Clinical Forms of Dermatophytosis (Ringworm Infection)

Dermatophyte infection: from fungal pathogenicity to host immune responses

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

Advances of liposomal mediated nanocarriers for the treatment of dermatophyte infections

Due to the adverse effects associated with long-term administration of antifungal drugs used for treating dermatophytic lesions like tinea unguium, there is a critical need for novel antifungal therapies that exhibit improved absorption and minimal adverse effects. Nanoformulations offer a promising solution in this regard. Topical formulations may penetrate the upper layers of the skin, such as the stratum corneum, and release an appropriate amount of drugs in therapeutic quantities. Liposomes, particularly nanosized ones, used as topical medication delivery systems for the skin, may have various roles depending on their size, lipid and cholesterol content, ingredient percentage, lamellarity, and surface charge. Liposomes can enhance permeability through the stratum corneum, minimize systemic effects due to their localizing properties, and overcome various challenges in cutaneous drug delivery. Antifungal medications encapsulated in liposomes, including fluconazole, ketoconazole, croconazole, econazole, terbinafine hydrochloride, tolnaftate, and miconazole, have demonstrated improved skin penetration and localization. This review discusses the traditional treatment of dermatophytes and liposomal formulations. Additionally, promising liposomal formulations that may soon be available in the market are introduced. The objective of this review is to provide a comprehensive understanding of dermatophyte infections and the role of liposomes in enhancing treatment.

Cutaneous Fungal Infections Caused by Dermatophytes and Non-Dermatophytes: An Updated Comprehensive Review of Epidemiology, Clinical Presentations, and Diagnostic Testing

Cutaneous fungal infection of the skin and nails poses a significant global public health challenge. Dermatophyte infection, mainly caused by Trichophyton spp., is the primary pathogenic agent responsible for skin, hair, and nail infections worldwide. The epidemiology of these infections varies depending on the geographic location and specific population. However, epidemiological pattern changes have occurred over the past decade. The widespread availability of antimicrobials has led to an increased risk of promoting resistant strains through inappropriate treatment. The escalating prevalence of resistant Trichophyton spp. infections in the past decade has raised serious healthcare concerns on a global scale. Non-dermatophyte infections, on the other hand, present even greater challenges in terms of treatment due to the high failure rate of antifungal therapy. These organisms primarily target the nails, feet, and hands. The diagnosis of cutaneous fungal infections relies on clinical presentation, laboratory investigations, and other ancillary tools available in an outpatient care setting. This review aims to present an updated and comprehensive analysis of the epidemiology, clinical manifestations, and diagnostic testing methods for cutaneous fungal infections caused by dermatophytes and non-dermatophytes. An accurate diagnosis is crucial for effective management and minimizing the risk of antifungal resistance.

Dermatopathology and the Diagnosis of Fungal Infections

Diagnosis of superficial/cutaneous fungal infections from skin, hair and nail samples is generally achieved using microscopy and culture in a microbiology laboratory, however, any presentation that is unusual or subcutaneous is sampled by taking a biopsy. Using histological techniques a tissue biopsy enables a pathologist to perform a full examination of the skin structure, detect any inflammatory processes or the presence of an infectious agent or foreign body. Histopathological examination can give a presumptive diagnosis while a culture result is pending, and may provide valuable diagnostic information if culture fails. This review demonstrates how histopathology contributes to the diagnosis of fungal infections from the superficial to the life threatening.

Assessing the efficacy and safety of Unani pharmacopoeial formulations in dermatophytosis (quba) - a randomized controlled trial

OBJECTIVES

The recent trends of rising unresponsive cases of dermatophytosis to conventional therapies pose a challenge in clinical practice. Unani medicine offers effective treatment for dermatophytosis. This study aimed to evaluate the efficacy and safety of the Unani herbo-mineral preparations Qurs-e-Asfar (QA) and Rogan-e-Narjeel (RN) in dermatophytosis.

METHODS

This was a randomized, active-controlled and open-label clinical study. The participants diagnosed with dermatophytosis (n=78) randomized into treatment group (n=40) receiving oral QA (778 mg twice a day) and topical RN and control group (n=38) receiving oral Itraconazole (100 mg/day) and topical Terbinafine hydrochloride (1%) for 6 weeks.

RESULTS

We found post-treatment improvement in itching by 86.3% vs. 78% (treatment vs. control group), erythema by 96.4% vs. 94.3%, scaling by 93% vs. 92.2% and peripheral raised margins by 82.3% vs. 81%. Furthermore, this study showed that the differences in the mean Total Signs and Symptoms Score (TSSS) and positive KOH mount were clinically and statistically significant (p<0.05) in both the groups. On comparing inter group, the differences in mean TSSS (p=0.07) and positive KOH mount (p=0.717) were found statistically insignificant.

CONCLUSIONS

This study concludes that the formulations QA and RN were effective and safe in the treatment of dermatophytosis.

Survey on Dermatophytes Isolated from Animals in Switzerland in the Context of the Prevention of Zoonotic Dermatophytosis

Most inflammatory dermatophytoses in humans are caused by zoophilic and geophilic dermatophytes. Knowledge of the epidemiology of these fungi in animals facilitates the prevention of dermatophytosis of animal origin in humans. We studied the prevalence of dermatophyte species in domestic animals in Switzerland and examined the effectiveness of direct mycological examination (DME) for their detection compared to mycological cultures. In total, 3515 hair and skin samples, collected between 2008 and 2022 by practicing veterinarians, were subjected to direct fluorescence microscopy and fungal culture. Overall, 611 dermatophytes were isolated, of which 547 (89.5%) were from DME-positive samples. Cats and dogs were the main reservoirs of Trichophyton mentagrophytes and Microsporum canis, whereas Trichophyton benhamiae was predominantly found in guinea pigs. Cultures with M. canis significantly (p < 0.001) outnumbered those with T. mentagrophytes in DME-negative samples (19.3% versus 6.8%), possibly because M. canis can be asymptomatic in cats and dogs, unlike T. mentagrophytes, which is always infectious. Our data confirm DME as a reliable, quick, and easy method to identify the presence of dermatophytes in animals. A positive DME in an animal hair or skin sample should alert people in contact with the animal to the risk of contracting dermatophytosis.

Risk factors of dermatophytosis among Korean adults

Dermatophytosis includes all fungal infections caused by dermatophytes in humans. Some risk factors for the development of subtypes of dermatophytosis have been studied; however, large-scale epidemiologic studies on risk factors for total dermatophytosis are scarce. We investigated the risk factors of dermatophytosis using a nationwide study. Total 4,532,655 subjects with dermatophytosis aged between 20 and 40 years were examined using data from the Korean National Health Insurance Service from 2009 to 2018. Women showed a lower risk of development of dermatophytosis compared to men [hazard ratio (HR) 0.848; 95% confidence interval (CI) 0.843–0.853]. Subjects with elevated waist circumference (HR 1.057; 95% CI 1.048–1.065), heavy drinking (HR 1.053; 95% CI 1044–1.061), engaging in mild-to-heavy exercise (HR 1.071; 95% CI 1.064–1.077) had a higher risk of dermatophytosis. In addition, subjects with body mass index (BMI) of more than 30 kg/m² exhibited a higher risk of dermatophytosis (HR 1.36; 95% CI 1.342–1.378) compared to those with BMIs in the range of 18.5–23 kg/m². In this study, the risk of developing dermatophytosis significantly increased in individuals with elevated waist circumference or high BMI. Lifestyle modifications, including weight management, are suggested to be important in preventing dermatophytosis.

Prevalence and Risk Factors of Zoonotic Dermatophyte Infection in Pet Rabbits in Northern Taiwan

Dermatophytes are the group of keratinophilic fungi that cause superficial cutaneous infection, which traditionally belong to the genera Trichophyton, Microsporum, and Epidermophyton. Dermatophyte infection is not only a threat to the health of small animals, but also an important zoonotic and public health issue because of the potential transmission from animals to humans. Rabbit dermatophytosis is often clinically identified; however, limited information was found in Asia. The aims of this study are to investigate the prevalence and to evaluate the risk factors of dermatophytosis in pet rabbits in Northern Taiwan. Between March 2016 and October 2018, dander samples of pet rabbits were collected for fungal infection examination by Wood’s lamp, microscopic examination (KOH preparation), fungal culture, and PCR assay (molecular identification). Z test and Fisher’s exact test were performed to evaluate the potential risk factors, and logistic regression analysis was then performed to build the model of risk factors related to dermatophyte infection. Of the collected 250 dander samples of pet rabbits, 29 (11.6%) samples were positive for dermatophytes by molecular identification. In those samples, 28 samples were identified as the T. mentagrophytes complex and 1 sample was identified as M. canis. Based on the results of the Firth’s bias reduction logistic analyses, animal source (rabbits purchased from pet shops) and number of rearing rabbits (three rabbits or more) were shown as the main risks for dermatophyte infection in the pet rabbits in Taiwan. The results of the present study elucidate the prevalence of rabbit dermatophyte infection, pathogens, and risk factors in Taiwan, and provide an important reference for the prevention and control of rabbit dermatophytosis.

Potential of propolis antifungal activity for clinical applications

The high incidence of skin diseases of microbial origin along with the widespread increase of microbial resistance demand for therapeutic alternatives. Research on natural compounds has been opening new perspectives for the development of new therapies with health positive impacts. Propolis, a resinous mixture produced by honeybees from plant exudates, is widely used as a natural medicine since ancient times, mainly due to its antimicrobial properties. More recently, antioxidant, anti-tumor, anti-inflammatory, hepatoprotective and immunomodulatory activities were also reported for this natural product, highlighting its high potential pharmacological interest. In the present work, an extensive review of the main fungi causing skin diseases as well as the effects of natural compounds, particularly propolis, against such disease-causing microorganisms was organized and compiled in concise handy tables. This information allows to conclude that propolis is a highly effective antimicrobial agent suggesting that it could be used as an alternative skin treatment against pathogenic microorganisms and also as a cosmeceutic component or as a source of bioactive ingredients.

Potential Inhibitors of CYP51 Enzyme in Dermatophytes by Red Sea Soft Coral Nephthea sp.: In Silico and Molecular Networking Studies

In this study, the n-hexane fraction of soft coral Nephthea sp. gathered from the Red Sea was evaluated for its antidermatophyte activity. The antidermatophyte activity was performed versus different fungi, including Microsporum canis, Trichophyton gypseum, and Microsporum mentagrophytes, using a broth microdilution method. The n-hexane fraction showed minimum inhibitory concentrations (MICs) against the tested dermatophytes of 104.2 ± 20.8, 125 ± 0.0, and 83.33 ± 20.83 μg/mL respectively. The chemical constitution of the lipoidal matter (n-hexane fraction) was characterized by gas chromatography coupled with a mass spectrometer (GC-MS). The unsaponifiable fraction (USAP) of Nephthea sp. showed relative percentages of hydrocarbons and vitamins of 69.61% and 3.26%, respectively. Moreover, the percentages of saturated and unsaturated fatty acids were 53.67% and 42.05%, respectively. In addition, a molecular networking study (MN) of the GC-MS analysis performed using the Global Natural Products Social Molecular Networking (GNPS) platform was described. The molecular docking study illustrated that the highest binding energy score for spathulenol toward the CYP51 enzyme was -8.3674 kcal/mol, which predicted the mode of action of the antifungal activity, and then the results were confirmed by the inhibitory effect of Nephthea sp. against CYP51 with an IC₅₀ value of 12.23 μg/mL. Our results highlighted the antifungal potential of Nephthea sp. metabolites.

Tinea incognito "mask"erading as allergic contact dermatitis due to COVID-19 facial covering in children

We present three children with tinea incognito initially misdiagnosed as allergic contact dermatitis to face masks. All three patients presented with pruritic erythematous patches and plaques across the malar cheek and nose. This case series suggests that clinicians should keep a broad differential when evaluating mask-related facial dermatoses in children.

The Changing Face of Epidemiology of Dermatophytoses in Chinese Mainland: A 30 years Nationwide Retrospective Study from 1991 to 2020

BACKGROUND

Dermatophytoses are the most common infectious skin disease. Its epidemiology varies in different countries and regions, and its prevalence in China is still unknown.

OBJECTIVES

We aimed to reveal the epidemiological features of dermatophytoses in Chinese mainland in the past thirty years.

METHODS

From 1991 to 2020, a 30-year retrospective epidemiological study was carried out. All published literatures containing dermatophytoses and dermatophytes were collected and analyzed.

RESULTS

A total of more than 180,000 cases in 124 articles from more than 100 hospitals were included and analyzed. Among dermatophytoses, tinea cruris (24.92%) was the predominant clinical type, followed by tinea pedis (22.97%) and tinea corporis (18.12%). In recent 10 years, tinea pedis (25.40%) was more common than tinea cruris (22.39%) and became the most common infection. Among dermatophytes, T. rubrum (69.48%) has always been the most common isolates, followed by T. mentagrophytes (16.45%) and M. canis (8.09%). Other species were found below 3%. In superficial mycoses, dermatophytes accounted for 75.52%, higher than that of yeasts/yeast-like (21.83%) and molds (2.65%). The prevalence of tinea capitis was lower in economically developed eastern region than that in central and western regions. Tinea cruris was more common in warm zones than cold zones.

CONCLUSIONS

The top three dermatophytoses are tinea cruris, tinea pedis and tinea corporis, while the top three dermatophytes are T. rubrum, T. mentagrophytes and M. canis. The distribution of dermatophytoses may be influenced by socioeconomic status and geographical-meteorological conditions.

Discovery of New Trichophyton Members, T. persicum and T. spiraliforme spp. nov., as a Cause of Highly Inflammatory Tinea Cases in Iran and Czechia

Pathogens from the Trichophyton benhamiae complex are one of the most important causes of animal mycoses with significant zoonotic potential. In light of the recently revised taxonomy of this complex, we retrospectively identified 38 Trichophyton isolates that could not be resolved into any of the existing species. These strains were isolated from Iranian and Czech patients during molecular epidemiological surveys on dermatophytosis and were predominantly associated with highly inflammatory tinea corporis cases, suggesting possible zoonotic etiology. Subsequent phylogenetic (4 markers), population genetic (10 markers), and phenotypic analyses supported recognition of two novel species. The first species, Trichophyton persicum sp. nov., was identified in 36 cases of human dermatophytosis and one case of feline dermatophytosis, mainly in Southern and Western Iran. The second species, Trichophyton spiraliforme sp. nov., is only known from a single case of tinea corporis in a Czech patient who probably contracted the infection from a dog. Although the zoonotic sources of infections summarized in this study are very likely, little is known about the host spectrum of these pathogens. Awareness of these new pathogens among clinicians should refine our knowledge about their poorly explored geographic distribution. IMPORTANCE In this study, we describe two novel agents of dermatophytosis and summarize the clinical manifestation of infections. These new pathogens were discovered thanks to long-term molecular epidemiological studies conducted in Czechia and Iran. Zoonotic origins of the human infections are highly probable, but the animal hosts of these pathogens are poorly known. Further research is needed to refine our knowledge about these new dermatophytes.

Efficacy of cyclic lipopeptides obtained from Bacillus subtilis to inhibit the growth of Microsporum canis isolated from cats

Background and aim

Microsporum canis (M. canis) is a dermatophyte fungal pathogen that causes ringworms. Cats are considered to be a dominant reservoir host enabling M. canis transmission to humans. The concerns of dermatophyte resistance were raised among the usage of antifungal drugs to treat the ringworm. This study aimed to evaluate the fungal activity of cyclic lipopeptides (CLPs) obtained from Bacillus subtilis (B. subtilis) as an alternative method for the inhibition of M. canis growth.

Materials and methods

The culture plate of M. canis from confirmed cats with ringworm infection was provided. The purification of CLP extract, fengycin, iturin A, and surfactin was carried out from B. subtilis by preparative thin-layer chromatography (PTLC) coupled with solid-phase extraction (SPE) methods. Half-maximal effective concentration (EC₅₀) and agar well diffusion assays were performed to determine the efficacy of Bacillus CLP extract, fengycin, iturin A, and surfactin to inhibit the growth of M. canis isolated from cats.

Results

All purified Bacillus substances displayed antifungal activity to control the growth of M. canis when compared with 80% ethanol (control). EC₅₀ values for CLP extract, fengycin, iturin A, and surfactin were 0.23, 0.05, 0.17, and 0.08 mg/mL, respectively. In agar well diffusion assay, the ability of CLP extract, fengycin, iturin A, and surfactin on fungal inhibition had no statistically significant difference at 24 and 48 h after treatment (p < 0.05). However, CLP extract showed a statistically significant difference on M. canis inhibition at 62.21% followed by surfactin with 59.04% at 72 h after treatment.

Conclusion

In vitro, Bacillus CLPs revealed an inhibitory effect on M. canis growth which is a zoonotic pathogen that causes ringworms. This study suggests an alternative approach to control the growth of M. canis using substances obtained from B. subtilis as a biomedicine agent with antifungal activity.

Antifungal Combinations in Dermatophytes

Dermatophytes are the most common cause of fungal infections worldwide, affecting millions of people annually. The emergence of resistance among dermatophytes along with the availability of antifungal susceptibility procedures suitable for testing antifungal agents against this group of fungi make the combinatorial approach particularly interesting to be investigated. Therefore, we reviewed the scientific literature concerning the antifungal combinations against dermatophytes. A literature search on the subject performed in PubMed yielded 68 publications: 37 articles referring to in vitro studies and 31 articles referring to case reports or clinical studies. In vitro studies involved over 400 clinical isolates of dermatophytes (69% Trichophyton spp., 29% Microsporum spp., and 2% Epidermophyton floccosum). Combinations included two antifungal agents or an antifungal agent plus another chemical compound including plant extracts or essential oils, calcineurin inhibitors, peptides, disinfectant agents, and others. In general, drug combinations yielded variable results spanning from synergism to indifference. Antagonism was rarely seen. In over 700 patients with documented dermatophyte infections, an antifungal combination approach could be evaluated. The most frequent combination included a systemic antifungal agent administered orally (i.e., terbinafine, griseofulvin, or azole-mainly itraconazole) plus a topical medication (i.e., azole, terbinafine, ciclopirox, amorolfine) for several weeks. Clinical results indicate that association of antifungal agents is effective, and it might be useful to accelerate the clinical and microbiological healing of a superficial infection. Antifungal combinations in dermatophytes have gained considerable scientific interest over the years and, in consideration of the interesting results available so far, it is desirable to continue the research in this field.

Controlling Growth of Multidrug-Resistant Staphylococci Isolated from Sports Mats: A Report from the Golestan Province, Iran

Background: Gyms are among the places where various human infections can spread. One of the most important strategies to prevent infection spread among athletes is the use of strong and effective disinfectants. Objectives: The aim of this study was to evaluate and compare the antiseptic properties of chlorhexidine gluconate and pomegranate peel extract on staphylococcal isolates from sports mats. Methods: This descriptive-analytical study was performed on 22 Staphylococcus aureus, and Staphylococcus epidermidis isolates from a total of 105 sports mat samples. After identification of multi-drug resistant (MDR) staphylococcal isolates, the antimicrobial effect of chlorhexidine gluconate 20% and pomegranate peel extract was evaluated by broth microdilution according to the instructions of the Clinical and Laboratory Standards Institute. Results: Overall, 14 (66.7%) S. aureus and 8 (28.6%) S. epidermidis isolates resistant to azithromycin, linezolid, ciprofloxacin, vancomycin, and aztreonam were reported as MDR strains. The minimum inhibitory concentration (MIC) of chlorhexidine gluconate, which inhibited the growth of 90% of MDR S. aureus isolates was 250 μg/mL, which was 4-fold lower than the MIC of pomegranate peel extract (MIC90 ≥ 500μg/mL) and 2-fold lower against MDR S. epidermidis isolates (MIC90 ≤ 125 μg/mL). The MIC of chlorhexidine gluconate and pomegranate peel extract against S. aureus isolates differed significantly (P = 0.037). Conclusions: Compared to pomegranate peel extract, chlorhexidine gluconate has a higher antibacterial effect on MDR staphylococcal isolates from sports mats. Further research is required to verify the efficacy of this biocide for disinfection of gyms and sports clubs.

In Vitro Antifungal Activity of Green Synthesized Silver Nanoparticles in Comparison to Conventional Antifungal Drugs Against Trichophyton Interdigitale, Trichophyton Rubrum and Epidermophyton Floccosum

BACKGROUND

Dermatophytosis is a globally distributed fungal infection. Treatment failure and relapse is common in this disease. Silver nanoparticles are known for their promising antimicrobial activity. The aim of this study was to determine the antifungal activity of these nanoparticles against common dermatophyte species.

METHODS

A set of 30 molecularly identified dermatophytes including Trichophyton interdigitale (n=10), Trichophyton rubrum (n=10), and Epidermophyton floccosum (n=10) were used in this study. Green synthesized silver nanoparticles using chicory (Cichorium intybus) were tested for their antifungal activity in comparison to fluconazole, itraconazole and terbinafine. Interspecies differences in minimum inhibitory concentrations of antifungal drugs and silver nanoparticles were tested using Kruskal-Wallis test in SPSS software version 21.

RESULTS

The highest minimum inhibitory concentrations (MICs) among antifungal drugs were observed for fluconazole [range: 4-64 μg/mL, geometric mean (GM) =17.959 μg/mL], followed by itraconazole (range: 0.008-0.5, GM= 0.066) and terbinafine (range: 0.004-0.25 μg/mL, GM=0.027 μg/mL). Silver nanoparticles showed potent antifungal activity against all dermatophyte isolates with MICs (range: 0.25-32 μg/mL, GM=4.812 μg/mL) higher than those of itraconazole and terbinafine, but lower than fluconazole. MIC values of silver nanoparticles demonstrated significant differences between species (P=0.044), with E. floccosum having the highest MICs (GM=9.849 μg/mL) compared to T. interdigitale (GM=3.732 μg/mL) and T. rubrum (GM=3.031 μg/mL).

CONCLUSION

Silver nanoparticles demonstrated promising anti-dermatophyte activity against the studied dermatophytes. Due to their wide-spectrum activity against other fungal and bacterial pathogens, they could be a potential choice, at least in the case of cutaneous and superficial infections.

Conventional and natural compounds for the treatment of dermatophytosis

Dermatophytes are a group of pathogenic fungi that exclusively infect the stratum corneum of the skin, nails, and hair, causing dermatophytosis. Superficial skin infections caused by dermatophytes have increased in the last decades. There are conventional antifungals that treat these infections, such as terbinafine, fluconazole, and others. However, the limitations of these treatments (resistance, side effects and toxicity) along with the increasing over-prescription, the misuse of these antifungals and the high treatment costs led to the search for new, alternative, natural-based antifungal drugs. These have multiple mechanisms of action, which works to their advantage, making it difficult for a fungus to create resistance mechanisms against all of them at the same time. The main objective of this work is to provide a state-of-the-art review on dermatophytes, dermatophytosis, and the existing treatments, both conventional and natural, such as chitosan and essential oils.

Superficial mycoses, a matter of concern: Global and Indian scenario-an updated analysis

Superficial mycoses of skin, nails and hair are among the common fungal infections. They are caused by dermatophytes, non-dermatophyte moulds, yeasts and yeast-like fungi. Such fungal infections are widespread all over the world and are predominant in tropical as well as subtropical regions. Environmental factors, such as warm, humid and pitiable hygienic conditions, are conducive for their growth and proliferation. Although it does not cause mortality, it is known to be associated with excessive morbidity which may be psychological or physical. This affects the quality of life of the infected individuals which leads to a negative impact on their occupational, emotional and social status. Such infections are increasing on a global scale and, therefore, are of serious concern worldwide. This review article covers the global and Indian scenario of superficial mycoses taking into account the historical background, aetiological agents, prevalence, cultural and environmental factors, risk factors, pathogenesis and hygienic practices for the prevention of superficial mycoses.

Plant-derived isoquinoline alkaloids that target ergosterol biosynthesis discovered by using a novel antifungal screening tool

The ergosterol pathway is a prime antifungal target as it is required for fungal survival, yet is not involved in human homeostasis. Methods to study the ergosterol pathway, however, are often time-consuming. The minimum inhibitory concentration (MIC) assay is a simple research tool that determines the lowest concentration at which a novel antimicrobial is active in vitro with limited scope to determine the mechanism of action for a drug. In this study, we show that by adding hydrogen peroxide, an oxidative stressor, or glutathione (GSH), an antioxidant, to modify a commonly performed MIC assay allowed us to screen selectively for new antifungal drugs that target ergosterol biosynthesis in fungi. A human pathogen and dermatophyte, Microsporum gypseum, was used as a test organism. When exposed to ergosterol targeting drugs, the hydrogen peroxide treatment significantly decreased fungal survival by reducing ergosterol in the cell wall, whereas GSH increased survival of M. gypseum. Further, by performing a series of experiments with M. gypseum and Trichophyton rubrum, it was determined that the oxidative stress from hydrogen peroxide causes cell death at different developmental stages based on fungal species. These findings allow us to describe a simple, high-throughput method for simultaneously screening new antifungal drugs for activity and effects on the ergosterol pathway. By using this tool, two isoquinoline alkaloids were discovered to be potent inhibitors of ergosterol biosynthesis in vitro by reducing the amount of ergosterol without affecting the expression of 1,3-β-glucan. Both compounds also significantly reduced the severity of acanthosis, hyperkeratosis, spongiosis and dermal edema in vivo.

Host immune responses in dermatophytes infection

Dermatophytosis is a skin infection caused by keratinophilic, filamentous fungi. These are highly prevalent, common mycoses, affecting approximately 20% of the population. These fungi invade the stratum corneum, and other keratinised tissues, like nails and hair, where they grow by secreting enzymes and degrading keratin to obtain nutrients. Clinical presentation is variable and may depend on many factors, such as the infection site, the host's immunity and the dermatophyte's virulence. Generally, patients with acute superficial dermatophytosis mount cell-mediated immune responses. However, those suffering from chronic or recurrent infections are unable to develop this response, for reasons yet unknown. Several reports have described severe and occasionally life-threatening invasive diseases (deep dermatophytosis) associated with genetic mutations in the innate immunity-associated molecule CARD9, displaying the need to better understand its immune response. These dermatoses have substantial clinical consequences, producing chronic and difficult to treat skin lesions. They also lead to a decline in the patient's quality of life and impact their self-esteem. This review summarises findings on the immune response against dermatophytes.

The best type of inoculum for testing the antifungal drug susceptibility of Microsporum canis: In vivo and in vitro results

BACKGROUND

Data correlating in vitro drug susceptibility of Microsporum canis with clinical outcomes of its infections are lacking as well as the most suitable inoculum and incubation time in broth microdilution assays.

OBJECTIVES AND METHODS

Microsporum canis strains were collected from animal hosts that tested positive (Group I; n = 13) and negative (Group II; n = 14) to this pathogen following itraconazole (ITC) therapy. In vitro ITC susceptibility was assessed according to the Clinical Laboratory Standards Institute (CLSI M38-A2) methodology using conidia, hypha-conidia and arthroconidia at 3 and 7 days of incubation in order to assess the most suitable inoculum and incubation time. Successively, ketoconazole (KTC), voriconazole (VRC), terbinafine (TRB), posaconazole (PSZ), fluconazole (FLC) and griseofulvin (GRI) susceptibilities were assessed using the chosen inoculum.

RESULTS

The MIC values of ITC after three-day incubation were equal than those recorded after 7-day incubation. Itraconazole MICs were ≤1 μg/mL for strains from Group II and >1 μg/mL for those of Group II only when conidia were used. All strains showed high susceptibility to VRC, POS, TEB and low susceptibility to ITC, KTC, GRI and FLC regardless of the source and incubation time.

CONCLUSIONS AND CLINICAL IMPORTANCE

Results suggest that correlation between the in vitro results and clinical outcome was observed only by incubating conidia for 3 days at 30 ± 2°C. These conditions might be most suitable to assess in vitro susceptibility of M. canis and assist in determining the occurrence of drug resistance and cross-resistance phenomena.

Preparation, and Assessment of Antidermatophyte Activity of Miconazole-Urea Water-Soluble Film

Cutaneous mycoses, particularly tinea pedis caused by Trichophyton rubrum, are commonly known infections in humans. They are still considered as a major public health problem worldwide affecting the quality of life due to prolonged period of treatment and development of drug resistance, which leads to recurrence of infections. The objective of our study was to assess the effectiveness of miconazole in the presence and absence of urea, as a penetration enhancer, against T. rubrum and to formulate both of them in a water-soluble film to be applied topically for the purpose of treating tinea pedis caused by this fungus. Drug combination revealed synergism where miconazole minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) (0.5 and 1 mg/L) were considerably declined to 0.001 and 0.004 mg/L, respectively, when combined with 20% urea. This enhanced drug interaction activity against the test strain was explained by the alterations raised on the morphology and ultrastructures observed microscopically. Minimal fungicidal dose of miconazole/urea combination displayed plasmolysis and shrink cytoplasm; however, necrotic cells with punctured walls and degraded cytoplasmic content were observed at high fungicidal dose. Water-soluble films, prepared using increasing values of miconazole MFC and urea, were transparent, smooth, uniform, and flexible. Their physicochemical characters showed homogeneity in weight, thickness, drug content, and folding endurances with normal surface pH values, indicating the reproducibility of the preparation method. The novel simulation model for the film mechanism of action supported the idea and the suggested application method of the new dosage form. Evaluation of these films was carried in vitro using disk diffusion assay as well as in vivo using guinea pig dermatophytosis model. The in vitro assessment revealed an increase in the inhibition zone diameters in a concentration-dependent manner upon using 10 or 20% of urea combined with miconazole. In vivo test showed that combination of 0.004 mg/L miconazole with 20% urea (M + U20) showed the highest efficacy percentage (95.83%), which was statistically superior to the infected untreated control (p < 0.001) in fungal burden reduction as well as improvement in clinical scores (p < 0.001). This work supports the hypothesis and suggests a new promising dosage form for the treatment of T. rubrum infections.

Recent advances in the diagnosis of dermatophytosis

Dermatophytosis is a disease of global significance caused by pathogenic keratinolytic fungi called dermatophytes in both animals and humans. The recent taxonomy of dermatophytes classifies them into six pathogenic genera, namely Microsporum, Trichophyton, Epidermophyton, Nannizzia, Lophophyton and Arthroderma. It is because of the delayed diagnostic nature and low accuracy of dermatophyte detection by conventional methods that paved the path for the evolution of molecular diagnostic techniques, which provide the accurate and rapid diagnosis of dermatophytosis for an appropriate, timely antifungal therapy that prevents the nonspecific over-the-counter self-medication. This review focuses on the importance of rapid and accurate diagnosis of dermatophytosis, limitations of conventional methods, selection of targets in diagnosis, and factors affecting sensitivity and specificity of various molecular diagnostic technologies in the diagnosis of dermatophytosis. Generally, all the molecular techniques have a significant edge over the conventional methods of culture and microscopy in the dermatophytosis diagnosis. However, in mycology laboratory, the suitability of any molecular diagnostic technique in the diagnosis of dermatophytosis is driven by the requirement of time, economy, complexity, the range of species spectrum detected and the scale of diagnostic output required. Thus, various choices involved in the pursuit of a diagnosis of dermatophytosis are determined by the available conditions and the facilities in the laboratory.

In vitro models of dermatophyte infection to investigate epidermal barrier alterations

Fungal infections of the skin, known as dermatophytoses, are initiated at the epidermal barrier and lead to dysfunctions of the stratum corneum and cornified skin appendages. Dermatophytosis affects a significant part of the human population and, despite the availability of effective treatments, its prevalence is still increasing. Numerous dermatophyte species are able to induce lesions in both animals and humans, with different clinical pictures and host inflammatory responses. The understanding of the infectious process and of tissue responses has been impeded by discrepancies between observations in vivo or in research models. Indeed, cells cultured as monolayers do not undergo the keratinization process required to study the adherence and invasion of dermatophytes. Animal models lack relevance to study human dermatophytosis because of species-specific differences in the development of lesions and inflammatory responses. This review focuses on the recent development of cultured human skin equivalents, which partly overcomes those limitations and allows improved understanding of the pathogenesis of dermatophytosis in human being, especially the impacts of infection on epidermal barrier integrity.

Host- and pathogen-dependent susceptibility and predisposition to dermatophytosis

Dermatophytes are a highly specialized group of keratinophilic and keratinolytic filamentous fungi causing a ringworm disease called dermatophytosis or superficial mycoses. Although dermatophyte infections do not threaten the host's life, they lower its quality in humans by causing discomfort related to cosmetic problems and through their epidemiological significance, whereas in farm animals they are responsible for economic losses and constitute a source of the spread of spores. Evidence from countless observational studies that have been conducted over the last 90 years indicates that dermatophytes infect humans of every age, race, gender and socioeconomic status with strikingly high rates, as well as both farmed and wild animals in various health conditions and with various epidemiological statuses. However, the prevalence of superficial fungal infections is highly variable, since it depends on several parameters associated with the infected individual and the dermatophyte, their mutual interactions, and epidemiological and geographical factors. The curious disparity in dermatophyte infection patterns has prompted many investigators to search for a link between the host, the host's predispositions and susceptibility to the disease, and the dermatophyte species and virulence. Thus, the question arises as to whether, in addition to the generally recognized factors predisposing hosts to diseases, there are some other predispositions to dermatophyte infections in a species-specific host. In this review, we describe recent findings about the mechanism of dermatophyte infections, focusing on the adaptation of the fungi to the host and conditions predisposing each side to the disease.

A prospective study of the epidemiological and clinical patterns of recurrent dermatophytosis at a tertiary care hospital in India

Background

Recurrent and clinically unresponsive dermatophytosis is being increasingly encountered in our country. It runs a protracted course with exacerbations and remissions. However, there is little information regarding the extent of the problem and the characteristics of recurrent dermatophytosis in published literature.

Aims

We sought to determine the prevalence, risk factors and clinical patterns of recurrent dermatophytosis in our institution. We also investigated the causative dermatophyte species and antifungal susceptibility patterns in these species.

Methods

One hundred and fifty patients with recurrent dermatophytosis attending the outpatient department of the Postgraduate Institute of Medical Education and Research, Chandigarh, India were enrolled in the study conducted from January 2015 to December 2015. A detailed history was obtained in all patients, who were then subjected to a clinical examination and investigations including a wet preparation for direct microscopic examination, fungal culture and antifungal susceptibility tests.

Results

Recurrent dermatophytosis was seen in 9.3% of all patients with dermatophytosis in our study. Trichophyton mentagrophytes was the most common species identified (36 patients, 40%) samples followed by T. rubrum (29 patients, 32.2%). In-vitro antifungal susceptibility testing showed that the range of minimum inhibitory concentrations (MIC) on was lowest for itraconazole (0.015-1), followed by terbinafine (0.015-16), fluconazole (0.03-32) and griseofulvin (0.5-128) in increasing order.

Limitation

A limitation of this study was the absence of a suitable control group (eg. patients with first episode of typical tinea).

Conclusion

Recurrence of dermatophytosis was not explainable on the basis of a high (MIC) alone. Misuse of topical corticosteroids, a high number of familial contacts, poor compliance to treatment over periods of years, and various host factors, seem to have all contributed to this outbreak of dermatophytosis in India.

Therapy and Antifungal Susceptibility Profile of Microsporum canis

Microsporum canis is a worldwide diffused zoophilic dermatophyte which causes clinical conditions often characterised by multifocal alopecia, scaling, and circular lesions in many animal species, including humans. A large variety of oral and topical antifungal protocols is available for treating M. canis infection. However, the efficacy of these drugs and treatment protocols is variable, with treatment failure up to 40% of patients possibly due to resistance phenomena. The lack of standardised reference methods for evaluating the antifungal susceptibility of M. canis represents a major hindrance in assessing microbiological resistance in unresponsive clinical cases. Therefore, data about conventional therapy against M. canis and the protocols employed to test the antifungal activity of the most commonly employed drugs (i.e., azoles, polyenes, allylamines, and griseofulvin) have been summarised herein. This article focuses on technical parameters used for antifungal susceptibility tests, their effects on the minimum inhibitory concentration value, as well as their clinical implications.

Modeling dermatophytosis in reconstructed human epidermis: A new tool to study infection mechanisms and to test antifungal agents

Dermatophytosis is a superficial fungal infection of keratinized structures that exhibits an increasing prevalence in humans and is thus requesting novel prophylactic strategies and therapies. However, precise mechanisms used by dermatophytes to adhere at the surface of the human epidermis and invade its stratum corneum are still incompletely identified, as well as the responses provided by the underlying living keratinocytes during the infection. We hereby report development of an in vitro model of human dermatophytosis through infection of reconstructed human epidermis (RHE) by arthroconidia of the anthropophilic Trichophyton rubrum species or of the zoophilic Microsporum canis and Arthroderma benhamiae species. By modulating density of arthroconidia in the inoculum and duration of exposure to such pathogens, fungal infection limited to the stratum corneum was obtained, mimicking severe but typical in vivo situation. Fungal elements in infected RHE were monitored over time by histochemical analysis using periodic-acid Schiff-staining or quantified by qPCR-detection of fungal genes inside RHE lysates. This model brings improvements to available ones, dedicated to better understand how dermatophytes and epidermis interact, as well as to evaluate preventive and therapeutic agents. Indeed, miconazole topically added to RHE was demonstrated to inhibit fungal infection in this model.

Thigmo Responses: The Fungal Sense of Touch

The growth and development of most fungi take place on a two-dimensional surface or within a three-dimensional matrix. The fungal sense of touch is therefore critical for fungi in the interpretation of their environment and often signals the switch to a new developmental state. Contact sensing, or thigmo-based responses, include thigmo differentiation, such as the induction of invasion structures by plant pathogens in response to topography; thigmonasty, where contact with a motile prey rapidly triggers its capture; and thigmotropism, where the direction of hyphal growth is guided by physical features in the environment. Like plants and some bacteria, fungi grow as walled cells. Despite the well-demonstrated importance of thigmo responses in numerous stages of fungal growth and development, it is not known how fungal cells sense contact through the relatively rigid structure of the cell wall. However, while sensing mechanisms at the molecular level are not entirely understood, the downstream signaling pathways that are activated by contact sensing are being elucidated. In the majority of cases, the response to contact is complemented by chemical cues and both are required, either sequentially or simultaneously, to elicit normal developmental responses. The importance of a sense of touch in the lifestyles and development of diverse fungi is highlighted in this review, and the candidate molecular mechanisms that may be involved in fungal contact sensing are discussed.

The Role of NADPH Oxidase in the Inhibition of Trichophyton rubrum by 420-nm Intense Pulsed Light

Objectives: To evaluate the effect of intense pulsed light (IPL) on Trichophyton rubrum and investigate its mechanism of action.

Methods: The viability of fungi treated with IPL alone and with IPL combined with an NADPH oxidase inhibitor (DPI) pretreatment was determined by MTT assays. The reactive oxygen species (ROS) were quantified with a DCFH-DA fluorescent probe. Malondialdehyde (MDA) content and superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities were determined by commercial kits. The transcription of the Nox gene was quantified using quantitative real-time PCR (qRT-PCR) analysis, and micromorphology was observed using scanning electron microscopy (SEM). In addition, fungal keratinase activity was detected by measuring dye release from keratin azure.

Results: The growth declined with statistical significance after 6 h of treatment (P < 0.001). The ROS and MDA content increased after IPL treatment, whereas the SOD and GSH-Px activity decreased. Nox gene expression was upregulated, and the micromorphology was damaged. Keratinase activity decreased. Fungi that received DPI pretreatment exhibited contrasting outcomes.

Conclusion: We found that 420-nm IPL significantly inhibited the growth and pathogenicity of T. rubrum in vitro. A suggested mechanism involves Nox as a factor that mediates 420-nm IPL-induced oxidative damage of T. rubrum.

Changing in the Epidemiology of Tinea Capitis among School Children in Egypt

Background

Tinea capitis remains a prevalent health problem among school-aged children.

Objective

To estimate the prevalence of tinea capitis among primary school students, in Fayoum, Egypt with identification of etiological agents in both public and private primary schools.

Methods

A cross-sectional study was conducted in twelve primary schools. The students were selected from different grades with a total number of 12,128 students. Hair and scalp were clinically examined for any lesions that may suspect tinea capitis and mycological samples were collected for direct microscopy and culture.

Results

The prevalence of tinea capitis in the study group was 0.4% and higher in public than private schools (73.5% versus 26.5% respectively). Boys were more affected than girls with boy to girls' ratio 5:1. Intrafamily history of infection was present in 40.8% of tested group while 51% showed low social standard profile. Mycological culture revealed that Microsporum canis was the predominant isolated organism followed by M. audouinii (52% and 36% respectively).

Conclusion

M. canis is replacing Trichophyton violaceum as an etiology for tinea capitis in Egypt with lower prevalence rate than reported previously.

Are Th17 Cells Playing a Role in Immunity to Dermatophytosis?

Despite their superficial localization in the skin, pathogenic dermatophytes can induce a complex but still misunderstood immune response in their hosts. The cell-mediated immunity (CMI) is correlated with both clinical recovery and protection against reinfection, and CD4+ T lymphocytes have been recognized as a crucial component of the immune defense against dermatophytes. Before the discovery of the Th17 pathway, CMI was considered to be only dependent of Th1 cells, and thus most studies on the immunology of dermatophytosis have focused on the Th1 pathway. Nevertheless, the fine comparative analysis of available scientific data on immunology of dermatophytosis in one hand and on the Th17 pathway mechanisms involved in opportunistic mucosal fungal infections in the other hand reveals that some key elements of the Th17 pathway can be activated by dermatophytes. Stimulation of the Th17 pathway could occur through the activation of some C-type lectin-like receptors and inflammasome in antigen-presenting cells. The Th17 cells could go back to the affected skin and by the production of signature cytokines could induce the effector mechanisms like the recruitment of polymorphonuclear neutrophils and the synthesis of antimicrobial peptides. In conclusion, besides the Th1 pathway, which is important to the immune response against dermatophytes, there are also growing evidences for the involvement of the Th17 pathway.

The Changing Face of Dermatophytic Infections Worldwide

Dermatophytes evolve along with the geography and socioeconomic conditions. Epidermophyton floccosum, Microsporum audouinii and Trichophyton schoenleinii acted as the major pathogens of superficial fungal diseases 100 years ago, but their frequency decreased dramatically since the middle of the twentieth century and they are limited to some less-developed countries nowadays; meanwhile, frequency of Trichophyton rubrum, Trichophyton interdigitale, Trichophyton tonsurans and Microsporum canis increased gradually, and these fungi have become the major species globally. Some other dermatophytes, i.e., Trichophyton violaceum, Trichophyton verrucosum and Microsporum ferrugineum, are mainly endemic in some parts of Africa, Asia and Europe. At present, T. rubrum is the leading pathogen for skin and nail fungal infections, whereas M. canis, T. tonsurans and T. violaceum present as the predominant dermatophytes involved in tinea capitis. Population mobility, changes in human lifestyle and advents of antifungal drugs will continually drive the dermatophyte evolution in the skin microenvironment. Comprehensive observation is needed to better understand this kind of organisms and prospect the trends of their changes in future.

RNA Sequencing-Based Genome Reannotation of the Dermatophyte Arthroderma benhamiae and Characterization of Its Secretome and Whole Gene Expression Profile during Infection

Dermatophytoses (ringworm, jock itch, athlete’s foot, and nail infections) are the most common fungal infections, but their virulence mechanisms are poorly understood. Combining transcriptomic data obtained from growth under various culture conditions with data obtained during infection led to a significantly improved genome annotation. About 65% of the protein-encoding genes predicted with our protocol did not match the existing annotation for A. benhamiae. Comparing gene expression during infection on guinea pigs with keratin degradation in vitro, which is supposed to mimic the host environment, revealed the critical importance of using real in vivo conditions for investigating virulence mechanisms. The analysis of genes expressed in vivo, encoding cell surface and secreted proteins, particularly proteases, led to the identification of new allergen and virulence factor candidates.

Dermatophytes are the most common agents of superficial mycoses in humans and animals. The aim of the present investigation was to systematically identify the extracellular, possibly secreted, proteins that are putative virulence factors and antigenic molecules of dermatophytes. A complete gene expression profile of Arthroderma benhamiae was obtained during infection of its natural host (guinea pig) using RNA sequencing (RNA-seq) technology. This profile was completed with those of the fungus cultivated in vitro in two media containing either keratin or soy meal protein as the sole source of nitrogen and in Sabouraud medium. More than 60% of transcripts deduced from RNA-seq data differ from those previously deposited for A. benhamiae. Using these RNA-seq data along with an automatic gene annotation procedure, followed by manual curation, we produced a new annotation of the A. benhamiae genome. This annotation comprised 7,405 coding sequences (CDSs), among which only 2,662 were identical to the currently available annotation, 383 were newly identified, and 15 secreted proteins were manually corrected. The expression profile of genes encoding proteins with a signal peptide in infected guinea pigs was found to be very different from that during in vitro growth when using keratin as the substrate. Especially, the sets of the 12 most highly expressed genes encoding proteases with a signal sequence had only the putative vacuolar aspartic protease gene PEP2 in common, during infection and in keratin medium. The most upregulated gene encoding a secreted protease during infection was that encoding subtilisin SUB6, which is a known major allergen in the related dermatophyte Trichophyton rubrum.

IMPORTANCE Dermatophytoses (ringworm, jock itch, athlete’s foot, and nail infections) are the most common fungal infections, but their virulence mechanisms are poorly understood. Combining transcriptomic data obtained from growth under various culture conditions with data obtained during infection led to a significantly improved genome annotation. About 65% of the protein-encoding genes predicted with our protocol did not match the existing annotation for A. benhamiae. Comparing gene expression during infection on guinea pigs with keratin degradation in vitro, which is supposed to mimic the host environment, revealed the critical importance of using real in vivo conditions for investigating virulence mechanisms. The analysis of genes expressed in vivo, encoding cell surface and secreted proteins, particularly proteases, led to the identification of new allergen and virulence factor candidates.

Antifungal Potential and Antioxidant Efficacy in the Shell Extract of Cocos nucifera (L.) (Arecaceae) against Pathogenic Dermal Mycosis

Background: Coconut is a tropical fruit well known for its essential oils that have been recognized for their biological activities since ancient times. There have been no previous investigations on the essential oils from coconut shells. Method: The shell extract of Cocos nucifera (L.) was prepared by the Soxhlet method and total phenolic content (TPC) in the extract was determined by Folin-Ciocalteu (FC) assay. The antioxidant potential of the coconut shell extract was evaluated by using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay. Minimum inhibitory concentration (MIC) of the extract was determined by the strip method against clinically isolated dermal mycosis of 20 infected patients. Result: Total antioxidant activity varied from 92.32% to 94.20% and total phenolic content was found at 5.33 ± 0.02 mg/g in the coconut shell extract. The extract was found to be most effective as an antifungal against human pathogenic fungi, including A. niger, A. flavus, T. rubrum, M. canis, M. gypseum, A. fumigates, T. mentagrophyte and T. vercossum. The crude shell extract was highly effective against all dermal mycosis tested with the MIC ranging from 62 mm to 90 mm, whereas all fungal samples showed good inhibitory effect. Conclusion: The results of the present study provide a potential cure for microbial infections.

Genotyping and In Vitro Antifungal Susceptibility Testing of Fusarium Isolates from Onychomycosis in India

Onychomycosis refers to fungal infection of the nail and is commonly caused by dermatophytes, while yeasts and non-dermatophytic molds (NDM) are increasingly recognized as pathogens in nail infections. The present study was done to delineate molecular epidemiology of Fusarium onychomycosis in India. Five hundred nail samples of Indian patients clinically suspected of onychomycosis were subjected to direct microscopy and fungal culture. Representative Fusarium isolates were further identified to species level by multi-locus sequencing for internal transcribed spacer, translation elongation factor 1 alpha (tef1-α) and RNA polymerase II subunit (rpb2) regions (primer pairs: ITS1/ITS4, EF1/EF2, 5f2/7cr, respectively). These representative strains were also tested for in vitro antifungal susceptibility by the broth microdilution method. Members of the genus Fusarium proved to be the most common NDM responsible for onychomycosis. The Fusarium spp. responsible for onychomycosis belonged to the Fusarium solani species complex (F. keratoplasticum and F. falciforme) and Fusarium fujikuroi species complex (F. proliferatum, F. acutatum and F. sacchari). Antifungal susceptibility results indicated that amphotericin B was the most effective antifungal across all isolates (MIC ranging 0.5-2 mg/L), followed by voriconazole (MIC ranging 1-8 µg/ml). However, a large variation was shown in susceptibility to posaconazole (MIC ranging 0.5 to >16 µg/ml). To conclude, we identified different Fusarium spp. responsible for onychomycosis in India with variation within species in susceptibility to antifungal agents, showing that fusariosis requires correct and prompt diagnosis as well as antifungal susceptibility testing.

Overexpression of TLR-2 and TLR-4 mRNA in feline polymorphonuclear neutrophils exposed to Microsporum canis

BACKGROUND

Polymorphonuclear neutrophils (PMNs), along with macrophages, are the first leukocytes recruited to the site of infection in dermatophytoses and are responsible for the in fine elimination of the fungus. It has been demonstrated that feline PMNs produce pro-inflammatory cytokines after stimulation with Microsporum canis. The activation of these cells results from the recognition of specific PAMPs (pathogen associated molecular patterns) from M. canis by PRRs (pattern recognition receptors) of PMNs. The C-type lectin receptors (CLRs) and toll-like receptors (TLRs) are the two main PRRs in phagocytic cells that recognize fungal components.

HYPOTHESIS/OBJECTIVE

The aim of this study was to evaluate the expression of TLR-2, TLR-4 and dectin-1 mRNA in feline PMNs exposed to different components from M. canis.

METHODS

Feline PMNs were stimulated for 2 h or 4 h with either live arthroconidia, heat-killed arthroconidia or secreted components from M. canis. The levels of TLR-2, TLR-4 and dectin-1 mRNA were assessed by RT-qPCR.

RESULTS

Results showed an increase of TLR-2 and TLR-4 mRNA levels in feline PMNs stimulated with live and heat-killed arthroconidia, but not in those stimulated with the secreted components from M. canis. No significant variation in dectin-1 mRNA expression was observed in PMNs stimulated with the different fungal components.

CONCLUSIONS AND CLINICAL IMPORTANCE

The overexpression of TLR-2 and TLR-4 mRNAs in stimulated feline PMNs suggests that these receptors are involved in the host immune response through the recognition of M. canis PAMPs.

Two Feet-One Hand Syndrome: A Case Report / Sindrom dva stopala i jedne šake – prikaz slučaja

Two feet-one hand syndrome is a superficial fungal infections of the skin which involves both feet and one hand. Trichophyton rubrum and occasionally Trichophyton mentagrophytes are the usual causative organisms.

We present a 32-year-old healthy man with sharply demarcated papular erythematous and squamous lesions on dorsal aspect of the feet and diffuse dry scaling lesions of the right palm. In this syndrome, the development of tinea pedis generally precedes the development of tinea manus, which usually occurs on the hand that excoriated the pruritic feet or picked the toenails with onychomycosis. Our patient often used his dominant right hand to scratch the feet.

On mycological examination, fungal spores and mycelia were present and Trichophyton mentagrophytes was isolated. The patient was treated with itraconazole 200 mg daily for two weeks and topical terbinafine cream for four weeks. After the treatment all lesions resolved and fungal culture was negative.

Early diagnoses and treatment of tinea pedis and education about prophylaxis, constant care and regular medical assistance would minimize this problem in predisposed individuals.

Dermatophytes and other associated fungi in patients attending to some hospitals in Egypt

Dermatophytes are keratinophilic fungi that infect keratinized tissues causing diseases known as dermatophytoses. Dermatophytes are classified in three genera, Epidermophyton, Microsporum, and Trichophyton. This investigation was performed to study the prevalence of dermatomycosis among 640 patients being evaluated at the dermatology clinics at Kasr elainy, El-Husein and Said Galal hospitals in Cairo and Giza between January 2005 and December 2006. The patients were checked for various diseases. Tinea capitis was the most common clinical disease followed by tinea pedis and tinea corporis. Tinea cruris and tinea unguium were the least in occurrence. Tinea versicolor also was detected. The most susceptible persons were children below 10 years followed by those aged 31-40 years. Unicellular yeast was the most common etiological agent and T. tonsuranswas the second most frequent causative agent followed by M. canis.

Low DEFB4 copy number and high systemic hBD-2 and IL-22 levels are associated with dermatophytosis

Dermatophytes initiate dermatophytosis, but susceptibility to infection is dictated by host genetic factors, although the role of some of these-such as human beta-defensin 2 (hBD-2) genomic (DEFB4) copy number (CN) variation and its induction by IL-22-remains unclear. This was investigated in this cross-sectional study in 442 unrelated Caucasian subjects, including 195 healthy controls and 247 dermatophytosis patients who were divided into five subgroups according to clinical presentation. DNA samples were evaluated for DEFB4 CN variation by relative quantification using the comparative CT method, and serum hBD-2 and IL-22 levels were determined by ELISA. DEFB4 CN in patients was significantly lower and, except in the tinea cruris subgroup, serum hBD-2 levels were higher than in controls. The positive correlation between hBD-2 levels and DEFB4 CN observed in controls was not detected in patients, who also had higher serum IL-22 levels that were positively correlated with hBD-2 levels. Moreover, unlike in control subjects, the serum IL-22 level was negatively correlated with DEFB4 CN in patients. Taken together, these findings suggest an association between decreased DEFB4 CN, elevated serum hBD-2 and IL-22 levels, and dermatophytosis, underscoring a gene/cytokine interaction in the occurrence of this infection.

Dermatomycoses and inflammation: The adaptive balance between growth, damage, and survival

Dermatomycosis is characterized by both superficial and subcutaneous infections of keratinous tissues and mucous membranes caused by a variety of fungal agents, the two most common classes being dermatophytes and yeasts. Overall, the stepwise process of host infection is similar among the main dermatomycotic species; however, the species-specific ability to elicit a host reaction upon infection is distinct. Yeasts such as Candida albicans elicit a relatively low level of host tissue damage and inflammation during pathogenic infection, while dermatophytes may induce a higher level of tissue damage and inflammatory reaction. Both pathogens can, however, manipulate the host's immune response, ensuring survival and prolonging chronic infection. One common element of most dermatomycotic infections is the disease burden caused by inflammation and associated signs and symptoms, such as erythema, burning and pruritus. There is a strong clinical rationale for the addition of a topical corticosteroid agent to an effective antimycotic therapy, especially in patients who present with inflammatory dermatomycoses (e.g., tinea inguinalis). In this review, we aim to compare the pathogenesis of common dermatomycotic species, including Candida yeasts (Candida albicans), dermatophytes (Trichophyton, Epidermophyton or Microsporum species), and other pathogenic yeasts (Malassezia), with a special focus on unique species-specific aspects of the respective infection processes, the interaction between essential aspects of pathogenic infection, the different roles of the host inflammatory response, and the clinical consequences of the infection-related tissue damage and inflammation. We hope that a broader understanding of the various mechanisms of dermatomycoses may contribute to more effective management of affected patients.