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Frontiers in Cellular and Infection... 2021
Topics: Malassezia; Saccharomyces cerevisiae; Skin; Symbiosis
PubMed: 33680995
DOI: 10.3389/fcimb.2021.659219 -
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 -
Polish Journal of Microbiology Dec 2022Seventy-seven strains of were included in this study. Biofilm and hydrolytic enzyme production were studied by using specific solid media. The Real-Time reverse...
Seventy-seven strains of were included in this study. Biofilm and hydrolytic enzyme production were studied by using specific solid media. The Real-Time reverse transcriptase qPCR method was applied to determine the overexpression of genes encoding the extracellular enzymes. All included species produced biofilms. No statistically significant difference was observed between species in biofilm formation ( = 0.567). All species produced lipase, and 95% of showed a strong enzymatic activity (Pz = 0.55 ± 0.02). A statistically significant difference was observed between the mean keratinase indices of and the other species ( = 0.005). The overexpression of one or more genes was observed in 100% of strains isolated from patients with folliculitis, 87.5% - with pityriasis versicolor, and 57.14% of the control group isolates. A statistically significant difference in the lipase gene expression ( = 0.042) was between the strains from patients with folliculitis and the control group. This investigation provides more information about the frequency of the production of the major enzymes considered virulence factors of species. Interestingly, the overexpression of one or more genes was observed in strains isolated from patients with disorders.
Topics: Humans; Malassezia; Virulence Factors; Tinea Versicolor; Lipase; Folliculitis
PubMed: 36473111
DOI: 10.33073/pjm-2022-047 -
Biophysics Reviews Mar 2023A microbiome consists of viruses, bacteria, archaea, fungi, and other microeukaryotes. It influences host immune systems and contributes to the development of various... (Review)
Review
A microbiome consists of viruses, bacteria, archaea, fungi, and other microeukaryotes. It influences host immune systems and contributes to the development of various diseases, such as obesity, diabetes, asthma, and skin diseases, including atopic dermatitis and seborrheic dermatitis. The skin is the largest organ in the human body and has various microorganisms on its surface. Several studies on skin microbiomes have illustrated the effects of their composition, metabolites, and interactions with host cells on diseases. However, most studies have focused on the bacterial microbiome rather than the fungal microbiome, namely, mycobiome, although emerging evidence indicates that fungi also play a critical role in skin microbiomes through interactions with the host cells. I briefly summarize the current progress in the analysis of mycobiomes on human skin. I focused on alteration of the skin mycobiome caused by atopic and seborrheic dermatitis, with an emphasis on the genus, which are the most dominant fungi residing here.
PubMed: 38505818
DOI: 10.1063/5.0136543 -
Proceedings of the National Academy of... Dec 2022form the dominant eukaryotic microbial community on the human skin. The genus possesses a repertoire of secretory hydrolytic enzymes involved in protein and lipid...
form the dominant eukaryotic microbial community on the human skin. The genus possesses a repertoire of secretory hydrolytic enzymes involved in protein and lipid metabolism which alter the external cutaneous environment. The exact role of most secreted enzymes, including those in interaction with the epithelial surface, is not well characterized. In this study, we compared the expression level of secreted proteases, lipases, phospholipases, and sphingomyelinases of in healthy subjects and seborrheic dermatitis or atopic dermatitis patients. We observed upregulated gene expression of the previously characterized secretory aspartyl protease in both diseased groups, in lesional and non-lesional skin sites, as compared to healthy subjects. To explore the functional roles of in skin disease, we generated a knockout mutant of the homologous protease in the genetically tractable . We observed the loss of resulted in dramatic changes in the cell adhesion and dispersal in both culture and a human 3D reconstituted epidermis model. In a murine model of colonization, we further demonstrated Mfsap1 contributes to inflammation as observed by reduced edema and inflammatory cell infiltration with the knockout mutant versus wildtype. Taken together, we show that this dominant secretory aspartyl protease has an important role in enabling a planktonic cellular state that can potentially aid in colonization and additionally as a virulence factor in barrier-compromised skin, further highlighting the importance of considering the contextual relevance when evaluating the functions of secreted microbial enzymes.
Topics: Humans; Animals; Mice; Peptide Hydrolases; Malassezia; Inflammation; Dermatitis, Atopic; Aspartic Acid Proteases; Aspartic Acid Endopeptidases
PubMed: 36442106
DOI: 10.1073/pnas.2212533119 -
Pharmaceuticals (Basel, Switzerland) Sep 2021Retinoids-a class of chemical compounds derived from vitamin A or chemically related to it-are used especially in dermatology, oncohematology and infectious diseases. It... (Review)
Review
Retinoids-a class of chemical compounds derived from vitamin A or chemically related to it-are used especially in dermatology, oncohematology and infectious diseases. It has been shown that retinoids-from their first generation-exert a potent antimicrobial activity against a wide range of pathogens, including bacteria, fungi and viruses. In this review, we summarize current evidence on retinoids' efficacy as antifungal agents. Studies were identified by searching electronic databases (MEDLINE, EMBASE, PubMed, Cochrane, Trials.gov) and reference lists of respective articles from 1946 to today. Only articles published in the English language were included. A total of thirty-nine articles were found according to the criteria. In this regard, to date, In vitro and In vivo studies have demonstrated the efficacy of retinoids against a broad-spectrum of human opportunistic fungal pathogens, including yeast fungi that normally colonize the skin and mucosal surfaces of humans such as spp., and , as well as environmental moulds such as spp., and many species of dermatophytes associated with fungal infections both in humans and animals. Notwithstanding a lack of double-blind clinical trials, the efficacy, tolerability and safety profile of retinoids have been demonstrated against localized and systemic fungal infections.
PubMed: 34681186
DOI: 10.3390/ph14100962 -
Life (Basel, Switzerland) Mar 2023The microbiome consists mostly of bacteria, but new evidence and developments in sequencing methods have shown that fungi play an important role in human health and in... (Review)
Review
The microbiome consists mostly of bacteria, but new evidence and developments in sequencing methods have shown that fungi play an important role in human health and in the stability of the microbiota. Scientific knowledge about the role of commensal fungi in intestinal, oral, vaginal and cutaneous communities has been increasing; however, more studies are still needed to better understand their action in these niches. To date, fungal research focuses primarily on opportunistic diseases caused by fungal species, leaving unclear the possible role of fungi as an integral part of the microbiota. Although they are much less abundant than bacteria, fungi such as species belonging to the genus , , and are some of the yeasts that have been in the focus of the scientific community because they inhabit various niches. In this review, we have summarized the current information about the yeasts that inhabit the human body, including some of the diseases that they can cause when the microbiota becomes unstable.
PubMed: 37109452
DOI: 10.3390/life13040924 -
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 -
Journal of Fungi (Basel, Switzerland) Feb 2023The molecular characterization of spp. isolates from animals and humans has not been thoroughly studied. Although a range of molecular methods has been developed for...
The molecular characterization of spp. isolates from animals and humans has not been thoroughly studied. Although a range of molecular methods has been developed for diagnosing species, they have several drawbacks, such as inefficiency in differentiating all the species, high cost and questionable reproducibility. The present study aimed to develop VNTR markers for genotyping isolated from clinical and animal samples. A total of 44 and 24 isolates were analyzed. Twelve VNTR markers were selected on seven different chromosomes (I, II, III, IV, V, VII and IX), six for each species. The highest discriminatory power for a single locus was obtained with the STR-MG1 marker (0.829) and STR-MR2 marker (0.818) for and , respectively. After the analysis of multiple loci, 24 genotypes were noted among 44 isolates in , with a discrimination index D of 0.943 and 15 genotypes were noted among 24 isolates in , with a discrimination index D of 0.967. An endogenous infection was detected in two patients. Different genotypes of strains colonized one patient. Interestingly, VNTR markers analysis revealed a carriage between a breeder and his dog in three cases for and two for . The FST (0.018 to 0.057) values indicate a low differentiation between the three populations of . These results suggest a dominant clonal mode of reproduction in . The typing of showed a genotypic diversity of the strains, which can cause various skin pathologies. However, patient five was colonized with strains having the same genotype collected from different body parts (back, shoulder). VNTR analysis was capable of identifying species with high accuracy and reliability. More importantly, the method would facilitate monitoring colonization in domestic animals and humans. It was shown that the patterns are stable and the method is discriminant, making it a powerful tool for epidemiological purposes.
PubMed: 36836377
DOI: 10.3390/jof9020263