In vitro antifungal susceptibility of the dermatophytes: a single center study from Eastern Black Sea Region of Turkey.

OBJECTIVE: A large number of patients applying to the dermatology clinics are affected by fungal diseases, and a significant portion of which are superficial fungal infections. Dermatophyte infections are a notable public health concern and frequently encountered in clinical practice. Dermatophytosis not only compromises the quality of life but also predisposes individuals to various comorbidities due to its role as a gateway for secondary bacterial agents. This study aims to determine the species distribution of dermatophytes prevalent and assess their susceptibility to antifungal drugs. PATIENTS AND METHODS: Skin, nail, and hair samples were obtained from patients with a clinical diagnosis of dermatophytosis. Samples were all cultured to isolate and identify the species. In vitro liquid microdilution tests were conducted to assess the susceptibility of the isolated strains against terbinafine, fluconazole, griseofulvin, and butenafine. RESULTS: A total of 353 samples were obtained from the hair, skin, and nail lesions of 326 patients. Dermatophyte was isolated in 71 of the samples (20.1%). The cultured dermatophyte subtypes included Trichophyton rubrum (13.8% in 49 samples), Microsporum audouini (5.7% in 20 samples), and Trichophyton mentagrophytes (0.6% in 2 samples). Antifungal susceptibility testing revealed that terbinafine was the most effective antifungal drug against all dermatophyte species, while fluconazole exhibited the highest resistance. CONCLUSIONS: The most common dermatophytosis agent in our region is T. rubrum. The least antifungal resistance was found against terbinafine. Conducting antifungal susceptibility tests is crucial for selecting effective treatment regimens and early detection of resistance development.

Dermatophytes and skin dermatophytoses in Southeast Asia-First epidemiological survey from Cambodia.

BACKGROUND: Dermatomycoses count to the most frequent dermatoses in Cambodia. OBJECTIVES: The aim of this survey was to investigate the occurrence of dermatophytes in this Southeast Asian country. METHODS: From June 2017 to July 2018, skin scrapings were taken from 67 patients with superficial dermatophytosis for mycological diagnostics. Identification of dermatophytes was confirmed by sequencing of the 'internal transcribed spacer'-(ITS) region of the rDNA, and the gene of the Translation Elongation Factor (TEF)-1α. RESULTS: Patients were suffering from tinea corporis and tinea inguinalis/cruris 42/67 (63%), tinea capitis/faciei 14/67 (21%), tinea corporis/capitis/faciei 6/67 (9%), tinea manuum/pedis 2/67 (3%), tinea pedis 2/67 (3%) and tinea manuum 1/67 (1%). Both, by culture and/or PCR, a dermatophyte was detected in 52 (78%) out of 67 samples. Culture positive were 42 (81%) of 52, PCR positive were 50 (96%). The following dermatophytes were found: Trichophyton (T.) rubrum, 36/52 strains (69%, 29 by culture), T. mentagrophytes/T. interdigitale (TM/TI) 9/52 (17%, six by culture) and Microsporum (M.) canis 5/52 strains (10%, by culture). One strain of Nannizzia (N.) incurvata 1/52 (2%) and N. nana 1/52 (2%) was isolated. Based on sequencing, we demonstrated that two T. mentagrophytes strains out of the nine TM/TI represented the new ITS genotype XXV Cambodia. We found one T. mentagrophytes strain genotype VIII (now, reclassified as T. indotineae). This isolate was terbinafine resistant, and it exhibited the amino acid substitution Phe397Leu in the squalene epoxidase. Three strains of T. interdigitale genotype II* were isolated. CONCLUSION: This is the first survey on epidemiology of dermatophytes in Cambodia. Currently, T. rubrum represents the most frequent species in Cambodia. One Indian strain genotype VIII T. mentagrophytes was found. A highlight was the first description of the new T. mentagrophytes genotype XXV Cambodia.

Responses of keratinocytes to Trichophyton mentagrophyte infection based on whole transcriptome analysis.

BACKGROUND: Dermatophytosis is an intractable superficial mycosis in humans and animals mainly caused by Trichophyton mentagrophytes (T. mentagrophytes), with a global prevalence of about 20%. Keratinocytes are the most abundant participants in skin immunity, and they also play a role in the first-line defence against T. mentagrophytes. However, no studies of keratinocyte responses against T. mentagrophytes infection based on the whole transcriptome have been reported. OBJECTIVES: Here, we systematically analysed changes in keratinocytes infected with T. mentagrophytes using whole transcriptome sequencing technology. METHODS: The phenotypic changes in keratinocytes after infection with 1 × 105 conidia/mL T. mentagrophytes were observed by light microscopy, scanning electron microscopy, transmission electron microscopy and terminal deoxynucleotidyl transferase dUTP nick end labeling. RNA-sequencing (RNA-seq), small RNA-seq technology and related bioinformatics methods were used to systematically analyse the whole transcriptome changes in keratinocytes upon T. mentagrophytes stimulation. RESULTS: We found that T. mentagrophytes infection caused morphological changes, membrane damage, the formation of irregular organelles and keratinocyte apoptosis. A total of 204 differentially expressed (DE) circular RNAs (circRNAs), 868 DE long noncoding RNAs (lncRNAs), 2973 DE mRNAs and 209 DE micro RNAs (miRNAs) were identified between noninfected and T. mentagrophytes-infected keratinocytes. The expression level of selected RNAs was validated by quantitative real-time polymerase chain reaction (qRT-PCR). Functional enrichment analysis revealed that the parental genes of DE circRNAs were related to cell response, cell death and establishment of the skin barrier. Genes targeted by miRNA were involved in regulating the initiation of the immune response. Based on the expression level of circRNAs, lncRNAs, mRNAs and miRNAs, circRNA-miRNA-mRNA competing endogenous (ceRNA) networks comprised of 159 DE miRNAs, 141 DE circRNAs and 2307 DE mRNAs, and lncRNA-miRNA-mRNA ceRNA networks comprised of 790 DE lncRNAs, 190 DE miRNAs and 2663 DE mRNAs were constructed. The reliability of two selected ceRNA networks was verified using qRT-PCR. Further functional enrichment analysis revealed that the DE mRNAs interacting with circRNAs and lncRNAs in the ceRNA network mainly participated in fungal recognition, inflammation, the innate immune response and the death of keratinocytes. CONCLUSIONS: Our findings might provide new evidence on the pathogenesis of T. mentagrophytes-induced dermatophytosis, which is essential for identifying new therapeutic targets for dermatophytosis treatment.

Antifungal activity of 3,3'-dimethoxycurcumin (DMC) against dermatophytes and Candida species.

Dermatomycosis is an infection with global impacts caused especially by dermatophytes and Candida species. Current antifungal therapies involve drugs that face fungal resistance barriers. This clinical context emphasizes the need to discover new antifungal agents. Herein, the antifungal potential of 10 curcumin analogs was evaluated against four Candida and four dermatophyte species. The most active compound, 3,3'-dimethoxycurcumin, exhibited minimum inhibitory concentration values ranging from 1.9‒62.5 to 15.6‒62.5 µg ml-1 against dermatophytes and Candida species, respectively. According to the checkerboard method, the association between DMC and terbinafine demonstrated a synergistic effect against Trichophyton mentagrophytes and Epidermophyton floccosum. Ergosterol binding test indicated DMC forms a complex with ergosterol of Candida albicans, C. krusei, and C. tropicalis. However, results from the sorbitol protection assay indicated that DMC had no effect on the cell walls of Candida species. The in vivo toxicity, using Galleria mellonella larvae, indicated no toxic effect of DMC. Altogether, curcumin analog DMC was a promising antifungal agent with a promising ability to act against Candida and dermatophyte species.

Resistance Profile, Terbinafine Resistance Screening and MALDI-TOF MS Identification of the Emerging Pathogen Trichophyton indotineae.

The emerging pathogen Trichophyton indotineae, often resistant to terbinafine (TRB), is known to cause severe dermatophytoses such as tinea corporis and tinea cruris. In order to achieve successful treatment for these infections, insight in the resistance profile of T. indotineae strains and rapid, reliable identification is necessary. In this research, a screening medium was tested on T. indotineae strains (n = 20) as an indication tool of TRB resistance. The obtained results were confirmed by antifungal susceptibility testing (AST) for TRB following the in vitro broth microdilution reference method. Additionally, AST was performed for eight other antifungal drugs: fluconazole, itraconazole, voriconazole, ketoconazole, griseofulvin, ciclopirox olamine, naftifine and amorolfine. Forty-five percent of the strains were confirmed to be resistant to terbinafine. The TRB resistant strains showed elevated minimal inhibitory concentration values for naftifine and amorolfine as well. DNA sequencing of the squalene epoxidase-encoding gene showed that TRB resistance was a consequence of missense point mutations in this gene, which led to amino acid substitutions F397L or L393F. MALDI-TOF MS was used as a quick, accurate identification tool for T. indotineae, as it can be challenging to distinguish it from closely related species such as Trichophyton mentagrophytes or Trichophyton interdigitale using morphological characteristics. While MALDI-TOF MS could reliably identify ≥ 95% of the T. indotineae strains (depending on the spectral library), it could not be used to successfully distinguish TRB susceptible from TRB resistant strains.

Antifungal activity and potential mechanism of action of Huangqin decoction against Trichophyton rubrum.

Introduction. Trichophyton rubrum is a major causative agent of superficial dermatomycoses such as onychomycosis and tinea pedis. Huangqin decoction (HQD), as a classical traditional Chinese medicine formula, was found to inhibit the growth of common clinical dermatophytes such as T. rubrum in our previous drug susceptibility experiments.Hypothesis/Gap Statement. The antifungal activity and potential mechanism of HQD against T. rubrum have not yet been investigated.Aim. The aim of this study was to investigate the antifungal activity and explore the potential mechanism of action of HQD against T. rubrum.Methodology. The present study was performed to evaluate the antifungal activity of HQD against T. rubrum by determination of minimal inhibitory concentrations (MICs), minimal fungicidal concentrations (MFCs), mycelial growth, biomass, spore germination and structural damage, and explore its preliminary anti-dermatophyte mechanisms by sorbitol and ergosterol assay, HPLC-based ergosterol test, enzyme-linked immunosorbent assay and mitochondrial enzyme activity test.Results. HQD was able to inhibit the growth of T. rubrum significantly, with an MIC of 3.125 mg ml-1 and an MFC of 12.5 mg ml-1. It also significantly inhibited the hyphal growth, conidia germination and biomass growth of T. rubrum in a dose-dependent manner, and induced structural damage in different degrees for T. rubrum cells. HQD showed no effect on cell wall integrity, but was able to damage the cell membrane of T. rubrum by interfering with ergosterol biosynthesis, involving the reduction of squalene epoxidase (SE) and sterol 14α-demethylase P450 (CYP51) activities, and also affect the malate dehydrogenase (MDH), succinate dehydrogenase (SDH) and ATPase activities of mitochondria.Conclusion. These results revealed that HQD had significant anti-dermatophyte activity, which was associated with destroying the cell membrane and affecting the enzyme activities of mitochondria.

Terbinafine resistance in Trichophyton mentagrophytes and Trichophyton rubrum in the Czech Republic: A prospective multicentric study.

BACKGROUND: Terbinafine, an allylamine antifungal, is crucial for treating dermatophytosis by inhibiting squalene epoxidase (SQLE) in the ergosterol biosynthetic pathway. However, resistance is emerging, particularly in India and Southeast Asia, but reports of resistance spread worldwide. Despite this, comprehensive studies on terbinafine resistance in Trichophyton are still limited. OBJECTIVES: This research aimed to determine the prevalence of terbinafine resistance in the Czech Republic, with a focus on Trichophyton rubrum and Trichophyton mentagrophytes, and investigate the underlying molecular mechanisms. PATIENTS/METHODS: A total of 514 clinical strains of T. rubrum and 240 T. mentagrophytes collected from four Czech clinical institutions were screened for terbinafine resistance. Molecular investigations included DNA sequencing, specifically the ITS rDNA region and SQLE gene, as well as antifungal susceptibility testing following EUCAST guidelines. RESULTS: While no resistance was observed in T. rubrum, 2.5% of T. mentagrophytes strains exhibited resistance, marked by the F397L mutation in SQLE. Notably, resistance surged from 1.2% in 2019 to 9.3% in 2020 but reverted to 0% in 2021. All resistant strains were identified as T. mentagrophytes var. indotineae. Resistant strains exhibited high MICs for terbinafine (≥4 mg L-1 ) but low MICs to the other seven antifungals tested except for fluconazole. CONCLUSIONS: This study highlights the emergence of terbinafine-resistant T. mentagrophytes strains in the Czech Republic, with the F397L mutation being pivotal. Due to the relatively low resistance level, the current guidelines for dermatomycosis treatment in the Czech Republic remain effective, but ongoing surveillance is essential for timely adaptations if resistance patterns change.

Riparin II-type benzamides as novel antibiofilm agents against dermatophytes: chemical synthesis, in vitro, ex vivo and in silico evaluation.

BACKGROUND: The ability of dermatophytes to develop biofilms in host tissues confers physical and biochemical resistance to antifungal drugs. Therefore, research to find new compounds against dermatophyte biofilm is crucial. OBJECTIVES: To evaluate the antifungal activity of riparin II (RIP2), nor-riparin II (NOR2) and dinor-riparin II (DINOR2) against Trichophyton rubrum, Microsporum canis and Nannizzia gypsea strains. METHODS: Initially, we determined the minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of benzamides. We evaluated the inhibitory effects on the development of dermatophyte biofilms using in vitro and ex vivo models. Finally, we built three-dimensional models of the sulphite pump Ssu1 to investigate the interactions with the benzamides by molecular docking. RESULTS: RIP2 showed a broad spectrum of activity against T. rubrum, M. canis and N. gypsea, whereas NOR2 and DINOR2 were more selective. Furthermore, the shortening of the carbon chain from RIP2 benzamide to NOR2 and DINOR2 homologs caused a decrease in the MIC values. The benzamides reduced biofilm production and viability in vitro (P < 0.05) at MIC. This result was similar ex vivo in human nail fragments tests, but NOR2 and DINOR2 showed significant results at 2xMIC (P < 0.05). We constructed a model of the Ssu1 protein for each dermatophyte with high similarity. Molecular docking showed that the benzamides obtained higher binding energy values than ciclopirox. CONCLUSIONS: Our study shows the antibiofilm potential for riparin II-type benzamides as new drugs targeting dermatophytes by inhibiting the Ssu1 protein.

Identification of primary metabolites in fungal species of Trichophyton mentagrophyte and Trichophyton rubrum by NMR spectroscopy.

BACKGROUND: Superficial mycoses are fungal infections limited to the outermost layers of the skin and its appendages. The chief causative agents of these mycoses are dermatophytes and yeasts. The diagnosis of dermatophytosis can be made by direct mycological examination with potassium hydroxide (10%-30%) of biological material obtained from patients with suspected mycosis, providing results more rapid than fungal cultures, which may take days or weeks. This information, together with clinical history and laboratory diagnosis, ensures that the appropriate treatment is initiated promptly. However, false negative results are obtained in 5%-15%, by conventional methods of diagnosis of dermatophytosis. OBJECTIVES: To study the metabolic profiles of the commonly occurring dermatophytes by NMR spectroscopy. PATIENTS/MATERIALS: We have used 1D and 2D Nuclear Magnetic Resonance (NMR) experiments along with Human Metabolome Database (HMDB) and Chenomx database search for identification of primary metabolites in the methanol extract of two fungal species: Trichophyton mentagrophyte (T. mentagrophyte) and Trichophyton rubrum (T. rubrum). Both standard strains and representative number of clinical isolates of these two species were investigated. Further, metabolic profiles obtained were analysed using multivariate analysis. RESULTS: We have identified 23 metabolites in the T. mentagrophyte and another 23 metabolites in T. rubrum. Many important metabolites like trehalose, proline, mannitol, acetate, GABA and several other amino acids were detected, which provide the necessary components for fungal growth and metabolism. Altered metabolites were defined between Trichophyton mentagrophyte and T. rubrum strains. CONCLUSION: We have detected many metabolites in the two fungal species T. mentagrophyte and T. rubrum by using NMR spectroscopy. NMR spectroscopy provides a holistic snapshot of the metabolome of an organism. Key metabolic differences were identified between the two fungal strains. We need to perform more studies on metabolite profiling of the samples from these species for their rapid diagnosis and prompt treatment.

Whole genome characterization of Trichophyton indotineae isolated in Singapore.

Complete genome sequences from two Trichophyton indotineae isolates were obtained from a 23-year-old male presenting with tinea cruris after an overseas recreational water exposure and from a 53-year-old female patient with unknown travel history. Analysis of the squalene epoxidase gene and the cyp51 gene family showed an absence of mutations, correlating with phenotypic drug susceptibility. The Single Nucleotide Polymorphisms (SNPs) distance between both isolates was 92. Within the T. indotineae cluster, SNPs ranged from 7 to 182, suggesting a high genetic relatedness with other South Asian isolates. This study suggests that the prevalence of T. indotineae is under-reported and more widespread than previously thought.

Trichophyton indotineae, is a fungus causing difficult to treat ringworm infections. Two isolates were sequenced and their relationship and to other isolates was characterized. We also studied the genes responsible for first-line antifungal treatment.

Studies on the in vitro mechanism and in vivo therapeutic effect of the antimicrobial peptide ACP5 against Trichophyton mentagrophytes.

Trichophyton mentagrophytes is a zoophilic dermatophyte that can cause dermatophytosis in humans and animals. Antimicrobial peptides (AMPs) are considered as a promising agent to overcome the drug-resistance of T. mentagrophytes. Our findings suggest that cationic antimicrobial peptide (ACP5) not only possesses stronger activity against T. mentagrophytes than fluconazole, but also shows lower toxicity to L929 mouse fibroblast cells than terbinafine. Notably, its resistance development rate after resistance induction was lower than terbinafine. The present study aimed to evaluate the fungicidal mechanism of ACP5 in vitro and its potential to treat dermatophyte infections in vivo. ACP5 at 1 ×MIC completely inhibited T. mentagrophytes spore germination in vitro. ACP5 severely disrupts the mycelial morphology, leading to mycelial rupture. Mechanistically, ACP5 induces excessive ROS production, damaging the integrity of the cell membrane and decreasing the mitochondrial membrane potential, causing irreversible damage in T. mentagrophytes. Furthermore, 1% ACP5 showed similar efficacy to the commercially available drug 1% terbinafine in a guinea pig dermatophytosis model, and the complete eradication of T. mentagrophytes from the skin by ACP5 was verified by tissue section observation. These results indicate that ACP5 is a promising candidate for the development of new agent to combat dermatophyte resistance.

Artemisia argyi extract subfraction exerts an antifungal effect against dermatophytes by disrupting mitochondrial morphology and function.

Artemisia argyi (A. argyi), a plant with a longstanding history as a raw material for traditional medicine and functional diets in Asia, has been used traditionally to bathe and soak feet for its disinfectant and itch-relieving properties. Despite its widespread use, scientific evidence validating the antifungal efficacy of A. argyi water extract (AAWE) against dermatophytes, particularly Trichophyton rubrum, Trichophyton mentagrophytes, and Microsporum gypseum, remains limited. This study aimed to substantiate the scientific basis of the folkloric use of A. argyi by evaluating the antifungal effects and the underlying molecular mechanisms of its active subfraction against dermatophytes. The results indicated that AAWE exhibited excellent antifungal effects against the three aforementioned dermatophyte species. The subfraction AAWE6, isolated using D101 macroporous resin, emerged as the most potent subfraction. The minimum inhibitory concentrations (MICs) of AAWE6 against T. rubrum, M. gypseum, and T. mentagrophytes were 312.5, 312.5, and 625 µg·mL-1, respectively. Transmission electron microscopy (TEM) results and assays of enzymes linked to cell wall integrity and cell membrane function indicated that AAWE6 could penetrate the external protective barrier of T. rubrum, creating breaches ("small holes"), and disrupt the internal mitochondrial structure ("granary"). Furthermore, transcriptome data, quantitative real-time PCR (RT-qPCR), and biochemical assays corroborated the severe disruption of mitochondrial function, evidenced by inhibited tricarboxylic acid (TCA) cycle and energy metabolism. Additionally, chemical characterization and molecular docking analyses identified flavonoids, primarily eupatilin (131.16 ± 4.52 mg·g-1) and jaceosidin (4.17 ± 0.18 mg·g-1), as the active components of AAWE6. In conclusion, the subfraction AAWE6 from A. argyi exerts antifungal effects against dermatophytes by disrupting mitochondrial morphology and function. This research validates the traditional use of A. argyi and provides scientific support for its anti-dermatophytic applications, as recognized in the Chinese patent (No. ZL202111161301.9).

[Trichophyton mentagrophytes genotype VII increasingly causes anogenital infections]. / Trichophyton mentagrophytes Genotyp VII als zunehmender Auslöser anogenitaler Infektionen.

In the course of globalization, migration and global warming, we are increasingly confronted with pathogens that do not occur naturally in our latitudes or appear in a different form. We know keratinophilic dermatophytes as the cause of tinea pedis, onychomycosis and also tinea corporis and capitis. Transmission usually occurs via domestic or farm animals and via autoinoculation. In recent years dermatophytes have gained additional importance as a possible sexually transmitted disease between immunocompetent persons. For the first time, dermatophytosis was described as a sexually transmitted infection in travelers who developed pronounced pubogenital or anogenital tinea after travelling in Southeast Asia, including Thailand, mostly after intensive sexual contact. Molecular and cultural analyses have identified Trichophyton (T.) mentagrophytes ITS (internal transcribed spacer) genotype VII as the main pathogen. Although this dermatophyte genotypically belongs to the zoophilic complex, direct (sexual) and occasionally indirect human-to-human contact with infected persons is suspected to be the current route of transmission. The infection can lead to inflammatory and purulent dermatophytosis, causing a high level of suffering. In this respect, a rapid and reliable diagnosis is essential in order to be able to initiate targeted treatment. The discovery of infection pathways and the awareness of the need to take rare diseases into account in our everyday lives will increasingly accompany us over the next few years and present us with new challenges, particularly in terms of prevention and treatment.

Effectiveness and safety of oral terbinafine for dermatophyte distal subungual onychomycosis.

INTRODUCTION: Terbinafine has been a cornerstone in dermatophyte infection treatment. Despite its global efficacy, the emergence of terbinafine resistance raises concerns, requiring ongoing vigilance. AREAS COVERED: This paper focuses on evaluating the efficacy and safety of terbinafine in treating dermatophyte toenail infections. Continuous and pulse therapies, with a 24-week continuous regimen and a higher dosage of 500 mg/day have demonstrated superior efficacy to the FDA approved regimen of 250 mg/day x 12 weeks. Pulse therapies, though showing comparable effectiveness, present debates with regards to their efficacy as conflicting findings have been reported. Safety concerns encompass hepatotoxicity, gastrointestinal, cutaneous, neurologic, hematologic and immune adverse-effects, and possible drug interactions, suggesting the need for ongoing monitoring. EXPERT OPINION: Terbinafine efficacy depends on dosage, duration, and resistance patterns. Continuous therapy for 24 weeks and a dosage of 500 mg/day may enhance outcomes, but safety considerations and resistance necessitate individualized approaches. Alternatives, including topical agents and alternative antifungals, are to be considered for resistant cases. Understanding the interplay between treatment parameters, adverse effects, and resistance mechanisms is critical for optimizing therapeutic efficacy while mitigating resistance risks. Patient education and adherence are vital for early detection and management of adverse effects and resistance, contributing to tailored and effective treatments.

Molecular Verification of Trichophyton in the Brazilian URM Culture Collection.

Trichophyton species cause dermatophytosis in humans, with a high, worldwide frequency of reports and important public health relevance. We evaluated 61 Trichophyton strains from different sources deposited in the University Recife Mycology (URM) culture collection of the Universidade Federal de Pernambuco, Brazil. Strains were phenotypically identified and confirmed by sequencing Internal Transcribed Spacers rDNA and partial beta-tubulin 2-exon. Additionally, we evaluated their susceptibility to terbinafine and itraconazole. Physiological analyses included urease activity and growth in casein medium. Phenotypic methods allowed the reliable identification of T. rubrum only, whereas, for other species, molecular methods were mandatory. All Trichophyton species exhibited susceptibility profiles to itraconazole (0.04-5.33 µg/mL) and terbinafine (0.17-3.33 µg/mL). Our analyses revealed a heterogeneous distribution of T. mentagrophytes, which does not support the current distribution within the species complex of T. mentagrophytes and its genotypes.

Expression Profiles of Protease in Onychomycosis-Related Pathogenic Trichophyton rubrum and Tinea Capitis-Related Pathogenic Trichophyton violaceum.

The two fungal species Trichophyton rubrum and Trichophyton violaceum are common pathogens on human, infecting keratinized tissue of the outer body parts. Both species are belonging to the "Trichophyton rubrum complex" and share very high similarity in the genome. Secreted proteinases, key factors for keratin degradation, are nearly identical. Contrary, the ecological niches are differing. Trichophyton rubrum preferably infects skin and nails, whereas T. violaceum preferably infects the scalp. We postulate, that differences in the protease expression contribute to differences in ecological preferences. We analyzed the expression profiles of all 22 endoprotease genes, 12 subtilisins (S8A), 5 deuterolysins (M35) and 5 fungalysins (M36), for both species. To compare the influence of the keratin source, we designed experiments with human nail keratin, sheep wool keratin and keratin free cultivation media. Samples were taken at 12 h, 24 h, 48 h and 96 h post incubation in keratin medium. The expression of the proteases is higher in wool-keratin medium compared to human nail medium, with the exception of MEP4 and SUB6. Expression in the keratin-free medium is lowest. The expression profiles of the two species are remarkable different. The expression of MEP1, MEP3, SUB5, SUB11 and SUB12 are higher in T. rubrum compared to T. violaceum. MEP2, NpIIc, NpIIe, SUB1, SUB3, SUB4, SUB7 and SUB8 are higher expressed in T. violaceum compared to T. rubrum. The differences of the protease expression in the two species may expalin the differences in the ecological niches. Further analysis are necessary to verify the hypothesis.Please check and conform the edit made in title.Here I thinke the species of strains shouldnt be capital， and the right expression should be,  "Expression Profiles of Protease in Onychomycosis-Related Pathogenic Trichophyton rubrum and Tinea Capitis-Related Pathogenic Trichophyton violaceum"Author names: Please confirm if the author names are presented accurately and in the correct se-quence (given name, middle name/initial, family name). Author 1 Given name: [Jingjing] Last name [Chen], Author 2 Given name: [Yangmin] Last name [Gao], Author 3 Given name: [Shuzhen] Last name [Xiong], Author 4 Given name: [Ping] Last name [Zhan]. Also, kindly confirm the details in the metadata are correct.YesPlease check and confirm the inserted city and country are correctly identified for affiliation 3.Please change the affiliations, Affiliation 2: ²Jiangxi Provincial Clinical Research Center for Skin Diseases, Dermatology Hospital of Jiangxi Province,The Affiliated Dermatology Hospital of Nanchang University, Nanchang, 330200, Jiangxi; Affiliation 3: 3Institute of Clinical Medicine, Jiangxi Provincial People's Hospital, The First Affiliated Hospital of Nanchang Medical College,Nanchang 330001, Jiangxi. Thanks a lot!

Onychoscopic characteristics of Trichophyton rubrum and Trichophyton interdigitalis fungal infections: A multicentric study.

BACKGROUND: Trichophyton rubrum and Trichophyton mentagrophytes variant interdigitalis are the most frequent etiologic agents of onychomycosis. Diagnosis of certainty requires mycological examination, which often results unfeasible. OBJECTIVES: The aim of our study is to describe pathogen specific dermoscopic features, allowing a differential diagnosis without the need for cultural examination, in order to prescribe the most appropriate treatment anyway. PATIENTS AND METHODS: We conducted an observational retrospective study on 54 patients with a culture proven diagnosis of distal subungual onychomycosis of the toenail, caused by Trichophyton rubrum or Trichophyton mentagrophytes variant interdigitalis. Using a videodermatoscope we collected data on nail colour (white, yellow, orange, brown, dark) and on dermoscopic patterns (aurora, spikes, jagged, ruin, linear edge, dots, striae). RESULTS: Fifty-four patients, with a total of 72 nails, were eligible for this study. Analysing the association between discoloration of the nail plate and type of infection (T. rubrum or T. interdigitalis), no correlation turned out to be statistically significant. Instead, significant associations between spikes and T. rubrum infection and striae and infection from T. interdigitalis were identified. Finally, a 100% specificity was identified for white colour and ruin pattern for T. rubrum infection, and brown colour, jagged border and aurora pattern for T. interdigitalis. CONCLUSIONS: Trying to find relationships between specific pathogens and dermoscopic patterns, we found out an association between spikes and striae and T. rubrum and T. interdigitalis respectively. Further larger studies are however necessary to evaluate our preliminary findings.