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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 -
Veterinary Journal (London, England :... Apr 2024Malassezia are members of the mycobiome of dogs and cats. In the presence of an underlying disease, these yeasts can proliferate, attach to the skin or mucosa to induce... (Review)
Review
Malassezia are members of the mycobiome of dogs and cats. In the presence of an underlying disease, these yeasts can proliferate, attach to the skin or mucosa to induce a secondary Malassezia dermatitis, otitis externa or paronychia. Since allergic dermatitis is one of the most common underlying causes, diagnostic investigation for allergy is often indicated. Cats may suffer from various other underlying problems, especially where Malassezia dermatitis is generalised. Malassezia dermatitis in dogs and cats is chronic, relapsing and pruritic. Direct cytology from dermatological lesions and the ear canal, showing "peanut-shaped" budding yeasts, facilitates a rapid and reliable diagnosis. Topical treatment includes antiseptic and antifungal azole-based products. Systemic treatment with oral antifungals is indicated only in severe or refractory disease. Identification and treatment of the underlying cause is essential for an optimal response. In this evidence-based narrative review, we discuss the clinical presentation of Malassezia dermatitis in dogs and cats, underlying comorbidities, and diagnostic considerations. Treatment is discussed in light of emerging evidence of antifungal resistance and the authors' clinical experience.
Topics: Animals; Cats; Dogs; Malassezia; Dermatomycoses; Cat Diseases; Antifungal Agents; Dog Diseases; Neoplasm Recurrence, Local; Dermatitis
PubMed: 38431127
DOI: 10.1016/j.tvjl.2024.106084 -
Journal of Inflammation Research 2024As the body's largest organ, the skin harbors a highly diverse microbiota, playing a crucial role in resisting foreign pathogens, nurturing the immune system, and... (Review)
Review
As the body's largest organ, the skin harbors a highly diverse microbiota, playing a crucial role in resisting foreign pathogens, nurturing the immune system, and metabolizing natural products. The dysregulation of human skin microbiota is implicated in immune dysregulation and inflammatory responses. This review delineates the microbial alterations and immune dysregulation features in common Inflammatory Skin Diseases (ISDs) such as psoriasis, rosacea, atopic dermatitis(AD), seborrheic dermatitis(SD), diaper dermatitis(DD), and (MF).The skin microbiota, a complex and evolving community, undergoes changes in composition and function that can compromise the skin microbial barrier. These alterations induce water loss and abnormal lipid metabolism, contributing to the onset of ISDs. Additionally, microorganisms release toxins, like secreted α toxins and proteases, which may dissolve the stratum corneum, impairing skin barrier function and allowing entry into the bloodstream. Microbes entering the bloodstream activate molecular signals, leading to immune disorders and subsequent skin inflammatory responses. For instance, stimulates dendritic cells(DCs) to release IL-12 and IL-23, differentiating into a Th17 cell population and producing proinflammatory mediators such as IL-17, IL-22, TNF-α, and IFN-α.This review offers new insights into the role of the human skin microbiota in ISDs, paving the way for future skin microbiome-specific targeted therapies.
PubMed: 38375021
DOI: 10.2147/JIR.S441100 -
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 -
Experimental and Therapeutic Medicine Jun 2021Psoriasis is a common chronic, immune-mediated, inflammatory skin disorder, with a reported prevalence of 0.0-2.1% among children and 0.91-8.50% among adults, worldwide.... (Review)
Review
Psoriasis is a common chronic, immune-mediated, inflammatory skin disorder, with a reported prevalence of 0.0-2.1% among children and 0.91-8.50% among adults, worldwide. Psoriasis is induced by several environmental factors, including infection, alcohol consumption, drugs, trauma, acute withdrawal of systemic or potent topical corticosteroids, body mass index and endocrine disorders. Increasing evidence suggest that a variety of microorganisms play key roles in the induction and exacerbation of psoriasis. Pathogens, such as and are considered causal factors, presumably via superantigen activation of skin-seeking T cells. In addition, fungal pathogens, such as and , and viral agents, such as human immunodeficiency virus, hepatitis C virus infection and human papillomavirus, are also closely associated with psoriasis. Recently, several types of pathogens, such as infection, virus and scabies, have been reported to potentially trigger psoriasis. The present review discusses the underlying molecular mechanisms by which these infections influence psoriasis to provide a better understanding of the pathogenesis of psoriasis.
PubMed: 33850539
DOI: 10.3892/etm.2021.9999 -
Frontiers in Neurology 2019Parkinson's disease (PD) is a common debilitating neurodegenerative disease caused by a loss of dopamine neurons in the substantia nigra within the central nervous...
Parkinson's disease (PD) is a common debilitating neurodegenerative disease caused by a loss of dopamine neurons in the substantia nigra within the central nervous system (CNS). The process leading to this neuronal loss is poorly understood. Seborrheic dermatitis (SD) is a common benign inflammatory condition of the skin which mainly affects lipid-rich regions of the head and trunk. SD is caused by over proliferation of the lipophilic fungus . PD and SD are strongly associated. The increased PD risk following an SD diagnosis (OR = 1.69, 95% CI 1.36, 2.1; < 0.001) reported by Tanner and colleagues remains unexplained. were historically considered commensals confined to the skin. However, many recent studies report finding in internal organs, including the CNS. This raises the possibility that might be directly contributing to PD. Several lines of evidence support this hypothesis. AIDS is causally associated with both parkinsonism and SD, suggesting that weak T cell-mediated control of commensal microbes such as might contribute to both. Genetic polymorphisms associated with PD () increase availability of lipids within human cells, providing a suitable environment for . Four polymorphisms which increase PD risk also increase Crohn's disease risk; Crohn's disease is strongly associated with an immune response against fungi, particularly . Finally, hypha formation and melanin synthesis are stimulated by L-DOPA, which could promote invasiveness of dopamine neurons, and contribute to the accumulation of melanin in these neurons. Although 's presence in the substantia nigra remains to be confirmed, if play a role in PD etiology, antifungal drugs should be tested as a possible therapeutic intervention.
PubMed: 31396143
DOI: 10.3389/fneur.2019.00758 -
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 -
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 -
Nature Aug 2023A growing body of literature suggests that alterations in the human microbiome are causative of disease initiation and progression. Aykut et al. present data supporting...
A growing body of literature suggests that alterations in the human microbiome are causative of disease initiation and progression. Aykut et al. present data supporting the argument that alterations in the gut fungal microbiome (the “mycobiome”), along with the presence of fungal elements within pancreatic tissue (specifically those of the genus , are associated with pancreatic oncogenesis. Upon analyzing the human sequencing data presented in the original manuscript, we found few fungal reads in pancreatic tissue samples and did not identify differences in pancreatic or gut mycobiome composition between healthy and pancreatic ductal adenocarcinoma (PDAC) patients. Our re-analysis of these data does not support an association between an intrinsic pancreatic mycobiome and the development of human PDAC, and illustrates the challenges in analyzing microbiome sequencing data from low biomass samples.
Topics: Humans; Mycobiome; Pancreatic Neoplasms; Pancreas; Carcinogenesis
PubMed: 37532819
DOI: 10.1038/s41586-023-06292-1 -
Journal of Fungi (Basel, Switzerland) Oct 2018This review focuses on aspects of antimycotic therapy specific to veterinary medicine. In the first part, drug availability, limited mostly by economic consideration but... (Review)
Review
This review focuses on aspects of antimycotic therapy specific to veterinary medicine. In the first part, drug availability, limited mostly by economic consideration but also by clinical applicability and specific adverse effects, is described for polyenes, 5 fluorocytosine, azoles, echinocandins and terbinafine. In the second part, current knowledge and experience in the treatment of selected fungal infections are overviewed. These mycoses include disseminated mold infections in small animals (dogs and cats) and avian species, upper respiratory tract infections of small animals (sino-nasal and sino-orbital aspergillosis) and horses (guttural pouch mycosis), eumycetoma, infections caused by dimorphic fungi, (blastomycosis, histoplasmosis, coccidioidomycosis, paracoccidioidomycosis and sporothrichosis) and by yeasts and yeast-like microorganism ( spp. and ).
PubMed: 30380772
DOI: 10.3390/jof4040120