Dos interesantes contaminantes fúngicos filamentosos en muestras clínicas positivas a Trychophyton rubrum: una situación de curiosidad morfológica / Two interesting filamentous fungal contaminants in clinical samples positive to Trychophyton rubrum: a situation of morphological curiosity

Las dermatofitosis corresponden a un grupo de enfermedades micóticas comunes en piel y fanéreas, donde Trichophyton rubrum es el agente causante más frecuente a nivel mundial y presente en nuestros 2 casos de pacientes masculinos con estas micosis, una en uñas y la otra en piel. Sin embargo, el enfoque de esta publicación se basa principalmente en la presencia de 2 interesantes contaminantes (uno en cada caso clínico) presentes solo en los cultivos de las primeras siembras como saprófitos y por ende como propágulos de dispersión, asociados al ambiente y sin intervención clínica demostrada en ambas micosis. La descripción morfofisiológica de estos 2 contaminantes Metarhizium purpureo-genum(similis) y Monascus ruber fue más bien una curiosidad esencial que el micólogo clínico adquiere en su contínua formación y ante la posibilidad de infecciones mixtas, pudiendo conjugar sus hallazgos junto al análisis taxonómico y los factores geográficos y edáficos asociados a su distribución. (AU)

Dermatophytoses belongs to a group of common mycotic diseases in skin and pharynals, where Trichophyton rubrum is the most frequent causative agent worldwide and present in our 2 cases of male patients with these mycoses, one in nails and the other in skin. However, the focus of this publication is mainly about the presence of 2 interesting contaminants (one in each clinical case) present only in the crops of the first sowings as saprophytes and therefore as dispersal propagules, associated with the environment and without clinical intervention demonstrated in both mycoses. The morphophysiological description of these 2 contaminants, Metarhizium purpureogenum (similis) and Monascus ruber was rather an essential curiosity that the clinical mycologist acquires in his continuous training and in the face of the possibility of mixed infections, being able to combine his findings together with the taxonomic analysis and the geographic and edaphic factors associated with its distribution. (AU)

Dermatoscopic fi ndings as a complementary tool in the differential diagnosis of the etiological agent of tinea capitis

Tinea capitis is a scalp infection caused by fungi. In Brazil, the main causative agents are Microsporum canis and the Trichophyton tonsurans. Etiological diagnosis is based on suggestive clinical findings and confirmation depends on the fungus growth in culture. However, it is not always possible to perform this test due to lack of availability. We reveal the dermoscopic findings that enable distinction between the main causative agents of Tinea capitis, M. canis and T. tonsurans. The association of clinical and dermatoscopic findings in suspected Tinea capitis cases may help with the differential diagnosis of the etiological agent, making feasible the precocious, specific treatment.

Laser irradiation on growth of trichophyton rubrum: an in vitro study

Trichophyton rubrum is one of the most common species of dermatophytes which affects superficial keratinous tissue. It is not especially virulent but it can be responsible for considerable morbidity. Although there are different therapeutic modalities to treat fungal infections, clinicians are searching for alternative treatment because of the various side effects of the present therapeutic methods. As a new procedure, Laser therapy has brought on many advantages in clinical management of dermatophytes. Possible inhibitory potential of laser irradiation on fungal colonies was investigated invitro in this study. A total of 240 fungal plates of standard size of trichophyton rubrum colonies that had been cultured from the lesions of different patients at the mycology laboratory, were selected. Each fungal plate was assigned as control or experimental group. Experimental plates were irradiated by a laser system [low power laser or different wavelength of high power laser]. The effects of different laser wavelengths and energies on isolated colonies were assessed. After laser irradiation, final size of colonies was measured on the first, the 7[th] and the 14[th] day after laser irradiation. Although low power laser irradiation did not have any inhibitory effect on fungal growth, the Q-Switched Neodymium-Doped Yttrium Aluminium Garnet [Nd:YAG] laser 532nm at 8j/cm[2], Q-Switched Nd:YAG laser 1064nm at 4j/cm[2] to 8j/cm[2] and Pulsed dye laser 595nm at 8j/cm[2] to 14j/cm[2] significantly inhibited growth of trichophyton rubrum in vitro. Q-Switched Nd:YAG 532nm at 8j/cm[2], Q-Switched Nd:YAG laser 1064nm at 4j/cm[2] to 8j/cm[2] and pulsed dye laser [PDL] 595nm at 8j/cm[2] to 14j/cm[2] can be effective to suppress trichophyton rubrum growth

Aislamiento de Sporothrix pallida y Trichophyton rubrum en onicomicosis de mano / Isolation of Sporothrix pallida and Trichophyton rubrum in hand onychomycosis

Se presenta un caso de onicomicosis de mano, de la cual se aisló en repetidas ocasiones Sporothrix pallida y Trichophyton rubrum. Se discute sobre los principales agentes de onicomicosis, el rol de los hon- gos ambientales y del aislamiento de S.pallida en este y en otro tipo de muestras.

It reports a case of hand onychomycosis, which was isolated repeatedly Sporothrix pallida and Trichophyton rubrum. We discuss the main agents of onychomycosis, the role of the environmental fungi and S.pallida isolation in this and other samples.

Onicomicosis: epidemiología, agentes causales y evaluación de los métodos diagnósticos de laboratorio / Onychomycoses: epidemiology, causative agents and assessment of diagnostic laboratory methods

Desde marzo de 2007 hasta marzo de 2011 se estudiaron prospectivamente 414 pacientes con onicodistrofias en un laboratorio privado de Esquel. La prevalencia de onicomicosis de pie fue del 78 %; la de mano, del 58 %. Los principales agentes etiológicos fueron Trichophyton rubrum, Candida spp. y Trichophyton mentagrophytes. El desarrollo de dermatofitos prevaleció en las onicopatías de pie y el de Candida spp. en las de uñas de mano (ambos, p < 0,05). En las onicomicosis candidiásicas predominaron especies diferentes a Candida albicans. Las onicomicosis fueron más frecuentes en los hombres que en las mujeres. A su vez, en los hombres hubo más aislamientos de T. rubrum en pies (p < 0,05) y mayor proporción de exámenes directos (ED) y cultivos positivos (ambos, p < 0,05). La correlación entre los resultados del ED y del cultivo fue del 68 %. El rédito de ambos métodos se asoció a un mayor tamaño de la lesión ungueal. El ED fue más efectivo en onicodistrofias que superaban los 5 años de evolución. La positividad del cultivo fue independiente de la cronicidad de la onicodistrofia.

Since March 2007 to March 2011, 414 patients with onychopathies were prospectively analyzed. Prevalence of the toenail and fingernail mycoses was 78 % and 58 %, respectively. The major etiological agents were Trichophyton rubrum, Candida spp. and Trichophyton mentagrophytes. Dermatophytes were more frequently cultured from toenails, whereas Candida spp. from fingernails (both, p < 0.05). In candidal onychomycosis, species different from C. albicans were prevalent. A higher prevalence of toenail and fingernail mycoses, a predominance of T. rubrum in toenails (p < 0.05), and greater positivity in the direct examination (DE) and in culture (both, p < 0.05) were more frequently observed in men than in women. The correlation between DE and culture was 68 %. DE and culture yields were associated with a greater size lesion. DE was more effective in onycodystrophies with duration of more than 5 years. Culture positivity was independent of nail affection chronicity.

Isolation, characterization and antifungal activity of Streptomyces sampsonii GS 1322.

For new antifungal antibiotics from actinomycetes, a strain of Streptomyces GS 1322 was isolated from a sample of garden soil. The strain was found to possess antagonistic activity against four fungi i.e., Candida albicans, Aspergillus niger, Microsporum gypseum and Trichophyton sp. The strain was identified as Streptomyces sampsonii and the antifungal compound produced by it was found to be the heptaene group of polyene antibiotics.

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.

Trichophyton violaceum: a rare isolate in 18-day-old neonate.

Trichophyton violaceum, a less common and geographically restricted infection is reported in a 18-day-old neonate. The diagnosis was made by potassium hydroxide of skin scraping examination and confirmed by culture. The patient was treated successfully with miconazole nitrate application. A large family with crowded living was considered the main predisposing factor.

Differntiation of trichophyton rubrum, trichophyton mentagrophytes and trichophyton tonsurans using defined media

The aim of the study was to differentiate between Trichophyton species using different media. A total of 60 strains of Trichophyton rubrum [21], T. mentagrophytes [24], and T. tonsurans [15], were inoculated onto 4 culture media. Bromocresol-purple milk solid glucose medium [BCP-MS-G] and a solid minimal basal medium containing either / or 5% Sorbitol, 1% Acetate and 10% Sodium chloride [NaCl]. All plates were examined after 7 days incubation at 25°C. Within 7 days, 20 [95%] strains of T.rubrum and 15[100%] strains of T. tonsurans were found to have negative alkaline reaction on BCP-MS-G medium, and inhibited by 20% NaCl medium. By comparison, 17 [80%] strains of T. rubrum exhibited heavy growth on sorbitol, whereas 18 [85%] strains had no growth on acetate medium. None of the 4 media above was independently able to differentiate between Trichophyton species but in combination they were able to do so without significant decrease in reliability

Piedra blanca genital: a propósito de un caso / Genital white piedra: case report

Se presenta un paciente de sexo masculino, de 19 años, que consultó por descamación plantar e intertrigo inguinal. Al examen clínico se comprobó además nódulos blancos en el vello pubiano. El examen directo de esos pelos demostró artrosporos y elementos levaduriformes. En el cultivo creció Trichosporon beigelii. Se efectuó microscopía electrónica de barrido. Los exámenes micológicos diagnosticaron una dermatoficia plantar y eritrasma a nivel inguinal. El tratamiento consistió en depilación de la zona pubiana y griseofulvina oral para la dermatofitosis. Se logró la remisión completa y no se registraron recidivas