Detection Of Dermatophytes Research Articles

Evaluation of Pan - Dermatophyte Nested PCR in Diagnosis of Onychomycosis in Comparison with Direct Microscopy and Culture

This work aimed to compare nested PCR using novel primers targeting the pan-dermatophyte-specific sequence of the chitin synthase 1 gene (CHS1) with KOH microscopy and culture isolation for diagnosis of clinically suspected onychomycosis. This study was conducted during the period from December, 2012 to October 2013. Forty patients attending Outpatient Dermatology and Andrology Clinic in Benha University Hospital. This study was done on forty patients 15 cases were female and the other 25 cases were males with abnormal nails .Their ages ranged from 22 to 77 years. As many as 19 patients were living in rural areas, while 21 patients came from urban areas. Nail scrapings were collected and examined using direct KOH microscopic examination, culture and PCR using double sets of primers. As regard direct microscopy by KOH examination; 33 (82.50%) cases were positive, while 7 (17.5%) were negative. Culture was positive only in 19(47.5%) of nail samples revealing different fungi. Dermatophytes were isolated from 15(37.5%) cases; most of them were T. mentagrophytes. And in 4 cases the only isolated non dermatophytic organism was Aspergillus Niger spp. (10.00%). Nested PCR was positive in 26 (65.00%) nail samples. Conclusion: It is concluded that nested PCR targeting the CHS1 gene may be considered the gold standard for detection of dermatophytes in patients with onychomycosis and can aid the clinician in initiating prompt and appropriate antifungal therapy.PCR is a very powerful tool for microbiology and clinical mycology. It can detect very small amounts of nucleic acids. This technique may also play an important role in large-scale studies and in the management of problematic cases of onychopathies.

Comparison of real-time PCR with conventional methods to detect dermatophytes in samples from patients with suspected dermatophytosis

A PCR detecting dermatophytes within a short turnaround time would significantly enhance the management of patients with suspected dermatophytosis. This study aimed at comparing the results of a real-time PCR assay with those of the conventional diagnostic (direct microscopy and culture) performed by a dermatologist working in a medical mycology laboratory for the detection of dermatophytes in nail and skin samples.A total of 112 specimens (54 nail and 58 skin) were collected from 52 patients with one to four suspected dermatophytosis lesions. The PCR diagnostic indices were calculated for either sample- or patient-based dermatophytosis diagnosis. The sample-based diagnostic efficacy yielded 79% sensitivity and 73% specificity. The patient-based diagnostic efficacy was higher with 100% sensitivity and 82% specificity. Interestingly, PCR yielded significantly (p<0.004) lesser false negative results and performed overall better (diagnostic odds ratio=24.0 vs. 5.5) in nail than in skin samples. In conclusion, this real-time PCR assay performance was consistent with those of the conventional methods in the hands of a skilled expert and particularly efficacious in diagnosing dermatophyte onychomycosis. This PCR is suited to high throughput batch processing; if used instead of direct microscopy, it could reduce hands-on time in the routine clinical laboratory workflow.

Comparison of Dermatophyte PCR Kit with Conventional Methods for Detection of Dermatophytes in Skin Specimens

The laboratory diagnosis of dermatophytosis is usually based on direct microscopic examination and culturing of clinical specimens. A commercial polymerase chain reaction kit (Dermatophyte PCR) has had favorable results when used for detection of dermatophytes and identification of Trichophyton rubrum in nail specimens. This study investigated the efficacy of the Dermatophyte PCR kit for detecting dermatophytosis in 191 hair or skin specimens from patients with suspected dermatophytosis. PCR was positive for 37% of samples, whereas 31 and 39% of the specimens were positive by culturing and direct microscopy, respectively. The sensitivity, specificity, positive predictive value, and negative predictive value for PCR analysis were 83, 84, 71, and 91%, respectively. The sensitivity of the PCR test was higher in specimens obtained from skin (88%) than in those obtained from hair (58%), while the specificity remained almost the same (84 and 86% for skin and hair, respectively). Our results show that the Dermatophyte PCR kit is a promising diagnostic tool for detection of dermatophytosis in skin samples, providing clinicians with a rapid diagnosis.

Multiplex PCR assay for the detection of common dermatophyte nail infections

Onychomycosis is one of the most prevalent dermatophytic diseases. Mycological methods used in the conventional diagnosis may not be optimal. Multiplex (MX) PCR was reported as a reliable alternative. Dermatophyte gene sequence records were used to design a MX PCR for detection and identification of dermatophytes in nail specimens. A MX PCR method based on the amplification of the chitin synthase 1 and internal transcribed spacer genes was developed. The study included 93 strains of dermatophytes and non-dermatophytic fungi, six dermatophytic reference strains and 201 nail specimens from patients with dermatophytic onyxis. DNA extraction directly from nail samples was carried out by using the QIAamp DNA extraction kit (Quiagen). A set of primers was designed and their specificity was assessed. MX PCR detected the causal agent in specimens from which Trichophyton rubrum and T. interdigitale grew in culture and also identified a dermatophyte species in an additional 32 specimens that were negative in microscopy and culture. None of the investigated non-dermatophytic strains was positive. Sensitivity of MX PCR was higher as compared to mycological examination (97% vs. 81.1%). MX PCR for direct detection of dermatophytes from nail samples yielded mixed flora in 32.8% of samples. MX PCR proved sensitive and adequate for the diagnosis of dermatophytic onychomycosis. It is much adapted to cases where culture is negative or contaminated by overgrowing moulds, which makes the identification of the causal agent problematic.

Fast and specific dermatophyte detection by automated DNA extraction and real-time PCR

The aim of this study was to develop and validate a rapid and sensitive real-time PCR method for detection of all known species of dermatophytes, including identification of Trichophyton rubrum and Trichophyton interdigitale. Fungal DNA was extracted directly from clinical samples by using a pre-lysis step, followed by automated DNA extraction on the MagNA Pure Compact. In total, 202 clinical samples were examined by both conventional culture and by the new PCR method. In 103 (51%) of the samples fungal nucleic acid was detected by PCR, while only 79 (39%) were found to be positive by culture. Out of 103 PCR-positive clinical samples, 94 (91%) were identified as T. rubrum and eight (8%) as T. interdigitale. This real-time PCR is far more sensitive and 2–4 weeks faster than conventional culture for detection of dermatophytes present in clinical samples.

Complementary role of a polymerase chain reaction test in the diagnosis of onychomycosis

The successful treatment of onychomycosis depends on accurate diagnosis. Conventional diagnostic methods, including direct microscopy and fungal culture, are non-specific, insensitive and time-consuming. Recently, PCR has shown promise in improving the diagnosis of onychomycosis. We aimed to evaluate a commercially available PCR kit for the in vitro detection of dermatophytes and specifically Trichophyton rubrum in nail specimens with suspected onychomycosis, and to compare the detection rates of PCR with conventional diagnostic methods. Nail specimens were prospectively collected from patients with clinically suspected onychomycosis. All nail specimens were positive on direct microscopic examination. PCR and fungal cultures were administered, and the detection rates of dermatophytes were compared. In all, 107 nail specimens were analysed. The fungal culture was positive in 57 (53%) specimens (38 dermatophytes and 19 non-dermatophytes). PCR was positive in 77 (72%) specimens (63 T. rubrum and 14 pan-dermatophyte). A total of 37 specimens (35%) were positive for both fungal culture and PCR. PCR detected dermatophytes in 39 specimens that were missed by the fungal culture, increasing the diagnosis of dermatophyte-positive specimens by 37%. Five dermatophyte-culture-positive specimens were negative for PCR. This study demonstrates that PCR increases the sensitivity of detection of dermatophytes in nail specimens. Despite its limitations, the use of PCR can complement direct microscopic examination and fungal cultures to aid clinicians in the diagnosis of suspected dermatophytic onychomycosis.

An improved molecular diagnostic assay for canine and feline dermatophytosis

The few studies attempting to specifically characterize dermatophytes from hair samples of dogs and cats using PCR-based methodology relied on sequence-based analysis of selected genetic markers. The aim of the present investigation was to establish and evaluate a PCR-based approach employing genetic markers of nuclear DNA for the specific detection of dermatophytes on such specimens. Using 183 hair samples, we directly compared the test results of our one-step and nested-PCR assays with those based on conventional microscopy and in vitro culture techniques (using the latter as the reference method). The one step-PCR was highly accurate (AUC > 90) for the testing of samples from dogs, but only moderately accurate (AUC = 78.6) for cats. A nested-PCR was accurate (AUC = 93.6) for samples from cats, and achieved higher specificity (94.1 and 94.4%) and sensitivity (100 and 94.9%) for samples from dogs and cats, respectively. In addition, the nested-PCR allowed the differentiation of Microsporum canis from Trichophyton interdigitale (zoophilic) and geophilic dermatophytes (i.e., Microsporum gypseum or Trichophyton terrestre), which was not possible using the one step-assay. The PCRs evaluated here provide practical tools for diagnostic applications to support clinicians in initiating prompt and targeted chemotherapy of dermatophytoses.

Neues zu Diagnostik und Therapie bei Mykosen der Haut

Recent observations indicate that Arthroderma benhamiae can cause bullous tinea, that onychomycosis increasingly occurs in children and that molds can cause tinea-like lesions. If a mycotic infection is suspected, the pathogen needs to be identified. The first genetic assays for the detection of dermatophytes have successfully been tested under routine conditions. Using appropriate techniques, genetic diagnosis is faster and more sensitive than a culture. Laboratory standards that would facilitate widespread implementation of genetic identification of dermatophytes have not yet been established. For the identification of yeasts, MALDI-TOF has already been established in many laboratories. This method is being refined for the diagnosis of hyphomycetes too. Newer antimycotics that are approved for certain systemic mycoses such as the triazoles voriconazole and posaconazole and the echinocandines caspofungin, micafungin und anidulafungin may be considered for dermatomycoses that cannot be treated by other therapies. Thermotherapy and photodynamic therapy are additional options in particularly difficult cases.

Evaluation of a newly‐developed immunochromatography strip test for diagnosing dermatophytosis

Traditionally, dermatophytosis, a common disease affecting millions of people world-wide, has been diagnosed by direct microscopy and fungal culture. The immunochromatography (ICG) strip test was recently developed. We compared the performance of the ICG strip test for the detection of dermatophytes in samples from human skin and nails with direct microscopy. The 160 samples, consisting of 88 skin and 72 nail specimens, were subjected to direct microscopy study using a 20% KOH solution and to examination with the ICG strip test. Of 160 samples, 18 were examined by fungal culture using Sabouraud dextrose agar medium. We found that the overall sensitivity and specificity of the ICG test were 83.5% and 66.7%; they were 82.1% and 76.2% for the 88 skin and 85.4% and 58.3% for the 72 nail specimens, respectively. Our findings indicate that the efficacy of the ICG test is comparable to direct microscopy for the detection of dermatophytes. Performance of the assay was easy, and results were available quickly. We suggest that it is an effective tool for dermatophytosis screening.

Evaluation of PCR for the diagnosis of dermatophytes in nail specimens from patients with suspected onychomycosis

Conventional methods for detecting fungi in nail specimens are either nonspecific (microscopy) or insensitive (culture). Recently, PCR has been used to improve sensitivity in detecting the causative fungi in nail specimens from patients with suspected onychomycosis. To compare the detection rates of PCR with those of microscopy (with potassium hydroxide; KOH) and culture for dermatophytes in nail specimens from patients with suspected onychomycosis. In total, 120 patients with clinically suspected onychomycosis were recruited, and using a topoisomerase II-based PCR, we compared the detection rate of dermatophytes for the three methods. KOH microscopy, culture and PCR respectively yielded positive rates of 35 (29.2%), 12 (10%) and 48 (40%), and negative rates of 85 (70.8%), 108 (90%) and 72 (60%). Two culture-positive specimens were not detected by PCR, but PCR picked up 38 specimens missed by culture. Of the 35 specimens that were microscopy-positive, 12 grew dermatophytes and 23 nondermatophytes. This study demonstrates that PCR has a higher positive and lower negative rate for detection of dermatophytes compared with KOH microscopy or culture. We suggest that PCR should be used as a complementary method for confirmation of clinically suspected dermatophytic onychomycosis.

Caracterização da microbiota por fungos filamentosos no tegumento hígido de bovinos de corte

O tegumento de bovinos pode albergar uma grande diversidade de fungos filamentosos, potencialmente capazes de causar dermatoses, incluindo fungos do grupo dos dermatófitos. O presente estudo teve por objetivos caracterizar a microbiota de fungos filamentosos do tegumento hígido de bovinos de corte, verificar a presença de dermatófitos como parte integrante da microbiota, assim como avaliar a ocorrência de dermatófitos no solo dos estabelecimentos estudados. Durante o período de um ano, 56 bovinos sadios de quatro propriedades da fronteira Oeste do RS foram submetidos a coletas mensais de pelos e raspado cutâneo. No mesmo período, foram obtidas amostras de solo para pesquisa de dermatófitos. As análises dos resultados indicaram uma microbiota de fungos filamentosos classificada em 30 gêneros, dos quais os mais frequentes foram (nesta ordem): Nigrospora, Fusarium, Curvularia, Alternaria, Epicoccum, Paecilomyces e Trichoderma. Nas amostras de pelame, obteve-se o isolamento de Trichophyton mentagrophytes (0,4%), Microsporum gypseum (0,3%) e Trichophyton verrucosum (0,1%). M. gypseum foi o dermatófito mais frequentemente isolado do solo. Os resultados obtidos evidenciaram que a microbiota fúngica do tegumento hígido de bovinos de corte comporta-se de maneira transitória e que bovinos sadios não atuam como portadores assintomáticos de T. verrucosum, sugerindo que esta espécie de dermatófito é não residente no tegumento dos animais.

Trapped in keratin; a comparison of dermatophyte detection in nail, skin and hair samples directly from clinical samples using culture and real-time PCR

Traditionally, laboratory detection and identification of dermatophytes consists of culture and microscopy which yields results within approximately 2–6 weeks. In 2007 our medical microbiological diagnostic laboratory implemented a molecular method for the detection of dermatophytes. A real-time PCR assay was developed which simultaneously detects and identifies the most prevalent dermatophytes directly in nail, skin and hair samples and has a turnaround time of less than two days. For 1437 clinical samples, received by our diagnostic laboratory, we compared the results obtained from both culture and real-time PCR. This study showed that real-time PCR significantly increased the detection rate of dermatophytes compared to culture. Furthermore, excellent concordance between culture and real-time PCR identification was achieved.

Molecular detection of dermatophytes and nondermatophytes in onychomycosis by nested polymerase chain reaction based on 28S ribosomal RNA gene sequences

Onychomycosis is often caused by dermatophytes, but the role of nondermatophytes is underestimated due to the difficulty of identifying them by conventional direct microscopy and culture. This study aims to detect nondermatophytes, as well as dermatophytes, in the nail samples of patients with onychomycosis using a polymerase chain reaction (PCR)-based culture-independent method. The nested PCR assay targeting the sequence of the 28S ribosomal RNA gene was used to amplify fungal DNAs from 50 microscopy-positive nail specimens. Newly designed primer sets for dermatophyte universal, Trichophyton rubrum, T. mentagrophytes, Aspergillus spp., Scopulariopsis brevicaulis, Fusarium solani, F. oxysporum, F. verticillioides, Candida albicans and C. tropicalis were used after confirmation of their specificity. Forty-seven cases (94%) were positive for fungal DNA, among which dermatophytes were detected in 39 cases (83.0%): T. rubrum in 35 cases (74.5%) and T. mentagrophytes in eight cases (17.0%). Surprisingly, nondermatophytes were detected in 18 cases (38.3%), both dermatophytes and nondermatophytes in 10 cases (21.3%) and nondermatophytes alone in eight cases (17.0%). Aspergillus spp. alone was observed in five cases (10.6%). This study indicates that most of the affected nail plates of patients with onychomycosis were positive for specific fungal DNAs, and suggests that nondermatophytes detected at high rates may be involved in the pathogenesis of onychomycosis.

Rapid detection of dermatophytes from skin and hair

BackgroundDermatophytes are a group of closely related keratinophilic fungi that can invade keratinized humans and animals tissues such as skin, hair and nails causing dermatophytosis. They are an important cause of superficial fungal infection.FindingsConventional methods like potassium hydroxide (KOH) microscopy and fungal culture lacks the ability to make an early and specific diagnosis. In this study we have evaluated nested Polymerase chain reaction (PCR) using primers targeting dermatophyte specific sequence of chitin synthase 1 (CHS1) gene and compared with conventional test. A total of 155 patients clinically suspected with dermatophytosis were included in the study. Of which 105 specimens were skin scrapings and 50 were hair. KOH microscopy, fungal culture and first round and nested PCR were done on clinical specimens, and results compared. Nested PCR for dermatophytes was positive in 83.8% specimens, followed by KOH microscopy (70%), first round PCR (50.8) and fungal culture (25.8).ConclusionResults indicate that nested PCR may be considered as gold standard for the diagnosis of dermatophytosis and can aid the clinician in initiating prompt and appropriate antifungal therapy.

Diagnosis of Trichophyton rubrum from Onychomycotic Nail Samples Using Polymerase Chain Reaction and Calcofluor White Microscopy

A high rate of false-negative dermatophyte detection is observed when the most common laboratory methods are used. These methods include microscopic observation of potassium hydroxide-digested nail clippings and culture methods using agar-based media supplemented with cycloheximide, chloramphenicol, and gentamicin to isolate dermatophytes. Microscopic detection methods that use calcofluor white staining or periodic acid-Schiff staining may also be substituted for and have previously been reported to be more sensitive than potassium hydroxide-digested nail clippings. Trichophyton rubrum infections were detected directly from nails in a double-round polymerase chain reaction assay that uses actin gene-based primers. This method was compared with detection of fungal hyphae by using calcofluor white fluorescence microscopy of nail samples collected from 83 patients with onychomycosis who were undergoing antifungal drug therapy. Twenty-six of 83 samples (31.3%) were found to be positive by calcofluor white fluorescence microscopy, and 21 of 83 samples (25.3%) yielded positive results for T rubrum when actin gene-based primers in a double-round polymerase chain reaction assay were used. When calcofluor white fluorescence microscopy and polymerase chain reaction assay were used, the combined detection was 46.9% compared with 31.3% when calcofluor microscopy and culture of nail samples on Sabouraud's dextrose agar supplemented with cycloheximide, chloramphenicol, and gentamicin were used. These results suggest that the use of a direct DNA protocol is an alternative method for detecting Trichophyton infections. When this protocol is used, the presence of T rubrum DNA is directly detected. However, the viability of the dermatophyte is not addressed, and further methods need to be developed for the detection of viable T rubrum directly from nail samples.

Five-Hour Diagnosis of Dermatophyte Nail Infections with Specific Detection ofTrichophyton rubrum

A rapid two-step DNA extraction method and a multiplex PCR for the detection of dermatophytes in general and Trichophyton rubrum specifically were developed and evaluated with DNA extracted from pure cultures and from clinically diseased nails. DNA from the following dermatophytes was used: Epidermophyton floccosum, Microsporum audouinii, Microsporum canis, Microsporum gypseum, Microsporum nanum, Trichophyton mentagrophytes, Trichophyton rubrum, Trichophyton schoenleinii, Trichophyton soudanense, Trichophyton terrestre, Trichophyton tonsurans, Trichophyton verrucosum, and Trichophyton violaceum. Human DNA and DNA from the following nondermatophyte fungi were included as controls: Alternaria, Aspergillus niger, Candida albicans, Candida glabrata, Candida krusei, Malassezia furfur, Saccharomyces cerevisiae, and Scopulariopsis brevicaulis. A total of 118 nail samples received for routine microscopy and culture for dermatophytes were subsequently tested by the two PCRs separately and in a multiplex format. Using DNA extracted from pure cultures and the pan-dermatophyte PCR, the T. rubrum-specific PCR sequentially and in a multiplex format correctly detected all dermatophytes and additionally correctly identified T. rubrum. Comparison of the traditional diagnostic evaluation (microscopy and culture) of nail samples with PCR on DNA directly extracted from the nails showed excellent agreement between PCR and microscopy, but the number of samples with dermatophyte species identification was increased considerably from 22.9% to 41.5%, mainly due to the identification of T. rubrum by PCR in microscopy-positive but culture-negative samples. In conclusion, this 5-hour diagnostic test was shown to increase not only the speed but also the sensitivity of investigation for nail dermatophytosis.

Rapid detection of Arthroderma vanbreuseghemii in rabbit skin specimens by PCR–RFLP

Three commercial rabbit farms independently reported suspected dermatophyte infections during 2004. Cultures confirmed that the infection was caused by the zoophilic Tricophyton mentagrophytes, while mating studies and sequencing of the internal transcribed spacer (ITS)1/4 polymerase chain reaction products, directly amplified from skin lesions and from pure culture isolates, established its Arthroderma vanbreuseghemii lineage. Subsequently, the corresponding DdeI restriction profiles of the ITS1/4 PCR products matched one of the two published T. mentagrophytes complex profiles. Sequence analysis of the published ITS sequences predicted distinct DdeI restriction sites for Arthroderma benhamiae and A. vanbreuseghemii, while all DdeI-generated restriction fragment length polymorphisms of the rabbit isolates were identical to those of A. vanbreuseghemii. The proposed procedure can be used for rapid dermatophyte detection and presumptive T. mentagrophytes identification.

Dermatomycosis: comparison of the performance of calcofluor and potassium hydroxide 30% for the direct examination of skin scrapings and nails

Dermatomycosis is a common problem in clinical practice. A definitive diagnosis should be made before initiation of antifungal therapy. Mycological diagnosis is usually based on direct microscopy using potassium hydroxide and fungal culture. The aim of our study was to compare the performance of potassium hydroxide 30% (KOH) with slight heating and staining with 0.01% calcofluor (Fluorescent brightener 28 ®) for the detection of fungi by direct microscopy. We evaluated prospectively 241 samples from patients suspected to have dermatomycosis (159 nail samples, 82 skin scrapings). Mycological culture was chosen as the reference method to assess the performance of each test. Out of the 241 samples, 152 mycological cultures were positive, of which 98 were classified as pathogenic fungi (86 dermatophytes, 11 non-dermatophyte molds, 1 Candida albicans). The sensitivity of direct microscopy was significantly higher with calcofluor than with KOH (respectively, 88% and 72%, P = 0.0116). Specificity was 93% with calcofluor and 88% with KOH ( P = NS). Calcofluor showed higher specificity on skin scraping than on nails samples (respectively, 100% and 89%, P = 0.0138) while KOH specificity did not differ as a function of the type of specimen (respectively, 92% and 86%). In conclusion, calcofluor is a more sensitive and specific technique than KOH for the microscopic detection of dermatophytes and non-dermatophyte pathogenic fungi in nails and skin scrapings. The results are easy to read by inexperienced staff.

Comparison of diagnostic methods in the evaluation of onychomycosis

Background Onychomycosis is a common problem seen in clinical practice. Given the differential diagnosis of dystrophic nails, it is helpful to obtain a definitive diagnosis of dermatophyte infection before the initiation of antifungal therapy. Potassium hydroxide (KOH) preparation and fungal culture, which are typically used in the diagnosis of these infections, often yield false-negative results. Recent reports have suggested that nail plate biopsy using periodic acid-Schiff (PAS) (Bx/PAS) stain may be a very sensitive technique for the diagnosis of onychomycosis. Objective The purpose of this study was to compare KOH preparation, culture, Bx/PAS stain, and calcofluor white (CW) stain in the diagnosis of onychomycosis and to determine their sensitivity and specificity. Methods We evaluated 105 patients with suspected onychomycosis using 4 diagnostic methods: KOH preparation, culture, Bx/PAS, and CW stain. CW stain binds to cellulose and chitin, and fluoresces when exposed to UV radiation. It is a highly sensitive and specific technique for the detection of dermatophytes. To determine the clinical usefulness and performance characteristics of each test, CW was chosen as the gold standard for statistical analysis. Results Of the patients, 93 had at least 1 of the 4 diagnostic methods positive for the presence of organisms. The following were calculated for each test: sensitivity; specificity; positive predictive value; and negative predictive value. The sensitivities of each of the techniques were as follows: KOH 80%; Bx/PAS 92%; and culture 59%. Both KOH and Bx/PAS methods were more sensitive than culture ( P = .00002). Bx/PAS was also more sensitive than KOH ( P = .03). The specificities were as follows: KOH 72%; Bx/PAS 72%; and culture 82%. The positive predictive value calculated for the different techniques were: KOH 88%; Bx/PAS 89.7%; and culture 90%. In terms of negative predictive value, the results were: KOH 58%; Bx/PAS 77%; and culture 43%. Conclusion Bx/PAS is the most sensitive method for the diagnosis of onychomycosis. It is also superior to the other methods in its negative predictive value. It is indicated if other methods are negative and clinical suspicion is high, and potentially is the single method of choice for the evaluation of onychomycosis.

Direct detection of dermatophytes in skin samples based on sequences of the chitin synthase 1 (CHS1) gene.

For the direct detection of dermatophytes in skin scrapings and hairs from animals, a primer pair specific to the chitin synthase 1 (CHS1) gene of dermatophytes was constructed. By PCR analysis with the primer pair, dermatophyte DNA could be diagnosed directly and rapidly in clinical skin samples.