Composition and concentration of road salts alter amphibian microbial ecosystems: Insights from Ranadybowskii.

The yeasts of the genus Malassezia are part of the normal skin microbiota of a wide range of warm-blooded animals including humans. Within this genus, Malassezia pachydermatis is commonly found in the normal skin microbiota of a variety of animal hosts. Malassezia yeasts are considered lipid-dependent due to their inability to synthesize long chain fatty acids de novo. While M. pachydermatis is typically able to grow on Sabouraud’s agar (SGA) without lipid supplementation, certain strains display an atypical lipid dependency and are unable to grow on SGA. The aim of this work was to study the genomic differences between atypical M. pachydermatis strains unable to grow on SGA and the reference strain. The genomes of three atypical lipid-dependent M. pachydermatis strains were sequenced using Illumina technology and compared with the reference genome of M. pachydermatis neotype strain CBS 1879. A total of 397 small variants with a high or moderate impact on the protein were observed in genes involved in lipid metabolism. Of those small variants observed we highlight the ones observed in 12 out of the 13 genes encoding secretory lipases and in the CKI1 gene that is unique to M. pachydermatis within the genus. The analysis of those small variations suggested a variation in their ability to adapt to environmental changes and their requirements to grow in different culture media.

Hidradenitis suppurativa (HS) is a chronic inflammatory disease characterized by recurring skin lesions. Despite ongoing research, the exact cause underlying initiation and progression of disease remains unknown. While prior research has linked the skin microbiota to HS pathology, the role of viruses has remained unexplored. To investigate the skin virome, metagenomic sequencing of viral particles was performed on 144 skin samples from 57 individuals (39 HS patients and 18 controls). It was found that the virome is not only linked to BMI, but also to the presence and severity of HS, marking a diverging viral profile in the progression of disease. Despite no differences in alpha-diversity, HS patients exhibited a significantly higher beta-diversity compared to healthy controls, indicating a more personalized virome with reduced viral sharing among patients. We identified distinct groups of commonly shared phages, referred to as the core phageome, associated with either healthy controls or patients. Healthy controls displayed a higher abundance of two core Caudoviricetes phages predicted to infect Corynebacterium and Staphylococcus, comprising normal skin commensals. In contrast, HS patients carried previously uncharacterized phages that were more prevalent in advanced stages of the disease, which likely infect Peptoniphilus and Finegoldia, known HS-associated pathogens. Interestingly, genes involved in superinfection exclusion and antibiotic resistance could be found in phage genomes of healthy controls and HS patients, respectively. In conclusion, we report the existence of distinct core phages that may have clinical relevance in HS pathology by influencing skin bacteria through mechanisms such as superinfection exclusion and antibiotic resistance.IMPORTANCEAn increasing body of research showed that the microbiome has an important role in complex human disease. In line with this, here, we analyzed a longitudinal HS cohort and found a relationship between the skin virome and HS pathology. This relationship was defined by distinct groups of phages associated with either healthy controls or HS patients, yet, in both instances, capable of enhancing bacterial fitness. In healthy individuals, these phages were widely shared, fostering symbiosis by ensuring stability of the commensal skin microbiota. Conversely, in HS patients, these phages revealed a more individualistic nature and could contribute to dysbiosis by providing antibiotic resistance genes to bacterial pathogens. Overall, these findings point to a potential clinical significance of the virome in understanding and addressing HS pathology.

BackgroundHealthcare-associated infections (HAIs) remain a critical issue for healthcare systems worldwide, contributing significantly to increased morbidity, mortality, and healthcare costs. Post-surgical and device-associated HAIs are particularly concerning due to their severe and potentially fatal clinical outcomes. Although it remains largely unexplored, the interaction between host, implanted device, and human microbiota is increasingly recognized as a potential factor in HAI onset.MethodsIn this context, the present project aims to investigate—through 16S rRNA gene sequencing—the potential predictive and pathogenetic role of the skin and oral microbiota in patients undergoing vascular endografts (VEGs) implantation. Microbial profiles of patients who developed HAIs (HAI group) were compared with those who did not experience any post-surgical infectious complications (NoHAI group) to identify risk biomarkers, dysbiotic microbial patterns, and potential evolutionary trajectories that predispose to the HAIs onset.ResultsOral samples from HAI patients showed reduced microbial diversity (Shannon index, p-value = 0.597), whereas skin samples showed a significantly higher diversity (p-value = 0.023) compared with NoHAI patients. Furthermore, specific taxa emerged as potential indicators of HAIs susceptibility, including the phylum Firmicutes D (p-value < 0.001), the genera Staphylococcus (p-value = 0.011) and Haemophilus D (p-value = 0.036), and the species Prevotella denticola (p-value = 0.01) and Streptococcus mutans (p-value = 0.005).ConclusionThese results provide preliminary insights into the microbiological dynamics that may predispose patients to the onset of infections. Although further validation on larger and more diverse surgical populations is needed, these microbial signatures could represent promising targets for future pre-operative risk stratification and personalized preventive strategies in surgical patients.

Blood Culture Stewardship Efforts at a Comprehensive Cancer Center Reduced Isolation of Skin Flora Contaminants Without Compromising Patient Care

Hidradenitis suppurativa (HS) is a chronic skin disease in which the acute development of noduli, abscesses and in a later stage fistulas remains difficult to control, despite a wide range of recommended treatment options including immunomodulatory biologicals, surgical intervention and antibiotics. Besides being painful, associated lesions have an extensive impact on the quality of life. While HS is primarily an immune-mediated inflammatory disease, the skin microbiota plays a key role in its pathogenesis with pathogenic bacterial colonization of lesions observed. Bacteriophages, the viruses of bacteria, are used to treat a 52-year-old female HS patient with re-current colonization of lesions with Staphylococcus aureus. Phage therapy results in complete removal of lesions with a flare-free period of six months, along with a substantial improvement in the patient’s quality of life. The deployed experimental framework and the gained clinical experience will be valuable for future HS phage therapy research.

Skin microbiota, immune phenotypes, inflammatory response and hypertrophic scars: A Mendelian randomization study.

The epidermal immune microenvironment plays a central role in the pathogenesis of psoriasis.

The Karelian region, which spans the border between Finland and Russia, presents distinct environmental exposures and lifestyles on either side of the governmental border. In the more urbanized Finnish Karelia, allergic diseases are markedly more prevalent than in the more rural Russian Karelia. Prior studies, based on amplicon sequencing, have demonstrated major differences in skin microbiotas between the two populations. However, compositional differences in microbiota between sensitized and non-sensitized (NS) individuals have not been characterized. Here, in a selected population of 112 allergen-sensitized and NS adolescents, we used shotgun metagenomics to characterize the prokaryotic, eukaryotic and viral species in the skin potentially involved in allergic sensitization via distinct environmental exposures. In the more urban Finnish Karelia, the microbiome species composition was associated with IgE-mediated allergen sensitization status, while in the more rural Russian Karelia, the composition was associated with exposure to furry pets. Finnish participants showing high IgE-mediated sensitization to common allergens (allergen-specific IgE >7.5 kU/L) had less Cutibacterium acnes and Malassezia in their skin and displayed weaker interconnectedness of the microbial co-occurrence network compared with NS participants. Moreover, Malassezia restricta strain-level differences were related to allergen sensitization in both Finnish and Russian participants. In summary, we found distinct skin microbiomes between allergen-sensitized and NS participants and tracked the bacterial and fungal species associated with the degree of allergic sensitization in the more urbanized part of the Karelian region. These findings provide new insights into the factors that shape the human skin microbiome and influence allergic diseases.

Identifying the transition from ante-mortem to post-mortem odor in cadavers in an outdoor environment.

Skin microbiota differs between Black and White patients with cutaneous T-cell lymphoma.

This study investigates current scientific perspectives on the relationship between atopic dermatitis (AD) and food allergy (FA) in children, focusing on shared mechanisms, clinical implications and treatment approaches. A targeted analysis and synthesis of recent scientific publications was conducted, including studies on diagnostic strategies, immunopathology and clinical guidelines. Selection criteria emphasised thematic relevance to AD-FA interplay and innovations in therapy. Findings indicate that impaired skin barrier function, systemic sensitisation, and Th2-driven inflammation are central to both conditions. Filaggrin deficiency, lipid abnormalities and altered skin microbiota contribute to cutaneous and systemic immune dysregulation. Children with severe AD show a higher prevalence of food sensitisation, suggesting a bidirectional link. Sensitisation via damaged skin may promote gastrointestinal allergic responses. Effective diagnosis requires integrated use of history-taking, laboratory markers and provocation testing. Treatment should aim to restore skin integrity, modulate immune responses and manage dietary allergens. AD and FA share common pathophysiological pathways that warrant coordinated diagnostic and therapeutic strategies. Understanding their interrelation is essential for developing individualised prevention and treatment plans, especially in paediatric populations vulnerable to allergic progression.

ABSTRACTAptamers, short nucleic acid sequences with high specificity and affinity for their targets, are promising candidates for diagnostic applications due to their ability to detect a wide range of pathogens. We present a fluorescent bioimaging approach for detecting Pseudomonas aeruginosa, based on aptamer F23. Conjugated with fluorescent dye, its detection efficacy was evaluated on 15 Gram‐negative and ‐positive bacteria, including fixed and live cells, as homogeneous and heterogeneous populations. We developed an automated, open‐access software for quantifying microscopy images. Its high sensitivity enables accurate quantification of bacteria labeled with aptamers. For example, it successfully detected 1122 P. aeruginosa cells labeled with aptamer F23 out of a total of 1123 P. aeruginosa cells in a single image. With 200,000 analyzed bacteria, we demonstrated that the aptamer effectively detects various reference and clinical strains of P. aeruginosa, while failing to detect Gram‐positive Staphylococcus aureus, Staphylococcus haemolyticus, Staphylococcus epidermidis, and Corynebacterium striatum, as well as Gram‐negative Klebsiella pneumoniae, Acinetobacter baumannii, and Escherichia coli. This aptamer is therefore a promising tool to distinguish P. aeruginosa from different strains of the skin microbiota. However, our quantitative method also revealed partial labeling to other bacterial cells, highlighting the issue of refining aptamer selection to improve selectivity.

Current perspectives on the human skin microbiome: Functional insights and strategies for therapeutic modulation.

Medicinal plants play a vital role in treating various ailments. Scientific studies on the antimicrobial properties of plant components began in the late 19th century. Cyanthillium cinereum, an indigenous plant, is traditionally known for its medicinal properties. Its extract exhibits strong antibacterial activity, making it a promising agent with potential applications in the cosmetic industry. The local name for the plant is Poovamkurunnila (Malayalam), and it is one of the ten sacred flowers or ‘Dasapushpam’ with cultural and traditional significance in Kerala. The antibacterial activity was tested against skin microflora, which includes resident and transient microbes that may be harmless or pathogenic. Lotions are low-viscosity topical preparations intended for external skin application. Plant-based lotions are used for both cosmetic and medical purposes. The skin microflora, including Staphylococcus aureus and Micrococcus spp., was isolated and identified. Phytochemical analysis of the methanol extract revealed the presence of alkaloids, tannins, saponins, flavones, volatile oils, phenols, and steroids. This study aimed to evaluate the efficacy of Cyanthillium cinereum extract and a body lotion containing it, compared to a lotion without the extract, against the isolated skin flora. The plant extract showed antibacterial activity, producing a zone of inhibition of 21 mm against Staphylococcus aureus and 19 mm against Micrococcus spp. The lotion with the plant extract created zones of 20 mm and 17 mm for Staphylococcus aureus and Micrococcus spp., respectively. These results indicate that the body lotion containing Cyanthillium cinereum extract has greater antibacterial activity against skin flora than the control lotion.

Cosmetics with a rich texture can provide the perfect conditions for dangerous microorganisms to grow. Furthermore, each person's skin microbiota is different and could be dangerous to another. Sharing cosmetics could spread the pathogenicity of the skin and eyes in saloons for beauty. Determining the level of contaminants brought about by bacteria was the primary goal of this study in used skin and eye cosmetics that are sold to women in beauty shops as public makeup kits. Contaminated cosmetics were found among the 50 types examined in this investigation. Items including eye pencil, lip pencil, and mascara were examined. The pollutants ranged in concentration from 102 to 104 C.F.U./ml and included Pseudomonas aeruginosa, Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Klebsiella pneumonia, and fungi with the value Penicillium spp., Aspergillus fumigatus, and Candida albicans. Cosmetics are susceptible to microbiological proliferation since they contain water and additional nutrients. According to a recent study, certain microorganisms are dangerous to people. The research area's face products and other communal health and cosmetic items are highly polluted. Thus, it is crucial to create stringent inspection guidelines for cosmetic items both before and after they are put on the market, store used cosmetics in cool, dry locations, and raise awareness among staff of beauty salons. About the proper use, hygienic handling, and upkeep of medical supplies and cosmetics. The pollutants ranged from 102 to 104 C.F.U./ml and included bacteria such as Aspergillus fumigatus, Candida albicans, Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa, Escherichia coli, and Klebsiella pneumonia, as well as fungus like Penicillium spp.

Sensitive skin is typically characterized by dryness, reactivity and inflammation, often associated with a compromised skin barrier and an imbalanced microbiome. This study aims to investigate the effects and mechanisms of fermented tea seed oil in improving sensitive skin, particularly focusing on the skin lipid barrier and microbiome. Tea seed oil was fermented using biotechnology, and its lipid components were analysed both before and after fermentation. A double-blind, randomized, half-face controlled clinical trial was conducted on 25 Chinese young women with sensitive skin. Participants used a moisturizer containing 5% fermented tea seed oil or a base moisturizer for 4 weeks. Non-invasive methods were used to measure physiological parameters. Ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS) and high-throughput gene sequencing technologies were employed to analyse skin lipids and the microbiome. Fifty-three differential lipids were identified by comparing the lipid profiles of tea seed oil before and after fermentation. The most significant increase was observed in DHA-CoA, which has the potential to improve skin lipid metabolism and enhance the skin barrier. The participants showed significant improvements in skin hydration, redness reduction and facial wrinkles. Lipidomics analysis revealed notable changes in the skin lipid profile before and after treatment, with 41 and 15 differentially expressed lipids identified in the test and control groups, respectively. Microbiome results indicated no significant alterations in the diversity or abundance of skin microbiota after treatment. Nevertheless, the composition of the skin microbiota demonstrated a beneficial shift, with Propionibacterium acnes being suppressed while Streptococcus increased. These microbial changes are associated with skin barrier repair as well as sensitivity and inflammation. Fermented tea seed oil demonstrates notable clinical benefits for sensitive skin. It effectively regulates lipid metabolism and the composition of skin microbiota, thereby strengthening the lipid barrier and reducing the risk of potential inflammation. The increased presence of DHA-CoA in the fermented tea seed oil may serve as a key molecular contributor to its improved reparative efficacy.

Amphibian microbial communities are known to be shaped by host physiology and environmental factors, yet the relative roles of sexual dimorphism and tissue specialization remain poorly understood. Using 16S rRNA gene sequencing, we compared the gastrointestinal and integumentary microbiomes of a monomorphic Chinese frog population, Odorrana schmackeri, inhabiting identical montane streams. Our results showed distinct phylogenetic stratification between niches: Proteobacteria dominated both environmental microbiota and O. schmackeri gut and skin microbiotas but with differential sub-phylum specialization. The soil microbiota was dominated by unclassified_Vicinamibacteraceae, the water microbiota was Limnohabitans-dominated, the skin microbiota was dominated by Bordetella, and the gut microbiota was led by Acinetobacter. Alpha diversity analysis revealed significant tissue- and environmental-based divergences but no sexual differentiation, a pattern confirmed by beta diversity assessments showing stronger microbial community separation by tissue and environmental compartmentalization than by sex. Functional metagenomic prediction indicated convergent enrichment of metabolic pathways across host-associated and environmental communities. These results suggest that microbial community structure in O. schmackeri is principally governed by tissue-specific ecological selection pressures rather than host sexual characteristics. Our findings enhance understanding of microbiome assembly rules in vertebrate ectotherms and identify potential connections between microbiota in different ecological niches.

Background Asthma is a chronic airway disease increasingly linked to alterations in the human microbiome. Early-life disruptions in gut, airway, and skin microbiota are associated with impaired immune maturation and higher susceptibility to asthma and allergies. Aim The aim of this study is to review current knowledge on how the human microbiome influences the development, course, and severity of bronchial asthma, including its role in immune regulation, asthma phenotypes, the gut-lung axis, and potential microbiome-based therapies. Materials and Methods This review integrates current evidence using literature from PubMed, Google Scholar, and academic texts with keywords related to the microbiome, gut–lung axis, asthma, dysbiosis, and microbiome-targeted interventions. Experimental, cohort, and clinical studies were analysed. Results The microbiome plays a crucial role in asthma development, especially early in life. Microbial composition is shaped by delivery mode, breastfeeding, antibiotic exposure, and environmental diversity. Cesarean delivery and persistent dysbiosis increase asthma risk, while breastfeeding promotes protective profiles. Early gut dysbiosis - such as reduced SCFA-producing bacteria - affects immune maturation and contributes to distinct asthma phenotypes. Airway colonization by Proteobacteria (e.g., Haemophilus, Moraxella) is associated with severe disease, steroid resistance, and frequent exacerbations. Microbiome-targeted strategies, including probiotics, postbiotics, and fecal microbiota transplantation, show therapeutic potential. Conclusions The microbiome is a key regulator of immune development and a major contributor to asthma risk. Microbiome-based interventions are promising but require further well-designed clinical research.

BackgroundAmidst the current biodiversity crisis, amphibians are particularly endangered by the emergence of infectious diseases. The skin disease chytridiomycosis is caused by the fungi Batrachochytrium dendrobatidis (Bd) and B. salamandrivorans (Bsal), which may interact with bacterial symbionts present on the amphibian epidermis. Extensive research has explored the interactions between the amphibian microbiota and Bd; yet, little is known about its interactions with Bsal. In this paper, we used the ribbed newt (Pleurodeles waltl), a model species displaying pronounced among-individual variation in response to Bsal, to (1) determine whether susceptibility to Bsal and individual microbiota vary between source groups; (2) test whether susceptibility to Bsal can be predicted from skin microbiota before exposure and (3) quantify microbiota volatility over time to determine whether Bsal infection intensity and chytridiomycosis severity correlate with the magnitude of shifts in bacterial communities caused by Bsal exposure.ResultsOur results demonstrate that newts of different origin harbor distinct microbiota even under uniform rearing conditions. We show that Bsal infection intensity and disease severity cannot be predicted from the diversity, structure, or composition of the skin microbiota of P. waltl. Instead, a strong relation between newts’ source group and their response to Bsal suggests that other factors might underpin among-individual variation in Bsal susceptibility in this species. Moreover, our results indicate that the intensity of early Bsal infection and longer-term severity of chytridiomycosis do not correlate with the magnitude of microbiota change following Bsal exposure.ConclusionThese results demonstrate a limited involvement of the microbiota in Bsal dynamics in P. waltl, suggesting that other mechanisms contribute to individual Bsal susceptibility. Further research on the relation between chytrid pathogens and their amphibian hosts will be instrumental to improve the conservation of the most endangered vertebrate class on earth.Graphical Supplementary InformationThe online version contains supplementary material available at 10.1186/s42523-025-00485-x.