Onychomycosis: modern diagnostic and treatment approaches

Candida albicans skin infection in diabetic patients: An updated review of pathogenesis and management

Candida species, commensal residents of human skin, are recognized as the cause of cutaneous candidiasis across various body surfaces. Individuals with weakened immune systems, particularly those with immunosuppressive conditions, are significantly more susceptible to this infection. Diabetes mellitus, a major metabolic disorder, has emerged as a critical factor inducing immunosuppression, thereby facilitating Candida colonization and subsequent skin infections. This comprehensive review examines the prevalence of different types of Candida albicans-induced cutaneous candidiasis in diabetic patients. It explores the underlying mechanisms of pathogenicity and offers insights into recommended preventive measures and treatment strategies. Diabetes notably increases vulnerability to oral and oesophageal candidiasis. Additionally, it can precipitate vulvovaginal candidiasis in females, Candida balanitis in males, and diaper candidiasis in young children with diabetes. Diabetic individuals may also experience candidal infections on their nails, hands and feet. Notably, diabetes appears to be a risk factor for intertrigo syndrome in obese individuals and periodontal disorders in denture wearers. In conclusion, the intricate relationship between diabetes and cutaneous candidiasis necessitates a comprehensive understanding to strategize effective management planning. Further investigation and interdisciplinary collaborative efforts are crucial to address this multifaceted challenge and uncover novel approaches for the treatment, management and prevention of both health conditions, including the development of safer and more effective antifungal agents.

[Conventional and molecular diagnostics in onychomycosis-part 2 : Molecular identification of causative dermatophytes by polymerase chain reaction and sequence analysis of the internal transcribed spacer region of ribosomal DNA]

Dermatophyte identification using traditional methods such as optics-based direct fluorescence microscopy and culture is nowadays supplemented by molecular biological methods. The validity of dermatophyte DNA detection with direct uniplex-polymerase chain reaction-enzyme immunoassay (PCR-EIA) in nail samples was proven by sequence analysis of the ribosomal internal transcribed spacer (ITS) region. A total of 108 dermatophytes, isolated from patients with onychomycosis, were positive for Trichophyton rubrum (TR) and Trichophyton interdigitale (TI) in culture and/or uniplex-PCR-EIA. Conventional methods for dermatophyte identification were complemented by direct uniplex-PCR-EIA and sequence analysis of the ribosomal ITS region (18S rRNA, ITS1, 5.8S rRNA, ITS2, 28S rRNA). Of 108 patients (average age 62, median age 73), 56 showed cultural growth with 31 of them being identified as TR and 23 as TI. There was high agreement with the sequence analysis. Surprisingly, the pathogen of a single nail sample was identified as T. quinckeanum (formerly T. mentagrophytes sensu stricto), a rare zoophilic dermatophyte in Germany. A single TI strain turned out to be a misidentified T. tonsurans based on the sequence analysis. In all, 34 of the 52 specimens lacking cultural growth were detected by PCR as TR, and 18 specimens could be identified as TI. The results of dermatophyte identification of culture-negative nail samples were also in agreement with the results of sequence analysis. Molecular biological methods are well applicable, and they show high reliability for direct dermatophyte identification in nail samples without prior cultivation. Especially for nail samples without cultural growth, PCR-based dermatophyte identification was highly specific and sensitive.

Novel Discoveries and Clinical Advancements for Treating Onychomycosis: A Mechanistic Insight

Onychomycosis continues to be the most challenging disease condition for pharmaceutical scientists to develop an effective drug delivery system. Treatment challenges lie in incomplete cure and high relapse rate. Present compilation provides cumulative information on pathophysiology, diagnostic techniques, and conventional treatment strategies to manage onychomycosis. Novel technologies developed for successful delivery of antifungal molecules are also discussed in brief. Multidirectional information offered by this article also unlocks the panoramic view of leading patented technologies and clinical trials. The obtained clinical landscape recommends the use of advanced technology driven approaches, as a promising way-out for treatment of onychomycosis. Collectively, present review warrants the application of novel technologies for the successful management of onychomycosis. This review will assist readers to envision a better understanding about the technologies available for combating onychomycosis. We also trust that these contributions address and certainly will encourage the design and development of nanocarriers-based delivery vehicles for effective management of onychomycosis.

Efficacy of Bovine Nail Membranes as In Vitro Model for Onychomycosis Infected by Trichophyton Species

Onychomycosis is a fungal infection caused by different etiologic agents, including dermatophytes that specifically colonize keratin-rich substrates. The aim of this work was to investigate mechanical modifications of bovine membranes (used as an in vitro nail model) placed in contact with Trichophyton species. Trichophyton strains were isolated from toenails specimens. The procedure was set up by spreading T. rubrum,T. interdigitale, and T. mentagrophytes strains on Petri dishes with minimal and rich media; after that, bovine membranes were placed in the center. After 27 days, T. interdigitale and T. mentagrophytes significantly reduced the thickness of the colonized membranes, whereas two T. rubrum strains showed the highest degradation limited to the small colonized area. These results were confirmed by SEM images of the colonization profile on membranes. Mechanical analyses performed on membranes were used as an innovative method to evaluate the thickness and structural integrity of membranes variation following fungal colonization. In conclusion, mechanical analyses of substrate may be used as a procedure for the development of a new onychomycosis diagnosis test in order to develop personalized and strain-specific treatment.

Meta-analysis of the antifungal activities of three essential oils as alternative therapies in dermatophytosis infections

Aims

This work examines the available scientific evidence about the efficiency of essential oils (EO) as an alternative therapy to traditional treatment of fungal infections, including onychomycosis, assessing the effect of the three EO most frequently studied for their antifungal activity (thyme, cinnamon and tea tree EO) against three causative agents of fungal diseases in humans: Trichophyton rubrum, Trichophyton mentagrophytes complex and Candida albicans.

Methods and Results

The PRISMA statement protocol was followed to conduct a bibliographical search and 54 articles that met all the inclusion criteria were retrieved. Differences were observed in the MIC and MFC values depending on the micro‐organism strain and the EO used. The lowest MIC were observed with Cinnamomum zeylanicum EO (0.013–1120 μl ml⁻¹) against the three micro‐organisms. For MFC, the lowest value was found for Thymus vulgaris EO (4.2 μl ml⁻¹) against Trichophyton rubrum.

Conclusions

The antifungal effects of EO could be a very promising solution to overcome the therapeutic shortcomings of antimycotic medication. More experiments are needed to examine the properties of these oils to devise effective and nonaggressive therapies for treatment of dermatophytosis.

Significance and Impact of Study

The results indicate that EO remain good candidates for future treatments and could provide a solution for failed medications and/or adverse reactions to current pharmacological treatments.

Correlation of clinical characteristics, by calculation of SCIO index, with the laboratory diagnosis of onychomycosis

INTRODUCTION

Onychomycosis is a chronic fungal infection with increasing incidence and the global prevalence is estimated to be 5.5%. The aim of our study was to perceive objectively severity of onychomycosis by calculating Scoring Clinical Index for Onychomycosis and to correlate this index with accurate laboratory diagnosis in our patients.

MATERIALS AND METHODS

The study population comprised of 417 patients with laboratory confirmed onychomycosis. For each patient, we recorded basic demographic information, site of infection, the most affected nail with onychomycosis, clinical presentation, and type of onychomycosis. The evaluation of the disease severity was based on Scoring Clinical Index for Onychomycosis which was calculated for every patient separately. Mycological identification was done by microscopy and fungal culture.

RESULTS

The majority of patients had distal and lateral subungual onychomycosis (95.44%) that was localized on big toe (62.59%), with female to male ratio 1.24:1. Male patients had significantly more nails affected with onychomycosis compared with female patients (p = 0.011), while female had significantly more often onychomycosis on fingernails 2-5 (p < 0.05), and they reported significantly more often pain (p < 0.05) and esthetic problems (p < 0.05). Mean Scoring Clinical Index for Onychomycosis was 16.76. Dermatophytes were most frequently isolated (91.85%). In patients with onychomycosis caused by dermatophytes, Scoring Clinical Index for Onychomycosis had significantly higher values (p = 0.032).

CONCLUSION

Comprehensive understanding of disease characteristics will allow introduction of individualized treatment plan for each patient, based on proper fungal identification and standardized method of evaluating disease severity, which could help the patient achieve a complete cure.

Preliminary Evidence of the Efficacy of Nitric Acid Treatment in Onychomycosis

Onychomycosis is the main cause of toenail disorders and is produced by a fungal infection. It is becoming more prevalent because of new lifestyles and immunosuppression statuses. The therapeutic approach to onychomycosis is under considerable study because of the lengthy treatments that require strong patient commitment, the limited efficacy of treatments, the inclusion of active substances that can be hepatotoxic and cause pharmacological interactions, and/or the questionable efficacy of treatments due to a lack of clinical trials. This study responds to the demand for rapid treatment with minimal pharmacological interactions. Methods: The efficacy of nitric acid 60% treatment in patients with onychomycosis was monitored and studied. The antifungal efficacy of nitric acid was measured by microbiological culture before and after treatment and the clinical evolution of nail dystrophy was quantitatively measured by monitoring with the Onychomycosis Severity Index (OSI). Results: The results show that, with the protocol used, nitric acid 60% painlessly cured 40% (microbiologic cure) of the cases treated, and in all cases, clinical improvement was observed (p = 0.011). Conclusions: The treatment with nitric acid 60% is as efficient as conventional treatments, requires less patient compliance of the treatment and produces no pharmacological interactions, providing alternative treatment in the case of hepatotoxicity.

Molecular characterization and antifungal activity against non-dermatophyte molds causing onychomycosis

Onychomycosis is a fungal disease that caused by different types of fungi. Non-dermatophyte molds are a large saprophytic fungi group that live in nature and could affect traumatic nails. The aim of this study was to identify non-dermatophyte molds causing onychomycosis and evaluation of several antifungal activities against the isolates. The samples consisted of 50 non-dermatophyte molds isolated from patients with onychomycosis confirmed by direct and culture examination fungal. DNA was extracted, amplified, and sequenced. Disk diffusion method was used to evaluate itraconazole, fluconazole, ketoconazole, terbinafine, posaconazole, and econazole activity against the isolates. The species identified as: Aspergillus flavus 22 (44%), A. niger 12 (24%), A. fumigates, 3 (6%), A. sydowii 3 (6%), A. terreus 1 (2%), Penicillium commune 2 (4%), P. glabrum 2 (4%), P. chrysogenum, 1 (2%), Fusarium solani 3 (6%) and F. thapsinum 1 (2%). Most of the samples were sensitive to terbinafine, itraconazole, and econazole and 94% of the isolates were resistant to fluconazole. This study showed that Aspergillus species were the most common cause of non-dermatophyte mold onychomycosis and fluconazole was the most resistant antifungals. Care must be taken to choose the appropriate antifungal drug for a better cure.

Identification of Fungi Involved in Onychomycosis in Patients of a Spanish Rural Area

Onychomycosis is one of the most frequent reasons for visiting podiatrist clinics. Complementary tests and the accurate identification of the infectious agents are key issues for a successful treatment of onychomycosis. This is particularly important when lifestyle, age and immunodepressed patients increase the prevalence of non-dermatophyte fungal infection. In this paper, we describe issues related to onychomycosis prevalence in a population of patients, mostly with rural lifestyles, visiting a podiatry clinic in a rural area of Spain. A total of 51 cases were studied with an average age of 65.96 ± 21.28 years (the youngest being 16 years and the oldest being 95 years). Fungal agents were isolated using conventional sampling and microbiological culture techniques. The results obtained with these techniques were compared with the results obtained with a direct methodology using molecular biology, by PCR and nucleotide sequencing of the ITS-5.8S rDNA fragment. The classical culture methodology confirmed the infection in 76.5% of the samples (n = 39), while the PCR confirmed the infection in 84.3% (n = 51) of the nails, although the difference between these results did not show statistical significance (p = 0.388). We found a high variability in agents, with more yeasts than dermatophytes as etiological agents of onychomycosis. However, only among individuals older than 65 years, was the difference between yeasts (82%) and dermatophytes (18%) was statistically significant (p = 0.004). Among the agents of non-dermatophyte onychomycosis, we found predominantly fungi (yeasts) of the Candida genus, interestingly with no isolates of Candida albicans, and moulds of the Aspergillus genus.

Ellagic Acid Inhibits Trichophyton rubrum Growth via Affecting Ergosterol Biosynthesis and Apoptotic Induction

Background

Trichophyton rubrum, among other dermatophytes, is a major causative agent for superficial dermatomycoses like onychomycosis and tinea pedis, especially among pediatric and geriatric populations. Ellagic acid (EA) and shikonin (SK) have been reported to have many bioactivities, including antifungal activity. However, the mechanism of EA and SK on Trichophyton rubrum has not yet been reported.

Objectives

The purposes of this study were to evaluate the antifungal activities of EA and SK against Trichophyton rubrum and to illuminate the underlying action mechanisms.

Methods

The effect of EA (64, 128, and 256 μg/mL) and SK (8, 4, and 2 μg/mL) on Trichophyton rubrum was investigated with different doses via detecting cell viability, ultrastructure with using a scanning electron microscope (SEM), cell apoptosis and necrosis by using the flow cytometry instrument technique (FCIT), and the ergosterol biosynthesis pathway-related fungal cell membrane key gene expressions in vitro.

Results

SEM detection revealed that the T. rubrum cell surface was shrivelled, folded, and showed deformation and expansion, visible surface peeling, and broken hyphae, and cell contents overflowed after being treated with EA and SK; the cell apoptosis rate was significantly increased in dose-dependent manner after T. rubrum was treated with EA and SK; the qPCR results showed that mRNA expression of MEP4 and SUB1 was downregulated in EA- and SK-treated groups.

Conclusions

Overall, our results revealed the underlying antifungal mechanism of EA and SK, which may be related to the destruction of the fungal cell membrane and inhibition of C14 demethylase and the catalytic rate of squalene cyclooxidase in the ergosterol biosynthesis pathway via downregulation of MEP4 and SUB1, suggesting that EA and SK have the potential to be developed further as a natural antifungal agent for clinical use.

Onychomycosis in Northwestern Greece Over a 7-Year Period

Onychomycosis is considered as one of the major public health problems with a global distribution associated with geographic, demographic and environmental factors, underlying comorbidities and immunodeficiency disorders. This study was conducted to investigate the etiological agents of onychomycosis, in Northwestern Greece during a 7-year period. The study population included 1095 outpatients with clinically suspected onychomycosis that presented to the University Hospital of Ioannina, NW Greece (2011–2017). Samples were examined for causative fungi, and mycological identification was established using standard mycological methods. Demographic data of each patient, comorbidities, localization of infection and history of previous fungal infection were collected. Onychomycosis was diagnosed in 317 of the 1095 suspected cases (28.9%) and the most frequently isolated pathogens were yeasts (50.8%) followed by dermatophytes (36.9%) and non-dermatophyte molds (NDMs) (12.3%). Dermatophytes were mostly involved in toenail onychomycosis (90.6%) and more commonly affected males than females (57.3% vs. 42.7%), while the predominantly isolated pathogen was Τrichophyton rubrum (74.4%) followed by Τrichophyton interdigitale (21.4%). Candida albicans was the most prevalent isolated yeast (82%), whereas among the cases with onychomycosis due to NDMs, Aspergillus spp. were isolated as the principal species (59%). Continuous monitoring should be performed in order to identify possible trends and shifts in species isolation rates and to evaluate the impact of onychomycosis among the general population and high-risk groups.

Biological properties of Phoma macrostoma related to non-dermatophyte onychomycosis

We report a rare case of non-dermatophytic onychomycosis of the toenail caused by Phoma macrostoma. Was studied the biological properties of the strain isolated in Kazakhstan. P. macrostoma forms pink colonies, the reverzum is pink-orange. The mycelium is colorless, septate. The appearance of growth tubes from pycnidospores occurs within 12 hours, mycelial growth and branching after 18 hours, the appearance of pycnids is 48 hours. The saccharolytic and urease activity of the strain is low.

Candida sp. Infections in Patients with Diabetes Mellitus

Candidiasis has increased substantially worldwide over recent decades and is a significant cause of morbidity and mortality, especially among critically ill patients. Diabetes mellitus (DM) is a metabolic disorder that predisposes individuals to fungal infections, including those related to Candida sp., due to a immunosuppressive effect on the patient. This review aims to discuss the latest studies regarding the occurrence of candidiasis on DM patients and the pathophysiology and etiology associated with these co-morbidities. A comprehensive review of the literature was undertaken. PubMed, Scopus, Elsevier’s ScienceDirect, and Springer’s SpringerLink databases were searched using well-defined search terms. Predefined inclusion and exclusion criteria were applied to classify relevant manuscripts. Results of the review show that DM patients have an increased susceptibility to Candida sp. infections which aggravates in the cases of uncontrolled hyperglycemia. The conclusion is that, for these patients, the hospitalization periods have increased and are commonly associated with the prolonged use of indwelling medical devices, which also increase the costs associated with disease management.

Novel Drug Delivery Strategies for the Treatment of Onychomycosis

Onychomycosis accounts for 50% of all nail disease cases and is commonly caused by dermatophytes. It was primarily considered a cosmetic problem but has been garnering attention lately due to its persistent nature and difficult treatment with relapses. With prolonged treatment duration and high cost involved in treating onychomycosis, several attempts have been made in overcoming the rigid nail barrier. The conventional treatment of onychomycosis involves oral and topical therapy. The oral antifungal agents though quite effective, are hepato-toxic and cause drug-drug interactions. Topical therapy is more patient compliant being devoid of such adverse effects but it suffers from another setback of improper nail penetration. Amorolfine and ciclopirox nail lacquers are popular market products. Since decades, efforts have been made to enhance topical delivery for efficiently treating onychomycosis. Mechanical, physical and chemical methods have been employed. Despite all the attempts made, the nail delivery issues are far from being solved. Recently, the focus has shifted to novel drug delivery systems like nanoparticles, microemulsions, polymeric films and nail lacquers for enhanced drug permeation and localized therapy. The research around the world is exploring their potential as effective treatment options. This review intends to further explore the novel delivery strategies to treat a persistent fungal infection like onychomycosis.

Epidemiological survey of onychomycosis pathogens in Japan by real-time PCR

In Japan, an epidemiological survey of onychomycosis pathogens was performed using culture methods; however, the positive culture rate was 40% or less. As part of an epidemiological survey of dermatomycoses in Japan, we overcame this low positive rate by employing a real-time polymerase chain reaction (PCR) assay that allowed rapid and accurate detection and identification. In 2011, nail specimens were collected from patients at nine institutes in various prefectures in Japan and diagnosed as onychomycosis. For the detection and identification of the main pathogens causing onychomycosis, we performed real-time PCR using specific TaqMan® MGB probes and primer sets. Of the 496 onychomycosis samples, real-time PCR detected 382 cases (77.0%) caused by Trichophyton rubrum; 74 cases (15.0%) caused by Trichophyton interdigitale; and eight cases (1.6%) caused by Candida albicans. The real-time PCR positive rate was 96.2%. The most frequent pathogen was T. rubrum throughout life, with the number of patients affected peaking in the range of 60 to 69 years of age and no significant differences in the composition of causative pathogens by sex. We were able to detect and identify pathogens from almost all specimens and succeeded in analyzing the pathogens involved in onychomycosis cases in Japan. These data confirmed that our real-time PCR method was effective for detecting and identifying the main fungal pathogens from onychomycosis specimens.

Infrared spectroscopy as a novel tool to diagnose onychomycosis

BACKGROUND

The determination of causative organisms of onychomycosis is still not optimal. There remains a need for a cheap, fast and easy-to-perform diagnostic tool with a high capacity to distinguish between organisms.

OBJECTIVES

To determine whether attenuated total-reflectance Fourier transform infrared (ATR-FTIR) spectroscopy can detect and differentiate causative agents in culture-based, ex vivo nail and in vivo nail models.

METHODS

A methodological study was conducted. Both the ex vivo nail model and in vivo pilot study were carried out in an academic university hospital.

RESULTS

Analysis of cultured fungi revealed spectral differences for dermatophytes (1692-1606 and 1044-1004 cm^-1 ) and nondermatophytes and yeasts (973-937 cm^-1 ), confirmed by dendrograms showing an excellent separation between samples from different genera or species. Exploration of dermatophytes, nondermatophytes and yeasts growing on ex vivo nails exposed prominent differences from 1200 to 900 cm^-1 . Prediction models resulted in a 96·9% accurate classification of uninfected nails and nails infected with dermatophytes, nondermatophytes and yeasts. Overall correct classification rates of 91·0%, 97·7% and 98·6% were obtained for discrimination between dermatophyte, nondermatophyte and yeast genera or species, respectively. Spectra of in vivo infected and uninfected nails also revealed distinct spectral differences (3000-2811 cm^-1 , 1043-950 cm^-1 and 1676-1553 cm^-1 ), illustrated by two main clusters (uninfected vs. infected) on a dendrogram.

CONCLUSIONS

Our data suggest that ATR-FTIR spectroscopy may be a promising, fast and accurate method to determine onychomycosis, including identification of the causative organism, bypassing the need for lengthy fungal cultures.

Epidemiology of onychomycosis in Serbia: a laboratory-based survey and risk factor identification

Onychomycosis is a fungal infection of the fingernails and/or toenails caused by dermatophytes, yeasts and non-dermatophyte moulds. The epidemiology of onychomycosis in Serbia is yet to be fully established. This epidemiological study was aimed at evaluating the epidemiology of onychomycosis in a sample of the Serbian patients at risk of onychomycosis, to determine the fungal aetiological agents and to identify the possible risk factors. The study population included 374 patients from six centres in Serbia with suspected onychomycosis. Demographic data, data about comorbidities, lifestyle, clinical aspects of onychomycosis, trauma, excessive perspiration and personal and family history of previous onychomycosis were studied. Laboratory confirmation of diagnosis was done by direct microscopy, fungal culture and PCR. Diagnosis of onychomycosis was confirmed in 50.8% of patients, who tested positive to at least one laboratory test (direct microscopy, fungal culture or PCR). Trichophyton rubrum was predominant both on toenails (85.98%) and on fingernails (38.46%). Independent risk factors for onychomycosis were: old age (OR = 2.285; P < 0.001), family history of previous onychomycosis and/or tinea pedis (OR = 2.452; P = 0.005), excessive perspiration (OR = 2.165; P = 0.002) and higher degree of hyperkeratosis (OR = 1.755; P = 0.020). This is a first epidemiological study of onychomycosis from Serbia.

PCR and real-time PCR approaches to the identification of Arthroderma otae species Microsporum canis and Microsporum audouinii/Microsporum ferrugineum

OBJECTIVES

The identification of species in the Arthroderma otae complex is essential to determine the origin of infection and to eliminate the risk of transmission. Microsporum canis is a zoophilic species, whereas Microsporum audouinii and Microsporum ferrugineum are anthropophilic species. In this paper, we propose alternative methods that permit species-specific identification of both anthropophilic and zoophilic members of the A. otae complex METHODS: Two PCR assays were designed based on differences in the DNA fragment encoding β-tubulin and were applied in both traditional and real-time PCR using DNA isolated by rapid method from culture.

RESULT

The two assays presented in this study enable the identification of M. canis and M. audouinii/M. ferrugineum with 100% sensitivity and specificity by both traditional and real-time PCR.

CONCLUSION

We developed a new diagnostic assay using specific primers and both traditional and real-time PCR reactions that can be applied in routine laboratory praxis as well as in epidemiological studies to detect M. canis and M. audouinii/M. ferrugineum DNA from a pure culture.

Diagnosis and Management of Onychomycosis Perspectives from a Joint Podiatric Medicine-Dermatology Roundtable

Onychomycosis is a fungal infection, and, as such, one of the goals of treatment should be eradication of the infective agent. Despite this, in contrast to dermatologists, many podiatric physicians do not include antifungals in their onychomycosis treatment plans. Before initiating treatment, confirmation of mycologic status via laboratory testing (eg, microscopy with potassium hydroxide preparation, histopathology with periodic acid-Schiff staining, fungal culture, and polymerase chain reaction) is important; however, more podiatric physicians rely solely on clinical signs than do dermatologists. These dissimilarities may be due, in part, to differences between specialties in training, reimbursement patterns, or practice orientation, and to explore these differences further, a joint podiatric medicine-dermatology roundtable was convened. In addition, treatment options have been limited owing to safety concerns with available oral antifungals and relatively low efficacy with previously available topical treatments. Recently approved topical treatments-efinaconzole and tavaborole-offer additional options for patients with mild-to-moderate disease. Debridement alone has no effect on mycologic status, and it is recommended that it be used in combination with an oral or topical antifungal. There is little to no clinical evidence to support the use of lasers or over-the-counter treatments for onychomycosis. After a patient has achieved cure (absence of clinical signs or absence of fungus with minimal clinical signs), lifestyle and hygiene measures, prophylactic/maintenance treatment, and proactive treatment for tinea pedis, including in family members, may help maintain this status.

Synergistic combination of violacein and azoles that leads to enhanced killing of major human pathogenic dermatophytic fungi Trichophyton rubrum

Superficial mycoses caused by dermatophytic fungi such as Trichophyton rubrum represent the most common type of worldwide human infection affecting various keratinized tissues in our body such as the skin, hair, and nails, etc. The dermatophytic infection is a significant public health threat due to its persistent nature and high recurrence rates, and thus alternative treatments to cure this fungal infection are urgently required. The present study mainly focused on the synergistic activity of violacein with four azole drugs (ketoconazole, fluconazole, clotrimazole, and itraconazole) against T. rubrum. The synergistic antifungal activities of violacein and azoles were measured by checkerboard microdilution and time-kill assays. In our study, combinations of violacein and azoles predominantly recorded synergistic effect (FIC index < 0.5). Significant synergistic value was recorded by the combination of violacein and clotrimazole. Time-kill assay by the combination of MIC concentration of violacein and azoles recorded that the growth of the T. rubrum was significantly arrested after 4–12 h of treatment. The combination of violacein and azoles leads to the enhanced inhibition of mycelial growth and conidial germination. Moreover combination enhanced the rate of release of intracellular materials. Morphological changes by SEM analysis were also prominent with the combination. A normal human cell line [Foreskin (FS) normal fibroblast] was used to check the cytotoxicity of violacein. Interestingly violacein recorded no cytotoxicity up to 100 μg/ml. The in vitro synergistic effect of violacein and azoles against clinically relevant fungi, T. rubrum, is reported here for the first time. Finally, our findings support the potential use of the violacein as an antifungal agent especially against dermatophytic fungi T. rubrum.

Novel pyrazine analogs of chalcones: synthesis and evaluation of their antifungal and antimycobacterial activity

Infectious diseases, such as tuberculosis and invasive mycoses, represent serious health problems. As a part of our long-term efforts to find new agents for the treatment of these diseases, a new series of pyrazine analogs of chalcones bearing an isopropyl group in position 5 of the pyrazine ring was prepared. The structures of the compounds were corroborated by IR and NMR spectroscopy and their purity confirmed by elemental analysis. The susceptibility of eight fungal strains to the studied compounds was tested. The results have been compared with the activity of some previously reported propyl derivatives. The only strain that was susceptible to the studied compounds was Trichophyton mentagrophytes. It was found that replacing a non-branched propyl with a branched isopropyl did not have a decisive and unequivocal influence on the in vitro antifungal activity against T. mentagrophytes. In vitro activity against Trichophyton mentagrophytes comparable with that of fluconazole was exhibited by nitro-substituted derivatives. Unfortunately, no compound exhibited efficacy comparable with that of terbinafine, which is the most widely used agent for treating mycoses caused by dermatophytes. Some of the prepared compounds were assayed for antimycobacterial activity against M. tuberculosis H₃₇Rv. The highest potency was also displayed by nitro-substituted compounds. The results of the present study are in a good agreement with our previous findings and confirm the positive influence of electron-withdrawing groups on the B-ring of chalcones on the antifungal and antimycobacterial activity of these compounds.

Cutaneous, Subcutaneous and Systemic Mycology

The first description of dermatophytosis was recorded by Celsus, a Roman encyclopaedist who described a suppurative infection of scalp (‘porrigo’ or ‘kerion of Celsus’) in De Re Medicina (30 A.D.). Throughout the middle ages, several descriptions of dermatophytosis were produced where it is described as ‘tinea’. The keratin-destroying moths which made circular holes in the woollen garments are known as Tinea. Due to similarity in the structure of circular lesion of dermatophytosis on the smooth skin with the circular hole made by moth, Cassius Felix introduced the term ‘tinea’ to describe the lesions. In 1806, Alibert used the term ‘favus’ to describe the honey-like exudate in some scalp infections. However, the fungal aetiology of tinea was first detected by Robert Remak, a Polish physician who first observed the presence of hyphae in the crusts of favus. This detection is also a landmark in medical history because this is the first description of a microbe causing a human disease. He himself did not publish his work, but he permitted the reference of his observations in a dissertation by Xavier Hube in 1837. Remak gave all the credits of his discovery to his mentor Schoenlein who first published the fungal etiological report of favus in 1839. He observed the infectious nature of the favus by autoinoculation into his own hands and also successfully isolated the fungus later (1945) and named Achorion schoenleinii (Trichophyton schoenleinii) in honour of his mentor. In 1844, Gruby described the etiologic agent of tinea endothrix, later became known as Trichophyton tonsurans. The genus Trichophyton was created and described by Malmsten (1845) with its representative species T. tonsurans. Charles Robin identified T. mentagrophytes in 1847 and T. equinum was identified by Matruchot and Dassonville in 1898. Raymond Jacques Adrien Sabouraud (France) first compiled the description of Trichophyton in his book (Les Teignes) in 1910 which was based on his observation in artificial culture. The sexual state of dermatophyte was described by Nannizzi (1927). Emmons (1934) first reported the classification of dermatophytes based on vegetative structures and conidia. Gentles (1958) established the successful treatment of tinea capitis with griseofulvin.

Efinaconazole: first global approval

A non-lacquer 10% topical solution of efinaconazole, developed by Valeant Pharmaceuticals International, received its first global approval in Canada in October 2013 for the treatment of onychomycosis. The product is under regulatory review in the US and Japan. The mechanism of anti-fungal activity of efinaconazole, a small-molecule triazole compound, appears to be similar to that of other anti-fungal triazoles, namely ergosterol synthesis inhibition. In particular, it appears to inhibit 14α demethylase, an enzyme involved in the conversion of lanosterol to ergosterol, resulting in secondary degenerative changes. This article summarizes the milestones in the development of efinaconazole leading to this first approval for onychomycosis.

Psychosocial perception of adults with onychomycosis: a blinded, controlled comparison of 1,017 adult Hong Kong residents with or without onychomycosis

Background

A survey was conducted amongst 1,017 Hong Kong residents ages 18 and over to determine their knowledge of fungal nail infections (onychomycosis) and the psychosocial impact of the disease on the relationships, social lives and careers of sufferers.

Methods

The Fungal Nail Perception Survey was conducted by email and online between May 29th and June 10th, 2013. Participants were shown three photographs of people with and without onychomycosis of the toenails. Respondents were asked ten questions (repeated for each picture) to ascertain their perceptions of the people in the pictures. Questions were related to perceptions around the ability of sufferers and non-sufferers to form relationships with others, social activities of sufferers and non-sufferers, perceptions of the effect of the disease on the potential for career success, and awareness of fungal nail disease and health. The sub-population who themselves suffered from onychomycosis were asked about self-perception as well as their perception of others with onychomycosis.

Results

Compared with non-sufferers, survey respondents perceived those with onychomycosis as less likely to be able to form good relationships. They also indicated that they would be more likely to exclude sufferers than non-sufferers from social activities and that they would be more likely to feel uncomfortable when sitting or standing beside an infected person than beside an uninfected person. Respondents perceived people with onychomycosis to be less able to perform well in their chosen career than with someone without onychomycosis. Interestingly, those respondents who themselves were infected felt socially excluded, upset and embarrassed by their infection.

Conclusions

Onychomycosis may lead to stigmatization and social exclusion. Misconceptions of onychomycosis are high and education about the disease needs to be improved. Early recognition and treatment of the disease is essential to avoid complications and improve treatment outcomes, which would lead to reduced psychosocial impact on those with fungal nail infections.

Anti-trichophyton activity of protocatechuates and their synergism with fluconazole

Dermatophytosis and superficial mycosis are a major global public health problem that affects 20–25% of the world's population. The increase in fungal resistance to the commercially available antifungal agents, in conjunction with the limited spectrum of action of such drugs, emphasises the need to develop new antifungal agents. Natural products are attractive prototypes for antifungal agents due to their broad spectrum of biological activities. This study aimed to verify the antifungal activity of protocatechuic acid, 3,4-diacetoxybenzoic, and fourteen alkyl protocatechuates (3,4-dihydroxybenzoates) against Trichophyton rubrum and Trichophyton mentagrophytes and to further assess their activities when combined with fluconazole. Susceptibility and synergism assays were conducted as described in M38-A2 (CLSI), with modifications. Three strains of Trichophyton rubrum and three strains of Trichophyton mentagrophytes were used in this work. The pentyl, hexyl, heptyl, octyl, nonyl, and decyl protocatechuates showed great fungicidal effects, with minimum inhibitory concentration (MIC) values ranging from 0.97 to 7.8 mg/L. Heptyl showed a synergistic activity (FIC index = 0.49), reducing the MIC of fluconazole by fourfold. All substances tested were safe, especially the hexyl, heptyl, octyl, and nonyl compounds, all of which showed a high selectivity index, particularly in combination with fluconazole. These ester associations with fluconazole may represent a promising source of prototypes in the search for anti-Trichophyton therapeutic agents.

Trichophyton rubrum osteomyelitis after calcaneus external fixation pin stabilization of a pilon fracture

Fungal organisms are an uncommon cause of osteomyelitis, and no dermatophyte osteomyelitis infections have been reported in published studies. We present the case of Trichophyton rubrum osteomyelitis of the calcaneus. Our patient initially presented with a pilon fracture requiring temporary external fixation while awaiting definitive fixation. From our review of the published data, the present case is the first of this type of fungal osteomyelitis to be reported. The patient was evaluated for a left neck mass during his hospitalization that was later found to be consistent with salivary duct carcinoma of the tail of the parotid gland. A left neck dissection and superficial excision of the parotid gland was performed after fixation of his pilon fracture. Subsequently, he developed an increasing lucency in the calcaneus and symptoms of pain and erythema months after the calcaneus pin had been removed. The osteomyelitis was treated with surgical debridement and 3 months of itraconazole once cultures had definitively grown T. rubrum.

The prevalence of onychomycosis in the global population: a literature study

BACKGROUND

Onychomycosis is a common disorder, and high prevalence figures are commonly cited in the literature.

OBJECTIVES

Evaluate the prevalence of onychomycosis based on published studies.

METHODS

Relevant studies were identified in Medline by using specific search criteria.

RESULTS

Eleven population-based and 21 hospital-based studies were identified. The mean prevalence in Europe and North America was 4.3% [95% Confidence Interval (CI): 1.9-6.8] in the population-based studies, but it was 8.9% (95% CI: 4.3-13.6) for the hospital-based studies. Both population-based and hospital-based studies showed that onychomycosis is more common in toenails and is seen more frequently in males. The main causative agent was a dermatophyte in 65.0% (95% CI: 51.9-78.1) of the cases. Trichophyton rubrum was the single most common fungus and was cultured on average in 44.9% of the cases (95% CI: 33.8-56.0). Moulds were found on average in 13.3% (95% CI: 4.6-22.1) and yeasts in 21.1% (95% CI: 11.0-31.3).

LIMITATIONS

We may not have been able to locate all studies.

CONCLUSIONS

Onychomycosis is a common disorder, but it may not be as common as cited in the literature, because hospital-based studies might overestimate the prevalence of onychomycosis. It is more frequent in males, and toenails are more commonly affected. Dermatophytes, particularly T. rubrum, are the main causative agents.

Laser therapy of onychomycosis

Since 2010 the FDA has approved laser systems as capable of producing a "temporary increase in clear nails" in patients with onychomycosis. Fungal eradication is probably mediated by heat in infrared laser systems; their efficacy has been confirmed thermographically, histologically and in electron microscopy. Another approach to decontaminate the nail organ is to disrupt fungi and spores by q-switched pulse applications. Recently specific combinations of wavelengths have been tested for their ability to disrupt the mitochondrial transmembrane potential at physiological temperatures by generating ATP and ROS. While clinically extremely high clearance rates of approximately 87.5-95.8 % have been reported, in-vitro investigations have failed to confirm the clearance. The variety of systems and advised parameters hampers a systematic evaluation. Recommendations for safe and practical treatment protocols, informed consent items, and combination with conventional treatment options are all areas of active work. Currently there is a lack of data concerning the long-term efficacy of laser therapy of onychomycosis; certified treatment protocols are needed.

The prevalence of onychomycosis in psoriatic patients: a systematic review

We systematically reviewed all available literature concerning the prevalence of onychomycosis in patients with nail psoriasis and the distribution of pathogens causing onychomycosis in this specific group of patients. Databases searched were Pubmed, EMBASE and the Cochrane Controlled Clinical Trial Register. All studies reporting on the prevalence of onychomycosis in nail psoriasis were obtained, and quality assessment was determined by the STrengthening the Reporting of OBservational studies in Epidemiology checklist. Literature search revealed 720 studies, of which 10 studies met the inclusion criteria. The major limitation of the review was the heterogeneity of the included studies, which prevented the possibility to conduct a meta analysis. However, the average prevalence of 18.0% of onychomycosis in psoriatic patients seems to be increased when compared with control groups and literature on healthy population, even though the ultimate evidence remains lacking. As in the literature hypothesized shift in causative agents from dermatophytes to yeasts and/or moulds could not be confirmed. The clinical consequence of the relatively high prevalence of onychomycosis in psoriasis may be a general advice to rule out onychomycosis or concomitant onychomycosis in these patients with (suspected) nail psoriasis. This advice is stressed by the relative simplicity of treating the contribution of onychomycosis in the nail dystrophy but also the fact that nail psoriasis mostly is treated by immunosuppressive drugs, like steroids, methotrexate or biologics which may aggravate mycotic nail infections.