Major challenges in dermatophytosis treatment: current options and future visions

Antimicrobial properties of WCO-based composites enriched with hops and curly sorrel for green building solutions

Modern production of vegetable oils has reached impressive levels, and the ever-growing quantities of waste cooking oil (WCO) provide a local source of raw materials for innovative materials. The WCO composite production process involves a series of reactions, including polymerisation, esterification, and transesterification, which lead to the hardening of composite materials. In light of the growing problem of bacterial and fungal diseases, materials with high strength properties and biocidal properties are being sought. Fungal infections of the skin are a widespread problem, and the number of cases is steadily increasing. This article presents a study of the antibacterial potential of WCO-based composites enriched with hops or sorrel root in the context of their application in the construction industry. The compressive and flexural strength of the oil composites, their absorbability and hydrophobicity, and their effects on Gram-positive (S. aureus and S. epidermidis) and Gram-negative (E. coli and P. aeruginosa) bacteria and fungi (A. niger, P. anomala) were investigated. Maximum split tensile strength (4.3 MPa) and flexural strength (5.1 MPa) were recorded for oil-hop composites. Oil composites enriched with curly sorrel and hops showed antibacterial activity against S. aureus at 27% and 25%. High biocidal activity (up to 70%) was recorded against E. coli and against S. epidermidis (up to 99%) due to the action of composites with curly sorrel. The antifungal activities of composites with hops was 15% and 19% for P. anomala and A. niger, respectively, while with curly sorrel they were 42% and 30%.

Assessing the Efficacy of Berberine Hydrochloride-loaded Transethosomal Gel System in Treating Dermatophytosis Caused by Trichophyton rubrum in ex-vivo, in-vitro and in-vivo Models

BACKGROUND

Dermatophytosis is the most common dermatological disorder worldwide. Many drugs are available in the market for the treatment of dermatophytosis, but they have had limited success due to the stratum corneum barrier, antifungal resistance, drug permeation, drug retention in skin layers, etc. Thus, there is a constant need for new topical compounds that are effective against dermatophytosis. Berberine-hydrochloride is an attractive candidate to become an antifungal drug, and by using nanotechnology, it achieves deeper penetration in skin layers with enhanced permeability through the stratum corneum.

METHODS

In this study, we developed an oleic acid-containing berberine-hydrochloride-loaded transethosomal gel for effective treatment of dermatophytosis by Trichophyton rubrum. Berberine- hydrochloride-loaded transethosomal gels were fabricated using the hot homogenization method, followed by the incorporation of transethosomes into the gel-based system using carbopol 934. Transethosomal gel was characterized by physicochemical properties, in vitro drug release, ex-vivo permeation studies, CLSM visualization, antifungal activity, histopathological evaluation, and dermatokinetic study.

RESULTS

Berberine-hydrochloride-loaded transethosomes seemed to be spherical and found in a range between 200-300 nm. Berberine-hydrochloride-loaded transethosomal gel formulation also exhibited controlled ex-vivo permeation of berberine-hydrochloride over 24 hr through excised rat skin, and CLSM confirmed deeper penetration into skin layers. The in vivo study revealed that transethosomal gel had a healing effect on the skin of Wistar rats infected with Trichophyton rubrum and was better than luliconazole cream. The histopathological evaluation confirmed its safety, and the dermatokinetic study showed transethosomal gel superiority over marketed cream.

CONCLUSION

Therefore, the incorporation of berberine hydrochloride-loaded transethosomal nanosystems into the gel has the potential to enhance antifungal activity and permeation through transdermal drug delivery.

Detection of Squalene Epoxidase Mutations in United States Patients with Onychomycosis: Implications for Management

Resistance to oral terbinafine, the most commonly used antifungal to treat dermatophytosis and onychomycosis worldwide, is being increasingly reported. In this study, we aimed to investigate the species distribution and prevalence of squalene epoxidase mutations among toenail dermatophyte isolates. Samples from 15,683 patients suspected of onychomycosis visiting the offices of dermatologists and podiatrists in the United States were analyzed. Clinical information was reviewed, and dermatophyte species with or without squalene epoxidase mutations were detected using multiplex real-time PCRs. The frequency of dermatophytes was 37.6%; of isolates belonging to the Trichophyton genus, 88.3% were the T. rubrum complex, and 11.2% were the T. mentagrophytes complex. Individuals aged >70 years exhibited higher infection rates for the T. mentagrophytes complex. The overall mutation rate among Trichophyton spp. was 3.7%, with a higher mutation rate detected in the T. mentagrophytes complex (4.3 vs. 3.6%). Commonly detected mutations were T1189C/Phe397Leu (34.5%), T1306C/Phe415Ser (16.0%), and C1191A/Phe397Leu (11.0%). Squalene epoxidase gene mutations associated with decreased terbinafine susceptibility have been identified in United States patients with toenail onychomycosis. Physicians should be aware of the risk factors for resistance development and engage in antifungal stewardship practices such as directed diagnosis and treatment of dermatophytosis and onychomycosis.

Superficial Dermatophytosis across the World's Populations: Potential Benefits from Nanocarrier-Based Therapies and Rising Challenges

The most prevalent infection in the world is dermatophytosis, which is a major issue with high recurrence and can affect the entire body including the skin, hair, and nails. The major goal of this Review is to acquire knowledge about cutting-edge approaches for treating dermatophytosis efficiently by adding antifungals to formulations based on nanocarriers in order to overcome the shortcomings of standard treatment methods. Updates on nanosystems and research developments on animal and clinical investigations are also presented. Along with the currently licensed formulations, the investigation also emphasizes novel therapies and existing therapeutic alternatives that can be used to control dermatophytosis. The Review also summarizes recent developments on the prevalence, management approaches, and disadvantages of standard dosage types. There are a number of therapeutic strategies for the treatment of dermatophytosis that have good clinical cure rates but also drawbacks such as antifungal drug resistance and unfavorable side effects. To improve therapeutic activity and get around the drawbacks of the traditional therapy approaches for dermatophytosis, efforts have been described in recent years to combine several antifungal drugs into new carriers. These formulations have been successful in providing improved antifungal activity, longer drug retention, improved effectiveness, higher skin penetration, and sustained drug release.

Transcriptome Analysis of Co-Cultures of THP-1 Human Macrophages with Inactivated Germinated Trichophyton rubrum Conidia

Although most mycoses are superficial, the dermatophyte Trichophyton rubrum can cause systemic infections in patients with a weakened immune system, resulting in serious and deep lesions. The aim of this study was to analyze the transcriptome of a human monocyte/macrophage cell line (THP-1) co-cultured with inactivated germinated T. rubrum conidia (IGC) in order to characterize deep infection. Analysis of macrophage viability by lactate dehydrogenase quantification showed the activation of the immune system after 24 h of contact with live germinated T. rubrum conidia (LGC). After standardization of the co-culture conditions, the release of the interleukins TNF-α, IL-8, and IL-12 was quantified. The greater release of IL-12 was observed during co-culturing of THP-1 with IGC, while there was no change in the other cytokines. Next-generation sequencing of the response to T. rubrum IGC identified the modulation of 83 genes; of these, 65 were induced and 18 were repressed. The categorization of the modulated genes showed their involvement in signal transduction, cell communication, and immune response pathways. In total, 16 genes were selected for validation and Pearson's correlation coefficient was 0.98, indicating a high correlation between RNA-seq and qPCR. Modulation of the expression of all genes was similar for LGC and IGC co-culture; however, the fold-change values were higher for LGC. Due to the high expression of the IL-32 gene in RNA-seq, we quantified this interleukin and observed an increased release in co-culture with T. rubrum. In conclusion, the macrophages-T. rubrum co-culture model revealed the ability of these cells to modulate the immune response, as demonstrated by the release of proinflammatory cytokines and the RNA-seq gene expression profile. The results obtained permit to identify possible molecular targets that are modulated in macrophages and that could be explored in antifungal therapies involving the activation of the immune system.

Clinical Manifestations of Human Exposure to Fungi

Biological particles, along with inorganic gaseous and particulate pollutants, constitute an ever-present component of the atmosphere and surfaces. Among these particles are fungal species colonizing almost all ecosystems, including the human body. Although inoffensive to most people, fungi can be responsible for several health problems, such as allergic fungal diseases and fungal infections. Worldwide fungal disease incidence is increasing, with new emerging fungal diseases appearing yearly. Reasons for this increase are the expansion of life expectancy, the number of immunocompromised patients (immunosuppressive treatments for transplantation, autoimmune diseases, and immunodeficiency diseases), the number of uncontrolled underlying conditions (e.g., diabetes mellitus), and the misusage of medication (e.g., corticosteroids and broad-spectrum antibiotics). Managing fungal diseases is challenging; only four classes of antifungal drugs are available, resistance to these drugs is increasing, and no vaccines have been approved. The present work reviews the implications of fungal particles in human health from allergic diseases (i.e., allergic bronchopulmonary aspergillosis, severe asthma with fungal sensitization, thunderstorm asthma, allergic fungal rhinosinusitis, and occupational lung diseases) to infections (i.e., superficial, subcutaneous, and systemic infections). Topics such as the etiological agent, risk factors, clinical manifestations, diagnosis, and treatment will be revised to improve the knowledge of this growing health concern.

Development, preparation, and evaluation of a novel non-adjuvanted polyvalent dermatophytes vaccine

Ringworm is a worldwide distributed contagious disease infecting both man and animals that constitute an economic, zoonotic, and health problem concern all over the world. During the last decade, attention has been directed to vaccination as an ideal approach to the control of such diseases. In the present study, non-adjuvanted polyvalent vaccines were prepared from locally isolated hot and virulent dermatophyte species, namely Trichophyton verrucosum (T. verrucosum), Trichophyton mentagrophytes (T. mentagrophytes), and Microsporum canis (M. canis) were immunologically evaluated. The prepared vaccine evaluation was focused on the aspects of immunogenicity and protective efficacy using guinea pigs. Both in its living or inactivated forms, the vaccine-induced significant humoral and cell-mediated immune responses and achieve proper protection of guinea pigs against challenging infections with homologous and heterologous dermatophyte strains. On the other hand, investigations on dermatophyte exo-keratinases showed that it was better produced and more expressed in a mineral-based medium containing pure keratin (3 g/L) than in the same medium with human hair supplementation (2.6 g/L). The maximum dermatophyte productivity of exo-keratinases was found to be between 18 and 21 days post-incubation. Using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), two fractions with molecular weights of 40 kDa (fraction I) and 28 kDa (fraction II) have been identified in the culture filtrate of the three involved dermatophyte species. Both fractions demonstrated keratinolytic activity. The specific activity of the isolated keratinases (number of Keratinase units (KU)/mg protein) was stronger in fraction I, where it reached 18.75, 15.38, and 14 KU/mg protein as compared to 12.9, 8.74, and 12 KU/mg protein in fraction II of T. verrucosum, T. mentagrophytes, and M. canis, respectively. The dermatophyte exo-keratinases proved to be immunogenic as they stimulated high keratinase-specific antibody titers and induced strong delayed skin hypersensitivity reactions in vaccinated animals. Anti-keratinase-specific IgG was detected in sera of guinea pigs immunized with the inactivated or living polyvalent dermatophyte vaccines by a homemade enzyme-linked immunosorbent assay (ELISA) using dermatophyte exo-keratinases as coating antigen. The intradermal injection of dermatophyte exo-keratinases induced specific delayed skin reactions in guinea pigs immunized with the inactivated or the living polyvalent dermatophyte vaccines. The intradermal injection of dermatophyte exo-keratinases in the control non-sensitized guinea pigs was associated with itching, swelling, and bloody scar formation, however, no skin indurations were formed. The development of those post-exo-keratinases injection reactions in the control non-sensitized apparently healthy guinea pigs group, suggests an exo-keratinases possible role in the pathogenesis of dermatophytosis.

Isoflavaspidic Acid PB Extracted from Dryopteris fragrans (L.) Schott Inhibits Trichophyton rubrum Growth via Membrane Permeability Alternation and Ergosterol Biosynthesis Disruption

Isoflavaspidic acid PB (PB), a phloroglucinol derivative extracted from aerial parts of Dryopteris fragrans (L.) Schott, had antifungal activity against several dermatophytes. This study was aimed at exploring the antifungal mechanism of PB against Trichophyton rubrum (T. rubrum). The effectiveness of PB in inhibiting T. rubrum growth was detected by time-kill kinetics study and fungal biomass determination. Studies on the mechanism of action were investigated using scanning electron microscopy (SEM), transmission electron microscopy (TEM), sorbitol and ergosterol assay, nucleotide leakage measurement, and UPLC-based test and enzyme-linked immunosorbent assay. Fungicidal activity of PB was concentration- and time-dependent at 2 × MIC (MIC: 20 μg/mL) after 36 h. The total biomass of T. rubrum was reduced by 64.17%, 77.65%, and 84.71% in the presence of PB at 0.5 × MIC, 1 × MIC, and 2 × MIC, respectively. SEM analysis showed that PB changed mycelial morphology, such as shrinking, twisting, collapsing, and even flattening. TEM images of treated cells exhibited abnormal distributions of polysaccharide particles, plasmolysis, and cytoplasmic content degradation accompanied by plasmalemma disruption. There were no changes in the MIC of PB in the presence of sorbitol. However, the MIC values of PB were increased by 4-fold with exogenous ergosterol. At 4 h and 8 h, PB increased nucleotide leakage. Besides, ergosterol content in T. rubrum membrane treated with PB at 0.5 × MIC, 1 × MIC, and 2 × MIC was decreased by 9.58%, 15.31%, and 76.24%, respectively. There was a dose-dependent decrease in the squalene epoxidase (SE) activity. And the reduction in the sterol 14α-demethylase P450 (CYP51) activity was achieved after PB treatments at 1 × MIC and 2 × MIC. These results suggest that PB displays nonspecific action on the cell wall. The membrane damaging effects of PB were attributed to binding with ergosterol to increase membrane permeability and interfering ergosterol biosynthesis involved with the reduction of SE and CYP51 activities. Further study is needed to develop PB as a natural antifungal candidate for clinical use.

Antifungal and antibiofilm activities of bee venom loaded on chitosan nanoparticles: a novel approach for combating fungal human pathogens

The prevalence of opportunistic human fungal pathogens is increasing worldwide, and antimicrobial resistance is one of the greatest medical challenges the world faces. Therefore, this study aimed to develop a novel agent to control fungal pathogens. The honeybee products (honey, royal jelly, propolis, bee bread, and bee venom) were screened against unicellular fungal (UCF) pathogens (Cryptococcus neoformans, Kodamaea ohmeri, and Candida albicans) and the bee venom was only exhibited an inhibitory effect against them. The protein contents of crude bee venom were separated using the gel filtration technique into eight fractions which were visualized on sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS–PAGE) to confirm the presence of five bands with molecular weights of 65, 43, 21, 15, and 3 KDa. Bee venom (BV) of Apis mellifera loaded chitosan nanoparticles were prepared by the ionotropic gelation method. The encapsulation efficiency%, average size, zeta potentials, and surface appearance by Transmission electron microscope (TEM) were evaluated for the prepared nanoparticles. The minimum inhibitory concentration (MIC) of crude BV and BV loaded chitosan nanoparticles (BV-CNPs) was evaluated against the offer mentioned UCF where the MIC values of crude BV were 6.25, 3.12 & 6.25 while MIC values in the case of BV-CNPs were decreased to 3.12, 3.12 & 1.56 mg/ml against C. neoformans, K. ohmeri and C. albicans, respectively. Also, the results showed that BV-CNPs suppressed the biofilm formation as well as yeast to hyphal transition formed by the examined UCF. These results revealed that BV-CNPs are a promising natural compound for fungal pathogens treatment.