Global Insights and Trends in Research on Dermatophytes and Dermatophytosis: A Bibliometric Analysis.

BACKGROUND: Dermatophytosis, caused by dermatophytes, affects up to 25% of people globally, with higher rates observed in Africa and Asia. While these infections are usually superficial, they can become severe in immunocompromised individuals. Despite their high prevalence, scientific research on dermatophytes is limited and the epidemiological data available are insufficient. In addition, diagnostic methods are not standardised and there are challenges with resistance to antifungals. OBJECTIVES: This study aimed to conduct a bibliometric analysis of scientific publications related to dermatophytes and dermatophytosis to assess research output and trends. METHODS: A bibliometric analysis of publications from 2000 to 2023 in Web of Science and Scopus examined trends, citation counts, publication types, key journals, top authors and institutions and funding sources. RESULTS: The analysis revealed a significant increase in dermatophyte-related publications, with 15,868 articles retrieved from the Web of Science and 23,189 from Scopus. Research articles dominated the output, constituting 76.2% in Web of Science and 80% in Scopus. Peak publication years were 2019, 2021 and 2022 in Web of Science, and 2020, 2021 and 2023 in Scopus, with lower output between 2000 and 2002. The United States and India were the leading contributors, followed by Brazil and China, though citation metrics varied. Although there has been a rise in the number of publications, the amount of research conducted on dermatophytes is still very limited in comparison with other types of fungal diseases. CONCLUSIONS: Dermatophyte-related research has increased over the past 2 decades. However, research gaps remain, particularly compared with other fungal diseases. Advances in diagnostics, antifungal testing and taxonomic classification are urgently needed. The study underscores the need for continued research and global collaboration to address these issues.

Design, synthesis, docking studies and bioactivity evaluation of 1,2,3-triazole eugenol derivatives.

Aim: The design, synthesis, docking studies and evaluation of the in vitro antifungal and cytotoxic properties of eugenol (EUG) containing 1,2,3-triazole derivatives are reported. Most of the derivatives have not been reported.Materials & methods: The EUG derivatives were synthesized, molecular docked and tested for their antifungal activity.Results: The compounds showed potent antifungal activity against Trichophyton rubrum, associated with dermatophytosis. Compounds 2a and 2i exhibited promising results, with 2a being four-times more potent than EUG. The binding mode prediction was similar to itraconazole in the lanosterol-14-α-demethylase wild-type and G73E mutant binding sites. Additionally, the pharmacokinetic profile prediction suggests good gastrointestinal absorption and potential oral administration.Conclusion: Compound 2a is a promising antifungal agent against dermatophytosis caused by T. rubrum.

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Antifungal Activity of Aniba canelilla (Kunth) Mez Essential Oil and Its Main Compound 1-Nitro-2-Phenylethane against Dermatophytes.

The essential oil of Aniba canelilla (Kunth) Mez (EOAC), an Amazon plant composed of a rare nitro compound, has shown scientific evidence of antifungal activity but is still unexplored against dermatophytes. The antifungal susceptibility of EOAC and its main compound, 1-nitro-2-phenylethane (NP), was evaluated against dermatophytes (Trichophyton rubrum, T. mentagrophytes and Microsporum canis), evidencing antifungal activity with an inhibitory concentration lower than 256 µg/mL. The mechanism of action was also evaluated, and it is suggested that EOAC and NP have fungicidal action in the fungal membrane, since the antifungal activity occurs through a modification of the shape of the conidial structures of the fungus, showing the permeability of the intracellular content due to the visually observed plasmolysis and cytosolic extravasation through an osmotic process. These results suggest the essential oil and its main compound are promising plant-derived alternatives for treating ungual dermatophytosis.

Synergistic activity between conventional antifungals and chalcone-derived compound against dermatophyte fungi and Candida spp.

The scarce antifungal arsenal, changes in the susceptibility profile of fungal agents, and lack of adherence to treatment have contributed to the increase of cases of dermatomycoses. In this context, new antimicrobial substances have gained importance. Chalcones are precursors of the flavonoid family that have multiple biological activities, have high tolerability by humans, and easy synthesis. In this study, we evaluated the in vitro antifungal activity, alone and in combination with conventional antifungal drugs, of the VS02-4'ethyl chalcone-derived compound against dermatophytes and Candida spp. Susceptibility testing was carried out by broth microdilution. Experiments for determination of the target of the compound on the fungal cell, time-kill kinetics, and toxicity tests in Galleria mellonella model were also performed. Combinatory effects were evaluated by the checkerboard method. Results showed high activity of the compound VS02-4'ethyl against dermatophytes (MIC of 7.81-31.25 µg/ml). The compound targeted the cell membrane, and the time-kill test showed the compound continues to exert gradual activity after 5 days on dermatophytes, but no significant activity on Candida. Low toxicity was observed at 250 mg/kg. Excellent results were observed in the combinatory test, where VS02-4'ethyl showed synergistic interactions with itraconazole, fluconazole, terbinafine, and griseofulvin, against all isolates tested. Although further investigation is needed, these results revealed the great potential of chalcone-derived compounds against fungal infections for which treatments are long and laborious.

Exploring the Complexity of the Interaction between T. rubrum and S. aureus/S. epidermidis in the Formation of Polymicrobial Biofilms.

Dermatophytes associated with bacteria can lead to severe, difficult-to-treat infections and contribute to chronic infections. Trichophyton rubrum, Staphylococcus aureus, and Staphylococcus epidermidis can form biofilms influenced by nutrient availability. This study investigated biofilm formation by these species by utilizing diverse culture media and different time points. These biofilms were studied through scanning electron microscopy (SEM), confocal laser scanning microscopy (CLSM), biomass, metabolic activity, and colony-forming units (CFUs). The results revealed that mixed biofilms exhibited high biomass and metabolic activity when cultivated in the brain heart infusion (BHI) medium. Both bacterial species formed mature biofilms with T. rubrum within 72 h, irrespective of media. The timing of bacterial inoculation was pivotal in influencing biomass and metabolic activity. T. rubrum's development within mixed biofilms depended on bacterial addition timing, while pre-adhesion influenced fungal growth. Bacterial communities prevailed initially, while fungi dominated later in the mixed biofilms. CLSM revealed 363 µm thick T. rubrum biofilms with septate, well-developed hyphae; S. aureus (177 µm) and S. epidermidis (178 µm) biofilms showed primarily cocci. Mixed biofilms matched T. rubrum's thickness when associated with S. epidermidis (369 µm), with few hyphae initially. Understanding T. rubrum and Staphylococcal interactions in biofilms advances antimicrobial resistance and disease progression knowledge.

Molecular Verification of Trichophyton in the Brazilian URM Culture Collection.

Trichophyton species cause dermatophytosis in humans, with a high, worldwide frequency of reports and important public health relevance. We evaluated 61 Trichophyton strains from different sources deposited in the University Recife Mycology (URM) culture collection of the Universidade Federal de Pernambuco, Brazil. Strains were phenotypically identified and confirmed by sequencing Internal Transcribed Spacers rDNA and partial beta-tubulin 2-exon. Additionally, we evaluated their susceptibility to terbinafine and itraconazole. Physiological analyses included urease activity and growth in casein medium. Phenotypic methods allowed the reliable identification of T. rubrum only, whereas, for other species, molecular methods were mandatory. All Trichophyton species exhibited susceptibility profiles to itraconazole (0.04-5.33 µg/mL) and terbinafine (0.17-3.33 µg/mL). Our analyses revealed a heterogeneous distribution of T. mentagrophytes, which does not support the current distribution within the species complex of T. mentagrophytes and its genotypes.

Tinea corporis intrafamilial infection in pets due to Microsporum canis

ABSTRACT Microsporum canis, one of the most widespread dermatophytes worldwide, is a zoonotic microorganism that transmits infection from reservoirs such as cats and dogs to humans. This microorganism is associated with Tinea corporis and other clinical manifestations; however, few studies have used genetic surveillance to determine and characterize the process of zoonotic transmission. In this study, we show a clear example of zoonotic transmission from a cat to an intrafamilial environment, where it caused Tinea corporis by infection with M. canis. Molecular characterization using the b-tubulin gene and Random Amplified Polymorphic DNA analysis made it possible to determine that the six isolates of M. canis obtained in this study belonged to the same genetic variant or clone responsible for reservoir-reservoir or reservoir-human transmission.

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

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

Membranolytic Activity Profile of Nonyl 3,4-Dihydroxybenzoate: A New Anti-Biofilm Compound for the Treatment of Dermatophytosis.

The ability of dermatophytes to live in communities and resist antifungal drugs may explain treatment recurrence, especially in onychomycosis. Therefore, new molecules with reduced toxicity that target dermatophyte biofilms should be investigated. This study evaluated nonyl 3,4-dihydroxybenzoate (nonyl) susceptibility and mechanism of action on planktonic cells and biofilms of T. rubrum and T. mentagrophytes. Metabolic activities, ergosterol, and reactive oxygen species (ROS) were quantified, and the expression of genes encoding ergosterol was determined by real-time PCR. The effects on the biofilm structure were visualized using confocal electron microscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). T. rubrum and T. mentagrophytes biofilms were susceptible to nonyl and resistant to fluconazole, griseofulvin (all strains), and terbinafine (two strains). The SEM results revealed that nonyl groups seriously damaged the biofilms, whereas synthetic drugs caused little or no damage and, in some cases, stimulated the development of resistance structures. Confocal microscopy showed a drastic reduction in biofilm thickness, and transmission electron microscopy results indicated that the compound promoted the derangement and formation of pores in the plasma membrane. Biochemical and molecular assays indicated that fungal membrane ergosterol is a nonyl target. These findings show that nonyl 3,4-dihydroxybenzoate is a promising antifungal compound.

Phenotypic and Genotypic Identification of Dermatophytes from Mexico and Central American Countries.

Dermatophytes are fungi included in the genera Trichophyton, Microsporum, Epidermophyton, Nannizzia, Paraphyton, Lophophyton, and Arthroderma. Molecular techniques have contributed to faster and more precise identification, allowing significant advances in phylogenetic studies. This work aimed to identify clinical isolates of dermatophytes through phenotypic (macro- and micromorphology and conidia size) and genotypic methods (sequences of ITS regions, genes of ß tubulin (BT2), and elongation factor α (Tef-1α)) and determine the phylogenetic relationships between isolates. Ninety-four dermatophyte isolates from Costa Rica, Guatemala, Honduras, Mexico, and the Dominican Republic were studied. The isolates presented macro- and micromorphology and conidia size described for the genera Trichophyton, Microsporum, and Epidermophyton. Genotypic analysis classified the isolates into the genera Trichophyton (63.8%), Nannizzia (25.5%), Arthroderma (9.6%), and Epidermophyton (1.1%). The most frequent species were T. rubrum (26 isolates, 27.6%), T. interdigitale (26 isolates, 27.6%), and N. incurvata (11 isolates, 11.7%), N. gypsea and A. otae (nine isolates, 9.6%), among others. The genotypic methods clarified the taxonomic status of closely related species. For instance, the ITS and BT2 markers of T. rubrum/T. violaceum did not differ but the Tef-1α gene did. On the other hand, the three markers differed in T. equinum/T. tonsurans. Therefore, the ITS, BT2, and Tef-1α genes are useful for typing in phylogenetic analyses of dermatophytes, with Tef-1α being the most informative locus. It should be noted that isolate MM-474 was identified as T. tonsurans when using ITS and Tef-1α, but when using BT2, it was identified as T. rubrum. On the other hand, no significant difference was found when comparing the methods for constructing phylogenies, as the topologies were similar.

Bovine ringworm - Detection of Trichophyton verrucosum by SYBR-Green real-time PCR.

Trichophyton verrucosum is the most commonly dermatophyte involved in cattle ringworm. This work reported a case of bovine dermatophytosis due to Trichophyton verrucosum detected from the clinical sample by SYBR-Green real-time PCR. The strategy was based on the DNA extraction directly from the infected hair followed by real-time PCR and melting-point analysis. A faster and differential diagnosis was observed when compared to the conventional mycological methodology for detection and identification of Trichophyton verrucosum.

Determinación de la concentración mínima inhibitoria de lotes de OLEOZON® tópico frente a Trichophyton rubrum, Trichophyton mentagrophytes y Epidermophyton floccosum / Determination of the minimum inhibitory concentration of batches of topical OLEOZON® against trichophyton rubrum, trichophyton mentagrophytes and epidermophyton floccosum

Introducción: En la actualidad las infecciones por hongos afectan entre el 20 y el 25 por ciento de la población. Objetivo: Determinar la concentración mínima inhibitoria de dos lotes de OLEOZON® almacenados a temperaturas de 5 y 30°C en envases de vidrio y polietileno de alta densidad, durante 24 meses como parte del estudio de estabilidad del OLEOZON® tópico. Métodos: Mediante el método dilución en agar fueron evaluadas cinco concentraciones del producto frente a los dermatofitos trichophyton rubrum, trichophyton mentagrophytes y epidermophyton floccosum. Resultados: Se obtuvo que el 8,9 mg/mL fue el valor de la CMI para las cepas evaluadas en el estudio vida de estante; se observó en el estudio acelerado el mismo valor frente a las cepas de trichophyton mientras que para epidermophyton floccosum fue de 17,8 mg/mL a excepción del envase frasco de vidrio del lote 803295 donde se obtuvo 8,9 mg/mL. El análisis estadístico, tanto del estudio acelerado como en vida de estante, mostró que existe diferencia estadísticamente significativa entre el primer y el último mes de ensayo, estas son las diferencias más apreciables en los lotes almacenados en frasco de vidrio. El OLEOZON® tópico almacenado en frasco de polietileno de alta densidad presentó mejores valores de actividad frente a los dermatofitos. Conclusiones: Todos los valores de la concentración mínima inhibitoria encontrados, independiente del tipo de envase, el tiempo o la temperatura de almacenamiento, muestran que el producto mantiene su actividad antifúngica. Se evidenció una similitud entre las cepas del género trichophyton en comparación con el género epidermophyton(AU)

Introduction: Currently fungal infections affect between 20 and 25percent of the population. Objective: To determine the minimum inhibitory concentration of two batches of OLEOZON® stored at temperatures of 5 and 30 0C in glass and high-density polyethylene containers, for 24 months as part of the stability study of topical OLEOZON®. Methods: Using the agar dilution method, five concentrations of the product were evaluated against the dermatophytes Trichophyton rubrum, Trichophyton mentagrophytes and Epidermophyton floccosum. Results: It was found that 8.9 mg/mL was the MIC value for the strains evaluated in this shelf life study; and the same value was observed in the accelerated study against the trichophyton strains, while for epidermophyton floccosum it was 17.8 mg/mL with the exception of the glass bottle container of batch 803295 where 8.9 mg/mL was obtained. The statistical analysis, both in the accelerated study and in shelf life, showed that there is a statistically significant difference between the first and the last month of the trial, these are the most appreciable differences in the batches stored in glass jars. Topical OLEOZON® stored in a high-density polyethylene bottle presented better activity values against dermatophytes. Conclusions: All the values of the minimum inhibitory concentration found, regardless of the type of container, the time or the storage temperature, show that the product maintains its antifungal activity during the months of study. A similarity was apparent between the strains of the genus trichophyton compared to the genus epidermophyton(AU)

Antifungal and Antibiofilm Activity of Riparin III against Dermatophytes.

The ability of dermatophytes to develop biofilms is possibly involved in therapeutic failure because biofilms impair drug effectiveness in the infected tissues. Research to find new drugs with antibiofilm activity against dermatophytes is crucial. In this way, riparins, a class of alkaloids that contain an amide group, are promising antifungal compounds. In this study, we evaluated the antifungal and antibiofilm activity of riparin III (RIP3) against Trichophyton rubrum, Microsporum canis, and Nannizzia gypsea strains. We used ciclopirox (CPX) as a positive control. The effects of RIP3 on fungal growth were evaluated by the microdilution technique. The quantification of the biofilm biomass in vitro was assessed by crystal violet, and the biofilm viability was assessed by quantifying the CFU number. The ex vivo model was performed on human nail fragments, which were evaluated by visualization under light microscopy and by quantifying the CFU number (viability). Finally, we evaluated whether RIP3 inhibits sulfite production in T. rubrum. RIP3 inhibited the growth of T. rubrum and M. canis from 128 mg/L and N. gypsea from 256 mg/L. The results showed that RIP3 is a fungicide. Regarding antibiofilm activity, RIP3 inhibited biofilm formation and viability in vitro and ex vivo. Moreover, RIP3 inhibited the secretion of sulfite significantly and was more potent than CPX. In conclusion, the results indicate that RIP3 is a promising antifungal agent against biofilms of dermatophytes and might inhibit sulfite secretion, one relevant virulence factor.

Dermatophytosis caused by Nannizzia nana (Microsporum nanum): a comprehensive review on a novel pathogen.

Keratinophilic fungi are mostly soil-inhabiting organisms with occasional infections in humans and animals. Even though most dermatophytes are host-adapted, cross-species infections are common by zoophilic and geophilic dermatophytes. N. nana is considered an etiological agent of ringworm in pigs but has also been isolated from other animals, including humans. However, it also possesses many characteristics of geophilic dermatophytes including the ability to grow in soil. N. nana produces characteristic pear-shaped macroconidia and usually exhibits an ectothrix pattern of hair infection. It has been isolated from dermatitis lesions as well as from soil. N. nana infections in pigs are not of much concern as far as economy or health is concerned. But it has been associated with onychomycosis and gonathritis in humans, which are significant in human medicine. The shift in the predominance of dermatophytes in humans and the ability to evolve into a potential tinea pathogen necessitates more understanding of the physiology and genetics of N. nana. In this review, we have attempted a detailed analysis of the studies about N. nana, emphasizing growth and cultural characters, physiology, isolation, infection in humans and animals, molecular characterization and antifungal susceptibility.

The Transcription Factor StuA Regulates the Glyoxylate Cycle in the Dermatophyte Trichophyton rubrum under Carbon Starvation.

Trichophyton rubrum is the primary causative agent of dermatophytosis worldwide. This fungus colonizes keratinized tissues and uses keratin as a nutritional source during infection. In T. rubrum-host interactions, sensing a hostile environment triggers the adaptation of its metabolic machinery to ensure its survival. The glyoxylate cycle has emerged as an alternative metabolic pathway when glucose availability is limited; this enables the conversion of simple carbon compounds into glucose via gluconeogenesis. In this study, we investigated the impact of stuA deletion on the response of glyoxylate cycle enzymes during fungal growth under varying culture conditions in conjunction with post-transcriptional regulation through alternative splicing of the genes encoding these enzymes. We revealed that the ΔstuA mutant downregulated the malate synthase and isocitrate lyase genes in a keratin-containing medium or when co-cultured with human keratinocytes. Alternative splicing of an isocitrate lyase gene yielded a new isoform. Enzymatic activity assays showed specific instances where isocitrate lyase and malate synthase activities were affected in the mutant strain compared to the wild type strain. Taken together, our results indicate a relevant balance in transcriptional regulation that has distinct effects on the enzymatic activities of malate synthase and isocitrate lyase.

ITS-RFLP optimization for dermatophyte identification from clinical sources in Alagoas (Brazil) versus phenotypic methods.

INTRODUCTION: Dermatophytoses are superficial mycoses, and the identification of their etiological agents is routinely performed by culture and microscopic features, which is time-consuming and relies on personnel expertise. Molecular approaches have been developed to provide faster and reliable results; therefore, this study aimed to identify dermatophytes isolated from Alagoas state patients, employing phenotypical and molecular methods. METHODOLOGY: Clinical samples for morphological identification were collected from private and public laboratories and cultivated on Sabouraud dextrose agar. DNA extraction was followed by ITS amplicon analysis after restriction enzyme digestion DdeI (ITS-RFLP). RESULTS: Out of fourteen representative strains, ITS-RFLP with DdeI efficiently identified Microsporum canis, Nannizzia gypsea, and Trichophyton rubrum, while species of the complex T. tonsurans/T. mentagrophytes presented the same restriction pattern. After genotyping, 2 T. tonsurans and 1 Microsporum sp. strain were reclassified as T. rubrum. CONCLUSIONS: RFLP of ITS-region followed by DdeI digestion produced faster and relatively reliable results than classic methods; however, this method has not been as efficient for closely related dermatophytes cryptic species.

Exposure to itraconazole influences the susceptibility to antifungals, physiology, and virulence of Trichophyton interdigitale.

Dermatophytosis is the most common human skin infection worldwide caused by dermatophytes, such as Trichophyton interdigitale and Trichophyton rubrum. Itraconazole (ITZ) is one of the main antifungals used to treat these infections. However, especially for onychomycosis, the treatment requires long-term regimens, increasing the possibility of drug resistance. We evaluated the effects of ITZ in the physiology, virulence, and interaction of T. interdigitale with phagocytes and mice cutaneous infection. In a screening test, fungal growth in the presence of ITZ led to the spontaneous selection of less susceptible T. interdigitale and T. rubrum strains. Interestingly, this phenotype was permanent for some T. interdigitale strains. Then, we studied three T. interdigitale strains: one susceptible and two ITZ-adapted. The ITZ-adapted strains were also less susceptible to the cell wall and membrane stressors, suggesting a multidrug resistance (MDR) phenotype associated with the increased ERG11 and MDR3 expression. These strains also presented substantial alterations in ergosterol content, lipid peroxidation, biofilm, and extracellular matrix production. During interaction with macrophages, ITZ-adapted strains were less engulfed but increased the intracellular oxidative and nitrosative bursts. In addition, ITZ-adapted strains presented a reduced ability to grow in a murine model of dermatophytosis, although causing the same tissue damage as the parental strain. In conclusion, the T. interdigitale ITZ adaptation increases tolerance to antifungals and alters the interaction with macrophages and a mammalian host. We hypothesized that successive exposure to ITZ may influence the emergence of adapted strains and lead to the recalcitrance of dermatophytosis.

Changes in antiparasitical activity of gold nanorods according to the chosen synthesis.

Gold nanorods (GNRs) are increasingly being studied for diagnostic and therapeutic purposes. Green synthesis based methods with natural compounds as additives stand out as a hope in terms of better synthesis methodology, with advantages of producing potentially less toxic and, perhaps, biologically active GNRs due to influence of natural additives used during synthesis. Exploring green chemistry using different natural phenolic compounds, the present work reveals different in vitro activity of GNRs evaluated against different parasites that causes skin infectious diseases compared to GNRs produced by convencional seed mediated method. This approach brings advantages in producing active GNRs, with ease calling, less cytotoxic and with a better selectivity index (SI) than GNRs synthesized by conventional seed mediated synthesis, opening new possibilities for therapies. Natural compounds used in green syntheses were gallic acid (GA), resveratrol (RSV) and a purified fraction of the hydroalcoholic extract of Stryphnodendron obovatum. GNRs exhibited great activity against Leishmania braziliensis, and the dermatophytes Tricophyton rubrum, T. interdigitale and Microsporum gypseum. The anti-Leishmania and antidermatophytic activity of GNRs reinforce the applicability of GNRs in biomedical field and the influence of synthesis method in biological activity, showing benefits related to the seedless synthesis with natural compounds. In addition, these preliminary results indicate the possibility of exploring at maximum the physical and chemical properties of GNRs in addition to the biological activity itself, such as the development of topical antiparasitic formulations for association with phototherapy.

Nail Clipping with PAS Stain and Correlation with Fungi Isolated in Culture: A Valuable Exchange in the Diagnosis of Onychomycosis.

Introduction: The etiological agents of onychomycosis are dermatophyte fungi, nondermatophyte filamentous fungi (NDFF), and yeasts. Nail clippings are an accurate tool for diagnosing onychomycosis. The objective of this study was to correlate the characteristics of fungi observed in nail clipping examinations with the results for agents isolated in culture, indicating whether the fungus found on microscopy is a dermatophyte, NDFF, or yeast. Methods: An observational descriptive study of onychomycosis nail clippings stained with PAS comparing culture results with microscopic criteria of fungi morphology, arrangement/orientation, and location of organisms in the nail and presence of neutrophils, serous lakes, and bacterial colonies was conducted. Results: Thirty-three nail clippings from 29 participants were analyzed. A statistically significant correlation (p < 0.05) was found between smooth/thin/long hyphae with a "combed" pattern and dermatophyte agents (sensitivity 89.4%, specificity 91.5%), and between irregular/thick/short anarchic distributed hyphae and nondermatophytes (sensitivity 61.5%, specificity 89.4%). No statistical association with region where fungi were in the nail or with the presence of neutrophils, serous lakes or bacteria was found. Small, rounded, yeast-like organisms correlated with Candida infection. Conclusions: Although not a substitute for culture, microscopic analysis of fungal structures offers good accuracy for differentiating agents of onychomycosis.

Trichophyton benhamiae, un dermatofito zoofílico emergente en Argentina con reservorio en cobayos: descripción de 7 casos en un hospital de la Ciudad Autónoma de Buenos Aires / Trichophyton benhamiae, an emergent zoonotic pathogen in Argentina associated with Guinea pigs: Description of 7 cases in Buenos Aires

Resumen Trichophyton benhamiae es un dermatofito zoofílico. Puede causar tinea corporis, tinea faciei y tinea capitis. Se caracteriza por producir lesiones inflamatorias, sobre todo en niños. El objetivo de esta publicación es describir 7 casos clínicos de pacientes pediátricos atendidos entre julio del 2019 y enero del 2020 en nuestra institución. A los pacientes se les solicitó estudio micológico convencional, con posterior confirmación con MALDI-TOF MS y secuencia-ción del ADN ribosomal. Se aisló e identificó T. benhamiae como agente etiológico; el nexo epidemiológico fue el contacto con cobayos. Estas son las primeras descripciones de infecciones causadas por T. benhamiae en Argentina. Al realizar estudios micológicos convencionales, este agente puede confundirse con otros dermatofitos, por lo tanto, se requieren herramientas como MALDI-TOF MS o la secuenciación para llegar a un diagnóstico definitivo. Es importante contar con datos epidemiológicos, como el contacto con mascotas no tradicionales, para una presunción diagnóstica adecuada.

Trichophyton benhamiae is a zoonotic dermatophyte that can cause tinea corporis, tinea faciei and tinea capitis, producing inflammatory lesions, especially in children. In this publication, we describe 7clinical cases of pediatric patients that occurred in our institution between July 2019 and January 2020. All patients underwent a conventional mycological study. The identification of fungi isolates was confirmed by MALDI-TOF MS and sequencing of the ribosomal DNA. T. benhamiae was identified as the etiological agent, whose epidemiological link in all cases was the contact with Guinea pigs. This is the first description of infections caused by T. benhamiae in Argentina. This dermatophyte can be misidentified as other more frequent dermatophytes when performing conventional studies. Molecular technology should be used to reach a definitive diagnosis. It is important to have epidemiological data from patients such as contact with non-traditional pets, especially Guinea pigs, for an adequate presumptive diagnosis of this dermatophytosis.