Affiliation(s)
- Carolin Mehlhorn
- Haut- und Laborarzt/Allergologie, Andrologie, Tätigkeitsschwerpunkt: Tropen- und Reisedermatologie (DDA), labopart - Medizinische Laboratorien, Labor Leipzig-Mölbis, Mölbiser Hauptstr. 8, 04571, Rötha/OT Mölbis, Deutschland
| | - Silke Uhrlaß
- Haut- und Laborarzt/Allergologie, Andrologie, Tätigkeitsschwerpunkt: Tropen- und Reisedermatologie (DDA), labopart - Medizinische Laboratorien, Labor Leipzig-Mölbis, Mölbiser Hauptstr. 8, 04571, Rötha/OT Mölbis, Deutschland
| | - Esther Klonowski
- Haut- und Laborarzt/Allergologie, Andrologie, Tätigkeitsschwerpunkt: Tropen- und Reisedermatologie (DDA), labopart - Medizinische Laboratorien, Labor Leipzig-Mölbis, Mölbiser Hauptstr. 8, 04571, Rötha/OT Mölbis, Deutschland
| | - Constanze Krüger
- Haut- und Laborarzt/Allergologie, Andrologie, Tätigkeitsschwerpunkt: Tropen- und Reisedermatologie (DDA), labopart - Medizinische Laboratorien, Labor Leipzig-Mölbis, Mölbiser Hauptstr. 8, 04571, Rötha/OT Mölbis, Deutschland
| | - Uwe Paasch
- Klinik und Poliklinik für Dermatologie, Venerologie und Allergologie, Universitätsklinikum Leipzig AöR und Medizinische Fakultät der Universität Leipzig, Leipzig, Deutschland
| | - Jan C Simon
- Klinik und Poliklinik für Dermatologie, Venerologie und Allergologie, Universitätsklinikum Leipzig AöR und Medizinische Fakultät der Universität Leipzig, Leipzig, Deutschland
| | - Pietro Nenoff
- Haut- und Laborarzt/Allergologie, Andrologie, Tätigkeitsschwerpunkt: Tropen- und Reisedermatologie (DDA), labopart - Medizinische Laboratorien, Labor Leipzig-Mölbis, Mölbiser Hauptstr. 8, 04571, Rötha/OT Mölbis, Deutschland.
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Verrier J, Jeanneau-Imparato L, Guillet C, Bourdeau P, Bouchara JP. PCR-terminal restriction fragment length polymorphism for direct detection and identification of dermatophytes in veterinary mycology. Med Mycol 2019; 57:447-456. [PMID: 30085212 DOI: 10.1093/mmy/myy058] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 07/10/2018] [Indexed: 11/14/2022] Open
Abstract
The biological diagnosis of dermatophytosis in veterinary medicine usually relies on direct microscopic examination and inoculation of the samples on appropriate culture media. However, identification of dermatophytes needs expertise, and cultures which require from days to weeks to be conclusive, may lack of sensitivity because of the quite common overgrowth of contaminants. Here we developed a polymerase chain reaction (PCR) assay based on terminal restriction fragment length polymorphism (TRFLP), which may improve sensitivity of the biological diagnosis and reduce the delay for initiation of treatment. This study was first conducted on pure cultures of various dermatophytes (27 species), yeasts (14 species) and moulds (45 species). After DNA extraction, the internal transcribed spacer (ITS)-28S region of ribosomal DNA was amplified with primers targeting specifically pathogenic dermatophytes, and species of interest were identified by TRFLP with appropriate restriction enzymes. After validation, this assay was applied to veterinary samples and results were compared to those obtained by direct microscopic examination and cultures. All target species were correctly identified, and none of the yeast or mould species was amplified, demonstrating specificity of the assay. Regarding clinical samples, the causative agent was detected by PCR-TRFLP from 97.1% of the samples with both positive direct microscopic examination and cultures. No dermatophytes were detected when both conventional tests were negative. PCR-TRFLP developed here demonstrated to be highly sensitive and specific, allowing rapid detection and direct identification of dermatophytes in veterinary practice. Therefore, this assay is especially suitable for the biological diagnosis of dermatophytosis in different animal species.
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Affiliation(s)
- J Verrier
- Groupe d'Etude des Interactions Hôte-Pathogène (GEIHP, EA 3142), SFR ICAT 4208, UNIV Angers, UNIV Brest, Angers, France
| | - L Jeanneau-Imparato
- Groupe d'Etude des Interactions Hôte-Pathogène (GEIHP, EA 3142), SFR ICAT 4208, UNIV Angers, UNIV Brest, Angers, France.,Laboratoire de Dermatologie-Parasitologie-Mycologie, Oniris - Ecole Nationale Vétérinaire, Agroalimentaire et de l'Alimentation Nantes Atlantique, Nantes, France.,Unité de Nutrition, PhysioPathologie et Pharmacologie (NP3), Oniris - Ecole Nationale Vétérinaire, Agroalimentaire et de l'Alimentation Nantes Atlantique, Nantes, France
| | - C Guillet
- Plateforme d'Analyse Cellulaire et Moléculaire (PACeM, SFR ICAT 4208), UNIV Angers, Université Bretagne-Loire, Angers, France
| | - P Bourdeau
- Laboratoire de Dermatologie-Parasitologie-Mycologie, Oniris - Ecole Nationale Vétérinaire, Agroalimentaire et de l'Alimentation Nantes Atlantique, Nantes, France.,Unité de Nutrition, PhysioPathologie et Pharmacologie (NP3), Oniris - Ecole Nationale Vétérinaire, Agroalimentaire et de l'Alimentation Nantes Atlantique, Nantes, France
| | - J P Bouchara
- Groupe d'Etude des Interactions Hôte-Pathogène (GEIHP, EA 3142), SFR ICAT 4208, UNIV Angers, UNIV Brest, Angers, France.,Laboratoire de Parasitologie-Mycologie, Centre Hospitalier Universitaire, Angers, France
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Molecular characterization of dermatophytes isolated from cattle in Plateau State, Nigeria. Vet Microbiol 2018; 219:212-218. [DOI: 10.1016/j.vetmic.2018.04.022] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Revised: 09/08/2017] [Accepted: 04/12/2018] [Indexed: 11/22/2022]
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Didehdar M, Shokohi T, Khansarinejad B, Ali Asghar Sefidgar S, Abastabar M, Haghani I, Amirrajab N, Mondanizadeh M. Characterization of clinically important dermatophytes in North of Iran using PCR-RFLP on ITS region. J Mycol Med 2016; 26:345-350. [DOI: 10.1016/j.mycmed.2016.06.006] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2016] [Revised: 06/07/2016] [Accepted: 06/22/2016] [Indexed: 11/28/2022]
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