-
Revista Argentina de Microbiologia 2006The study of Malassezia has been postponed for many years due to its nutritional requirements and its morphological variability. Molecular biology methods led to a... (Comparative Study)
Comparative Study Review
The study of Malassezia has been postponed for many years due to its nutritional requirements and its morphological variability. Molecular biology methods led to a taxonomic revision of this genus and to a new interest for its clinical importance. Nowadays, 11 Malassezia species are known, 10 are lipophilic, having similar morphological, physiological and biochemical characteristics, therefore, conventional techniques are not useful to differentiating them. Molecular methods are an accurate tool in the identification and they lead to a better knowledge of the ecology and epidemiology of this genus. Noteworthy antifungal susceptibility variations have been observed in some species, although there is not a standard method for these yeasts. There are few data about their biochemical characteristics, and the enzymes they produce might be important virulence factors, favouring host tissue invasion. Malassezia has been recognised as a member of the normal human and animal skin. Its implication in pathologic processes, including skin diseases to systemic infections, is the main issue in current investigations in order to determine the real pathogenic role of these yeasts.
Topics: Animals; Antifungal Agents; Culture Media; Dermatomycoses; Drug Resistance, Fungal; Energy Metabolism; Folliculitis; Fungal Proteins; Humans; Lipid Metabolism; Malassezia; Mycology; Skin; Species Specificity; Tinea Versicolor
PubMed: 16784135
DOI: No ID Found -
Journal de Mycologie Medicale Jun 2014Pityriasis versicolor is a common superficial mycotic disease of the skin which is caused by different species of Malassezia genus. The aim of this study was to...
Pityriasis versicolor is a common superficial mycotic disease of the skin which is caused by different species of Malassezia genus. The aim of this study was to contribute to the knowledge of the aetiology of pityriasis versicolor (PV) with a mycological study made according to the new species and additionally, the success of the different sampling techniques, duration and recurrence history of the disease, distribution of infecting strains according to the affected body sites were also investigated. In total, 146 patients with pityriasis versicolor were included in this study. Fungal elements could only be visualized by potassium hydroxide examination in 36.4% of the samples. Specimens obtained by scraping skin surface by a sterile scalpel and/or sterile sticky plaster (OpSite) were inoculated in plates containing modified Dixon's medium. Out of 146 samples, 109 (74.7%) yielded a growth which was considered to be Malassezia spp. in culture. Species level identification of suspicious Malassezia yeasts was made according to their macroscopic and microscopic features, and their physiological characteristics. Among the identified species, Malassezia globosa (65.1%) was the most commonly isolated species, followed by Malassezia obtusa (17.4%). However, four Malassezia isolates could not be identified at species level with conventional methods. While most of the patients suffered their first episode of pityriasis versicolor (76%), back of the trunk was the mostly affected body site (39%). In conclusion, Malassezia globosa was found to be the predominant species in pityriasis versicolor patients in our region, and culture of the specimen is necessary for the epidemiologic purposes.
Topics: Adolescent; Adult; Child; Female; Humans; Malassezia; Male; Microbial Sensitivity Tests; Middle Aged; Mycological Typing Techniques; Tinea Versicolor; Turkey; Young Adult
PubMed: 24746716
DOI: 10.1016/j.mycmed.2014.02.001 -
Veterinary Microbiology Jul 2018The yeast Malassezia pachydermatis is a component of the microbiota of dogs and cats, however it can cause otitis and seborrheic dermatitis in these animals. The...
The yeast Malassezia pachydermatis is a component of the microbiota of dogs and cats, however it can cause otitis and seborrheic dermatitis in these animals. The objective of this study was to determine the antifungal susceptibility, and evaluate virulence and pathogenicity of 25 M. pachydermatis strains from animals. Susceptibility to ketoconazole, fluconazole, itraconazole, voriconazole, terbinafine, and amphotericin B was evaluated by broth microdilution assay. In addition, biofilm-forming ability, protease, phospholipase, hemolysin and melanin production and adhesion to epithelial cells by this yeast species were assessed. Finally, strain pathogenicity was investigated using the nematode Caenorhabditis elegans. Concerning the planktonic susceptibility, minimum inhibitory concentrations varied from <0.03 to>64 μg/mL for azole derivatives, 1 to >16 μg/mL for amphotericin B and 0.03 to 0.25 μg/mL for terbinafine. All strains were classified as strong biofilm producers, and ketoconazole, fluconazole and amphotericin B presented the best inhibitory effect against mature biofilms. All fungal isolates produced proteases, whereas 14/25 strains were positive for phospholipase production. Hemolytic activity was not observed and 18/25 strains showed dark pigmentation in the presence of L-DOPA. Regarding adhesion to epithelial cells, a low adhesion rate was observed in 10/12 evaluated strains. C. elegans mortality rate reached 95.9% after 96 h of exposure of the worms to M. pachydermatis. This yeast species produces important virulence factors and presents high pathogenicity, corroborating its clinical importance.
Topics: Animals; Antifungal Agents; Bacterial Adhesion; Biofilms; Caenorhabditis elegans; Cat Diseases; Cats; Dermatomycoses; Dog Diseases; Dogs; Epithelial Cells; Fluconazole; Foxes; Itraconazole; Ketoconazole; Malassezia; Microbial Sensitivity Tests; Peptide Hydrolases; Phospholipases; Virulence
PubMed: 29885800
DOI: 10.1016/j.vetmic.2018.05.003 -
Mycoses Dec 2017Previous studies have evaluated the action of gentamicin against Malassezia pachydermatis. The aim of this study was to evaluate in vitro susceptibility of...
Previous studies have evaluated the action of gentamicin against Malassezia pachydermatis. The aim of this study was to evaluate in vitro susceptibility of M. pachydermatis to the aminoglycosides- gentamicin, tobramycin, netilmicin and framycetin. The minimum inhibitory concentration (MIC) of gentamicin was determined following methods M27-A3 microdilution and Etest . The Etest was used to determine the minimum inhibitory concentration (MIC) of the tobramycin and netilmicin. The Kirby-Bauer test was used to determine the antibiotic susceptibility to the framycetin. The MIC50 and MIC90 were 8.12 μg/mL and 32.5 μg/mL by microdilution method for gentamicin. The MIC50, determined by the Etest , was 8 μg/mL for gentamicin and netilmicin and 64 μg/mL for tobramycin. The MIC90 was 16 and 32 μg/mL for gentamicin and netilmicin respectively. The MIC90 was outside of the detectable limits for tobramycin. To framycetin, 28 strains (40%) of the 70 M. pachydermatis isolates tested showed a diameter of 22 mm, 22 strains (31.42%) showed a diameter of 20 mm, 16 strains showed a diameter of ≤ 18 mm, and only 5.71% of the isolates showed a diameter of ≥ 22 mm. This study provides evidence of high in vitro activity of the aminoglycosides-gentamicin, tobramycin, netilmicin and framycetin against M. pachydermatis. For gentamicin Etest showed similar values of MIC50 y MIC90 that the obtained by microdilution method. We considered Etest method could be a good method for these calculations with aminoglycosides.
Topics: Amikacin; Aminoglycosides; Antifungal Agents; Gentamicins; Malassezia; Microbial Sensitivity Tests; Netilmicin; Tobramycin
PubMed: 28925032
DOI: 10.1111/myc.12665 -
Nihon Ishinkin Gakkai Zasshi = Japanese... 1999The genus Malassezia is composed of lipophilic basidiomycetous yeasts which were recently shown to consist of seven species, one lipid-independent species, M.... (Review)
Review
The genus Malassezia is composed of lipophilic basidiomycetous yeasts which were recently shown to consist of seven species, one lipid-independent species, M. pachydermatis and six lipid-dependent species, M. furfur, M. sympodialis, M. globosa, M. obtusa, M. restricta and M. slooffiae. Based on this classification, we will be able to analyze pathogenicity or relationship between Malassezia-related diseases and each species.
Topics: Malassezia
PubMed: 10234074
DOI: 10.3314/jjmm.40.59 -
Veterinary Dermatology Oct 2007An adult male Pygmy goat with a history of losing hair and declining body condition was euthanized, and a complete diagnostic work-up was performed. The animal showed...
An adult male Pygmy goat with a history of losing hair and declining body condition was euthanized, and a complete diagnostic work-up was performed. The animal showed diffuse alopecia on the dorsal and lateral sides of thorax and abdomen, proximal legs, neck and face. Histology revealed diffuse orthokeratotic hyperkeratosis, epidermal hyperplasia and perivascular dermatitis. Broad-based budding yeasts and hyphae were visible in the keratin layer. Malassezia slooffiae was identified in the skin by polymerase chain reaction amplification of part of the large subunit rRNA gene using broad-range fungal primers and DNA sequencing. This is the first report of M. slooffiae-associated dermatitis in goats.
Topics: Animals; DNA Primers; DNA, Fungal; Dermatomycoses; Diagnosis, Differential; Goat Diseases; Goats; Malassezia; Male; Polymerase Chain Reaction
PubMed: 17845623
DOI: 10.1111/j.1365-3164.2007.00606.x -
La Tunisie Medicale Feb 2010Pityriasis versicolor is caused by Malassezia sp. It is a common worldwide mycosis. Recently, eleven species are known of the Malassezia genus, and are identified in...
BACKGROUND
Pityriasis versicolor is caused by Malassezia sp. It is a common worldwide mycosis. Recently, eleven species are known of the Malassezia genus, and are identified in vitro by their morphological characteristics, biochemical tests and by molecular biology. The aim of this study is the identification of Malassezia species from Tunisian patients with pityriasis versicolor.
METHODS
Specimens were taken from 58 patients with pityriasis versicolor. All samples were both inoculated in Sabouraud dextrose agar and Sabouraud agar overlaid with olive oil. Malassezia species were identified by morphological and physiological methods: macroscopy, microscopy, catalase, urease and lipid assimilation tests.
RESULTS
We have isolated five Malassezia species: Malassezia globosa being isolated in 76.2% of patients, followed by Malassezia furfur (9.55%), Malassezia sympodialis (4.75%), Malassezia slooffiae (4.75%) and Malassezia pachydermaties (4.75%).
CONCLUSION
In our study Malassezia globosa presents the main species implicated in the pathogenicity of pityriasis versicolor and Malassezia furfur as the second agent of importance.
Topics: Cross-Sectional Studies; Humans; Malassezia; Tinea Versicolor
PubMed: 20415164
DOI: No ID Found -
Nihon Ishinkin Gakkai Zasshi = Japanese... 2007
Review
Topics: Antifungal Agents; DNA, Fungal; DNA, Ribosomal; Dermatomycoses; Drug Resistance, Fungal; Humans; Malassezia; Phylogeny
PubMed: 18161220
DOI: No ID Found -
Parassitologia Jun 2008Lipophilic yeasts are being considered as major opportunistic pathogens for a very long time. Most of the yeasts show an absolute requirement for long fatty acid chains... (Review)
Review
Lipophilic yeasts are being considered as major opportunistic pathogens for a very long time. Most of the yeasts show an absolute requirement for long fatty acid chains and specific procedures are required for their isolation, conservation and identification. For that reason, the history of the nomenclature used for the Malassezia genus is quite complex. Before 1996, only 3 species were recognized: Malassezia furfur, M. pachydermatis and M. sympodialis. To date, the genus is composed of one non lipid-dependent species (M. pachydermatis) and 12 lipid-dependent species. No doubt that additional new taxa will be described in close future. Very recently the genome and secretory proteome of two Malassezia species was described. This analysis demonstrated the presence of multiple secreted lipases to aid in harvesting host lipids. It also revealed the presence of mating-type genes, providing an indication that Malassezia yeasts may be capable of sex.
Topics: Animals; DNA, Fungal; Dermatomycoses; Fatty Acids; Fungal Proteins; Genome, Fungal; Humans; Lipase; Malassezia; Proteome; Skin; Species Specificity; Terminology as Topic
PubMed: 18693563
DOI: No ID Found -
Mycoses Jul 2020For fatty acid esters of monohydric alcohols, cleavage by exo-enzymes of Malassezia (M.) spp. and release of fatty acids with antimicrobial activity have been shown...
BACKGROUND
For fatty acid esters of monohydric alcohols, cleavage by exo-enzymes of Malassezia (M.) spp. and release of fatty acids with antimicrobial activity have been shown recently. On skin surface, this selective activation of antimicrobial activity might result in a 'self-kill' targeted locally at the site with the highest M. density.
OBJECTIVES
As for the disadvantage of strong odour, use of these esters for topical therapy is limited to low concentrations. Therefore, cleavage was also tested for monoesters of octanoic and undec-10-enoic acid with the bihydric alcohol propane-1,3-diol or the trihydric glycerol.
METHODS
In an agar dilution test, the minimal inhibitory concentrations of these compounds were determined for M. furfur, M. globosa, M. sympodialis and M. restricta, respectively. GC analysis of parent compounds and liberated fatty acids was used to reveal ester cleavage.
RESULTS
Ester cleavage started immediately. MICs for the test compounds ranged between ~1000-8000 ppm after 14 days of incubation. 1,3-propanediol esters, especially 3-hydroxypropyl octanoate and 3-hydroxypropyl undecylenate were most effective, binary combinations exerted synergistic effects.
CONCLUSIONS
The new substances are advantageous in terms of odour and substantivity and have also beneficial skin caring properties if not hydrolysed by M. spp. As a different panel of hydrolases of each single M. species is responsible for variation in efficacy among the test substances, tailored products to treat preferentially single species or blends with a broader effectivity can be designed. In vivo verification will be the next step for the successful development of this new therapeutical concept for M.-associated diseases.
Topics: Antifungal Agents; Esters; Fatty Acids; Malassezia; Microbial Sensitivity Tests
PubMed: 32306427
DOI: 10.1111/myc.13093