Increasing Prevalence of Trichophyton rubrum Identified through an Analysis of 115,846 Cases over the Last 37 Years

Dermatophytosis caused by Nannizzia gypsea: report of 155 cases from Western Mexico

BACKGROUND

Dermatophytosis caused by Nannizzia gypsea are considered rare. The clinical picture is indistinguishable from that produced by other dermatophytes, but, being this a geophilic fungus, it can cause more inflammatory disease.

METHODS

Retrospective study. Patients with positive culture for N. gypsea observed at the Dermatological Institute of Jalisco "Dr. José Barba Rubio", from 2001 to 2023, were included. Frequency, sex, age, evolution, and clinical variant were investigated. We compared the findings between the pediatric versus adult population. Descriptive and inferential statistics were used.

RESULTS

Over 23 years, 155 patients were diagnosed (6.7 cases per year). Female sex predominated (53.5%). The median age was 9 years (minimum 1year and maximum 85 years), the more affected age group was 1-10 years (54.2%). The median time of evolution was 30 days (minimum one day and maximum three years), and 74.8% had an evolution ≤30 days. Tinea capitis predominated in pediatric patients (41.0%, p<0.01) whereas tinea corporis predominated in adults (72.7%, p<0.01). Inflammatory tinea was more prevalent in the pediatric population (21.0% vs. 3.6%, p<0.01).

CONCLUSION

The ability of Nannizzia gypsea to cause inflammatory tinea was observed primarily in pediatric patients. Since there is no clinical data to suspect this fungus, it will always be necessary to carry out a mycological study to identify the species and to implement the appropriate treatment.

Dermatophytes: Update on Clinical Epidemiology and Treatment

Dermatophytes represent the largest and most common group of fungal infections, impacting 25% of the global population. Among them, Trichophyton rubrum has emerged as the predominant species, responsible for a range of conditions such as tinea corporis, tinea pedis, onychomycosis, tinea cruris, and tinea manuum. Although dermatophyte incidence varies geographically, there is a noticeable rise in cases caused by T. indotineae, a strain that exhibits resistance to terbinafine. In the past decade zoophilic dermatophyte T. mentagophytes genotype VII (now known as T. interdigitale) gains a growing importance, due to its increasing frequency, the severity of the clinical manifestation and mode of transmission. Tinea infections present with various clinical symptoms and can affect individuals of all ages, from tinea pedis in adults to tinea capitis in children. Among adults globally, tinea unguium (onychomycosis) is the most common form of dermatophytosis, affecting 5.5% of the general population. Tinea unguium is more frequently seen in developed countries, while tinea capitis is more common in developing nations. The COVID-19 pandemic has led to an increase in cases of tinea faciei, likely due to prolonged mask-wearing. Terbinafine remains the preferred treatment for dermatophyte infections worldwide due to its potent fungicidal properties, minimal risk of drug interactions, and fewer side effects compared to other oral antifungals. Itraconazole and terbinafine appear to be equally effective and safe for treating tinea cruris and tinea corporis. However, the rising resistance of dermatophytes to these antifungal drugs, along with frequent recurrences of dermatophytosis in certain regions, is becoming a significant public health concern.

Epidemiological survey of 32,786 culture-positive dermatophytosis cases in Hangzhou from 2018 to 2023

BACKGROUND

With the rapid development of the economy and changes in lifestyle in recent years, the epidemiological pattern of dermatophytosis has changed. We analyzed the epidemiological features of dermatophytosis in a hospital in Hangzhou from 2018 to 2023.

METHODS

Data from patients with culture-positive dermatophytosis were obtained from the Laboratory Information System of the Mycology Laboratory of our hospital. Dermatophyte isolates were mainly identified by macroscopic and microscopic features of the colonies.

RESULTS

There were 32,786 patients with culture-positive dermatophytosis during the 6-year period, including 16,789 male patients and 15,990 female patients. Patients' ages ranged from 1 month to 97 years. Tinea unguium accounted for the largest proportion (14,879, 45.38%), which was mainly prevalent among females (8946, 60.13%). Significant gender differences were observed in all clinical types of dermatophytosis, except for tinea pedis. In total, 15,486 (47.73%) patients aged 21-40 years. The median age of patients with tinea manum and tinea capitis was the highest (49 years) and the lowest (5 years), respectively. Nine species of isolated dermatophytes were identified, of which Trichophyton rubrum accounted for 90.20% (29,573 cases). M. canis accounted for 66.80% of isolated dermatophytes from tinea capitis. The isolation rates of zoophilic species were 43.41% in tinea faciei and 18.90% in tinea corporis.

CONCLUSION

T. rubrum was absolutely predominant agent of dermatophytosis except tinea capitis in which M. canis was the most common organism. The prevalence of zoophilic dermatophytes has increased in tinea faciei and tinea corporis. Tinea unguium was the major clinical form of dermatophytosis, and it was more prevalent among females. The onset peak of dermatophytosis was in the age group of 21-40 years, except for tinea capitis.

Terbinafine Resistance in Trichophyton Strains Isolated from Humans and Animals: A Retrospective Cohort Study in Italy, 2016 to May 2024

Background: In recent decades, globalization and international migration have increased the spread of infectious agents, including dermatophytes. Although considered minor infections, dermatophytoses are highly contagious, and they significantly reduce the quality of life, inducing itching, burning, sleep disturbances, and even depressive states. Moreover, the increasing resistance to antifungals threats the public health and burdens the costs for the healthcare system. Methods: DermaGenius® Resistance Multiplex real-time PCR assay allowed to analyze the terbinafine susceptibility/resistance of 172 Trichophyton strains, which were isolated from human and animal samples collected from 2016 to May 2024 and previously identified by Sanger sequencing. Results: All the 11 animal strains belonged to the T. interdigitale/T. mentagrophytes complex and tested terbinafine sensitive. Out of 161 human strains, 9 (5.6%) showed terbinafine resistance and 7 (4.3%) were identified as T. indotineae. Conclusions: This study provides preliminary data about behavior toward antifungals in animals and finalizes the scientific information currently available about human strains, highlighting the importance of the One Health concept. Moreover, it supports the relevant role of T. indotineae as an emerging dermatophyte with high proportion of terbinafine resistance.

Efficacy of Laser Therapy in Comparison With Other Methods for the Treatment of Onychomycosis: A Systematic Review and Meta-Analysis

Onychomycosis, a fungal infection of the nails, presents a significant challenge in clinical management due to its chronic nature and resistance to conventional therapies. This study aims to evaluate the efficacy of laser therapy in treating onychomycosis compared to traditional methods such as terbinafine. A systematic review and meta-analysis were conducted to analyze existing literature on the subject. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) diagram illustrates the selection process of studies. Findings suggest that laser therapy demonstrates promising results in the treatment of onychomycosis, with comparable efficacy to terbinafine and fewer adverse effects. Further large-scale randomized controlled trials are warranted to validate these findings and establish laser therapy as a standard treatment option for onychomycosis.

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.

Dermatophyte Infections Worldwide: Increase in Incidence and Associated Antifungal Resistance

The increase in incidence of superficial fungal infections combined with the emergence of antifungal resistance represents both a global health challenge and a considerable economic burden. Recently, dermatophytes, the main culprit causing superficial fungal infections, have started to exhibit antifungal resistance. This can be observed in some of the most common species such as Trichophyton rubrum and Trichophyton mentagrophytes. Importantly, the new subspecies, known as Trichophyton indotineae, has been reported to show high resistance to terbinafine, a first-line treatment for dermatophyte infections. Compounding these issues is the realization that diagnosing the causative infectious agents requires using molecular analysis that goes beyond the conventional macroscopic and microscopic methods. These findings emphasize the importance of conducting antifungal susceptibility testing to select the appropriate antifungal necessary for successful treatment. Implementing these changes may improve clinical practices that combat resistant dermatophyte infections.

Erythroderma combined with deeper dermal dermatophytosis due to Trichophyton rubrum in a patient with myasthenia gravis: first case report and literature review

BACKGROUND

Dermatophytes are the most common causative pathogens of mycoses worldwide and usually cause superficial infections. However, they can enter deep into the dermis lead to invasive dermatophytosis such as deeper dermal dermatophytosis on rare occasions. Erythroderma is a severe dermatological manifestation of various diseases resulting in generalized skin redness, but erythroderma due to fungi infections is barely reported. In this article, we reported the first case of erythroderma combined with deeper dermal dermatophytosis due to Trichophyton rubrum (T. rubrum) in a patient with myasthenia gravis.

CASE PRESENTATION

A 48-year-old man was hospitalized because of erythema with scaling and nodules covering his body for a month. The patient had a history of myasthenia gravis controlled by regularly taking prednisolone for > 10 years and accompanied by onychomycosis and tinea pedis lasting > 8 years. Based on histopathological examinations, fungal cultures, and DNA sequencing results, the patient was finally diagnosed with dermatophyte-induced erythroderma combined with deeper dermal dermatophytosis caused by T. rubrum. After 2 weeks of antifungal treatment, the patient had recovered well.

CONCLUSIONS

This case report shows that immunosuppressed patients with long histories of superficial mycoses tend to have a higher risk of developing invasive dermatophytic infections or disseminated fungal infections. Dermatologists should be alert to this condition and promptly treat the superficial dermatophytosis.

Cutaneous Fungal Infections Caused by Dermatophytes and Non-Dermatophytes: An Updated Comprehensive Review of Epidemiology, Clinical Presentations, and Diagnostic Testing

Cutaneous fungal infection of the skin and nails poses a significant global public health challenge. Dermatophyte infection, mainly caused by Trichophyton spp., is the primary pathogenic agent responsible for skin, hair, and nail infections worldwide. The epidemiology of these infections varies depending on the geographic location and specific population. However, epidemiological pattern changes have occurred over the past decade. The widespread availability of antimicrobials has led to an increased risk of promoting resistant strains through inappropriate treatment. The escalating prevalence of resistant Trichophyton spp. infections in the past decade has raised serious healthcare concerns on a global scale. Non-dermatophyte infections, on the other hand, present even greater challenges in terms of treatment due to the high failure rate of antifungal therapy. These organisms primarily target the nails, feet, and hands. The diagnosis of cutaneous fungal infections relies on clinical presentation, laboratory investigations, and other ancillary tools available in an outpatient care setting. This review aims to present an updated and comprehensive analysis of the epidemiology, clinical manifestations, and diagnostic testing methods for cutaneous fungal infections caused by dermatophytes and non-dermatophytes. An accurate diagnosis is crucial for effective management and minimizing the risk of antifungal resistance.

A Dual-Plasmid-Based CRISPR/Cas9-Mediated Strategy Enables Targeted Editing of pH Regulatory Gene pacC in a Clinical Isolate of Trichophyton rubrum

Trichophyton rubrum is the most prevalent causative agent responsible for 80-90% of all known superficial fungal infections in humans, worldwide. Limited available methods for genetic manipulations have been one of the major bottlenecks in understanding relevant molecular mechanisms of disease pathogenesis in T. rubrum. Here, a dual-plasmid-based CRISPR/Cas9 strategy to edit pH regulatory transcription factor, pacC, of a clinical isolate of T. rubrum by non-homologous end joining (NHEJ) repair is presented. A cas9-eGFP fusion that aids pre-screening of primary transformants through detection of GFP fluorescence is expressed from one plasmid while target-specific sgRNA from the other brings about mutagenesis of pacC with an overall efficiency of 33.8-37.3%. The mutants had reduced transcript levels of pacC at both acidic and alkaline pH with several morphological abnormalities. We believe this dual-plasmid-based CRISPR/Cas9 strategy will aid functional genomics studies, especially in non-lab-adapted clinical strains of T. rubrum.

Genome-wide identification and functional analysis of circRNAs in Trichophyton rubrum conidial and mycelial stages

Background

Circular RNAs (circRNAs) are a group of noncoding RNAs that participate in gene expression regulation in various pathways. The essential roles of circRNAs have been revealed in many species. However, knowledge of circRNAs in fungi is still not comprehensive.

Results

Trichophyton rubrum (T. rubrum) is considered a model organism of human pathogenic filamentous fungi and dermatophytes. In this study, we performed a genome-wide investigation of circRNAs in T. rubrum based on high-throughput sequencing and ultimately identified 4254 circRNAs. Most of these circRNAs were specific to the conidial or mycelial stage, revealing a developmental stage-specific expression pattern. In addition, 940 circRNAs were significantly differentially expressed between the conidial and mycelial stages. PCR experiments conducted on seven randomly selected differentially expressed (DE-) circRNAs confirmed the circularized structures and relative expression levels of these circRNAs. Based on their genome locations, most circRNAs originated from intergenic regions, unlike those in plants and animals. Furthermore, we constructed circRNA-miRNA-mRNA regulatory networks that included 661 DE-circRNAs targeting 140 miRNAs and further regulating 2753 mRNAs. The relative expression levels of two randomly selected circRNA-miRNA-mRNA axes were investigated by qRT-PCR, and the competing endogenous RNA (ceRNA) network theory was validated. Functional enrichment analysis of the target genes suggested that they were significantly involved in posttranscriptional processes and protein synthesis as well as some small-molecule metabolism processes. CircRNAs are relatively more conserved in closely related dermatophytes but rarely conserved in distantly related species. Tru_circ07138_001 is a highly conserved circRNA that was conserved in all ten dermatophytes analyzed in our study and three distantly related species. Its host gene TERG_07138 was also highly conserved in two of these distantly related species Gallus gallus and Caenorhabditis elegans. The specific role of this circRNA deserves further exploration.

Conclusions

Our study is the first to provide a global profile of circRNAs in T. rubrum as well as dermatophytes. These results could serve as valuable resources for research on circRNA regulatory mechanisms in fungi and reveal new insights for further investigation of the physical characteristics of these significant human fungal pathogens.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12864-021-08184-y.

Epidemiology of Dermatophytes Isolated from Clinical Samples in a Hospital in Eastern Saudi Arabia: A 20-Year Survey

BACKGROUND

Dermatophytes are group of fungi that cause superficial infections via enzymes that degrade keratin in human skin. Several factors, including climate, gender, age, lifestyle, human migration, cultural habits, and socioeconomic status influence the prevalence of dermatophyte infections. We analyzed the prevalence of dermatophyte isolates in a hospital in Eastern Saudi Arabia from 2000 to 2019.

METHODS

The data on fungal cultures were obtained from the Laboratory Information System of the Mycology Laboratories at Johns Hopkins Aramco Healthcare, and were used for the analysis. Fungal isolates were examined microscopically for the presence of specialized hyphal structures and conidia. The Vitek^® MS microbial identification system (biomerieux) was used if the culture type was not identified microscopically.

RESULTS

Among the 10,021 samples analyzed, 3040 (30.33%) were positive for fungi and only 398 (3.97%) were dermatophytes. Microsporum species was the most common dermatophyte accounting for 50.5% (n = 201) followed by trichophyton with 36.9% (n = 147). The most common positive samples were scrapping (251, 63%) and hair (68, 17%). Culture positivity relative to the age groups revealed a cluster of positive dermatophyte species in children < 10 years of age with 215 (54%) of all cases and among 10-19 years of age with 60 (15) of the cases (p < 0.001). Microsporum species were the prevalent dermatophytes in patients  < 10 years of age, while Epidermophyton species were the most frequent dermatophyte species in age groups 10-19, 20-29, and 30-39 years. However, Trichophyton species were the most frequent dermatophyte species in individuals 70-79 years. The percentage of Microsporum and Trichophyton species decreased significantly over time (p < 0.001). In addition, there was a significant seasonal variation in relation to Trichophyton species. A comparison between the most frequent species showed that there was no difference in relation to gender, but there was a difference in relation to the specimen type and age group.

CONCLUSION

Dermatophytosis was common among children and adolescent with the most common samples were scrapping and hair. There was a significant reduction in Microsporum and Trichophyton species over time.

Epidemiology of Dermatophytes in Belgium: A 5 Years' Survey

Dermatophytes are among the most common fungal agents causing superficial skin infections worldwide. Epidemiology of these infections is evolving and variable in every country. This report presents the Belgian epidemiological data regarding the distribution of dermatophytes species isolated by the two national reference centers for mycosis during a period of 5 years (2012-2016). Trichophyton rubrum was the most frequently isolated species, considering all sampling sites (60.3% on average between 2012 and 2016). More precisely, this dermatophyte was the major agent of Tinea unguium and Tinea corporis during this period, followed by species of the Trichophyton mentagrophytes complex. Moreover, Microsporum audouinii was the main etiological agent of Tinea capitis (TC) with a frequency of 52.5% on average between 2012 and 2016. Other African dermatophytes species such as Trichophyton soudanense and Trichophyton violaceum were also agents of TC with a respective prevalence of 11.6% and 11.5% on average. This study highlights a different dermatophyte distribution in Belgium in comparison with other European countries.

Epidemiology of dermatophytoses in paediatric population in Southwestern Poland, 2011-2016

INTRODUCTION

Dermatophytoses are the most common superficial fungal infections in paediatric population. Its pathogen pattern has changed over years.

AIM

To analyse the spectrum of dermatophytoses in children living in Southwestern Poland, in the years 2011-2016.

MATERIAL AND METHODS

A total of 1705 patients were diagnosed with fungal skin infection in the Mycological Laboratory, Dermatology Department of the Wroclaw Medical University. Of them, 163 were under 18 years of age.

RESULTS

In 105 cases, dermatophytoses were detected. The collected specimens were examined using direct microscopy examination, staining, culture on specific media and PCR technique. The most common dermatophytes were Trichophyton rubrum and Trichophyton tonsurans (31.4% each), followed in the descending order by Trichophyton mentagrophytes (21.9%), Microsporum canis (13.3%) and Epidermophyton floccosum (1.9%). The most commonly affected body sites were glabrous skin of the trunk and extremities (41.7%), followed by face (22.2%), scalp (15.7%) and toe nails (14.8%).

CONCLUSIONS

This study revealed the most common types of dermatophytoses and their pathogens in children in Southwestern Poland. In comparison to earlier data obtained from this region, new epidemiological trends have been revealed. We observed the shift towards anthropophilic dermatophyte infections and an increasing number of onychomycosis in children. Because of climatic variations, migration, and changing lifestyle practices, further studies on dermatophytoses are necessary to improve our knowledge on the epidemiology of fungal infections.

Antifungal activity and potential mechanism of magnoflorine against Trichophyton rubrum

Coptis alkaloids show potent antifungal activity against Trichophyton rubrum (T. rubrum), which was a Tinea pedis fungus, but little of the literature was reported to investigate the antifungal activity of magnoflorine against it. Meanwhile, the potential mechanism of magnoflorine against T. rubrum is unknown. In the present study, we found that Coptis alkaloids, especially magnoflorine had significant antifungal activities against T. rubrum and Trichophyton mentagrophyte (T. mentagrophyte). The MIC values of magnoflorine against T. rubrum and T. mentagrophyte were both 62.5 μg ml^-1, but magnoflorine exerted a better fungicidal efficiency against T. rubrum than T. mentagrophyte. Magnoflorine inhibited the conidia germination and hyphal growth, and changed the mycelial morphology such as deformation growth, surface peeling, and cytoplasmic contraction in T. rubrum. Magnoflorine had no significant effect on cell wall integrity. However, magnoflorine destroyed the fungal cell membrane of T. rubrum through increasing the nucleic acid leakage, reducing the activities of squalene epoxidase and CYP51 enzyme, and decreasing the content of ergosterol in hyphae. Our study supported the potential use of magnoflorine as an antifungal agent against T. rubrum and made contributions to the clinical application of magnoflorine against fungi.

Analysis of Adult Patients with Tinea Capitis in Southeastern Korea

Background

Tinea capitis is a cutaneous infection of dermatophytes and predominant in children. Although tinea capitis in Korea is controlled by oral antifungal medications and concerted public health initiatives, it's still a health issue.

Objective

To investigate changes in the epidemiological and mycological characteristics of adult patients with tinea capitis in southeastern Korea.

Methods

Using medical records from Kyungpook National University Hospital and Catholic Skin Clinic from 1989 to 2018, we retrospectively investigated the epidemiological and mycological characteristics of 266 adult patients (aged over 20) with tinea capitis.

Results

Among total 266 patients, 239 were KOH-positive. The annual incidence of tinea capitis ranged from 3 to 18 between 1989 and 2018. Of the total, 54 (20.30%) were male and 212 (79.70%) were female. Eighty patients (30.08%) were in their seventies, the most commonly affected age group. Of the remaining, 58 (21.80%) were in their sixties, and 41 (15.41%) in eighties. Among all, 77 (28.95%) visited the hospital in summer, 72 (27.07%) in spring, 64 (24.06%) in winter, and 53 (19.92%) in fall. Dermatophytes were cultured from 171 patients. Microsporum canis was the most common dermatophyte (42.48%), while Trichophyton rubrum was the second (15.79%). Of the 266 patients, 186 (69.92%) lived in urban areas and 80 (30.08%) in rural areas.

Conclusion

The epidemiological and mycological characteristics of adult patients with tinea capitis were different from those of children in terms of annual incidence, sex distribution, and isolated dermatophytes. These results provide useful information for the treatment and prevention of tinea capitis.

Trichophyton rubrum Elicits Phagocytic and Pro-inflammatory Responses in Human Monocytes Through Toll-Like Receptor 2

Dermatophytosis is a superficial fungal infection mostly restricted to keratinized tissues such as skin, hair, and nails but with potential to cause invasive or even systemic disease in immunocompromised patients. Trichophyton rubrum is the main etiologic agent, accounting for approximately 80% of the cases. Mononuclear phagocytes respond to pathogens through phagocytosis followed by production of several antimicrobial molecules, such as reactive oxygen and nitrogen species, and failure in doing so may contribute to development of chronic fungal infections. Toll-like receptors (TLRs) located on the surface of phagocytic cells bind either directly to target particles or through opsonizing ligands and trigger an actin-mediated ingestion. Even though the mechanisms involved in TLR-mediated cytokine responses are well established, the contribution of TLR in the recognition of T. rubrum by adherent monocytes remains unclear. Here, we report that phagocytosis of T. rubrum conidia by adherent monocytes is mediated by TLR2. Blockade of TLR2 by neutralizing antibodies impaired the fungicidal activity of monocytes as well their secretion of tumor necrosis factor (TNF)-α, but neither nitric oxide (NO) production nor interleukin (IL)-10 secretion was disturbed. So far, our data suggest that TLR2 is required for efficient conidial phagocytosis, and the absence of TLR2 signaling in human monocytes may impair the subsequent inflammatory response. These findings expand our understanding of phagocyte modulation by this important fungal pathogen and may represent a potential target for interventions aiming at enhancing antifungal immune responses.

Internal environment of footwear is a risk factor for tinea pedis

The relation between tinea pedis and the internal environment of footwear has not been scientifically proven. This study aimed to determine whether the internal environment of footwear affects the incidence of tinea pedis and tinea unguium. This cross-sectional, observatory study involved 420 outpatients who were categorized into non-tinea, tinea pedis or tinea unguium groups based on mycological analysis. External climatic conditions, and temperature, humidity and dew points inside the patients' footwear were recorded. Univariate and multivariate analyses were used to determine independent risk factors for tinea pedis and tinea unguium. A significant correlation was found between high temperature/high humidity and dew point of the internal environment of the footwear and the season. Furthermore, those who wore footwear with internal environments characterized by high temperature, high humidity, high-temperature/high-humidity and high dew point values had a significantly higher incidence of tinea pedis. The internal dew point correlated with the incidence of tinea pedis, whereas the external temperature correlated with the incidence of tinea unguium. The internal humidity and dew point of footwear as well as the frequency with which footwear with a high-temperature/high-humidity internal environment were worn was significantly higher in men than in women. In conclusion, the internal environment of footwear is a risk factor for tinea pedis, and this environment is affected by the season. Moreover, the frequency of tinea pedis among men is related to the internal environment of footwear. The dew point is an appropriate index for evaluating temperature and humidity in relation to tinea pedis.

Prevalence and distribution of dermatophytosis lesions on cattle in Plateau State, Nigeria

Background and Aim:

Dermatophytosis is an infection of the superficial, keratinized structures of the skin, nails, and hair of man and animals caused by a group of fungi called dermatophytes in the genera Trichophyton, Microsporum, and Epidermophyton. The prevalence of dermatophytosis among cattle in Nigeria and Plateau State, in particular, is yet to be fully determined. This study aimed to determine the prevalence and the distribution of dermatophytosis lesions on cattle in Plateau State, Nigeria.

Materials and Methods:

Four hundred and thirty-seven cattle showing visible skin lesions suggestive of dermatophytosis were drawn from nine local government areas (three each) from the three senatorial districts of Plateau State, Nigeria. Skin scrapings were aseptically collected using a cross-sectional study, in which sampling units were selected using purposive sampling method. Samples were processed for both direct microscopic examination and isolation of dermatophytes in culture. The isolates were stained with lactophenol cotton blue and identified microscopically based on the size, shape, and arrangement of macro- and micro-conidia. The dermatophytes were further identified by determining the sequences of the internal transcribed spacer regions of their ribosomal DNA. Data were analyzed and presented as percentages, bar graph, and Chi-square test of association. p≤0.05 was considered statistically significant.

Results:

The overall prevalence rate of bovine dermatophytosis in Plateau State was found to be 11.0%. Trichophyton verrucosum was more frequently isolated (54.2%) than Trichophyton mentagrophytes (45.8%). Age, breed, management practice, and season were significantly associated with the occurrence of the disease (p<0.05).

Conclusion:

Dermatophytosis among cattle may be of public health significance in Plateau State, Nigeria. This is the first report on the prevalence and distribution of dermatophytosis lesions on cattle from Plateau State, Nigeria.

In vitro models of dermatophyte infection to investigate epidermal barrier alterations

Fungal infections of the skin, known as dermatophytoses, are initiated at the epidermal barrier and lead to dysfunctions of the stratum corneum and cornified skin appendages. Dermatophytosis affects a significant part of the human population and, despite the availability of effective treatments, its prevalence is still increasing. Numerous dermatophyte species are able to induce lesions in both animals and humans, with different clinical pictures and host inflammatory responses. The understanding of the infectious process and of tissue responses has been impeded by discrepancies between observations in vivo or in research models. Indeed, cells cultured as monolayers do not undergo the keratinization process required to study the adherence and invasion of dermatophytes. Animal models lack relevance to study human dermatophytosis because of species-specific differences in the development of lesions and inflammatory responses. This review focuses on the recent development of cultured human skin equivalents, which partly overcomes those limitations and allows improved understanding of the pathogenesis of dermatophytosis in human being, especially the impacts of infection on epidermal barrier integrity.

Responses of Reconstructed Human Epidermis to Trichophyton rubrum Infection and Impairment of Infection by the Inhibitor PD169316

Despite the threatening incidence of dermatophytosis, information is still lacking about the consequences of infection on epidermal barrier functions and about the keratinocyte responses that alert immune components. To identify the mechanisms involved, arthroconidia of the anthropophilic dermatophyte Trichophyton rubrum were prepared to infect reconstructed human epidermis (RHE) in vitro. Integrity of the barrier was monitored during infection by measurements of transepithelial electrical resistance and dye-permeation through the RHE. Expression and release of pro-inflammatory cytokines and antimicrobial peptides by keratinocytes inserted into the RHE were assessed, respectively, by quantitative reverse transcriptase-PCR (to analyze mRNA content in tissue extracts) and by ELISA (to detect proteins in culture media). Results reveal that infection by T. rubrum is responsible for disruption of the epidermal barrier, including loss of functional tight junctions. It additionally causes simultaneous expression and release of cytokines and antimicrobial peptides by keratinocytes. Potential involvement of the p38 mitogen-activated protein kinase signaling pathway was evaluated during infection by targeted inhibition of its activity. Intriguingly, among several p38 mitogen-activated protein kinase inhibitors, PD169316 alone was able to inhibit growth of T. rubrum on Sabouraud agar and to suppress the process of infection on RHE. This suggests that PD169316 acts on a specific target in dermatophytes themselves.

Challenges and Opportunities in the Management of Onychomycosis

Onychomycosis is an increasingly common fungal nail infection, chiefly caused by dermatophyte fungi. The disease is notoriously difficult to treat due to the deep-seated nature of fungi within the nail plate, prolonged treatment requirements, poor patient adherence and frequent recurrences. Given the poor efficacy of currently available topical and systemic therapies, there is a renewed interest in exploring alternative treatment modalities for onychomycosis. Natural therapies, physical treatments and various combination therapies have all shown potential for the management of onychomycosis, though research on many of these methods is still in preliminary stages. Further large, well-designed, randomised controlled trials are necessary to confirm the efficacy of these novel treatments in order to make formal recommendations regarding their use in the management of onychomycosis.

Low But Continuous Occurrence of Microsporum gypseum Infection in the Study on 198 Cases in South Korea from 1979 to 2016

Background

Microsporum gypseum has been isolated from South Korea since 1966. However, the incidence of M. gypseum infection is very low.

Objective

The aim of this study is to add massive data on M. gypseum to the literature and to provide useful information on clinical and mycological characteristics of M. gypseum.

Methods

We retrospectively analyzed data of 198 cases infected with M. gypseum from 1979 to 2016. The identification of M. gypseum was done with mycological examination using 15% KOH preparation and potato corn meal tween 80 agar culture media.

Results

The incidence of M. gypseum infection was very low in South Korea, showing a tendency to decrease. Out of 198 cases, men were 94 cases (47.5%) and women were 104 cases (52.5%). Mean age of all patients was 29.83 years old: 24.97 years old in men and 34.22 years old in women. M. gypseum infection occurred most frequently in September (16.7%) and August (16.2%). The most common clinical type of M. gypseum infection was tinea corporis (38.4%).

Conclusion

M. gypseum infection shows very low incidence but still remains around us until recent years. We should keep in mind the characteristics of M. gypseum.

The influence of immune status, age, and sex on Majocchi granuloma: a review of 52 cases from a tertiary level hospital and published Korean cases in literature

BACKGROUND

Majocchi granuloma (MG) is a rare dermal and subcutaneous granulomatous inflammation caused by dermatophytes. The detailed characteristics of MG are not fully elucidated. This study investigated the influence of systemic immune status, age, and sex on the clinical, demographic, mycological, and therapeutic characteristics of MG in Korea.

METHODS

We analyzed cases of histopathologically diagnosed MG at our tertiary referral center from January 2001 to December 2016. We also analyzed all Korean MG cases published in Korean and English literature to date. The different features based on immune status, age, and sex were compared. P < 0.05 were considered statistically significant.

RESULTS

We enrolled 52 patients, 33 (63.5%) were male and 19 (36.5%) were female. The mean age was 45.4 ± 23.1 years. Immunosuppression was reported in 13 cases (26.5%). Statistical analysis showed that the immune status affects the anatomical location and clinical manifestation. Age has an influence on involved sites and identified fungal species. The frequent fungal pathogens were different based on sex.

CONCLUSION

The results of our study revealed that distinctive features of MG exist based on immune status, age, and sex.

Distribution of Species of Dermatophyte Among Patients at a Dermatology Centre of Nghean Province, Vietnam, 2015-2016

INTRODUCTION

Vietnam is a tropical country so fungal diseases including dermatophytosis may be prevalent, but epidemiological profiles of agents responsible for the infection have rarely been reported.

OBJECTIVE

To find out the distribution of dermatophytes among patients living in a central province of Vietnam.

METHODS

We examined dermatophyte infections in patients with lesions suspected of dermatophytosis referred to the Nghean provincial leprosy and dermatology centre from August 2015 to August 2016. The speciation of dermatophyte was performed by conventional and molecular approaches.

RESULTS

One hundred and thirty-six patients (90 males and 46 females) were included. Those aged from 11 to 30 contribute 59.1%. The most common agent found was Trichophyton rubrum (66.9%), followed by T. interdigitale (12.5%), T. tonsurans (9.6%), Microsporum incurvatum (8.1%), and the less frequent species were M. canis (2.2%) and T. violaceum (0.7%). Epidermophyton floccosum was not reported. T. rubrum were more common in men (74.4%) than in women (52.2%), while T. interdigitale and M. incurvatum were more common in women (21.7 and 15.2%) than in men (7.8 and 4.4%). Patients infected with Microsporum spp. had small-sized lesions for only 3 months, while those affected by Trichophyton spp. had large-sized lesions with longer duration.

CONCLUSION

Trichophyton species are the predominant agents of infection in Nghean province, while Epidermophyton species is absent. Additional investigations are required to clarify the epidemiological profile of dermatophytes in Vietnam.

The Changing Epidemiology of Invasive Fungal Infections

Invasive fungal infections (IFI) are an emerging problem worldwide with invasive candidiasis and candidemia responsible for the majority of cases. This is predominantly driven by the widespread adoption of aggressive immunosuppressive therapy among certain patient populations (e.g., chemotherapy, transplants) and the increasing use of invasive devices such as central venous catheters (CVCs). The use of new immune modifying drugs has also opened up an entirely new spectrum of patients at risk of IFIs. While the epidemiology of candida infections has changed in the last decade, with a gradual shift from C. albicans to non-albicans candida (NAC) strains which may be less susceptible to azoles, these changes vary between hospitals and regions depending on the type of population risk factors and antifungal use. In certain parts of the world, the incidence of IFI is strongly linked to the prevalence of other disease conditions and the ecological niche for the organism; for instance cryptococcal and pneumocystis infections are particularly common in areas with a high prevalence of HIV disease. Poorly controlled diabetes is a major risk factor for invasive mould infections. Environmental factors and trauma also play a unique role in the epidemiology of mould infections, with well-described hospital outbreaks linked to the use of contaminated instruments and devices. Blastomycosis is associated with occupational exposure (e.g., forest rangers) and recreational activities (e.g., camping and fishing).The true burden of IFI is probably an underestimate because of the absence of reliable diagnostics and lack of universal application. For example, the sensitivity of most blood culture systems for detecting candida is typically 50 %. The advent of new technology including molecular techniques such as 18S ribosomal RNA PCR and genome sequencing is leading to an improved understanding of the epidemiology of the less common mould and dimorphic fungal infections. Molecular techniques are also providing a platform for improved diagnosis and management of IFI.Many factors affect mortality in IFI, not least the underlying medical condition, choice of therapy, and the ability to achieve early source control. For instance, mortality due to pneumocystis pneumonia in HIV-seronegative individuals is now higher than in seropositive patients. Of significant concern is the progressive increase in resistance to azoles and echinocandins among candida isolates, which appears to worsen the already significant mortality associated with invasive candidiasis. Mortality with mould infections approaches 50 % in most studies and varies depending on the site, underlying disease and the use of antifungal agents such as echinocandins and voriconazole. Nevertheless, mortality for most IFIs has generally fallen with advances in medical technology, improved care of CVCs, improved diagnostics, and more effective preemptive therapy and prophylaxis.

Dermatophyte abscesses caused by Trichophyton rubrum in a patient without pre-existing superficial dermatophytosis: a case report

BACKGROUND

Trichophyton usually causes a superficial skin infection, affecting the outermost layer of the epidermis, the stratum corneum. In immunocompromised patients, deeper invasion into the dermis and even severe systemic infection with distant organ involvement can occur. Most cases of deeper dermal dermatophytosis described in the literature so far involved pre-existing superficial dermatophytosis.

CASE PRESENTATION

We report a 68-year-old woman presented to our clinic with a 3-month history of palpable nodules on the right ankle without pre-existing superficial dermatophytosis. Magnetic resonance imaging showed multiple, well-demarcated, cystic lesions around the lateral malleolus, located in the subcutaneous or dermal layers. The sizes varied from 0.5 cm to 4 cm in diameter. The patient underwent complete excision of the lesions. Fungal culture yielded Trichophyton rubrum on Sabouraud dextrose agar. Histopathology showed organizing abscesses with degenerated fungal hyphae. After the 12-week oral itraconazole therapy, the lesions were completely resolved.

CONCLUSION

Dermatophytes should be considered as a possible cause of deep soft tissue abscesses in immunocompromised patients, even though there is no superficial dermatophytosis lesion.