Ketoconazole beyond antifungal activity: Bioinformatics-based hypothesis on lipid metabolism in dandruff and seborrheic dermatitis.

The role of Malassezia yeasts in dandruff and seborrheic dermatitis is unclear; however, antifungal therapy with ketoconazole is commonly used. We propose that ketoconazole shifts skin lipid profile, affects Malassezia lipid metabolism and favours biotin-producing bacteria. Biotin regulates inflammatory response and cell proliferation, contributing to symptom improvement.

Isolation of Malassezia spp. in HIV-positive patients with and without seborrheic dermatitis.

BACKGROUND: Malassezia, a skin saprophyte, is frequently isolated from patients with seborrheic dermatitis, which is one of the most common dermatoses in HIV-infected patients. Its role in pathophysiology has not been defined. OBJECTIVE: To determine whether patients living with HIV and seborrheic dermatitis have more Malassezia than those without seborrheic dermatitis. METHOD: This is an descriptive, observational, prospective cross-sectional study to which all adult patients living with HIV that attend the infectious disease outpatient clinic at the Dr. Manuel Gea González General Hospital were invited. Patients presenting with scale and erythema were included in Group 1, while patients without erythema were included in Group 2. Samples were taken from all patients for smear and culture. RESULTS: Thirty patients were included in each group. All patients with seborrheic dermatitis had a positive smear, with varying amounts of yeasts. In the control group, 36.7% of patients had a negative smear. The results are statistically significant, as well as the number of colonies in the cultures. Study limitations The study used a small sample size and the subspecies were not identified. CONCLUSIONS: Patients with clinical manifestations of seborrheic dermatitis have larger amounts of Malassezia. Further studies need to be performed to analyze if the greater amount is related to imbalances in the microbiota of the skin.

Isolation of Malassezia spp. in HIV-positive patients with and without seborrheic dermatitis

Abstract Background Malassezia, a skin saprophyte, is frequently isolated from patients with seborrheic dermatitis, which is one of the most common dermatoses in HIV-infected patients. Its role in pathophysiology has not been defined. Objective To determine whether patients living with HIV and seborrheic dermatitis have more Malassezia than those without seborrheic dermatitis. Method This is an descriptive, observational, prospective cross-sectional study to which all adult patients living with HIV that attend the infectious disease outpatient clinic at the Dr. Manuel Gea González General Hospital were invited. Patients presenting with scale and erythema were included in Group 1, while patients without erythema were included in Group 2. Samples were taken from all patients for smear and culture. Results Thirty patients were included in each group. All patients with seborrheic dermatitis had a positive smear, with varying amounts of yeasts. In the control group, 36.7% of patients had a negative smear. The results are statistically significant, as well as the number of colonies in the cultures.Study limitations The study used a small sample size and the subspecies were not identified. Conclusions Patients with clinical manifestations of seborrheic dermatitis have larger amounts of Malassezia. Further studies need to be performed to analyze if the greater amount is related to imbalances in the microbiota of the skin.

New perspectives on dandruff and seborrheic dermatitis: lessons we learned from bacterial and fungal skin microbiota.

The human body is inhabited by complex microbial communities, which positively impact different aspects of our health, and might also be related to the development of diseases. Progress in technologies, particularly sequencing methods and bioinformatics tools, has been crucial for the advances in this field. Microbial communities from skin can modulate immune response and protect the host against pathogens, and there are also data supporting their association with several skin conditions; including dandruff and seborrheic dermatitis. For decades, they have been thought to be related to Malassezia yeasts; however, the microbial role has not been elucidated, and their etiology remains poorly understood. This review discusses the recent findings in dandruff and seborrheic dermatitis and their relation to the skin microbiota. Data provided new perceptions to aid in the understanding of these skin disorders, broadening our view of their etiology and the possible roles of microbial communities in symptom development.

[In vitro antifungal activity of azoles and amphotericin B against Malassezia furfur by the CLSI M27-A3 microdilution and Etest® methods]. / Actividad antifúngica in vitro de azoles y anfotericina B frente a Malassezia furfur por el método de microdilución M27-A3 del CLSI y Etest®.

BACKGROUND: Malassezia furfur is a human skin commensal yeast that can cause skin and opportunistic systemic infections. Given its lipid dependant status, the reference methods established by the Clinical and Laboratory Standards Institute (CLSI) to evaluate antifungal susceptibility in yeasts are not applicable. AIMS: To evaluate the in vitro susceptibility of M. furfur isolates from infections in humans to antifungals of clinical use. METHODS: The susceptibility profile to amphotericin B, itraconazole, ketoconazole and voriconazole of 20 isolates of M. furfur, using the broth microdilution method (CLSI M27-A3) and Etest®, was evaluated. RESULTS: Itraconazole and voriconazole had the highest antifungal activity against the isolates tested. The essential agreement between the two methods for azoles antifungal activity was in the region of 60-85% and the categorical agreement was around 70-80%, while the essential and categorical agreement for amphotericin B was 10%. CONCLUSIONS: The azoles were the compounds that showed the highest antifungal activity against M. furfur, as determined by the two techniques used; however more studies need to be performed to support that Etest® is a reliable method before its implementation as a routine clinical laboratory test.

Malassezia intra-specific diversity and potentially new species in the skin microbiota from Brazilian healthy subjects and seborrheic dermatitis patients.

Malassezia yeasts are part of the resident cutaneous microbiota, and are also associated with skin diseases such as seborrheic dermatitis (SD). The role these fungi play in skin diseases and why they are pathogenic for only some individuals remain unclear. This study aimed to characterize Malassezia microbiota from different body sites in healthy and SD subjects from Brazil. Scalp and forehead samples from healthy, mild SD and severe SD subjects were collected. Non-scalp lesions from severe SD patients were also sampled. 5.8S rDNA/ITS2 amplicons from Malassezia sp. were analyzed by RFLP and sequencing. Results indicate that Malassezia microbiota did not group according to health condition or body area. Phylogenetic analysis revealed that three groups of sequences did not cluster together with any formally described species, suggesting that they might belong to potential new species. One of them was found in high proportions in scalp samples. A large variety of Malassezia subtypes were detected, indicating intra-specific diversity. Higher M. globosa proportions were found in non-scalp lesions from severe SD subjects compared with other areas, suggesting closer association of this species with SD lesions from areas other than scalp. Our results show the first panorama of Malassezia microbiota in Brazilian subjects using molecular techniques and provide new perspectives for further studies to elucidate the association between Malassezia microbiota and skin diseases.

Seborrheic dermatitis: predisposing factors and ITS2 secondary structure for Malassezia phylogenic analysis.

Seborrheic dermatitis (SD) is a chronic, widespread skin condition, which is considered a multifactorial disease influenced, in part, by Malassezia spp. opportunistic activities, as well as various endogenous and exogenous factors. Malassezia species are lipophilic, lipid-dependent yeasts that are members of the normal mycobiota of the human skin. Their isolation from SD lesions varies around the world and the study of the relationship among factors such as gender, age, immunosuppressive condition of the patient and SD development, can lead to a better understanding of this disease. To elucidate the association of age and gender with the development of SD and to precisely determine the Malassezia species involved in the disease, samples were obtained from 134 individuals, including individuals without lesions, human immunodeficiency virus positive patients, individuals with seborrheic dermatitis, and HIV patients with seborrheic dermatitis. Malassezia spp. were identified by phenotypic and genotypic methods and a phylogenetic analysis was performed using Bayesian inference. This study revealed that age and gender are not predisposing factors for SD development, and that the most frequent species of Malassezia related to SD development among the Colombian population is M. restricta. We also report the isolation of M. yamatoensis for the first time in Colombia, and propose an ITS2 secondary structure from Malassezia taxa that can be used for precise identification and to establish more robust phylogenetic relationships.

[Prevalence of Malassezia species associated with seborrheic dermatitis lesions in patients in Argentina]. / Prevalencia de especies de Malassezia asociadas a lesiones de dermatitis seborreica en pacientes de Argentina.

BACKGROUND: Seborrheic dermatitis (SD) is considered the second most frequently dermatosis associated with the genus Malassezia but little is the knowledge about the epidemiology of this association. AIMS: To determinate the prevalence of Malassezia species associated with SD and to analyse their distribution according to the location of the lesion on the body. METHODS: This study was performed in Resistencia city, located in a subtropical area in northeast Argentina. In this study, 226 skin samples from patients with lesions compatible with SD were studied. Age, gender and body sites lesion were recorded. Strains were identified by PCR-RFLP. RESULTS: One hundred and thirty-one positive cultures were obtained. Association of 2 species was detected in 10 cases; therefore, 141 strains were isolated. Malasezzia globosa (43.3%) was the most frequent species isolated, followed by Malasezzia furfur (20.6%), Malasezzia sympodialis (17%) and Malasezzia restricta (16.3%). Three isolates of Malasezzia slooffiae (2.1%) and one of Malasezzia pachydermatis (0.7%) were obtained. Statistical significance (P<0.05) was found between M. globosa and scalp. Malasezzia restricta was isolated only in head areas. CONCLUSIONS: This study suggests M. globosa is the most related species to SD. The prevalence of other species is different from that reported by other authors. Only M. globosa and M. restricta presented a pattern of relationship with the body sites of the lesions. It is noteworthy is the isolation of the zoophylic species M. pachydermatis. The Malassezia genus ecology and the pathogenic role of its species are still under study. This work is a contribution to this knowledge.

Genotyping by RAPD-PCR analyses of Malassezia furfur strains from pityriasis versicolor and seborrhoeic dermatitis patients.

Malassezia furfur is lypophilic yeast commonly associate with dermatological disorders. In the present work, we described the isolation of 47 M. furfur strains from three groups of patients: pityriasis versicolor (21 isolates), seborrhoeic dermatitis (15 isolates) and seborrhoeic dermatitis of the HIV positive patients (11 isolates). To investigate the identity of the strains at molecular level, DNA genomic of M. furfur strains were prepared and used to RAPD-PCR analyses. RAPD assay were carried out using two decamer primers and bands pattern generated were analyzed by an Unweighted Pair-Group Method (UPGMA). Dendrogram established a distinct differentiation between M. furfur isolates from pityriasis versicolor and seborrhoeic dermatitis patients with or without AIDS. We concluded that RAPD typing presented a high discriminatory power between strains studied in this work and can be applied in epidemiological investigation of skin disease causing by M. furfur.

[The use of calcofluor white for studying Malassezia species by direct microscopy]. / Empleo de blanco de calcoflúor para el estudio de las especies de Malassezia por microscopía directa.

Fungi of Malassezia genus are known as normal flora in human beings. However, different pathologies due to Malassezia, have been described. Traditionally, early diagnosis was delayed because of the difficulties in culture isolation of these organisms. The aim of this work, is to evaluate the technique of observation microscopy with calcofluor, for identification of Malassezia in both, clinical samples and isolates. In comparison to traditional method of direct examination with lactophenol-blue, calcofluor method offers an advantage because it turns easier the observation of fungal elements and its budding pattern. This technique contributes then, to identify species of Malassezia. The analysis of clinical specimens with calcofluor followed by observation under fluorescence microscopy is a simple and rapid method for the identification, and contribute therefore to the early diagnosis.

[Malassezia species isolated from skin diseases in a care center in the city of Buenos Aires, Argentina]. / Especies de Malassezia aisladas de patologías de piel en un centro asistencial de la ciudad de Buenos Aires, Argentina.

The epidemiology of Malassezia genus is poorly understood; geographical and population factors might have influence on the species distribution. The aim of this work was to determine the frequency of Malassezia species involved in skin diseases in a diagnostic center at Buenos Aires City. From 02/01/1999 to 10/31/2001, 456 skin specimens from 447 patients diagnosed as pityriasis versicolor, seborrheic dermatitis, foliculitis and atopic dermatitis, were analyzed by microscopic examination and culture. Malassezia spp was evidenced in 255 skin samples (55.9%) by microscopic analysis but it could be recovered from only 99 (38.8%) specimens. Malassezia species were isolated from 10 (3.9%) scarring lesions that were negative by microscopy. Among 109 isolates, M. sympodialis (58.7%) was the most frequent, followed by M. globosa and M. furfur (18.3% and 9.2%). Unique isolates (0.9%) of M. obtusa, M. slooffiae and M. restricta were recovered. Eleven isolates (10.1%) could not be identified because they had lost viability in the culture. This is the first study on Malassezia species associated to skin diseases in Argentina; further screening including other geographic regions of the country is necessary in order to confirm these results.

Caracterización de especies del género Malassezia en pacientes con dermitis seborreica y en controles / Characterization of species of the gender Malassezia in patients with seborrheic dermatitis and subjects without skin lesions

The yeast Malassezia spp has an established etiological role in pityriasis versicolor, folliculitis, systemic infections and onychomycosis. Aim: To assess the presence of Malassezia spp in patients with seborrheic dermatitis (SD), to find a correlation between Malassezia spp count and the severity of the disease and to compare the prevalence of the different Malassezia species in SD patients and subjects without skin lesions. Patients and methods: Scrapings of the face from 81 patients with SD (69 males) and 79 subjects (54 males) without skin lesions were obtained for a direct microscope examination and yeast culture. Results: The yeast Malassezia was found in 76% of SD patients and in 82% of subjects without skin lesions. There was a positive correlation between the number of yeasts found on direct examination and the clinical severity of lesions in SD patients. Although this correlation was statistically significant (p=0.046), the degree of association (rho=0.22) was weak. Fifty Malassezia species were identified. M globosa was found in 67% of SD patients, followed by M furfur and M sympodialis, each present in 16.5% of the SD patients. In subjects without skin lesions, the most prevalent species were M globosa (77%), followed by M sympodialis (12%), M slooffiae (7%) and M furfur (4%). Conclusions: The presence of the yeast Malassezia is not associated with the presence of skin lesions (Rev Méd Chile 2003; 131: 1295-300).

[Characterization of species of the gender Malassezia in patients with seborrheic dermatitis and subjects without skin lesions]. / Caracterización de especies del género Malassezia en pacientes con dermitis seborreica y en controles.

BACKGROUND: The yeast Malassezia spp has an established etiological role in pityriasis versicolor, folliculitis, systemic infections and onychomycosis. AIM: To assess the presence of Malassezia spp in patients with seborrheic dermatitis (SD), to find a correlation between Malassezia spp count and the severity of the disease and to compare the prevalence of the different Malassezia species in SD patients and subjects without skin lesions. PATIENTS AND METHODS: Scrapings of the face from 81 patients with SD (69 males) and 79 subjects (54 males) without skin lesions were obtained for a direct microscope examination and yeast culture. RESULTS: The yeast Malassezia was found in 76% of SD patients and in 82% of subjects without skin lesions. There was a positive correlation between the number of yeasts found on direct examination and the clinical severity of lesions in SD patients. Although this correlation was statistically significant (P = 0.046), the degree of association (rho = 0.22) was weak. Fifty Malassezia species were identified. M globosa was found in 67% of SD patients, followed by M furfur and M sympodialis, each present in 16.5% of the SD patients. In subjects without skin lesions, the most prevalent species were M globosa (77%), followed by M sympodialis (12%), M slooffiae (7%) and M furfur (4%). CONCLUSIONS: The presence of the yeast Malassezia is not associated with the presence of skin lesions.

Reclassificação taxonômica de espécies do gênero Malassezia: revisão da literatura sobre as implicações clinicolaboratoriais / Reclassification of Malassezia species: a review of its clinical and laboratory significance

O gênero Malassezia compreende leveduras lipofílicas e lipodependentes que recentemente sofreram mudanças em sua classificação taxonômica, com a introdução de quatro novas espécies: M. globosa, M. obtusa, M. slooffiae e M. restricta, além das espécies M. furfur, M. pachydermatis e M. sympodialis, já descritas. Estas leveduras estão associadas a vários quadros patológicos que incluem infecções como a pitiríase versicolor ou dermatoses, como dermatite seborréica e dermatite atópica, entre outros. Estes quadros eram, até pouco tempo atrás, considerados devidos exclusivamente à espécie M. furfur. Essas mudanças na classificação taxonômica de Malassezia levaram a uma reavaliação dos procedimentos laboratoriais que eram utilizados para a identificação do agente etiológico. Entre eles podemos citar o estudo e a caracterização morfológicas das espécies, sua tolerância térmica, suas necessidades nutricionias para determinados tipos de ácidos graxos, bem como a composição e as características do DNA de cada uma delas

Humoral immune response to Malassezia furfur in patients with pityriasis versicolor and seborrheic dermatitis.

Humoral immune responses against exoantigen components of oval, elliptic and round yeast forms of Malassezia furfur were analysed by ELISA and Western blotting assays, using sera from patients with pityriasis versicolor (PV), seborrheic dermatitis (SD) and healthy adults (HA), as control. Sera from patients with SD showed IgG anti-oval M. furfur titers ranging from 1/400 to 1/6400 showing geometric mean (GM) of 1/1472, higher than those obtained with sera from patients with PV (1/200 to 1/6400, GM = 1/1239). Both patient groups showed mean titres statistically superior (P < 0.05) than those obtained form HA (GM = 1/229). Similar data were also obtained with the elliptic and round antigens. However, the anti-oval IgG mean titers from patients' sera were much higher than those obtained with elliptic or round antigenic components (p < 0.05) Anti-M furfur IgM titers obtained from patient's sera with PV against all three exoantigens were statistically superior (p < 0.05) than HA group. Patients with SD showed IgM titers statistically superior (p < 0.05) only to oval yeasts of M. furfur. The IgA mean titers from patients' groups against the different morphological antigens were shown be slightly higher than those HA group. By Western blot, using rabbit anti-sera, the different antigenic components of M.furfur showed a close relationship mainly between oval and elliptic yeast cells antigens. The 70 kDa component of the M. furfur exoantigen of oval morphology was recognized by 84% of the PV patients' sera. On the other hand, SD patients' sera recognized 3 principal components of 70 kDa (100%), 65 kDa (67%) and 84 kDa (53%). These components may be considered immunological markers for PV and SD. Twenty-five percent of HA sera recognized the components of 65, 70 and 94 kDa. This investigation shows that M. furfur antigens can sensitize the host, mainly the oval yeast form of M. furfur with a very important specific IgG response in patients with SD and PV.

Dermatitis seborreica en Parkinson: correlación clínico-micológica en 30 casos y revisión de la literatura / Seborrheic dermatitis in Parkinson didease: clinical-mycologic correlation in 30 cases and review of the literature

Se presenta un estudio comparativo para investigar dermatitis seborreica (DS) y frecuencia de Pityrisporum en 30 pacientes de Parkinson en tratamiento con L-dopa y 30 enfermos con otros padecimientos neurológicos. En los primeros se presentó la DS con mayor extensión (97 vs 90 por ciento). La presencia de Pityrosporum en Parkinson fue de 90 por ciento y en controles de 70 por ciento; la positividad estuvo independiente de las manifestaciones clínicas. La biopsia de superficie con cianoacrilato y tinción de PAS, mostró mayor utilidad para la investigación de este hongo, que la tinción de Gram y el examen con cinta adhesiva transparente