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Parassitologia Jun 2008A short review on Malassezia spp., completed with our experience, is made. The main epidemiological characteristics with particular regard to the diffusion in several... (Review)
Review
A short review on Malassezia spp., completed with our experience, is made. The main epidemiological characteristics with particular regard to the diffusion in several animal species, the characteristics of skin colonization (in particular of the dog) and the distribution of the different Malassezia spp. in some hosts are discussed. Lastly the main phenotypic and genotypic characteristics, referred to M. pachydermatis especially, were described, showing their high variability and differentiation.
Topics: Animals; Animals, Domestic; DNA, Fungal; Dermatomycoses; Female; Genetic Variation; Humans; Malassezia; Male; Mycological Typing Techniques; Random Amplified Polymorphic DNA Technique; Species Specificity
PubMed: 18693562
DOI: No ID Found -
Actas Dermo-sifiliograficas Dec 2008Although pityriasis versicolor is the only human disease for which Malassezia yeasts have been fully established as pathogens, it is still not clear which species are... (Comparative Study)
Comparative Study Review
Although pityriasis versicolor is the only human disease for which Malassezia yeasts have been fully established as pathogens, it is still not clear which species are implicated. Most studies carried out in recent years support our hypothesis - proposed in 1999 - that Malassezia globosa is the predominant species in pityriasis versicolor lesions, at least in temperate climates. Confirmation of this hypothesis could help us understand the conditions, as yet unclear, that induce transformation of this yeast from the saprophytic form present in healthy skin to the parasitic form, characterized by the formation of pseudomycelium, and could also guide therapy. In addition, isolation of another species, Malassezia furfur, which seems to be predominant in the tropics, raises the possibility of a second etiologic agent confined to certain areas, as occurs with some other human mycoses.
Topics: Adult; Animal Diseases; Animals; Climate; Humans; Malassezia; Models, Biological; Mycelium; Skin; Species Specificity; Tinea Versicolor; Tropical Climate
PubMed: 19091214
DOI: No ID Found -
Revista Iberoamericana de Micologia 2016All the currently recognized Malassezia species have been isolated from mammals. However, only a few of them have been isolated from birds. In fact, birds have been less...
BACKGROUND
All the currently recognized Malassezia species have been isolated from mammals. However, only a few of them have been isolated from birds. In fact, birds have been less frequently studied as carriers of Malassezia yeasts than mammals.
AIM
In this study we describe two new taxa, Malassezia brasiliensis sp. nov. and Malassezia psittaci sp. nov.
METHODS
The isolates studied in this publication were isolated from pet parrots from Brazil. They were characterized using the current morphological and physiological identification scheme. DNA sequencing and analysis of the D1/D2 regions of the 26S rRNA gene, the ITS-5.8S rRNA gene sequences and the β-tubulin gene were also performed.
RESULTS
The strains proposed as new species did not completely fit the phenotypic profiles of any the described species. The validation of these new species was supported by analysis of the genes studied. The multilocus sequence analysis of the three loci provides robust support to delineate these species.
CONCLUSIONS
These studies confirm the separation of these two new species from the other species of the genus Malassezia, as well as the presence of lipid-dependent Malassezia yeasts on parrots.
Topics: Animals; Beak; Brazil; Culture Media; DNA, Fungal; Fungal Proteins; Genes, Fungal; Lipids; Malassezia; Parrots; Phylogeny; Ribotyping; Sequence Analysis, DNA; Species Specificity; Tubulin
PubMed: 27184440
DOI: 10.1016/j.riam.2016.03.003 -
Mycopathologia Apr 2019Malassezia yeasts are opportunistic pathogens associated with a number of skin diseases in animals and humans. The free fatty acids released through these organisms'...
Malassezia yeasts are opportunistic pathogens associated with a number of skin diseases in animals and humans. The free fatty acids released through these organisms' lipase and phospholipase activities trigger inflammation in the host; thus, these lipase and phospholipase activities are widely recognised as some of the most important factors in Malassezia pathogenesis. In this study, we sought to investigate and examine the relationship between these secreted hydrolytic activities and haemolytic activity in newly isolated Malassezia clinical strains. This characterisation was expected to elucidate pathogenicity of this fungus. We isolated 35 clinical strains of Malassezia spp.; the most frequently isolated species were M. sympodialis and M. furfur. Next, we analysed the hydrolytic activities of all of these clinical isolates; all of these strains (except for one M. dermatis isolate) showed detectable lipase and phospholipase activities against 4-nitrophenyl palmitate and L-α-phosphatidylcholine, dipalmitoyl, respectively. Most of the M. globosa isolates showed higher lipase activities than isolates of other Malassezia species. In terms of phospholipase activity, no significant difference was observed among species of Malassezia, although one isolate of M. globosa showed considerably higher phospholipase activity than the others. All tested strains also exhibited haemolytic activity, both as determined using 5% (v/v) sheep blood agar (halo assay) and by quantitative assay. Although all tested strains showed detectable haemolytic activity, we did not observe an apparent correlation between the secreted lipase and phospholipase activities and haemolytic activity. We infer that the haemolytic activities of Malassezia spp. are mediated by non-enzymatic factor(s) that are present in the secreted samples.
Topics: 1,2-Dipalmitoylphosphatidylcholine; Adult; Animals; Dermatomycoses; Hemolysis; Humans; Infant; Lipase; Malassezia; Palmitates; Phospholipases; Sheep; Young Adult
PubMed: 30919309
DOI: 10.1007/s11046-019-00330-1 -
Mycoses 1991Five strains of Malassezia pachydermatis isolated from small animals in Bratislava were subcultured, maintained under sterile paraffin oil and preserved in liquid...
Five strains of Malassezia pachydermatis isolated from small animals in Bratislava were subcultured, maintained under sterile paraffin oil and preserved in liquid nitrogen. Morphological and physiological characteristics as well as the analysis of long chain fatty acids of the cell mass were determined. The results showed that the maintenance in liquid nitrogen is the most satisfactory method of preservation of pure cultures of Malassezia pachydermatis.
Topics: Animals; Cat Diseases; Cats; Dog Diseases; Dogs; Malassezia; Pityriasis; Preservation, Biological
PubMed: 1803241
DOI: 10.1111/j.1439-0507.1991.tb00675.x -
Microbiology (Reading, England) Mar 2020is a lipophilic cutaneous commensal yeast and associated with various skin disorders. The yeast also causes bloodstream infection via intravascular catheters and can be...
is a lipophilic cutaneous commensal yeast and associated with various skin disorders. The yeast also causes bloodstream infection via intravascular catheters and can be detected even in human gut microbiota. Ambient pH is one of the major factors that affect the physiology and metabolism of several pathogenic microorganisms. Although dynamic changes of pH environment in different parts of the body is a great challenge for to confront, the role that ambient pH plays in is largely unknown. In this study, we investigated the impact of ambient pH on physiology and expression of lipases in grown under different pH conditions. The yeast was able to grow in media ranging from pH 4 to 10 without morphological alteration. Elevation in pH value enhanced the extracellular lipase activity but decreased that of intracellular lipase. The qPCR results revealed that a set of functional lipase genes, , were constitutively expressed regardless of pH conditions or exposure time. Based on the data, we conclude that the external pH plays a promotional role in the secretion of lipases but exerts less effect on transcription of the genes and morphology in .
Topics: Gene Expression; Genes, Fungal; Hydrogen-Ion Concentration; Lipase; Malassezia
PubMed: 31860440
DOI: 10.1099/mic.0.000879 -
Chinese Medical Journal Apr 2019
Topics: Humans; Hydrogen-Ion Concentration; Malassezia; Staphylococcus epidermidis
PubMed: 30897602
DOI: 10.1097/CM9.0000000000000152 -
Medical Mycology Journal 2011Most species of this genus are lipid-dependent yeasts, which colonize the seborrheic part of the skin, and they have been reported to be associated with pityriasis... (Review)
Review
Most species of this genus are lipid-dependent yeasts, which colonize the seborrheic part of the skin, and they have been reported to be associated with pityriasis versicolor, Malassezia folliculitis, seborrheic dermatitis, and atopic dermatitis. Malassezia have been re-classified into 7 species based on molecular biological analysis of nuclear ribosomal DNA/RNA and new Malassezia species were reported. As members of the genus Malassezia share similar morphological and biochemical characteristics, it was thought to be difficult to differentiate between them based on phenotypic features. While molecular biological techniques are the most reliable methods for identification of Malassezia, they are not available in most clinical laboratories. We studied ( i ) development of an efficient isolation media and culture based easy identification system, ( ii ) the incidence of atypical biochemical features in Malassezia species and propose a culture-based easy identification system for clinically important Malassezia species, M. globosa, M. restricta, and M. furfur.
Topics: Culture Media; Humans; Malassezia; Mycology
PubMed: 22123328
DOI: 10.3314/mmj.52.297 -
Diagnostic Microbiology and Infectious... Oct 2018The taxonomy of Malassezia species is evolving with introduction of molecular techniques, and difficulty is faced to identify the species by phenotypic methods. Among 15...
The taxonomy of Malassezia species is evolving with introduction of molecular techniques, and difficulty is faced to identify the species by phenotypic methods. Among 15 known Malassezia species, the present Bruker database could identify only 2 species. The present study was aimed to improve Matrix -assisted laser desorption ionization time-flight mass spectrometry (MALDI-TOF MS) based identification of Malassezia species. A total of 88 isolates (DNA sequencing confirmed) for database preparation and, for the validation of database, 190 isolates confirmed by polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) were used. The main spectrum profile dendrogram showed the sufficient discrimination between all the species by MALDI-TOF MS. The updated Malassezia database could identify 94.7% and 5.3% strains to the species and genus level, respectively. MALDI-TOF MS is a significantly reliable technique, and results were comparable with PCR-RFLP with kappa value 0.9. In conclusion, MALDI-TOF MS could be a possible alternative tool to other molecular methods for rapid and accurate identification of Malassezia species.
Topics: Cluster Analysis; Databases, Factual; Dermatomycoses; Humans; Malassezia; Polymerase Chain Reaction; Polymorphism, Restriction Fragment Length; Sequence Analysis, DNA; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
PubMed: 30025965
DOI: 10.1016/j.diagmicrobio.2018.05.015 -
Mycoses Jul 2019Malassezia yeasts produce bioactive indolic substances when grown on L-tryptophan agar. A panel of these substances was tested against commensal and opportunistic fungi,...
BACKGROUND
Malassezia yeasts produce bioactive indolic substances when grown on L-tryptophan agar. A panel of these substances was tested against commensal and opportunistic fungi, the Minimum Inhibitory Concentration (MIC) was determined and the potential for in loco antifungal activity on the skin was assessed.
MATERIALS AND METHODS
Eight indoles were included (malassezin, pityriacitrin, indirubin, indolo[3,2-b]carbazole, 6-formylindolo[3,2-b]carbazole, tryptanthrin, 6-hydroxymethylindolo[3,2-b]carbazole and 6-methylindolo[3,2-b]carbazole) and were tested against 40 fungal strains [yeasts: Malassezia spp.(N = 9); Cryptococcus spp.(N = 10); Candida spp.(N = 7); Yarrowia lipolytica(N = 1); Exophialla dermatitidis (N = 2); moulds: Aspergillus spp.(N = 7); Fusarium spp.(N = 2); Rhizopus oryzae(N = 2)]. The concentration of 5/8 of the tested indoles on diseased skin was calculated from published data. Kruskal-Wallis and Mann-Whitney U tests were employed for group susceptibility evaluation in 33 strains.
RESULTS
The MIC range was 0.125-32 μg/mL, and the median log MIC was four. Indirubin was the most potent antifungal agent and differed significantly from the others. The highest median MIC was found for FICZ. Malassezia with Candida strains were more susceptible compared to Cryptococcus and Aspergillus, and this inhibitory activity was predicted to be valid also on human skin.
CONCLUSIONS
Malassezia yeasts produce indolic species that inhibit an array of clinically significant yeasts and moulds.
Topics: Antifungal Agents; Culture Media; Fungi; Humans; Indoles; Malassezia; Microbial Sensitivity Tests
PubMed: 30636018
DOI: 10.1111/myc.12893