Search Results (151)

Onychomycosis is a therapeutically challenging fungal infection. Systemic antifungals are limited by adverse effects and drug interactions, while topical therapies may fail to achieve therapeutic nail bed concentrations. Nitric oxide (NO), a small, diffusible free radical with broad-spectrum antimicrobial activity, offers a novel approach to overcoming these barriers. We assessed the penetration and subsequent efficacy of a nitric oxide–releasing gel (NORG) in the treatment of onychomycosis. Ex vivo human nail models assessed NORG’s transungual penetration and antifungal activity via colorimetric, immunohistochemical, and microbiological assays. NORG eradicated Trichophyton mentagrophytes completely (0 CFU/g), outperforming terbinafine (3.58 ± 0.2 log₁₀ CFU/g). In an ex vivo infection model, NORG achieved fungal clearance within 14 days, continuing to Day 30 treatment end, with no regrowth during 21 days of incubation post-treatment. Clinical data from patients with onychomycosis who received topical NORG therapy show that NORG penetrated the nail plate and nail bed, as evidenced by s-nitrosothiol accumulation and progressive discoloration. The NORG formulation demonstrates in vitro efficacy; controlled trials are warranted to fully assess clinical efficacy and safety of this NORG formulation in humans, and establish optimal treatment protocols. Full article

This retrospective case series evaluated off-label voriconazole for distal lateral subungual onychomycosis (DLSO) unresponsive to standard therapy. Twenty-nine culture-confirmed patients who had failed terbinafine (250 mg daily × 12 weeks) and itraconazole pulses (200 mg twice daily for 1 week/month × 3) received voriconazole (200 mg twice on day 1, then 200 mg daily for 3–4 months). Assessments occurred at 2, 4, 6–9, and 12 months; the primary endpoint was combined clinical cure (≥90% nail clearance) plus mycological cure (negative KOH and culture) at 12 months. Intention-to-treat included 29 patients; per-protocol included 27 (two did not complete follow-up). In the per-protocol cohort, combined cure was 55.6% (15/27) and mycological cure 74.1% (20/27). Complete clinical cure occurred in 66.7% (18/27); 25.9% (7/27) improved markedly, 3.7% (1/27) mildly, and 3.7% (1/27) showed no improvement. Voriconazole was well tolerated and may be considered for DLSO refractory to terbinafine ± itraconazole. Antifungal stewardship remains essential. Full article

Trichophyton indotineae is an emerging dermatophyte species responsible for recalcitrant and terbinafine-resistant dermatophytosis, raising concerns over diagnostic accuracy and treatment efficacy. This study aimed to improve the identification and resistance profiling of T. indotineae by integrating molecular methods with machine learning-assisted analysis of MALDI-TOF mass spectra. A total of 56 clinical isolates within the Trichophyton mentagrophytes complex were analyzed using ITS and ERG1 gene sequencing, antifungal susceptibility testing, and MALDI-TOF MS profiling. Terbinafine resistance was detected in 23 isolates and correlated with specific ERG1 mutations, including F397L, L393S, F415C, and A448T. While conventional MALDI-TOF MS failed to reliably distinguish T. indotineae from closely related species, unsupervised statistical methods (PCA and hierarchical clustering) revealed distinct spectral groupings. Supervised machine learning algorithms, particularly PLS-DA and SVM, achieved 100% balanced accuracy in species classification using 10-fold cross-validation. Biomarker analysis identified discriminatory spectral peaks for both T. indotineae and T. mentagrophytes (3417.29 m/z and 3423.53 m/z). These results demonstrate that combining MALDI-TOF MS with multivariate analysis and machine learning improves diagnostic resolution and may offer a practical alternative to sequencing in resource-limited settings. This approach could enhance the routine detection of terbinafine-resistant T. indotineae and support more targeted antifungal therapy. Full article

Objectives: Trichophyton indotineae, a dermatophyte closely related to T. interdigitale and T. mentagrophytes, is of growing concern due to its high terbinafine resistance and widespread presence in India. Its emergence in Europe calls for enhanced surveillance. Resistance is linked to mutations in the squalene epoxidase (SQLE) gene. This multicentric national study aimed to evaluate the prevalence, terbinafine susceptibility, and phylogenomics of T. interdigitale/mentagrophytes/indotineae strains in Belgium, with a focus on SQLE substitutions. Methods: Between February 2022 and April 2023, 137 isolates from 16 Belgian labs were analyzed for antifungal susceptibility using the EUCAST E.Def.11.0 method. Whole-genome sequencing (WGS) was performed via Illumina sequencing method. Results: Phylogenomic analysis identified 8 T. indotineae, 91 T. interdigitale, and 38 T. mentagrophytes (including 7 genotype VII strains). Terbinafine resistance (5.1%) was mainly found in T. indotineae (87.5%), always linked to SQLE substitutions. T. interdigitale was fully susceptible. T. mentagrophytes showed mildly elevated MICs, often associated with K276N substitution. Conclusions: Terbinafine-resistant T. indotineae is emerging in Belgium, mostly via imported cases. Continued molecular surveillance and species-specific treatment strategies are essential. Full article

Background/Objectives: Malassezia pachydermatis is a lipophilic yeast frequently associated with otitis externa and dermatological disorders in companion animals. This study aimed to evaluate the antifungal susceptibility of M. pachydermatis isolates from dogs and cats and to investigate the genomic determinants of reduced susceptibility. Methods: Susceptibility testing of 87 clinical isolates was performed using a modified CLSI broth microdilution method in Sabouraud dextrose broth supplemented with 1% Tween 80. The whole genome of ten representative isolates was sequenced and the genetic factors that are involved in drug resistance were investigated. Results: Ketoconazole, itraconazole, and terbinafine exhibited the highest efficacy, while miconazole and clotrimazole showed reduced activity. Whole genome sequencing revealed single nucleotide polymorphisms (SNPs) in genes that play a key role in the ergosterol biosynthesis pathway, particularly in ERG11 and ERG1. While some specific amino acid substitutions (e.g., K446R in ERG11) were found only in isolates with elevated MIC values, no direct correlation with resistance could be unequivocally established. Conclusions: Genomic analyses also uncovered chromosomal mutations and the heterozygosity of certain isolates, suggesting that complex, multifactorial mechanisms may drive the development of drug resistance. These findings highlight the importance of standardized susceptibility testing and further genomic investigations to promote effective antifungal therapy in veterinary medicine. Full article

Background/Objectives: Bullous congenital ichthyosiform erythroderma (BCIE) is an inherited keratinization disorder caused by pathogenic variants in specific genes. Here, we report a pair of half-siblings with BCIE and tinea capitis due to Trichophyton rubrum (T. rubrum) and then review the species of ichthyosis previously reported with T. rubrum infection. Methods: We performed dermatological examination, fungal culture, and genetic analysis using whole-exome sequencing (WES) and blocker displacement amplification (BDA)-based Sanger sequencing. Both patients received oral terbinafine once daily and topical bifonazole gel for tinea capitis. Results: The pair of half-siblings had exhibited generalized scaling and hyperkeratosis since birth. Both siblings subsequently developed scalp pustules and hair loss for several months. Genetic analysis identified a pathogenic variant in the keratin 10 (KRT10) gene, confirming BCIE diagnosis. Additionally, fungal culture revealed T. rubrum infection. The patients responded positively to oral terbinafine antifungal treatment. Conclusions: This case highlights the potential susceptibility of patients with BCIE to fungal infections, warranting clinical vigilance. Furthermore, it demonstrates the utility of the BDA-based mutation detection method for diagnosing BCIE, suggesting its promise for advancing personalized diagnosis and management in hereditary skin diseases. Full article

Onychomycosis is a prevalent and clinically relevant complication among individuals with diabetes. It is associated with an elevated risk of secondary fungal and bacterial infections, foot ulceration, and, in advanced cases, amputation. Factors contributing to the increased prevalence of onychomycosis in this population include age, peripheral vascular disease, poor glycemic control, neuropathy, suboptimal foot hygiene, and nail trauma. While dermatophytes are the most common pathogens, diabetic patients are more prone to mixed infections involving Candida species with varying antifungal susceptibility profiles, necessitating accurate identification to guide therapy. Prompt diagnosis and early intervention are important to prevent complications. Systemic antifungals such as terbinafine and itraconazole are considered first-line therapies, particularly for moderate to severe onychomycosis. However, drug interactions, renal, hepatic, and metabolic comorbidities may necessitate individualized treatment plans. For patients with mild to moderate disease, or contraindications to oral therapy, topical agents such as efinaconazole or tavaborole offer viable alternatives. Adjunctive measures, including education on foot hygiene, prompt treatment of tinea pedis, and environmental sanitization, are important in preventing recurrence and reinfection. This review summarizes the epidemiology, diagnosis, and treatment considerations for onychomycosis in diabetic patients, emphasizing the need for individualized care to improve outcomes in this high-risk population. Full article

Dermatophytes are keratinophilic fungi that cause a wide range of superficial infections in humans and animals. The Trichophyton mentagrophytes species complex is one of the most clinically important groups due to its broad host range, widespread distribution, and increasing involvement in antifungal-resistant infections. Here, we described the epidemiology of T. mentagrophytes over a period of 4 years detected in the northeastern part of Italy and provided the genomic characterization of clinical isolates. ITS sequence analysis revealed that among the 13 strains studied, 11 belonged to the T. mentagrophytes complex. In detail, nine were classified as genotype I/II and two as genotype VII. Analysis of the SQLE gene revealed that nine strains harbored a wild-type gene, while two carried a Lys276Asn mutation. Genomic analysis was performed on three clinical T. mentagrophytes strains that belonged to genotype I/II, revealing the presence of different virulence factors including MEP-1, MEP-2, MEP-3, and MEP-5. Phylogenetic analysis based on core-genome SNPs demonstrated that the two genomes included in this study were clonally related to a T. mentagrophytes strain isolated in China in 2024. In conclusion, our study highlights the importance of genomic characterization in order to trace the epidemiology of dermatophytes worldwide and to characterize emerging strains. Full article

Trichophyton indotineae is emerging globally from its origin in India, presenting with a terbinafine resistance and causing significant clinical burden. We report herein the first four confirmed cases of T. indotineae dermatophytoses in Malaysia, which were diagnosed based on the microscopic examination of skin scrapings using potassium hydroxide (KOH) wet mount, followed by confirmation via culture and Internal Transcribed Spacer (ITS1) sequencing. In contrast to conventional Trichophyton infections, T. indotineae dermatophytoses demonstrate extensive cutaneous involvement and marked inflammation with erythematous lesions. All cases exhibited a chronic course lasting more than three months, with evidence of person-to-person transmission. Although one patient reported a travel to Singapore, three had no recent travel history, suggesting possible local transmission. The isolates produced characteristic white, cottony colonies with radial mycelial growth on Mycosel agar after incubation at 30 °C for four days. Three patients responded well to oral itraconazole (200 mg daily), with reduced inflammation and erythematous lesions observed two weeks after treatment initiation. The occurrence of T. indotineae particularly among patients without a travel history, suggests a potential endemic establishment. This fungal pathogen warrants consideration in cases of extensive or recalcitrant dermatophytoses. Further investigations into the diagnostic methods, antifungal susceptibility profiles, and epidemiological risk factors of Malaysian strains are warranted to enhance clinical management and inform public health interventions. Full article

Background: Trichophyton indotineae, a new emerging pathogen according to the WHO, is known to cause severe forms of tinea. Given that traditional identification methods rely on morphological characteristics, and the morphological distinctions among T. indotineae, T. mentagrophytes, and T. interdigitale are minimal, the adoption of alternative diagnostic techniques, such as RT-PCR or gene sequencing, has become critically important to prevent misidentification. The purpose of this study was firstly to analyze the local epidemiology of dermatophytes isolated and secondly to investigate the presence of T. indotineae among the isolated strains. Methods: Between January 2021 and June 2024, 1096 samples of skin adnexa were analysed. The isolated strains belonging to the genus Trichophyton were submitted to molecular identification by ITS sequencing, and T. indotineae strains were subjected to squalene epoxidase (SQLE) sequencing analysis. Results: Trichophyton rubrum and Trichophyton interdigitale appear to be the most prevalent pathogenic species. Molecular identification reveals four T. indotineae strains (4/87; 4.61%) from Asian patients, which were also characterized by gene mutations associated with terbinafine resistance. Conclusions: This study has made it clear that there is a need to implement basic mycological diagnostics with molecular methods to avoid misidentifications, ensure the correct identification, and evaluate the presence of mutations associated with antifungal drug resistance. Full article

Background: Skin cancer has become a global health issue because of increasing exposure to environmental contaminants and UV radiation. Terbinafine hydrochloride (TRB), a broad-spectrum antifungal medication, has demonstrated notable anti-tumor properties in previous studies; however, its repurposing for skin cancer therapy remains underexplored. Objective: This study reports for the first time, the development of a new delivery system: a nanoemulsion (NE)–foam hybrid system, i.e., “nanoemulfoam” (NEF), designed to enhance the topical TRB delivery to the skin. The study applied this new hybrid system on TRB for managing skin cancer. Method: The TRB-loaded NEF was produced by loading TRB into a liquid NE. then this was incorporated into a liquid foam base and actuated into foam using a non-propellant mechanism. The NE was developed utilizing peppermint oil as the oil phase and Tween-20/ethanol as the surfactant/co-surfactant combination (Smix). The formulation underwent optimization using the D-optimal design that enabled the simultaneous evaluation of the impact of oil concentration and Tween 20 concentration in the Smix on the particle size (PS), zeta potential (ZP), and dissolution efficiency percent (DE%). Results: The optimal NE formula displayed a small PS of 186.60 ± 2.84 nm, ZP of −13.90 ± 0.99 mV, and DE% of 68.50 ± 1.78% (mean ± SD, n = 3). After incorporation into the foam system, the produced TRB-loaded NEF demonstrated a 7.43-fold increase in the drug transdermal flux in comparison with plain drug foam (p < 0.05). The TRB-loaded NEF showed no signs of inflammation or irritation when applied to abdominal rabbit skin, indicating its safety. The optimum formula exhibited a statistically significant 10-fold increase in cytotoxicity against A-431 skin cancer cells compared to TRB alone, along with a 1.54-fold increase in apoptosis (p < 0.05). Molecular docking studies targeting CDK2, a key regulator of cell proliferation and a known TRB target, revealed that TRB displayed highly favorable binding scores compared to the reference drug. Conclusions: The TRB-loaded NEF represents a promising nanotechnology-based approach for the topical treatment of skin cancer, supporting further investigation toward clinical translation. Full article

Cytochrome P450 (CYP) enzymes are membrane-bound hemoproteins crucial for drug and xenobiotic metabolism. While more than 50 CYPs have been identified in humans, the isoforms from CYP1, 2, and 3 families contribute to the metabolism of about 80% of clinically approved drugs. To evaluate the effects of environmental chemicals on the activities of these important CYP enzyme families, we screened the Tox21 10K compound library to identify chemicals that inhibit CYP1A2, 2C9, 2C19, 2D6, and 3A4 enzymes. The data obtained from these five screenings were analyzed to reveal the structural classes responsible for inhibiting multiple and/or selective CYPs. Some known structural compound classes exhibiting pan-CYP inhibition, such as azole fungicides, along with established clinical inhibitors of CYPs, including erythromycin and verapamil inhibiting CYP3A4 and paroxetine and terbinafine inhibiting CYP2D6, were all confirmed in the current study. In addition, some selective CYP inhibitors, previously unknown but with potent activity (IC₅₀ values < 1 µM), were identified. Examples included yohimbine, an indole alkaloid, and loteprednol, a corticosteroid, which showed inhibitory activity in CYP2D6 and 3A4 assays, respectively. These findings suggest that assessment of a candidate compound’s impact on CYP function may allow pre-emptive mitigation of potential adverse reactions and toxicity during drug development or toxicological characterization of environmental chemicals. Full article

Background/Objectives: Terbinafine has been the gold standard for the management of superficial fungal infections. The etiological agent generally is Trichophyton rubrum (T. rubrum); however, there has been increased reporting of a new terbinafine-resistant strain of the T. mentagrophytes complex (T. mentagrophytes ITS genotype VIII otherwise known as T. indotineae). Here, we review the epidemiology, clinical features, diagnosis, and treatment of T. rubrum and T. indotineae infections. Methods: We conducted a systematic literature search using PubMed, Embase (Ovid), and Web of Science, resulting in 83 qualified studies with data summarized for clinical features, antifungal susceptibility, and terbinafine resistance mechanisms and mutations. Results: Dermatophytosis is most commonly caused by T. rubrum; however, in certain parts of the world, especially in the Indian subcontinent, T. indotineae infections have been reported more frequently. The majority of T. rubrum isolates remain susceptible to terbinafine (over 60% of isolates show MIC₅₀ and MIC₉₀ < 0.5 µg/mL). In contrast, for T. indotineae, 30% of isolates exhibit MIC₅₀ ≥ 0.5 µg/mL and 80% exhibit MIC₉₀ ≥ 0.5 µg/mL. Frequently detected squalene epoxidase (SQLE) mutations in T. rubrum are Phe397Leu/Ile (41.6%) and Leu393Phe (20.8%); in T. indotineae, these include Phe397Leu (33.0%) and Ala448Thr (24.5%). Other potential terbinafine resistance mechanisms in T. rubrum and T. indotineae are discussed. Conclusions: T. rubrum generally remain susceptible in vitro to terbinafine in contrast to T. indotineae. The essential components of an effective antifungal stewardship emphasize accurate clinical and laboratory diagnosis, susceptibility testing, and appropriate antifungal therapy selection with a multidisciplinary approach. Full article

Background: Trichophyton indotineae terbinafine-resistant infections are emerging in healthy individuals. Luliconazole, an imidazole antifungal that is effective against skin infections, faces challenges due to low water solubility and poor skin penetration. This study aimed to formulate a luliconazole-loaded nanostructured lipid-carrier (NLC) gel in a Carbopol-based system to enhance drug absorption and efficacy in a guinea pig model of dermatophytosis. Methods: Luliconazole-loaded nanostructured lipid carriers (NLCs) were prepared using a solvent evaporation method and gel formulation. Skin absorption and retention were assessed via Franz diffusion cells. The antifungal efficacy was tested against T. indotineae in thirty guinea pigs with induced tinea corporis, divided into five treatment groups. Mycological, clinical, and histopathological evaluations were conducted, along with skin irritation studies for safety. Results: LCZ-NLC demonstrated significantly better skin penetration than simple luliconazole gel, with cumulative drug penetration of 71.8 ± 3.7 μg/cm² versus 50.9 ± 4.2 μg/cm² after 24 h. Both formulations achieved complete infection resolution after 21 and 28 days, with reduced inflammation and no local irritations. On day 21, the LCZ-NLC 1% gel significantly reduced lesion scores and mycological evidence of infection compared to the terbinafine-treated groups, untreated controls, and NLC-gel-treated group (p < 0.05). Histopathological analysis indicated a reduction in both epidermal thickening and fungal burden in the models that received treatment with the LCZ-NLC 1% gel. Conclusions: Luliconazole-loaded lipid carriers enhance drug absorption and efficacy, suggesting shorter treatment durations and improved patient outcomes for resistant fungal infections. However, further studies are warranted to correlate these findings with clinical outcomes. Full article

In recent decades, despite being well-known, dermatophytosis has seen a resurgence and an increase in the incidence of infections, with dermatophytes such as Trichophyton rubrum being the most common agents. Dermatophytosis pathogenesis involves complex interactions between the host, agent, and environment. In many cases, dermatophytosis can be mistaken for other pathologies, which leads to incorrect therapies and the consequent non-recovery of the patient. In this paper, we describe five previously undiagnosed cases of diffuse T. rubrum dermatophytosis because they represent the clinical manifestations that affect several sites at the same time and that, if not properly diagnosed and treated, can lead to severe, widespread, chronic, and difficult-to-treat dermatophytosis. This case series of five instances of misdiagnosed T. rubrum dermatophytosis was later accurately diagnosed and successfully treated with systemic terbinafine hydrochloride 250 mg/die for at least four weeks up to twelve or sixteen, and topical azoles (sertaconazole nitrate 2%) as well. This case series highlights the need to make an accurate diagnosis and avoid misidentifications while offering insightful information about the clinical presentation and treatment of these illnesses. Full article