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Vazheva G, Zisova L, Miteva-Katrandzhieva T, Dichev V, Chonov V. Comparative analysis in diagnosis by real-time polymerase chain reaction versus direct microscopy, culture, and histology in fungal infections of the nails, scalp, and skin. Int J Dermatol 2023; 62:1499-1505. [PMID: 37776141 DOI: 10.1111/ijd.16857] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Revised: 08/22/2023] [Accepted: 09/14/2023] [Indexed: 10/01/2023]
Abstract
BACKGROUND The diagnosis of superficial fungal infections is the subject of intensive research in many countries around the world. The diagnostic methods used are diverse, including both conventional and innovative techniques. METHODS This study evaluates the sensitivity, specificity, and efficacy of the real-time polymerase chain reaction (PCR) methodology and compares them with those of the conventional methods - direct microscopic, cultural, and histological examinations of materials from hair, skin, and nails - in order to demonstrate the benefits and significance of real-time PCR for the diagnosis of dermatophytic infections. RESULTS The values obtained for the sensitivity, specificity, and efficacy of direct microscopic, cultural, histological, and real-time PCR studies are as follows: 63.71, 88.89, and 72.96% (P < 0.001); 58.06, 100, and 73.47% (P < 0.001); 85.96, 100, and 90.70% (P < 0.001); 88.52, 100, and 92.63% (P < 0.001). CONCLUSION The use of real-time PCR in the diagnosis of dermatophytic infections is a relatively new approach in mycology and is subject to testing and experience from its use. The results are promising, but the method has not yet established itself as a new gold standard in the diagnosis of superficial fungal infections caused by dermatophytes, though its application would be very useful in identifying isolates without conidiogenesis or absence of growth.
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Affiliation(s)
- Gergana Vazheva
- Department of Dermatology and Venereology, Medical University of Plovdiv, Plovdiv, Bulgaria
| | - Liliya Zisova
- Department of Dermatology and Venereology, Medical University of Plovdiv, Plovdiv, Bulgaria
| | | | - Valentin Dichev
- Department of Medical Biology, Medical University of Plovdiv, Plovdiv, Bulgaria
| | - Veselin Chonov
- Department of General and Clinical Pathology, Medical University of Plovdiv, Plovdiv, Bulgaria
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Vazheva GZ, Zisova LG, Becheva EA, Chonov VR, Dichev VD, Miteva-Katrandzhieva TM, Rachkovska ZV, Orbetzova MM, Belovezhdov VT. In search of dermatophytes - frequency and etiology of fungal infections in patients with and without diabetes mellitus. Folia Med (Plovdiv) 2022; 64:922-931. [PMID: 36876571 DOI: 10.3897/folmed.64.e85486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2022] [Accepted: 07/12/2022] [Indexed: 01/01/2023] Open
Abstract
INTRODUCTION Onychomycosis is a frequent nail disorder, accounting for up to 50% of all nail problems. Treatment of onychomycosis is expensive and requires a long time of antifungal medications. Consequently, a proper and faster diagnosis is necessary. Especially for those patients with diabetes mellitus, where onychomycosis is among the most significant predictors of foot ulcer and possible severe complications.
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Affiliation(s)
| | | | | | | | | | | | | | - Maria M Orbetzova
- Clinic of Endocrinology and Metabolic Diseases, St George University Hospital, Plovdiv, Bulgaria
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Müs Tak HK, Ünal G, Müs Tak INBA. Detection of Microsporum canis and Trichophyton mentagrophytes by loop-mediated isothermal amplification (LAMP) and real-time quantitative PCR (qPCR) methods. Vet Dermatol 2022; 33:516-522. [PMID: 36000592 DOI: 10.1111/vde.13111] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Revised: 06/03/2022] [Accepted: 06/16/2022] [Indexed: 11/29/2022]
Abstract
BACKGROUND Dermatophytes are infectious zoonotic fungal agents that are common in animals worldwide. A new loop-mediated isothermal amplification (LAMP) method and quantitative (q)PCR can be used for identifying these agents. Both methods have high specificity and sensitivity, and are simple and quick to use. HYPOTHESIS/OBJECTIVES To develop a LAMP and a rapid multiplex qPCR method for detecting Microsporum canis and Trichophyton mentagrophytes, which are the most common fungal species isolated from cats and dogs. MATERIAL AND METHODS Both methods targeted the CHS-1 gene. Their specificity and sensitivity were tested using 64 M. canis and 44 T. mentagrophytes field strains. The validation of the methods was performed using 250 clinical fungal-positive hair samples. RESULTS The specificity value was 100% for both methods. For LAMP, the sensitivity value was 96.9% for M. canis and 93.2% for T. mentagrophytes. For qPCR, the sensitivity values were 98.4% for M. canis and 97.7% for T. mentagrophytes. Similar specificity and sensitivity results were obtained from the validation study using 250 clinical hair samples. LAMP and multiplex qPCR took 30 and 45 min (respectively) for both targets. The limit of detection (LOD) assays for both targets were 10 and 1 spore/mL for LAMP and multiplex qPCR, respectively. CONCLUSION These findings demonstrate that the LAMP and multiplex qPCR methods targeting CHS-1 gene developed in this study can be used both for point-of-care testing and in the laboratory for detecting M. canis and T. mentagrophytes with high specificity and sensitivity with an internal control.
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Affiliation(s)
- Hamit Kaan Müs Tak
- Ankara University Faculty of Veterinary Medicine, Department of Microbiology, Ankara, Turkey
| | - Gültekin Ünal
- Ankara University Faculty of Veterinary Medicine, Department of Microbiology, Ankara, Turkey
| | - I Nci Bas Ak Müs Tak
- Ankara University Faculty of Veterinary Medicine, Department of Microbiology, Ankara, Turkey
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Comparison of Fungal Fluorescent Staining and ITS rDNA PCR-based Sequencing with Conventional Methods for Diagnosis of Onychomycosis. JOURNAL OF PURE AND APPLIED MICROBIOLOGY 2022. [DOI: 10.22207/jpam.16.2.62] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Accurate identification of fungal causes for onychomycosis is essential for proper treatment. Presently available laboratory methods show unreliable sensitivity; so there is a requirement for innovative detection techniques. The aim for this work was to assess the efficiencies of fluorescent staining and internal transcribed spacer (ITS) ribosomal DNA (rDNA) polymerase chain reaction (PCR)-based sequencing in comparison to conventional techniques for diagnosis of onychomycosis. Nail specimens obtained from 100 patients with clinically- diagnosed onychomycosis were analyzed. Nail scrapings or clippings were subjected to direct microscopic examination by KOH mount, culture by using Sabouraud’s dextrose agar and histopathological examination with periodic-acid Schiff (PAS). Collected specimens were subsequently examined by fluorescent staining and PCR-based sequencing (30 specimens only) to compare the feasibility, sensitivity and diagnostic accuracy for these two methods. The most frequently isolated fungi were yeasts (39/76: 51.3%), dermatophytes (24/76; 31.6%) and non-dermatophyte molds (NDMs) (13/76; 17.1%). Mixed mycotic infections were recovered from 6% of the collected nail specimens. The positive detection rates were significantly different between KOH examinations (52%), nail plate histology (55%), fungal culture (70%) and fluorescent staining (80%). Considering fungal culture as the gold standard, the most sensitive technique was PCR (100%) followed by fluorescent staining (89%), PAS staining (69%) while the least sensitive technique was KOH mount (53%). Fluorescence staining can be used as a rapid and high-yield technique for identification of fungi in the specimens. PCR-based sequencing was highly sensitive and faster compared to culture. Whenever possible, it enables species identification with higher adequacy.
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Gnat S, Łagowski D, Nowakiewicz A, Trościańczyk A, Dyląg M. New Reference Genes for qRT-PCR Analysis as a Potential Target for Identification of Trichophyton verrucosum in Different Culture Conditions. Pathogens 2021; 10:pathogens10111361. [PMID: 34832515 PMCID: PMC8618703 DOI: 10.3390/pathogens10111361] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Revised: 10/09/2021] [Accepted: 10/18/2021] [Indexed: 11/17/2022] Open
Abstract
Dermatophytes are a group of filamentous fungi infecting skin, hair, and nails that raise great diagnostic difficulties. qRT-PCR is a reliable technique for quantifying gene expression with increasingly frequent use in mycological diagnostics. Knowledge of genes and molecular markers with potential to be used in the identification of dermatophytes is of great importance for the development of this branch of diagnostics. In this article, the suitability of six candidate reference genes (TUBB, ACTB, ADPRF, RPL2, SDHA, and EEF1A1) was investigated for gene expression analysis in the dermatophyte Trichophyton verrucosum, which was cultured in various mycological media that are commonly used in a diagnostic laboratory, i.e., Sabouraud, potato dextrose, and keratin-supplemented MM-Cove. The different culture conditions are extremely important factors for the growth and physiology of dermatophytes. Gene expression stability was evaluated using geNorm, NormFinder, BestKeeper, and RefFinder algorithms. Regarding the stability of expression, SDHA was the most stable housekeeping gene; hence, this gene is recommended for future qRT-PCR studies on T. verrucosum strains. These results allow us to conclude that the SDHA gene can be an additional good candidate as an identification target in the qRT-PCR technique.
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Affiliation(s)
- Sebastian Gnat
- Department of Veterinary Microbiology, Faculty of Veterinary Medicine, University of Life Sciences, Akademicka 12, 20-033 Lublin, Poland; (A.N.); (A.T.)
- Correspondence: (S.G.); (D.Ł.); Tel.: +48-81-445-60-93 (S.G.); +48-81-445-66-96 (D.Ł.)
| | - Dominik Łagowski
- Department of Veterinary Microbiology, Faculty of Veterinary Medicine, University of Life Sciences, Akademicka 12, 20-033 Lublin, Poland; (A.N.); (A.T.)
- Correspondence: (S.G.); (D.Ł.); Tel.: +48-81-445-60-93 (S.G.); +48-81-445-66-96 (D.Ł.)
| | - Aneta Nowakiewicz
- Department of Veterinary Microbiology, Faculty of Veterinary Medicine, University of Life Sciences, Akademicka 12, 20-033 Lublin, Poland; (A.N.); (A.T.)
| | - Aleksandra Trościańczyk
- Department of Veterinary Microbiology, Faculty of Veterinary Medicine, University of Life Sciences, Akademicka 12, 20-033 Lublin, Poland; (A.N.); (A.T.)
| | - Mariusz Dyląg
- Department of Mycology and Genetics, Faculty of Biological Sciences, University of Wroclaw, 51-148 Wroclaw, Poland;
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Gill P, Kaur S, Gupta A. Arbitrarily primed polymerase chain reaction-based identification of dystrophic onychomycosis. ARCHIVES OF MEDICINE AND HEALTH SCIENCES 2020. [DOI: 10.4103/amhs.amhs_31_20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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Piri F, Zarei Mahmoudabadi A, Ronagh A, Ahmadi B, Makimura K, Rezaei-Matehkolaei A. Assessment of a pan-dermatophyte nested-PCR compared with conventional methods for direct detection and identification of dermatophytosis agents in animals. Mycoses 2018; 61:837-844. [PMID: 29944743 DOI: 10.1111/myc.12821] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Revised: 06/22/2018] [Accepted: 06/22/2018] [Indexed: 11/26/2022]
Abstract
Conventional direct microscopy with potassium hydroxide (KOH) and culture were found to lack the ability to establish a fast and specific diagnosis of dermatophytosis. A pan-dermatophyte nested-PCR assay was developed using a novel primer pair targeting the translation elongation factor 1-α (Tef-1α) sequences for direct detection and identification of most veterinary relevant dermatophytes in animal samples suspected to dermatophytosis. A total of 140 animal skin and hair samples were subjected to direct microscopy, culture, and ITS-RFLP/ITS-sequencing of culture isolates for the detection and identification of dermatophytosis agents. Nested-PCR sequencing was performed on all the extracted DNAs using a commercial kit after dissolving the specimens by mechanical beating. Nested-PCR was positive in 90% of samples, followed by direct microscopy (85.7%) and culture (75%). The degree of agreement between nested-PCR and direct microscopy (94.4%) was higher than with culture (83.3%). In 105 culture-positive cases, the measures of agreement for the identification of dermatophytosis agents were as follows: 100% between nested-PCR sequencing and ITS-RFLP/ITS-sequencing and 63.8% between nested-PCR sequencing and culture. The developed nested-PCR was faster as well as more sensitive and specific than conventional methods for detection and identification of dermatophytes in clinical samples, which was particularly suitable for epidemiological studies.
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Affiliation(s)
- Fahimeh Piri
- Infectious and Tropical Diseases Research Center, Health Research Institute, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.,Department of Medical Mycology, School of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Ali Zarei Mahmoudabadi
- Infectious and Tropical Diseases Research Center, Health Research Institute, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.,Department of Medical Mycology, School of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Ali Ronagh
- Department of Clinical Sciences, Faculty of Veterinary Medicine, Shahid Chamran University of Ahvaz, Ahvaz, Iran
| | - Bahram Ahmadi
- Department of Medical Laboratory Sciences, School of Para-Medicine, Bushehr University of Medical Sciences, Bushehr, Iran
| | - Koichi Makimura
- Division of Clinical Laboratory Medicine, Graduate School of Medical Care and Technology, Teikyo University, Tokyo, Japan.,Laboratory of Space and Environmental Medicine, Graduate School of Medicine, Teikyo University, Tokyo, Japan
| | - Ali Rezaei-Matehkolaei
- Infectious and Tropical Diseases Research Center, Health Research Institute, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.,Department of Medical Mycology, School of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
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Distribution of Species of Dermatophyte Among Patients at a Dermatology Centre of Nghean Province, Vietnam, 2015-2016. Mycopathologia 2017; 182:1061-1067. [PMID: 28831770 DOI: 10.1007/s11046-017-0193-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Accepted: 08/10/2017] [Indexed: 10/19/2022]
Abstract
INTRODUCTION Vietnam is a tropical country so fungal diseases including dermatophytosis may be prevalent, but epidemiological profiles of agents responsible for the infection have rarely been reported. OBJECTIVE To find out the distribution of dermatophytes among patients living in a central province of Vietnam. METHODS We examined dermatophyte infections in patients with lesions suspected of dermatophytosis referred to the Nghean provincial leprosy and dermatology centre from August 2015 to August 2016. The speciation of dermatophyte was performed by conventional and molecular approaches. RESULTS One hundred and thirty-six patients (90 males and 46 females) were included. Those aged from 11 to 30 contribute 59.1%. The most common agent found was Trichophyton rubrum (66.9%), followed by T. interdigitale (12.5%), T. tonsurans (9.6%), Microsporum incurvatum (8.1%), and the less frequent species were M. canis (2.2%) and T. violaceum (0.7%). Epidermophyton floccosum was not reported. T. rubrum were more common in men (74.4%) than in women (52.2%), while T. interdigitale and M. incurvatum were more common in women (21.7 and 15.2%) than in men (7.8 and 4.4%). Patients infected with Microsporum spp. had small-sized lesions for only 3 months, while those affected by Trichophyton spp. had large-sized lesions with longer duration. CONCLUSION Trichophyton species are the predominant agents of infection in Nghean province, while Epidermophyton species is absent. Additional investigations are required to clarify the epidemiological profile of dermatophytes in Vietnam.
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