Skin Flora Research Articles (Page 1)

Aim S. epidermidis SE and S. haemolyticus SH are commensal bacteria from skin microbiota. Both species are involved in device-related infections, especially hip, knee or shoulder bone and joint infections. Recently, a multidrug-resistant SE clone has been reported in prosthesis infections. The aim of this study was to report three cases of SE or SH infections treated by debridement antibiotic and implant retention (DAIR) surgery and combination of delafloxacin (DFX)/rifampicin. Method Three patients were involved. Medical characteristic of the patients, the type of surgery, and the bacteria implicated were recovered. Resistance profiles and treatment with the follow up were analyzed. Results Two males and one female aged from 51, 64 and 74 y-old were selected according to the treatment. No history of prosthetic joint infection before was reported. A DAIR procedure was performed on 1 elbow and 2 hips. BMIs were normal. ASA scores were < 3. Fever was present for 2 patients and fistula for 1. No acute blood-borne infection was reported. The median time between symptom onset and surgical procedure were 5, 22 and 55 days. During the DAIR surgery, 2/4, 3/6 and 2/5 peroperative samples were positive. Two patients were infected with SE including a mixed morphotype for 1 patient and the last one was infected with SH. All strains were methicillin-resistant and levofloxacin-resistant. Delafloxacin MICs were 0.047, 0.094 and 0.125 and 0.25 mg/L. All patients were treated by delafloxacin (450 mg*2 per day) and rifampicin (600 or 900 mg per day). No adverse event was reported. Conclusions DFX MIC should be tested according to EUCAST guidelines including if strain are levofloxacin-resistant. According to EUCAST guidelines, 2 breakpoints are available. All strains were considered susceptible and a favorable outcome was noticed for two patients after a one year follow up. However, for the third patient, the one with two S. epidermidis morphotypes, a relapse was observed 1 year after the first revised surgery revealing only the less DFX susceptible SE stain (MIC 0.25 mg/L) suggesting a selection of the strain with the higher DFX MIC leading to a treatment failure. Pulsed-field gel electrophoresis analysis confirmed the genetic link between the isolates. Therefore, DFX treatment can be a therapeutic option in bone and joint infection, even for levofloxacin-resistant strain, only if the DFX MIC is less than 0.094 mg/L (Tessier et al. Journal of Antimicrobial Chemotherapy 2024).

Objective To explore the effects of two bathing methods, swaddle bath and tub bath, on physiological parameters and skin microbiota in late preterm infants. Design Prospective, no-blinded, randomised controlled trial. Setting Neonatal Intensive Care Unit in Foshan. Methods 56 late preterm infants were randomly divided into two groups: Intervention Group (swaddle bath, n = 28), control group (tub bath, n = 28). Physiological parameters, hemodynamics, stress responses and skin colony counts were evaluated pre(T 0 ), immediate(T 1 ), 30 min after bathing(T 2 ). Results The mean changes of rectal temperature, heart rate, respiration, and perfusion index (PI) in the intervention group were significantly higher than that of the control group immediately after bathing. The swaddle bath group showed less stress during the bathing process compared to the tub bath group (Crying: 1 vs. 8, p = 0.03, Clenched hands: 4 vs. 11, p = 0.04). No difference was found between the two groups, in terms of different peripheral oxygen saturation (SpO 2 ), pulse variability index (PVI), or the number of skin colonies. Conclusion Swaddle bath is a more recommended bathing for late preterm infants, as it ensures stable vital signs and blood perfusion while reducing stress manifestations during the bathing process. Clinical Trial Registration https://www.chictr.org.cn/indexEN.html , identifier ChiCTR2400087426.

Globally, the number of hypersensitivity reactions has increased with the usage of cosmetics, which mostly manifest as allergic or irritant contact dermatitis. This pathologic triad, now referred to as the microbiome-stress-allergy axis, is caused by the complex interactions of the skin microbiota, psychological stress, and immunological systems. Cosmetic contact allergy is prevalent globally, with lower positive patch test rates in European populations than those from the US, Asia, and the Middle East. Women are more susceptible due to exposure to allergens in cosmetics and household products. Incidence rates are higher in urban populations due to occupational and environmental factors. Certain occupations, such as healthcare professionals, hairdressers, and food handlers, are at particular risk of cosmetic-related hypersensitivity due to frequent exposure to soaps, disinfectants, hair dyes, and cosmetic chemicals, which compromise the skin barrier and increase allergen sensitization. This narrative review examines how the presence of allergens and preservatives in cosmetics can alter the skin barrier integrity and microbiome, making people more prone to inflammation and sensitization. In addition, it has been shown that psychological stress weakens skin immunity through cortisol and neuropeptide-based hormonal cascades, exacerbating skin disorders such as psoriasis, atopic dermatitis (AD), and acne. With an emphasis on mast cell function, T-cell imbalances, and compromised barriers, the review highlights recent research on immunological dysregulation caused by alteration of the microbiota and neuroendocrine variables. Clinical signs are discussed, such as urticaria, typical eczematous responses, and pigmentation diseases like Riehl melanosis. Populations at increased risk include women, healthcare professionals, those with an atopic background, and those who regularly use intricate skincare routines. Management strategies include using targeted patch testing to prevent allergies, probiotic or ceramide-based skincare products to rebuild the barrier, and psychodermatologic treatments to reduce stress. Adjunct pharmacologic therapy, including topical corticosteroids, calcineurin inhibitors, Janus kinase inhibitors, and phosphodiesterase-4 inhibitors, has shown efficacy in treating AD. Advances in microbiome profiling methods, such as metagenomic shotgun sequencing and amplicon-based sequencing, which are useful in profiling the skin microbiota, are spurring demand for personalized skincare. Artificial intelligence algorithms can predict component sensitivity to enhance tailored skincare by analyzing chemical compositions and comparing them with individual skin and allergy profiles. By integrating dermatological, immunological, and psychological knowledge, this review provides a thorough framework for understanding and managing cosmetic hypersensitivity in the modern era.

Context The skin is the largest organ of the body, and its proper care significantly influences the well-being of the entire organism. Therefore, the ingredients of cosmetics and dermocosmetics should inhibit processes leading to inflammation and degradation of skin macromolecules. Objective To select the most promising Rubus caesius L. extract for use in cosmetic and dermocosmetic applications. Materials and methods Water and ethanol extracts from leaves and stems of Rubus caesius L. (European dewberry, Rosaceae) were tested for their antioxidant properties, protective effects against pathogenic bacterial strains and the influence on tyrosinase and collagenase activity. The most biologically active extracts were selected and analyzed using the HPLC method to estimate the content of major phenolic acids and their ability to penetrate into and through porcine skin from hydrogels. Results Ethanol extracts from Rubus caesius L. demonstrated significant biological activity, particularly in scavenging the ABTS radical and inhibiting tyrosinase and collagenase activity. Furthermore, ethanol extracts were effective against pathogenic bacteria, but not against commensal skin microbiota. Ethanol extracts from leaves and stems were rich in phenolic acids. The permeation experiment through porcine skin from hydrogels revealed that gallic acid and neochlorogenic acid from ethanol leaves extract exhibited the highest permeation capability. Discussion and conclusion The ethanol extract demonstrated substantial activity in protecting the skin against pathogens, oxidative stress, and macromolecular degradation. The presence and transdermal permeability of phenolic acids were also confirmed. These findings highlight the high potential of Rubus caesius leaf ethanol extract for inclusion in cosmetic and dermocosmetic formulations.

What is the viable microbiome of the healthcare toilet?

Environmentally relevant levels of sulfamethoxazole (SMX) alter the skin and gastrointestinal microbiome of adult male and female zebrafish (Danio rerio).

Skin and gut microbiota composition and immune regulatory response differentiate IgE and non-IgE cow’s milk allergy patients with atopic dermatitis

Skin transcriptome and microbiome profiling are associated with Atlantic salmon resistance/susceptibility to sea lice infestation.

A combined metabolomics and biochemometrics approach for the rapid identification of antibacterial naphthyl derivatives from Guiera senegalensis leaves.

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

The emergence of antimicrobial-resistant bacteria in aquaculture has raised the need for alternative strategies to control fish infections. Antimicrobial-producing bacteria have been explored as probiotics or biocontrol agents, but their mechanisms of action and impact on host-associated microbiota remain poorly understood. Here, we identified Pseudomonas mosselii KH-ZF1, a bacterium isolated from fish epidermal mucus, as a producer of antimicrobial substances. When applied to zebrafish, strain KH-ZF1 transiently adhered to the epidermal mucus and altered the composition of the skin microbiota. Under an appropriate administration condition, strain KH-ZF1 treatment significantly improved survival in zebrafish infected with Yersinia ruckeri and suppressed pathogen growth on the skin surface. However, in the absence of strain KH-ZF1 or inappropriate conditions, Y. ruckeri dominated the epidermal bacterial community. The antimicrobial compound produced by strain KH-ZF1 was identified as Fluviol C, a pigmented metabolite previously reported from Pseudomonas fluorescens. Fluviol C inhibited the growth of multiple fish pathogens at experimentally determined concentrations (0.5-32 µg/mL) but exhibited toxicity to zebrafish even below its minimum inhibitory concentration. Intriguingly, fluviol C, at sub-inhibitory levels, induced bacterial substitution in the epidermal microbiota, mimicking the effects of strain KH-ZF1. These findings demonstrate that strain KH-ZF1 alters host resistance to infection by promoting bacterial substitution on the fish skin by producing fluviol C. Our study highlights a microbiota-mediated mechanism by which antimicrobial-producing bacteria can control infection through the fish epidermis, suggesting a potential microbiota-mediated approach for disease control in aquaculture.IMPORTANCEWe show that bacteria producing antibacterial substances, isolated from fish skin mucus, can inhibit percutaneous infections in aquatic environments. These bacteria effectively altered the skin mucus bacterial flora and suppressed pathogen growth. Fish skin acts as a barrier against infections, with its microorganisms being considered to play a crucial role in prevention. Our study highlighted the potential use of these specific microorganisms in the fish skin mucus as a novel fish disease control strategy. By targeting fish skin mucus bacteria that produce antimicrobial substances, we could develop a new approach to managing diseases in aquaculture, such as probiotics for fish skin. This research underscores the importance of studying fish epidermal microorganisms for innovative disease management.

While Tremella aurantialba (T. aurantialba) is known for its significant antioxidant and anti-inflammatory activities, its role in skin photoaging remains unclear. In this study, we elucidated the protective mechanisms of T. aurantialba extract (TAE) against ultraviolet A and ultraviolet B (UVA/UVB)-induced skin photoaging. Using UHPLC-Q-Orbitrap-MS analysis, a total of 24 compounds were identified from TAE, including trigonelline (22.83%), isonicotinic acid (18.16%), acetylcholine (16.66%), choline (15.02%), and 2-hydroxyphenylalanine (6.85%). In vitro investigations revealed that TAE significantly enhanced the survival rate of UVB-induced HaCaT cells, promoted cell migration, and increased the migration rates to above 50%, while concurrently reducing reactive oxygen species (ROS) levels. In vivo, TAE suppressed abnormal epidermal thickening and mast cell infiltration induced by UVA/UVB in the dorsal skin of mice, and facilitated the restoration of collagen fibers. Metabolomics analysis indicated that TAE mitigated photoaging mainly by modulating the sphingolipid and glycerophospholipid metabolic pathways. Skin microbiome analysis showed that TAE boosts Bacillota and Bacteroidota while suppressing Exiguobacterium and Lachnospiraceae, consequently restoring skin microbiota balance and facilitating skin repair. Transcriptome analysis demonstrated that genes modulated by TAE were primarily concentrated in lipid metabolism, circadian rhythm, and response to oxygen-containing compounds. This suggests TAE facilitated skin barrier repair and mitigated UVA/UVB-induced photoaging by modulating cellular physiological rhythms and lipid metabolism, while controlling oxidative stress. In conclusion, TAE mitigates UVA/UVB-induced damage via multi-targeted antioxidant, anti-inflammatory, and skin barrier repair-promoting effects, thereby establishing a scientific basis for its application in developing functional foods and cosmetics to target photoaging.

Background Retinol remains an essential component in anti-aging skincare; however, a subset of users develop intolerance, characterized by compromised barrier integrity and inflammation. The temporal dynamics of how skin microbiota and host metabolism co-evolve during retinol tolerance establishment remain poorly understood. Methods We conducted a prospective 28-day longitudinal study with 18 Chinese women (aged 25–40): 9 retinol-intolerant subjects monitored at baseline, adverse reaction phase, and tolerance establishment, while baseline data from 9 retinol-tolerant individuals served as controls. We integrated cutaneous phenotypic measurements, metagenomic sequencing, and untargeted metabolomics. Results In the intolerant group, skin phenotype assessment revealed a distinct biphasic response—an acute phase marked by increased stratum corneum hydration, reduced sebum secretion, lower skin pH, and improved wrinkle metrics, followed by a re-equilibration phase characterized by sustained barrier restoration. Metagenomic profiling of 969 microbial species demonstrated that, although overall microbial α-diversity remained stable across time points in both groups, key taxa in the intolerant group exhibited transient “rise-and-fall” dynamics. At baseline, the intolerant group exhibited overrepresentation of Cutibacterium acnes, whereas the tolerant group was enriched in potentially protective species, including Sphingomonas hankookensis and Acinetobacter johnsonii . Untargeted metabolomics showed marked temporal fluctuations with an initial phase of metabolic turbulence, followed by partial recovery. During the early adverse reaction phase in intolerant subjects, lipid and fatty acid metabolic pathways—specifically, glycerophospholipid, linoleic acid, α-linolenic acid, and ether lipid metabolism—were significantly upregulated, concomitant with the suppression of TCA cycle and sphingolipid activity. Conversely, as tolerance was established, enhanced activity in the TCA cycle, sphingolipid, ascorbate, and pentose metabolism pathways—coupled with a reduction in pro-inflammatory arachidonic acid derivatives-indicated metabolic reconstitution and restoration of barrier integrity. Discussion Integrated multi-omics correlation analyses further underscored the tightly interconnected regulation of host-microbe energy metabolism, antioxidant defenses, and membrane repair in response to retinol-induced stress. These findings elucidate the temporal interplay between host and microbial processes underpinning retinol tolerance and highlight baseline biomarkers that may facilitate personalized skincare interventions.

Poultry by-products (PBPs) are increasingly used in aquacultural environments and have emerged as a potential source of veterinary antibiotics and pathogens; however, the ecological risks remain unclear. This study investigated tissue-specific accumulation of 34 antibiotics and microbial risks in yellow catfish (Pelteobagrus fulvidraco) following exposure to PBPs. Among the 11 tissues analyzed, the data suggest that over 93% of antibiotic residues may be derived from PBPs, with concentrations ranging from 1.21 to 354.31 ng g-1, with the highest concentrations observed in bile, kidney, and liver. Bioaccumulation of tilmicosin, enrofloxacin, and florfenicol occurred via both dietary intake and dermal exposure, with log bioaccumulation factor (BAF) values of up to 3.79 for bile. High-throughput 16S rRNA sequencing revealed the consistent occurrence of Acinetobacter and Mycobacterium across fish tissues, feed, and water, with 40% of dominant taxa identified as known or suspected cross-species potentially pathogenic genera. A significant reduction in skin microbiota diversity further indicates a possible risk of exposure-induced dysbiosis. These findings highlight PBPs as vectors of both antibiotic residues and microbial disturbance, underscoring the need for targeted control of PBP-derived risks to safeguard freshwater ecosystem health.

Postbiotics are bioactive microbial metabolites recognized for their potential to support skin health and balance the microbiota. In this study, nonwoven fabrics and adult diaper prototypes, with and without postbiotic incorporation, were evaluated for their effects on skin microbiota, epidermal integrity, and cytotoxicity. In vitro assays using reconstructed human epidermis and keratinocyte cell lines demonstrated that postbiotic-containing samples maintained high tissue and cell viability. Microbiota diversity analyses confirmed that postbiotic formulations maintained a favorable ratio of Staphylococcus epidermidis to Staphylococcus aureus. Collectively, these findings indicate that ATA-coded postbiotic-embedded nonwoven and adult diaper prototypes are skin microbiota-friendly, safe for epidermal contact, and stable in their bioactive compound content. These results underscore the potential of postbiotics as functional agents in personal hygiene products to promote skin health.

White-nose syndrome is caused by Pseudogymnoascus destructans, leading to the near extinction of multiple bat populations in North America. This fungal pathogen has also been detected in China, but the prevalence and loads are relatively low in the hosts and environment. Previous studies have screened bat skin microbiomes in China to identify microbes that inhibit the growth of P. destructans. However, there is limited information on bacterial genera that possess properties that inhibit P. destructans in bat cave environments in China, particularly regarding antifungal metabolic pathways. We isolated 29 bacterial strains that have the ability to inhibit growth of P. destructans from the skin of bats and soil samples in China. These strains primarily belonged to several genera, including Acinetobacter, Pseudomonas, and Serratia. Gas chromatography-mass spectrometry analysis identified volatile organic compounds from strains that inhibit P. destructans, showing that 100 µL of α-Pinene, 2-Undecanone, 2-Nonanone, 2,5-Dimethylpyrazine, as well as 10 µL Benzaldehyde and Thujone, completely inhibited the growth of P. destructans and caused morphological damage to the mycelium. The soluble secondary metabolites from the antagonistic strains indicated that the bioactive compounds were predominantly small-molecule organic substances. Whole-genome sequencing of these antagonistic strains revealed that the most enriched potential antifungal gene clusters were associated with bacteriocins, siderophores, and β-lactones. β-Lactones were the primary gene cluster against P. destructans, and chitinases may play a crucial role in the antifungal process.IMPORTANCEBat skin and environmental microbiota may influence the colonization and persistence of Pseudogymnoascus destructans, thereby potentially affecting the occurrence of white-nose syndrome. Examining differences in these gene clusters contributes to understanding variation in the capacity of bacterial groups to have characteristics that inhibit P. destructans. This study lays the foundation for further exploration and elucidation of the mechanisms by which bacteria from bat skin and roosting environments suppress P. destructans growth in vitro.

Seborrheic dermatitis (SD) is a chronic, recurrent inflammatory skin disorder that commonly affects sebaceous-rich areas such as the scalp and central face. Although multifactorial, Malassezia spp., particularly M. globosa and M. restricta, play a central etiologic role. These lipophilic yeasts, part of the normal skin microbiota, can become opportunistic pathogens under conditions of dysbiosis, excessive sebum production, or barrier dysfunction. Metabolic products such as oleic acid disrupt epidermal integrity and induce keratinocyte hyperproliferation, while activation of pattern recognition receptors (PRRs) triggers IL-23/IL-17–mediated immune responses. This review aims to elucidate the pathogenic role of Malassezia spp. in SD and its clinical implications. Understanding this host–microbe interaction allows for targeted therapy emphasizing antifungal and anti-inflammatory strategies. By elucidating these mechanisms, new therapeutic approaches, such as antifungal agents and anti-inflammatory treatments, can be designed to better manage SD and improve patient outcomes. Understanding the role of Malassezia in SD highlights the importance of a balanced skin microbiome in maintaining skin health and preventing chronic inflammatory skin disorders.

A unique strain of Staphylococcus epidermidis, AIT01 (AIT, Airway Immune Trainer), identified in our previous research, has demonstrated immune-boosting properties. This study aimed to evaluate the systemic immune-modulatory effects and potential anti-tumor properties of this immune-enhancing skin microbiota strain. A series of ex vivo and in vivo experiments were conducted to assess immune cell proliferation, cytokine production, and anti-tumor efficacy. In ex vivo studies, splenocytes treated with the bacterial lysate or culture supernatant of the strain showed significantly increased viability in a concentration-dependent manner. Flow cytometry analysis revealed increased populations of dendritic cells, NK cells (Natural killer cells), and γδ T cells, with enhanced cytokine production, particularly IFN-γ (Interferon-γ) and perforin, in the lysate-treated group. When administered via intraperitoneal and intravenous routes in vivo, mice showed significant inhibition of melanoma growth upon receiving the bacterial lysate. Notably, pre-treatment demonstrated superior efficacy compared to post-treatment. Furthermore, the combination of the bacterial lysate with anti-PD-1 (anti-Programmed cell death protein-1) monoclonal antibody further suppressed tumor growth compared to anti-PD-1 monotherapy. These findings suggest that the AIT01 lysate enhances immune cell proliferation and cytokine production, contributing to its potent anti-tumor effects. The systemic delivery of this immune-boosting skin microbiota strain, particularly in combination with anti-PD-1 therapy, holds promise as an effective immunotherapeutic strategy against melanoma.Supplementary InformationThe online version contains supplementary material available at 10.1038/s41598-025-20581-x.

BackgroundPsoriasis is a chronic inflammatory skin disorder with unclear etiology. The roles of skin microbiome and metabolic dysregulation in psoriasis pathogenesis are not yet fully understood.MethodsWe conducted an integrated microbiome and untargeted metabolomic analyses on skin samples from 29 patients with psoriasis and 31 healthy controls. The skin microbiota was characterized using 16 S rRNA gene sequencing, and untargeted metabolomic profiling was performed using LC-MS/MS. Multivariate statistical analyses were used to identify differential microbes and metabolites, followed by correlation analyses to explore microbe-metabolite interactions.ResultsPsoriatic lesions exhibited significantly higher skin microbial alpha diversity compared to healthy controls. Principal component analysis revealed distinct microbial community structures between the two groups. At the genus level, Corynebacterium and Staphylococcus were significantly enriched in psoriatic lesions, while Cutibacterium was notably reduced. Metabolomic analysis identified 63 differential metabolites, with 39 upregulated and 24 downregulated in psoriatic lesions. These metabolites were primarily involved in lipid metabolism (particularly phospholipids and sphingolipids), amino acid metabolism, and inflammatory mediator pathways. Correlation analysis revealed significant associations between microbial alterations and metabolic dysregulation. Cutibacterium abundance was negatively correlated with inflammatory lipids and positively correlated with antioxidant metabolites, whereas Staphylococcus and Corynebacterium exhibited the opposite pattern. Notably, the abundance of Propionibacteriaceae strongly correlated with glutathione levels (r = 0.821, P < 0.001), indicating a potential role of microbiome-mediated oxidative stress in psoriasis.ConclusionsThis study highlights significant alterations in both the skin microbiome and metabolome in patients with psoriasis, revealing complex microbe-metabolite interaction networks. The findings suggest that microbial dysbiosis, particularly the decreased abundance of Cutibacterium and the increased abundance of Staphylococcus/Corynebacterium, may contribute to psoriasis pathogenesis by modulating lipid metabolism, inflammatory pathways, and oxidative stress responses.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12866-025-04395-5.

Background: In animals, staphylococci constitute a significant part of the normal skin microbiota and mucous membranes. There is limited information available on staphylococci isolated from healthy horses. These skin-associated bacteria can be easily transferred between animals and horse riders via direct contact. Patients undergoing hippotherapy (i.e., medical or therapeutic sessions with horses) are especially at risk of being colonized by horse skin-associated bacteria. However, it remains unclear whether equine skin is colonized by antimicrobial-resistant (AMR) opportunistic pathogens, which may be of concern to human health. Methods: We cultivate staphylococci from samples collected from healthy, non-vet-visiting horses who live on private farms in a rural area. In total, 61 strains were isolated and identified at the species level using matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF MS). Results: The diversity of Staphylococcus species in the equine skin microbiota was relatively high and, with the exception of S. aureus, all the other recovered strains were coagulase-negative staphylococci (CoNS). In total, eleven different staphylococcal species were identified: S. xylosus, S. sciuri, S. vitulinus, S. equorum, S. succinus, S. nepalensis, S. lentus, S. fleurettii, S. aureus, S. chromogenes, and S. simulans. Conclusions: These results indicate that healthy equine skin is colonized by opportunistic pathogens that can be causative agents of infections that are also severe in humans. The resistance among the isolated strains was observed in eight antimicrobials of the total tested and 36% (22/61) of the isolates were resistant to at least one antimicrobial. However, their resistance to critically important antibiotics used in human medicine was low. Seven isolates (11.5%; 7/61) were classified as multidrug-resistant (MDR). S. aureus (1/61) showed MDR and was methicillin-resistant. The S. aureus isolate contained genes conferring resistance to antibiotics, i.e., β-lactams (blaZ, mecA), aminoglycosides (aac(6′)/aph(2″)), and macrolide–lincosamide–streptogramin B (erm(B), erm(C), and lun(A/B)). Also CoNS harbored genes conferring resistance to β-lactams (blaZ), aminoglycosides (aac(6′)/aph(2″), ant(4′)-Ia), MLSB (erm(B), erm(C), lun(A/B)), and tetracycline (tetK, tetL).