Composition Of Skin Microbiome Research Articles

Novel skin defense peptides and microbiota contribute to disease resilience of the Ngäbe-Buglé leopard frog

Some of the amphibian populations in Panama are demonstrating slow recovery decades after severe declines caused by the invasion of the fungal pathogen Batrachochytrium dendrobatidis (Bd). However, new species remain to be described and assessed for the mechanisms of disease resilience. We identified seven skin defense peptides from a presumably novel leopard frog species in the Tabasará range, at Buäbti (Llano Tugrí), Ngäbe-Buglé Comarca, and Santa Fe, Veraguas, Panama, herein called the Ngäbe-Buglé leopard frog. Two of the peptides were previously known: brevinin-1BLb from Rana (Lithobates) blairi and a previously hypothesized “ancestral” peptide, ranatuerin-2BPa. We hypothesized that the peptides are active against Bd and shape the microbiome such that the skin bacterial communities are more similar to those of other leopard frogs than of co-occurring host species. Natural mixtures of the collected skin peptides showed a minimum inhibitory concentration against Bd of 100 μg/ml, which was similar to that of other leopard frogs that have been tested. All sampled individuals hosted high intensity of infection with Bd. We sampled nine other amphibian species in nearby habitats and found lower prevalence and intensities of Bd infection. In addition to the pathogen load, the skin microbiomes were examined using 16S rRNA gene targeted amplicon sequencing. When compared to nine co-occurring amphibians, the Ngäbe-Buglé leopard frog had similar skin bacterial richness and anti-Bd function, but the skin microbiome structure differed significantly among species. The community composition of the bacterial skin communities was strongly associated with the Bd infection load. In contrast, the skin microbiome composition of the Ngäbe-Buglé leopard frog was similar to that of five North American leopard frog populations and the sympatric and congeneric Rana (Lithobates) warszewitschii, with 29 of the 46 core bacteria all demonstrating anti-Bd activity in culture. Because of the high Bd infection load and prevalence in the Ngäbe-Buglé leopard frog, we suggest that treatment to reduce the Bd load in this species might reduce the chytridiomycosis risk in the co-occurring amphibian community, but could potentially disrupt the evolution of skin defenses that provide a mechanism for disease resilience in this species.

Evaluation of the Effects of Age, Sex, and Dexpanthenol-Containing Skin Care on the Facial and Body Skin Microbiome

Given the pivotal role played by the microbiome in skin health, it is important to understand how its composition varies with age, sex, and body site and regular use of topical products. Four studies were carried out to determine the effects of long-term (4-week) use of different dexpanthenol-containing topical products on the skin microbiome of a varied population with cosmetically dry skin. The skin microbiome composition was assessed before and after product usage. No significant changes in microbiome richness or diversity were found for the individual test products; however, a meta-analysis of the combined dataset did show changes in microbiome composition as a function of the subject’s sex, age, and body site. The work presented here demonstrates how the use of carefully formulated topical products on skin, when used in a way that is representative of real-life usage conditions, can respect the microbial diversity present on skin across a widely varied study population.

DNA metabarcoding analyses reveal fine-scale microbiome structures on Western Canadian bat wings.

Microbiomes play important roles in host health. White-nose syndrome (WNS), a fungal infection of bat wings and muzzles, has threatened bat populations across North America since 2006. Recent research suggest that the skin microbiome of bats may play a significant role in bat's susceptibility to WNS. However, relatively little is known about the skin microbiome composition and function in bats in Western Canada, a region with a high diversity of bats, but WNS has yet to be a major issue. Here, we revealed high bacterial and fungal diversities on the skin of three common bat species in Lillooet, British Columbia, including several highly prevalent microbial species that have been rarely reported in other regions. Our analyses showed fine-scale structures of bat wing microbiome based on local sites and bat species. The knowledge obtained from WNS-naïve bat populations in this study may help develop mitigation and management strategies against WNS.

Mask wearing impacts skin barrier function and microbiome profile in sensitive skin

Mask-wearing behavior, common in the post-COVID-19 era, raises concerns for sensitive skin. This split-face study investigated mask-related changes in skin barrier function and microbiome composition among 30 female volunteers with sensitive skin and assessed the mitigating effects of a moisturizer containing biological lipids and probiotics. Skin physiological indicators (transepidermal water loss, erythema index, stratum corneum hydration, pH, temperature) of masked and unmasked areas were collected at baseline, after three hours of mask-wearing, post-tape stripping, and after 24 h, respectively. Microbiome samples collected from the masked areas before and after wearing a medical mask were analyzed with bioinformatics methods. Mask-wearing significantly weakened barrier function in both masked and adjacent unmasked areas, while reducing bacterial diversity. It was also associated with an increase in Cutibacterium (P = 0.110) and decreases in Streptococcus (P = 0.032) and Prevotella (P = 0.026) abundance. Moisturizer application prior to mask-wearing significantly reduced transepidermal water loss and erythema (both P < 0.001) and further improved erythema after 24 h (P = 0.048). These findings demonstrate that mask-wearing can disrupt the skin barrier and microbiome in individuals with sensitive skin and applying a moisturizer beforehand can mitigate mask-related discomforts by aiding barrier repair and reducing sensitivity.

Unraveling the Role of the Skin Microbiome in Immunodermatological Diseases: Implications for Therapeutic Interventions

The skin microbiome, comprising diverse microbial communities, plays a pivotal role in maintaining cutaneous homeostasis and modulating immune responses in immunodermatological diseases. This review provides an overview of recent research investigating the interplay between the skin microbiome and autoimmune, allergic, and inflammatory skin conditions, such as psoriasis, eczema, and acne vulgaris. This literature review was conducted using PubMed, searching the keywords "skin microbiome and immunodermatological diseases," "therapeutic interventions for skin microbiota," "skin disease and microbiome-host interaction," “immune response in dermatology,” “cutaneous microbiome,” "skin microbiome and allergies," "inflammatory skin conditions and microbiome," and “immune-mediated skin diseases.” A total of 53 articles were included in this review. Current evidence suggests that alterations in the skin microbiome composition, termed dysbiosis, may contribute to disease pathogenesis and exacerbate inflammation in immunodermatological disorders. Furthermore, microbial-derived metabolites and immune-modulating factors produced by commensal bacteria can influence local immune responses and skin barrier function. Future research directions include evaluating the mechanisms by which the skin microbiome interacts with the host immune system, identifying microbial biomarkers for disease diagnosis and prognosis, and exploring microbiome-targeted therapeutic interventions, such as probiotics, microbial transplantation, and microbial metabolite supplementation. By leveraging insights from microbiome research, personalized approaches to managing immunodermatological diseases may offer novel therapeutic avenues for restoring skin immune homeostasis and improving patient outcomes.

Simple tape-stripping method for highly reliable and quantitative analysis of skin microbiome.

The composition of human skin microbiome profoundly impacts host skin health and disease. However, the relationship between skin homeostasis or the development of skin diseases and daily changes in skin microbial composition is poorly understood. Longitudinal samplings at more frequent intervals would address this issue, while conventional sampling methods have technical difficulties, leading to limitations in sampling opportunities. Here, we developed a simple and stable tape-stripping method regardless of the operator's skill. Our method enables skin microbial sampling within 30 seconds and taking multiple skin microbial samples from the same body site. The amount of microbial DNA among multiple sampling sites could be measured within 13.5%. The sequencing results of multiple sampling showed high consistency, Pearson's correlation coefficient between multiple samples of 0.98. Furthermore, these results were comparable to those collected by the conventional swabbing method. These results demonstrate that our tape-stripping method enables simple microbiome collection and highly reliable quantitative skin microbiome analysis. These features of our method would lead to a further understanding of skin disease development or diagnosis of skin conditions in clinical research by increasing the opportunities for microbial sampling.

Microbiome and epigenetic variation in wild fish with low genetic diversity

Non-genetic sources of phenotypic variation, such as the epigenome and the microbiome, could be important contributors to adaptive variation for species with low genetic diversity. However, little is known about the complex interaction between these factors and the genetic diversity of the host, particularly in wild populations. Here, we examine the skin microbiome composition of two closely-related mangrove killifish species with different mating systems (self-fertilising and outcrossing) under sympatric and allopatric conditions. This allows us to partition the influence of the genotype and the environment on their microbiome and (previously described) epigenetic profiles. We find the diversity and community composition of the skin microbiome are strongly shaped by the environment and, to a lesser extent, by species-specific influences. Heterozygosity and microbiome alpha diversity, but not epigenetic variation, are associated with the fluctuating asymmetry of traits related to performance (vision) and behaviour (aggression). Our study identifies that a proportion of the epigenetic diversity and microbiome differentiation is unrelated to genetic variation, and we find evidence for an associative relationship between microbiome and epigenetic diversity in these wild populations. This suggests that both mechanisms could potentially contribute to variation in species with low genetic diversity.

Facial Skin Microbiome Composition and Functional Shift with Aging.

The change in the skin microbiome as individuals age is only partially known. To provide a better understanding of the impact of aging, whole-genome sequencing analysis was performed on facial skin swabs of 100 healthy female Caucasian volunteers grouped by age and wrinkle grade. Volunteers' metadata were collected through questionnaires and non-invasive biophysical measurements. A simple model and a biological statistical model were used to show the difference in skin microbiota composition between the two age groups. Taxonomic and non-metric multidimensional scaling analysis showed that the skin microbiome was more diverse in the older group (≥55 yo). There was also a significant decrease in Actinobacteria, namely in Cutibacterium acnes, and an increase in Corynebacterium kroppenstedtii. Some Streptococcus and Staphylococcus species belonging to the Firmicutes phylum and species belonging to the Proteobacteria phylum increased. In the 18-35 yo younger group, the microbiome was characterized by a significantly higher proportion of Cutibacterium acnes and Lactobacillus, most strikingly, Lactobacillus crispatus. The functional analysis using GO terms revealed that the young group has a higher significant expression of genes involved in biological and metabolic processes and in innate skin microbiome protection. The better comprehension of age-related impacts observed will later support the investigation of skin microbiome implications in antiaging protection.

Low-level pathogen infection and geographic location correlate with the skin microbiomes of Columbia spotted frogs (Rana luteiventris) in a montane landscape

The skin microbiome of amphibians can influence host susceptibility towards the fungal pathogen Batrachochytrium dendrobatidis (Bd), while simultaneously having the potential to be altered by Bd. Severe Bd infections are known to alter the amphibian skin microbiome; however, little is known about microbiome interactions in amphibians with low infection intensity. In addition to disease dynamics, environmental factors may influence the microbiome. To test for patterns in bacterial diversity based on pathogen infection and environmental factors, 399 Columbia spotted frogs (Rana luteiventris) were sampled throughout northern Idaho and northeastern Washington across two years. Bd prevalence and intensity were measured in 376 frogs, revealing a prevalence of 69%, but generally low infection intensity (Mean = 127 Bd zoospore equivalents among infected frogs). Skin bacterial communities were characterized in 92 frogs using 16S rRNA gene amplicon sequencing. Our results indicated correlations of decreasing Shannon diversity and evenness as infection intensity increased. Latitude was correlated with bacterial richness and Faith's Phylogenetic Diversity measures, indicating increased diversity in northern locations. Beta diversity (UniFrac) analyses revealed that skin microbiomes were distinct between infected and uninfected frogs, and infection intensity had a significant effect on microbiome composition. Site explained the majority of microbiome variation (weighted UniFrac: 57.5%), suggesting a combination of local habitat conditions explain variation, as only small proportions of variation could be explained by year, month, temperature, elevation, and latitude individually. Bacterial genera with potential for Bd-inhibitory properties were found with differential relative abundance in infected and uninfected frogs, with higher Stenotrophomonas and lower Pseudomonas relative abundance observed in infected frogs. Further study may indicate if Bd inhibition by members of the skin microbiome is an influence behind the low infection intensities observed and whether low Bd infection intensities are capable of altering skin microbiome composition.

Skin-Microbiome Assembly in Preterm Infants during the First Three Weeks of Life and Impact of Topical Coconut Oil Application

The structure and function of infant skin is not fully developed until 34 weeks of gestation, and this immaturity is associated with risk of late-onset sepsis (LOS). Topical coconut oil improves preterm-infant skin integrity and may reduce LOS. However, data on early-life skin-microbiome succession and potential effects of emollient skin care in preterm infants are scarce. We therefore collected skin-microbiome samples from the ear, axilla, and groin on days 1, 7, 14, and 21 from preterm infants born &lt;30 weeks of gestation as part of a randomized clinical trial of standard skin care vs. topical coconut oil. We found that within-sample microbiome diversity was highest on day 1 after birth, with a subsequent decline and emergence of Staphylococcus genus dominance from day 7. Moreover, microbiome assembly was less diverse in infants receiving coconut oil vs. standard skin care. Our study provides novel data on preterm-infant skin-microbiome composition and highlights the modifying potential of emollient skin care.

Skin Microbiome Composition and Key Factors of its Barrier Function

The skin is the largest organ of the human body, it creates protective barrier between the internal and external environment. Skin barrier damage may result in homeostasis imbalance, inflammation, or bacterial infection. The microbiome plays a crucial role in maintaining normal skin functioning: control of pathogenic diversity of microorganisms, stimulate immune cells, and modulate chronic dermatoses development. There are various mechanisms for restoring skin barrier function. They are associated with the microorganisms’ activity. Thus, skin restoration is an important task included in the general concept of atopic dermatitis management. One of such methods is the skin surface colonization with commensals, so significant role is assigned to the new dermatological drugs. The normalization of the microbiome in affected skin areas with cosmetic care products can significantly affect the result of skin barrier restoration.

Skin microbiome profile in people living with HIV/AIDS in Cameroon.

The presence of pathogens and the state of diseases, particularly skin diseases, may alter the composition of human skin microbiome. HIV infection has been reported to impair gut microbiome that leads to severe consequences. However, with cutaneous manifestations, that can be life-threatening, due to the opportunistic pathogens, little is known whether HIV infection might influence the skin microbiome and affect the skin homeostasis. This study catalogued the profile of skin microbiome of healthy Cameroonians, at three different skin sites, and compared them to the HIV-infected individuals. Taking advantage on the use of molecular assay coupled with next-generation sequencing, this study revealed that alpha-diversity of the skin microbiome was higher and beta-diversity was altered significantly in the HIV-infected Cameroonians than in the healthy ones. The relative abundance of skin microbes such as Micrococcus and Kocuria species was higher and Cutibacterium species was significantly lower in HIV-infected people, indicating an early change in the human skin microbiome in response to the HIV infection. This phenotypical shift was not related to the number of CD4 T cell count thus the cause remains to be identified. Overall, these data may offer an important lead on the role of skin microbiome in the determination of cutaneous disease state and the discovery of safe pharmacological preparations to treat microbial-related skin disorders.

Skin microbiome in autoimmune pemphigus: a comparative analysis of bacterial diversity in relation to treatment

Background. Autoimmune pemphigus (AP) is a chronic, life-threatening disease of the skin and mucous membranes. Effective therapeutic options are currently available, but mortality in AP patients is higher than in the general population. The leading causes of death are infectious complications. Recent years have revealed the key role of microbiome alteration in a number of skin diseases. There is an increasing number of published studies examining the skin microbiome in patients with AP, but they have a number of limitations and require further research to understand the role of skin microbial composition in the course of AP. Aims: to study the composition of skin microbiome by culture method in patients with AP (in active stage and in remission), to perform correlation analysis of microbiome composition and therapy received. Materials and methods. Experimental prospective comparative study. Forty-four patients with diagnosed AP (16 men, 36.4%; 28 women, 63.6%; mean age 51.5±13.1 years) and 10 controls (7 women, 70%; 3 men, 30%; mean age 40±12.5 years) were included. Patients were enrolled between November 2021 and June 2023 at the V.A. Rakhmanov Clinic of Skin and Venereal Diseases. Results. Seventy-nine skin samples were obtained and analysed. Only bacterial growth was detected in all submitted samples. No statistically significant difference was found between the composition of the microbiome of the unchanged skin of patients with AP in the active stage and in remission and the control group. In patients in the active stage of AP, a significant difference was found between the composition of the microbiome from rash elements and unchanged skin. S. aureus prevails on the skin from rash elements, and S. hominis dominates on unchanged skin. In patients before the start of glucocortlcosteroid (GCS) therapy, a predominance of S. aureus in the samples and a decrease in microbial diversity is noted. In patients receiving GCS therapy, S. hominis and S. epidermidis predominate, and greater microbial diversity is also noted. Conclusions. The study revealed that the skin microbiome from the rash elements of patients with AP undergoes significant changes during the active stage of the disease, mainly due to colonisation of the skin by S. aureus. However, against the background of therapy with systemic GCS there is a tendency to normalisation of skin microflora composition, which demonstrates that there are no differences in the composition of the microbiome of patients in remission of AP and control groups.

Skin Microbiome Composition is Associated with Radiation Dermatitis in Breast Cancer Patients Undergoing Radiation after Reconstructive Surgery: A Prospective, Longitudinal Study

Approximately 95% of breast cancer (BC) patients receiving radiotherapy (RT) develop varying degrees of radiation dermatitis (RD), which can greatly affect the patient's quality of life and aesthetics. Severe acute RD can lead to interruption or delay of RT. Currently, there is no consensus on the prevention and management of RD. The skin microbiota (SM), which are mainly composed of bacteria and fungi, are essential for skin homeostasis and microbial dysbiosis is correlated with the onset and progression of many common skin diseases. However, to date, research on the role of the SM in RD remains scarce. This prospective, longitudinal study aims to analyze the association of SM with RD. We collected 200 SM samples both before and after RT from the region in the irradiated chest wall of 100 BC patients receiving RT after reconstructive surgery and samples from the corresponding region in the contralateral breast for bacterial 16S and fungal ITS (internal transcribed spacer) rRNA sequencing. Acute RD was graded according to the Toxicity Criteria of the Radiation Therapy Oncology Group (RTOG). Patients were divided into no or mild dermatitis (N/MD, RTOG grade 0 or 1) and severe dermatitis (SD, RTOG grade 2 and above). The compositional differences across groups were compared using STAMP and high-dimensional class comparisons by linear discriminant analysis of effect size (LEfSe). Differences in metabolic function between groups were predicted by the Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt) method. Significant differences were observed in the diversity and composition of the SM between N/MD and SD both before and after RT. Analysis of bacterial 16S sequencing (n = 89, 63 N/MD, 26 SD) showed significantly higher relative abundance of particular taxa such as Ralstonia, Truepera, Methyloversatilis genera and lower abundance of particular taxa including Staphylococcus, Corynebacterium genera in N/MD patients. Besides, analysis of fungal ITS sequencing (n = 71, 53 N/MD, 18 SD) showed significantly higher relative abundance of particular taxa such as Hypocreaceae family and lower abundance of particular taxa such as Sporidiobolus genus in N/MD patients. Pathways including fatty acid synthesis were predicted to be enriched in N/MD patients. The SM and pathway markers were identified in this study to be associated with the severity of acute RD in BC patients undergoing RT after reconstructive surgery. More patient data is needed to verify the current findings and the results of metagenomic, metatranscriptomic, and metabolomic analyses will further mine key biomarkers at the compositional and functional level.

Yearly variation coupled with social interactions shape the skin microbiome in free-ranging rhesus macaques.

While skin microbes are known to mediate human health and disease, there has been minimal research on the interactions between skin microbiota, social behavior, and year-to-year effects in non-human primates-important animal models for translational biomedical research. To examine these relationships, we analyzed skin microbes from 78 rhesus macaques living on Cayo Santiago Island, Puerto Rico. We considered age, sex, and social group membership, and characterized social behavior by assessing dominance rank and patterns of grooming as compared to nonsocial behaviors. To measure the effects of a shifting environment, we sampled skin microbiota (based on sequence analysis of the 16S rRNA V4 region) and assessed weather across sampling periods between 2013 and 2015. We hypothesized that, first, monkeys with similar social behavior and/or in the same social group would possess similar skin microbial composition due, in part, to physical contact, and, second, microbial diversity would differ across sampling periods. We found significant phylum-level differences between social groups in the core microbiome as well as an association between total grooming rates and alpha diversity in the complete microbiome, but no association between microbial diversity and measures of rank or other nonsocial behaviors. We also identified alpha and beta diversity differences in microbiota and differential taxa abundance across two sampling periods. Our findings indicate that social dynamics interact with yearly environmental changes to shape the skin microbiota in rhesus macaques, with potential implications for understanding the factors affecting the microbiome in humans, which share many biological and social characteristics with these animals. IMPORTANCE Primate studies are valuable for translational and evolutionary insights into the human microbiome. The majority of primate microbiome studies focus on the gut, so less is known about the factors impacting the microbes on skin and how their links affect health and behavior. Here, we probe the impact of social interactions and the yearly environmental changes on food-provisioned, free-ranging monkeys living on a small island. We expected animals that lived together and groomed each other would have more similar microbes on their skin, but surprisingly found that the external environment was a stronger influence on skin microbiome composition. These findings have implications for our understanding of the human skin microbiome, including potential manipulations to improve health and treat disease.

Skin and Gut Microbiome in Hidradenitis Suppurativa: A Systematic Review.

Hidradenitis suppurativa (HS) is a chronic skin disease that significantly impairs the quality of life of affected individuals. The disease is characterized by persistent purulent lesions in specific anatomical areas, and its pathophysiology involves multiple factors, including inflammation, genetics, the microbiome, and environmental components. Recent research suggests a potential role for pathogenic bacteria in HS, highlighting the importance of the communication between the human host and the microbiome in maintaining homeostasis and immune system reactivity. However, the exact mechanisms underlying the gut-skin microbial interactions in HS remain unclear. This systematic review aims to examine the existing literature on the differences in skin and gut microbiome composition between HS patients and healthy controls. The review identifies methodological inconsistencies and calls for further research to elucidate the microbiome's role in HS pathogenesis and to explore new therapeutic interventions. The review highlights the need for advancements in microbiome research methodologies, such as metataxonomics and metagenomics, to improve our understanding of the microbiota's impact on health and disease.

Skin maturation from birth to 10 years of age: Structure, function, composition and microbiome.

Infant and adult skin physiology differ in many ways; however, limited data exist for older children. To further investigate the maturation processes of healthy skin during childhood. Skin parameters were recorded in 80 participants of four age groups: babies (0-2 years), young children (3-6 years), older children (7-<10 years) and adults (25-40 years). Overall, skin barrier function continues to mature, reaching adult levels of transepidermal water loss (TEWL), lipid compactness, stratum corneum (SC) thickness and corneocyte size by the age of about 6 years. Higher levels of lactic acid and lower levels of total amino acids in the SC of babies and young children further indicate higher cell turnover rates. In all age groups, TEWL and skin surface hydration values remain higher on the face compared with the arm. Skin becomes darker and contains higher levels of melanin with increasing age. The composition of skin microbiome of the dorsal forearm in all children groups is distinct from that in adults, with Firmicutes predominating in the former and Proteobacteria in the latter. Skin physiology, along with the skin microbiome, continues to mature during early childhood in a site-specific manner.

The Cornified Envelope: A Versatile Contributor to the Epidermal Barrier

The Cornified Envelope: A Versatile Contributor to the Epidermal Barrier

Comparison of skin microbiome components analyzed by culture method in patients with autoimmune pemphigus

BACKGROUND: Autoimmune pemphigus is a group of severe, potentially fatal bullous dermatoses affecting both skin and mucous membranes. To date, the pathogenesis and therapeutic approaches to the disease have been well studied; despite this, secondary bacterial complications remain the leading cause of death in these patients. Study of qualitative and quantitative composition of skin microbiome in chronic dermatoses is an actual contemporary problem. These data allow one to investigate the influence of microorganisms on the disease severity, relapse rate and remission duration. Analysis of literature sources shows a high interest of scientific groups in the study of microbiome components of the skin and mucous membranes in patients with bullous dermatoses, however, similar works on autoimmune bullous vesicles are still limited.&#x0D; AIM: to compare the composition of the skin microbiome in patients with autoimmune pemphigus and a healthy control group based on the results of the culture method performed.&#x0D; MATERIALS AND METHODS: Experimental, prospective, comparative study. Seventeen patients with previously or first-time diagnosis of autoimmune vesicular disease, as well as a control group of 10 people were included in the study. Patients were enrolled between November 2021 and November 2022. Rakhmanov clinic. All study participants had their skin swabs taken (for patients with rash elements and with apparently unchanged skin in the back or chest area; for the control group, from healthy skin in the back area), after which the material was taken to the laboratory for culture study.&#x0D; RESULTS: Data from 17 patients (5 men, 29.5%; and 12 women, 70.5%; average age 5113.3 years) were analyzed. Also included were 10 individuals from the control group (7 women, 70%; and 3 men, 30%; mean age 4014.7 years). Bacterial growth was detected in all samples submitted. No other microgranisms were identified. Eleven bacterial species were detected on the skin from the rash elements. The most frequent species encountered were: Staphylococcus aureus (in 70.59% of patients), Staphylococcus epidermidis (35.3%), Staphylococcus hominis (17.63%), Staphylococcus haemolyticus and Corynebacterium aurimucosum (11.8%). Twelve bacterial species were isolated on visibly unchanged skin. The most frequent were S. epidermidis (52.9%), S. aureus and S. hominis (35.3%), Staphylococcus capitis and Staphylococcus warneri (17.65%), Micrococcus luteus (11.76%). Fifteen bacterial species were identified in the control group. The following species were found most frequently: S. hominis (60%), S. capitis (50%), M. luteus (40%), S. epidermidis, S. haemolyticus and S. warneri (20%). The mean value of bacterial colony-forming units per 1 ml on rash elements was 5106.338752.46; on visibly unchanged skin 593.231223.06; in the control group 349.33915.52.&#x0D; CONCLUSIONS: We were able to obtain primary data on the composition of the skin microbiome in 17 patients with various types of autoimmune pemphigus and compare them with the control group. The data obtained demonstrate a great variety of microbial communities on the skin and a significant quantitative difference in the composition on the skin of patients and controls. A limitation of the study is the chosen cultural method, which cannot fully reflect all the diversity of microorganisms. To confirm the hypotheses put forward, we plan to conduct an additional study involving a larger number of patients and using genomic sequencing methods to identify microbial communities.

Gram-Negative Bacteria and Lipopolysaccharides as Risk Factors for the Occurrence of Diabetic Foot.

Imbalance of the skin microbial community could impair skin immune homeostasis and thus trigger skin lesions. Dysbiosis of skin microbiome may be involved in the early pathogenesis of diabetic foot (DF). However, the potential mechanism remains unclear. To investigate the dynamic composition and function of the foot skin microbiome with risk stratification for DF and assess whether dysbiosis of the skin microbiome induces diabetic skin lesions. We enrolled 90 consecutive subjects who were divided into 5 groups based on DF risk stratification: very low, low, moderate, and high risk for ulcers and a healthy control group. Integrated analysis of 16S ribosomal RNA and metagenomic sequencing of cotton swab samples was applied to identify the foot skin microbiome composition and functions in subjects. Then a mouse model of microbiota transplantation was used to evaluate the effects of the skin microbiome on diabetic skin lesions. The results demonstrated that, with the progression of diabetic complications, the proportion of gram-negative bacteria in plantar skin increased. At the species level, metagenome sequencing analyses showed Moraxella osloensis to be a representative core strain in the high-risk group. The major microbial metabolites affecting diabetic skin lesions were increased amino acid metabolites, and antibiotic resistance genes in microorganisms were abundant. Skin microbiota from high-risk patients induced more inflammatory cell infiltration, similar to the lipopolysaccharide (LPS)-stimulated response, which was inhibited by Toll-like receptor 4 (TLR4) antagonists. The skin microbiome in patients with diabetes undergoes dynamic changes at taxonomic and functional levels with the progression of diabetic complications. The increase in gram-negative bacteria on the skin surface through LPS-TLR4 signal transduction could induce inflammatory response in early diabetic skin lesions.