Analysis of pathogenic fungi causing tinea capitis: a single-center retrospective study / 中华皮肤科杂志

Objective:To investigate the distribution of pathogenic fungi in patients with tinea capitis diagnosed in Xijing Hospital, Air Force Medical University in the past 10 years.Methods:A total of 871 outpatients or inpatients with tinea capitis were collected from the Department of Dermatology, Xijing Hospital from January 2011 to December 2020, and their clinical data and pathogen distribution were retrospectively analyzed. Pearson chi-square test was used to analyze differences in the pathogen distribution between children and adult patients with tinea capitis.Results:Of 871 patients with tinea capitis, 588 (67.5%) were males and 283 (33.5%) were females; 21 (2.40%) were aged less than 1 year, 266 (30.50%) aged 1 - 3 years, 352 (40.40%) aged 4 - 6 years, 187 (21.50%) aged 7 - 12 years, 4 (0.50%) aged 12 - 18 years, and 41 (4.70%) were aged 18 - 74 years. A total of 705 pathogenic strains were isolated from these patients, including 599 strains of Microsporum canis (85.0%) , 52 strains of Trichophyton mentagrophytes complex (7.4%) , 27 strains of Trichophyton tonsurans (3.8%) , and 18 strains of Trichophyton violaceum (2.6%) . Among the pathogenic fungi of tinea capitis, the proportion of Trichophyton violaceum was significantly higher in adults (8.8%) than in children (2.2%, P = 0.048) . Conclusions:In the past 10 years, the patients with tinea capitis in the Department of Dermatology, Xijing Hospital were mainly children aged 1 - 6 yearswhile adults, and adult patients with tinea capitis were uncommon. The main pathogen of tinea capitis was Microsporum canis, followed by Trichophyton mentagrophytes complex.

Analysis of Adult Patients with Tinea Capitis in Southeastern Korea

BACKGROUND: Tinea capitis is a cutaneous infection of dermatophytes and predominant in children. Although tinea capitis in Korea is controlled by oral antifungal medications and concerted public health initiatives, it's still a health issue.OBJECTIVE: To investigate changes in the epidemiological and mycological characteristics of adult patients with tinea capitis in southeastern Korea.METHODS: Using medical records from Kyungpook National University Hospital and Catholic Skin Clinic from 1989 to 2018, we retrospectively investigated the epidemiological and mycological characteristics of 266 adult patients (aged over 20) with tinea capitis.RESULTS: Among total 266 patients, 239 were KOH-positive. The annual incidence of tinea capitis ranged from 3 to 18 between 1989 and 2018. Of the total, 54 (20.30%) were male and 212 (79.70%) were female. Eighty patients (30.08%) were in their seventies, the most commonly affected age group. Of the remaining, 58 (21.80%) were in their sixties, and 41 (15.41%) in eighties. Among all, 77 (28.95%) visited the hospital in summer, 72 (27.07%) in spring, 64 (24.06%) in winter, and 53 (19.92%) in fall. Dermatophytes were cultured from 171 patients. Microsporum canis was the most common dermatophyte (42.48%), while Trichophyton rubrum was the second (15.79%). Of the 266 patients, 186 (69.92%) lived in urban areas and 80 (30.08%) in rural areas.CONCLUSION: The epidemiological and mycological characteristics of adult patients with tinea capitis were different from those of children in terms of annual incidence, sex distribution, and isolated dermatophytes. These results provide useful information for the treatment and prevention of tinea capitis.

Analysis of pathogenic dermatophytes from patients with tinea capitis in a hospital in Hangzhou / 中华皮肤科杂志

Objective To analysis changes in species distribution of pathogenic dermatophytes from patients with tinea capitis in the Hangzhou Third Hospital between 2015 and 2017.Methods Demographic and mycological data were collected from 321 patients with confirmed tinea capitis in the Hangzhou Third Hospital between 2015 and 2017,and analyzed retrospectively.Results Of the 321 patients with tinea capitis,180 were males,and 141 were females.Their age of onset ranged from 1 month to 70 years.There were 154 (47.9％) preschool children and 13 (4.0％) adults.A total of 321 fungal strains were isolated,including 159 (49.5％) strains of Microsporum canis,110 (34.3％) strains of Trichophyton mentagrophytes,38 (11.8％) strains of Trichophyton violaceum,8 (2.5％) strains of Trichophyton tonsurans,4 (1.2％) strains of Microsporum gypseum,and 2 (0.6％) strains of Trichophyton rubrum.There was no significant difference in the distribution of fungal species (x2 =9.09,P ＞ 0.05) or the proportion of anthropophilic and non-anthropophilic dermatophytes among different age groups (x2 =1.85,P ＞ 0.05).The proportion of non-anthropophilic dermatophytes significantly differed among 2015,2016 and 2017 (x2 =23.82,P ＜ 0.01).From 2015 to 2017,the proportions of Microsporum canis were 32.5％,47.6％ and 59.6％ respectively,and the proportions of Trichophyton mentagrophytes were 53.0％,35.4％ and 23.7％ respectively.Conclusions During 2015-2017,the main population with tinea capitis in Hangzhou Third Hospital was preschool children.Moreover,the main pathogenic dermatophyte was Microsporum canis,whose proportion gradually increased year by year,followed by Trichophyton mentagrophytes,whose proportion gradually decreased year by year.

Localization of PQ-LRP protein in Microsporum canis / 中华皮肤科杂志

Objective To determine the location of PQ-LRP protein in Microsporum canis using the enhanced green fluorescent protein(EGFP)as a marker.Methods The total RNA was extracted from Microsporum canis,and reversely transcribed into cDNA.The PQ-LRP gene was amplified by PCR using the above cDNA as the template.The fusion gene of PQ-LRP gene and EGFP gene was linked to the plasmid pCAMBIA 1300.Microsporum canis was subjected to Agrobacterium tumefaciens-mediated transformation,in order to achieve the integrated expression of the fusion gene LRP-EGFP in Microsporum canis under the regulation by the fungal universal promoter Ptrpc and terminator Ttrpc.Laser-scanning confocal microscopy was conducted to determine the cellular localization of the fusion protein.Results The expression vector pCAMBIA-LRP-EGFP was successfully constructed,and the fusion gene LRP-EGFP was expressed integratedly in Microsporum canis.Laser-scanning confocal microscopy showed that fluorescence signals of LRP-EGFP were concentrated on the cell membrane of Microsporum canis,giving a granular or cluster-like appearance.Conclusion The infusion gene LRP-EGFP can be successfully expressed in Microsporum canis,and PQ-LRP protein is located on the cell membrane of Microsporum canis.

Isolamento e perfil enzimático de cães e gatos com dermatofitose atendidos em hospitais veterinários do Recife, Pernambuco / Isolation and enzymatic profile of dogs and cats with dermatofitosis attended at veterinary hospitals in Recife, Pernambuco, Brazil

Os dermatófitos são fungos que podem causar infecções superficiais da pele, cabelo e unhas em humanos e animais. As espécies de dermatófitos mais frequentemente isoladas dos cães e gatos afetados por micoses são Microsporum gypseum e principalmente Microsporum canis. O papel crucial durante o processo de infecção é a produção de enzimas extracelulares essenciais para a invasão e estabelecimento do agente patogênico no tecido do hospedeiro. O objetivo deste trabalho foi isolar dermatófitos de cães e gatos e avaliar o perfil enzimático dos isolados obtidos. Amostras de pelos e escamas epidérmicas foram coletadas de cães e gatos em instalações veterinárias em Recife/PE, e os isolados foram identificados com base nas características macroscópicas e microscópicas. A análise qualitativa das enzimas urease, protease, lipase, colagenase e fosfolipase foi avaliada a partir dos dermatófitos isolados. Durante 10 meses, um total de 106 animais, que compreendeu de 99 cães e sete gatos com sinais clínicos, independentemente do sexo e raça foram avaliados. Apenas oito animais foram confirmados com dermatofitose, principalmente cães (n=7), sendo seis afetados por M. canis e um por M. gypseum, a raça mais afetada foi Yorkshire (n=3). No entanto, apenas um gato foi confirmado com M. canis. Não foi observada predisposição relacionada ao sexo quanto à ocorrência de dermatofitose nos cães e gatos avaliados. Os dermatófitos isolados apresentaram perfis semelhantes para as enzimas urease, lipase, protease, fosfolipase e colagenase, característica importante em infecções patogênicas. O diagnóstico clínico destas zoonoses com base na confirmação microbiológica e uma compreensão dos mecanismos subjacentes é de grande importância para o tratamento e prevenção de doenças fúngicas em animais.(AU)

Dermatophytes are fungi that can cause superficial infections of the skin, hair and nails in man and animals. The most frequent dermatophyte species isolated from dogs and cats are Microsporum gypseum, most notably Microsporum canis. The crucial role during the infection process is the production of extracellular enzymes essential for the invasion and establishment of the pathogen in the host tissue. The objective of this research was to isolate dermatophytes from dogs and cats and evaluate the enzymatic profile of the isolates obtained. Hair samples and epidermal scales were collected from dogs and cats in veterinary facilities in Recife-PE, and the isolates were identified based on macroscopic and microscopic characteristics. The qualitative analysis of the enzymes urease, protease, lipase, collagenase and phospholipase was evaluated from the isolated dermatophytes. During 10 months, a total of 106 animals, comprising of 99 dogs and seven cats with clinical signs, regardless of sex and race were evaluated. Only eight animals were confirmed with dermatophytosis, mostly dogs (n=7), being six affected by M. canis and one by M. gypseum, the race most affected was Yorkshire (n=3). However, only one cat was confirmed with M. canis. No sex-related predisposition was observed regarding the occurrence of dermatophytosis in dogs and cats evaluated. Isolated dermatophytes showed similar profiles for the enzymes urease, lipase, protease, phospholipase and collagenase, important characteristic for pathogenic infections. The diagnosis of this zoonosis based on microbiological confirmation and a better understanding of the underlying mechanisms is of great importance for the treatment and prevention of fungal diseases in animals.(AU)

Tinea Capitis Caused by Microsporum canis after Visiting a Pet Café in a Sibling / 대한피부과학회지

No abstract available.

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

BACKGROUND: Tinea capitis remains a prevalent health problem among school-aged children. OBJECTIVE: To estimate the prevalence of tinea capitis among primary school students, in Fayoum, Egypt with identification of etiological agents in both public and private primary schools. METHODS: A cross-sectional study was conducted in twelve primary schools. The students were selected from different grades with a total number of 12,128 students. Hair and scalp were clinically examined for any lesions that may suspect tinea capitis and mycological samples were collected for direct microscopy and culture. RESULTS: The prevalence of tinea capitis in the study group was 0.4% and higher in public than private schools (73.5% versus 26.5% respectively). Boys were more affected than girls with boy to girls' ratio 5:1. Intrafamily history of infection was present in 40.8% of tested group while 51% showed low social standard profile. Mycological culture revealed that Microsporum canis was the predominant isolated organism followed by M. audouinii (52% and 36% respectively). CONCLUSION: M. canis is replacing Trichophyton violaceum as an etiology for tinea capitis in Egypt with lower prevalence rate than reported previously.

Microscopic Findings of Macroconidia in Microsporum canis / 대한의진균학회지

No abstract available.

Tinea Capitis Caused by Microsporum canis Misdiagnosed as Seborrheic Dermatitis in a 79-Year-Old Woman / 대한의진균학회지

Microspoum canis is a zoophilic dermatophyte that is often transmitted to humans from cats and dogs. It has become one of the most important causative agents in tinea capitis ane kerion celsi. Tinea capitis is uncommon in an adult. Moreover, tinea capitis caused by Microspoum canis is rare in an elderly. The location of the lesion and the clinical course of tinea capitis might have led physicians into misdiagnosis as the seborrheic dermatitis. Therefore, we report this case to emphasize the importance of KOH mount and fungal culture of the skin lesions mimicking seborrheic dermatitis. We report a case of tinea capitis caused by Microspoum canis in a 79-year-old woman. The lesions were manifested by fine scaly erythematous patches on the fronto-vertex scalp for 2 weeks. She was diagnosed as seborrheic dermatitis in local clinic and was treated with topical steroid. However, the lesion was not improved. She kept a cat as a pet. Culture from biopsy specimen on Sabouraud's dextrose agar showed typical cottony colonies of Microspoum canis. The nucleotide sequence of internal transcribed spacer for clinical isolate was identical to that of Arthroderma otae strain ATCC 23828 (GenBank accession number AY213657). She was treated with 200 mg of oral itraconazole daily for 12 weeks. The skin lesions improved after treatment, and recurrence has not been observed.

A Case of Kerion Celsi Misdiagnosed as Ruptured Epidermal Cyst / 대한의진균학회지

Kerion celsi is an inflammatory infection, caused by a vigorous T-cell mediated host response to the dermatophyte infection. In the case of severe inflammation, it can be misdiagnosed as other disease like cellulitis, impetigo, furuncle and epidermal cyst. Microsporum(M.) canis is most likely transmitted by contact of animal hosts such as cats and dogs with humans. We report the 75-year-old female who presented two months history of tender erythematous scaly plaques with pustules, crusts on right scalp area. At first, from the histopathologic findings of the lesion, the patient was diagnosed epidermal cyst because of cyst-like structure in mid-dermis. But the fungal culture revealed M. canis as the causative fungus. Herein we report a educational case of kerion celsi mistaken for ruptured epidermal cyst.

A Case of Multiple Tinea Infections in an Infant Child After Contact with a Dog / 대한의진균학회지

Dermatophytosis in children is relatively infrequent than adults. Dermatophytosis in children can be different clinically and mycologically from those in adults in that children experience rapid physical changes and they have different skin features and environments from those of adults. Microsoprum (M.) canis is one of the zoophilic dermatophytes responsible for 3~30% of tinea corporis and tinea capitis in children. It is most likely transmitted by contact with infected animals such as cats and dogs. Clinical manifestations were single or multiple annular shaped, erythematous scaly patches and sometimes hard to differentiate with other skin diseases. A 6-year-old girl presented with multiple, pruritic, erythematous scaly patches on cheek and buttock. The lesion started 3 weeks before visiting our skin clinic. There was no personal or family history of any skin disease but she had a history of contacting with a dog. A fungal culture from tissue of the lesions grown on potato dextrose agar-corn meal-tween 80 showed typical Microsporum canis. The skin lesions were clinically improved after topical treatment for 4 weeks.

Antifungal activity of plant extracts against microsporum canis and candida spp. strains / Actividad antifúngica de extractos de plantas contra cepas de microsporum canis y candida spp

Aiming to find a phytotherapeutic compounds to treat animal fungal infections, plants commonly found in Northeastern Brazil were evaluated in vitro against Microsporum canis and Candida spp. strains isolated from dogs and cats. The leaf ethanol extracts of Momordica charantia, Calotropis procera, Peschiera affinis and Piper tuberculatum and decoction of Mangifera indica were initially evaluated by the agar-well diffusion method. Four extracts induced growth inhibition zones against M. canis: P. tuberculatum (20 mm), M. indica (14 mm), M. charantia (13 mm) and P. affinis (11 mm). None of them were active against Candida spp. Broth microdilution tests were performed for M. canis strains (n=5), to find the minimum inhibitory concentration (MIC) and the minimum fungicidal concentration (MFC). The geometric means for the MIC values were 590, 370, 350, 170 ug/mL, and for the MFC values were 1190, 750, 700, 340 ug/mL for M. charantia, P. affinis, P. tuberculatum and M. indica, respectively. Therefore, extracts from M. charantia, P. affinis, P. tuberculatum and M. indica are good candidates to produce antifungal phytotherapics since these extracts demonstrated good activity against M. canis.

Con el objetivo de encontrar compuestos fitoterapéuticos para tratar las infecciones por hongos de los animales, plantas que se encuentran comúnmente en el noreste de Brasil se evaluaron in vitro frente a cepas de Microsporum canis y Candida spp. aisladas de perros y gatos. Los extractos etanólicos de hojas de Momordica charantia, Calotropis procera, Peschiera affinis y Piper tuberculatum y la decocción de Mangifera índica fueron evaluados inicialmente por el método de difusión en pocillos de agar. Cuatro extractos indujeron zonas de inhibición del crecimiento contra M. canis: P. tuberculatum (20 mm), M. índica (14 mm), M. charantia (13 mm) y P. affinis (11 mm). Ninguno de ellos fue activo contra Candida spp. Se realizaron pruebas de microdilución en caldo para las cepas de M. canis (n = 5), para encontrar la concentración mínima inhibitoria (CIM) y la concentración fungicida mínima (CFM). Las medias geométricas de los valores de CIM fueron 590, 370, 350, 170 mg/ml, y para los valores de CFM fueron 1.190, 750, 700, 340 mg/ml de M. charantia, P. affinis, P. tuberculatum y M. indica, respectivamente. Por lo tanto, los extractos de M. charantia, P. affinis, P. tuberculatum y M. indica son buenos candidatos para la producción de fitoterápicos antifúngicos ya que estos extractos demostraron una buena actividad contra M. canis.

A Case of Majocchi Granuloma Caused by Microsporum canis Presented as Tinea Incognito / 대한피부과학회지

No abstract available.

Mating Type Analysis of Dermatophytes using Mating Type Gene / 대한의진균학회지

BACKGROUND: Traditionally, mating types of dermatophytes had been identified by mating experiments. It took a long time and there were many limitations. Recently, we can figure out the fungal mating types using molecular mating type analysis by detecting mating type (MAT) genes. The mating type (+) specific gene of the high-mobility-group (HMG) DNA binding domain and the mating type (-) specific gene of alpha-box were found in Arthroderma simii and A. vanbreuseghemii. OBJECTIVE: We applied this molecular mating type analysis to strains of Trichophyton interdigitale, T. rubrum, Microsporum canis in Korea and compared these results with previous reports. METHODS: Thirty-four strains of T. interdigitale (12 granular types, 9 powdery types, 8 purple-red types, 5 cottony types), 5 strains of T. rubrum, and 5 strains of M. canis were examined. We analyzed ribosomal RNA internal transcribed space 1, 4 sequencing of T. interdigitale subtypes and investigated the mating type of dermatophytes using alpha-box gene and HMG gene primers. RESULTS: Among 12 strains of granular type of T. interdigitale, 9 strains were type (-) and other 3 strains were type (+). All of them were zoophilic. All strains of powdery, purple-red and cottony types of T. interdigitale were type (+) and anthropophilic. In T. rubrum and M. canis, all strains were type (-). These results were matched with previously reported studies. CONCLUSION: The molecular mating type analysis of dermatophytes was quicker method than conventional mating experiments. Moreover, MAT genes are highly conserved even in apparently asexual fungi. The results were well matched with previous reports with traditional mating tests.

A Retrospective Review Of Tinea Capitis Infection

Background: Tinea capitis (TC), a fungal infection of the scalp, hair follicles and hair shafts, is common among the paediatric population especially under tropical conditions1. The etiological factors vary between different regions of the world. Clinical presentation of tinea capitis varies widely from non-inflammatory to severe, painful inflammatory lesions. Aim: To look into the clinical manifestations, causative agents and the treatment pattern for tinea capitis in Penang Hospital. Methods: A retrospective study of all patients who were treated clinically for tinea capitis in Penang Hospital from January 2011 to June 2013. Results: There were a total of thirty nine patients treated for tinea capitis during this period. Tinea capitis was found to be most common in the 7-12 year age group (44%) with a male to female ratio of 2:1. Non-inflammatory type (54%) was more common then the inflammatory type. Twenty seven of them (69%) had positive fungal culture of their pluck hair roots. The most common dermatophyte detected was Microsporum canis (92%) followed by Trichophyton rubrum (4%) and Trichophyton metagraphyte (4%). Thirty-one (80%) of them were treated with griseofulvin at a dose of 10-15mg / kg /day. The rest were treated with itraconazole, terbinafine or fluconazole. All of them responded well to the treatment. In this cohort only one patient, has a second episode of infection a year later. He is a child who was concomitantly undergoing chemotherapy for acute lymphoblastic leukaemia. Conclusion: Tinea capitis is predominantly an infection of pre-adolescent children and M. canis was the most common dermatophyte isolated.

PQ-loop repeat protein gene silencing by RNA interference in Microsporum canis / 中华皮肤科杂志

Objective To build a RNA interference vector for PQ-loop repeat protein (LRP) gene,and to evaluate the effect of the vector on the expression of PQ-LRP gene in Microsporum canis.Methods The PUC-PLULT and PCB309-PLULT vectors were constructed sequentially by using Agrobacterium tumefaciens-mediated T-DNA insertional mutagenesis,adding multiple cloning sites,and introducing the hygromycin-resistance gene.Microsporum canis was transformed with the PCB309-PLULT vector followed by a series of passages and hygromycin selection.Real-time quantitative PCR was performed to measure the expression of PQ-LRP gene in Microsporum canis before and after transformation.Results The intermediate vectors PUC-PLUT and PUC-PLULT were constructed and identified by PCR and gene sequencing.The 8 825-bp interference vector PCB309-PLULT was successfully built and confirmed by enzyme digestion.The optimum concentration of hygromycin for screening for Microsporum canis transformants was determined as 300 mg/L.The mRNA expression level of PQ-LRP was decreased by 61％ in the transformants as compared with untransformed Microsporum canis (0.39 vs.1.00).Conclusion The constructed PCB309-PLULT interference vector can effectively inhibit the expression of PQ-LRP gene in Microsporum canis.

Simultaneous Occurrence of Tinea corporis Caused by Microsporum canis in a Grandmother and a Granddaughter / 대한의진균학회지

Microsporum (M.) canis is one of the zoophilic dermatophytes which can cause ringworm in cats and dogs and is responsible for 3~30% of tinea corporis and tinea capitis in human. It is most likely transmitted by contact with infected animals, but rare cases of person-to-person transmission and an outbreak among school girls have also been reported. Herein we report on interesting cases of tinea corporis caused by M. canis in a grandmother and a granddaughter. A 63-year-old woman presented with pruritic, scaly, erythematous plaques on the post. neck and trunk which had started 2 months ago. Also her 9-year-old granddaughter presented with pruritic, annular, erythematous plaques on chest and back for 7 days. They denied contact with animals. KOH smear showed several hyphaes on microscope. Fungus culture on potato dextrose agar showed growth of colonies with whitish fluffy surface and radial folds, the dorsal surface of the colonies showed golden-brown color which were identified as M. canis in both patients. As for the grandmother the lesions improved with oral itraconazole 200 mg/day for 7 days and topical antifungal cream for 5 weeks which resulted in marked improvement of the lesions.

Clinical Study of Dermatophytosis Caused by Microsporum canis / 대한의진균학회지

BACKGROUND: Microsporum (M.) canis is a zoophilic dermatophyte commonly acquired from cats or dogs, and it is the most common pathogen of tinea capitis in Korea. An increase in the incidence of M. canis infection has been observed after 1970s. OBJECTIVE: To investigate the changes in epidemiological features and clinical findings on M. canis infection. METHODS: We retrospectively carried out an analysis of 133 patients with M. canis infection among clinically suspected dermatophytosis during last 10 years, from 2001 to 2010. RESULTS: The isolation rate of M. canis was 5.9% of all isolated dermatophytes. The annual number of patients infected by M. canis has fluctuated between 8 and 22 and was highest in 2007. The infections were most prevalent in patients under the age of 10 years (51.1%). The ratio of male to female patients was 0.8:1 in total, but 1.1:1 in children under the age of 10 years, and 0.4:1 in adults. Seasonally, 58.6% (78 cases) occurred in winter and spring, which was more prevalent than in other seasons. The highest clinical type among dermatophytosis was tinea capitis (56.4%), and followed by tinea faciale (15.8%), and tinea corporis (15.0%). The incidence of patients with the noninflammatory lesions (68.3%) in tinea capitis was higher than inflammatory lesions (31.7%) in clinical characteristics. CONCLUSION: We analyzed the patients with dermatophytosis caused by M. canis during last 10 years, from 2001 to 2010, and their prevalence, seasonal changes, and clinical charateristics were demonstrated and compared with previous studies.

Actividad antifúngica in vitro y concentración mínima inhibitoria mediante microdilución de ocho plantas medicinales / In vitro antifungal activity and minimum inhibitory concentration by microdilution of eight medicinal plants

Se determinó la actividad antifúngica in vitro de los extractos metanólicos, etanólicos e hidroalcohólicos de Hypericum laricifolium (partes aéreas), Ilex guayusa Loes (hojas), Juglans neotropica Diels (corteza), Piper lineatum (hojas), Piper spp. (hojas), Psidium guajava (hojas), Cassia reticulata Wild (planta entera) y Terminalia catappa (hojas); recolectadas en los departamentos de Amazonas y Cajamarca. La actividad antifúngica se evaluó mediante el método de difusión en agar frente a Candida albicans ATCC 10231, Aspergillus niger ATCC 16404 y Microsporum canis cepa clínica y la Concentración Mínima Inhibitoria (CMI) por el método de microdilución colorimétrico, utilizando como controles ketoconazol y fluconazol. Todos los extractos presentaron actividad antifúngica importante frente a C. albicans y M. canis, y ninguno tuvo actividad frente a A. niger. Las condiciones de laboratorio para determinar la concentración mínima inhibitoria (CMI) de C. albicans mediante el método de microdilución colorimétrico fueron: temperatura de incubación de 37°C, tiempo de incubación de 24 h, inóculo final 0,5-2,5 x 103 ufc/mL y 0,05 mg de resazurina por pozo; y, para M. canis fueron temperatura de incubación de 37°C, tiempo de incubación de 4 días, inóculo final de 1,2 ­ 6 x 104 ufc/mL y 0,05 mg de resazurina por pozo. Mediante microdilución se determinó que 19 (79%), 18 (75%) y 24 (100 %) de los extractos investigados presentaron CMIs ≤ 1000 µg/mL, frente a Candida albicans ATCC 10231, Candida albicans cepa clínica y Microsporum canis, respectivamente. Los extractos con la mayor actividad antifúngica fueron los de Juglans neotropica Diels, Psidium guajava y Terminalia catappa; con CMIs < 100 µg/mL. El método de microdilución colorimétrico usando resazurina demostró ser útil para el screening antifúngico de extractos de plantas.

Perfil de susceptibilidad in vitro de aislados clínicos de microsporum canis a los antifungicos griseofulvina, itraconazol, voriconazol, terbinafina y anfotericina B / In vitro susceptibility profile of clinical isolates of microsporum canis to the antifungals griseofulvin, itraconazole, voriconazole, terbinafine and amphotericin B

Las dermatofitosis son las micosis superficiales más frecuentes en el humano y son causados por hongos de los géneros: Trichophyton Microsporum y Epidermophyton. En Venezuela son el principal motivo de consulta dermatológica, constituyendo un verdadero problema de salud pública por su alta morbilidad. El objetivo del estudio fue conocer el perfil de susceptibilidad in vitro de los aislados clínicos de Microsporum canis de pacientes pediátricos que asisten a la Consulta de Micología del Servicio de Dermatología del Hospital Universitario de Caracas, a cinco antifúngicos a través del método del CLSI (M38-A2). De un total de 50 aislados de dermatofitos, el rango de los valores de concentración mínima inhibitoria en µg/ml (CMI) para Griseofulvina, Itraconazol, Voriconazol, Terbinafina y Anfotericina B fueron respectivamente: <0,03 ­ 0,125; <0,0019 ­ 0,0078; <0,0019 ­ 0,0078; <0,0019 ­ 0,0156 y 0,03 ­ 0,5. Por método visual se determinaron los puntos de corte epidemiológicos (PCE) para los 5 antifúngicos en estudio obteniéndose los siguientes datos: Griseofulvina ≤ 0,125, Itraconazol ≤ 0, 0039, Voriconazol ≤0,0078, Terbinafina ≤ 0, 0156 µg/ml y Anfotericina B ≤ 0, 5. En este estudio se determinó la susceptibilidad de los aislados a todos los antifúngicos en estudio, demostrando una alta actividad in vitro para el tratamiento de Tinea capitis.

The dermatophytes are frequently superficial mycoses in humans, are caused by fungi of the genera: Trichophyton, Microsporum and Epidermophyton. In Venezuela are the main reasons for dermatological consultation, constituting a public health problem because of its high morbidity. The aim of the study was to determine in vitro susceptibility of clinical isolates of Microsporum canis of pediatric patients attending to dermatology Caracas University Hospital, five antifungal by CLSI method (M38 -A2). The total of 50 isolates dermatophytes, the range of values of minimum inhibitory concentration (CMI) in µg/ml for Griseofulvin, Itraconazole, Voriconazole, Terbinafine and Amphotericin B were: <0.03 ­ 0.125; <0.0019 ­ 0.0078; <0.0019 ­ 0.0078; <0.0019 ­ 0.0156 and 0.03 ­ 0.5. For visual were determined epidemiological cut-off (PCE) for the 5 antifungal study obtained the following data: Griseofulvina ≤ 0.125, Itraconazol ≤ 0.0039, Voriconazol ≤0.0078, Terbinafina ≤ 0.0156 µg/ml and Anfotericina B ≤ 0.5. In this study we determined the susceptibility of isolates to all the antifungal study, demonstrating a high activity in vitro for the treatment of tinea capitis.