Nondermatophyte Molds Research Articles

Onychomycosis in the US Pediatric Population-AnEmphasis on Fusarium Onychomycosis.

Onychomycosis is a common nail disease that is often difficult to treat with a high risk of recurrence. To update our current understanding of the etiologic profile in pediatric patients with onychomycosis utilizing molecular diagnosis by polymerase chain reaction (PCR) combined with histopathologic examination. Records of 19,770 unique pediatric patients were retrieved from a single diagnostic laboratory in the United States spanning over a 9-year period (March 2015 to April 2024). This cohort represents patients clinically suspected of onychomycosis seen by dermatologists and podiatrists. Dermatophytes, nondermatophyte molds (NDMs), and yeasts were identified by multiplex real-time PCR corroborated by the demonstration of fungal invasion on histopathology. An average of 37.0% of all patients sampled were mycology-confirmed to have onychomycosis. Most patients were between ages 11 and 16 years, and the rate of mycologically confirmed onychomycosis was significantly higher among the 6- to 8-year (47.2%) and 9- to 11-year (42.7%) age groups compared to the 0- to 5-year (33.1%), 12- to 14-year (33.2%), and 15- to 17-year (36.7%) age groups. The majority of infections were caused dermatophytes (74.7%) followed by NDMs (17.4%). The Trichophyton rubrum complex represents the dominant pathogen with higher detection rates in the 6- to 11-year-olds. Fusarium was the most commonly isolated NDM with an increasing prevalence with age. Elementary school-aged children have a higher risk of contracting onychomycosis which may be attributed to the onset of hyperhidrosis at puberty, use of occlusive footwear, nail unit trauma, and walking barefoot. Fusarium onychomycosis may be more prevalent than expected, and this may merit consideration of management strategies.

Prevalence, aetiology and factors associated with onychomycosis among patients with diabetes at a Tertiary Care Centre in Galle, Sri Lanka

Introduction: Epidemiological data of onychomycosis, a common fungal nail infection found in diabetics, is scarce in Sri Lanka. Objective: To determine the prevalence, aetiological agents and associated factors of onychomycosis among patients with clinically suspected diabetics in southern Sri Lanka. Method: A cross-sectional study was done using a sample of 97 diabetic patients suspected of having onychomycosis in a tertiary diabetes care centre in Galle. Nail clippings were collected, and microscopic and cultural examinations were done. Both microscopic and culture positive cases were considered as having onychomycosis. Results: The prevalence of onychomycosis was 18.6% (95% CI: 11.38%, 27.73%). Non-dermatophyte moulds (NDMs) (55.7%) and yeast (30.9%) were the dominant aetiological agents. The leading pathogens found among NDMs were Aspergillus sp. (35.1%) and Fusarium sp. (1.4%) and Candida albicans (8.2%). Aspergillus niger (20.6%) was the most frequently isolated Aspergillus sp. in the NDMs. Frequent use of detergents and walking bare foot were the significant risk factors of onychomycosis. Only 15.5% of the participants were aware of onychomycosis. Conclusion: Onychomycosis is prevalent to a considerable level among diabetics. Regular dermatological investigations of nails and health education are needed to combat the disease. Large scale research is warranted to confirm these assertions.

Fungal Keratitis in Northwestern Spain: Epidemiology, Risk Factors and Outcomes.

To review the clinical features, risk factors, microbiological profile, and treatment regimens of fungal keratitis in Galicia, a region in Northwestern Spain with temperate humid weather. A retrospective case series was employed, including patients with fungal keratitis from nine hospitals within the region of Galicia, Spain, between 2010 and 2020. Data obtained from clinical records were analysed. Out of 654 cases of infectious keratitis, 77 cases (9.9%) were identified as fungal keratitis. The median age of affected patients was 68.0 years, with a higher incidence in rural areas (62.3%). Candida spp. infections were the most frequent type (55.8%) and were associated with a higher median age than were the non-dermatophyte mould infections. The primary risk factors included steroid eyedrop use (29.9%), recent keratoplasty (18.2%), ocular trauma (19.5%), and contact with vegetable matter (11.7%). Most ulcers displayed stromal involvement, and 37.7% presented corneal thinning. The median duration of infection was longer in fungal than in bacterial keratitis, and surgical intervention was required in 48.1% of cases. Fungal keratitis, mainly involving Candida spp., accounted for 9.9% of microbial keratitis cases in Galicia, Spain, with significant risk factors being topical steroid use, ocular trauma, and contact with vegetable matter. Delayed diagnosis often resulted in poor outcomes, highlighting the need for early detection through awareness and new technologies to improve prognosis.

Prevalence of onychomycosis among psoriasis patients: a clinico-mycological and dermoscopic comparative cross sectional study

Onychomycosis, a nail infection caused by dermatophytes, yeast, and molds makes up roughly half of all onychopathies and is the most prevalent nail condition in the world. Clinically, nail psoriasis and onychomycosis can frequently be difficult to distinguish from one another. To assess the prevalence of onychomycosis in patients with psoriasis. Fifty patients with psoriasis associated with nail disease were included in this study. After taking clinical history, nail samples were gathered for dermoscopic inspection, culture, direct microscopy with 20% KOH solution, and nail clipping with PAS stain. Of the 50 patients recruited, 43 were males and 7 were females, with mean age 6–71 years (mean ± SD 44.06 ± 16.2). Eleven patients (22%) tested positive for onychomycosis. Dermatophytes were isolated from 2% of patients, yeast from 14% of patients, and non-dermatophytic mold from 38% of patients. Histopathological results revealed fungal hyphae and spores in 18% of patients. The most prevalent dermoscopic sign in psoriatic patients with onychomycosis was spikes (81.8%) with statistical significance (P-value < 0.001), while nail pitting was the most prevalent dermoscopic feature in nail psoriasis. This study lays the way for an accurate diagnosis of nail lesions by highlighting the significance of cooperation between mycology, histology, and dermoscopy in the diagnosis of onychomycosis in patients with nail psoriasis.

Treatments for Onychomycosis: A Bibliometric Analysis

Introduction: Oral antifungals were the earliest treatments to receive approval for the management of onychomycosis and have a long-standing record to support their efficacy. Topical antifungals and device-based treatments have been explored and some implemented in more recent years as alternatives to traditional oral antifungals. The present bibliometric analysis summarizes trends in publication frequency for onychomycosis treatment modalities over time and characterizes their body of literature in terms of types of studies available and relative level of evidence. Methods: A comprehensive literature search was performed using Web of Science and SCOPUS databases. Results: Covering all publications from 1970 to present day, our search identified oral therapeutics n = 295 articles (n = 63 randomized control trials [RCTs]), topical therapeutics n = 358 articles (n = 72 RCTs), and device-based treatments n = 158 articles (n = 37 RCTs). Spikes in research activity surround FDA approval of therapeutics for each treatment modality. Research activity within the last decade has focused on topical and device-based treatments. Evidence for efficacy of device-based treatments is lacking from relatively few high-quality RCTs. Conclusion: With growing concern for non-dermatophyte mold onychomycosis and terbinafine resistance, researchers should validate the efficacy and safety of device-based treatments with high-quality studies.

Molecular Detection of Dermatophytes and Nondermatophytes in Onychomycosis in Antalya, Turkey.

Onychomycosis is a chronic nail infection, and dermatophytes, yeasts, and nondermatophytic molds may be the causative agents. This study aimed to determine the etiological agents of onychomycosis by using conventional and molecular methods. Between June 2020 and July 2021, 37 patients with a presumptive diagnosis of onychomycosis and mycological evidence (culture and/or EUROArray Dermatomycosis assay) were included in the study. Organisms detected in cultured nail specimens were identified by combined phenotypic characteristics and by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). An EUROarray Dermatomycosis assay was used for molecular detection of fungal pathogens. The EUROArray Dermatomycosis assay was positive for a single fungal target in 23 samples, and 14 samples were positive by culture. The most common pathogen was Trichophyton rubrum in both methods. Coinfection was detected in 14 samples by using molecular methods, and Trichophyton rubrum and Fusarium solani (9 samples) were the most common pathogens detected together. Trichophyton spp., nondermatophyte molds, and Candida spp. were detected in 33 (89.2%), 16 (43.2%), and 6 (16.2%) samples, respectively, when the two methods were evaluated together. Our results revealed that fungal culture allows the diagnosis of onychomycosis, but it is not as sensitive as the EUROArray Dermatomycosis test, especially in patients receiving antifungal therapy.

Clinico-mycological study of onychomycosis and in vitro antifungal susceptibility of Trichophyton rubrum.

Onychomycosis, a fungal nail infection, is primarily caused by dermatophytes, yeasts, and non-dermatophyte moulds (NDMs). The incidence of this disease and the predominance of specific pathogens vary across different regions and evolve. This study aimed to elucidate the epidemiology of onychomycosis and the pattern of causative pathogens in Beijing, and to ascertain the in vitro antifungal susceptibility profiles of Trichophyton rubrum against itraconazole (ITR), terbinafine (TER), and fluconazole (FLU). Involving 245 patients of onychomycosis with positive fungal culture results, the study implemented internal transcribed spacer (ITS) sequencing of ribosomal DNA (rDNA) on all collected samples. The mean age of the participants was 37.93 ± 13.73 years, with a male-to-female ratio of 1.53:1. The prevalence of toenail infections was significantly higher than that of fingernails. Distal and lateral subungual onychomycosis (DLSO) were the most frequent clinical classifications. PCR results indicated that dermatophytes were the most prevalent pathogens, followed by yeasts and NDMs, among which T. rubrum was the most dominant dermatophyte. TER demonstrated high sensitivity to T. rubrum. However, in clinical settings, some patients with onychomycosis exhibit a poor response to TER treatment. The relationship between in vitro antifungal sensitivity and clinical effectiveness is complex, and understanding the link between in vitro MIC values and clinical efficacy requires further investigation.

Pathogenicity and enzyme screening of some selected non-dermatophytic moulds.

Ten non-dermatophytic moulds isolated from both symptomatic and asymptomatic cattle skin, including Penicillum citrinum, Aspergillus welwitschiae, Aspergillus aculeatus, Curvularia kusanol, Cladosporium teniussmum, Pestalotiopsis microspora, Fusarium oxysporum, Fusarium linchenicola, Absidia sp. and Aspergillus fumigatus, were subjected to a pathogenicity test using albino mice. These isolates were also screened for five enzymes using a standard plate method. Results from pathogenicity tests showed that Absidia sp., Cladosporium tenuissimum and Aspergillus welwitschiae were able to elicit discoloration, lesion production and alopecia on the albino mice skin, respectively, providing evidence of clinical symptoms associated with cutaneous mycoses. The enzyme screening results revealed the highest zone of activity for keratinase (65 mm), amylase (86 mm), protease (60 mm), lipase (60 mm) and cellulase (86 mm) which were observed on Pestalotiopsis microspora, Aspergillus welwitschiae, Cladosporium tenuissimum, Aspergillus welwitschiae and Aspergillus welwitschiae respectively. Pathogenicity tests showed that some of these moulds may be virulent and this can be attributed to their possession of some virulence factors, including secretion of hydrolytic enzymes.

Onychomycosis: Prevalence, Fungal Pathogens, Risk Factors, and Antifungal Susceptibility Profile among People Living with Diabetes Mellitus in Kano, Northwestern Nigeria

Abstract Context: Onychomycosis is a fungal infection of the nail unit that over time results in dystrophy and disfigurement. It affects the quality of life and increases the prevalence and severity of foot ulcers in patients with diabetes. Aim: The study investigated the prevalence of onychomycosis, the associated fungal pathogens, and their antifungal susceptibility profile in a cohort of people living with diabetes (PLWDM) in Kano, Nigeria. Settings and Designs: This cross-sectional hospital-based study recruited and enrolled 300 PLWDM from two major diabetes treatment centers in Kano. Materials and Methods: Participants were screened for thickened, brittle, crumbly, or ragged nails, and 30 met the inclusion criteria. Sociodemographic data, clinical history, and other risk factors for onychomycosis were also evaluated. Toenail and fingernail, nail clippings, and scrapings were collected and cultured on Sabouraud dextrose agar (SDA). The identification of yeasts and mold isolates was performed using gram stain, germ tube test, CHROMagar, lactophenol cotton blue (LPCB) mount, and slide cultures. Antifungal susceptibility testing was achieved by the agar well-diffusion method. Statistical Analysis Used: The data generated were analyzed using descriptive statistics and associations between variables checked by the chi-square test or Fisher’s exact test. Results: The prevalence of onychomycosis was 63.3% (19/30), and fingernails were mostly affected. Fungal pathogens recovered include dermatophytes, yeasts, and non-dermatophyte molds, with a predominance of Aspergillus spps. (7/19 (36.8%)), Trichophytonmentagrophytes (4/19 (21.1%)), Trichophytonrubrum (4/19 (21.1%)), and Candidaalbicans (2/19 (10.5%)). A preponderance of the isolates shows a good susceptibility profile to itraconazole, ketoconazole, and clotrimazole, but demonstrated high resistance to fluconazole. Age and use of oral hypoglycemic agents were some of the risk factors identified. Conclusion: The study shows a high prevalence of onychomycosis among PLWDM in Kano and calls for routine screening to minimize or eliminate all possible complications.

Global prevalence of onychomycosis in general and special populations: An updated perspective.

Onychomycosis is a chronic nail disorder commonly seen by healthcare providers; toenail involvement in particular presents a treatment challenge. To provide an updated estimate on the prevalence of toenail onychomycosis. We conducted a literature search using PubMed, Embase and Web of Science. Studies reporting mycology-confirmed diagnoses were included and stratified into (a) populations-based studies, and studies that included (b) clinically un-suspected and (c) clinically suspected patients. A total of 108 studies were included. Based on studies that examined clinically un-suspected patients (i.e., with or without clinical features suggestive of onychomycosis), the pooled prevalence rate of toenail onychomycosis caused by dermatophytes was 4% (95% CI: 3-5) among the general population; special populations with a heightened risk include knee osteoarthritis patients (RR: 14.6 [95% CI: 13.0-16.5]), chronic venous disease patients (RR: 5.6 [95% CI: 3.7-8.1]), renal transplant patients (RR: 4.7 [95% CI: 3.3-6.5]), geriatric patients (RR: 4.7 [95% CI: 4.4-4.9]), HIV-positive patients (RR: 3.7 [95% CI: 2.9-4.7]), lupus erythematosus patients (RR: 3.1 [95% CI: 1.2-6.3]), diabetic patients (RR: 2.8 [95% CI: 2.4-3.3]) and hemodialysis patients (RR: 2.8 [95% CI: 1.9-4.0]). The prevalence of onychomycosis in clinically suspected patients was significantly higher likely due to sampling bias. A high degree of variability was found in a limited number of population-based studies indicating that certain pockets of the population may be more predisposed to onychomycosis. The diagnosis of non-dermatophyte mould onychomycosis requires repeat sampling to rule out contaminants or commensal organisms; a significant difference was found between studies that performed single sampling versus repeat sampling. The advent of PCR diagnosis results in improved detection rates for dermatophytes compared to culture. Onychomycosis is an underrecognized healthcare burden. Further population-based studies using standardized PCR methods are warranted.

Onychomycosis Caused by Aspergillus in a Patient with Leprosy: A Case Report

Aspergillus spp., one of the most common nondermatophyte molds (NDMs) that cause onychomycosis, are saprophytic fungi that can act as zoonotic agents and cause various health issues, including onychomycosis, in humans. Predisposing factors for onychomycosis include nail trauma, immunosuppression, and occupation. Nails in patients with leprosy are prone to change and develop onychomycosis due to unrecognized trauma to the nail area. Here, we report the case of a 25-year-old woman with 2-month history of white patches in fingernails and toenails, which were also brittle and damaged. She was a veterinarian who had frequent, direct interaction with animals, particularly dogs and cats. She denied trauma prior to the manifestation of symptoms and was undergoing leprosy treatment, including corticosteroids for leprosy reactions. Examination with potassium hydroxide revealed hyphae, and the nail culture revealed growth of fungal colonies with the characteristics of A. flavus. She received four cycles of itraconazole at 400 mg/day. Two of the three afflicted nails showed complete cure, whereas one nail showed mycologic cure. A. flavus is frequently found in animals, including dogs and cats and might have been a source of Aspergillus transmission, suggesting the patient's occupation and immunosuppression as risk factors for onychomycosis. Onychomycosis due to Aspergillus, particularly A. flavus, responds well to itraconazole pulse monotherapy.

Clinical and microbiological characteristics of onychomycosis in a tertiary hospital: a cross-sectional study

BACKGROUND Onychomycosis is a common fungal nail infection with a low cure rate. While dermatophytes are the most common causal agent for onychomycosis, the incidence of Candida and nondermatophyte mold (NDM) onychomycosis is increasing. This study aimed to analyze the clinical and microbiological characteristics of patients with onychomycosis. METHODS Patients who visited the Department of Dermatology and Venereology, Cipto Mangunkusumo Hospital, and were diagnosed with onychomycosis from 2017 to 2022 were included. Diagnosis was established through clinical examination, supported by the result of direct microscopic examination with potassium hydroxide. RESULTS Of 171 patients, 93.6% had onychodystrophy, 65.5% were females, and 62.0% were aged 19–59 years. Most patients had onychodystrophy in more than three nails, affecting fingernails (31.6%) and toenails (34.5%). Interestingly, 84.8% of patients had no history of nail diseases. The median onset of disease was 24.0 (1–1,040) weeks, while the median onychomycosis severity index was 10.0 (2–40). Most cases were caused by Candida albicans (48.3%). Fusarium was the only NDM documented (2.3%). Some patients were resistant to itraconazole (11.4%) and miconazole (4.5%). Overall, 49.1% of the patients were declared not cured. CONCLUSIONS Candida was the predominant cause of onychomycosis, and onychodystrophy was the dominant feature. Current treatment regimens with systemic or topical antifungal agents did not yield satisfactory results, with more than half of the patients deemed not cured.

Clinical Diagnosis and Laboratory Testing of Abnormal Appearing Toenails: A Retrospective Assessment of Confirmatory Testing for Onychomycosis in the United States, 2022-2023.

Onychomycosis is an under-recognized healthcare burden. Despite the risk of misdiagnosis, confirmatory laboratory testing is under-utilized. Histopathologic examination with polymerase chain reaction (PCR) is currently the most effective diagnostic method; it offers direct detection and identification of a fungal invasion. In this retrospective cohort study, we assessed confirmatory testing results, with matching clinical diagnoses, in 96,293 nail specimens submitted during a 9-month period from 2022 to 2023. Toenail specimens were examined using fungal culture, histopathology and/or PCR. Clinical diagnoses were identified using the International Classification of Diseases 10th Revision codes. For clinically diagnosed onychomycosis patients, the overall positivity rate was 59.4%; a similar positivity rate (59.5%) was found in patients with clinically diagnosed non-fungal nail dystrophy. Performing a histopathologic examination with PCR was more likely to provide pathogen identification results than using fungal culture. Male patients had a higher rate of onychomycosis overall; however, female patients had more non-dermatophyte mold onychomycosis caused by Aspergillus. Clinically diagnosed onychomycosis patients with a co-diagnosis of tinea pedis were more likely to test positive for onychomycosis by PCR (odds ratio [OR]: 4.2; 95% confidence interval [CI]: 2.7-6.4), histopathology (OR: 2.5; 95% CI: 2.0-3.1) and fungal culture (OR: 3.2; 95% CI: 1.5-6.6). Our results support the use of confirmatory laboratory testing when there is a clinical diagnosis of onychomycosis.

Onychomycosis caused by &lt;i&gt;Acremonium species:&lt;/i&gt; A case report

Onychomycosis is a common condition constituting fungal infection of nails. It is generally caused by dermatophytes but non-dermatophytic mold and yeast as its causative agent are on the rise. Acremonium, a non-dermatophytic mold, is commonly found in decaying vegetation, soil, and air. Identification of the causative agent is important as non-dermatophytic molds are resistant to commonly used antifungals. This is a case of an Indian woman who presented with onychomycosis of the toenail and the causative agent was documented and reported as Acremonium species.

Multi-Convolutional Neural Network-Based Diagnostic Software for the Presumptive Determination of Non-Dermatophyte Molds

Based on the literature data, the incidence of superficial and invasive non-dermatophyte mold infection (NDMI) has increased. Many of these infections are undiagnosed or misdiagnosed, thus causing inadequate treatment procedures followed by critical conditions or even mortality of the patients. Accurate diagnosis of these infections requires complex mycological analyses and operator skills, but simple, fast, and more efficient mycological tests are still required to overcome the limitations of conventional fungal diagnostic procedures. In this study, software has been developed to provide an efficient mycological diagnosis using a trained convolutional neural network (CNN) model as a core classifier. Using EfficientNet-B2 architecture and permanent slides of NDM isolated from patient’s materials (personal archive of Prof. Otašević, Department of Microbiology and Immunology, Medical Faculty, University of Niš, Serbia), a multi-CNN model has been trained and then integrated into the diagnostic tool, with a 93.73% accuracy of the main model. The Grad-CAM visualization model has been used for further validation of the pattern recognition of the model. The software, which makes the final diagnosis based on the rule of the major method, has been tested with images provided by different European laboratories, showing an almost faultless accuracy with different test images.

Preparation and characterization of a curcumin nanoemulsion gel for the effective treatment of mycoses

Fungal infections of skin including mycoses are one of the most common infections in skin or skins. Mycosis is caused by dermatophytes, non-dermatophyte moulds and yeasts. Various studies show different drugs to treat mycoses, yet there is need to treat it with applied drugs delivery. This study was designed to prepare a bio curcumin (CMN) nanoemulsion (CMN-NEs) for transdermal administration to treat mycoses. The self-nanoemulsification approach was used to prepare a nanoemulsion (NE), utilizing an oil phase consisting of Cremophor EL 100 (Cre EL), glyceryl monooleate (GMO), and polyethylene glycol 5000 (PEG 5000). Particle size (PS), polydispersity index (PDI), zeta potential (ZP), Fourier transform infrared (FTIR) spectrophotometric analysis, and morphological analyses were performed to evaluate the nanoemulsion (NE). The in vitro permeation of CMN was investigated using a modified vertical diffusion cell with an activated dialysis membrane bag. Among all the formulations, a stable, spontaneously produced nanoemulsion was determined with 250 mg of CMN loaded with 10 g of the oil phase. The average droplet size, ZP, and PDI of CMN-NEs were 90.0 ± 2.1 nm, − 7.4 ± 0.4, and 0.171 ± 0.03 mV, respectively. The release kinetics of CMN differed from zero order with a Higuchi release profile as a result of nanoemulsification, which also significantly increased the flux of CMN permeating from the hydrophilic matrix gel. Overall, the prepared nanoemulsion system not only increased the permeability of CMN but also protected it against chemical deterioration. Both CMN-ME (24.0 ± 0.31 mm) and CMN-NE gel (29.6 ± 0.25 mm) had zones of inhibition against Candida albicans that were significantly larger than those of marketed Itrostred gel (21.5 ± 0.34 mm). The prepared CMN-NE improved the bioavailability, better skin penetration, and the CMN-NE gel enhanced the release of CMN from the gel matrix on mycotic patients.

Detection of 2-ethyl-1-hexanol and its modulating effect in biofilm of Fusarium oxysporum.

In immunocompetent individuals, Fusarium spp. stands out as the causative agent of onychomycosis, among the non-dermatophyte molds. Despite evidence indicating that Fusarium oxysporum organizes itself in the form of a biofilm causing onychomycosis, there is little literature on the etiopathogenesis of the biofilm on the nail, specifically the signaling molecules present, known as quorum sensing (QS). Thus, this study detected the presence of a molecule related to QS from the exvivo biofilm of F. oxysporum on human nail and investigated its effect on preformed biofilm invitro. The detection and physicochemical characterization of a QS molecule, from the extracellular matrix (ECM), was carried out by Fourier transform infrared (FTIR) spectroscopy with an attenuated total reflectance (ATR) accessory and by headspace gas chromatography coupled to mass spectrometry (GC-MS) analyses. Determination of viable cells, cell activity, total biomass, ECM components and scanning electron microscopy (SEM) were performed to evaluate the influence of the QS molecule on the invitro biofilm of F. oxysporum. The beginning, in the exvivo biofilm of F. oxysporum on human nails, the volatile organic compound 2-ethyl-1-hexanol (2EH) was detected as a component of QS. Thereafter invitro analyses, synthetic 2EH was able to modulate the biofilm by stimulating its filament, increasing total biomass and ECM production in terms of total carbohydrates, but with a reduction in total proteins and nucleic acids. We thus evidence, for the first time, the presence of 2EH in the biofilm of F. oxysporum, developed on the human nail, and the invitro action of this compound as a QS molecule.

A comprehensive review of nondermatophyte mould onychomycosis: Epidemiology, diagnosis and management.

Nondermatophyte moulds (NDMs) are widely distributed and can be detected in association with mycotic nails; however, sometimes it can be challenging to establish the role of NDMs in the pathogenesis of onychomycosis (i.e. causative vs. contaminant). In studies where the ongoing invasive presence of NDMs is confirmed through repeat cultures, the global prevalence of NDMs in onychomycosis patients is estimated at 6.9% with the 3 most common genus being: Aspergillus, Scopulariopsis and Fusarium. NDM onychomycosis can, in many cases, appear clinically indistinguishable from dermatophyte onychomycosis. Clinical features suggestive of NDMs include proximal subungual onychomycosis with paronychia associated with Aspergillus spp., Fusarium spp. and Scopulariopsis brevicaulis, as well as superficial white onychomycosis in a deep and diffused pattern associated with Aspergillus and Fusarium. Longitudinal streaks seen in patients with distal and lateral onychomycosis may serve as an additional indicator. For diagnosis, light microscopic examination should demonstrate fungal filaments consistent with an NDM with at least two independent isolations in the absence of a dermatophyte; the advent of molecular testing combined with histological assessment may serve as an alternative with improved sensitivity and turnover time. In most instances, antifungal susceptibility testing has limited value. Information on effective treatments for NDM onychomycosis is relatively scarce, unlike the situation in the study of dermatophyte onychomycosis. Terbinafine and itraconazole therapy (continuous and pulsed) appear effective to varying extents for treating onychomycosis caused by Aspergillus, Fusarium or Scopulariopsis. There is scant literature on oral treatments for Neoscytalidium.

The Plant Defensin Ppdef1 Is a Novel Topical Treatment for Onychomycosis.

Onychomycosis, or fungal nail infection, causes not only pain and discomfort but can also have psychological and social consequences for the patient. Treatment of onychomycosis is complicated by the location of the infection under the nail plate, meaning that antifungal molecules must either penetrate the nail or be applied systemically. Currently, available treatments are limited by their poor nail penetration for topical products or their potential toxicity for systemic products. Plant defensins with potent antifungal activity have the potential to be safe and effective treatments for fungal infections in humans. The cystine-stabilized structure of plant defensins makes them stable to the extremes of pH and temperature as well as digestion by proteases. Here, we describe a novel plant defensin, Ppdef1, as a peptide for the treatment of fungal nail infections. Ppdef1 has potent, fungicidal activity against a range of human fungal pathogens, including Candida spp., Cryptococcus spp., dermatophytes, and non-dermatophytic moulds. In particular, Ppdef1 has excellent activity against dermatophytes that infect skin and nails, including the major etiological agent of onychomycosis Trichophyton rubrum. Ppdef1 also penetrates human nails rapidly and efficiently, making it an excellent candidate for a novel topical treatment of onychomycosis.

Onychomycosis caused by dematiaceous fungi: A four-year study on agricultural workers of Assam, India.

Onychomycosis caused by dematiaceous fungi is rarely reported and the identification is also quite tricky due to poor sporulation. Recent emergence of dematiaceous fungi as a major cause of onychomycosis is a matter of concern in the field of mycology. Therefore, this study aimed to understand the dematiaceous fungi as a possible cause of onychomycosis, especially among agricultural workers. In addition, the evaluation of the antifungal susceptibility patterns led to the idea of an accurate drug that will help to treat and prevent antifungal resistance. The standard procedure was followed for direct microscopic examination and fungi isolation. Furthermore, antifungal susceptibility testing was conducted in accordance with the Clinical and Laboratory Standards Institute M-38-A2 protocol. Both potassium hydroxide and fungal positivity were found in 275 out of 356 suspected cases, 52%, 4.3%, 28.7%, and 14.9% of which were non-dermatophytic molds (NDMs), yeast, dermatophytes, and sterile hyphae, respectively. Among NDMs (52%, n=143), 45.5% (n=65) were hyaline hyphomycetes and 54.5% (n=78) were dematiaceous hyphomycetes. Among dematiaceous fungi, Pestalotiopsis spp. and Arthrinium spp. were the commonly isolated ones. Additionally, azoles, amphotericin-B, and anidulafungin showed excellent antifungal activity against tested isolates. Dematiaceous fungi are now becoming a potential cause of onychomycosis. A more detailed study is needed on the identification of these emerging isolates and the mode of action of antifungal drugs for a better treatment strategy.