Actualización en taxonomía, diagnóstico y tratamiento de las dermatofitosis / Update on taxonomy, diagnosis and treatment

Los dermatofitos son un grupo de hongos responsables de las dermatofitosis o tiñas, pudiendo afectar piel, uñas y pelo. En la actualidad están constituidos por los géneros Epidermophyton, Trichophyton, Microsporum, Arthroderma, Paraphyton, Lophophyton y Nannizzia. El examen microscópico directo y el cultivo en agar siguen siendo el estándar de oro para la identificación, sin embargo, en ocasiones se requiere de la biología molecular para poder corroborar una determinada especie. Dependiendo de la localización, del número de lesiones y de la extensión, el tratamiento de las dermatofitosis puede ser tópico o sistémico. Trichophyton indotineae y T tonsurans pueden expresar resistencia a la terbinafina y azoles, respectivamente.

Dermatophytes are a group of fungi responsible for dermatophytosis or ringworm, which can affect the skin, nails and hair. Currently, they are assembled by the genera Epidermophyton, Trichophyton, Microsporum, Arthroderma, Paraphyton, Lophophyton and Nannizzia. Direct microscopic examination and culture on agar remain the gold standard for identification, however, molecular biology is sometimes required to confirm a certain species. Depending on the location, the number of lesions and the extension, the treatment of dermatophytosis can be topical or systemic. Trichophyton indotineae and T tonsurans can express resistance to terbinafine and azoles, respectively.

The activity of propolis against pathogenic fungi isolated from human infections

Abstract Propolis is a resinous hive product collected by bees from the buds or other parts of plants. It is known for having various biological properties, including antifungal activity. Among the substances present in propolis, flavonoids and phenolic acids and their esters are responsible for its antifungal properties. This means that propolis is ideal for use as an antifungal agent in alternative medicine to treat a number of both topical and systemic infections caused by Candida species and other yeast-like fungi, dermatophyte and nondermatophyte moulds, without the serious side effects typical of synthetic treatment. It is also active against strains of fungi that are resistant to polyenes and azoles, the classes of drugs most commonly used to treat fungal infections. In this article, we review current knowledge about the activity of propolis from different parts of the world and its components in vitro and in vivo against pathogenic fungi isolated from human infections. The article also indicates the possible mechanism of antifungal activity of propolis and its components.

DNA topoisomerase 2 gene polymorphism in dermatophytes.

BACKGROUND: Dermatophytes are a group of keratinophilic fungi of medical importance. Despite a relatively long history of molecular taxonomic studies, there is still a need for information on genetic polymorphism in wider variety of genomic loci. OBJECTIVES: Our goal was to study partial DNA topoisomerase 2 gene (TOP2) polymorphism in dermatophytes. METHODS: We performed DNA sequencing of TOP2 in 26 dermatophyte species along with ribosomal internal transcribed spacer (ITS) sequencing. RESULTS: The number of polymorphic sites in TOP2 data set was similar to that one in ITS data set. Nannizzia species formed paraphyletic group in TOP2 tree. Trichophyton simii was paraphyletic in concatenated TOP2-ITS tree, one of its two clades contained solely Iranian isolates. CONCLUSIONS: Our results revealed several unresolved problems in the taxonomy of dermatophytes, including probable polyphyly of the genus Nannizzia and the species T simii.

Antioxidant and antifungal activities of marrubiin, extracts and essential oil from Marrubium vulgare L. against pathogenic dermatophyte strains.

OBJECTIVE: Medicinal plants extracts and plant-derived compounds are one of the natural sources for discovering new antifungal agents, the objectives of this work were to investigate for the first time the antidermatophytic, antipathogenic activities of methanol, acetone extracts, and essential oil of Marrubium vulgare L. grown in Tunisia and its active compound marrubiin on pathogenic for animals and humans, such as some dermatophytes and pathogenic for plants, and to evaluate antioxidant activities of different extracts with consideration to their chemical compositions. MATERIAL AND METHODS: Acetone and methanol extracts were evaluated by HPLC, the essential oil was also analyzed by GC/MS. PCL assay was used to determine the antioxidant activity. RESULTS: Results showed that methanol and acetone extracts exhibited a significant antioxidant activity (261.41 and 272.90µmol TE/g respectively), while the lowest one was observed in the case of marrubiin and essential oil. The antifungal activity of different extracts, marrubiin and essential oil at two concentrations (20 and 100µg/mL) were screened against the dermatophytes fungi Microsporum gypseum, Microsporum canis, Arthroderma cajetani, Trichophyton mentagrophytes, Trichophyton tonsurans, Epidermophyton floccosum and against two fungi strains (Botrytis cinerea, Pythium ultimum). Among tested extracts, marrubiin at 100µg/mL showed about 50% inhibition for T. mentagrophytes and E. floccosum. The anti-phytopathogenic activity was also carried out, only marrubiin had in activity against B. cinerea at the highest dose (32.40%), while methanol extract of M.vulgare and marrubiin are able to increase the mycelial growth of P. ultimum at the highest concentration (45.15 and 40.30% respectively). CONCLUSION: In our study, we conclude that M.vulgare and marrubiin can be used as natural antioxidants and antifungal agent for treatment of skin dermatophyte infections.

Lineages Within the Trichophyton rubrum Complex.

The most important species of the Trichophyton rubrum group are T. rubrum, causing mainly skin and nail infections, and T. violaceum which is mostly scalp-associated. The status of a third species, T. soudanense, has been under debate. With a polyphasic approach, using molecular phylogenetic techniques, MALDI-TOF mass spectrometry and physiological and morphological analysis, we re-evaluated the T. rubrum complex. Our results support four genetic lineages within the complex each with a distinct morphology and identifiable via MALDI-TOF MS: T. rubrum, T. violaceum, T. soudanense and the T. yaoundei clade. However, ITS and Bt2 sequencing data could not confirm these taxa as four monophyletic species. Our results also suggest that strains formerly identified as T. kuryangei and T. megninii should be considered in future taxonomic studies.

Fast identification of dermatophytes by MALDI-TOF/MS using direct transfer of fungal cells on ground steel target plates.

Dermatophytes cause human infections limited to keratinised tissues. We showed that the direct transfer method allows reliable identification of non-dermatophytes mould and yeast by MALDI-TOF/MS. We aimed at assessing whether the direct transfer method can be used for dermatophytes and whether an own mass spectra library would be superior to the Bruker library. We used the Bruker Biotyper to build a dermatophyte mass spectra library and assessed its performance by 1/testing a panel of mass spectrum produced with strains genotypically identified and, 2/comparing MALDI-TOF/MS identification to morphology-based methods. Identification of dermatophytes using the Bruker library is poor. Our library provided 97% concordance between ITS sequencing and MALDI-TOF/MS analysis with a panel of 1104 spectra corresponding to 276 strains. Direct transfer method using unpolished target plates allowed proper identification of 85% of dermatophytes clinical isolates most of which were common dermatophytes. A homemade dermatophyte MSP library is a prerequisite for accurate identification of species absent in the Bruker library but it also improves identification of species already listed in the database. The direct deposit method can be used to identify the most commonly found dermatophytes such as T. rubrum and T. interdigitale/mentagrophytes by MALDI-TOF/MS.

Epidemiology of dermatophyte infections among school children in Menoufia Governorate, Egypt.

Most superficial mycotic infections of human skin are due to dermatophytes. Children are frequently affected due to different predisposing factors, particularly overcrowding in classrooms. This study aimed to estimate the prevalence of dermatophytes infections and their related risk factors among school children in Menoufia Governorate, Egypt. Six public primary and preparatory schools were randomly selected and their pupils (n = 3464) were asked to complete a predesigned questionnaire covering both personal data and suspected risk factors for superficial dermatophyte infections. The children were also examined for dermatological diseases. Any suspected lesions were biopsied for mycological examination. The prevalence of clinically suspected dermatophytes infections was 1.41%, whereas the prevalence of culture confirmed cases was 0.98%. The most common clinical type was tinea capitis with a prevalence of 1.01%. Microsporum canis was the only isolated organism from the suspicious lesions with a 69.4% positivity rate. A higher prevalence was observed among boys, low socio-economic pupils and those with a family history of dermatophyte infections. Pet contact and sharing towels and caps among pupils were significant risk factors. Dermatophyte infection is still prevalent among basic school pupils. Fortunately, it is related to preventable risk factors. We recommend regular screening and use of educational health programmes for kids to control it.

In Vitro additive effect on griseofulvin and terbinafine combinations against multidrug-resistant dermatophytes

ABSTRACT Griseofulvin (GF) and terbinafine (TF) are commonly used drugs to treat dermatophytosis, a fungal infection of the skin. Today there is an increase in drug resistance to these antifungals which highlight the need for alternative synergistic therapies. Minimum Inhibitory Concentration (MIC) of GF and TF were determined against fungi clinical isolates from local hospitals with values ranging 0.03-2.0 µg mL-1 and 0.24-4.0 µg mL-1, respectively. A checkboard test was used to determine the combination of GF:TF which could induce an additive effect against the fungi isolates Multidrug-resistant isolates showed susceptibility after treatment with 16:2 µg mL-1 GF:TF. An MTT assay further verified that GF and TF combinations have greater additive effect against pathological and multidrug-resistant isolates than antifungals alone. Herein we disclose GF:TF combinations that could constitute as a possible new anti-dermatophyte therapy.

Detection of seasonal asymptomatic dermatophytes in Van cats

Abstract The Van cat is a domestic landrace found in the Van province of eastern Turkey. In this study, we aimed to determine the seasonal carriage of dermatophytes in Van cats without clinical lesions. A total of 264 hair specimens were collected from clinically healthy cats in and around the Van Province. Of these samples, 30.3% were obtained in spring, 30.6% in summer, 16.6% in autumn, and 22.3% in winter; 45.1% of samples were from male cats and the rest from female ones. Of the studied cats, 118 were younger than 1 year, 78 were 1–3 years old, and 68 were older than 3 years. The specimens were subjected to direct microscopic examination with 15% potassium hydroxide and cultured on Sabouraud dextrose agar and dermatophyte test medium supplemented with cycloheximide and chloramphenicol. Dermatophyte identification was carried out based on macroscopic and microscopic colony morphology, urease activities, in vitro hair perforation test, growth at 37 °C, and pigmentation on corn meal agar. Dermatophytes were isolated from 19 (7.1%) of the 264 specimens examined. The most frequently isolated fungi were Trichophyton terrestre (4.1%), followed by Microsporum gypseum (1.1%), M. nanum (1.1%), and T. mentagrophytes (0.7%), and these fungi may represent a health risk for humans in contact with clinically healthy Van cats. M. canis was not isolated from any of the specimens. Our results show no significant (p > 0.05) association between carriage of dermatophytes and the gender of cats. The carriage rate of dermatophytes was high in spring and winter, and the only possible risk factor for infection was age of the animal.

Dermatofitoses: agentes etiológicos, formas clínicas, terapêutica e novas perspectivas de tratamento / Dermatophytoses: etiologic agents, clinical forms, therapy and new perspectives of treatment

As dermatofitoses têm ocorrência mundial, sendo mais prevalentes em países de clima tropical e subtropical. Dados epidemiológicos indicam que essas micoses estão entre as infecções fúngicas de maior ocorrência. O quadro clínico mais comum de dermatofitose inclui despigmentação, placas anulares, prurido e perda de cabelo, com lesões tipicamente conhecidas como tineas, ocasionadas por fungos filamentosos dermatofíticos de três gêneros anamórficos: Microsporum, Trichophyton e Epidermophyton. O tratamento das dermatofitoses, em geral, está relacionado ao uso de antifúngicos tópicos e/ou sistêmicos, apresentando como problemática o surgimento de espécies multirresistentes. Esta revisão aborda as dermatofitoses e seus agentes etiológicos de forma aprofundada em aspectos epidemiológicos, apresentando a importância clínica do tema, com ênfase na causa, prevenção, tratamento e prognóstico dessa micose cutânea (AU)

Dermatophytoses have worldwide occurrence with higher prevalence in tropical and subtropical countries. Epidemiological data show that these mycoses are among the most frequent fungal infections. The most common symptoms of dermatophytoses include depigmentation, annular plaques, itching and hair loss, with lesions such as tinea, caused by dermatophytic filamentous fungi of three anamorphic genera: Microsporum, Trichophyton and Epidermophyton. Topical and/or systemic antifungalmedications are used in the treatment of dermatophytoses in general, resulting in problems such as the emergence of multidrug-resistant species. This review discusses dermatophytoses and their etiological agents with a focus on epidemiological aspects, presenting the clinical importance of the issue, with emphasis on cause, prevention, treatment and prognosis of this skin mycosis (AU)

Dermatophytosis and immunovirological status of HIV-infected and AIDS patients from Sao Paulo city, Brazil.

Over the past decades, more people became infected with human immunodeficiency virus (HIV) and developed acquired immunodeficiency syndrome (AIDS). Because of that the incidence of fungal infections rose dramatically. It happened because this virus can modify the course of fungal diseases, leading to altered clinical pictures. The aim of this study was to evaluate epidemiological and biological aspects of dermatophytosis in HIV-positive and AIDS patients living in the city of São Paulo, Brazil. A total of 84 (44 HIV-positive and 40 AIDS) patients were enrolled in this study. The patients were tested for dermatophyte infections, as well as for the CD4(+) /CD8(+) and HIV viral load counts. Tinea unguium was most frequently observed in AIDS patients, whereas Tinea pedis was mostly observed in HIV-positive patients. The most frequent dermatophyte species was Trichophyton rubrum. CD4(+) counts and CD4(+) /CD8(+) ratios were not associated with a higher risk for dermatophytosis. On the other hand, viral load higher than 100 000 copies/ml was associated with a higher frequency of dermatophytosis. The results suggest to that although dermatophytosis is common in HIV-positive and AIDS patients, the degree of immunosuppression does not seems to correlate with increased risk of this fungal infection. In addition, high viral load as a predictive risk factor for dermatophyte infection should be subject of further evaluations.

Distribution ofddermatophytes from soils of urbn and rural areas of cities of paraiba state, Brazil / Distribuicao de dermatofitos isolados de solos de cidades do Estado da Paraiba, Brasil

SUMMARY The dermatophytes, keratinophilic fungi, represent important microorganisms of the soil microbiota, where there are cosmopolitan species and others with restricted geographic distribution. The aim of this study was to broaden the knowledge about the presence of dermatophytes in soils of urban (empty lots, schools, slums, squares, beaches and homes) and rural areas and about the evolution of their prevalence in soils of varying pH in cities of the four mesoregions of Paraiba State, Brazil. Soil samples were collected from 31 cities of Paraiba State. Of 212 samples, 62% showed fungal growth, particularly those from the Mata Paraibana mesoregion (43.5%), which has a tropical climate, hot and humid. Soil pH varied from 4.65 to 9.06, with 71% of the growth of dermatophytes occurring at alkaline pH (7.02 - 9.06) (ρ = 0.000). Of 131 strains isolated, 57.3% were geophilic species, particularly Trichophyton terrestre (31.3%) and Mycrosporum gypseum (21.4%). M. nanum and T. ajelloi were isolated for the first time in Paraiba State. The zoophilic species identified were T. mentagrophytes var. mentagrophytes (31.3 %) and T. verrucosum (7.6 %), and T. tonsurans was isolated as an anthropophilic species. The soils of urban areas including empty lots, schools, slums and squares of cities in the mesoregions of Paraiba State were found to be the most suitable reservoirs for almost all dermatophytes; their growth may have been influenced by environmental factors, soils with residues of human and/or animal keratin and alkaline pH. .

RESUMO Os dermatófitos, fungos queratinofílicos, representam importantes microrganismos da microbiota do solo, onde existem espécies cosmopolitas e outras de distribuição geográfica restrita. Este estudo teve como objetivo ampliar o conhecimento da distribuição de dermatófitos do solo proveniente de áreas urbanas (terrenos baldios, escolas, favelas, praças, praias e residências) e rurais de quatro mesorregiões paraibanas e da influência do pH na adaptação desse grupo de fungos. Amostras de solos urbanos e rurais foram coletadas de 31 cidades do estado da Paraíba, Brasil. De 212 amostras 62% apresentaram crescimento fúngico, destacando-se a Mesorregião da Mata Paraibana (43.5%), a qual apresenta clima tropical, quente e úmido. O pH das amostras de solo variou de 4.65 a 9.06, com crescimento de 71% dos dermatófitos em pH alcalino (7.02 - 9.06) (ρ = 0.000). Das 131 cepas isoladas 57.3% eram espécies geofílicas, destacando-se Trichophyton terrestre (31.3%) e Microsporum gypseum (21.4%). M. nanum e T. ajelloi foram isolados pela primeira vez no estado da Paraíba. Entre as espécies zoofílicas foram identificadas T. mentagrophytes var. mentagrophytes (31.3%) e T. verrucosum (7.6%) e como espécie antropofílica foi isolada T. tonsurans. Os solos de terrenos baldios, escolas, favelas e praças de cidades paraibanas são os reservatórios mais adequados dos dermatófitos, cujo crescimento pode ter sido influenciado por fatores ambientais, solos com resíduos de queratina humana e ou animal e pH alcalino. .

Dermatophytosis diagnosed at the Evandro Chagas Institute, Pará, Brazil

Dermatophytosis is caused by a dermatophyte fungus that affects the stratum corneum and keratinized tissue. Dermatophyte fungus has been reported worldwide as the causative agent of dermatophytosis, but the etio-epidemiological aspects of these mycoses in the state of Pará remain unknown. The purpose of this study was to describe the etio-epidemiological profile of dermatophytosis diagnosed in patients at the Evandro Chagas Institute from May 2005 to June 2006. A total of 494 patients were admitted, and their samples were collected, submitted for direct microscopic examination using 20% KOH and cultured in Sabouraud and Mycosel medium. The identification was based in macro and microscopic characteristics. Direct examinations were positive in 13% (66/494) of the patients, and agent isolation by cultivation of the biological sample was successful in 4% (20/494), with a high prevalence of T. mentagrophytes (40%; 8/20). Dermatophytosis was more frequent in women (58%; 38/66). Fifty-two percent (21/38) of the cases were children with an average age of 8 years. The most frequent clinical presentation was Tinea corporis (55%, 36/66). For the cases in which the dermatophyte agent was not isolated, we discuss the factors that may be interfering with isolation. Tinea corporis occurred more frequently observed when T. mentagrophytes and T. rubrum were the major etiologic agents.

Majocchi's granuloma in solid organ transplant recipients.

Superficial fungal infections are fairly prevalent in transplant recipients and the incidence increases with more intense graft-conserving immunosuppressive therapy. Majocchi's granuloma is a deep folliculitis caused by dermatophytes that involves deeper layers of the dermis. Only a few case reports of the condition have been documented in transplant recipients. After an extensive review of the medical literature, 21 cases were retrieved and are summarized here, together with a new case that occurred in a recent heart transplant recipient from our institution. This report aims to provide a comprehensive analysis of Majocchi's granuloma in solid organ transplant (SOT) recipients, with special focus on potential risk factors, offending pathogens, clinical presentation, therapeutic approaches, and outcome. General observations are presented emphasizing the relevance of close clinical and dermatologic follow-up in high-risk SOT patients with specific comments regarding treatment regimens and outcomes.

Antifungal activity of the clove essential oil from Syzygium aromaticum on Candida, Aspergillus and dermatophyte species.

The composition and antifungal activity of clove essential oil (EO), obtained from Syzygium aromaticum, were studied. Clove oil was obtained commercially and analysed by GC and GC-MS. The EO analysed showed a high content of eugenol (85.3 %). MICs, determined according to Clinical and Laboratory Standards Institute protocols, and minimum fungicidal concentration were used to evaluate the antifungal activity of the clove oil and its main component, eugenol, against Candida, Aspergillus and dermatophyte clinical and American Type Culture Collection strains. The EO and eugenol showed inhibitory activity against all the tested strains. To clarify its mechanism of action on yeasts and filamentous fungi, flow cytometric and inhibition of ergosterol synthesis studies were performed. Propidium iodide rapidly penetrated the majority of the yeast cells when the cells were treated with concentrations just over the MICs, meaning that the fungicidal effect resulted from an extensive lesion of the cell membrane. Clove oil and eugenol also caused a considerable reduction in the quantity of ergosterol, a specific fungal cell membrane component. Germ tube formation by Candida albicans was completely or almost completely inhibited by oil and eugenol concentrations below the MIC values. The present study indicates that clove oil and eugenol have considerable antifungal activity against clinically relevant fungi, including fluconazole-resistant strains, deserving further investigation for clinical application in the treatment of fungal infections.

Comparison of in vitro activity of five antifungal agents against dermatophytes, using the agar dilution and broth microdilution methods / Comparação da atividade in vitro de cinco agentes antifúngicos para dermatófitos, usando os métodos de diluição em ágar e microdiluição em caldo

The purpose of this study was to compare the agar dilution and broth microdilution methods for determining the minimum inhibitory concentration (MIC) of fluconazole, itraconazole, ketoconazole, griseofulvin and terbinafine for 60 dermatophyte samples belonging to the species Trichophyton rubrum, Trichophyton mentagrophytes and Microsporum canis. The percentage agreement between the two methods, for all the isolates with < 2 dilutions that were tested was 91.6 percent for ketoconazole and griseofulvin, 88.3 percent for itraconazole, 81.6 percent for terbinafine and 73.3 percent for fluconazole. One hundred percent agreement was obtained for Trichophyton mentagrophytes isolates evaluated with ketoconazole and griseofulvin. Thus, until a reference method for testing the in vitro susceptibility of dermatophytes is standardized, the similarity of the results between the two methods means that the agar dilution method may be useful for susceptibility testing on these filamentous fungi.

O propósito do presente trabalho foi comparar os métodos de diluição em ágar e diluição em caldo para a determinação de concentração inibitória mínima de fluconazol, itraconazol, cetoconazol, griseofulvina e terbinafina para 60 amostras de dermatófitos pertencentes às espécies, Trichophyton rubrum, Trichophyton. mentagrophytes e Microsporum canis. A porcentagem de acordo entre os dois métodos para todos os isolados testados considerando-se valores < 2 diluições, foram de 91,6 por cento para cetoconazol e para griseofulvina, de 88,3 por cento para itraconazol, de 81,6 por cento para terbinafina e de 73,3 por cento para fluconazol. Uma concordância de 100 por cento foi obtido para isolados de Trichophyton mentagrophytes avaliados com cetoconazol e griseofulvina. Desta forma, até que um método de referência seja padronizado para testar a suscetibilidade in vitro para os dermatófitos, os resultados semelhantes encontrados para os dois métodos fazem com que o método de diluição em ágar possa ser útil no teste de suscetibilidade para estes fungos filamentosos.

The new species concept in dermatophytes-a polyphasic approach.

The dermatophytes are among the most frequently observed organisms in biomedicine, yet there has never been stability in the taxonomy, identification and naming of the approximately 25 pathogenic species involved. Since the identification of these species is often epidemiologically and ethically important, the difficulties in dermatophyte identification are a fruitful topic for modern molecular biological investigation, done in tandem with renewed investigation of phenotypic characters. Molecular phylogenetic analyses such as multilocus sequence typing have had to be tailored to accommodate differing the mechanisms of speciation that have produced the dermatophytes that are commonly seen today. Even so, some biotypes that were unambiguously considered species in the past, based on profound differences in morphology and pattern of infection, appear consistently not to be distinct species in modern molecular analyses. Most notable among these are the cosmopolitan bane of nails and feet, Trichophyton rubrum, and the endemic African agent of childhood tinea capitis, Trichophyton soudanense, which are effectively inseparable in all analyses. The molecular data require some reinterpretation of results seen in conventional phenotypic tests, but in most cases, phylogenetic insight is readily integrated with current laboratory testing procedures.

Arthroderma gypseum y su anamorfo en el jardín central de la Universidad Nacional de Tucumán, Argentina / Artroderma gypseum and its anamorph from the central garden of the Universidad Nacional de Tucuman, Argentina

Con el objeto de contribuir al conocimiento de la micobiota en áreas públicas, en especial en la búsqueda de propágulos infectivos para el hombre y los animales de dermatofitos geofílicos desde sus fuentes saprofíticas, se estudiaron en el lapso de 2 años, 8 muestras superficiales de suelo (una cada 3 meses) desde los jardines centrales de la Universidad Nacional de Tucumán mediante la Técnica de Vanbreuseghem, usando pelos de niños como anzuelo queratínico. Las 8 muestras sembradas en 24 placas de Petri, presentaron todas al cabo de 25-30 días la presencia de Arthroderma gypseum y su anamorfo Microsporum gypseum como único dermatofito presente. Los cultivos en Sabouraud glucosado y en Sabouraud al 10 por ciento (medio deTakashio), permitieron identificar las cepas típicas del anamorfo. La presencia y prevalencia en el tiempo de este agente en las muestras colectadas en dependencias universitarias rodeadas de aulas, laboratorios y oficinas, posee un impacto en salud pública y ambiental por su conocido oportunismo en pacientes inmunocompetentes e inmunocomprometidos.

With the purpose of knowing the presence of mycobiota in public areas, mainly in the search of propagules of geophilic dermatophytes which are infective for man and animals from their saprophytic sources, 8 superficial samples of soil (every 3 month), collected from the central gardens of the Universidad Nacional de Tucumán were studied during a 2-year period, by using the Vanbreuseghem Technique which employs children hair as a keratinic bait. The overall 8 samples sowed on 24 Petri plates revealed after 25-30 days the presence of Arthroderma gypseum and its anamorph Microsporum gypseum as the only dermatophyte present. Cultures in glucose Sabouraud and in 10 percent Sabouraud (Takashio medium), allowed the identification of the typical strains of the anamorph. Presence and prevalence in time of this agent in samples collected from university buildings surrounded by classrooms, laboratories and offices means an impact on public and environmental health due to its well known opportunism in immunocompetent and immunocompromised patients.

Phylogeny and taxonomy of the family Arthrodermataceae (dermatophytes) using sequence analysis of the ribosomal ITS region.

The internal transcribed spacer (ITS) region, covering the ITS1, ITS2 and 5.8S ribosomal DNA was used to evaluate phylogenetic relationships within the fungal family Arthrodermataceae. Sequences of variable length, ranging between 522 and 684 base pairs were aligned. An unrooted consensus tree based on parsimony analysis showed Trichophyton to be polyphyletic, and Microsporum to be paraphyletic. Non-monophyly of these two genera is in conflict with traditional classification. But this relation is not strongly supported by bootstrap analysis. Phylogenetic analysis showed that the two known members of the genus Epidermophyton grouped widely apart from each other. Within Trichophyton, our results suggest a separation of human pathogenic species and primarily geophilic species. Bootstrap support for these two groups is fairly high and both groups are recognized by current taxonomy. Three lineages were revealed within the T. mentagrophytes species complex. Microsporum canis, M. audouinii and M. equinum were found to be closely related. The topology of the tree was robust to various methods of analysis (parsimony and distance) and a different weighting scheme. Weighting of transversions over transitions did not improve the status of poorly supported branches of the tree.