Poloxamer-enhanced solubility of griseofulvin and its related antifungal activity against Trichophyton spp

Abstract Poorly water-soluble drugs, such as the antifungal drug griseofulvin (GF), exhibit limited bioavailability, despite their high membrane permeability. Several technological approaches have been proposed to enhance the water solubility and bioavailability of GF, including micellar solubilization. Poloxamers are amphiphilic block copolymers that increase drug solubility by forming micelles and supra-micellar structures via molecular self-association. In this regard, the aim of this study was to evaluate the water solubility increment of GF by poloxamer 407 (P407) and its effect on the antifungal activity against three Trichophyton mentagrophytes and two T. rubrum isolates. The GF water solubility profile with P407 revealed a non-linear behavior, well-fitted by the sigmoid model of Morgan-Mercer-Flodin. The polymer promoted an 8-fold increase in GF water solubility. Fourier-transform infrared (FT-IR) spectroscopy, differential scanning calorimetry (DSC), and 2D nuclear magnetic resonance (NMR Roesy) spectroscopy suggested a GF-P407 interaction, which occurs in the GF cyclohexene ring. These results were supported by an increase in the water solubility of the GF impurities with the same molecular structure. The MIC values recorded for GF ranged from 0.0028 to 0.0172 mM, except for T. Mentagrophytes TME34. Notably, the micellar solubilization of GF did not increase its antifungal activity, which could be related to the high binding constant between GF and P407.

Chemical composition and antifungal activity of essential oil from Eucalyptus smithii against dermatophytes

ABSTRACT INTRODUCTION: In this study, we evaluated the chemical composition of a commercial sample of essential oil from Eucalyptus smithii R.T. Baker and its antifungal activity against Microsporum canis ATCC 32903, Microsporum gypseum ATCC 14683, Trichophyton mentagrophytes ATCC 9533, T. mentagrophytes ATCC 11480, T. mentagrophytes ATCC 11481, and Trichophyton rubrum CCT 5507. METHODS: Morphological changes in these fungi after treatment with the oil were determined by scanning electron microscopy (SEM). The antifungal activity of the oil was determined on the basis of minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) values. RESULTS: The compound 1,8-cineole was found to be the predominant component (72.2%) of the essential oil. The MIC values of the oil ranged from 62.5μg·mL−1 to >1,000μg·mL−1, and the MFC values of the oil ranged from 125μg·mL−1 to >1,000μg·mL−1. SEM analysis showed physical damage and morphological alterations in the fungi exposed to this oil. CONCLUSIONS: We demonstrated the potential of Eucalyptus smithii essential oil as a natural therapeutic agent for the treatment of dermatophytosis.

Estudio taxonómico de aislamientos clínicos de Trichophyton en Rosario, Argentina / Taxonomic study of clinical isolates of Trichophyton in Rosario, Argentina

Debido al pleomorfismo y la variabilidad cultural que presentan las especies del género Trichophyton, los métodos de identificación basados exclusivamente en caracteres morfológicos a menudo no son suficientes para su clasificación. El objetivo de este estudio fue probar un conjunto de métodos fenotípicos para identificar aislamientos fúngicos pertenecientes al género Trichophyton empleando una técnica de taxonomía molecular como método de referencia. Se utilizaron 56 aislamientos clínicos y 6 cepas de referencia, con los que se realizaron estudios macro y micromorfológicos, así como las siguientes pruebas bioquímicas y fisiológicas: perforación del pelo in vitro, requerimientos nutricionales en medios agar Trichophyton, producción de ureasa y crecimiento en el medio agar púrpura de bromocresol-leche-glucosa (APBC-L-G). A su vez se realizó una PCR fingerprinting utilizando el cebador simple (GACA)4. Como resultado de la reacción de PCR se observaron perfiles específicos bien diferenciables para Microsporum canis, Epidermophyton fl occosum, Trichophyton rubrum y Trichophyton interdigitale, pero un mismo perfil para Arthroderma benhamiae y Trichophyton erinacei. Del total de los aislamientos clínicos evaluados, 39 coincidieron con el perfil de T. rubrum, 13 con el de A. benhamiae y 4 con el de T. interdigitale. El ensayo fenotípico más útil para diferenciar T. rubrum del complejo T. mentagrophytes fue la alcalinización del medio APBC-L-G. Con las pruebas fenotípicas se pudo diferenciar T. rubrum de los aislamientos del complejo T. mentagrophytes, pero no las especies pertenecientes a dicho complejo. La técnica molecular permitió caracterizar tanto los aislamientos de T. rubrum como los pertenecientes al complejo T. mentagrophytes, que en nuestro estudio correspondieron a T. interdigitale y Trichophyton sp. anamorfo de A. benhamiae.

Due to the pleomorphism and cultural variability displayed by species of the genus Trichophyton, the identification methods based solely on morphological features are usually insufficient for their classification. The goal of the present work was to test a set of phenotypic methods in order to identify fungal isolates that belong to the aforementioned genus. These methods were based on a molecular taxonomic technique used as standard. Clinical isolates (56) were used as samples along with 6 reference strains. Macro and micromorphological studies were performed as well as biochemical and physiological tests such as in vitro hair perforation, nutritional requirements in Trichophyton agar media, urease production and growth on bromocresol purple-milk solids-glucose (BCP-MS-G) agar. Additionally, PCR fingerprinting using the (GACA)4 primer was employed. As a result of the PCR method, specific profiles were observed for Microsporum canis, Epidermophyton floccosum, Trichophyton rubrum and Trichophyton interdigitale. Identical profiles were obtained for Arthroderma benhamiae y Trichophyton erinacei. Of the total number of clinical isolates, 39 matched the T. rubrum profile while 13 corresponded to A. benhamiae and 4 to T. interdigitale. The most useful phenotypic test to differentiate between T. rubrum and T. mentagrophytes complex strains was alkalinization of the BCP-MS-G medium. Phenotypic tests did not allow differentiation among the T. mentagrophytes complex species. On the other hand, the molecular technique allowed characterization of T. rubrum isolates as well as of those observed in our study and included in the T. mentagrophytes complex: T. interdigitale and Trichophyton sp. , the anamorph of A. benhamiae.

Microepidemia familiar por Trichophyton tonsurans / Trichophyton tonsurans in a family microepidemic

Trichophyton tonsurans é um fungo dermatófito antropofílico de alta transmissibilidade que invade tecidos queratinizados. Relatamos um caso de microepidemia familiar causada por esse dermatófito no qual, apesar das ótimas condições de higiene, o fungo se manteve viável por vários anos, disseminando-se para todos os membros da família. A hipótese de que estivesse sendo mantido na residência da família foi confirmada após análise de amostras do domicílio, em que foram isoladas e identificadas culturas puras do fungo. Após o diagnóstico, a residência foi desinfetada e todos os membros da família receberam tratamento oral concomitantemente.

Trichophyton tonsurans is a highly transmissible anthropophilic dermatophyte fungus, which invades keratinized tissues. This study reports a case of family microepidemic caused by this dermato phyte. Despite their excellent hygiene conditions, it remained active for several years, spreading to all family members. The hypothesis that the fungus was being kept alive in the family home was confirmed after samples collected from it were analyzed. Pure cultures of the fungus were isolated and identified. After diagnosis, the house was disinfected with concomitant oral treatment for all family members.

In vitro susceptibility testing of dermatophytes isolated in Goiania, Brazil, against five antifungal agents by broth microdilution method / Teste de suscetibilidade in vitro de dermatófitos isolados em Goiânia, Brasil, contra cinco agentes antifúngicos pelo método de microdiluição em caldo

The antifungal activities of fluconazole, itraconazole, ketoconazole, terbinafine and griseofulvin were tested by broth microdilution technique, against 60 dermatophytes isolated from nail or skin specimens from Goiania city patients, Brazil. In this study, the microtiter plates were incubated at 28 ºC allowing a reading of the minimal inhibitory concentration (MIC) after four days of incubation for Trichophyton mentagrophytes and five days for T. rubrum and Microsporum canis. Most of the dermatophytes had uniform patterns of susceptibility to the antifungal agents tested. Low MIC values as 0.03 µg/mL were found for 33.3 percent, 31.6 percent and 15 percent of isolates for itraconazole, ketoconazole and terbinafine, respectively.

Atividades antifúngicas de fluconazol, itraconazol, cetoconazol, terbinafina e griseofulvina foram testadas pelo método de microdiluição em caldo contra 60 isolados de dermatófitos. Os resultados mostraram que todos os isolados produziram crescimento claramente detectável a 28 ºC e a concentração inibitória mínima (CIM) foi determinada após quatro dias de incubação para Trichophyton mentagrophytes e cinco dias para T. rubrum e Microsporum canis. A maioria dos isolados teve um padrão uniforme de suscetibilidade para os agentes antifúngicos testados. Baixos valores de CIM como 0,03 µg/mL foram encontrados para 33,3 por cento, 31,6 por cento e 15 por cento dos isolados para itraconazol, cetoconazol e terbinafina, respectivamente.

Análisis fenotípico del complex Trichophyton rubrum en los medios de Sabouraud, Lactrimel y la técnica de Fischer & Kane: una experiencia regional / Phenotipic analysis of the Trichophyton rubrum complex in Sabouraud’ s dextrose agar, Lactrimel agar and the Fischer & Kane technique: A regional experience

Con el propósito de comparar el rendimiento y la eficiencia de los medios utilizados de rutina en el laboratorio de Micología para la identificación de las especies que integran el complex T. rubrum presentes en la V Región, Chile, seleccionamos: Agar glucosa Sabouraud (SDA), Agar Lactrimel (AL) y el medio sólido leche, glucosa, adicionado con el indicador de púrpura de bromocresol (Fischer & Kane, 1971) (BCP-MS-G). Estos fueron probados en 304 cepas consideradas como T. rubrum en el medio SDA, provenientes de pacientes dermatológicos. Los parámetros que se consideraron fueron rango de crecimiento, pigmentación al reverso de las colonias y presencia de fructificaciones. Las variedades del complex identificadas fueron T. rubrum var. algodonosa (72,4 por ciento) y T. rubrum var. granular (14,5 por ciento) además de integrantes del complex T. mentagrophytes (13,2 por ciento) que no se consideraron en el estudio. La zona anatómica más afectada fueron las uñas de los pies (80,7 por ciento). La fructificación en los 3 medios fue considerada como el gold standard y en base a este criterio se estableció su sensibilidad y especificidad, obteniéndose para la var. granular una especificidad de un 100, 98,6 y 83,9 por ciento en BCP-MS-G, AL y SDA, respectivamente. Para la var. algodonosa, la mayor sensibilidad se obtuvo en BCP-MS-G (71,9 por ciento), pero con una nula especificidad, por lo que se sugiere considerar el rango de crecimiento limitado a los 7 días y la pigmentación al reverso de la colonia en este medio. La identificación fue complementada con la prueba de la ureasa, que fue 100 por ciento negativa para todo el complex T. rubrum. Se sugiere el uso del medio de Fischer & Kane en conjunto con AL y SDA para diferenciar las variedades de este complex.

The following media Sabouraud·s dextrose agar (SDA), Lactrimel Agar and BCP-Milk solids glucose agar(Fischer & Kane, 1971) (BCP-MS-G) were selected to evaluate the performance and the efficiency of the routine media used in mycological laboratory with the purpose of identifying the species that conformed T. rubrum complex in the V Region of Chile. These were tested in 304 strains considered as T. rubrum in the SDA media, obtained from dermatological patients. The following parameters were used: the radial growth of the colonies,the pigmentation at the back of the plates and the presence of fructification. T. rubrum variety downy (72,4 percent and T. rubrum variety granular (14,5 percent) were the only variants identified and T. mentagrophytes (Robin) Blanchard (13,2 percent), that were not consider in this study. The mosts affected anatomic zones were the toe nails (68,9 percent). In the three media used, we considered the presence of fructifications as the gold standard and based on this criteria we evaluated the sensibility and specificity of them.For the variant granular we obtained a specificity of 100, 98,6 y 83,9 percent en BCP-MS-G, AL y SDA, respectively. For the variant downy, the greatest specificity was obtained in BCP-MS-G 71,9 percent,but with a null specificity, a cause of this situation we propose to considerer the restricted radial growth of colonies on the seventh day and the red pigmentation at the back of the plates in this media. The identification of the complex was complemented by theurea test, that was negative for the whole complex. The use of Fischer and Kane media in combination with AL and SDA is suggested for the differentiation of the varieties of this complex.

Ocorrência de dermatófitos em amostras de unhas, pés e mãos coletadas de estudantes universitários / Occurrence of dermatophyte, in nails, feet and hands of universitary students

Este trabalho teve como objetivo, avaliar a presença de dermatófitos, especificamente em unhas, pés e mãos de estudantes universitários com e sem lesões sugestivas de dermatofitose. Foram coletadas 280 amostras dessas regiões, das quais 31 (11,1 por cento) apresentaram positividade apenas pelo exame direto, e 20 (7,1 por cento) tiveram, além do exame direto positivo, crescimento de dermatófito, mediante cultivo da amostra biológica. T. rubrum foi o dermatófito isolado com maior freqüência (80 por cento), seguido por T. mentagrophytes (20 por cento). Considerando os sítios analisados neste trabalho, a ocorrência de dermatófitos foi observada em 10,4 por cento nas unhas dos pés, 5 por cento nas escamas de pés, 2,5 por cento nas unhas das mãos e apenas 0,4 por cento nas escamas das mãos.

Onychomycosis in Ceará (Northeast Brazil): epidemiological and laboratory aspects

Knowledge of epidemiological and mycological characteristics of onychomycosis has been noted by many authors as being an important tool for control of these fungal infections. This study seeks to improve knowledge of onychomycosis epidemiology and mycological features. Samples were taken from infected fingernails and toenails of 976 patients undergoing treatment at a respected Dermatology Center in Ceará, Fortaleza, CE, Brazil. Specimens from 512 patients (52 percent) were positive for onychomycosis. From the culture-positive samples, yeasts of the genus Candida (C. albicans, C. tropicalis, C. krusei, C. parapsilosis) were dominant. The dermatophytes isolated (Trichophyton rubrum, T. tonsurans, T. mentagrophytes var. mentagrophytes) were dominant in 46 patients (12.99 percent). The mould Fusarium spp. was isolated from 29 patients (8.19 percent). Yeast of the genus Candida is the main causal factor in onychomycosis in our region. Also, the study showed the importance of performing direct examination and culture in diagnosis of onychomycosis.

Dermatomycosis in and around Aurangabad.

A total of 175 cases of dermatophytoses were studied. Out of all the clinical types, Tinea corporis (T. corporis) was found to be the predominant clinical type (24.57%) followed by tinea cruris (T. cruris) (22.28%). Incidence of Tinea barbae (T. barbae) and Tinea imbricata (T. imbricata) was the least (2.85%) and 0.57% respectively. Out of 175 cases of dermatophytoses, 66 (37.71%) cases were positive on microscopic examination, out of which 27 (40.90%) cases were positive by culture also. Out of the 175 cases of dermatophytoses, 109 (62.28%) were engative on microscopic examination, out of which 13 (11.92%) were culture positive. In this study, Trichophyton was the commonest genus of dermatophyte isolated, with Trichophyton rubrum (T. rubrum) being the commonest species (28.12%), followed by Trichophyton mentagrophyte. (T. mentagrophyte) (25.0%) Trichophyton soudanense (T. soundanense), which is a rare species (not reported from any studies) was isolated from cases of T. corporis and T. cruris.

Frequency of dermatophytes in the metropolitan area of Porto Alegre, RS, Brazil

A prevalência de dermatofitos na regiao metropolitana de Porto Alegre (RS), foi analisada de modo retrospectivo durante o periodo de junho de 1981 a junho de 1995. As espécies de dermatofitos foram isoladas de amostras de pele, pelos e unhas, em duas instituiçöes de Porto Alegre : Serviço de Micologia de Instituto de Pesquisas Biológicas Jandyr Maya Faillace, da Secretaria de Saúde e Meio Ambiente do Rio Grande do Sul, que atende predominantemente as classes sociais B e C e Laboratorio Weinmann, que atende predominantemente as classes sociais A e B. Observou-se o predominio do dermatofito Trichophyton rubrum (55,33 por cento) seguido pelo Trichophyton mentagrophytes (21,46 por cento). Os dados coletados foram comparados com a prevalência observada no interior do estado num período de 32 anos (1960-1992). Os fungos Trichophyton verrucosum, Trycophyton simii, Microsporum persicolor, Trichophyton schoenleinii, Microsporum nanum e Microsporum cookei isolados no interior do estado näo foram observados na capital. Trichophyton violaceum, isolado na capital näo foi encontrado no interior

A focus of favus due to Trichophyton schoenleinii in Rio Grande do Sul, Brasil

E relatada a ocorrencia de um foco de favo por Trychophyton schoenleinii afetando sete pessoas de uma familia, 29 anos apos o ultimo registro da doenca no Rio Grande do Sul

Frecuencia de dermatofitos en pacientes hospitalizados / Frequency of dermatophytes in hospitalized patients

Las dermatofitosis (invasión de pelo, piel y/o uñas por dermatofitos) tienen una frecuencia de 7,5-61 por ciento en la población general, la más frecuente es la tiña pedis o pie de atleta. La condición de portador de dermatofitos en pacientes hospitalizados puede constituir una fuente potencial de infección para los pacientes y personal que comparten utensilios y baños. Para determinar la frecuencia de dermatofitos en hospitalizados, se estudiaron 66 pacientes ingresados al Servicio de Medicina, Hospital del Salvador entre julio y septiembre de 1991. Se tomaron muestras por raspado, del tercero y cuarto espacio interortejo de los pies, efectuando examen directo con KOH al 20 por ciento y cultivo en agar Sabouraud glucosado al 2 por ciento y agar Lactritmel. En 7 pacientes (10,6 por ciento), se detectó una dermatofitosis y 5 eran portadores sanos (7,6 por ciento). Los dermatofitos aislados fueron: trichophyton rubrum, trichophyton mentagrophytes. Del total de pacientes, 23 tenían como base patologías metabólicas o neoplásicas y en ellos la frecuencia de dermatofitos fue más elevada (30,4 por ciento). Estos resultados sugieren que la dermatofitosis podría constituir una infección intrahospitalaria y que es necesario estudiar la infección por dermatofitos y reforzar las medidas profilácticas (aseo de baños, pisos, uso individual de elementos de aseo personal) para evitar su transmisión en pacientes hospitalizados

First case of human infection by Trichophyton vanbreuseghemii in Brazil

E relatado o primeiro caso de infeccao humana por Trichophyton vanbreuseghemii no Brasil.