Identification Of Dermatophytes Research Articles

Comparison of in vitro activities of newer triazoles and classic antifungal agents against dermatophyte species isolated from Iranian University Hospitals: a multi-central study

BackgroundDermatophytes have the ability to invade the keratin layer of humans and cause infections. The aims of this study were the accurate identification of dermatophytes by Polymerase Chain Reaction-Restriction Fragment Length Polymorphism method and sequencing and comparison between the in vitro activities of newer and established antifungal agents against them.MethodsClinical specimens of patients from five Iranian university laboratories were entered in this study. Samples were cultured on sabouraud dextrose agar medium. For molecular identification, extracted DNAs were amplified by the universal fungal primers ITS1 and ITS4, and digested with MvaI enzymes. The antifungal susceptibility test for each isolate to terbinafine, griseofulvin, caspofungin, fluconazole, itraconazole, luliconazole, and isavuconazole was performed, according to the microdilution CLSI M38-A2 and CLSI M61 standard methods.ResultsTwo hundred and seven fungi species similar to dermatophytes were isolated of which 198 (95.6%) were dermatophytes by molecular assay. The most commonly isolated were Trichophyton mentagrophytes (76/198), followed by Trichophyton interdigitale (57/198), Trichophyton rubrum (34/198), Trichophyton tonsurans (12/198), Microsporum canis (10/198), Trichophyton simii (3/198), Epidermophyton floccosum (3/198), Trichophyton violaceum (2/198), and Trichophyton benhamiae (1/198). The GM MIC and MIC90 values for all the isolates were as follows: terbinafine (0.091 and 1 μg/ml), griseofulvin (1.01 and 4 μg/ml), caspofungin (0.06 and 4 μg/ml), fluconazole (16.52 and 32 μg/ml), itraconazole (0.861 and 8 μg/ml), isavuconazole (0.074 and 2 μg/ml), and luliconazole (0.018 and 0.25 μg/ml).ConclusionTrichophyton mentagrophytes, Trichophyton interdigitale, and Trichophyton rubrum were the most common fungal species isolated from the patients. luliconazole, terbinafine, and isavuconazole in vitro were revealed to be the most effective antifungal agents against all dermatophyte isolates.

Isolation and Identification of Dermatophytes from the Skin of Cattle Presented for Slaughter at Zango Abattoir, Zaria, Kaduna State

Dermatophytes produce keratinases that dissolve the keratinous tissues of the skin and hairs; inflammation is caused by the host’s response to metabolic by products. The aim of this study was to isolate and identify dermatophytes from the skin of cattle presented for slaughter at Zango abattoir, Zaria, Nigeria. Samples were aseptically collected from twenty (20) cattle, cultured at room temperature for one to four weeks in Sabouraud’s Dextrose Agar (SDA). Growth from pure SDA cultures were sub-cultured on Potato dextrose agar and further incubated at room temperature for one to four weeks. Twelve animals were positive for dermatophytes either by microscopy, culture or both, thus producing an incidence of 60% with respect to the total number of the samples investigated (20). One (1) sample was positive by microscopy but eleven (11) were positive by both microscopy and culture. A large spectrum of dermatophytes consisting of eight species were recovered in the study. They were mostly zoophilic species which included M. canis, T. mentagrophytes, T. verrucosum, M. distortum and T. gallinae. Others were Geophilic specie (M. gypseum) and Anthropophilic species (T. soudanense and T. rubrum). M. canis was the most predominant species consisting of 41.7%. This study clearly demonstrated that cattle dermatophytoses in the study location was caused by different dermatophyte species with M. canis as the most prevalent. Some of the organisms are zoonotic, with public health relevance to animal handlers and butchers.

ITS-RFLP optimization for dermatophyte identification from clinical sources in Alagoas (Brazil) versus phenotypic methods.

Dermatophytoses are superficial mycoses, and the identification of their etiological agents is routinely performed by culture and microscopic features, which is time-consuming and relies on personnel expertise. Molecular approaches have been developed to provide faster and reliable results; therefore, this study aimed to identify dermatophytes isolated from Alagoas state patients, employing phenotypical and molecular methods. Clinical samples for morphological identification were collected from private and public laboratories and cultivated on Sabouraud dextrose agar. DNA extraction was followed by ITS amplicon analysis after restriction enzyme digestion DdeI (ITS-RFLP). Out of fourteen representative strains, ITS-RFLP with DdeI efficiently identified Microsporum canis, Nannizzia gypsea, and Trichophyton rubrum, while species of the complex T. tonsurans/T. mentagrophytes presented the same restriction pattern. After genotyping, 2 T. tonsurans and 1 Microsporum sp. strain were reclassified as T. rubrum. RFLP of ITS-region followed by DdeI digestion produced faster and relatively reliable results than classic methods; however, this method has not been as efficient for closely related dermatophytes cryptic species.

Evaluation of a Liquid Media MALDI-TOF MS Protocol for the Identification of Dermatophytes Isolated from Tinea capitis Infections.

One of the most common types of tinea is the superficial infection of the hair and scalp area known as tinea capitis. It is responsible for frequent outbreaks in nurseries and schools and represents a global health problem. Correct identification of the infection agent is essential in the determination of the infection source, epidemiological course, and treatment initiation. The conventional identification methods (direct exam, culture, DNA sequencing) are time-consuming, require experienced staff, are time-consuming, and the latter is expensive for routine identifications. Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) is gaining new ground for routine identification of filamentous fungi. The main advantages of MALDI-TOF MS are its rapid and accurate identification capability, relatively low cost, and easy integration into the laboratory routine. Its accuracy heavily depends on the quality of the reference spectra database. Identification of clinical isolates with MALDI-TOF MS protocol requires a sub-culturing step to ensure reliable identification. It can take days to weeks before fungal growth appears on solid medium. In this study, a unique MALDI-TOF MS protocol using liquid cultures of dermatophyte species was developed in order to shorten the turnaround time for the culture and identification of clinical isolates. Material and Method A standard MALDI-TOF MS protocol was adapted for liquid instead of solid cultures. Three different databases were tested. Results Using the liquid media MALDI-TOF MS protocol, a global rate of 62% correct identification (RCI) was obtained, compared with 87% for the protocol based on solid cultures. Trichophyton tonsurans was not correctly identified in all isolates using liquid cultures, with 88% of the isolates misidentified as Trichophyton interdigitale. The turnaround time for primary isolates for the solid and liquid protocols were respectively 11.7 and 11.6 days (no significant difference between both methods (p = 0.96)). Conclusions The newly designed liquid MALDI-TOF MS protocol did not lead to a significantly shorter turnaround time for the identification of dermatophytes isolated from tinea capitis infections. The turnaround time for the method with primary isolates was not significantly lower, and the rate of correct identification decreased remarkably, which emphasizes the need for a sub-culturing step. Using different database did not lead to improvement in turnaround time or rate of correct identification. This study highlights the importance of the medium and the reference database when performing MALDI-TOF MS.

Identification of Dermatophyte and Non-Dermatophyte Agents in Onychomycosis by PCR and DNA Sequencing-A Retrospective Comparison of Diagnostic Tools.

Rapid and reliable fungal identification is crucial to delineate infectious diseases, and to establish appropriate treatment for onychomycosis. Compared to conventional diagnostic methods, molecular techniques are faster and feature higher accuracy in fungal identification. However, in current clinical practice, molecular mycology is not widely available, and its practical applicability is still under discussion. This study summarizes the results of 16,094 consecutive nail specimens with clinical suspicion of onychomycosis. We performed PCR/sequencing on all primary nail specimens for which conventional mycological diagnostics remained inconclusive. In specimens with a positive direct microscopy but negative or contaminated culture, molecular mycology proved superior and specified a fungal agent in 65% (587/898). In 75% (443/587), the identified pathogen was a dermatophyte. Positive cultures for dermatophytes, yeasts and non-dermatophyte molds (NDMs) were concordant with primary-specimen-DNA PCR/sequencing in 83% (10/12), 34% (22/65) and 45% (76/169), respectively. Among NDMs, agreement was high for Fusarium spp. (32/40; 80%), but low for Penicillium spp. (5/25; 20%) and Alternaria spp. (1/20; 5%). This study underlines the improvement in diagnostic yield by fungal primary-specimen-DNA PCR/sequencing in the event of a negative or contaminated culture, as well as its significance for the diagnosis of dermatophyte and non-dermatophyte onychomycosis. Molecular mycology methods like PCR and DNA sequencing should complement conventional diagnostics in cases of equivocal findings, suspected NDM onychomycosis or treatment-resistant nail pathologies.

Molecular detection of dermatophytes isolated from tinea corporis infections in the Province of Wasit, Iraq

Background: The detection of fungal components in clinical specimens using direct microscopy in conjunction with culture-based full identification is the basis for dermatophyte identification. Physiological, macro-morphological, and micro-morphological parameters are used to identify colonies phenotypically. In recent years, it has been shown that molecular methods are useful for classifying dermatophyte species. Methods: Fifty samples that were taken from human cases of tinea corporis were examined mycologically. Phenotypic techniques were used to identify isolated dermatophytes. Internal transcribed spacer (ITS) PCR amplification was used for molecular identification. Using a specific primer, PCR was utilized to analyze the 18S rRNA gene in fungal isolates and the genes for virulence factors. Results: Out of Fifty samples with tinea corporis infections identified. Among them, which 3species were identified distribution to 26 cases Trichophyton mentagrophytes with a percentage of 52%, was the most frequently isolated dermatophyte 12 cases Trichophyton rubrum with a percentage 24% and 12 cases Microsporum canis with a percentage 24%. PCR product analysis of the 18S rRNA gene in dermatophytes isolates showed that all dermatophytes ssp. 100% were positive for 18S rRNA gene they obtained dermatophyte isolates (n=50) as follows: 26 Trichophyton mentagrophytes 12 Trichophyton rubrum, 12 Microsporum canis.

On the new classification of dermatophytes

According to the recent changes in the classification of the family Arthrodermataceae, it may already include 9 genera and 79 species. Dermatophytes associated with human and animal infections belong to the genera Trichophyton, Microsporum and Epidermophyton, whereas Arthroderma, Ctenomyces, Guarromyces, Lophophyton, Nannizzia and Paraphyton are mainly represented by geophilic species. Since morphological and physiological traits in fungi cannot provide reliable basis for classification, the modern system of dermatophytes was built on the basis of phylogenetic analysis of nucleotide sequences. The new dermatophyte classification employs the principle of one fungus, one name, according to which genetically similar perfect and imperfect forms belong to the same species.
 At the current state of genosystematics, the taxonomic identification of dermatophytes in most cases requires the use of molecular methods, in particular, DNA sequencing of the ITS region.
 In this review, we briefly outline the history of dermatophyte classification, summarize generic and species composition of the family and provide data on their ecology, accession numbers for reference sequences of ITS region, and references to major taxonomic publications.

Rapid and Visual RPA-Cas12a Fluorescence Assay for Accurate Detection of Dermatophytes in Cats and Dogs.

Dermatophytosis, an infectious disease caused by several fungi, can affect the hair, nails, and/or superficial layers of the skin and is of global significance. The most common dermatophytes in cats and dogs are Microsporum canis and Trichophyton mentagrophytes. Wood’s lamp examination, microscopic identification, and fungal culture are the conventional clinical diagnostic methods, while PCR (Polymerase Chain Reaction) and qPCR (Quantitative PCR) are playing an increasingly important role in the identification of dermatophytes. However, none of these methods could be applied to point-of-care testing (POCT). The recent development of the CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) based diagnostic platform promises a rapid, accurate, and portable diagnostic tool. In this paper, we present a Cas12a-fluorescence assay to detect and differentiate the main dermatophytes in clinical samples with high specificity and sensitivity. The Cas12a-based assay was performed with a combination of recombinase polymerase amplification (RPA). The results could be directly visualized by naked eyes under blue light, and all tested samples were consistent with fungal culture and sequencing results. Compared with traditional methods, the RPA-Cas12a-fluorescence assay requires less time (about 30 min) and less complicated equipment, and the visual changes can be clearly observed with naked eyes, which is suitable for on-site clinical diagnosis.

Agar-Based Disc Diffusion Assay for Susceptibility Testing of Dermatophytes in the Rajshahi Region

Background: Dermatophytosis is considered one of the most common public health problems in the world and is the most commonly diagnosed skin disease in Bangladesh. The prevalence and types of dermatophyte infections vary with climate conditions, age, lifestyle, and population migration patterns. Depending upon the anatomical site of the lesion, dermatophytes are classified into different varieties. Objective: To isolate dermatophytes and their antifungal susceptibility pattern by agar-based disc diffusion method in the Rajshahi region.
 Materials and Methods: Clinical samples (e.g., skin scrapings, nail clipping, and hair plucking) were collected under aseptic precautions. The identification of dermatophytes was performed through a microscopic examination using 10% KOH mount, mycological culture, and species identification by lactophenol cotton blue mount from culture. In addition, all dermatophytes isolates were subjected to antifungal susceptibility testing using the agar-based disc diffusion method.
 Results: Out of 171 samples, Trichophyton rubrum was the predominant dermatophyte species with 76(71.7%), followed by T.mentagrophyte were 15(14.2%), E. floccosum were 12(11.3%), and M. canis were 03(2.8%). Voriconazole and Itraconazole were more effective drugs. Griseofulvin was the least effective drug, followed by Fluconazole.
 Conclusion: Despite several treatment options being available for cutaneous fungal infections, Due to the increasing trend of antifungal drug resistance among dermatophytes, treatment should be based on antifungal sensitivity testing. The disc diffusion method is a simple and valuable method for the evaluation of antifungal susceptibility of dermatophytes.
 TAJ 2022; 35: No-1: 99-106

A Comparative Study on the Phenotypic Versus Molecular Identification of Clinical Dermatophytes

Dermatophytosis is the superficial infection of keratinized tissue like skin, hair, and nails, in humans and animals, by a group of closely related fungi known as dermatophytes. Phenotypic identification of dermatophytes, especially through classical methods can be difficult and uncertain at times, especially when differentiating species with overlapping characteristics. Alternative identification methods based on amplification and sequence analysis of the highly polymorphic internal transcribed spacer (ITS) sequences flanking the 5.8S ribosomal RNA gene has proven to be quite sensitive and reliable. The objective of our study was to compare the phenotypic and the ITS sequencing-based methods for the identification of clinically isolated dermatophyte specimens from Puducherry, India. A total of 13 clinical samples from 39 suspected cases were found positive for dermatophytes using KOH/DMSO preparations. Specimens were subsequently cultured in Sabouraud dextrose agar (SDA) supplemented with chloramphenicol, gentamicin, and cycloheximide. Dermatophytes were identified based on culture characteristics and microscopic examination in lactophenol cotton blue preparations. ITS sequencing was additionally performed after PCR amplification for species identification. Identification based on phenotype through microscopy and culture methods confirmed infections with Trichophyton mentagrophytes (n = 11), T. rubrum (n = 1), and Microsporum gypseum (n = 1). The strains were confirmed by ITS sequencing without any discrepancy with phenotypic identification. Identification of common dermatophytes based on phenotypic characteristics may be used as a reliable method of diagnosis where sophisticated methods like ITS sequencing and PCR are unavailable.

Apport de la spectrométrie de masse Maldi-TOF pour identifier les dermatophytes

AbstractMaldi-TOF mass spectrometry represents a major technical advance and an alternative to the relatively laborious and complex identification of dermatophytes by macroscopic and microscopic morphology, which requires highly skilled mycologists, an expertise that is becoming scarce in medical analysis laboratories. Provided that the dermatophyte has been successfully isolated in culture and that an adequate (i.e., comprehensive and in keeping with the current nomenclature) Maldi-TOF mass spectrometry reference spectra database is available, Maldi-TOF MS is relatively cheaper and offers a comparable accuracy to that of DNA sequencing for the identification of dermatophytes. The use of this new identification tool is likely to support to the ongoing dermatophytes taxonomic clarification. The taxonomic clarification will further contribute to a better understanding of the epidemiology of dermatophytes and the impact of the species involved on the outcomes of patients with dermatophytoses.

Dermatophyte Monitoring in an Iranian Training Dermatology Hospital

Introduction: The most common cutaneous fungal infections are caused by dermatophyte fungi such as Microsporum, Trichophyton, and Epidermophyton. In this study, the epidemiologic trends and the predominant organisms causing dermatophytosis in Urmia, Northwest Iran, were identified.Aims and objectives: To get better perception of dermatophyte distribution in Northwest Iran, the authors studied the identification of isolated dermatophytes from human specimens by using a fast and cheap molecular method: PCR-based restriction fragment length polymorphism (PCR-RFLP). The authors also aimed to use this method in for rapid and reliable identification of medically important and common dermatophytes at the level of species. Methods: The study samples were collected from clinically suspected cutaneous lesions. All the specimens were transported to Medical Mycology Center, Urmia Medical Sciences University (UMS), Iran. First of all, a conventional diagnosis was carried out, which included microscopic examination and culture of sabouraud dextrose agar medium with antibiotics: chloramphenicol and cycloheximide. All the dermatophyte isolates were then identified at the level of species by the molecular method of PCR-RFLP. Results: From the tested 357 clinical specimens, 30 dermatophytic isolates were identified. The percentage rate of dermatophyte species were Trichophyton mentagrophytes (36%), Microsporum canis (32%), Microsporum gypseum (16%), Trichophyton rubrum (4%), and Epidermophyton floccosum (12%). Conclusion: By using of PCR-RFLP, a fast and reliable identification of these species is possible. This molecular method provided an opportunity for dermatophyte identification at the species level.

Isolation, Identification and Speciation of Dermatophyte Infection in a Tertiary Care Hospital

Introduction: The common fungal infections seen in human are Dermatophytoses. They are capable to invade keratinized tissues. Mainly affect the skin, hair and nail, therefore, called as keratinophilic fungi. Dermatophytes falls under three Genus known as Trichophyton, Epidermophyton and Microsporum collectively called as dermatophytes. Unlike bacteria fungi are multicellular and are having different and specific morphology. They can be grown in the artificial media at room temperature and in human body temperature Objective: Isolation and identification of fungi will help to select the appropriate antifungal management of dermatophyte infection. Methodology: For isolation identification and speciation of dermatophytes the clinical specimens should be collected from skin, nail and hair which are obtained from patients attending the Dermatology department. Over a period of one and half year. A total no of 180 samples are collected from the patients. Samples are examined under direct microscopy in 10%, and 40% KOH. The morphology of the fungal hyphae is studied. Samples are also inoculated onto SDA and incubated at 25C and 37C for14 days. The colony characteristics and microscopic morphology in LPCB preparations are also examined. Based on the results the fungiare identified. Further speciation was carried out by using hair perforation test and Urease test. Results: All the 180 clinically suspected specimen of dermatophytes when examined results showed that most of the cases are seen between the age group of 21and 30 years. The predominant isolates belong to the genus Trichophyton (96.70%). Among the Trichophyton species mentagrophytes is the most common isolate (58.24%) T. rubrum is the next important species isolated. Conclusion: Early identification of the dermatophytes and timely given therapy will be of greater value in the prevention of fungal infection.

Isolation and Identification of Dermatophytes from Collegiate Runners

Competitive runners experience various risk factors that render them more susceptible to superficial cutaneous fungal infections, including the use of occlusive footwear, shared locker rooms, submission of feet to constant maceration, trauma, sweating, and having depressed immune function. The goal of this work was to assess the prevalence of athlete’s foot fungi in cross country runners at St. John Fisher College. Toe webs of 16 collegiate runners were sampled and volunteers surveyed about their shoe habits, foot hygiene, and average miles run per week. Lack of tinea pedis-causing fungi in asymptomatic cross- country runners shifted the study to investigate the identities of fungi morphologically similar to athlete’s foot and look for correlations with volunteers’ running habits and hygiene. Thirty-five distinct fungal cultures were isolated and compared to a known Trichophyton rubrum strain both microscopically and macroscopically. Four samples were preliminarily identified as tinea pedis-causing fungi and sequenced to confirm molecular identification. Fungal DNA was isolated, purified, and PCR amplified using primers for the internal transcribed spacer region, D1/D2 region of the 28S subunit, and β-Tubulin gene. Three of the four isolates were identified as Fusarium equiseti, a soil-borne plant pathogen with rare human pathogenicity reported. The fourth isolate was Beauveria bassiana, a common soil-borne pathogen that can infect immunocompromised individuals. Correct dermatophytic identification and understanding of the interplay between species is important to provide correct treatment, prevent spread among athletes and within facilities, and determine how opportunistic pathogens might play a role in people with immune suppressed function, which includes runners.

New Reference Genes for qRT-PCR Analysis as a Potential Target for Identification of Trichophyton verrucosum in Different Culture Conditions.

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.

Isolation and Identification of Dermatophytes from Environmental Specimens Comparing with Species Isolated from Clinical Specimens of Scalp Infection among Sudanese Basic School, Kosti, White Nile State, Sudan -2020

Background: Tinea capitis (TC) or scalp ringworm is common in pediatric population with reported rates of infection ranging from 4% to 15 % .T.rubrum is rarely reported in countries with a temperate climate . There is always hair loss with varying degrees of scaling and erythema [1-3]. Objectives: To identify the role of soil, plant & sewage in transmission of ringworm of scalp infection. This study was carried out on Kosti basic school students who suffering from ringworm of scalp (fungal infection) in White Nile state at Sudan in 2020. Methodology, Data Analyses and Results: Due to preservation of this fungal infection among school children in Kosti basic school students, a total of fifty specimens collected from different sources to determine the source of this infection in the area of study, twenty five students who suffering from ring worm of scalp and twenty five from soil, sewage, water and trees in the period between January – December -2020.The samples collected by scraping the scalp by surgical blade and removing the hair with needle and forceps from the peripheral lesion and gathered in filter paper and closed tightly,10% KOH was used to clarify and keratinized tissues. Trees samples were collected by washing the tree’s leaves and with all soil, sewage, water were collected into container. All samples were cultured on sabouroad dextrose agar medium for one week at room temperature. After growth, lactophenol cotton blue staining was used to identify depending on the colonial morphology under microscope and tolook for color, septate, aseptate hyphae, macro, micro conidia and spores. The results showed that there was 68% of isolates from soil, sewage, water and trees were matched to scalp isolates. The soil is significant one of these when Chi-square (X2) was used (P value = 0.027) that means, the source of infection among students may be due to soil transmission. Conclusion and Recommendation: Our results highlight the epidemiology of fungal infection of Kosti basic school students. Further studies are necessary to verify these findings considering the relatively high rate of fungal infection to cover all expected area with similar observation.

Isolation, Identification and Antifungal Susceptibility Testing Of Dermatophytes in Kimshrc, Bangalore

Isolation, Identification and Antifungal Susceptibility Testing Of Dermatophytes in Kimshrc, Bangalore

Identification and antifungal susceptibility testing of dermatophytes

Identification and antifungal susceptibility testing of dermatophytes

The qualitative accuracy of clinical dermatophytes via matrix-assisted laser desorption ionization-time of flight mass spectrometry: A meta-analysis.

Dermatophytes are an important part of superficial fungal infections, and accurate diagnosis is paramount for successful treatment. Recently, matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) has emerged as a powerful tool to identify clinical pathogens; its advantages are cost-effectiveness, rapid detection, and high accuracy. However, as the accurate identification of clinical dermatophytes via MALDI-TOF MS has still not been fully evaluated, we performed a meta-analysis for its systematic evaluation. Fifteen eligible studies were involved and showed high accuracy with an identification ratio of 0.96 (95% CI=0.92─1.01) and 0.91 (95% CI=0.86─0.96) at the genus and species levels, respectively. The results showed higher accuracy ratio of Vitek MS (91%) than MALDI Biotyper (85%). Dermatophytes such as Trichophyton interdigitale (0.99, 95% CI=0.97─1.02), T. mentagrophytes var interdigitale (1.00, 95% CI=0.98─1.02), and Microsporum canis (0.97, 95% CI=0.89─1.04) showed high accuracy in detected clinical dermatophytes. Moreover, a library with self-built database set up by laboratories showed higher accuracy than commercial database, and 15-day cultivation for dermatophytes showed highest accuracy considering culture time. High heterogeneity was observed and decreased only with the subgroup analysis of species. The subgroup analysis of mass spectrometry, library database, and culture time also exhibited high heterogeneity. In summary, our results showed that MALDI-TOF MS could be used for highly accurate detection of clinically pathogenic dermatophytes, which could be an alternative diagnostic method in addition to morphological and molecular methods.

Identification of Dermatophytes Isolated from Tinea Capitis Patients and Their in vitro Susceptibility to Terbinafine

Background: Tinea capitis is an infection caused by dermatophyte fungi of scalp hair follicles and the neighboring skin. Antifungal drugs as terbinafine that are used to treat dermatophytosis direct the ergosterol synthesis pathway. Aim of the work: The current study aimed to identify species and in vitro antifungal susceptibility profile of terbinafine on dermatophytes clinical isolates accompanied by sequencing of the highest minimal inhibitory concentration (MIC) isolates. Patients and methods: The present study is a descriptive cross-sectional study was conducted at Al-Azhar Hospital outpatient clinic, in the period from the 1st of July 2019 to the 15th of July 2020. Samples from 50 patients diagnosed clinically as tinea capitis were taken for microscopic examination by KOH and lactophenol cotton blue and culture on Sabouraud's dextrose agar followed by in vitro susceptibility testing to terbinafine then sequencing of the highest MIC isolates. Results: The isolated dermatophyte species were 16 (32%) isolates of M. canis and 23(46%) isolates of T.violaceum. The MIC varied from 0.003-.092 μg/ml for M.canis and from 0.005-0.116 μg/ml for T.violaceum. It was found in M. canis strain has two base variations with type strain from GenBank whereas T.violaceum strain has ten base variations in the two representative isolates with the highest MIC. Conclusion: T. violaceum was detected as the most common fun‌gal species followed by M. canis. The MIC results to terbinafine showed sensitivity to the antifungal agents. By comparing the M. canis and T. violaceum isolates with type strain on GenBank, some base-pair substitutions were found.