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Frontiers in Cellular and Infection... 2020The skin microbial community is a multifunctional ecosystem aiding prevention of infections from transient pathogens, maintenance of host immune homeostasis, and skin... (Review)
Review
The skin microbial community is a multifunctional ecosystem aiding prevention of infections from transient pathogens, maintenance of host immune homeostasis, and skin health. A better understanding of the complex milieu of microbe-microbe and host-microbe interactions will be required to define the ecosystem's optimal function and enable rational design of microbiome targeted interventions. , a fungal genus currently comprising 18 species and numerous functionally distinct strains, are lipid-dependent basidiomycetous yeasts and integral components of the skin microbiome. The high proportion of in the skin microbiome makes understanding their role in healthy and diseased skin crucial to development of functional skin health knowledge and understanding of normal, healthy skin homeostasis. Over the last decade, new tools for culture, detection, and genetic manipulation have revealed not only the ubiquity of on skin but new pathogenic roles in seborrheic dermatitis, psoriasis, Crohn's disease, and pancreatic ductal carcinoma. Application of these tools continues to peel back the layers of /skin interactions, including clear examples of pathogenicity, commensalism, and potential protective or beneficial activities creating mutualism. Our increased understanding of host- and microbe-specific interactions should lead to identification of key factors that maintain skin in a state of healthy mutualism or, in turn, initiate pathogenic changes. These approaches are leading toward development of new therapeutic targets and treatment options. This review discusses recent developments that have expanded our understanding of 's role in the skin microbiome, with a focus on its multiple roles in health and disease as commensal, pathogen, and protector.
Topics: Ecosystem; Humans; Malassezia; Psoriasis; Skin; Symbiosis
PubMed: 33575223
DOI: 10.3389/fcimb.2020.614446 -
Medical Mycology Journal 2023The Malassezia species are dimorphic fungi that require lipids such as olive oil for their growth. They are constituents of the normal human skin microbiota and can...
The Malassezia species are dimorphic fungi that require lipids such as olive oil for their growth. They are constituents of the normal human skin microbiota and can affix to the host or other surfaces through the establishment of biofilms. Malassezia species are accountable for superficial mycoses like folliculitis. Additionally, they are capable of causing invasive infections, such as of the bloodstream, in neonates and immunocompromised patients, albeit infrequently. Catheter-associated bloodstream infections in neonates are the most commonly reported invasive cases. Remarkably, unlike other invasive fungal infections, neutropenia and the use of broad-spectrum antibiotics do not seem to contribute to the risk of invasive Malassezia infections. Nosocomial outbreaks of Malassezia infections have been reported. While most cases of invasive Malassezia infection are fungemia, they seldom give rise to disseminated lesions in various organs. The diagnosis can be confirmed by the visualization of characteristic yeasts through histologic or cytologic examination of a biopsy or needle aspiration specimen, or via positive culture results from sterile sites. The prognosis for invasive Malassezia infection is generally favorable, with few reports of treatment failure. Nevertheless, due to the limited number of cases, evidence-based treatment recommendations are wanting. Management of invasive Malassezia infections linked to central venous catheters includes removal of the catheter, cessation of intravenous lipid emulsion, and intravenous administration of appropriate antifungal agents.
Topics: Infant, Newborn; Humans; Malassezia; Dermatomycoses; Antifungal Agents; Invasive Fungal Infections; Central Venous Catheters; Catheter-Related Infections
PubMed: 38030275
DOI: 10.3314/mmj.23-003 -
Microbiology Spectrum Aug 2023The genus comprises lipid-dependent yeasts that have long been associated with common skin diseases, and have recently been linked with Crohn's disease and certain...
The genus comprises lipid-dependent yeasts that have long been associated with common skin diseases, and have recently been linked with Crohn's disease and certain cancers. Understanding susceptibility to diverse antimicrobial agents is crucial for identifying effective antifungal therapies. Here, we tested the efficacy of isavuconazole, itraconazole, terbinafine, and artemisinin against three species: , and . Using broth microdilution, we found antifungal properties for the two previously unstudied antimicrobials: isavuconazole and artemisinin. Overall, all species were particularly susceptible to itraconazole, with a MIC range from 0.007 to 0.110 μg/mL. The genus is known to be involved in a variety of skin conditions and has recently been associated with diseases such as Crohn's disease, pancreatic ductal carcinoma, and breast cancer. This work was completed to assess susceptibility to a variety of antimicrobial drugs on three species, in particular , which is an abundant species both on human skin and internal organs and has been implicated in Crohn's disease. We tested two previously unstudied drugs and developed a new testing method to overcome current limitations for measuring growth inhibition of slow-growing strains.
Topics: Humans; Antifungal Agents; Itraconazole; Malassezia; Crohn Disease; Dermatomycoses; Microbial Sensitivity Tests
PubMed: 37310217
DOI: 10.1128/spectrum.05076-22 -
Cold Spring Harbor Perspectives in... Aug 2014Several human skin diseases and disorders are associated with two groups of fungi, the dermatophytes and Malassezia. Although these skin-related problems are not... (Review)
Review
Several human skin diseases and disorders are associated with two groups of fungi, the dermatophytes and Malassezia. Although these skin-related problems are not generally life threatening, they are among the most common diseases and disorders of mankind. These fungi are phylogenetically divergent, with the dermatophytes within the Ascomycota and Malassezia within Basidiomycota. Genome analysis indicates that the adaptations to the skin environment are different in these two groups of fungi. Malassezia are dependent on host lipids and secrete lipases and phospholipases that likely release host fatty acids. The dermatophytes encode multiple enzymes with potential roles in modulating host interactions: polyketide synthases, nonribosomal peptide synthetases, LysM, proteases, kinases, and pseudokinases. These two fungal groups have maximized their interactions with the host using two very different mechanisms.
Topics: Arthrodermataceae; Dandruff; Dermatitis, Atopic; Dermatitis, Seborrheic; Dermatomycoses; Genome, Fungal; Host-Pathogen Interactions; Humans; Malassezia; Microbiota; Phylogeny; Skin; Tinea Versicolor
PubMed: 25085959
DOI: 10.1101/cshperspect.a019802 -
The Veterinary Clinics of North... Nov 1999The incidence of dermatitis and otitis resulting from overgrowth of M. pachydermatis is great enough that cytological sampling techniques should be considered a routine... (Review)
Review
The incidence of dermatitis and otitis resulting from overgrowth of M. pachydermatis is great enough that cytological sampling techniques should be considered a routine part of the dermatological examination. Because most cases of MD and Malassezia otitis cannot be grossly distinguished from bacterial pyoderma and otitis, respectively, efficiency in performing cytology testing of skin and ear canal exudate is essential to the successful diagnosis and management of pruritic skin diseases and otitis. Although Malassezia infections are rarely primary, therapy can be instituted to remove the yeast as a confounding factor while a differential diagnosis is pursued in evaluating the underlying disease process.
Topics: Animals; Cat Diseases; Cats; Dermatomycoses; Dog Diseases; Dogs; Humans; Malassezia; Otitis Externa; Zoonoses
PubMed: 10563001
DOI: 10.1016/s0195-5616(99)50128-9 -
Frontiers in Immunology 2023Head and neck dermatitis (HND) is a refractory phenotype of atopic dermatitis (AD) and can be a therapeutic challenge due to lack of responsiveness to conventional...
INTRODUCTION & OBJECTIVES
Head and neck dermatitis (HND) is a refractory phenotype of atopic dermatitis (AD) and can be a therapeutic challenge due to lack of responsiveness to conventional treatments. Previous studies have suggested that the microbiome and fungiome may play a role in inducing HND, but the underlying pathogenic mechanisms remain unknown. This study aimed to determine the link between HND and fungiome and to examine the contribution of .
MATERIALS AND METHODS
To identify the effect of the sensitization status of on HND, 312 patients diagnosed with AD were enrolled. To elucidate the mechanism underlying the effects of , human keratinocytes and dermal endothelial cells were cultured with and treated with Th2 cytokines. The downstream effects of various cytokines, including inflammation and angiogenesis, were investigated by real-time quantitative PCR. To identify the association between changes in lipid composition and sensitization status, D-squame tape stripping was performed. Lipid composition was evaluated by focusing on ceramide species using liquid chromatography coupled with tandem mass spectrometry.
RESULTS
Increased sensitization to was observed in patients with HND. Additionally, sensitization to was associated with increased disease severity in these patients. IL-4 treated human keratinocytes cultured with produced significantly more VEGF, VEGFR, IL-31, and IL-33. IL-4/ co-cultured dermal endothelial cells exhibited significantly elevated VEGFR, TGF-β, TNF-α, and IL-1β levels. Stratum corneum lipid analysis revealed decreased levels of esterified omega-hydroxyacyl-sphingosine, indicating skin barrier dysfunction in HND. Finally, growth was inhibited by the addition of these ceramides to culture media, while the growth of other microbiota, including , were not inhibited.
CONCLUSIONS
Under decreased levels of ceramide in AD patients with HND, would proliferate, which may enhance pro-inflammatory cytokine levels, angiogenesis, and tissue remodeling. Thus, it plays a central role in the pathogenesis of HND in AD.
Topics: Humans; Malassezia; Endothelial Cells; Interleukin-4; Cytokines; Dermatitis, Atopic; Ceramides; Lipids
PubMed: 36911720
DOI: 10.3389/fimmu.2023.1114321 -
Immunology and Allergy Clinics of North... Feb 2017There is little doubt that Malassezia spp plays a role in atopic dermatitis because it may interact with the local skin immune responses and barrier function, and... (Review)
Review
There is little doubt that Malassezia spp plays a role in atopic dermatitis because it may interact with the local skin immune responses and barrier function, and sensitization against this skin-colonizing yeast can correlate with disease activity. Also, antifungal therapy shows beneficial effects in some patients. However, the pathogenetic mechanism and mutual interaction between Malassezia spp and atopic dermatitis still remain partly unclear and need further investigation.
Topics: Allergens; Antigens, Fungal; Dermatitis, Atopic; Dermatomycoses; Humans; Immunization; Immunoglobulin E; Malassezia; Skin
PubMed: 27886911
DOI: 10.1016/j.iac.2016.08.012 -
Frontiers in Cellular and Infection... 2020The microbiota plays an integral role in shaping physical and functional aspects of the skin. While a healthy microbiota contributes to the maintenance of immune... (Review)
Review
The microbiota plays an integral role in shaping physical and functional aspects of the skin. While a healthy microbiota contributes to the maintenance of immune homeostasis, dysbiosis can result in the development of diverse skin pathologies. This dichotomous feature of the skin microbiota holds true not only for bacteria, but also for fungi that colonize the skin. As such, the yeast , which is by far the most abundant component of the skin mycobiota, is associated with a variety of skin disorders, of which some can be chronic and severe and have a significant impact on the quality of life of those affected. Understanding the causative relationship between and the development of such skin disorders requires in-depth knowledge of the mechanism by which the immune system interacts with and responds to the fungus. In this review, we will discuss recent advances in our understanding of the immune response to and how the implicated cells and cytokine pathways prevent uncontrolled fungal growth to maintain commensalism in the mammalian skin. We also review how the antifungal response is currently thought to affect the development and severity of inflammatory disorders of the skin and at distant sites.
Topics: Animals; Fungi; Malassezia; Microbiota; Quality of Life; Skin
PubMed: 32477963
DOI: 10.3389/fcimb.2020.00198 -
Microbiology Spectrum Jun 2022is a fungal genus found on the skin of humans and warm-blooded animals, with 18 species reported to date. In this study, we sequenced and annotated the genome of...
is a fungal genus found on the skin of humans and warm-blooded animals, with 18 species reported to date. In this study, we sequenced and annotated the genome of Malassezia arunalokei, which is the most recently identified species, and compared it with Malassezia restricta, the predominant isolate from human skin. Additionally, we reanalyzed previously reported mycobiome data sets with a species-level resolution to investigate distribution within the mycobiota of human facial skin. We discovered that the genome is 7.24 Mbp in size and encodes 4,117 protein-coding genes, all of which were clustered with M. restricta. We also found that the average nucleotide identity value of the genome was 93.5, compared with the genomes of three strains, including KCTC 27527. Our findings demonstrate that they indeed belong to different species and that may have experienced specific gene loss events during speciation. Furthermore, our study showed that was diverged from approximately 7.1 million years ago and indicated that is the most recently diverged species in the lineage to date. Finally, our analysis of the facial mycobiome of previously recruited cohorts revealed that abundance is not associated with seborrheic dermatitis/dandruff or acne, but was revealed to be more abundant on the forehead and cheek than on the scalp. is the fungus predominantly residing on the human skin and causes various skin diseases, including seborrheic dermatitis and dandruff. To date, 18 species have been reported, and among them, is the most predominant on human skin, especially on the scalp. In this study, we sequenced and analyzed the genome of , which is the most recently identified species, and compared it with . Moreover, we analyzed the fungal microbiome to investigate the distribution on human facial skin. We found that may have experienced specific gene loss events during speciation. Our study also showed that was diverged from approximately 7.1 million years ago and indicated that is the most recently diverged species in the lineage. Finally, our analysis of the facial mycobiome revealed that has higher relative abundance on the forehead and cheek than the scalp.
Topics: Animals; Dandruff; Dermatitis, Seborrheic; Malassezia; Skin
PubMed: 35647654
DOI: 10.1128/spectrum.00506-22 -
International Journal of Molecular... Mar 2023Several studies have reported the pathogenic role of in atopic dermatitis (AD); the significance of 's influence on AD needs to be further investigated. Dupilumab, a...
Several studies have reported the pathogenic role of in atopic dermatitis (AD); the significance of 's influence on AD needs to be further investigated. Dupilumab, a monoclonal antibody to anti-Interleukin (IL) 4Rα, and ruxolitinib, a Janus kinase (JAK)1/2 inhibitor, are the first approved biologics and inhibitors widely used for AD treatment. In this study, we aimed to investigate how () affects the skin barrier and inflammation in AD and interacts with the AD therapeutic agents ruxolitinib and anti-IL4Rα. To induce an in vitro AD model, a reconstructed human epidermis (RHE) was treated with IL-4 and IL-13. was inoculated on the surface of RHE, and anti-IL4Rα or ruxolitinib was supplemented to model treated AD lesions. Histological and molecular analyses were performed. Skin barrier and ceramide-related molecules were downregulated by and reverted by anti-IL4Rα and ruxolitinib. Antimicrobial peptides, VEGF, Th2-related, and JAK/STAT pathway molecules were upregulated by and suppressed by anti-IL4Rα and ruxolitinib. These findings show that aggravated skin barrier function and Th2 inflammation and decreased the efficacy of anti-IL4Rα and ruxolitinib.
Topics: Humans; Dermatitis, Atopic; Malassezia; Janus Kinases; STAT Transcription Factors; Signal Transduction; Epidermis; Inflammation
PubMed: 37047166
DOI: 10.3390/ijms24076171