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American Journal of Clinical Dermatology Jun 2019Acne vulgaris is a chronic skin disorder involving hair follicles and sebaceous glands. Multiple factors contribute to the disease, including skin microbes. The skin... (Review)
Review
Acne vulgaris is a chronic skin disorder involving hair follicles and sebaceous glands. Multiple factors contribute to the disease, including skin microbes. The skin microbiome in the follicle is composed of a diverse group of microorganisms. Among them, Propionibacterium acnes and Malassezia spp. have been linked to acne development through their influence on sebum secretion, comedone formation, and inflammatory response. Antibiotics targeting P. acnes have been the mainstay in acne treatment for the past four decades. Among them, macrolides, clindamycin, and tetracyclines are the most widely prescribed. As antibiotic resistance becomes an increasing concern in clinical practice, understanding the skin microbiome associated with acne and the effects of antibiotic use on the skin commensals is highly relevant and critical to clinicians. In this review, we summarize recent studies of the composition and dynamics of the skin microbiome in acne and the effects of antibiotic treatment on skin microbes.
Topics: Acne Vulgaris; Anti-Bacterial Agents; Drug Resistance, Bacterial; Hair Follicle; Humans; Malassezia; Microbiota; Propionibacterium acnes; Sebaceous Glands; Symbiosis; Treatment Outcome
PubMed: 30632097
DOI: 10.1007/s40257-018-00417-3 -
Frontiers in Cellular and Infection... 2020Yeasts of the genus, , formerly known as , are lipophilic yeasts, which are a part of the normal skin flora (microbiome). colonize the human skin after birth and must... (Review)
Review
Yeasts of the genus, , formerly known as , are lipophilic yeasts, which are a part of the normal skin flora (microbiome). colonize the human skin after birth and must therefore, as commensals, be normally tolerated by the human immune system. The yeasts also have a pathogenic potential where they can, under appropriate conditions, invade the stratum corneum and interact with the host immune system, both directly but also through chemical mediators. The species distribution on the skin and the pathogenetic potential of the yeast varies between different related diseases such as head and neck dermatitis, seborrheic dermatitis, pityriasis versicolor, and folliculitis. The diagnostic methods used to confirm the presence of yeasts include direct microcopy, culture based methods (often a combination of morphological features of the isolate combined with biochemical test), molecular based methods such as Polymerase Chain Reaction techniques, and Matrix Assisted Laser Desorption/Ionization-Time Of Flight mass spectrometry and the chemical imprint method Raman spectroscopy. Skin diseases caused by are usually treated with antifungal therapy and if there are associated inflammatory skin mechanisms this is often supplemented by anti-inflammatory therapy. The aim of this paper is to provide an overview of related skin disease, diagnostic methods and treatment options.
Topics: Dermatitis, Seborrheic; Folliculitis; Humans; Malassezia; Skin; Tinea Versicolor
PubMed: 32266163
DOI: 10.3389/fcimb.2020.00112 -
Acta Dermatovenerologica Alpina,... Jun 2022Malassezia is a commensal fungus that constitutes normal skin microbiota. However, in certain conditions and individuals, it may transform into a pathogenic yeast with... (Review)
Review
Malassezia is a commensal fungus that constitutes normal skin microbiota. However, in certain conditions and individuals, it may transform into a pathogenic yeast with multiple associated dermatological disorders and various clinical manifestations. This phenomenon is influenced by a unique host-agent interaction that triggers the production of several virulence factors, such as indoles, reactive oxygen species, azelaic acid, hyphae formation, and biofilm formation. This review article discusses Malassezia virulence factors that contribute to the transformation of Malassezia from commensal to pathogenic as well as their role in dermatological disorders, including pityriasis versicolor, seborrheic dermatitis, Malassezia folliculitis, atopic dermatitis, and psoriasis.
Topics: Dermatitis, Seborrheic; Dermatomycoses; Humans; Malassezia; Skin; Tinea Versicolor; Virulence Factors
PubMed: 35751534
DOI: No ID Found -
Medical Mycology Journal 2022This review describes the changes in yeast species names in the previous decade. Several yeast species have been reclassified to accommodate the "One fungus=One name"... (Review)
Review
This review describes the changes in yeast species names in the previous decade. Several yeast species have been reclassified to accommodate the "One fungus=One name" (1F=1N) principle of the Code. As the names of medically important yeasts have also been reviewed and revised, details of the genera Candida, Cryptococcus, Malassezia, and Trichosporon are described in Section 3, along with the history of name changes. Since the phylogenetic positions of Candida species in several clades have not been clarified, revision of this species has not been completed. Among the species that remain unrevised despite their importance in the medical field, we propose the transfer of six Candida species to be reclassified in the Nakaseomyces clade, including Nakaseomyces glabratus and Nakaseomyces nivalensis.
Topics: Trichosporon; Malassezia; Cryptococcus; Candida; Phylogeny
PubMed: 36450564
DOI: 10.3314/mmj.22.004 -
Frontiers in Cellular and Infection... 2020Lipophilic yeasts of the genus are important skin commensals and opportunistic skin pathogens in a variety of animals. The species was first isolated from the skin of... (Review)
Review
Lipophilic yeasts of the genus are important skin commensals and opportunistic skin pathogens in a variety of animals. The species was first isolated from the skin of a captive Indian rhinoceros with an exfoliative dermatitis in 1925, recognized as an important otic pathogen of dogs in the 1950's, and finally accepted, after several years of controversy, as a common cause of canine dermatitis in the 1990's. Since then, there has been considerable research into the biology of yeasts and their interaction with their animal hosts. In dogs and cats, is associated with ceruminous otitis externa and a "seborrhoeic" dermatitis, wherein pruritic, erythematous skin lesions, often with brown/black greasy, malodourous material matting hairs, preferentially develop in intertriginous areas. Skin disease is favored by folds, underlying hypersensitivity disorders, endocrinopathies, defects of cornification, and in cats, various visceral paraneoplastic syndromes. Diagnosis is based on detecting the yeast in compatible skin lesions, usually by cytology, and observing a clinical and mycological response to therapy. Treatment normally comprises topical or systemic azole therapy, often with miconazole-chlorhexidine shampoos or oral itraconazole or ketoconazole. Management of concurrent diseases is important to minimize relapses. Historically, wild-type isolates from dogs and cats were typically susceptible to azoles, with the exception of fluconazole, but emerging azole resistance in field strains has recently been associated with either mutations or quadruplication of the gene. These observations have prompted increased interest in alternative topical antifungal drugs, such as chlorhexidine, and various essential oils. Further clinical trials are awaited with interest.
Topics: Animals; Antifungal Agents; Cat Diseases; Cats; Dermatitis; Dog Diseases; Dogs; Drug Resistance, Multiple, Fungal; Malassezia; Skin; Zoonoses
PubMed: 32181160
DOI: 10.3389/fcimb.2020.00079 -
Journal of the American Academy of... Mar 2024Seborrheic dermatitis (SD) is a common skin disease with signs and symptoms that may vary by skin color, associated medical conditions, environmental factors, and... (Review)
Review
Seborrheic dermatitis (SD) is a common skin disease with signs and symptoms that may vary by skin color, associated medical conditions, environmental factors, and vehicle preference. Diagnosis of SD is based on presence of flaky, "greasy" patches, and/or thin plaques accompanied by erythema of the scalp, face, ears, chest, and groin and is associated with pruritus in many patients. The presentation may vary in different skin types and hyper- or hypopigmentation may occur, with or without erythema and minimal or no scaling. While the pathogenesis is not certain, 3 key factors generally agreed upon include lipid secretion by sebaceous glands, Malassezia spp. colonization, and some form of immunologic dysregulation that predisposes the patient to SD. Treatment involves reducing proliferation of, and inflammatory response to, Malassezia spp. Topical therapies, including antifungal agents and low potency corticosteroids, are the mainstay of treatment but may be limited by efficacy and side effects. Few novel treatments for SD are currently being studied; however, clinical trials assessing the use of topical phosphodiesterase-4 inhibitors have been completed. Improving outcomes in SD requires recognizing patient-specific manifestations/locations of the disease, including increased awareness of how it affects people of all skin types.
Topics: Humans; Dermatitis, Seborrheic; Antifungal Agents; Adrenal Cortex Hormones; Erythema; Malassezia
PubMed: 36538948
DOI: 10.1016/j.jaad.2022.12.017 -
Microbiome Nov 2017Most studies describing the human gut microbiome in healthy and diseased states have emphasized the bacterial component, but the fungal microbiome (i.e., the mycobiome)...
BACKGROUND
Most studies describing the human gut microbiome in healthy and diseased states have emphasized the bacterial component, but the fungal microbiome (i.e., the mycobiome) is beginning to gain recognition as a fundamental part of our microbiome. To date, human gut mycobiome studies have primarily been disease centric or in small cohorts of healthy individuals. To contribute to existing knowledge of the human mycobiome, we investigated the gut mycobiome of the Human Microbiome Project (HMP) cohort by sequencing the Internal Transcribed Spacer 2 (ITS2) region as well as the 18S rRNA gene.
RESULTS
Three hundred seventeen HMP stool samples were analyzed by ITS2 sequencing. Fecal fungal diversity was significantly lower in comparison to bacterial diversity. Yeast dominated the samples, comprising eight of the top 15 most abundant genera. Specifically, fungal communities were characterized by a high prevalence of Saccharomyces, Malassezia, and Candida, with S. cerevisiae, M. restricta, and C. albicans operational taxonomic units (OTUs) present in 96.8, 88.3, and 80.8% of samples, respectively. There was a high degree of inter- and intra-volunteer variability in fungal communities. However, S. cerevisiae, M. restricta, and C. albicans OTUs were found in 92.2, 78.3, and 63.6% of volunteers, respectively, in all samples donated over an approximately 1-year period. Metagenomic and 18S rRNA gene sequencing data agreed with ITS2 results; however, ITS2 sequencing provided greater resolution of the relatively low abundance mycobiome constituents.
CONCLUSIONS
Compared to bacterial communities, the human gut mycobiome is low in diversity and dominated by yeast including Saccharomyces, Malassezia, and Candida. Both inter- and intra-volunteer variability in the HMP cohort were high, revealing that unlike bacterial communities, an individual's mycobiome is no more similar to itself over time than to another person's. Nonetheless, several fungal species persisted across a majority of samples, evidence that a core gut mycobiome may exist. ITS2 sequencing data provided greater resolution of the mycobiome membership compared to metagenomic and 18S rRNA gene sequencing data, suggesting that it is a more sensitive method for studying the mycobiome of stool samples.
Topics: Candida; Cohort Studies; DNA, Ribosomal Spacer; Feces; Fungi; Gastrointestinal Microbiome; Genetic Variation; Healthy Volunteers; High-Throughput Nucleotide Sequencing; Humans; Malassezia; Metagenomics; Microbiota; Mycobiome; RNA, Ribosomal, 18S; Saccharomyces; Sequence Analysis, DNA
PubMed: 29178920
DOI: 10.1186/s40168-017-0373-4 -
Allergology International : Official... Oct 2018Sweat allergy is defined as a type I hypersensitivity against the contents of sweat, and is specifically observed in patients with atopic dermatitis (AD) and cholinergic... (Review)
Review
Sweat allergy is defined as a type I hypersensitivity against the contents of sweat, and is specifically observed in patients with atopic dermatitis (AD) and cholinergic urticaria (CholU). The allergic reaction is clinically revealed by positive reactions in the intradermal skin test and the basophil histamine release assay by sweat. A major histamine-releasing antigen in sweat, MGL_1304, has been identified. MGL_1304 is produced at a size of 29 kDa by Malassezia (M.) globosa and secreted into sweat after being processed and converted into the mature form of 17 kDa. It induces significant histamine release from basophils of patients with AD and/or CholU with MGL_1304-specific IgE, which is detected in their sera. Patients with AD also show cross-reactivity to MGL_1304-homologs in Malassezia restricta and Malassezia sympodialis, but MGL_1304 does not share cross antigenicity with human intrinsic proteins. Malassezia or its components may penetrate the damaged epidermis of AD lesions and interact with the skin immune system, resulting in the sensitization and reaction to the fungal antigen. As well as the improvement of impaired barrier functions by topical interventions, approaches such as anti-microbial treatment, the induction of tolerance and antibody/substance neutralizing the sweat antigen may be beneficial for the patients with intractable AD or CholU due to sweat allergy. The identification of antigens other than MGL_1304 in sweat should be the scope for future studies, which may lead to better understanding of sweat allergy and therapeutic innovations.
Topics: Antigens, Fungal; Histamine Release; Humans; Hypersensitivity; Malassezia; Sweat
PubMed: 30075993
DOI: 10.1016/j.alit.2018.07.002 -
Journal of Microbiology and... May 2021is the most abundant genus in the fungal microflora found on human skin, and it is associated with various skin diseases. Among the 18 different species of that have... (Review)
Review
is the most abundant genus in the fungal microflora found on human skin, and it is associated with various skin diseases. Among the 18 different species of that have been identified to date, and are the most predominant fungal species found on human skin. Several studies have suggested a possible link between and skin disorders. However, our knowledge on the physiology and pathogenesis of in human body is still limited. is unable to synthesize fatty acids; hence, it uptakes external fatty acids as a nutrient source for survival, a characteristic compensated by the secretion of lipases and degradation of sebum to produce and uptake external fatty acids. Although it has been reported that the activity of secreted lipases may contribute to pathogenesis of , majority of the data were indirect evidences; therefore, enzymes' role in the pathogenesis of infections is still largely unknown. This review focuses on the recent advances on in the context of an emerging interest for lipases and summarizes the existing knowledge on , diseases associated with the fungus, and the role of the reported lipases in its physiology and pathogenesis.
Topics: Dermatomycoses; Fungal Proteins; Humans; Lipase; Lipid Metabolism; Malassezia; Sebum; Skin; Virulence
PubMed: 33526754
DOI: 10.4014/jmb.2012.12048 -
International Journal of Cosmetic... Aug 2012Dandruff is characterized by a flaky, pruritic scalp and affects up to half the world's population post-puberty. The aetiology of dandruff is multifactorial, influenced... (Review)
Review
Dandruff is characterized by a flaky, pruritic scalp and affects up to half the world's population post-puberty. The aetiology of dandruff is multifactorial, influenced by Malassezia, sebum production and individual susceptibility. The commensal yeast Malassezia is a strong contributory factor to dandruff formation, but the presence of Malassezia on healthy scalps indicates that Malassezia alone is not a sufficient cause. A healthy stratum corneum (SC) forms a protective barrier to prevent water loss and maintain hydration of the scalp. It also protects against external insults such as microorganisms, including Malassezia, and toxic materials. Severe or chronic barrier damage can impair proper hydration, leading to atypical epidermal proliferation, keratinocyte differentiation and SC maturation, which may underlie some dandruff symptoms. The depleted and disorganized structural lipids of the dandruff SC are consistent with the weakened barrier indicated by elevated transepidermal water loss. Further evidence of a weakened barrier in dandruff includes subclinical inflammation and higher susceptibility to topical irritants. We are proposing that disruption of the SC of the scalp may facilitate dandruff generation, in part by affecting susceptibility to metabolites from Malassezia. Treatment of dandruff with cosmetic products to directly improve SC integrity while providing effective antifungal activity may thus be beneficial.
Topics: Dermatitis, Seborrheic; Epidermis; Humans; Malassezia; Sebum; Water Loss, Insensible
PubMed: 22515370
DOI: 10.1111/j.1468-2494.2012.00723.x