|Year : 2017 | Volume
| Issue : 3 | Page : 3-11
Overview and update on the laboratory diagnosis of dermatophytosis
Shivaprakash M Rudramurthy, Dipika Shaw
Department of Medical Microbiology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
|Date of Web Publication||10-Oct-2017|
Shivaprakash M Rudramurthy
Department of Medical Microbiology, Division of Mycology, Postgraduate Institute of Medical Education and Research, Chandigarh
Source of Support: None, Conflict of Interest: None
Dermatophytosis, caused by dermatophytes is becoming difficult to treat due to various reasons. Accurate diagnosis is essential for the accurate management of this infection and prevention of relapse or recurrence. Although this condition is easy to diagnose clinically, due to overlapping signs and symptoms of few dermatological conditions it may be misdiagnosed necessitating laboratory confirmation. Isolation, identification of the dermatophytes and the antifungal susceptible profile may further help to initiate appropriate antifungal agent. The classical conventional techniques such as direct microscopic examination and isolation of fungi from the clinical specimens are still considered as an important modality of diagnosis. With the rise of the molecular era, molecular techniques are increasingly being applied to diagnose dermatophytosis and identify the dermatophytes. The present review provides an overview and update on the laboratory diagnosis of dermatophytosis.
Keywords: Conventional diagnosis, dermatophytes, dermatophytosis, laboratory diagnosis, molecular diagnosis
|How to cite this article:|
Rudramurthy SM, Shaw D. Overview and update on the laboratory diagnosis of dermatophytosis. Clin Dermatol Rev 2017;1, Suppl S1:3-11
| Introduction|| |
Superficial fungal infections affect millions of people worldwide with an estimated lifetime risk of 20%–25%. One of the major causes of these infections include dermatophytes, nondermatophytic moulds (NDMs), and yeasts. All dermatophytes belong to three genera Trichophyton, Microsporum, and Epidermophyton. Based on the natural habitat, these fungi can be differentiated into geophilic, zoophilic, and anthropophilic species that are acquired from soil, animals, and human, respectively. The various clinical manifestation of dermatophytosis has been described. Although the disease can be diagnosed based on typical clinical presentation, laboratory confirmation may be essential for those with rare presentations. In addition, in view of the present problem of relapse or recurrences in India, laboratory diagnosis in terms of isolation, identification and in vitro susceptibility testing is gaining importance. For optimal management of the onychomycosis, identification of causative agent plays an important role as the treatment with specific antifungal agents varies for the dermatophytes and NDMs or yeast.
The efficiency of the laboratory diagnosis of dermatophytosis depends on the quality of samples collected. Few important attributes that should be considered while collecting the samples are (i) cleaning the lesion site with 70% alcohol to remove the contaminants and (ii) sample collection before initiating systemic treatment and if already applying topical antifungals or on oral antifungals, abstinence for at least 15 days or 3 months respectively is essential before sample collection. Samples from skin should include epidermal scales usually collected from the advancing edge of the lesions using sterile dermal blunt curette (Brocq's curette), scalpel blades, or vaccinostyles. Whereas, nail samples are collected near the area of nail bed where viable fungal hyphae are usually present. While collecting infected hair for diagnosis, it is important to include the hair follicle to increase the chance of detection and isolation. Hence, hairs should be plucked from the basal part using sterile forceps and not clipped.
| Conventional Diagnostic Methods|| |
Examination of the clinical specimen using microscope is one of the simple and rapid screening techniques that allow the clinician to initiate antifungal therapy for dermatophytosis. Direct microscopic visualization requires the addition of clearing agent to digest keratin from the sample. A variety of clearing agents such as 10% or 20% potassium hydroxide (KOH) with or without dimethyl sulfoxide, 10% sodium hydroxide, Amann's chloral lactophenol, and detergents such as sodium dodecyl sulfate (SDS) can be used. KOH is a simplest and low-cost method for keratin dissociation used in every mycology laboratory. As the KOH do not stain the fungi and can be visualized only based on the difference in the refraction, detection of fungi in this preparation is difficult for the beginners and requires some amount of expertise. To provide the contrast, and increase the chance of detection and sensitivity of direct microscopy, various stains such as cotton blue C4B (Bacti-Lab Inc., RAL or Bio-Rad, associated with lactic acid and phenol) or Blue–Black Ink permanent (Parker Quink), or chlorazol black E (CBE; Sigma-Aldrich) stain which imparts deep blue or black color to fungal element are used. In addition, other stains such as Periodic acid-Schiff (PAS) which stains polysaccharide glycosaminoglycans, Congo red which stains ß-D-glucans and fluorochromes such as calcofluor white (CW; Fluorescent brightener 28, Sigma-Aldrich), BlankophorPFlussig (Bayer) or Uvitex 2B (Fungiqual A, Ciba Corning) which binds to chitin of the fungal cell wall have been evaluated and found to be beneficial. Mycetocolor® and Mycetfluo® are commercial reagents that contain Congo red and calcofluor respectively along with SDS as a clearing agent. Recently, Pihet et al. evaluated four different staining techniques, KOH with chlorazol black, charcoal-lactophenol, Mycetocolor® and Mycetfluo® and showed that performance of Mycetfluo® was better (57%) and statistically significant when compared to other three staining techniques (42%) for detecting fungal elements in skin, hair, and nail samples. Histological examination using stains like PAS or Gomoris methenamine silver on which the fungi appears red or gray black respectively also helps in the diagnosis especially for the examination of the nail specimen. Cyanoacrylate surface skin scrapping is a simple strip biopsy test performed by removing the uniform thickness of stratum corneum with the adhesive. This test has been evaluated for the detection of dermatophytes from the skin specimen and has shown the sensitivity of 62% with high negative predictive value of 92%. However, the main disadvantage of this technique is that it cannot be applied for hair or nail samples.
Isolation and identification of the etiological agent responsible for dermatophytosis are essential as the treatment regimens may differ for different dermatophyte species for example - Trichophyton tonsurans in tinea capitis tends to require shorter duration of therapy than that caused by Microsporum canis; onychomycosis due to nondermatophyte mold may not respond to the standard therapy used for dermatophytosis. Sabouraud's dextrose agar or potato dextrose agar supplemented with antibiotics (chloramphenicol ± gentamicin), and cycloheximide are generally used for the primary isolation of fungi from a clinical specimen. Cultures are usually incubated at 20°C–25°C for 4–6 weeks, but higher incubation temperatures of 30°C–32°C may be required if Trichophyton verrucosum is suspected. Dermatophyte test medium was developed by Taplin as a selective and differential medium for detection and identification of dermatophytes. The growth of dermatophytes on this media may be presumptively identified based on gross morphology and the production of alkaline metabolites, which raise the pH and cause the phenol red indicator to change the color of the medium from yellow to pink-red. In addition, specialized isolation media like casamino acids-erythritol albumin agar may help for isolation of the dermatophytes especially when the sample is contaminated with bacteria or yeast. Bromocresol purple casein yeast extract agar may be used for the rapid identification of T. verrucosum. Spores are essential for the morphological identification of dermatophytes. Most of the dermatophytes take a longer time to sporulate or sometimes do not sporulate on primary isolation media, hence, it is essential to induce spores on the sporulation media to proceed for morphological identification. Many sporulation media such as potato dextrose agar, Borelli lactrimel agar, pablum cereal, brain heart infusion agar, Baxter's medium, Takasio medium, malt agar, or water agar which stimulate conidiation and pigment production of dermatophytes may be used. Apart from that, special culture media that can differentiate different species and genus of dermatophytes are bromocresol purple milk solid glucose agar (turns violet color in the presence of Trichophyton interdigitale, differentiating it from Trichophyton rubrum and Microsporum persicolor); polished rice grains that can differentiate Microsporum audouinii (brownish pigment) from M. canis (yellow pigment);, urea indole broth or Christensen's urea agar medium that can differentiate Trichophyton mentagrophytes from T. rubrum and Trichophyton soudanense from urease negative organism.In vitro hair perforation test can differentiate T. rubrum (no perforating organs) from T. mentagrophytes and M. canis (positive test) from M. audouinii or M. equinum (negative test). Comparative evaluation of direct microscopy and culture from the clinical samples is summarized in [Table 1].
|Table 1: Review of performance of direct microscopy and culture from skin, hair, and nail samples|
Click here to view
The rate of isolation of the fungi from the clinical specimen has been found to be lesser than the positivity rate of direct microscopic examination. These discrepancies in the result of direct microscopy and culture has been attributed to several factors such as inadequate quantity of sample, presence of nonviable fungal hyphae, and antifungal treatment before sample collection. The presence of antifungals in the epidermal layer of skin inhibits the growth of the fungi. A medium containing lecithin and polysorbate 80 has been developed and being used to minimize the carryover effect of antifungals., Direct microscopy has a limitation that it only detects the presence or absence of fungal element but cannot help in the differentiation of the different species. Even after successful isolation of the dermatophytes from the clinical specimen, identification is difficult due to morphological similarities shared between species necessitating molecular techniques.
| Molecular Diagnostic Methods|| |
Isolation and identification of dermatophytes from the clinical samples are considered as a gold standard method for diagnosis of dermatophytosis. However, the dermatophyte usually takes long time to grow in culture and sporulate leading to delayed diagnosis. Rapid diagnosis and accurate identification of dermatophytes helps in successful management. Nucleic acid-based molecular methods are increasingly being employed in the clinical microbiological laboratory for rapid and specific identification of the fungi as well as for the detection of etiological agent directly from the clinical specimen.
Extraction of the DNA from the clinical specimens can be done by phenol–chloroform method or using commercially available DNA extraction kit. Before DNA extraction step, keratin from the clinical sample should be disrupted which can be achieved by mechanical method or enzymatic digestion of keratin with proteinase K or nonenzymatic disruption by Na2S solution. As very low quantity of the fungal DNA is expected from clinical samples, different approaches have been used to increase the yield of DNA. The sensitivity of detection depends on selection of the target DNA for amplification, and application of techniques that could detect the specific amplicon. Molecular diagnoses for rapid detection of etiological agent from the clinical specimens may be done either by conventional polymerase chain reaction (PCR) or by real-time PCR.
Conventional PCR is one of the widely used, simple and inexpensive tool for detection of a particular species with specific primers and its interpretation is mainly based on amplicon size in agarose gel. The identification of an organism is achieved using variety of primers such as species specific primer (amplify only the species of interest), pan dermatophyte primer (amplifies the DNA from all dermatophytes), or pan fungal primer (amplifies the DNA of any fungal agent which usually targets internal transcribed region [ITS] or 28S region of ribosomal DNA sequence or gene encoding topoisomerase II, or chitin synthase I [CHS I])., Brillowska-Dabrowska et al. developed the PCR test using ITS primers designed to amplify 302 bp amplicon of Trichophyton species and 279 bp amplicon of Microsporum species. Of the 58 isolates tested, they could successfully identify 42 isolates including 35/35 - Trichophyton isolates belonging to ten different species and 3/3 - M. canis and 4/4 - M. audouinii samples. They could not identify 2 - Epidermophyton floccosum, 11 - Microsporum gypseum, and 3 - M. persicolor. The same group further developed multiplex PCR test for detection of dermatophytes from tinea unguium cases by adding species specific primers. Multiplex PCR based on CHS I and ITS region for identification of T. rubrum and T. mentagrophytes showed a sensitivity of 97% which was higher (81.1%) than the conventional method. In many countries, duplex PCR has been used for detection of T. rubrum from onychomycosis and tinea pedis cases.,,, Kondori et al. evaluated the duplex PCR and reported positivity rate of 44% for dermatophytes compared to 34% by culture, the sensitivity and specificity was 94% and 85%, respectively. Garg et al. performed pan-dermatophyte nested PCR targeting CHS I and ITS and showed a sensitivity of 83.8% which was far higher than the KOH wet mount examination. They concluded that this method should be considered as the gold standard method for the diagnosis of onychomycosis., Although nested PCR has high sensitivity, this test cannot be recommended for clinical diagnosis because of increased chance of contamination due to two successive amplifications steps involved in the procedure.
Real-time PCR is a rapid and sensitive approach to detect an organism directly from clinical samples. As real-time PCR assay is conducted in a closed tube system, it limits the risk of contamination and helps in detection of multiple species of dermatophytes using different species-specific probes. Arabatzis et al. detected and identified different dermatophytes from the clinical samples by real-time PCR using ITS primers. Alexander et al., mainly targeted T. rubrum using T. rubrum specific primers and a probe whereas Bergmans et al., could differentiate 11 dermatophytes within 72 h in a single real-time PCR reaction with melt curve analysis., Real-time PCR could detect both dermatophytes and nondermatophytes with a sensitivity of 97% when compared with culture. The concordance between the culture and the real-time PCR in identifying the dermatophytes to the species and genus level was 94.3% and 97.4%, respectively. These results suggests that real-time PCR technique can be applied successfully for the diagnosis of dermatophytosis as an alternative to the classical diagnostic methods.,
Post-PCR techniques like PCR-ELISA has been reported to be highly sensitive for detection of dermatophytes to the species level from the clinical specimens. Five common species of dermatophytes including T. rubrum, T. interdigitale, T. violaceum, M. canis, and Epidermophyton floccosum was directly detected from the clinical samples by PCR ELISA by amplifying topoisomerase II gene and detection by hybridization using digoxigenin labeled probes. PCR ELISA from onychomycosis cases showed sensitivity of 79.0% and specificity of 85.5% in comparison with conventional method., Sato et al. developed a simple PCR-based DNA microarray (PCR DM) technique to identify 26 reference strains of clinically important fungi. They found that 92% of 106 microscopic positive onychomycosis cases could be identified by PCR DM. Further, PCR reverse line blot assay provide rapid detection and identification of dermatophytes within 24 h from clinical samples. PCR terminal restriction fragment length polymorphism is simple and reliable for routine diagnosis of etiological agent identification from onychomycosis. This approach could detect fungi in 74% (162/219) of culture negative samples and can be performed with the minimum amount of nail sample (20–100 mg).
In view of the morphological similarities or due to less or rare production of macroconidia and/or microconidia most of the dermatophytes remains unidentified by classical conventional methods. [Table 2] summarizes the complete comparison of molecular diagnostic technique with conventional diagnostic methods. Yüksel and Ilkit, evaluated 64 dermatophyte isolates, including 35 isolates which rarely produce macroconidia, by real-time PCR and showed accurate identification of ten taxonomically distinct dermatophytes with 100% sensitivity. At present, sequencing of the ITS region of rDNA is considered as a gold standard for the identification of the dermatophytes,,, However, ITS-rDNA sequence based identification is limited as it has certain limitation such as small number of nucleotide differences observed in several ecologically and phenotypically separated Trichophyton species.,,, Hence, other genetic markers such as partial beta tubulin, 60S ribosomal protein L10, calmodulin are being attempted to discriminate between closely related species of dermatophytes. Sequencing method also helps in detection of novel species (e.g., Trichophyton bullosum and Microsporum mirabile was described based on sequencing)
|Table 2: Review of molecular techniques in comparison with conventional methods|
Click here to view
Matrix-assisted laser desorption ionization time of flight (MALDI-TOF) mass spectrometry is relatively a new technique that is being used in the microbiology laboratory for the rapid identification of the microorganisms. This technique has been evaluated for the identification of dermatophytes and the results have revealed that this technique is accurate and comparable to the sequencing technique. The recent review on MALDI-TOF-based identification of dermatophytosis recommends the use of formic acid extraction step instead of direct mounting to improve the quality of the peaks obtained and its analysis. The major limitation of this technique is inadequate representation of dermatophyte species in reference spectrum libraries of different commercial systems. This limitation can be overcome by the laboratories by developing an in-house reference library for inter- and intra-specific dermatophyte diversity.,,
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| References|| |
Oke OO, Onayemi O, Olasode OA, Omisore AG, Oninla OA. The prevalence and pattern of superficial fungal infections among school children in ile-ife, South-Western Nigeria. Dermatol Res Pract 2014;2014:842917.
Weitzman I, Summerbell RC. The dermatophytes. Clin Microbiol Rev 1995;8:240-59.
Pihet M, Le Govic Y. Reappraisal of conventional diagnosis for dermatophytes. Mycopathologia 2017;182:169-80.
Robert R, Pihet M. Conventional methods for the diagnosis of dermatophytosis. Mycopathologia 2008;166:295-306.
Pihet M, Clément N, Kauffmann-Lacroix C, Nail-Billaud S, Marot A, Pilon F, et al.
Diagnosis of dermatophytosis: An evaluation of direct examination using MycetColor® and MycetFluo®. Diagn Microbiol Infect Dis 2015;83:170-4.
Lousbergh D, Buntinx F, Piérard G. Diagnosing dermatomycosis in general practice. Fam Pract 1999;16:611-5.
Salkin IF, Padhye AA, Kemna ME. A new medium for the presumptive identification of dermatophytes. J Clin Microbiol 1997;35:2660-2.
Summerbell RC, Rosenthal SA, Kane J. Rapid method for differentiation of Trichophyton rubrum
, Trichophyton mentagrophytes
, and related dermatophyte species. J Clin Microbiol 1988;26:2279-82.
Nakashima T, Nozawa A, Ito T, Majima T, Yamaguchi H. Development of a new medium useful for the recovery of dermatophytes from clinical specimens by minimizing the carryover effect of antifungal agents. Microbiol Immunol 2002;46:83-8.
Cafarchia C, Iatta R, Latrofa MS, Gräser Y, Otranto D. Molecular epidemiology, phylogeny and evolution of dermatophytes. Infect Genet Evol 2013;20:336-51.
Liu D, Coloe S, Baird R, Pedersen J. Application of PCR to the identification of dermatophyte fungi. J Med Microbiol 2000;49:493-7.
Hayette M-P, Sacheli R. Dermatophytosis, trends in epidemiology and diagnostic approach. Curr Fungal Infect Rep 2015;9:164-79.
Faggi E, Pini G, Campisi E, Bertellini C, Difonzo E, Mancianti F, et al.
Application of PCR to distinguish common species of dermatophytes. J Clin Microbiol 2001;39:3382-5.
Jensen RH, Arendrup MC. Molecular diagnosis of dermatophyte infections. Curr Opin Infect Dis 2012;25:126-34.
Verrier J, Monod M. Diagnosis of dermatophytosis using molecular biology. Mycopathologia 2017;182:193-202.
Nenoff P, Krüger C, Schaller J, Ginter-Hanselmayer G, Schulte-Beerbühl R, Tietz HJ, et al.
Mycology – An update part 2: Dermatomycoses: Clinical picture and diagnostics. J Dtsch Dermatol Ges 2014;12:749-77.
Brillowska-Dabrowska A, Swierkowska A, Lindhardt Saunte DM, Arendrup MC. Diagnostic PCR tests for Microsporum audouinii
, M. canis
infections. Med Mycol 2010;48:486-90.
Brillowska-Dabrowska A, Nielsen SS, Nielsen HV, Arendrup MC. Optimized 5-hour multiplex PCR test for the detection of tinea unguium: Performance in a routine PCR laboratory. Med Mycol 2010;48:828-31.
Kondori N, Abrahamsson AL, Ataollahy N, Wennerås C. Comparison of a new commercial test, Dermatophyte-PCR kit, with conventional methods for rapid detection and identifi cation of Trichophyton rubrum in nail specimens. Med Mycol 2010;48:1005-8.
Bergmans AM, van der Ent M, Klaassen A, Böhm N, Andriesse GI, Wintermans RG, et al
. Evaluation of a single-tube real-time PCR for detection and identifi cation of 11 dermatophyte species in clinical material. Clin Microbiol Infect 2010;16:704-10.
Beifuss B, Bezold G, Gottlöber P, Borelli C, Wagener J, Schaller M, et al
. Direct detection of fi ve common dermatophyte species in clinical samples using a rapid and sensitive 24-h PCR-ELISA technique open to protocol transfer. Mycoses 2011;54:137-45.
Sato T, Takayanagi A, Nagao K, Tomatsu N, Fukui T, Kawaguchi M, et al
. Simple PCR-based DNA microarray system to identify human pathogenic fungi in skin. J Clin Microbiol 2010;48:2357-64.
Garg J, Tilak R, Singh S, Gulati AK, Garg A, Prakash P, et al.
Evaluation of pan-dermatophyte nested PCR in diagnosis of onychomycosis. J Clin Microbiol 2007;45:3443-5.
Garg J, Tilak R, Garg A, Prakash P, Gulati AK, Nath G, et al.
Rapid detection of dermatophytes from skin and hair. BMC Res Notes 2009;2:60.
Petinataud D, Berger S, Contet-Audonneau N, Machouart M. Molecular diagnosis of onychomycosis. J Mycol Med 2014;24:287-95.
Arabatzis M, Bruijnesteijn van Coppenraet LE, Kuijper EJ, de Hoog GS, Lavrijsen AP, Templeton K, et al
. Diagnosis of common dermatophyte infections by a novel multiplex real-time polymerase chain reaction detection/identifi cation scheme. Br J Dermatol 2007;157:681-9.
Alexander CL, Shankland GS, Carman W, Williams C. Introduction of a dermatophyte polymerase chain reaction assay to the diagnostic mycology service in scotland. Br J Dermatol 2011;164:966-72.
Sharma R, Rajak RC, Pandey AK, Gräser Y. Internal transcribed spacer (ITS) of rDNA of appendaged and non-appendaged strains of Microsporum gypseum
reveals Microsporum appendiculatum
as its synonym. Antonie Van Leeuwenhoek 2006;89:197-202.
Gräser Y, Kuijpers AF, Presber W, de Hoog GS. Molecular taxonomy of the Trichophyton rubrum
complex. J Clin Microbiol 2000;38:3329-36.
Makimura K, Tamura Y, Mochizuki T, Hasegawa A, Tajiri Y, Hanazawa R, et al
. Phylogenetic classification and species identification of dermatophyte strains based on DNA sequences of nuclear ribosomal internal transcribed spacer 1 regions. J Clin Microbiol 1999;37:920-4.
Bergmans AM, Schouls LM, van der Ent M, Klaassen A, Böhm N, Wintermans RG, et al
. Validation of PCR-reverse line blot, a method for rapid detection and identification of nine dermatophyte species in nail, skin and hair samples. Clin Microbiol Infect 2008;14:778-88
Verrier J, Pronina M, Peter C, Bontems O, Fratti M, Salamin K, et al
. Identification of infectious agents in onychomycoses by PCR-terminal restriction fragment length polymorphism. J Clin Microbiol 2012;50:553-61
Yüksel T, Ilkit M. Identification of rare macroconidia-producing dermatophytic fungi by real-time PCR. Med Mycol 2012;50:346-52.
Gräser Y, El Fari M, Vilgalys R, Kuijpers AF, De Hoog GS, Presber W, et al
. Phylogeny and taxonomy of the family Arthrodermataceae (dermatophytes) using sequence analysis of the ribosomal ITS region. Med Mycol 1999;37:105-14.
Rezaei-Matehkolaei A, Mirhendi H, Makimura K, de Hoog GS, Satoh K, Najafzadeh MJ, et al
. Nucleotide sequence analysis of beta tubulin gene in a wide range of dermatophytes. Med Mycol 2014;52:674-88.
Mirhendi H, Makimura K, de Hoog GS, Rezaei-Matehkolaei A, Najafzadeh MJ, Umeda Y, et al
. Translation elongation factor 1-α gene as a potential taxonomic and identifi cation marker in dermatophytes. Med Mycol 2015;53:215-24.
Rezaei-Matehkolaei A, Makimura K, De Hoog GS, Shidfar MR, Satoh K, Najafzadeh MJ, et al
. Discrimination of Trichophyton tonsurans
and Trichophyton equinum
by PCR-RFLP and by β-tubulin and translation elongation factor 1-α sequencing. Med Mycol 2012;50:760-4.
Rezaei-Matehkolaei A, Makimura K, de Hoog GS, Shidfar MR, Satoh K, Najafzadeh MJ, et al
. Multilocus differentiation of the related dermatophytes Microsporum canis, Microsporum ferrugineum and Microsporum audouinii. J Med Microbiol 2012;61:57-63.
L'Ollivier C, Ranque S. MALDI-TOF-based dermatophyte identification. Mycopathologia 2017;182:183-92.
Prakash R, Prashanth HV, Ragunatha S, Kapoor M, Anitha TK, Krishnamurthy V, et al
. Comparative study of effi cacy, rapidity of detection, and cost-effectiveness of potassium hydroxide, calcofluor white, and Chicago sky blue stains in the diagnosis of dermatophytoses. Int J Dermatol 2016;55:e172-5.
Haghani I, Shokohi T, Hajheidari Z, Khalilian A, Aghili SR. Comparison of diagnostic methods in the evaluation of onychomycosis. Mycopathologia 2013;175:315-21.
Tambosis E, Lim C. A comparison of the contrast stains, Chicago blue, chlorazole black, and parker ink, for the rapid diagnosis of skin and nail infections. Int J Dermatol 2012;51:935-8.
Lim CS, Lim SL. New contrast stain for the rapid diagnosis of dermatophytic and candidal dermatomycoses. Arch Dermatol 2008;144:1228-9.
Shenoy MM, Teerthanath S, Karnaker VK, Girisha BS, Krishna Prasad MS, Pinto J, et al
. Comparison of potassium hydroxide mount and mycological culture with histopathologic examination using periodic acid-Schiff staining of the nail clippings in the diagnosis of onychomycosis. Indian J Dermatol Venereol Leprol 2008;74:226-9.
] [Full text]
Hamer EC, Moore CB, Denning DW. Comparison of two fluorescent whiteners, Calcofluor and Blankophor, for the detection of fungal elements in clinical specimens in the diagnostic laboratory. Clin Microbiol Infect 2006;12:181-4.
Abdelrahman T, Letscher Bru V, Waller J, Noacco G, Candolfi E. Dermatomycosis: Comparison of the performance of calcofluor and potassium hydroxide 30% for the direct examination of skin scrapings and nails. J Mycol Méd 2006;16:87-91.
Lilly KK, Koshnick RL, Grill JP, Khalil ZM, Nelson DB, Warshaw EM, et al
. Cost-effectiveness of diagnostic tests for toenail onychomycosis: A repeated-measure, single-blinded, cross-sectional evaluation of 7 diagnostic tests. J Am Acad Dermatol 2006;55:620-6.
Panasiti V, Borroni RG, Devirgiliis V, Rossi M, Fabbrizio L, Masciangelo R, et al
. Comparison of diagnostic methods in the diagnosis of dermatomycoses and onychomycoses. Mycoses 2006;49:26-9.
Scherer WP, Scherer MD. A comparison of results from two mycology laboratories for the diagnosis of onychomycosis: A study of 85 cases in a geriatric population. J Am Podiatr Med Assoc 2004;94:528-34.
Weinberg JM, Koestenblatt EK, Tutrone WD, Tishler HR, Najarian L. Comparison of diagnostic methods in the evaluation of onychomycosis. J Am Acad Dermatol 2003;49:193-7.
Reisberger EM, Abels C, Landthaler M, Szeimies RM. Histopathological diagnosis of onychomycosis by periodic acid-Schiff-stained nail clippings. Br J Dermatol 2003;148:749-54.
Elewski BE, Leyden J, Rinaldi MG, Atillasoy E. Office practice-based confirmation of onychomycosis: A US nationwide prospective survey. Arch Intern Med 2002;162:2133-8.
Borkowski P, Williams M, Holewinski J, Bakotic B. Onychomycosis: An analysis of 50 cases and a comparison of diagnostic techniques. J Am Podiatr Med Assoc 2001;91:351-5.
Pariser D, Opper C. An in-office diagnostic procedure to detect dermatophytes in a nationwide study of onychomycosis patients. Manag Care 2002;11:43-8, 50.
Lawry MA, Haneke E, Strobeck K, Martin S, Zimmer B, Romano PS, et al
. Methods for diagnosing onychomycosis: A comparative study and review of the literature. Arch Dermatol 2000;136:1112-6.
Scherer WP, Kinmon K. Dermatophyte test medium culture versus mycology laboratory analysis for suspected onychomycosis. A study of 100 cases in a geriatric population. J Am Podiatr Med Assoc 2000;90:450-9.
Kizny Gordon A, McIver C, Kim M, Murrell DF, Taylor P. Clinical application of a molecular assay for the detection of dermatophytosis and a novel non-invasive sampling technique. Pathology 2016;48:720-6.
Wang HY, Kim H, Choi EH, Lee H. Performance of the real fungus-ID kit based on multiplex RT-PCR assay for the rapid detection and identification of trichophyton spp. and microsporum spp. in clinical specimens with suspected dermatophyte infection. J Appl Microbiol 2016;120:234-47.
Gong J, Ran M, Wang X, Wan Z, Li R. Development and evaluation of a novel real-time PCR for pan-dermatophyte detection in nail specimens. Mycopathologia 2016;181:51-7.
Miao Z, Li S, Li D, Cai C, Cai Y. Rapid detection for rabbit-derived dermatophytes using microsatellite-primed polymerase chain reaction. J Mol Microbiol Biotechnol 2014;24:53-8.
Kondori N, Tehrani PA, Strömbeck L, Faergemann J. Comparison of dermatophyte PCR Kit with conventional methods for detection of dermatophytes in skin specimens. Mycopathologia 2013;176:237-41.
Dhib I, Fathallah A, Yaacoub A, Hadj Slama F, Said MB, Zemni R, et al
. Multiplex PCR assay for the detection of common dermatophyte nail infections. Mycoses 2014;57:19-26.
Brillowska-Dabrowska A, Michałek E, Saunte DM, Nielsen SS, Arendrup MC. PCR test for Microsporum canis identification. Med Mycol 2013;51:576-9.
Mehlig L, Garve C, Ritschel A, Zeiler A, Brabetz W, Weber C, et al
. Clinical evaluation of a novel commercial multiplex-based PCR diagnostic test for differential diagnosis of dermatomycoses. Mycoses 2014;57:27-34.
Uchida T, Makimura K, Ishihara K, Goto H, Tajiri Y, Okuma M, et al
. Comparative study of direct polymerase chain reaction, microscopic examination and culture-based morphological methods for detection and identifi cation of dermatophytes in nail and skin samples. J Dermatol 2009;36:202-8.
Bontems O, Hauser PM, Monod M. Evaluation of a polymerase chain reaction-restriction fragment length polymorphism assay for dermatophyte and nondermatophyte identification in onychomycosis. Br J Dermatol 2009;161:791-6.
[Table 1], [Table 2]
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||Major challenges and perspectives in the diagnostics and treatment of dermatophyte infections
| ||S. Gnat,D. Lagowski,A. Nowakiewicz |
| ||Journal of Applied Microbiology. 2020; |
|[Pubmed] | [DOI]|