Antifungal susceptibility testing of Malassezia yeast: comparison of two different methodologies.

All Malassezia species are lipophilic; thus, modifications are required in susceptibility testing methods to ensure their growth. Antifungal susceptibility of Malassezia species using agar and broth dilution methods has been studied. Currently, few tests using disc diffusion methods are being performed. The aim was to evaluate the in vitro susceptibility of Malassezia yeast against antifungal agents using broth microdilution and disc diffusion methods, then to compare both methodologies. Fifty Malassezia isolates were studied. Microdilution method was performed as described in reference document and agar diffusion test was performed using antifungal tablets and discs. To support growth, culture media were supplemented. To correlate methods, linear regression analysis and categorical agreement was determined. The strongest linear association was observed for fluconazole and miconazole. The highest agreement between both methods was observed for itraconazole and voriconazole and the lowest for amphotericin B and fluconazole. Although modifications made to disc diffusion method allowed to obtain susceptibility data for Malassezia yeast, variables cannot be associated through a linear correlation model, indicating that inhibition zone values cannot predict MIC value. According to the results, disc diffusion assay may not represent an alternative to determine antifungal susceptibility of Malassezia yeast.

Identificación y sensibilidad antifúngica in vitro de Candida spp. de origen vaginal a fluconazol, clotrimazol y nistatina / Identification and in vitro antifungal susceptibility of vaginal Candida spp. isolates to fluconazole, clotrimazole and nystatin

Objetivo. Identificar especie y determinar la sensibilidad in vitro a clotrimazol, fluconazol y nistatina de 145 aislamientos de Candida spp. Material y métodos. Se utilizó un método de microdilución en caldo (M27-A3) para determinar la concentración inhibitoria mínima (CMI) y además las CMI50 y CMI90 de los antifúngicos. De los 145 aislamientos, 126 correspondieron a C. albicans, 16 C. glabrata, 2 C. parapsilosis y 1 C. tropicalis. Resultados. La CMI50 y CMI90 de fluconazol frente C. albicans fueron de 0,25 mg/L y 1 mg/L y para C. glabrata de 8 y 16 mg/L, respectivamente. Cinco aislados de C. albicans y un aislado de C. tropicalis fueron resistentes a fluconazol (M27- S4). Las CIM50 y CIM90 de clotrimazol frente a C. albicans fueron 0,03 mg/L y 0,06 mg/L y para C. glabrata de 0,25 mg/L y 1 mg/L, mientras que para nistatina fueron de 1 mg/L y de 2 mg/L, respectivamente para C. albicans y C. glabrata. Cinco aislados de C. glabrata y 1 de C. tropicalis fueron resistentes a clotrimazol. Conclusión. En este estudio, C. albicans es la levadura más frecuentemente aislada, seguida de C glabrata. Los antifúngicos evaluados resultaron ser activos in vitro para las cepas aisladas, excepto en 6 aislados para fluconazol y 6 para clotrimazol (AU)

Objective. The aim of this study was to identify and determine the in vitro antifungal susceptibility testing to clotrimazole, fluconazole, and nystatin of 145 clinical isolates of Candida spp. Material and methods. M27-A3 microdilution method was used to determine minimal inhibitory concentrations (MIC) and partial MICs (MIC50 and MIC90) of drugs. A total of 145 isolates were studied, 126 were C. albicans, 16 C. glabrata, 2 C. parapsilosis y 1 C. tropicalis. Results. MIC50 and MIC90 for FLZ against C. albicans were 0.25 mg/L and 1 mg/L respectively and for C. glabrata was achieved at 8 mg/L and 16 mg/L for fluconazole. Five isolates of C. albicans and one isolate of C. tropicalis were in vitro resistant to fluconazole (M27-S4). In C. albicans MIC50 and MIC90 for clotrimazole were of 0.03 mg/L and 0.06 mg/L, respectively. These values for C. glabrata were 0.25 mg/L and 1 mg/L, respectively. Five C. glabrata and 1 C. tropicalis were in vitro resistant to clotrimazole. MIC50 and MIC90 of nystatin were of 1 mg/L and 2 mg/L, respectively for C. albicans and C. glabrata. Conclusion. In this study, C. albicans is the most frequently isolated yeast, followed by C glabrata. The antifungals tested were found to be in vitro active for the isolates, except for 6 isolates for fluconazole and 6 to clotrimazole (AU)

La utilidad clínica de los derivados triazólicos en el tratamiento de las infecciones fúngicas / Clinical usefulness of triazole derivatives in the management of fungal infections

El tratamiento de las infecciones producidas por hongos se limita al uso de un reducido número de moléculas. Si bien, la anfotericina B aún sigue siendo considerada como el antifúngico de referencia, para el tratamiento de estas infecciones, la toxicidad aguda y crónica que produce así como el fallo renal limitan su uso y de alguna manera supuso un empuje a la investigación de nuevas familias de sustancias que pudieran ser empleadas en clínica. Una de esas familias es la de los derivados azólicos, descubierta en la década de los años 70 que fue introducida en la práctica clínica en la década posterior. Aun siendo la familia de antifúngicos más prolífica, la investigación sobre nuevas moléculas más seguras y con un mejor perfil farmacológico a la vez que presenten una mayor actividad frente a un amplio espectro de hongos patógenos y con la mayor cantidad rutas de administración (AU)

Current therapy for mycoses is limited to the use of a relative reduced number of antifungal drugs. Although amphotericin B still remains considered as the “gold standard” for treatment, acute and chronic toxicity, such as impairment of renal function, limits its use and enhances the investigation and clinical use other chemical families of antifungal drugs. One of these chemical class of active drugs are azole derivatives, discovered in 70s and introduced in clinical practice in 80s. Being the most prolific antifungal class, investigation about more molecules, with a safer and better pharmacological profile, active against a wide spectrum of fungi, with a wide range of administration routes gives us some azole representatives (AU)

Perfil de sensibilidad antifúngica in vitro de Scopulariopsis brevicaulis aislados de onicomicosis / In vitro antifungal susceptibility profile of Scopulariopsis brevicaulis isolated from onychomycosis

Se ha estudiado el perfil de actividad antifúngica in vitro de amorolfina (AMR), bifonazol (BFZ), clotrimazol (CLZ), econazol (ECZ), fluconazol (FNZ), itraconazol (ITZ), ketoconazol (KTZ), miconazol (MNZ), oxiconazol (OXZ), tioconazol (TCZ) y terbinafina (TRB) frente a 26 aislamientos clínicos de Scopulariopsis brevicaulis obtenidos de muestras clínicas de pacientes con onicomicosis, por medio de un método estandarizado de microdilución. A pesar de que este hongo filamentoso ha sido descrito como resistente frente a un amplio espectro de antifúngicos, los datos obtenidos muestran una mejor actividad fungistática in vitro de AMR, OXZ y TRB (0,08; 0,3 y 0,35 mg/L, respectivamente) en comparación con la de CLZ (0,47 mg/L), ECZ (1,48 mg/L), MNZ (1,56 mg/L, BFZ (2,8 mg/L), TCZ (3,33 mg/L), KTZ (3,73 mg/L). FNZ (178,47 mg/L) e ITZ (4,7 mg/L) mostraron una reducida actividad antifúngica in vitro. Las CMIs obtenidas muestran la reducida sensibilidad in vitro en general de S. brevicaulis a los antifúngicos utilizados y que son de posible uso para el tratamiento de las onicomicosis con la excepción de AMR, OXZ y TRB (AU9

We studied the in vitro antifungal activity profile of amorolfine (AMR), bifonazole (BFZ), clotrimazole (CLZ), econazole (ECZ), fluconazole (FNZ), itraconazole (ITZ), ketoconazole (KTZ), miconazole (MNZ), oxiconazole (OXZ), tioconazole (TCZ) and terbinafine (TRB) against 26 clinical isolates of Scopulariopsis brevicaulis from patients with onychomycosis by means of an standardized microdilution method. Although this opportunistic filamentous fungi was reported as resistant to several broad-spectrum antifungals agents, obtained data shows a better fungistatic in vitro activity of AMR, OXZ and TRB (0.08, 0.3, and 0.35 mg/L, respectively) in comparison to that of CLZ (0.47 mg/L), ECZ (1.48 mg/L), MNZ (1.56 mg/L, BFZ (2.8 mg/L), TCZ (3.33 mg/L), KTZ (3.73 mg/L). FNZ (178.47 mg/L) and ITZ (4.7 mg/L) showed a reduced in vitro antifungal activity against S. brevicaulis. Obtained MICs show the low in vitro antifungal susceptibility of S. brevicaulis to topical drugs for onychomycosis management, with exceptions (AMR, OZX and TRB) (AU)

[Clinical usefulness of triazole derivatives in the management of fungal infections]. / La utilidad clínica de los derivados triazólicos en el tratamiento de las infecciones fúngicas.

Current therapy for mycoses is limited to the use of a relative reduced number of antifungal drugs. Although amphotericin B still remains considered as the "gold standard" for treatment, acute and chronic toxicity, such as impairment of renal function, limits its use and enhances the investigation and clinical use other chemical families of antifungal drugs. One of these chemical class of active drugs are azole derivatives, discovered in 70s and introduced in clinical practice in 80s. Being the most prolific antifungal class, investigation about more molecules, with a safer and better pharmacological profile, active against a wide spectrum of fungi, with a wide range of administration routes gives us some azole representatives.

[In vitro antifungal susceptibility profile of Scopulariopsis brevicaulis isolated from onychomycosis]. / Perfil de sensibilidad antifúngica in vitro de Scopulariopsis brevicaulis aislados de onicomicosis.

We studied the in vitro antifungal activity profile of amorolfine (AMR), bifonazole (BFZ), clotrimazole (CLZ), econazole (ECZ), fluconazole (FNZ), itraconazole (ITZ), ketoconazole (KTZ), miconazole (MNZ), oxiconazole (OXZ), tioconazole (TCZ) and terbinafine (TRB) against 26 clinical isolates of Scopulariopsis brevicaulis from patients with onychomycosis by means of an standardized microdilution method. Although this opportunistic filamentous fungi was reported as resistant to several broad-spectrum antifungals agents, obtained data shows a better fungistatic in vitro activity of AMR, OXZ and TRB (0.08, 0.3, and 0.35 mg/L, respectively) in comparison to that of CLZ (0.47 mg/L), ECZ (1.48 mg/L), MNZ (1.56 mg/L, BFZ (2.8 mg/L), TCZ (3.33 mg/L), KTZ (3.73 mg/L). FNZ (178.47 mg/L) and ITZ (4.7 mg/L) showed a reduced in vitro antifungal activity against S. brevicaulis. Obtained MICs show the low in vitro antifungal susceptibility of S. brevicaulis to topical drugs for onychomycosis management, with exceptions (AMR, OZX and TRB).

Evaluación del perfil de sensibilidad in vitro de aislamientos clínicos deTrichophyton mentagrophytes y Trichophyton rubrum en Santiago, Chile / Evaluation of the in vitro susceptibility pattern of clinical isolates of Trichophyton mentagrophytes and Trichophyton rubrum in Santiago, Chile

Antecedentes: Los dermatofitos son un grupo de hongos queratinolíticos que producen infecciones denominadas dermatofitosis o tiñas. En Chile, los dermatofitos aislados con mayor frecuencia son Trichophyton rubrumy Trichophyton mentagrophytes en la población adulta, y Microsporum canis en niños prepúberes. Para el tratamiento de estas micosis se emplean antifúngicos tópicos y orales como la griseofulvina, antifúngicos azólicos como el clotrimazol, el itraconazol o el fluconazol, alilaminas como la terbinafina, y nuevas moléculas antifúngicas. Objetivos: Evaluar la sensibilidad in vitro de los dermatofitos frente a cinco antifúngicos y establecer posibles cambios respecto a estudios anteriores. Métodos: Se estudiaron 62 dermatofitos obtenidos de muestras clínicas (marzo-junio de 2010). Se utilizó el método de microdilución en caldo (M38-A2). Resultados: El rango de CMI para el fluconazol fue de 0,25-1 μg/ml; 0,03-0,06 μg/ml para el clotrimazol, la terbinafina y el itraconazol, y 0,015-0,03 μg/ml para la griseofulvina frente a T. rubrum y T. mentagrophytes. Excepto para le fluconazol, no se encontraron diferencias estadísticas significativas en los rangos de sensibilidad antifúngica. Conclusiones: Los valores de CMI para el fluconazol fueron los más altos (0,25-1 μg/ml) de todas las sustancias ensayadas, habiendo diferencias estadísticamente significativas entre este y el resto de antifúngicos. No hubo cepas resistentes a los antifúngicos analizados, y tampoco se encontraron cambios en el perfil de sensibilidad antifúngica in vitro en relación con estudios anteriores realizados en Chile (AU)

Background: Dermatophytes are a group of keratinophilic fungi able to produce dermatophytosis or tinea infections. In Chile, Trichophyton rubrum and Trichophyton mentagrophytes are the ones most commonly isolated in adults, while Microsporum canis is found among children. Treatment of these infections is usually with topical or oral antifungals, such as griseofulvin or azole derivatives (clotrimazole, itraconazole, fluconazole), allylamines (terbinafine) or new drugs that are available. Aims: Evaluation of the in vitro susceptibility of dermatophytes to five antifungal agents and the comparison of the susceptibility pattern with that of previous years. Methods: Sixty-two clinical isolates of dermatophyte fungi were studied (March-June 2010). The CLSI M38-A2 micromethod was used. Results: Fluconazole MIC values for T. rubrum and T. mentagrophytes varied between 0.25 and 1 μg/ml; MIC range to clotrimazole, terbinafine and itraconazole was 0.03-0.06 μg/ml, and MIC values for griseofulvin were 0.015-0.03 μg/ml. No statistically significant differences were found between susceptibility patterns, except for fluconazole. Conclusions: Fluconazole was less active in comparison with other drugs tested (0.25-1 μg/ml). None of the isolates were resistant to any of the drugs, and no changes in the susceptibility pattern were observed when comparing the results with data previously reported concerning dermatophytes in Chile (AU)

[Evaluation of the in vitro susceptibility pattern of clinical isolates of Trichophyton mentagrophytes and Trichophyton rubrum in Santiago, Chile]. / Evaluación del perfil de sensibilidad in vitro de aislamientos clínicos de Trichophyton mentagrophytes y Trichophyton rubrum en Santiago, Chile.

BACKGROUND: Dermatophytes are a group of keratinophilic fungi able to produce dermatophytosis or tinea infections. In Chile, Trichophyton rubrum and Trichophyton mentagrophytes are the ones most commonly isolated in adults, while Microsporum canis is found among children. Treatment of these infections is usually with topical or oral antifungals, such as griseofulvin or azole derivatives (clotrimazole, itraconazole, fluconazole), allylamines (terbinafine) or new drugs that are available. AIMS: Evaluation of the in vitro susceptibility of dermatophytes to five antifungal agents and the comparison of the susceptibility pattern with that of previous years. METHODS: Sixty-two clinical isolates of dermatophyte fungi were studied (March-June 2010). The CLSI M38-A2 micromethod was used. RESULTS: Fluconazole MIC values for T. rubrum and T. mentagrophytes varied between 0.25 and 1 µg/ml; MIC range to clotrimazole, terbinafine and itraconazole was 0.03-0.06 µg/ml, and MIC values for griseofulvin were 0.015-0.03 µg/ml. No statistically significant differences were found between susceptibility patterns, except for fluconazole. CONCLUSIONS: Fluconazole was less active in comparison with other drugs tested (0.25-1 µg/ml). None of the isolates were resistant to any of the drugs, and no changes in the susceptibility pattern were observed when comparing the results with data previously reported concerning dermatophytes in Chile.

Una nueva generación de antifúngicos para el tratamiento de las micosis superficiales / A new generation of antifungals for the treatment of dermatomycosis

Las infecciones fúngicas superficiales responden bien a los tratamientos habituales en la mayoría de los casos pero, en determinadas situaciones, constituyen un problema. En su mayoría se trata de infecciones producidas por levaduras del género Candida y Malassezia y por hongos dermatofitos. Estas infecciones han visto incrementada su prevalencia junto con la selección de determinadas especies, la reducción de la sensibilidad a los antifúngicos y la aparición de fenómenos de resistencia in vitro e in vivo. La investigación para encontrar el antifúngico ideal aún continúa y en este sentido actualmente se están ensayando distintas estrategias de investigación sobre drogas para el tratamiento sistémico y tópico de las dermatomicosis.

Superficial fungal infections frequently caused by Candida spp. and Malassezia spp yeasts and dermatophytes fungi, have good response to common treatments in the majority of cases, but in some cases failure are described. Prevalence of these infections has been increased with the selection of certain species, reduced sensitivity to antifungal agents and the emergence of in vitro and in vivo resistance phenomena. The research to find the ideal antifungal still continues and in this sense are being currently tested different strategies for research on systemic and topical drugs for dermatomycosis treatment.

Producción de fosfolipasa y proteinasa en cepas de Malassezia pachydermatis aisladas de perros con otitis y sin otitis / Phospholipase and proteinase production by Malassezia pachydermatis isolated in dogs with and without otitis

Antecedentes. Malassezia pachydermatis forma parte de la microbiota cutánea de perros y gatos. M. pachydermatis se ha asociado frecuentemente a otitis externa y dermatitis seborreicas, sobre todo en el perro, y con menor frecuencia en el gato. M. pachydermatis podría actuar como patógeno cuando existen alteraciones en los mecanismos físicos, químicos o inmunológicos de la piel. Se han identificado diversos factores de virulencia como la capacidad de producir estearasas, lipasas, lipooxigenasas, proteinasas, condroitinsulfatasas e hialuronidasas. Objetivos. Se ha estudiado la actividad fosfolipasa medida a pH 6,3 y la actividad proteinasa medida a pH 6,3 y pH 6,8 (pH de oídos de perros con otitis) de cepas de M. pachydermatis aisladas de perros con otitis y sin otitis. Métodos. Se ha estudiado la actividad fosfolipasa mediante un método semicuantitativo con yema de huevo y la actividad proteinasa mediante un método semicuantitativo con agar albúmina sérica bovina. Se ha realizado el estudio en 96 aislamientos de M. pachydermatis, 43 de ellos aislados de perros sin sintomatología clínica de otitis y 52 aislados de perros con otitis. Resultados. Se observó que el 75,8% de los aislamientos presentaron actividad fosfolipasa a pH 6,3 y el 81% presentaron actividad proteinasa medida a pH 6,3, y el 97,9% a pH 6,8. Se detectó una mayor actividad fosfolipasa en cepas aisladas de perros con otitis. Con respecto a la actividad proteinasa, esta fue mayor a pH 6,8. Conclusiones. Estos hallazgos sugieren que la actividad fosfolipasa podría jugar un papel importante en la invasión de los tejidos del hospedador, por lo menos en la otitis crónica canina. Con respecto a la actividad proteinasa, estos hallazgos podrían ayudar a mejorar la terapéutica de la otitis cuando está implicada M. pachydermatis en el proceso, ajustando a pH bajos los tratamientos aplicados (AU)

Influencia del grupo ecológico sobre la sensibilidad in vitro de los hongos dermatofitos a los antifúngicos / Influence of the ecological group on the in vitro antifungal susceptibility of dermatophytic fungi

Antecedentes. Los hongos dermatofitos se agrupan en geofílicos (suelo), zoofílicos (animales) y antropofílicos (humanos), dependiendo de la fuente de queratina que pueden utilizar como sustrato nutritivo energético. Objetivos. Se ha estudiado la sensibilidad in vitro de aislamientos clínicos de hongos dermatofitos pertenecientes a los 3 grupos ecológicos frente a antifúngicos utilizados para el tratamiento tópico de las dermatofitosis, con el fin de conocer la influencia del grupo en esta actividad. Métodos. Mediante un micrométodo de dilución en medio líquido se determinó la actividad antifúngica in vitro de 9 antifúngicos de uso tópico: amorolfina (AMR), bifonazol (BFZ), clotrimazol, econazol, ketoconazol, miconazol, oxiconazol, terbinafina (TRB) y tioconazol frente a 124 aislamientos clínicos de hongos dermatofitos pertenecientes a los 3 grupos ecológicos (antropofílicos, zoofílicos y geofílicos). Resultados. La actividad antifúngica in vitro mostró diferencias según el grupo ecológico en el que se dividen los hongos dermatofitos, observándose también un patrón especie dependiente. Conclusiones. Los derivados azólicos mostraron un patrón de actividad similar entre ellos, con mayor actividad frente a los antropofílicos > zoofílicos > geofílicos. La actividad de TRB y AMR, por el contrario, fue: zoofílicos > antropofílicos > geofílicos. TRB y AMR fueron las más activas frente a los 3 grupos y BFZ la menos activa(AU)

Background. Dermatophytes can be divided into geophilic (soil), zoophilic (animals) and anthropophilic (humans) strains, depending on the source of the keratin that they use for nutritional purposes. Aims. The in vitro susceptibility of clinical isolates of dermatophyte fungi has been studied in the 3 ecological groups with several antifungal agents for the topical management of dermatophytoses in order to determine their relationship with the ecological group. Methods. A standardised dilution micromethod in a liquid medium was used for the determination of the in vitro antifungal activity of 9 topical antifungal drugs: amorolfine (AMR), bifonazole (BFZ), clotrimazole, econazole, ketoconazole, miconazole, oxiconazole, terbinafine (TRB) and tioconazole. The in vitro activity was obtained against 124 clinical isolates of dermatophyte moulds from the anthropophilic, zoophilic and geophilic ecological groups. Results. The in vitro antifungal activity was different depending on the ecological group, although a species-dependent profile was also observed. Conclusions. Azole derivatives showed a similar antifungal profile, being more active against anthropophilic dermatophytes > zoophilic > geophilic. Activity of TRB and AMR was different from that of azole derivatives (zoophilic > anthropophilic > geophilic). A higher in vitro antifungal activity against the 3 ecological groups was observed with TRB and AMR, whilst BFZ was the less active drug(AU)

Sertaconazole: an antifungal agent for the topical treatment of superficial candidiasis.

Sertaconazole is a useful antifungal agent against mycoses of the skin and mucosa, such as cutaneous, genital and oral candidiasis and tinea pedis. Its antifungal activity is due to inhibition of the ergosterol biosynthesis and disruption of the cell wall. At higher concentrations, sertaconazole is able to bind to nonsterol lipids of the fungal cell wall, increasing the permeability and the subsequent death of fungal cells. Fungistatic and fungicidal activities on Candida are dose-dependent. The antifungal spectrum of sertaconazole includes deramophytes, Candida, Cryptococcus, Malassezia and also Aspergillus, Scedosporium and Scopulariopsis. Sertaconazole also shows an antimicrobial activity against streptococci, staphylococci and protozoa (Trichomonas). In clinical trials including patients with vulvovaginal candidiasis, a single dose of sertaconazole produced a higher cure rate compared with other topical azoles such as econazole and clotrimazole, in shorter periods. Sertaconazole has shown an anti-inflammatory effect that is very useful for the relief of unpleasant symptoms.

In vitro antifungal activity of topical and systemic antifungal drugs against Malassezia species.

The strict nutritional requirements of Malassezia species make it difficult to test the antifungal susceptibility. Treatments of the chronic and recurrent infections associated with Malassezia spp. are usually ineffective. The objective of this study was to obtain in vitro susceptibility profile of 76 clinical isolates of Malassezia species against 16 antifungal drugs used for topical or systemic treatment. Isolates were identified by restriction fragment length polymorphism. Minimal inhibitory concentrations (MIC) were obtained by a modified microdilution method based on the Clinical Laboratory Standards Institute reference document M27-A3. The modifications allowed a good growth of all tested species. High in vitro antifungal activity of most tested drugs was observed, especially triazole derivatives, except for fluconazole which presented the highest MICs and widest range of concentrations. Ketoconazole and itraconazole demonstrated a great activity. Higher MICs values were obtained with Malassezia furfur indicating a low susceptibility to most of the antifungal agents tested. Malassezia sympodialis and Malassezia pachydermatis were found to be more-susceptible species than M. furfur, Malassezia globosa, Malassezia slooffiae and Malassezia restricta. Topical substances were also active but provide higher MICs than the compounds for systemic use. The differences observed in the antifungals activity and interspecies variability demonstrated the importance to studying the susceptibility profile of each species to obtain reliable information for defining an effective treatment regimen.

[Phospholipase and proteinase production by Malassezia pachydermatis isolated in dogs with and without otitis]. / Producción de fosfolipasa y proteinasa en cepas de Malassezia pachydermatis aisladas de perros con otitis y sin otitis.

BACKGROUND: Malassezia pachydermatis is part of the skin microbiota of dogs and cats. M. pachydermatis has been associated with external otitis and seborrhoeic dermatitis, reported more often in dogs than in cats. When the physical, chemical or immunological mechanisms of the skin are altered, M. pachydermatis could act as a pathogen. Thus, several virulence factors, such as the ability to produce esterase, lipase, lipoxygenase, protease, chondroitin sulphatase, and hyaluronidase, have been studied. AIMS: In the present study, we aim to identify the phospholipase activity measured at pH 6.3, and the proteinase activity measured at pH 6.3 and pH 6.8 (pH from ears of dogs with external otitis) of M. pachydermatis strains isolated from dogs with and without external otitis. METHODS: The phospholipase activity was measured using a semi-quantitative method with egg yolk, and the proteinase activity with a semi-quantitative method using bovine serum albumin agar. The study was performed on 96 isolates of M. pachydermatis, 43 isolated from dogs without clinical symptoms of otitis, and 52 isolated from dogs with otitis. RESULTS: In our study, 75.8% of the isolates showed phospholipase activity at pH 6.3, and 81 and 97.9% of them showed proteinase activity measured at pH 6.3 and 6.8, respectively. A higher phospholipase activity was detected in strains isolated from dogs with otitis. The proteinase activity was increased at a pH of 6.8 (97.9%) in comparison to a pH of 6.3 (81%). CONCLUSIONS: Our results suggest that the phospholipase activity may play an important role in the invasion of host tissues in chronic canine otitis cases. The proteinase activity results obtained in this study suggest that a reduction in the pH of the treatment may improve its efficacy in the resolution of M. pachydermatis otitis.

[Influence of the ecological group on the in vitro antifungal susceptibility of dermatophytic fungi]. / Influencia del grupo ecológico sobre la sensibilidad in vitro de los hongos dermatofitos a los antifúngicos.

BACKGROUND: Dermatophytes can be divided into geophilic (soil), zoophilic (animals) and anthropophilic (humans) strains, depending on the source of the keratin that they use for nutritional purposes. AIMS: The in vitro susceptibility of clinical isolates of dermatophyte fungi has been studied in the 3 ecological groups with several antifungal agents for the topical management of dermatophytoses in order to determine their relationship with the ecological group. METHODS: A standardised dilution micromethod in a liquid medium was used for the determination of the in vitro antifungal activity of 9 topical antifungal drugs: amorolfine (AMR), bifonazole (BFZ), clotrimazole, econazole, ketoconazole, miconazole, oxiconazole, terbinafine (TRB) and tioconazole. The in vitro activity was obtained against 124 clinical isolates of dermatophyte moulds from the anthropophilic, zoophilic and geophilic ecological groups. RESULTS: The in vitro antifungal activity was different depending on the ecological group, although a species-dependent profile was also observed. CONCLUSIONS: Azole derivatives showed a similar antifungal profile, being more active against anthropophilic dermatophytes > zoophilic > geophilic. Activity of TRB and AMR was different from that of azole derivatives (zoophilic > anthropophilic > geophilic). A higher in vitro antifungal activity against the 3 ecological groups was observed with TRB and AMR, whilst BFZ was the less active drug.

In vitro activities of new triazole antifungal agents, posaconazole and voriconazole, against oral Candida isolates from patients suffering from denture stomatitis.

Denture stomatitis is often treated with antifungal agents but recurrences or new episodes are common, and certain episodes can be resistant. New triazoles, such as posaconazole and voriconazole, may represent useful alternatives for management. In vitro activities of amphotericin B, nystatin, miconazole, fluconazole, itraconazole, posaconazole and voriconazole against 150 oral Candida (101 C. albicans, 18 C. tropicalis, 12 C. glabrata, 11 C. guilliermondii, 4 C. parapsilosis, 2 Saccharomyces cerevisiae, 1 C. dubliniensis and 1 C. krusei) from 100 denture wearers were tested by the CLSI M27-A3 method. Resistant isolates were retested by Sensititre YeastOne and Etest. Most antifungal agents were very active. However, 4 C. glabrata (33.3%), 2 C. tropicalis (11.1%), 6 C. albicans (5.6%) and 1 C. krusei were resistant to itraconazole. Posaconazole was active against 143 yeast isolates (95.3%): 6 C. albicans (5.9%) and 1 C. tropicalis (5.6%) were resistant. Geometric mean MICs were 0.036 µg/ml for C. parapsilosis, 0.062 µg/ml for C. albicans, 0.085 µg/ml for C. tropicalis, 0.387 µg/ml for C. guilliermondii and 0.498 µg/ml for C. glabrata. Voriconazole was active against 148 isolates (98.7%) with geometric mean MICs ranging from 0.030 µg/ml for C. parapsilosis, 0.042 µg/ml for C. albicans, 0.048 µg/ml for C. tropicalis, 0.082 µg/ml for C. guilliermondii, to 0.137 µg/ml for C. glabrata. Only 2 C. albicans (2%) were resistant to voriconazole showing cross-resistance to other azoles. Posaconazole and voriconazole have excellent in vitro activities against all Candida isolates and could represent useful alternatives for recalcitrant or recurrent candidiasis.

Sertaconazole nitrate shows fungicidal and fungistatic activities against Trichophyton rubrum, Trichophyton mentagrophytes, and Epidermophyton floccosum, causative agents of tinea pedis.

The fungistatic and fungicidal activities of sertaconazole against dermatophytes were evaluated by testing 150 clinical isolates of causative agents of tinea pedis, Trichophyton rubrum, Trichophyton mentagrophytes, and Epidermophyton floccosum. The overall geometric means for fungistatic and fungicidal activities of sertaconazole against these isolates were 0.26 and 2.26 µg/ml, respectively, although values were higher for T. mentagrophytes than for the others. This is the first comprehensive demonstration of the fungicidal activity of sertaconazole against dermatophytes.

Prevalence and antifungal susceptibility patterns of new cryptic species inside the species complexes Candida parapsilosis and Candida glabrata among blood isolates from a Spanish tertiary hospital.

OBJECTIVES: There is scarce information on the clinical relevance and antifungal susceptibility of Candida bracarensis, Candida nivariensis, Candida orthopsilosis and Candida metapsilosis. The objective of this study was to assess the prevalence and in vitro antifungal susceptibility of these cryptic species among 173 blood isolates previously identified as Candida glabrata or Candida parapsilosis at the Hospital of Cruces (Barakaldo, Spain). The survey was extended to 518 clinical isolates from the culture collection of the Universidad del País Vasco-Euskal Herriko Unibertsitatea (UPV-EHU; Bilbao, Spain). METHODS: In vitro susceptibilities to 5-fluorocytosine, amphotericin B, anidulafungin, caspofungin, fluconazole, itraconazole, micafungin, posaconazole and voriconazole were tested. RESULTS: All isolates of C. glabrata were identified as C. glabrata sensu stricto. Inside the C. parapsilosis complex, 2.4% of isolates from the Hospital of Cruces and 5.8% from the UPV-EHU were C. metapsilosis or C. orthopsilosis. Of 457 isolates, 435 (95.19%) were C. parapsilosis sensu stricto, 11 (2.41%) C. metapsilosis and 11 (2.41%) C. orthopsilosis. Only seven blood isolates were C. metapsilosis (0.44%) or C. orthopsilosis (1.09%). These cryptic species were also isolated from other relevant clinical specimens. Four C. parapsilosis sensu stricto (5.6%) were susceptible dose-dependent, and one was resistant to both fluconazole and voriconazole (1.4%). Moreover, 19 isolates of C. parapsilosis sensu stricto (26.4%) were intermediately susceptible to itraconazole and higher concentrations of echinocandins were needed to inhibit this species. Most C. orthopsilosis and C. metapsilosis were susceptible to all antifungal agents tested, but one otic isolate of C. metapsilosis was resistant to fluconazole and 5-fluorocytosine. CONCLUSIONS: C. metapsilosis and C. orthopsilosis are associated with human disease and show a different antifungal susceptibility profile compared with C. parapsilosis sensu stricto.

Epidemiología de las fungemias en un hospital pediátrico de alta complejidad / Epidemiology of fungaemia in a paediatric hospital of high complexity

Antecedentes. Se realizó un estudio retrospectivo desde septiembre de 2001 a septiembre de 2003 de las fungemias por levaduras en el Hospital Nacional de Pediatría Prof. Dr. J. Garrahan, de Buenos Aires. Objetivos. Conocer la distribución de las especies de levaduras de interés médico y evaluar el perfil de sensibilidad in vitro a los antifúngicos. Métodos. Se determinó la concentración mínima inhibitoria (CMI) según el documento M27-A2 del CLSI, y además, las curvas de letalidad frente a la anfotericina B. Resultados-Conclusiones. Se aislaron Candida parapsilosis (32,6% de los aislamientos), Candida albicans (26,5%), Candida tropicalis (24,5%), y otras especies de levaduras (16,4%). Los aislamientos de Candida fueron sensibles a los antifúngicos evaluados pero se detectaron, mediante el uso de curvas de letalidad, cepas tolerantes a la anfotericina B(AU)

Background. A retrospective study on the epidemiology of fungaemia due to yeasts of medical importance at the Hospital Nacional de Pediatría Prof. Dr. J. Garrahan, Buenos Aires was conducted between September 2001 and September 2003. Objectives. To learn the distribution of yeast species and to evaluate their in vitro antifungal susceptibility profile. Methods. The minimum inhibitory concentration (MIC) was determined according to the CLSI M27-A2 procedure, and time kill curves against amphotericin B were also performed. Results-Conclusions. The species isolated were Candida parapsilosis (32.6% of isolates); Candida albicans (26.5%), Candida tropicalis (24.5%), and other yeasts (16.4%). Candida isolates were susceptible to the antifungals evaluated, but amphotericin B-tolerant isolates were detected using time kill curves(AU)