-
Frontiers in Immunology 2017The skin of mammalian organisms is home for a myriad of microbes. Many of these commensals are thought to have beneficial effects on the host by critically contributing... (Review)
Review
The skin of mammalian organisms is home for a myriad of microbes. Many of these commensals are thought to have beneficial effects on the host by critically contributing to immune homeostasis. Consequently, dysbiosis can have detrimental effects for the host that may manifest with inflammatory diseases at the barrier tissue. Besides bacteria, fungi make an important contribution to the microbiota and among these, the yeast widely dominates in most areas of the skin in healthy individuals. There is accumulating evidence that spp. are involved in a variety of skin disorders in humans ranging from non- or mildly inflammatory conditions such as dandruff and pityriasis versicolor to more severe inflammatory skin diseases like seborrheic eczema and atopic dermatitis. In addition, is strongly linked to the development of dermatitis and otitis externa in dogs. However, the association of spp. with such diseases remains poorly characterized. Until now, studies on the fungus-host interaction remain sparse and they are mostly limited to experiments with isolated host cells . They suggest a multifaceted crosstalk of spp. with the skin by direct activation of the host conserved pattern recognition receptors and indirectly the release of fungus-derived metabolites that can modulate the function of hematopoietic and/or non-hematopoietic cells in the barrier tissue. In this review, we discuss our current understanding of the host response to spp. in the mammalian skin.
PubMed: 29213272
DOI: 10.3389/fimmu.2017.01614 -
Frontiers in Immunology 2022Accumulating evidence indicates that patients with inflammatory bowel disease (IBD) have a significantly higher risk of developing different cancers, while the exact...
Accumulating evidence indicates that patients with inflammatory bowel disease (IBD) have a significantly higher risk of developing different cancers, while the exact mechanism involved is not yet fully understood. is a lipid-dependent opportunistic yeast, which colonizes on mammalian skin and internal organs. Also, dysbiosis in fungal communities accompanied by high level of are fairly common in inflammatory diseases such as IBD and various cancers. In cancer patients, higher levels of are associated with worse prognosis. Once it is ablated in tumor-bearing mice, their prognostic conditions will be improved. Moreover, manifests multiple proinflammatory biological properties, such as destruction of epithelial barrier, enrichment of inflammatory factors, and degradation of extracellular matrix (ECM), all of which have been reported to contribute to tumor initiation and malignant progression. Based on these facts, we hypothesize that high levels of together with mycobiome dysbiosis in patients with IBD, would aggravate the microecological imbalance, worsen the inflammatory response, and further promote tumorigenesis and deterioration. Herein, we will discuss the detrimental properties of and explore the key role of this fungus in the correlation between IBD and cancer, in order to take early surveillance and intervention to minimize the cancer risk in individuals with IBD.
Topics: Animals; Carcinogenesis; Cell Transformation, Neoplastic; Chronic Disease; Dysbiosis; Humans; Inflammatory Bowel Diseases; Malassezia; Mammals; Mice; Mycobiome
PubMed: 35309351
DOI: 10.3389/fimmu.2022.846469 -
Proceedings of the National Academy of... Aug 2023Fungi in the basidiomycete genus are the most prevalent eukaryotic microbes resident on the skin of human and other warm-blooded animals and have been implicated in...
Fungi in the basidiomycete genus are the most prevalent eukaryotic microbes resident on the skin of human and other warm-blooded animals and have been implicated in skin diseases and systemic disorders. Analysis of genomes revealed that key adaptations to the skin microenvironment have a direct genomic basis, and the identification of mating/meiotic genes suggests a capacity to reproduce sexually, even though no sexual cycle has yet been observed. In contrast to other bipolar or tetrapolar basidiomycetes that have either two linked mating-type-determining () loci or two loci on separate chromosomes, in species studied thus far the two loci are arranged in a pseudobipolar configuration (linked on the same chromosome but capable of recombining). By generating additional chromosome-level genome assemblies, and an improved phylogeny, we infer that the pseudobipolar arrangement was the ancestral state of this group and revealed six independent transitions to tetrapolarity, seemingly driven by centromere fission or translocations in centromere-flanking regions. Additionally, in an approach to uncover a sexual cycle, strains were engineered to express different alleles in the same cell. The resulting strains produce hyphae reminiscent of early steps in sexual development and display upregulation of genes associated with sexual development as well as others encoding lipases and a protease potentially relevant for pathogenesis of the fungus. Our study reveals a previously unseen genomic relocation of mating-type loci in fungi and provides insight toward the identification of a sexual cycle in , with possible implications for pathogenicity.
Topics: Humans; Malassezia; Evolution, Molecular; Basidiomycota; Fungi; Phylogeny; Reproduction; Genes, Mating Type, Fungal
PubMed: 37523560
DOI: 10.1073/pnas.2305094120 -
BMC Veterinary Research Nov 2021Rarely, Malassezia otitis presents as a painful, erosive otitis with an otic discharge containing Malassezia and neutrophils on cytology. There are no published reports... (Comparative Study)
Comparative Study
BACKGROUND
Rarely, Malassezia otitis presents as a painful, erosive otitis with an otic discharge containing Malassezia and neutrophils on cytology. There are no published reports of this type of suppurative Malassezia otitis (SMO). The role of Malassezia hypersensitivity in otitis is still unknown, and no association has been demonstrated with SMO. We compared Malassezia IgE levels, intradermal test and histology changes in SMO dogs with the more conventional Malassezia otitis (MO) presentation.
RESULTS
Three dogs (case 1, case 2 and case 3) were diagnosed with SMO, one dog (case 4) was diagnosed with unilateral MO and unilateral SMO, and one dog (case 5) was diagnosed with MO. Only one case (case 4) with SMO/MO had a positive Intradermal Allergy Test (IDAT) and elevated IgE levels for Malassezia. Histopathology findings from SMO revealed: interface dermatitis (case 1 and 3), lymphocytic dermatitis (case 2) and chronic hyperplastic eosinophilic and lymphoplasmacytic dermatitis (case 4). Histopathology findings from MO showed perivascular dermatitis (case 4 and 5). All the cases were treated successfully.
CONCLUSIONS
SMO presents with a distinct clinical phenotype in comparison with conventional MO. No consistent aetiology could be isolated. In these clinical cases it is possible that previous treatments could have influenced the results. More research is needed to understand the possible aetiologies and the pathogenesis of SMO.
Topics: Animals; Anti-Inflammatory Agents; Antifungal Agents; Dermatitis; Dog Diseases; Dogs; Ear Canal; Exudates and Transudates; Hypersensitivity; Immunoglobulin E; Intradermal Tests; Ketoconazole; Malassezia; Mometasone Furoate; Neutrophils; Otitis; Otitis Media, Suppurative; Prednisolone; Treatment Outcome; Triazoles
PubMed: 34794441
DOI: 10.1186/s12917-021-03066-7 -
Brazilian Journal of Microbiology :... Mar 2023Psoriasis is a chronic inflammatory disease that affects over 125 million people worldwide. Many studies have shown the importance of the microbiome for psoriasis...
INTRODUCTION
Psoriasis is a chronic inflammatory disease that affects over 125 million people worldwide. Many studies have shown the importance of the microbiome for psoriasis exacerbation.
AIM
Explore the fungal load and species composition of cultivable yeasts on the skin of psoriatic patients (PP) and healthy volunteers living in a tropical area and evaluate the susceptibility to antifungals.
METHODOLOGY
A cross-sectional study with 61 participants (35 patients and 26 healthy controls) was performed during August 2018 and May 2019. Clinical data were collected from patient interviewing and/or medical records review. Samples were collected by swabbing in up to five anatomic sites. Suggestive yeast colonies were counted and further identified by phenotypical tests, PCR-REA, and/or MALDI-TOF. Susceptibility of Malassezia spp. and Candida spp. to azoles, terbinafine, and amphotericin B was evaluated by broth microdilution.
RESULTS
Nearly 50% of the patients had moderate to severe psoriasis, and plaque-type psoriasis was the most common clinical form. Yeast colonies count was significantly more abundant among PP than healthy controls. Malassezia and Candida were the most abundant genus detected in all participants. Higher MIC values for ketoconazole and terbinafine were observed in Malassezia strains obtained from PP. Approximately 42% of Candida isolates from PP showed resistance to itraconazole in contrast to 12.5% of isolates from healthy controls. MIC values for fluconazole and amphotericin B were significantly different among Candida isolates from PP and healthy individuals.
CONCLUSION
This study showed that Malassezia and Candida strains from PP presented higher MIC values to widespread antifungal drugs than healthy individuals.
Topics: Humans; Antifungal Agents; Malassezia; Amphotericin B; Candida; Terbinafine; Cross-Sectional Studies; Saccharomyces cerevisiae; Fluconazole; Itraconazole; Microbial Sensitivity Tests; Drug Resistance, Fungal; Psoriasis
PubMed: 36480120
DOI: 10.1007/s42770-022-00883-2 -
Metabolomics : Official Journal of the... Apr 2021Microorganisms synthesize and release a large diversity of small molecules like volatile compounds, which allow them to relate and interact with their environment.... (Review)
Review
Learning about microbial language: possible interactions mediated by microbial volatile organic compounds (VOCs) and relevance to understanding Malassezia spp. metabolism.
BACKGROUND
Microorganisms synthesize and release a large diversity of small molecules like volatile compounds, which allow them to relate and interact with their environment. Volatile organic compounds (VOCs) are carbon-based compounds with low molecular weight and generally, high vapor pressure; because of their nature, they spread easily in the environment. Little is known about the role of VOCs in the interaction processes, and less is known about VOCs produced by Malassezia, a genus of yeasts that belongs to the human skin mycobiota. These yeasts have been associated with several dermatological diseases and currently, they are considered as emerging opportunistic yeasts. Research about secondary metabolites of these yeasts is limited. The pathogenic role and the molecular mechanisms involved in the infection processes of this genus are yet to be clarified. VOCs produced by Malassezia yeasts could play an important function in their metabolism; in addition, they might be involved in either beneficial or pathogenic host-interaction processes. Since these yeasts present differences in their nutritional requirements, like lipids to grow, it is possible that these variations of growth requirements also define differences in the volatile organic compounds produced in Malassezia species.
AIM OF REVIEW
We present a mini review about VOCs produced by microorganisms and Malassezia species, and hypothesize about their role in its metabolism, which would reveal clues about host-pathogen interaction.
KEY SCIENTIFIC CONCEPTS OF REVIEW
Since living organisms inhabit a similar environment, the interaction processes occur naturally; as a result, a signal and a response from participants of these processes become important in understanding several biological behaviors. The efforts to elucidate how living organisms interact has been studied from several perspectives. An important issue is that VOCs released by the microbiota plays a key role in the setup of relationships between living micro and macro organisms. The challenge is to determine what is the role of these VOCs produced by human microbiota in commensal/pathogenic scenarios, and how these allow understanding the species metabolism. Malassezia is part of the human mycobiota, and it is implicated in commensal and pathogenic processes. It is possible that their VOCs are involved in these behavioral changes, but the knowledge about this remains overlocked. For this reason, VOCs produced by microorganisms and Malassezia spp. and their role in several biological processes are the main topic in this review.
Topics: Animals; Host-Pathogen Interactions; Humans; Lipid Metabolism; Malassezia; Mycobiome; Skin; Volatile Organic Compounds; Yeasts
PubMed: 33825999
DOI: 10.1007/s11306-021-01786-3 -
Acta Dermato-venereologica Feb 2023Dandruff is a common scalp disorder with multiple microbial and host-related factors contributing to its aetiology, including alterations in scalp sebum. Despite...
Dandruff is a common scalp disorder with multiple microbial and host-related factors contributing to its aetiology, including alterations in scalp sebum. Despite existing evidence that the yeast Malassezia restricta plays a key role in the onset of dandruff, the interplay of these factors is poorly understood. Recently, squalene monohydroperoxide and malondialdehyde were established as biomarkers of dandruff-afflicted scalp, highlighting the role of sebum lipoperoxidation in the triggering and maintenance of dandruff, although its mechanism of action is unknown. The current study provides evidence that M. restricta mediates sebum peroxidation, leading to production of squalene monohydroperoxide and malondialdehyde. Furthermore, in vitro data show that these lipoperoxidation products act on epidermal cells and alter the skin barrier. These results support the role of Malassezia restricta-induced lipoperoxides as triggers of dandruff, which suggests that blocking their production could be a novel anti-dandruff treatment approach.
Topics: Humans; Dandruff; Malassezia; Malondialdehyde
PubMed: 36789756
DOI: 10.2340/actadv.v103.4808 -
Nihon Ishinkin Gakkai Zasshi = Japanese... 2006The genus Malassezia is now divided into eleven species. Different species initiate or aggravate different skin diseases. In seborroheic dermatitis, M. restricta play an... (Review)
Review
The genus Malassezia is now divided into eleven species. Different species initiate or aggravate different skin diseases. In seborroheic dermatitis, M. restricta play an important role, while in atopic dermatitis, M. globosa and/or M. restricta are major cutaneous microflora. M. globosa is a causative species of tinea versicolor, and this species is also a causative species of malassezia folliculitis. We should therefore obtain better knowledge of the ecological and pathogenic roles of malassezia.
Topics: Antifungal Agents; Dermatitis, Atopic; Dermatitis, Seborrheic; Humans; Malassezia; Tinea Versicolor
PubMed: 16699486
DOI: 10.3314/jjmm.47.75 -
PLoS Pathogens Sep 2022Malassezia, a lipophilic and lipid-dependent yeast, is a microorganism of current interest to mycobiologists because of its role as a commensal or pathogen in health... (Review)
Review
Malassezia, a lipophilic and lipid-dependent yeast, is a microorganism of current interest to mycobiologists because of its role as a commensal or pathogen in health conditions such as dermatological diseases, fungemia, and, as discovered recently, cancer and certain neurological disorders. Various novel approaches in the study of Malassezia have led to increased knowledge of the cellular and molecular mechanisms of this yeast. However, additional efforts are needed for more comprehensive understanding of the behavior of Malassezia in interactions with the host. This article reviews advances useful in the experimental field for Malassezia.
Topics: Malassezia; Saccharomyces cerevisiae
PubMed: 36074792
DOI: 10.1371/journal.ppat.1010784 -
Journal of Dental Research Jun 2020A broad range of fungi has been detected in molecular surveys of the oral mycobiome. However, knowledge is still lacking on interindividual variability of these...
A broad range of fungi has been detected in molecular surveys of the oral mycobiome. However, knowledge is still lacking on interindividual variability of these communities and the ecologic and clinical significance of oral fungal commensals. In this cross-sectional study, we use internal transcribed spacer 1 amplicon sequencing to evaluate the salivary mycobiome in 59 subjects, 36 of whom were scheduled to receive cancer chemotherapy. Analysis of the broad population structure of fungal communities in the whole cohort identified 2 well-demarcated genus-level community types (mycotypes), with and as the main taxa driving cluster partitioning. The mycotype had lower diversity than the mycotype and was positively correlated with cancer and steroid use in these subjects, smoking, caries, utilizing a removable prosthesis, and plaque index. Mycotypes were also associated with metabolically distinct bacteria indicative of divergent oral environments, with aciduric species enriched in the mycotype and inflammophilic bacteria increased in the mycotype. Similar to their fungal counterparts, coexisting bacterial communities associated with the mycotype showed lower diversity than those associated with the mycotype, suggesting that common environmental pressures affected bacteria and fungi. Mycotypes were also seen in an independent cohort of 24 subjects, in which cultivation revealed as viable oral mycobiome members, although the low-abundance was the only species recovered. There was a high degree of concordance between the molecular detection and cultivability of , while cultivation showed low sensitivity for detection of the mycotype. Overall, our work provides insights into the oral mycobiome landscape, revealing 2 community classes with apparently distinct ecologic constraints and specific associations with coexisting bacteria and clinical parameters. The utility of mycotypes as biomarkers for oral diseases warrants further study.
Topics: Adult; Aged; Bacteria; Cross-Sectional Studies; Female; Fungi; Humans; Malassezia; Male; Middle Aged; Mycobiome
PubMed: 32315566
DOI: 10.1177/0022034520915879