Invasive dermatophyte infection: A systematic review

Octyl succinic anhydride-modified chitosan/oxidized sodium alginate Schiff base hydrogel loaded with terbinafine hydrochloride: pH-responsive, self-repairing, antifungal properties

The application of hydrogels to drug delivery limited by the difficulty of encapsulating hydrophobic drugs; therefore, the development of novel composite hydrogels for the delivery of hydrophobic drugs is urgently needed. In this study, terbinafine hydrochloride/hydroxypropyl-β-cyclodextrin inclusion complexes (TFH/HP-β-CD ICs) were added to a Schiff base hydrogel matrix containing octenyl succinic anhydride-modified chitosan (OSA-CS) and sodium alginate (OIA) to prepare a TFH composite hydrogel (TFH GEL). The results revealed that the solubility of TFH in water within TFH/HP-β-CD IC reached 32.13 mg/mL. The TFH GEL successfully encapsulated the IC without any drug leakage and exhibited excellent acid pH responsiveness. Moreover, the hydrogels were mechanically stable, self-healing, and injectable. Haemocompatibility and cytotoxicity tests confirmed the excellent biocompatibility of the TFH GEL. Importantly, TFH GEL effectively inhibited Microsporum canis growth in vitro and in vivo. In summary, a novel composite hydrogel was developed by combining a modified natural polymer hydrogel with a complexing agent to deliver the hydrophobic antifungal drug TFH, this study provides a new strategy for treating fungal skin infections.

An Introduction to the Influence of Nutritional Factors on the Pathogenesis of Opportunist Fungal Pathogens in Humans

Fungi such as Aspergillus fumigatus, Candida albicans, and Cryptococcus neoformans are opportunistic pathogens in humans. They usually infect individuals whose immune system is compromised due to either a primary infection, e.g., HIV/AIDS, or as part of treatment for another condition, e.g., stem cell or solid organ transplant. In hosts with a weakened immune system, these fungi can cause life-threatening infections. Unlike true pathogens, opportunistic pathogens do not have specific mechanisms to overcome a healthy host, requiring a different approach to understand how they cause infection. The ability of fungi to adapt to various environmental conditions, including the human host, is critical for virulence. In humans, micronutrient metals, such as iron, are sequestered to reduce serum concentrations, which helps to inhibit microbial growth. Other human tissues may increase metal concentrations to toxic levels to prevent infection by pathogens. The ability of fungi to acquire or detoxify nutrients, such as iron or copper, from the host is essential for the establishment of infection. In this review, the role of fungal nutrition will be discussed in relation to opportunistic fungal pathogens. It will focus on the acquisition of micronutrients, e.g., iron, copper, and zinc, and how this enables these fungi to circumvent host nutritional immunity.

Correlation analysis between IL-1R/TLRs pathway and superficial dermatomycosis

OBJECTIVE

This study explored the correlation between interleukin-1 receptor/Toll-like receptor (IL-1R/TLRs)-mediated inflammatory signaling pathways and the severity of superficial dermatomycosis.

METHODS

From May 2020 to August 2022, 76 patients with superficial dermatomycosis (infected group) and 52 patients without infection (non-infected group) were enrolled. The indicators related to IL-1R/TLRs pathway were analyzed, and the diagnostic value of the combined detection of each index for superficial dermatomycosis and disease severity was analyzed. The correlation between each index and the severity of infection was analyzed.

RESULTS

IL-1β, TLR4, IL-6, and TNF-α in the infected group were higher than those in the non-infected group (P < 0.05). The AUC of IL-1R/TLRs combined detection in the group diagnosed with a superficial dermatomycosis was higher than that of each single detection (P < 0.05). IL-1β, TLR4, IL-6, and TNF-α in the severe group were higher than those in the mild group (P < 0.05). IL-1β, TLR4, IL-6, and TNF-α were positively correlated with the degree of infection (P < 0.05). The AUC of IL-1R/TLRs combined detection was higher than that of each single test (P < 0.05). IL-1β ≥ 2.87 ng/L, TLR4 ≥ 3.12 ng/L, IL-6 ≥ 4.58 ng/L, TNF-α ≥ 70.53 ng/L were the influencing factors of severe superficial dermatomycosis (P < 0.05).

CONCLUSION

IL-1R/TLRs pathway is related to the severity of superficial dermatomycosis, and the collective identification of each indicator provides diagnostic insight into infection severity.

Global Insights and Trends in Research on Dermatophytes and Dermatophytosis: A Bibliometric Analysis

BACKGROUND

Dermatophytosis, caused by dermatophytes, affects up to 25% of people globally, with higher rates observed in Africa and Asia. While these infections are usually superficial, they can become severe in immunocompromised individuals. Despite their high prevalence, scientific research on dermatophytes is limited and the epidemiological data available are insufficient. In addition, diagnostic methods are not standardised and there are challenges with resistance to antifungals.

OBJECTIVES

This study aimed to conduct a bibliometric analysis of scientific publications related to dermatophytes and dermatophytosis to assess research output and trends.

METHODS

A bibliometric analysis of publications from 2000 to 2023 in Web of Science and Scopus examined trends, citation counts, publication types, key journals, top authors and institutions and funding sources.

RESULTS

The analysis revealed a significant increase in dermatophyte-related publications, with 15,868 articles retrieved from the Web of Science and 23,189 from Scopus. Research articles dominated the output, constituting 76.2% in Web of Science and 80% in Scopus. Peak publication years were 2019, 2021 and 2022 in Web of Science, and 2020, 2021 and 2023 in Scopus, with lower output between 2000 and 2002. The United States and India were the leading contributors, followed by Brazil and China, though citation metrics varied. Although there has been a rise in the number of publications, the amount of research conducted on dermatophytes is still very limited in comparison with other types of fungal diseases.

CONCLUSIONS

Dermatophyte-related research has increased over the past 2 decades. However, research gaps remain, particularly compared with other fungal diseases. Advances in diagnostics, antifungal testing and taxonomic classification are urgently needed. The study underscores the need for continued research and global collaboration to address these issues.

Host-Pathogen Interaction and Resistance Mechanisms in Dermatophytes

Dermatophytes are widely distributed in the environment, with an estimated prevalence of 20-25% of the the global population yearly. These fungi are keratinophilic and keratinolytic and cause the infection of keratin-rich structures such as skin, hair, and nails. The pattern of this infectious disease covers a wide spectrum from exposed individuals without symptoms to those with acutely inflammatory or non-inflammatory, chronic to invasive, and even life-threatening symptoms. This review summarizes current information on the pathogenicity, virulence factors, and drug resistance mechanisms associated with dermatophytes. A greater number of virulence factors of these fungi are important for the occurrence of infection and the changes that occur, including those regarding adhesins, the sulfite efflux pump, and proteolytic enzymes. Other virulence factors include mechanisms of evading the host defense, while the development of resistance to antifungal drugs is increasing, resulting in treatment failure. The investigation of host-pathogen interactions is essential for developing a more complete understanding of the mechanisms underlying dermatophyte pathogenesis and host response to inform the use of diagnostics methods and antifungal therapeutics to minimize the high fungal burden caused by dermatophytes and to control the spread of resistance.

Expert Panel Review of Skin and Hair Dermatophytoses in an Era of Antifungal Resistance

Dermatophytoses are fungal infections of the skin, hair, and nails that affect approximately 25% of the global population. Occlusive clothing, living in a hot humid environment, poor hygiene, proximity to animals, and crowded living conditions are important risk factors. Dermatophyte infections are named for the anatomic area they infect, and include tinea corporis, cruris, capitis, barbae, faciei, pedis, and manuum. Tinea incognito describes steroid-modified tinea. In some patients, especially those who are immunosuppressed or who have a history of corticosteroid use, dermatophyte infections may spread to involve extensive skin areas, and, in rare cases, may extend to the dermis and hair follicle. Over the past decade, dermatophytoses cases not responding to standard of care therapy have been increasingly reported. These cases are especially prevalent in the Indian subcontinent, and Trichophyton indotineae has been identified as the causative species, generating concern regarding resistance to available antifungal therapies. Antifungal-resistant dermatophyte infections have been recently recognized in the United States. Antifungal resistance is now a global health concern. When feasible, mycological confirmation before starting treatment is considered best practice. To curb antifungal-resistant infections, it is necessary for physicians to maintain a high index of suspicion for resistant dermatophyte infections coupled with antifungal stewardship efforts. Furthermore, by forging partnerships with federal agencies, state and local public health agencies, professional societies, and academic institutions, dermatologists can lead efforts to prevent the spread of antifungal-resistant dermatophytes.

Osteomyelitis by Microsporum canis and Staphylococcus spp. in cat (Felis catus) - case report

BACKGROUND

Staphylococcus spp and Microsporum canis are zoonotic microorganisms which can cause infections and systemic diseases. The bone infection is usually caused by invasion of pathogen through the hematologic route. Mixed osteomyelitis caused by bacteria and fungi is rare, and to date, there have been no reports of mixed osteomyelitis with Staphylococcus spp. and Microsporum canis.

CASE PRESENTATION

This essay reports an atypical presentation of mixed osteomyelitis (Staphylococcus spp. and Microsporum canis) in a domestic cat. A 15-month-old female Persian cat was presented to a veterinary service; the main complaint was the appearance of a nodule in the mandibular ventral rostral region. A radiographic exam performed on the animal showed proliferative and osteolytic bone lesions. The patient was submitted to a biopsy for histopathological evaluation, along with bacterial and fungal cultures. Results showed mixed osteomyelitis by Staphylococcus spp. and Microsporum canis. Microbial Sensitivity Test was performed to choose a more suitable treatment. Two surgical procedures were executed to resect and curette the lesion, and treatments with anti-inflammatory, antibiotic, and antifungal drugs were established, showing a positive clinical evolution. After 8 months of treatment, the patient's owner moved to a different city, and the animal was seen by other veterinarians, who followed along with the same treatment. However, due to complications and a diminishing quality of life over 4 years of diagnosis, the patient was euthanized.

CONCLUSION

Given the above, mixed osteomyelitis is difficult to treat and can cause losses of life quality resulting death, especially in infections where M. canis is the agent causing the disease. Bacterial osteomyelitis is more frequently reported. But the lack of investigation of microorganisms other than bacteria, such as fungal cases, may imply in underdiagnosed cases. Treatment of osteomyelitis can be difficult considering the difficulties in isolating the pathological agent, resistance to the drug used, prolonged treatment time, and cost.

Treatment of onychomycosis in an era of antifungal resistance: Role for antifungal stewardship and topical antifungal agents

A growing body of literature has marked the emergence and spread of antifungal resistance among species of Trichophyton, the most prevalent cause of toenail and fingernail onychomycosis in the United States and Europe. We review published data on rates of oral antifungal resistance among Trichophyton species; causes of antifungal resistance and methods to counteract it; and in vitro data on the role of topical antifungals in the treatment of onychomycosis. Antifungal resistance among species of Trichophyton against terbinafine and itraconazole-the two most common oral treatments for onychomycosis and other superficial fungal infections caused by dermatophytes-has been detected around the globe. Fungal adaptations, patient characteristics (e.g., immunocompromised status; drug-drug interactions), and empirical diagnostic and treatment patterns may contribute to reduced antifungal efficacy and the development of antifungal resistance. Antifungal stewardship efforts aim to ensure proper antifungal use to limit antifungal resistance and improve clinical outcomes. In the treatment of onychomycosis, critical aspects of antifungal stewardship include proper identification of the fungal infection prior to initiation of treatment and improvements in physician and patient education. Topical ciclopirox, efinaconazole and tavaborole, delivered either alone or in combination with oral antifungals, have demonstrated efficacy in vitro against susceptible and/or resistant isolates of Trichophyton species, with low potential for development of antifungal resistance. Additional real-world long-term data are needed to monitor global rates of antifungal resistance and assess the efficacy of oral and topical antifungals, alone or in combination, in counteracting antifungal resistance in the treatment of onychomycosis.

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.

Dermatophyte infection: from fungal pathogenicity to host immune responses

Dermatophytosis is a common superficial infection caused by dermatophytes, a group of pathogenic keratinophilic fungi. Apart from invasion against skin barrier, host immune responses to dermatophytes could also lead to pathologic inflammation and tissue damage to some extent. Therefore, it is of great help to understand the pathogenesis of dermatophytes, including fungal virulence factors and anti-pathogen immune responses. This review aims to summarize the recent advances in host-fungal interactions, focusing on the mechanisms of anti-fungal immunity and the relationship between immune deficiency and chronic dermatophytosis, in order to facilitate novel diagnostic and therapeutic approaches to improve the outcomes of these patients.

Angioinvasive Trichophyton rubrum associated necrotizing fasciitis in an immunocompromised patient

Angioinvasive dermatophytosis with necrotizing fasciitis can be a rare complication in immunocompromised patients with early surgical debridement, 12 weeks of oral terbinafine, and reduction in immunosuppression being a viable management strategy.

Natural Compounds of Fungal Origin with Antimicrobial Activity-Potential Cosmetics Applications

The phenomenon of drug resistance in micro-organisms necessitates the search for new compounds capable of combating them. Fungi emerge as a promising source of such compounds as they produce a wide range of secondary metabolites with bacteriostatic or fungistatic activity. These compounds can serve as alternatives for commonly used antibiotics. Furthermore, fungi also accumulate compounds with antiviral activity. This review focuses on filamentous fungi and macrofungi as sources of antimicrobial compounds. The article describes both individual isolated compounds and extracts that exhibit antibacterial, antifungal, and antiviral activity. These compounds are produced by the fruiting bodies and mycelium, as well as the biomass of mycelial cultures. Additionally, this review characterizes the chemical compounds extracted from mushrooms used in the realm of cosmetology; specifically, their antimicrobial activity.

Antibiofilm Effect of Lavandula multifida Essential Oil: A New Approach for Chronic Infections

Fungal infections are associated with high morbidity and mortality rates, being highly prevalent in patients with underlying health complications such as chronic lung disease, HIV, cancer, and diabetes mellitus. To mitigate these infections, the development of effective antifungals is imperative, with plants standing out as promising sources of bioactive compounds. In the present study, we focus on the antibiofilm potential of Lavandula multifida essential oil (EO) against dermatophyte strains and Candida albicans. The EO was characterized using GC and GC-MS, and its antifungal effect was assessed on both biofilm formation and disruption. Biofilm mass, extracellular matrix, and viability were quantified using crystal violet, safranin, and XTT assays, respectively, and morphological alterations were confirmed using optical and scanning electron microscopy. L. multifida EO showed very high amounts of carvacrol and was very effective in inhibiting and disrupting fungal biofilms. The EO significantly decreased biofilm mass and viability in all tested fungi. In addition, a reduction in dermatophytes' extracellular matrix was observed, particularly during biofilm formation. Morphological alterations were evident in mature biofilms, with a clear decrease in hypha diameter. These promising results support the use of L. multifida EO in the development of effective plant-based antifungal products.

Surgical management of deep dermatophytosis in a patient with CARD9 deficiency

Deep dermatophytosis is a dermal infection caused by Dermatophytes. It can cause deeper dermal dermatophytosis, Majocchi's granuloma, dermatophytic pseudomycetoma or a widespread infection. CARD9 deficiency is a known risk factor in the Mediterranean region, first reported in 1964 in Morocco. We report a case of 23-year-old man with a scarring alopecia who presented with subcutaneous abscesses topped off with a large ringworm infection. Mycotic analysis revealed a Trichophyton Rubrum deep dermatophytosis. The molecular study revealed a CARD9 mutation confirming dermatophytosis with parotid and lymph nodes involvement. The patient underwent successful drainage surgery of the abscesses alongside medical treatment including antifungal agents and he was discharged after an uneventful postoperative course.

Dual RNA-Sequencing and Liquid Chromatography-Mass Spectrometry Unveil Specific Insights on the Pathogenicity of Trichophyton mentagrophytes Complex

Trichophyton mentagrophytes is increasingly considered to be a public health hazard because it causes the most severe manifestations of dermatophytosis. In this study, we performed a series of studies to determine the pathogenicity of the T. mentagrophytes complex. We show that the T. mentagrophytes complex interacts with keratinocytes through pattern-recognition receptors‒MAPK/noncanonical NF-κB pathways and that the hyphal form of T. mentagrophytes is responsible for the increased inflammatory responses in keratinocytes. Moreover, SN-38 is likely a toxin of T. mentagrophytes that induces apoptosis in keratinocytes both in vivo and in vitro. Our results explain the severe pathogenicity and destructiveness of T. mentagrophytes observed in the clinic and pave the way for designing novel toxin-directed therapies to improve patient outcomes.

Synergistic activity of the combination of falcarindiol and itraconazole in vitro against dermatophytes

Previous studies have shown that natural polyacetylene alcohols, such as falcarindiol (FADOH), have good antifungal effects on plant fungi. While its effect on fungi that infect humans remains to be explored. In our study, checkerboard microdilution, drop-plate assay, and time-growth method were employed to analyze the interactions between FADOH and itraconazole (ITC) in vitro against dermatophytes, including 12 Trichophyton rubrum (T. rubrum), 12 Trichophyton mentagrophytes (T. mentagrophytes), and 6 Microsporum canis (M. canis). The results showed that the combination of FADOH and ITC exhibited synergistic and additive activity against 86.7% of all tested dermatophytes. FADOH had an excellent synergistic effect on ITC against T. rubrum and T. mentagrophytes; the synergistic rates were 66.7% and 58.3%, respectively. On the contrary, FADOH combined with ITC showed poor synergistic inhibitory activity (16.7%) against M. canis. Moreover, the additive rates of these two drugs against T. rubrum, T. mentagrophytes, and M. canis were 25%, 41.7%, and 33.3%, respectively. No antagonistic interactions were observed. The drop-plate assay and time-growth curves confirmed that the combination of FADOH and ITC had a potent synergistic antifungal effect. The in vitro synergistic effect of FADOH and ITC against dermatophytes is reported here for the first time. Our findings suggest the potential use of FADOH as an effective antifungal drug in the combined therapy of dermatophytoses caused especially by T. rubrum and T. mentagrophytes.

DNA metabarcoding-based study on bacteria and fungi associated with house dust mites (Dermatophagoides spp.) in settled house dust

House dust mites (HDMs) including Dermatophagoides spp. are an important cause of respiratory allergies. However, their relationship with microorganisms in house dust has not been fully elucidated. Here, we characterized bacteria and fungi associated with HDMs in house dust samples collected in 107 homes in Korea by using DNA barcode sequencing of bacterial 16S rRNA gene, fungal internal transcribed spacer 2 (ITS2) region, and arthropod cytochrome c oxidase I (COI) gene. Our inter-kingdom co-occurrence network analysis and/or indicator species analysis identified that HDMs were positively related with a xerophilic fungus Wallemia, mycoparasitic fungi such as Cystobasidium, and some human skin-related bacterial and fungal genera, and they were negatively related with the hygrophilous fungus Cephalotrichum. Overall, our study has succeeded in adding novel insights into HDM-related bacteria and fungi in the house dust ecosystem, and in confirming the historically recognized fact that HDMs are associated with xerophilic fungi such as Wallemia. Understanding the microbial ecology in house dust is thought to be important for elucidating the etiology of human diseases including allergies, and our study revealed baseline information of house dust ecology in relation to HDMs. The findings could be useful from a perspective of human health.

The role of the CBM complex in allergic inflammation and disease

The caspase activation and recruitment domain-coiled-coil (CARD-CC) family of proteins-CARD9, CARD10, CARD11, and CARD14-is collectively expressed across nearly all tissues of the body and is a crucial mediator of immunologic signaling as part of the CARD-B-cell lymphoma/leukemia 10-mucosa-associated lymphoid tissue lymphoma translocation protein 1 (CBM) complex. Dysfunction or dysregulation of CBM proteins has been linked to numerous clinical manifestations known as "CBM-opathies." The CBM-opathy spectrum encompasses diseases ranging from mucocutaneous fungal infections and psoriasis to combined immunodeficiency and lymphoproliferative diseases; however, there is accumulating evidence that the CARD-CC family members also contribute to the pathogenesis and progression of allergic inflammation and allergic diseases. Here, we review the 4 CARD-CC paralogs, as well as B-cell lymphoma/leukemia 10 and mucosa-associated lymphoid tissue lymphoma translocation protein 1, and their individual and collective roles in the pathogenesis and progression of allergic inflammation and 4 major allergic diseases (allergic asthma, atopic dermatitis, food allergy, and allergic rhinitis).

Case report: Severe deep ulcer on the left abdomen mimicking mycosis fungoides caused by Trichophyton tonsurans in a patient with novel CARD9 mutation

Dermatophytosis is the most common type of superficial fungal infection caused by dermatophytes. Occasionally, the fungus invades deep into the dermis or other tissues, causing deep dermatophytosis. Deep dermatophytosis is often associated with Caspase Recruitment Domain-containing protein 9 (CARD9) deficiency in patients. Here, we report the first case of deep dermatophytosis with a rare mycosis fungoides manifestation caused by T. tonsurans in a patient with a novel mutation in exon 4 of CARD9. The condition presented with heterozygous K196E mutation, which leads to deficiency of innate and adaptive immune responses in the patient, and caused intractable severe lesions. The patient received treatment with multiple antifungal drugs and was ultimately alleviated by posaconazole. These findings extend the pathogen spectrum of deep dermatophytosis linked with CARD9 deficiency and enriched their phenotypic spectrum.

Dermatology and Skin Conditions for Hand Surgeons

The hand surgeon must be familiar with all aspects of hand pathology, and while faced with dermatological pathology in daily practice, a comprehensive understanding of skin pathology is often lacking. Dermatological pathology may have an impact on the hand surgeon in multiple ways-before surgery (requiring optimization), after surgery, or by mimicking surgical pathology (whereby surgical management may be contraindicated). Adequate knowledge of the basics of dermatology allows for optimal patient care. This review article highlights the common (and the not so common) skin conditions that hand surgeons may encounter in their practice.

Bedside Diagnosis for Disseminated Deep Dermatophytosis: a Case Series Study

Deep cutaneous fungal infections including deep dermatophytosis are responsible for significant morbidity and mortality, especially in immunocompromised patients. Variable and longer turnaround time on tissue culture results delay diagnosis. We sought to seek the fast bedside diagnosis for disseminated deep dermatophytosis by direct microscopy using a blunt scalpel or needle aspiration before biopsy. This is a 6-year retrospective review of patients with a diagnosis of disseminated deep dermatophytosis seen at a single tertiary care institution. Trichophyton rubrum was isolated in four patients, and T. mentagrophyte complex in one patient. All the dermatophyte isolates can grow at 37 °C. Microscopy of purulence sampling from intact nodules demonstrated abundant septate hyphae, and also isolation from purulence was concordance with skin tissue culture. Ultrasound-guided sampling from non-eroded can yield purulence, and direct microscopy of purulence may facilitate rapid diagnosis of deep dermatophytosis and serve to prevent disease progression and dissemination.

Recent concepts in fungal involvement in skin and soft tissue infections

As the at-risk population expands and new antifungal resistance patterns develop, it is critical to understand and recognize cutaneous manifestations of old and emerging fungal diseases.

PURPOSE OF REVIEW

The aim of this review is to provide an overview of the most frequent and emerging deep cutaneous fungal infections following either primary inoculation or secondary spread after haematogenous seeding in disseminated infections in different geographical areas.

RECENT FINDINGS

Fungal skin and soft tissue infections (SSTIs) encompass a variety of pathological conditions based on the site of the infection, route of acquisition of the pathogen, epidemiological setting and the virulence of the fungus in relation to the host. The approach to a patient suspected of having a fungal SSTI is complex and usually poses a major diagnostic challenge. The treatment approach should include attempts at immune reconstitution, targeted antifungal therapy and/or aggressive surgical debridement.

SUMMARY

Fungal SSTIs can be an important cause of morbidity and mortality in both immunocompromised and immunocompetent patients and are being reported with increasing frequency worldwide.

CARD9 Signaling, Inflammation, and Diseases

Caspase-recruitment domain 9 (CARD9) protein is expressed in many cells especially in immune cells, and is critically involved in the function of the innate and adaptive immune systems through extensive interactions between CARD9 and other signaling molecules including NF-κB and MAPK. CARD9-mediated signaling plays a central role in regulating inflammatory responses and oxidative stress through the productions of important cytokines and chemokines. Abnormalities of CARD9 and CARD9 signaling or CARD9 mutations or polymorphism are associated with a variety of pathological conditions including infections, inflammation, and autoimmune disorders. This review focuses on the function of CARD9 and CARD9-mediated signaling pathways, as well as interactions with other important signaling molecules in different cell types and the relations to specific disease conditions including inflammatory diseases, infections, tumorigenesis, and cardiovascular pathologies.

Trichophyton onychomycosis and deep dermatophytosis in a post-heart transplant patient

Deep dermatophytosis is an uncommon fungal infection of the dermis most often seen in the setting of immunocompromise. We report a case of trichophyton deep dermatophytosis in a patient with a history of orthotopic heart transplantation who presented with superficial white onychomycosis and papules and plaques on the legs. This article is protected by copyright. All rights reserved.

Proteome-Wide Identification and Functional Analysis of Lysine Crotonylation in Trichophyton rubrum Conidial and Mycelial Stages

Lysine crotonylation is a newly discovered post-translational modification (PTM) with key roles in various important regulatory pathways. Despite its functional significance, there is limited knowledge about crotonylation in fungi. Trichophyton rubrum is the most common fungal pathogen in human infection and is considered a model organism of dermatophytes and human pathogenic filamentous fungi. In this study, we obtained a proteome-wide crotonylation profile of T. rubrum, leading to the identification of 14,019 crotonylated sites on 3144 proteins. The crotonylated proteins were significantly involved in translation and in various metabolic and biosynthetic processes. Some proteins related to fungal pathogenicity were also found to be targets of crotonylation. In addition, extensive crotonylation was found on histones, suggesting a role in epigenetic regulation. Furthermore, about half of the crotonylated proteins were specific to either the conidial or the mycelial stage, and functional enrichment analysis showed some differences between the two stages. The results suggest that the difference in crotonylation between the two stages is not due to differences in protein abundance. Crosstalk of crotonylation with acetylation, propionylation, and succinylation suggests distinct regulatory roles. This study is the first crotonylation analysis in dermatophytes and human pathogenic filamentous fungi. These results represent a solid foundation for further research on PTM regulatory mechanisms in fungi and should facilitate improved antifungal strategies against these medical important species.

The epidemic of the multiresistant dermatophyte Trichophyton indotineae has reached China

Due to its high degree of natural resistance to terbinafine in vitro and its tendency to spread globally from the Indian subcontinent, the emerging dermatophyte Trichophyton indotineae has become a major concern in dermatology. Herein, we present the first report of T. indotineae from mainland China. The transmission of the fungus to Guizhou Province in central China and eventual host susceptibilities were investigated. We studied 31 strains of the T. mentagrophytes complex from outpatient clinics of our hospital collected during the past 5 years. The set comprised four ITS genotypes, two of which were T. mentagrophytes genotype VIII, now known as Trichophyton indotineae; the earliest isolation in the Guiyang area appeared to date back to 2018. The isolate was derived from an Indian patient, while local Chinese patients had no dermatophytosis caused by this genotype. Reports from around the world indicated that almost all of the globally reported T. indotineae cases originated from the Indian subcontinent and surrounding countries without transmission among native populations, suggesting deviating local conditions or racial differences in immunity against this fungus.

Molecular identification and antifungal susceptibility of 75 clinical isolates of Trichophyton spp. from southern Brazil

BACKGROUND

Dermatophytoses affect more than 20% of the world's population and is caused by filamentous fungi, mainly of the genus Trichophyton. The species identification through microscopic direct examination and culture methods is challenging, with molecular presenting high sensitivity and specificity. Although there are several therapy options for dermatophyte infections, treatment failures and antifungal resistance are growing concerns.

OBJECTIVE

This study aimed to identify clinical isolates of Trichophyton spp. from southern Brazil using molecular methods and determine their in-vitro antifungal susceptibility.

MATERIAL AND METHODS

Seventy-five isolates were identified through sequencing of the ITS region. The exposure to seven antifungals drugs was performed according to protocol M28-A2 of the Clinical and Laboratory Standards Institute (CLSI).

RESULTS

Sixty-one isolates (81%) were identified as T. interdigitale, which differs from the epidemiological data present in the literature. Thirteen isolates were identified as T. rubrum and one as T. tonsurans. Terbinafine was the most effective antifungal, followed by itraconazole and voriconazole, which is in accordance with the results reported in previous studies.

CONCLUSIONS

The use of molecular methods to identify Trichophyton spp. clinical isolates and the performance of susceptibility tests are relevant to epidemiological data, identification of the emergence of antifungal resistance, and to help to translate the in-vitro antifungal susceptibility results into clinical practice.

Invasive Microsporum canis infection as a presenting complaint of late-diagnosed HIV infection

A 43-year-old male barber presented with 1 year history of a painful, itchy plaque on the dorsal hand. Microsporum canis was recovered from pus of the lesion. Serologic testing for human immunodeficiency virus (HIV) antibody was positive, with a CD4⁺ count of 81 cells per cubic millimeter. Invasive cutaneous Microsporum canis infection is uncommon and can be suggestive of HIV infection or other conditions of immunocompromise.

State-of-the-Art Dermatophyte Infections: Epidemiology Aspects, Pathophysiology, and Resistance Mechanisms

The burden of fungal infections is not widely appreciated. Although these infections are responsible for over one million deaths annually, it is estimated that one billion people are affected by severe fungal diseases. Mycoses of nails and skin, primarily caused by fungi known as dermatophytes, are the most common fungal infections. Trichophyton rubrum appears to be the most common causative agent of dermatophytosis, followed by Trichophyton interdigitale. An estimated 25% of the world’s population suffers from dermatomycosis. Although these infections are not lethal, they compromise the quality of life of infected patients. The outcome of antidermatophytic treatments is impaired by various conditions, such as resistance and tolerance of certain dermatophyte strains. The adage “know your enemy” must be the focus of fungal research. There is an urgent need to increase awareness about the significance of these infections with precise epidemiological data and to improve knowledge regarding fungal biology and pathogenesis, with an emphasis on adaptive mechanisms to tackle adverse conditions from host counteractions. This review outlines the current knowledge about dermatophyte infections, with a focus on signaling pathways required for fungal infection establishment and a broad perspective on cellular and molecular factors involved in antifungal resistance and tolerance.

Cutaneous and subcutaneous fungal infections: recent developments on host-fungus interactions

The incidence of skin fungal infections is increasing at an alarming rate worldwide, presenting a major challenge to health professionals. Cutaneous and subcutaneous fungal infections are caused by pathogenic or opportunistic organisms varying from mold, yeasts, to dimorphic fungi. Recently, skin fungal have been increasingly reported and studied, giving rise to crucial breakthroughs in etiology and pathogenesis. This review aims to summarize recent insights into the clinical and etiological characteristics of common skin fungal infections according to different fungal species, as well as remarkable advances in the immune mechanisms. We hope it will be helpful to understand these diverse skin fungal infections, and bring about the latest developments that may facilitate novel diagnostic and therapeutic approaches to improve the outcomes in these patients.