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At least 19 recordsLinked to original sources
PubMed2002

Differentiation of Malassezia furfur and Malassezia sympodialis by glycine utilization.

The genus Malassezia has been revised to include six lipophilic species and one nonlipophilic species. These Malassezia species have been investigated to differentiate their morphological and physiological characteristics. However, assimilation of amino acids as a nitrogen source by these species was not well elucidated. In the present study, isolates of Malassezia species were examined with a glycine medium (containing 7-266 mmol glycine, 7.4 mmol KH(2)PO(4), 4.1 mmol MgSO(4)7H(2)O, 29.6 mmol thiamine, 0.5% Tween-80 and 2% agar) and a modified Dixon glycine medium (0.6% peptone, 3.6% malt extract, 2% ox-bile, 1% Tween-40, 0.2% glycerol, 0.2% oleic acid, 7 mmol glycine and 2% agar). All M. furfur isolates developed on the glycine medium, assimilating glycine at concentrations of at least 7 mmol l(-1). However, the other six Malassezia species were unable to grow on the glycine medium. Also, many colonies of M. furfur grew rapidly, within 2-3 days on the modified Dixon glycine medium, although the other six species showed slow and poor development. From these results, it was suggested that M. furfur might be able to utilize glycine as a single nitrogen source, which the other Malassezia species could not. Therefore, glycine medium was recommended for the differentiation of M. furfur from other species of Malassezia.

Animals↗
PubMed2006

In vitro antifungal efficacy of ciclopirox olamine alone and associated with zinc pyrithione compared to ketoconazole against Malassezia globosa and Malassezia restricta reference strains.

The aim of this study was to determine the in vitro fungicidal and growth inhibitory activity of ciclopirox olamine alone (1% and 1.5%) or in association with 1% zinc pyrithione compared to 2% ketoconazole, against Malassezia species particularly involved in the pathogenesis of seborrheic dermatitis. Experiments were performed on Malassezia globosa IP 2387.96 and M. restricta IP 2392.96 strains. Growth inhibitory activity of the active compounds in solution was evaluated by measuring minimal inhibitory concentrations using a broth micro-method and their fungicidal activity by a filtration method after contact times between solutions and yeasts ranging from 3-5 to 30 min. Concerning the determination of minimal inhibitory concentration of ciclopirox olamine/zinc pyrithione, it revealed the marked synergistic inhibitory effect of the association, leading to a higher efficacy compared to ketoconazole. As to the fungicidal activity of ciclopirox olamine, it significantly increased with the contact time. After 15-30 min of contact between 1.5% ciclopirox olamine and Malassezia strains, a 2-log reduction of Malassezia counts was observed. The 1.5% ciclopirox olamine/1% zinc pyrithione association was characterized by a steady fungicidal efficacy whereas the 2% ketoconazole solution did not express any fungicidal effect. In conclusion, this study demonstrates the in vitro inhibitory and fungicidal efficacy of the ciclopirox olamine/zinc pyrithione association against Malassezia species and underscores its potential interest in the treatment of seborrheic dermatitis.

Antifungal Agents↗
PubMed2004

Elevated levels of IgG and IgG4 to Malassezia allergens in atopic eczema patients with IgE reactivity to Malassezia.

BACKGROUND: The opportunistic yeast Malassezia is considered to be one of the factors that can contribute to atopic eczema (AE). Elevated serum IgE levels, T-cell proliferation and positive skin prick test (SPT) and atopy patch test (APT) reactions to Malassezia are found among AE patients. METHODS: Sera from 127 AE patients, 14 patients with seborrheic dermatitis (SD) and 33 healthy controls were investigated for IgE and IgG4 to M. sympodialis extract and four recombinant Malassezia allergens; rMala s 1, rMala s 5, rMala s 6, and rMala s 9. In addition, IgG to the recombinant allergens was analyzed. The IgG and IgG4 levels were compared to IgE levels and in vivo reactions (SPT and APT) to Malassezia. RESULTS: AE patients with serum IgE levels >0.35 kU/l to M. sympodialis extract had significantly higher IgG4 levels to M. sympodialis extract than AE patients without detectable serum IgE to M. sympodialis extract, SD patients and healthy controls. Among the AE patients with and without detectable serum IgE to M. sympodialis extract, respectively, there were no differences in IgG4 levels between patients with positive or negative in vivo reactions to M. sympodialis extract. IgG4 to the rMala s allergens was almost exclusively found among patients with IgE to the same allergen. Within the four tested rMala s allergens, most IgG4 reactions were found to rMala s 6, an allergen with homology to cyclophilin. CONCLUSIONS: Elevated serum IgG4 to M. sympodialis extract accompanies elevated serum IgE to the extract. This is further confirmed by the association between IgG/IgG4 and IgE to recombinant Malassezia allergens.

Adolescent↗
PubMed2003

[Atopic dermatitis and Malassezia species: a study of antigenic components of Malassezia species for immunoglobulin E of patients with atopic dermatitis].

Antigenic components extracted by treatment with beta-mercaptoethanol from M. furfur, M. globosa, M. restricta, M. slooffiae, and M. sympodialis were studied for immunoglobulin E antibodies in sera of patients with atopic dermatitis. CBB staining and lectin blots of the extracts showed that each Malassezia species contained species-dependent components at the protein level. In a Western blot with the 2-ME extracts,IgE antibodies against the Malassezia species were found in sera of 83% (for M. globosa), 74% (for M. sympodialis), 65% (for M. furfur), 56% (for M. restricta) and 50% (for M. slooffiae) of the AD patients. In the Western blot inhibition test, the 2-ME extract of M. globosa partially inhibited the reaction of the antigenic components of other Malassezia species with the patients IgE antibodies. These results indicated that Malassezia species contained both species-specific and common antigenic components at the IgE antibody level. A major component of M. globosa was isolated from the 2-ME extract of this fungus by ion-exchange column chromatography and was referred to as Malg46b. Dot blot with the Malg46b containing fraction immunologically reacted with 69% of the sera of the patients, and with 83% of the sera of those who were positive for IgE antibodies to the 2-ME extract of M. globosa in Western blot. The intensities generated for each dot correlated well with the total intensities generated for the 2-ME extract of M. globosa in Western blot (r=0.763) The polyclonal antibody to Malg46b reacted strongly only with the 2-ME extract of M. globosa and reacted slightly with M. restricta. These results indicate that a glycoprotein, Malg46b of M. globosa, is dominantly expressed in this fungus and is a possible major antigen for IgE antibodies in patients with AD.

Antibodies, Fungal↗
PubMed1998

Different utilization of neutral lipids by Malassezia furfur and Malassezia sympodialis.

In recent years, the genus Malassezia has been expanded based on molecular data; in addition to M. furfur and M. pachydermatis, five new species (M. sympodialis, M. globosa, M. obtusa, M. restricta, M. slooffiae) have been described. Apart from their lipid dependence, little is known about the metabolism and nutritional requirements of these new species. Defined inocula of Malassezia reference strains were cultured on selective agar for pathogenic fungi which was overlaid with olive oil. Samples of the olive oil overlay were taken at regular intervals and the lipid fractions were analysed by high performance thin layer chromatography. Depending on the time of incubation and the number of cells, M. sympodialis and the other recently described species produced a significant increase in free fatty acids. In addition, a band of an apolar substance was identified as a mixture of fatty acid ethyl esters. While showing growth, strains of M. furfur produced only small amounts of ethyl esters and free fatty acids. The growth kinetics of M. furfur and M. sympodialis were also different: for M. sympodialis, a clear lag phase was observed, possibly indicating the necessity of extracellular hydrolysis of the triglycerides. The significance of the synthesis of ethyl esters could not be clarified. For routine differentiation, this metabolic difference is only of limited usefulness because slight contamination of M. furfur strains with other lipophilic Malassezia species may lead to misinterpretation due to the high metabolic activity. These metabolic differences might be important in the pathogenesis of Malassezia infections.

Agar↗
PubMed2001

Epidermal dysplasia and Malassezia infection in two West Highland White Terrier siblings: an inherited skin disorder or reaction to severe Malassezia infection?

Two 9-month-old West Highland White Terrier siblings were referred to our clinic with pruritus, alopecia and lichenification. Cytological examination of Scotch tape strippings revealed Malassezia organisms and cocci. Skin biopsy specimens showed epidermal dysplasia. Treatment included bathing with a 2% miconazole/chlorhexidine-containing shampoo, orally administered ketoconazole (5 mg kg-1, every 12 h) and cloxacillin (25 mg kg-1 every 8 h). Six weeks later, the dermal infection had resolved and there was hair regrowth. However, the dogs were still moderately pruritic. Intradermal allergy testing was positive for house dust mites, storage mites and Malassezia. Immunotherapy was initiated, and treatment with ketoconazole and cloxacillin was stopped. Skin biopsies, which were performed in both dogs 4 months after the first presentation, revealed mild superficial perivascular dermatitis. The remaining mild facial pruritus was easily controlled with topical treatment. These two cases indicate that epidermal dysplasia might be an inflammatory or hypersensitivity reaction to the Malassezia infection or a result of excessive self-trauma, rather than a congenital keratinization disorder.

Animals↗
PubMed2002

Identification of major allergens of Malassezia pachydermatis in dogs with atopic dermatitis and Malassezia overgrowth.

We have previously shown that both atopic and normal dogs generate an IgG response to antigens of Malassezia pachydermatis. The aim of this study was to compare IgE responses to separated proteins of M. pachydermatis in 28 atopic dogs with Malassezia dermatitis and 22 clinically normal dogs using Western immunoblotting. Six different detection systems were evaluated in order to assess sensitivity and eliminate nonspecific binding and cross-reactivity. The protocol yielding the best results utilized a monoclonal mouse antidog IgE, an alkaline phosphatase conjugated goat antimouse IgG which had been passed through a canine IgG column 3 times, a chemiluminescent substrate and a digital imaging system. Proteins of 45, 52, 56 and 63 kDa were recognized by more than 50% of the atopic dog sera and thus represented major allergens. Only a minority of normal dogs showed faint IgE binding to these proteins. The results indicate that the majority of atopic dogs with Malassezia dermatitis have a greater IgE response than normal dogs, suggesting an IgE-mediated immune response may be clinically important in the pathogenesis of the disease.

Allergens↗
PubMed2006

Patch test responses to Malassezia pachydermatis in healthy basset hounds and in basset hounds with Malassezia dermatitis.

The effects of the patch test application of Malassezia pachydermatis extracts were evaluated in seven healthy basset hounds and in seven basset hounds with Malassezia dermatitis. Antigens (4 and 0.4 mg/ml) and saline controls were applied for 48 h using filter paper discs in Finn chambers. One healthy basset hound and five affected hounds showed positive patch test reactivity to the yeast antigens. Positive patch test reactions were characterized histologically by mild epidermal hyperplasia and mild to moderate perivascular, periadnexal and interstitial infiltrates of neutrophils and CD3+ lymphocytes. Immediate intradermal test reactivity to M. pachydermatis antigens was seen in one healthy and one affected hound, whereas delayed intradermal test reactivity was seen in six healthy hounds and five affected hounds. This study indicates that patch test reactivity to M. pachydermatis antigen may occur in healthy basset hounds, and in contrast to delayed intradermal test reactivity, is more frequent in basset hounds with Malassezia dermatitis.

Allergens↗
PubMed2002

Intradermal test reactivity to Malassezia pachydermatis in healthy basset hounds and basset hounds with Malassezia dermatitis.

Nineteen healthy beagles, eight healthy basset hounds and 17 basset hounds with Malassezia dermatitis were tested intradermally with two extracts of M pachydermatis. One healthy beagle and two affected basset hounds showed wheal and flare reactions 15 minutes after the injection. Delayed reactions, consisting of erythematous macules and plaques, were commonly observed 24 hours after the injection in both the healthy and affected basset hounds, but occurred infrequently in the beagles. At 24 hours the diameters of the lesions in the healthy and affected basset hounds were significantly (P<0.01) greater than those in the healthy beagles, but the diameters in the healthy and affected basset hounds did not vary significantly. Delayed reactions in six of the basset hounds with Malassezia dermatitis were characterised histologically by superficial perivascular and periadnexal infiltrates of neutrophils and lymphocytes.

Animals↗
PubMed1998

Humoral and cell-mediated responses to Malassezia pachydermatis in healthy dogs and dogs with Malassezia dermatitis.

The in vitro proliferative responses of peripheral blood mononuclear cells from seven healthy basset hounds exposed to Malassezia pachydermatis antigen (500 micrograms/ml) exceeded (P < 0.05) those of seborrhoeic basset hounds with high populations of M pachydermatis and eight Irish setters with gluten-sensitive enteropathy. The stimulation indices in the latter two groups and in eight healthy beagles were comparable. The stimulation indices of the four groups after exposure to phytohaemaglutinin did not differ significantly. The serum titres of M pachydermatis-specific IgG and IgA measured by enzyme-linked immunosorbent assays (ELISA) in 21 seborrhoeic basset hounds and 11 affected dogs of various breeds exceeded those of 14 healthy basset hounds and eight healthy beagles (P < 0.01 for IgG, P < 0.05 for IgA). Total serum IgA concentrations measured by ELISA in the affected dogs were not lower than those of healthy dogs.

Animals↗
PubMed1993

The distribution of Malassezia furfur and Malassezia pachydermatis on normal human skin.

Clinically normal skin of 200 volunteers, age range 20-30 years, were studied. Skin samples were taken by swabbing ten different sites and examined for the presence of Malassezia furfur and Malessezia pachydermatis by culture. All of the subjects studied harbored M. furfur at every site tested, and had high counts on the head region and upper trunk. The strains isolated could be divided on the basis of culture characteristics into three distinct groups. Only 12% of the subjects carried M. pachydermatis with very low counts at sites on the head and palm.

Adult↗
PubMed2002

Immunoglobulin G responses to Malassezia pachydermatis in healthy dogs and dogs with Malassezia dermatitis.

Serum immunoglobulin G (IgG) responses of healthy dogs and dogs with Malasseziapachydermatis dermatitis were compared by Western immunoblotting. M pachydermatis CBS 1879 was disrupted mechanically and its proteins were separated and blotted on to nitrocellulose membranes before being incubated with sera from eight healthy beagles, eight Irish setters with gluten-sensitive enteropathy, 15 healthy basset hounds, and 30 dogs with Mpachydermatis-associated dermatitis, 20 of which were basset hounds. The mean (se) numbers of bands of immunoreactivity observed in the seborrhoeic basset hounds (10.7 [0.4]) and affected mixed-breed dogs (9.4 [0.9]) were significantly greater than in the beagles (3-0 [1.0]), Irish setters (5.5 [1.1]) and healthy basset hounds (5.6 [0.7]). The number of bands identified was correlated (r(s) = 0.76, P < 0.001) with the anti-M pachydermatis IgG values measured by ELISA in a previous study. Most of the dogs were immunoreactive towards the 132, 66 and 50 to 54 kDa proteins and the affected dogs were also usually reactive towards the 219, 110, 71 and 42 kDa proteins.

Animals↗
PubMed2004

[Application of methylene blue staining in detection of Malassezia].

OBJECTIVE: To assess the value of methylene blue and parker ink staining in the detection of Malassezia. METHODS: Detecting Malassezia in three dermatoses samples (pityriasis versicolor, Malassezia folliculitis and dandruff) stained by methylene blue (3 g/L) or parker ink. Comparing the effectiveness and the positive rates of Malassezia detection between the two staining methods. Staining Malassezia and Candida and comparing the specificity of the two staining methods in staining Malassezia. RESULTS: Dark blue hyphae and spores were observed in smears stained by methylene blue, and light blue hyphae and spores were observed in smears stained by parker ink. Hyphae and spores were easy to identify on the background. The positive rates of methylene blue and parker ink for detecting Malassezia in the three dermatoses were 96% and 94% respectively. There was no significant difference between the two dye liquors in the positive rate for deterting Malassezia. Both Malassezia and Candida could be stained by methylene blue; nevertheless, only Malassezia could be stained by parker ink. CONCLUSION: Both methylene blue and parker ink staining can be used to detect Malassezia, but parker ink has higher specificity in Malassezia staining.

Dermatomycoses↗
PubMed2001

The effects of Malassezia yeasts on cytokine production by human keratinocytes.

Yeasts of Malassezia, members of the microbiologic flora of the skin, cause pityriasis versicolor and have also been implicated in the pathogenesis of other superficial dermatoses; the most important ones are seborrheic dermatitis, folliculitis, and atopic dermatitis. The mechanisms by which the yeasts cause these dermatoseş however, are not yet clear, and there have been no studies on the interaction between fungi and keratinocytes, especially the effects of fungi on the production of cytokines by human keratinocytes. Recently, the genus Malassezia has been expanded to seven species based on molecular data. In this study, we estimated the effects of Malassezia yeasts on cytokine (interleukins 1beta, 6, and 8, monocyte chemotactic protein-1, and tumor necrosis factor-alpha) production by human keratinocytes in order to examine whether the pathogenicity of the respective Malassezia yeasts is different from each other and to elucidate the mechanism by which Malassezia yeasts cause the dermatoses with different clinical and pathologic manifestations. Variable levels of interleukin 6 and 8, and tumor necrosis factor-alpha in the supernatants in response to Malassezia yeasts (except M. furfur) increased from 1 to 24 h co-culture, but the monocyte chemotactic protein-1 was undetectable. Furthermore, cytokine levels in the supernatants were undetectable 1-24 h after the keratinocytes were harvested with only supernatants of Malassezia. These results indicate that Malassezia stimulates cytokine production by keratinocytes, the cytokine production needs the presence of Malassezia, and there are differences in ability to induce cytokine production by human keratinocytes among Malassezia yeasts. These differences may reflect the different inflammatory responses in Malassezia-associated dermatoses, resulting in different clinical and pathologic manifestations.

Cell Survival↗
PubMed2005

Three etiologic facets of dandruff and seborrheic dermatitis: Malassezia fungi, sebaceous lipids, and individual sensitivity.

Application of new molecular and biochemical tools has greatly increased our understanding of the organisms, mechanisms, and treatments of dandruff and seborrheic dermatitis. Dandruff results from at least three etiologic factors: Malassezia fungi, sebaceous secretions, and individual sensitivity. While Malassezia (formerly P. ovale) has long been a suspected cause, implicated by its presence on skin and lipophylic nature, lack of correlation between Malassezia number and the presence and severity of dandruff has remained perplexing. We have previously identified the Malassezia species correlating to dandruff and seborrheic dermatitis. In this report, we show that dandruff is mediated by Malassezia metabolites, specifically irritating free fatty acids released from sebaceous triglycerides. Investigation of the toxic Malassezia free fatty acid metabolites (represented by oleic acid) reveals the component of individual susceptibility. Malassezia metabolism results in increased levels of scalp free fatty acids. Of the three etiologic factors implicated in dandruff, Malassezia, sebaceous triglycerides, and individual susceptibility, Malassezia are the easiest to control. Pyrithione zinc kills Malassezia and all other fungi, and is highly effective against the Malassezia species actually found on scalp. Reduction in fungi reduces free fatty acids, thereby reducing scalp flaking and itch.

Case-Control Studies↗
PubMed2005

Malassezia and Candida colonisation on glans penis of circumcised men.

The Malassezia yeast are members of the normal human cutaneous flora in adults. They also are reported as part of the microflora of the male genital region in mostly uncircumcised males. It has been reported that Malassezia sympodialis and Malassezia globosa are the most frequent yeast belonging to the resident microflora of the penis as in other human skin areas. The aim was to evaluate the prevalence of Malassezia and Candida yeast colonisation on the glans penis of circumcised males. Impression preparations were made on modified Dixon agar. The isolates were identified by morphological and physiological characteristics. A total of 245 circumcised males were included in the study. Of the 245 patients examined, 55 (22.4%) were found to have a mycologically proven yeast fungi on their glans penis. In 17 (30.9%) Malassezia, in 36 (65.5%) Candida, in one (1.8%) Malassezia and Candida, and in one (1.8%) Saccharomyces strains were detected. Malassezia furfur (66.7%) was the most common species among the lipophilic yeast, followed by Malassezia globosa (11.1%), Malassezia obtusa (11.1%) and Malassezia slooffiae (11.1%). Candida albicans was the most common non-lipophilic yeast (46.0%), that was isolated among the other yeast, followed by unidentified Candida strains (18.9%), Candida tropicalis (8.1%), Candida glabrata (8.1%), Candida parapsilosis (8.1%), Candida zeylanoides (5.4%), Candida guilliermondii (2.7%) and Saccharomyces cerevisiae (2.7%). The results of this study showed that Malassezia species were also colonised like Candida on the glans penis of circumcised males.

Adult↗