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Microbiology Spectrum Feb 2022Seborrheic dermatitis (SD) is a common, chronic, and relapsing skin disease. The roles of spp. in the pathogenesis of SD are still not clear due to the lack of direct...
Seborrheic dermatitis (SD) is a common, chronic, and relapsing skin disease. The roles of spp. in the pathogenesis of SD are still not clear due to the lack of direct evidence for the existence of hyphae within affected skin tissues. We set out to elucidate if mycelium contributes to the onset and development of SD and if mycelium is correlated with the clinical severity of SD patients. We detected hyphae in patients with SD using potassium hydroxide (KOH) and calcofluor white (CFW) staining. Fluorescent microscopy was performed for the analysis of fungal cell wall and morphological characteristics of under CFW staining. Culture growth in modified Dixon agar was used for DNA extraction and sequencing, and species were confirmed by a sequencing data BLAST search against the NCBI database. We demonstrated that hyphae were positively correlated with the clinical severity of SD patients (= 3.1738 × 10). All the patients responded well to antifungal treatment. There is no significant difference for species dominance across the variant groups. However, the exact molecular mechanisms of how spp. affect SD need to be further explored. The results show that spp. in the hyphal stage are restricted to SD patients compared with healthy controls, suggesting that the presence of hyphae contributes to the pathogenesis of SD. The results highlight the importance of the antifungal therapy for the future treatment of SD patients. Our results support the proposal that the hyphal form of could be one of the pathogenic factors that contribute to SD, which has been previously less well studied. This clinical observation paves the way for further investigations of the molecular mechanisms of hyphal pathogenicity in SD.
Topics: Adult; Antifungal Agents; Dermatitis, Seborrheic; Dermatomycoses; Female; Humans; Hyphae; Malassezia; Male; Middle Aged; Skin
PubMed: 35019692
DOI: 10.1128/spectrum.01169-21 -
Clinical Microbiology Reviews Jan 2012In the last 15 years, the genus Malassezia has been a topic of intense basic research on taxonomy, physiology, biochemistry, ecology, immunology, and metabolomics.... (Review)
Review
In the last 15 years, the genus Malassezia has been a topic of intense basic research on taxonomy, physiology, biochemistry, ecology, immunology, and metabolomics. Currently, the genus encompasses 14 species. The 1996 revision of the genus resulted in seven accepted taxa: M. furfur, M. pachydermatis, M. sympodialis, M. globosa, M. obtusa, M. restricta, and M. slooffiae. In the last decade, seven new taxa isolated from healthy and lesional human and animal skin have been accepted: M. dermatis, M. japonica, M. yamatoensis, M. nana, M. caprae, M. equina, and M. cuniculi. However, forthcoming multidisciplinary research is expected to show the etiopathological relationships between these new species and skin diseases. Hitherto, basic and clinical research has established etiological links between Malassezia yeasts, pityriasis versicolor, and sepsis of neonates and immunocompromised individuals. Their role in aggravating seborrheic dermatitis, dandruff, folliculitis, and onychomycosis, though often supported by histopathological evidence and favorable antifungal therapeutic outcomes, remains under investigation. A close association between skin and Malassezia IgE binding allergens in atopic eczema has been shown, while laboratory data support a role in psoriasis exacerbations. Finally, metabolomic research resulted in the proposal of a hypothesis on the contribution of Malassezia-synthesized aryl hydrocarbon receptor (AhR) ligands to basal cell carcinoma through UV radiation-induced carcinogenesis.
Topics: Humans; Malassezia; Mycoses
PubMed: 22232373
DOI: 10.1128/CMR.00021-11 -
Mycoses Jan 2010The molecular characterization of Malassezia spp. isolates from animals and humans has not been thoroughly studied. We have analysed the DNA profile by random amplified... (Comparative Study)
Comparative Study Review
The molecular characterization of Malassezia spp. isolates from animals and humans has not been thoroughly studied. We have analysed the DNA profile by random amplified polymorphic DNA (RAPD)-PCR to compare the genetic diversity between isolates from the external ears of cattle, dogs and humans. The analysis of electrophoretic profiles on 8% polyacrylamide gel and their phenograms showed genetic heterogeneity between RAPD profiles of Malassezia furfur and Malassezia slooffiae isolates from humans and cattle and between Malassezia pachydermatis isolates from dogs and cattle. Intra-species variations in DNA pattern of Malassezia isolates and the presence of specific genetic types in cattle, dogs or humans were observed. A review of genetic heterogeneity of these yeast in veterinary and human medicine studies is given considering a possible transmission animal to human or human to animal. Additional studies must clarify the differences between the RAPD band patterns observed in this and other studies, which would facilitate monitoring of Malassezia spp. carriage in domestic animals and in humans.
Topics: Animals; Cattle; Cluster Analysis; DNA Fingerprinting; DNA, Fungal; Dermatomycoses; Dogs; Electrophoresis, Polyacrylamide Gel; Genetic Variation; Genotype; Humans; Malassezia; Mycological Typing Techniques; Random Amplified Polymorphic DNA Technique
PubMed: 19298360
DOI: 10.1111/j.1439-0507.2008.01658.x -
Medical Mycology Oct 1999Malassezia pachydermatis is of importance in both veterinary and human medicine. Its taxonomic status and physiological characteristics are now better understood. Skin... (Review)
Review
Malassezia pachydermatis is of importance in both veterinary and human medicine. Its taxonomic status and physiological characteristics are now better understood. Skin disease associated with this lipophilic yeast is now commonly recognized, especially in dogs. However, further studies are required to elucidate the mechanisms which allow this yeast to proliferate and induce disease. Skin colonization is common in pet carnivores which consequently constitute a source of M. pachydermatis for susceptible humans. In the future, the development of efficient typing systems should allow better understanding of the transmission mechanisms.
Topics: Animals; Dermatomycoses; Dog Diseases; Dogs; Humans; Malassezia; Otitis; Skin
PubMed: 10520154
DOI: 10.1046/j.1365-280x.1999.00237.x -
PLoS Pathogens 2012
Review
Topics: Animals; Dermatomycoses; Eczema; Host-Parasite Interactions; Humans; Malassezia; Phylogeny; Scalp Dermatoses
PubMed: 22737067
DOI: 10.1371/journal.ppat.1002701 -
Clinical Microbiology Reviews Jan 2002Malassezia species are members of the human cutaneous commensal flora, in addition to causing a wide range of cutaneous and systemic diseases in suitably predisposed... (Review)
Review
Malassezia species are members of the human cutaneous commensal flora, in addition to causing a wide range of cutaneous and systemic diseases in suitably predisposed individuals. Studies examining cellular and humoral immune responses specific to Malassezia species in patients with Malassezia-associated diseases and healthy controls have generally been unable to define significant differences in their immune response. The use of varied antigenic preparations and strains from different Malassezia classifications may partly be responsible for this, although these problems can now be overcome by using techniques based on recent work defining some important antigens and also a new taxonomy for the genus. The finding that the genus Malassezia is immunomodulatory is important in understanding its ability to cause disease. Stimulation of the reticuloendothelial system and activation of the complement cascade contrasts with its ability to suppress cytokine release and downregulate phagocytic uptake and killing. The lipid-rich layer around the yeast appears to be pivotal in this alteration of phenotype. Defining the nonspecific immune response to Malassezia species and the way in which the organisms modulate it may well be the key to understanding how Malassezia species can exist as both commensals and pathogens.
Topics: Dermatomycoses; Fungemia; Humans; Infant, Newborn; Malassezia; Skin; Tinea Versicolor
PubMed: 11781265
DOI: 10.1128/CMR.15.1.21-57.2002 -
Clinics in Dermatology 2013The implication of the yeast genus Malassezia in skin diseases has been characterized by controversy, since the first description of the fungal nature of pityriasis... (Review)
Review
The implication of the yeast genus Malassezia in skin diseases has been characterized by controversy, since the first description of the fungal nature of pityriasis versicolor in 1846 by Eichstedt. This is underscored by the existence of Malassezia yeasts as commensal but also by their implication in diseases with distinct absence of inflammation despite the heavy fungal load (pityriasis versicolor) or with characteristic inflammation (eg, seborrheic dermatitis, atopic dermatitis, folliculitis, or psoriasis). The description of 14 Malassezia species and subsequent worldwide epidemiologic studies did not reveal pathogenic species but rather disease-associated subtypes within species. Emerging evidence demonstrates that the interaction of Malassezia yeasts with the skin is multifaceted and entails constituents of the fungal wall (melanin, lipid cover), enzymes (lipases, phospholipases), and metabolic products (indoles), as well as the cellular components of the epidermis (keratinocytes, dendritic cells, and melanocytes). Understanding the complexity of their interactions will highlight the controversies on the clinical presentation of Malassezia-associated diseases and unravel the complexity of skin homeostatic mechanisms.
Topics: Dermatomycoses; Homeostasis; Humans; Malassezia; Skin
PubMed: 23806162
DOI: 10.1016/j.clindermatol.2013.01.012 -
Medical Mycology Jun 2007Malassezia yeasts are commensals of normal human skin, but also cause pityriasis versicolor, seborrhoeic dermatitis and evidence is accumulating that they play a... (Review)
Review
Malassezia yeasts are commensals of normal human skin, but also cause pityriasis versicolor, seborrhoeic dermatitis and evidence is accumulating that they play a significant role in atopic eczema/dermatitis syndrome (AEDS; formerly atopic dermatitis). The taxonomy of the genus has changed considerably and is likely to change more in the future. Our understanding of the interaction between Malassezia and the host demonstrates that it has the paradoxical ability to both stimulate and suppress the immune response directed against it and there is a fine balance in its existence at the interface between commensalism and pathogenicity.
Topics: Animal Diseases; Animals; Antibody Formation; Antifungal Agents; Cell Wall; Dermatitis, Atopic; Dermatomycoses; Humans; Immunity, Cellular; Immunity, Innate; Lipid Metabolism; Malassezia; Microbial Sensitivity Tests; Virulence
PubMed: 17510854
DOI: 10.1080/13693780701191373 -
Journal de Mycologie Medicale Jun 2021Malassezia species can induce the expression of interleukin-17 (IL-17), which plays an important role in the inflammatory and immune response in psoriasis (PS). The...
INTRODUCTION
Malassezia species can induce the expression of interleukin-17 (IL-17), which plays an important role in the inflammatory and immune response in psoriasis (PS). The purpose of this study was to investigate the Malassezia species composition in patients with PS and healthy individuals and explore the role of Malassezia species in the pathogenesis of PS.
MATERIALS AND METHODS
A total of 28 patients with PS and 10 age- and sex-matched healthy individuals participated in this study. Specimens collected from the lesional and non-lesional skin of patients with PS and the skin of healthy individuals were analyzed by using nested PCR.
RESULTS
The relative abundance of Malassezia species was 84.96% in healthy subjects, more than twice that in patients with PS (P<0.01). M. restricta (43.09%) and M. globosa (41.38%) were the main Malassezia species in patients with PS followed by M. furfur (4.84%) and M. sympodialis (2.49%). M. sympodialis accounted for 18. 81% of the Malassezia species in healthy subjects, which was nearly eight times higher than in patients with PS (P<0.01). Further, M. furfur was detected both on lesional and non-lesional psoriatic skin, but it was not found on the skin of healthy individuals.
CONCLUSIONS
The Malassezia species composition in patients with PS differed from that of healthy individuals. M. restricta and M. globosa were the main Malassezia species in patients with PS.
Topics: DNA, Fungal; Dermatomycoses; Female; Humans; Malassezia; Male; Middle Aged; Psoriasis; Severity of Illness Index; Skin
PubMed: 33454614
DOI: 10.1016/j.mycmed.2021.101111 -
Reviews of Infectious Diseases 1987Until recently, Malassezia furfur was thought to be a pathogen only in tinea versicolor. More recently, this lipophilic yeast has been recovered from sick neonates with... (Review)
Review
Until recently, Malassezia furfur was thought to be a pathogen only in tinea versicolor. More recently, this lipophilic yeast has been recovered from sick neonates with catheter-related infections. Malassezia fungemia was studied in seven patients, and the salient features of this infection in patients described in the literature were reviewed. Major risk factors include prolonged hospitalization, the presence of central venous catheters, and the use of intravenous fat emulsions. It is difficult to identify specific manifestations of fungemia in these complex cases occurring in patients with severe underlying disease; however, neonates often present with the signs and symptoms of sepsis and thrombocytopenia, whereas fever may be the only manifestation in adults. Some patients are asymptomatic. When symptoms are present, they resolve upon removal of the colonized catheter. The role of the lipophilic nature of Malassezia in the pathogenesis of infection is apparent from the ability of intravenous fat emulsions to support the growth of the fungus in vitro. A special solid medium that can be used to determine the true prevalence of malassezia fungemia has been devised. M. furfur must be considered in the differential diagnosis of opportunistic infections in patients receiving central hyperalimentation and should be sought by the culture of blood on appropriate medium.
Topics: Agar; Aged; Female; Humans; Infant, Newborn; Infant, Premature; Malassezia; Male; Middle Aged; Mycology; Mycoses; Parenteral Nutrition, Total; Plant Oils
PubMed: 3125578
DOI: 10.1093/clinids/9.4.743