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Aho-Laukkanen E, Mäki-Koivisto V, Torvikoski J, Sinikumpu SP, Huilaja L, Junttila IS. PCR enables rapid detection of dermatophytes in practice. Microbiol Spectr 2024:e0104924. [PMID: 39287452 DOI: 10.1128/spectrum.01049-24] [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: 04/26/2024] [Accepted: 08/15/2024] [Indexed: 09/19/2024] Open
Abstract
Dermatophytes cause superficial infections of skin, hair, and nails. Even though they rarely cause severe infections, they are relatively common, particularly in primary health care. Diagnosis of dermatophyte infections has relied on relatively slow culture-based methods. Nucleic acid-based detection (PCR) methods might provide results more rapidly. Here, we describe the transition from culture-based methods into PCR-based methods in Northern Finland with a catchment area of approximately 720,000 mostly Caucasian people. This study included 14,330 samples collected between 2019 and 2022. Our results showed that the PCR-based method has become the diagnostic test of choice for these infections in this area. Commercial real-time PCR assay DermaGenius 2.0 complete multiplex test detected more positive results than culture and covered the most important dermatophytes, Candida albicans, and few less common species. With PCR, the mean turn-around-time from sample request to results decreased from 19 days to 16 hours.IMPORTANCESuperficial fungal infections, dermatophytosis, are remarkably common worldwide, affecting an estimated 20%-25% of the global population. In the diagnosis of these infections, fast and accurate results by PCR shorten the time to diagnosis and help clinicians to avoid unnecessary antifungal treatments.
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Affiliation(s)
| | | | - J Torvikoski
- Department of Clinical Microbiology, HUS Diagnostic Center, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - S P Sinikumpu
- Department of Dermatology and Medical Research Center Oulu, PEDEGO Research Unit, University of Oulu, Oulu University Hospital, Oulu, Finland
| | - L Huilaja
- Department of Dermatology and Medical Research Center Oulu, PEDEGO Research Unit, University of Oulu, Oulu University Hospital, Oulu, Finland
| | - I S Junttila
- Northern Finland Laboratory Center, Nordlab, Oulu, Finland
- Research Unit of Biomedicine and Internal Medicine, University of Oulu, Oulu, Finland
- Cytokine Biology Research Group, Tampere University, Tampere, Finland
- Fimlab Laboratories, Tampere, Finland
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2
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Crawford LC, Kidd SE. Photo Quiz: Subungual organism in a renal transplant patient. J Clin Microbiol 2024; 62:e0171023. [PMID: 39140756 PMCID: PMC11323499 DOI: 10.1128/jcm.01710-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/15/2024] Open
Affiliation(s)
- Lucy C. Crawford
- National Mycology Reference Centre, Microbiology and Infectious Diseases, SA Pathology, Adelaide, South Australia, Australia
| | - Sarah E. Kidd
- National Mycology Reference Centre, Microbiology and Infectious Diseases, SA Pathology, Adelaide, South Australia, Australia
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3
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Deng R, Chen X, Zheng D, Xiao Y, Dong B, Cao C, Ma L, Tong Z, Zhu M, Liu Z, Lu S, Fu M, Jin Y, Yin B, Li F, Li X, Abliz P, Liu H, Zhang Y, Yu N, Wu W, Xiong X, Zeng J, Huang H, Jiang Y, Chen G, Pan W, Sang H, Wang Y, Guo Y, Shi D, Yang J, Ran Y, Hu J, Yang L, Bai S, Yu J, Wang X, Li R. Epidemiologic features and therapeutic strategies of kerion: A nationwide multicentre study. Mycoses 2024; 67:e13751. [PMID: 38825584 DOI: 10.1111/myc.13751] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2024] [Revised: 04/13/2024] [Accepted: 05/26/2024] [Indexed: 06/04/2024]
Abstract
BACKGROUND Kerion is a severe type of tinea capitis that is difficult to treat and remains a public health problem. OBJECTIVES To evaluate the epidemiologic features and efficacy of different treatment schemes from real-world experience. METHODS From 2019 to 2021, 316 patients diagnosed with kerion at 32 tertiary Chinese hospitals were enrolled. We analysed the data of each patient, including clinical characteristics, causative pathogens, treatments and outcomes. RESULTS Preschool children were predominantly affected and were more likely to have zoophilic infection. The most common pathogen in China was Microsporum canis. Atopic dermatitis (AD), animal contact, endothrix infection and geophilic pathogens were linked with kerion occurrence. In terms of treatment, itraconazole was the most applied antifungal agent and reduced the time to mycological cure. A total of 22.5% of patients received systemic glucocorticoids simultaneously, which reduced the time to complete symptom relief. Furthermore, glucocorticoids combined with itraconazole had better treatment efficacy, with a higher rate and shorter time to achieving mycological cure. CONCLUSIONS Kerion often affects preschoolers and leads to serious sequelae, with AD, animal contact, and endothrix infection as potential risk factors. Glucocorticoids, especially those combined with itraconazole, had better treatment efficacy.
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Affiliation(s)
- Ruixin Deng
- Department of Dermatology and Venereology, Peking University First Hospital, National Clinical Research Centre for Skin and Immune Diseases, Beijing Key Laboratory of Molecular Diagnosis on Dermatoses, Beijing, China
| | - Xiaoqing Chen
- Department of Dermatology and Venereology, Peking University First Hospital, National Clinical Research Centre for Skin and Immune Diseases, Beijing Key Laboratory of Molecular Diagnosis on Dermatoses, Beijing, China
| | - Dongyan Zheng
- Department of Dermatology and Venereology, The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Yuanyuan Xiao
- Department of Dermatology, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing, China
| | - Bilin Dong
- Department of Dermatology, Wuhan No. 1 Hospital, Wuhan, China
| | - Cunwei Cao
- Department of Dermatology and Venereology, The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Lin Ma
- Department of Dermatology, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing, China
| | - Zhongsheng Tong
- Department of Dermatology, Wuhan No. 1 Hospital, Wuhan, China
| | - Min Zhu
- Department of Dermatology, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China
| | - Zehu Liu
- Department of Dermatology, Hangzhou Third People's Hospital, Affiliated Hangzhou Dermatology Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Sha Lu
- Department of Dermatology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
| | - Meng Fu
- Department of Dermatology, Xijing Hospital, Xi'an, China
| | - Yun Jin
- Department of Dermatology, Dermatology Hospital of Jiangxi Province, Nanchang, China
| | - Bin Yin
- Department of Dermatology, Chengdu Second People's Hospital, Chengdu, China
| | - Fuqiu Li
- Department of Dermatology, The Second Hospital of Jilin University, Changchun, China
| | - Xiaofang Li
- Institute of Dermatology, Chinese Academy of Medical Sciences and Peking Union Medical College, Nanjing, China
| | - Palida Abliz
- Department of Dermatology, The First Affiliated Hospital of Xinjiang Medical University, Urumqi, China
| | - Hongfang Liu
- Department of Dermatology, Dermatology Hospital of Southern Medical University, Guangzhou, China
| | - Yu Zhang
- Department of Dermatology, Tianjin Academy of Traditional Chinese Medicine Affiliated Hospital, Tianjin, China
| | - Nan Yu
- Department of Dermatology, General Hospital of Ningxia Medical University, Yinchuan, China
| | - Weiwei Wu
- Department of Dermatology, The Fifth People's Hospital of Hainan Province, Haikou, China
| | - Xincai Xiong
- Department of Dermatology, Affiliated Hospital of North Sichuan Medical College, Nanchong, China
| | - Jingsi Zeng
- Department of Dermatology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Huaiqiu Huang
- Department of Dermatology and Venereology, The Third Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Yanping Jiang
- Department of Dermatology, The Affiliated Hospital of Guizhou Medical University, Guiyang, China
| | - Guanzhi Chen
- Department of Dermatology, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Weihua Pan
- Department of Dermatology, Shanghai Changzheng Hospital, Naval Military Medical University, Shanghai, China
| | - Hong Sang
- Department of Dermatology, Jinling Hospital, Medical School of Nanjing University, Nanjing, China
| | - Ying Wang
- Department of Dermatology, Changhai Hospital of Shanghai, Shanghai, China
| | - Yun Guo
- Department of Dermatology, The Second Affiliated Hospital of Kunming Medical University, Kunming, China
| | - Dongmei Shi
- Department of Dermatology, Jining First People's Hospital, Jining, China
| | - Jianxun Yang
- Department of Dermatology, The Second Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Yuping Ran
- Department of Dermatology, West China Hospital, Sichuan University, Chengdu, China
| | - Jin Hu
- Department of Dermatology, The Affiliated Children's Hospital of Capital Institute of Pediatrics, Beijing, China
| | | | - Shuang Bai
- The Affiliated Hospital of Inner Mongolia Medical University, Huhhot, China
| | - Jin Yu
- Department of Dermatology and Venereology, Peking University First Hospital, National Clinical Research Centre for Skin and Immune Diseases, Beijing Key Laboratory of Molecular Diagnosis on Dermatoses, Beijing, China
| | - Xiaowen Wang
- Department of Dermatology and Venereology, Peking University First Hospital, National Clinical Research Centre for Skin and Immune Diseases, Beijing Key Laboratory of Molecular Diagnosis on Dermatoses, Beijing, China
| | - Ruoyu Li
- Department of Dermatology and Venereology, Peking University First Hospital, National Clinical Research Centre for Skin and Immune Diseases, Beijing Key Laboratory of Molecular Diagnosis on Dermatoses, Beijing, China
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Godse R, Rodriguez O, Ayoade KO, Rubin AI. Update on nail unit histopathology. Hum Pathol 2023; 140:214-232. [PMID: 36921726 DOI: 10.1016/j.humpath.2023.03.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2023] [Accepted: 03/08/2023] [Indexed: 03/18/2023]
Abstract
Histopathologic evaluation of the nail unit is an essential component in the diagnosis of nail unit disorders. This review highlights recent updates in nail unit histopathology and discusses literature covering a wide range of nail disorders including melanoma/melanocytic lesions, squamous cell carcinoma, onychomatricoma, onychopapilloma, onychomycosis, lichen planus, and other inflammatory conditions. Herein we also discuss recent literature on nail clipping histopathology, a useful and noninvasive diagnostic tool that continues to grow in popularity and importance to both dermatologists and dermatopathologists.
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Affiliation(s)
- Rama Godse
- Department of Dermatology, Hospital of the University of Pennsylvania, Philadelphia, PA, USA.
| | - Olaf Rodriguez
- Department of Dermatology, Hospital of the University of Pennsylvania, Philadelphia, PA, USA
| | - Katherine Omueti Ayoade
- Department of Dermatology, Hospital of the University of Pennsylvania, Philadelphia, PA, USA
| | - Adam I Rubin
- Department of Dermatology, Hospital of the University of Pennsylvania, Philadelphia, PA, USA
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Luethy PM. Point-of-Care Testing for the Diagnosis of Fungal Infections. Clin Lab Med 2023; 43:209-220. [PMID: 37169443 DOI: 10.1016/j.cll.2023.02.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/17/2023]
Abstract
Invasive fungal infections are increasing worldwide due to factors such as climate change and immunomodulating therapies. Unfortunately, the detection of these infections is limited due to the low sensitivity and long periods required for laboratory testing. Point-of-care testing could lead to more rapid diagnosis of these often devasting infections. However, there are currently no true point-of-care tests on the market for the detection of fungi. In this article, the current state of fungal antigen and molecular testing is reviewed, with commentary on the potential for development and use in the point-of-care setting.
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6
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Powell J, Porter E, Rafferty S, Field S, O'Connell NH, Dunne CP. Dermatology mycology diagnostics in Ireland: National deficits identified in 2022 that are relevant internationally. Mycoses 2023; 66:249-257. [PMID: 36448403 PMCID: PMC10107536 DOI: 10.1111/myc.13549] [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: 10/07/2022] [Revised: 11/18/2022] [Accepted: 11/22/2022] [Indexed: 12/05/2022]
Abstract
BACKGROUND Conventional testing methods for dermatophytes are time-consuming, and resource limitations in our institution have prompted curtailed access to these diagnostics. OBJECTIVES Evaluation of our hospital's dermatological mycology diagnostic services and similar services nationally. METHODS This was a retrospective observational study on skin, hair and nail mycology samples in our institution comparing twenty five-year periods (2011-2015 and 2016-2021), including analysis of dermatology clinic data and correspondence related to fungal infection. A survey of national public hospitals' laboratories was conducted to evaluate their mycology testing capabilities. RESULTS The total 5 year test count prior to curtailment was 4851 specimens comprising 90% (n = 4344) from general practice and 6% (n = 290) from dermatology clinics. For the 5 years post curtailment, 64.5% (582/903) of specimens were from dermatology clinics. Dermatology clinic data demonstrated doubling of attendances (for all conditions) and of correspondence related to fungal infection. During this time also, national dermatological antifungal purchasing increased 11%. Ten of 28 Irish public hospital laboratories reported the provision of in-house dermatological mycology testing, and none had routine availability of susceptibility or molecular testing of dermatophytes. CONCLUSION This study is the first to report an appraisal of dermatological fungal diagnostic services in Ireland. Insufficient testing capacity implies that patients are either being treated for fungal infection without appropriate diagnostic confirmation, or being left untreated because of the lack of access to diagnostics. The introduction of molecular detection methods and susceptibility systems would enhance testing capabilities and reduce the requirement for the external referral.
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Affiliation(s)
- James Powell
- Department of Microbiology, University Hospital Limerick, Limerick, Ireland.,School of Medicine and Centre for Interventions in Infection, Inflammation, and Immunity (4i), University of Limerick, Limerick, Ireland
| | - Emma Porter
- Department of Dermatology, University Hospital Limerick, Limerick, Ireland
| | - Siobhan Rafferty
- Department of Dermatology, University Hospital Limerick, Limerick, Ireland
| | - Sinead Field
- Department of Dermatology, University Hospital Limerick, Limerick, Ireland
| | - Nuala H O'Connell
- Department of Microbiology, University Hospital Limerick, Limerick, Ireland.,School of Medicine and Centre for Interventions in Infection, Inflammation, and Immunity (4i), University of Limerick, Limerick, Ireland
| | - Colum P Dunne
- School of Medicine and Centre for Interventions in Infection, Inflammation, and Immunity (4i), University of Limerick, Limerick, Ireland
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7
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Hui X, Mo XH, Yang LJ, Yang H, Tan JW, Yu Q, Zhang PF, Tan F. Comparison of Samples of Blister Fluid and Scales in the diagnosis of dermatomycosis. Mycoses 2022; 65:969-975. [PMID: 35815924 DOI: 10.1111/myc.13494] [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: 02/08/2022] [Revised: 06/30/2022] [Accepted: 07/06/2022] [Indexed: 11/28/2022]
Abstract
BACKGROUND The successful diagnosis of dermatomycosis depends on specimen collection. Dermatomycosis is sampled mainly for scales, but there is a lack of research on specimens of blister fluid. OBJECTIVES To explore whether blister fluid can diagnose dermatomycosis and compare blister fluid and scale specimens for dermatomycosis diagnosis. METHODS From April to July 2021, we prospectively gathered 34 patients who needed to meet all inclusion criteria simultaneously and collected their blister fluid and scales as specimens. The two samples were tested by fluorescent stain microscopy, fungal culture, and PCR, and the diagnosis results were compared. RESULTS The blister fluid sample's sensitivity, specificity, and accuracy were 90%, 100%, and 94.1%, respectively, whereas the scales sample were 60%, 100%, and 76.5%, respectively. The positive likelihood ratios were>10 for both blister fluid and scales specimen, and the negative likelihood ratios were not < 0.1. On the Youden's index, the blister fluid specimen was 90%, and the scales specimen was 60%. As for the diagnostic odds ratio, both of them were >1. By fungal culture, we detected 14 cases of fungi in blister fluid and eight in scales. On PCR, 22 cases of fungi in blister fluid and ten in scales were identified. CONCLUSIONS This study demonstrated that a sample of blister fluid had better sensitivity, accuracy, and Youden's index in diagnosing dermatomycosis with blister fluid. Collection of blister fluid might compensate for the inadequacy of collecting only scales specimens for mycological testing.
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Affiliation(s)
- Xia Hui
- Clinical College of Shanghai Skin Disease Hospital, Anhui Medical University, Shanghai, China.,Shanghai Skin Disease Hospital, School of Medicine, Tongji University, Shanghai, China
| | - Xiao Hui Mo
- Renji Hospital, Shanghai JiaoTong University, School of Medicine, Shanghai, China
| | - Lian Juan Yang
- Shanghai Skin Disease Hospital, School of Medicine, Tongji University, Shanghai, China
| | - Hong Yang
- Shanghai Skin Disease Hospital, School of Medicine, Tongji University, Shanghai, China
| | - Jing Wen Tan
- Shanghai Skin Disease Hospital, School of Medicine, Tongji University, Shanghai, China
| | - Qian Yu
- Shanghai Skin Disease Hospital, School of Medicine, Tongji University, Shanghai, China
| | - Peng Fei Zhang
- Shanghai Skin Disease Hospital, School of Medicine, Tongji University, Shanghai, China
| | - Fei Tan
- Clinical College of Shanghai Skin Disease Hospital, Anhui Medical University, Shanghai, China.,Shanghai Skin Disease Hospital, School of Medicine, Tongji University, Shanghai, China
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8
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Rajkumar A, Britton PN. Kerion: a great mimicker. Med J Aust 2022; 216:563-567. [DOI: 10.5694/mja2.51588] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2021] [Revised: 09/27/2021] [Accepted: 11/09/2021] [Indexed: 11/17/2022]
Affiliation(s)
| | - Philip N Britton
- Children’s Hospital at Westmead Sydney NSW
- University of Sydney Sydney NSW
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Faramarzi S, Motamedi M, Rezaei-Matehkolaei A, Aboutalebian S, Ansari S, Didehdar M, Bahadoran M, Mirhendi H. A simple multiplex polymerase chain reaction assay for rapid identification of the common pathogenic dermatophytes: Trichophyton interdigitale, Trichophyton rubrum, and Epidermophyton floccosum. Curr Med Mycol 2022; 7:1-7. [PMID: 35028478 PMCID: PMC8740852 DOI: 10.18502/cmm.7.2.7030] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2021] [Revised: 05/22/2021] [Accepted: 06/30/2021] [Indexed: 12/04/2022] Open
Abstract
Background and Purpose: The most common etiological agents of human dermatophytosis in various parts of the world are Trichophyton rubrum, Trichophyton interdigitale, and Epidermophyton floccosum.
The main aim of this study was to design and evaluate a simple and straightforward multiplex polymerase chain reaction (PCR) assay for reliable identification/differentiation of these species
in clinical isolates. Materials and Methods: The reliable sequences of several molecular targets of dermatophytes species were used to design a multiplex PCR for the identification of common pathogenic dermatophytes.
The isolates and clinical specimens examined in this study included seven standard strains of dermatophytes, 101 isolates of dermatophytes and non-dermatophyte molds/yeasts which
had already been identified by sequencing or PCR-restriction fragment length polymorphism (RFLP), and 155 clinical samples from patients suspected of cutaneous mycoses. Results: Species-specific primer pairs for T. rubrum and T. interdigitale/T. mentagrophytes were designed based on the sequence data of the translation elongation factor 1-alpha gene,
and the primers for E. floccosum targeted the specific sequence of the internal transcribed spacer region (ITS). The multiplex PCR successfully
detected T. rubrum, T. interdigitale/T. mentagrophytes, and E. floccosum strains that were identified by sequencing or PCR-RFLP. However, the primer pairs selected
for T. interdigitale/T. mentagrophytes cross-reacted with Trichophyton tonsurans. In testing the PCR system directly for clinical samples, the proportion of positive
multiplex PCR was higher than positive culture (68.1% vs. 55.4%, respectively). Conclusion: The multiplex assay could detect three common agents out of several causal agents of dermatophytosis, namely T. rubrum, T. interdigitale, and E. floccosum. Therefore, by adding
pan-dermatophyte primers it can be used as a comprehensive detection/identification test.
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Affiliation(s)
- Sama Faramarzi
- Department of Medical Parasitology and Mycology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Marjan Motamedi
- Department of Medical Parasitology and Mycology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Ali Rezaei-Matehkolaei
- Department of Medical Mycology, School of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Shima Aboutalebian
- Department of Medical Parasitology and Mycology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Saham Ansari
- Department of Medical Parasitology and Mycology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mojtaba Didehdar
- Department of Medical Parasitology and Mycology, School of Medicine, Arak University of Medical Sciences, Arak, Iran
| | - Mehran Bahadoran
- Department of Medical Parasitology and Mycology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Hossein Mirhendi
- Department of Medical Parasitology and Mycology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
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Real-Time PCR Assay for the Detection of Dermatophytes: Comparison between an In-House Method and a Commercial Kit for the Diagnosis of Dermatophytoses in Patients from Dakar, Senegal. J Fungi (Basel) 2021; 7:jof7110949. [PMID: 34829236 PMCID: PMC8624614 DOI: 10.3390/jof7110949] [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: 09/27/2021] [Revised: 11/05/2021] [Accepted: 11/08/2021] [Indexed: 12/15/2022] Open
Abstract
Background. PCR assays have been developed for the diagnosis of dermatophytes, yet data in African populations are scarce. Objective. This study aimed to compare two PCR assays for the diagnosis of dermatophytosis in outpatients at the Aristide Le Dantec University Hospital in Dakar, Senegal. Patients and methods. A total of 105 samples, including 24 skin, 19 nail and 62 hair samples collected from 99 patients were included in this study. Each sample was subjected to conventional diagnosis (CD), including direct microscopy and culture, and two real-time PCR assays: one in-house (IH)-PCR, used at the University Hospital of Marseille and the Eurobio Scientific commercial kit (CK): designed for the specific detection of six dermatophytes not including Microsporum audouinii. Results. Of the 105 specimens, 24.8%, 36.2% and 20% were positive by CD, IH-PCR and CK-PCR, respectively. The IH-PCR and CK-PCR exhibited 88.9% and 65.4% sensitivity, respectively. With a 36.6 diagnostic odd ratio and 1.41 needed to diagnose, the IH-PCR displayed better diagnostic indices than the CK-PCR. It is notable that, when considering the species that it claims to detect, when it came to skin and nail samples, CK-PCR sensitivity increased to 77%. Conclusions. The pan-dermatophyte IH-PCR performed better in the diagnosis of dermatophytosis in this African population than the CK-PCR, which is not designed to detect M. audouinii. Nevertheless, both assays exhibited similarly good diagnostic indices for tinea corporis and tinea unguium, both of which are localisations where M. audouinii is more rarely involved than in tinea capitis.
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Multiplex RT-PCR provides improved diagnosis of skin and nail dermatophyte infections compared to microscopy and culture: a laboratory study and review of the literature. Diagn Microbiol Infect Dis 2021; 101:115413. [PMID: 34256251 DOI: 10.1016/j.diagmicrobio.2021.115413] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 04/18/2021] [Accepted: 04/19/2021] [Indexed: 11/23/2022]
Abstract
Dermatophytes are the most common cause of superficial mycosis, estimated to affect 20% to 25% of the general population. We assessed the performance of a novel real-time polymerase chain reaction (RT-PCR) multiplex assay for diagnosis of dermatophytosis. To evaluate sensitivity and specificity, 10 known bacteria and 10 known fungi commonly found on skin, as well as 105 samples with culture confirmed dermatophytosis were tested using Dermatophyte and Fungi assay (AusDiagnostics, Sydney, Australia), a novel multiplex assay for diagnosis of dermatophytosis in skin and nail. This was followed by prospective evaluation of 195 clinical samples for dermatophytosis by both conventional methods and RT-PCR. RT-PCR showed almost two-fold higher sensitivity and high specificity in the diagnosis of skin and nail dermatophytosis compared to traditional microscopy and culture. In addition, RT-PCR demonstrated markedly reduced turnaround time from 4 to 6 weeks to 4 to 6 hours and ability for high throughput.
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