Dietary carotenoid supplementation has long-term and community-wide effects on the amphibian skin microbiome.

The amphibian skin microbiome plays a crucial role in host immunity and pathogen defence, yet we know little about the environmental drivers of skin microbial variation across host individuals. Inter-individual variation in the availability of micro-nutrients such as dietary carotenoids, which are involved in amphibian immunity, may be one factor that influences skin microbial assembly across different life history stages. We compared the effect of four carotenoid supplementation regimes during different life stages on the adult skin microbiome using a captive population of the critically endangered southern corroboree frog, Pseudophryne corroboree. We applied 16S rRNA sequencing paired with joint-species distribution models to examine the effect of supplementation on taxon abundances. We found that carotenoid supplementation had subtle yet taxonomically widespread effects on the skin microbiome, even 4.5 years post supplementation. Supplementation during any life-history stage tended to have a positive effect on the number of bacterial taxa detected, although explanatory power was low. Some genera were sensitive to supplementation pre-metamorphosis, but most demonstrated either additive or dominant effects, whereby supplementation during one life history stage had intermediate or similar effects, respectively, to supplementation across life. Carotenoid supplementation increased abundances of taxa belonging to lactic acid bacteria, including Lactococcus and Enterococcus, a group of bacteria that have previously been linked to protection against the amphibian fungal pathogen Batrachochytrium dendrobatidis (Bd). While the fitness benefits of these microbial shifts require further study, these results suggest a fundamental relationship between nutrition and the amphibian skin microbiome which may be critical to amphibian health and the development of novel conservation strategies.

Skin microbiome sampling in the preterm neonate.

Despite advances in our understanding of the human microbiome, there exist significant knowledge gaps in our understanding of the skin microbiome of the preterm neonate. Herein, we describe skin microbiome sampling of six preterm neonates at multiple timepoints, and compare the skin microbiome samples to environmental (crib/isolette swabs) and negative controls. Samples of the same type (skin, crib, control) were more similar than when compared by week or by patient.

Disordered cutaneous microbiota in systemic lupus erythematosus.

The correlation between systemic lupus erythematosus (SLE) and microbiota colonization has been receiving much attention during recent years. Here, we screened the cutaneous bacterial spectrums of 69 SLE patients, 49 healthy controls and 20 dermatomyositis (DM) patients and identified the specific changes of cutaneous microbial composition and abundance in SLE patients. We observed the decreasing diversity in community richness and evenness and the greater heterogeneity in SLE patients compared to healthy controls, which were also different from the cutaneous microbiome of DM patients. The skin microbial community disorders in SLE patients were correlated with several clinical features such as serum low complement level, gender, renal involvement and myositis. According to the Kruskal-Wallis (KW) test, receiver operating characteristic (ROC) curve and LDA Effect Size (LEfSe) analysis, several bacterial taxa such as Staphylococcus, especially Staphylococcus aureus and Staphylococcus epidermidis, were identified to be potential markers for SLE skin lesions. Furthermore, Picrust analysis showed that Staphylococcus aureus infection pathway was significantly enriched and exhibited a strong correlation with genus Staphylococcus in SLE patients. The changes in the composition and abundance of cutaneous microbiota in SLE patients suggest that the microbial dysbiosis is associated with the pathogenesis of SLE, which may be potentially reliable biomarker or therapeutic target for SLE.

The impact of NBUVB on microbial community profiling in the lesional skin of vitiligo subjects.

BACKGROUND: The impact of NBUVB on the cutaneous microbiota of vitiligo patients remains to be fully elucidated. METHODS: To characterize the cutaneous microbiota in vitiligo patients, cutaneous samples from 60 patients with vitiligo and after NBUVB irradiation were profiled using the Illumina MiSeq platform. Alpha diversity estimations revealed higher microbiota diversity in samples from patients with lesional skin. Beta diversity (Principal Component Analysis (PCA)) analysis showed that the bacterial community structure segregated differently between different groups. RESULTS: There was a statistically significant increase in the Sobs, ACE, and Chao indices in the NB group compared with NF group, as determined by t-test. The alpha diversity have no significant difference between NF and DB group. At the phylum level, Firmicutes, Proteobacteria and Actinobacteria were the most predominant phyla. Propionibacterium and Pseudomonas were the most predominant genera in each group. In addition, Staphylococcus, Bacillus and Prevotella were enriched in DF group compared to DB group. Propionibacterium was enriched in DB group compared to DF group. CONCLUSIONS: Our studies indicate differences in microbial community dynamics of the lesional and non-lesional sites of vitiligo subjects, with greater diversity and higher association between microbial communities of the unaffected site. And NBUVB irradiation might eliminate these differences.

The infantile cutaneous microbiome: A review.

Recent focus on the neonatal intestinal microbiome has advanced our knowledge of the complex interplay between the intestinal barrier, the developing immune system, and commensal and pathogenic organisms. Despite the parallel role of the infant skin in serving as both a barrier and an interface for priming the immune system, large gaps exist in our understanding of the infantile cutaneous microbiome. The skin microbiome changes and matures throughout infancy, becoming more diverse and developing the site specificity known to exist in adults. Delivery method initially determines the composition of the cutaneous microbiome, though this impact appears transient. Cutaneous microbes play a critical role in immune system development, particularly during the neonatal period, and microbes and immune cells have closely intertwined, reciprocal effects. The unique structure of newborn skin influences cutaneous microbial colonization and the development of dermatologic pathology. The development of the infantile skin barrier and cutaneous microbiome contributes to future skin pathology. Atopic dermatitis flares and seborrheic dermatitis have been linked to dysbiosis, while erythema toxicum neonatorum is an immune response to the establishment of normal bacterial skin flora. Physicians who care for infants should be aware of the impact of the infantile skin microbiome and its role in the development of pathology. A better understanding of the origin and evolution of the skin microbiome will lead to more effective prevention and treatment of pediatric skin disease.

Cutaneous microbiome effects of fluticasone propionate cream and adjunctive bleach baths in childhood atopic dermatitis.

BACKGROUND: Patients with atopic dermatitis (AD) are prone to skin infections, with microbes such as Staphylococcus aureus suspected of contributing to pathogenesis. Bleach baths might improve AD by reducing skin microbial burden. OBJECTIVE: We sought to characterize the microbiota of lesional and nonlesional skin in young children with AD and control subjects and compare changes after treatment with a topical corticosteroid (TCS) alone or TCS + dilute bleach bath. METHODS: In a randomized, placebo-controlled, single-blinded clinical trial in 21 children with AD and 14 healthy children, lesional and nonlesional AD skin was examined at baseline and after 4-week treatment with TCS alone or TCS plus bleach bath. Microbial DNA was extracted for quantitative polymerase chain reaction of predominant genera and 16S rRNA sequencing. RESULTS: At baseline, densities of total bacteria and Staphylococcus, including Staphylococcus aureus, were significantly higher at the worst AD lesional site than nonlesional (P = .001) or control (P < .001) skin; bacterial communities on lesional and nonlesional AD skin significantly differed from each other (P = .04) and from control (P < .001). After TCS + bleach bath or TCS alone, bacterial compositions on lesional skin normalized (P < .0001), resembling nonlesional skin, with microbial diversity restored to control skin levels. LIMITATIONS: The 4-week time period and/or the twice-weekly baths may not have been sufficient for additional impact on the cutaneous microbiome. More detailed sequencing may allow better characterization of the distinguishing taxa with bleach bath treatment. CONCLUSIONS: Treatment with a TCS cream suffices to normalize the cutaneous microbiota on lesional AD; after treatment, bacterial communities on lesional skin resemble nonlesional skin but remain distinct from control.

An Eastern County from an European Eastern Country-The Characteristics of Cutaneous Microbiome in Psoriasis Patients-Preliminary Results.

The cutaneous microbiome represents a topic of high interest nowadays. Multiple studies have suggested the importance of the skin microbiome in different dermatological pathologies, highlighting the possible implications of cutaneous microorganisms in either the pathogenesis or prognosis of skin maladies. Psoriasis represents a common inflammatory skin disease, with a high prevalence in the worldwide population. The role of the cutaneous microbiome in psoriasis could explain a number of pathogenic theories and treatment objectives of this incurable skin disease. Our interest in the characteristics of the cutaneous microbiome, especially in psoriatic patients who attended a tertiary dermatological centre in Galati, Romania, is reflected in our current study, of which the preliminary results are discussed in this article. Using three types of skin sampling techniques (swabs, adhesive tape, and punch biopsies), we tried to characterise the microorganisms harboured in the skin of psoriatic patients and healthy individuals. This study was performed using culture-based probes, which were analysed using MALDI-TOF mass spectrometer equipment. Our preliminary results suggested that the greatest diversity was observed in the perilesional areas of psoriatic patients. The lowest cutaneous diversity was obtained from sampling psoriatic plaques. These results are similar to other studies of the cutaneous microbiome in psoriasis. The most frequent microorganisms found in all groups studied were of the Staphylococcus species: Staphylococcus epidermidis, Staphylococcus hominis, and Staphylococcus aureus. Analysing the living environment of each individual from this study, our preliminary results suggested different results from other studies, as higher diversity and heterogenicity was observed in urban environments than in rural living areas. Regarding the differences between sexes, our preliminary results showed higher quantitative and qualitative changes in the skin microbiome of male participants than female participants, opposite to the results found in other studies of the cutaneous microbiome in psoriasis. Given these preliminary results, we can conclude that we have found important differences by studying the cutaneous microbiome of psoriatic patients and healthy control individuals from a population that, to our knowledge, has not been yet studied from this point of view. Our results showed important characteristics of the skin microbiome in an Eastern European population, where cultural and environmental living habits could influence the cutaneous microbiome.

[Impact of preservatives in topicals on the cutaneous microbiota]. / Einfluss von Konservierungsmitteln in Topika auf die kutane Mikrobiota.

Preservatives are used to stabilize topical preparations and protect the user from the influence of pathogenic microbes. After the application of a topical preparation, the matrix undergoes a metamorphosis, and by proportional evaporation of the hydrophilic phase the preservative may accumulate on the skin surface. This is believed to lead to antiseptic effects and may influence the diversity of the cutaneous microbiota. The regulation of the cutaneous microbiome and the associated influencing factors is a complex system that results in highly individualized conditions. Therefore, investigations on the influence of defined interventions are methodologically difficult. In the present proof-of-concept study, potential antiseptic effects of preservatives were investigated in a combination of in vitro and in vivo methods using microbiological culture tests. In addition, the investigations served to develop a clinical study design to answer further questions and use of an extended range of methods. The results support the hypothesis of an antiseptic effect of the tested preservatives (methyl-4-hydroxybenzoate and propyl-4-hydroxybenzoate, potassium sorbate and propylene glycol) on prominent reference bacteria, which could also be observed in clinical settings.

Influence of Sex on the Microbiota of the Human Face.

The role of the microbiota in health and disease has long been recognized and, so far, the cutaneous microbiota in humans has been widely investigated. The research regarded mainly the microbiota variations between body districts and disease skin states (i.e., atopic dermatitis, psoriasis, acne). In fact, relatively little information is available about the composition of the healthy skin microbiota. The cosmetic industry is especially interested in developing products that maintain and/or improve a healthy skin microbiota. Therefore, in the present work, the authors chose to investigate in detail the structure and composition of the basal bacterial community of the face. Ninety-six cheek samples (48 women and 48 men) were collected in the same season and the same location in central northern Italy. Bacterial DNA was extracted, the 16S rDNA gene was amplified by PCR, the obtained amplicons were subjected to next generation sequencing. The principal members of the community were identified at the genus level, and statistical analyses showed significant variations between the two sexes. This study identified abundant members of the facial skin microbiota that were rarely reported before in the literature and demonstrated the differences between male and female microbiota in terms of both community structure and composition.

The role of the pediatric cutaneous and gut microbiomes in childhood disease: A review.

OBJECTIVE: Infancy and early childhood are crucial periods in the development of the human microbiome and shape the trajectory of microbial colonization, immune system development, and systemic disease. We review the development of the skin and gut microbiomes, their connection to the immune system, and their relevance to common pediatric pathologies. FINDINGS: Beginning after birth, and likely even in utero, colonization of the skin and the gut occur in parallel, influenced by external factors. This colonization, in turn, dictates maturation of the immune system and contributes to conditions from atopic dermatitis to sepsis. Emerging literature is identifying links between the gut and skin microbiomes. CONCLUSION: The gut and skin microbiomes are associated with pediatric disease states. Immune and microbial plasticity make this unique period an ideal target for intervention. Investigating the purposeful manipulation of the pediatric microbiome may lead to novel treatment and prevention strategies.

Gut and Cutaneous Microbiome Featuring Abundance of Lactobacillus reuteri Protected Against Psoriasis-Like Inflammation in Mice.

BACKGROUND: Psoriasis is a chronic autoinflammatory skin disease, and its aetiology remains incompletely understood. Recently, gut microbial dysbiosis is found to be tightly associated with psoriasis. OBJECTIVE: We sought to reveal the causal role of gut microbiota dysbiosis in psoriasis pathogenesis and investigate the protective effect of healthy commensal bacteria against imiquimod -induced psoriasis-like skin response. METHODS: By using fecal microbial transplantation (FMT), 16S rRNA gene-based taxonomic profiling and Lactobacillus supplement, we have assessed the effect of FMT from healthy individuals on psoriasis-like skin inflammation and associated immune disorders in imiquimod-induced psoriasis mice. RESULTS: Here, by using psoriasis mice humanized with the stools from healthy donors and psoriasis patients, the imiquimod-induced psoriasis in mice with psoriasis patient stool was found to be significantly aggravated as compared to the mice with healthy donor stools. Further analysis showed fecal microbiota of healthy individuals protected against Treg/Th17 imbalance in psoriasis. Moreover, we found the gut and skin microbiome in mice receipted with gut microbiota of healthy individuals (HD) differed from those of mice receipted with gut microbiota of psoriasis patients (PSD). 16S rRNA sequencing revealed that Lactobacillus reuteri was greatly enriched in fecal and cutaneous microbiome of HD mice as compared to PSD mice. Intriguingly, supplement with Lactobacillus reuteri was sufficient to increase the expression of anti-inflammatory gene IL-10, reduce Th17 cells counts and confer resistance to imiquimod-induced inflammation on the mice with gut microbiota dysbiosis. CONCLUSION: Our results suggested that the gut microbiota dysbiosis is the potential causal factor for psoriasis and the gut microbiota may serve as promising therapy target for psoriasis patients.

The skin microbiome of Xenopus laevis and the effects of husbandry conditions.

BACKGROUND: Historically the main source of laboratory Xenopus laevis was the environment. The increase in genetically altered animals and evolving governmental constraints around using wild-caught animals for research has led to the establishment of resource centres that supply animals and reagents worldwide, such as the European Xenopus Resource Centre. In the last decade, centres were encouraged to keep animals in a "low microbial load" or "clean" state, where embryos are surface sterilized before entering the housing system; instead of the conventional, "standard" conditions where frogs and embryos are kept without prior surface treatment. Despite Xenopus laevis having been kept in captivity for almost a century, surprisingly little is known about the frogs as a holobiont and how changing the microbiome may affect resistance to disease. This study examines how the different treatment conditions, "clean" and "standard" husbandry in recirculating housing, affects the skin microbiome of tadpoles and female adults. This is particularly important when considering the potential for poor welfare caused by a change in husbandry method as animals move from resource centres to smaller research colonies. RESULTS: We found strong evidence for developmental control of the surface microbiome on Xenopus laevis; adults had extremely similar microbial communities independent of their housing, while both tadpole and environmental microbiome communities were less resilient and showed greater diversity. CONCLUSIONS: Our findings suggest that the adult Xenopus laevis microbiome is controlled and selected by the host. This indicates that the surface microbiome of adult Xenopus laevis is stable and defined independently of the environment in which it is housed, suggesting that the use of clean husbandry conditions poses little risk to the skin microbiome when transferring adult frogs to research laboratories. This will have important implications for frog health applicable to Xenopus laevis research centres throughout the world.

Skin Viral Infections: Host Antiviral Innate Immunity and Viral Immune Evasion.

The skin is an active immune organ that functions as the first and largest site of defense to the outside environment. Serving as the primary interface between host and pathogen, the skin's early immune responses to viral invaders often determine the course and severity of infection. We review the current literature pertaining to the mechanisms of cutaneous viral invasion for classical skin-tropic, oncogenic, and vector-borne skin viruses. We discuss the skin's evolved mechanisms for innate immune viral defense against these invading pathogens, as well as unique strategies utilized by the viruses to escape immune detection. We additionally explore the roles that demographic and environmental factors, such as age, biological sex, and the cutaneous microbiome, play in altering the host immune response to viral threats.

Allergic Contact Sensitization in Healthy Skin Differs from Sensitization in Chronic Dermatitis: Atopic, Occupational Wet Work, and Stasis Dermatitis.

The duration of cutaneous inflammation preceding sensitization influences the resulting allergic response; the innate immune system instructs the adaptive immune response. Potent allergens that function as their own irritant cause classic T helper cell type 1 skewed dermatitis. Examples include poison ivy, epoxy resin, and methylchloroisothiazolinone. Less potent allergens, such as food proteins and propylene glycol, sensitize skin affected by chronic dermatitis resulting in a T helper cell type 2 skewed response, sometimes with associated systemic contact dermatitis. Systemic contact dermatitis should therefore be suspected in patients with positive patch tests to ingested allergens in the setting of chronic dermatitis.

Therapeutic Potential of an Endolysin Derived from Kayvirus S25-3 for Staphylococcal Impetigo.

Impetigo is a contagious skin infection predominantly caused by Staphylococcus aureus. Decontamination of S. aureus from the skin is becoming more difficult because of the emergence of antibiotic-resistant strains. Bacteriophage endolysins are less likely to invoke resistance and can eliminate the target bacteria without disturbance of the normal microflora. In this study, we investigated the therapeutic potential of a recombinant endolysin derived from kayvirus S25-3 against staphylococcal impetigo in an experimental setting. First, the recombinant S25-3 endolysin required an incubation period of over 15 minutes to exhibit efficient bactericidal effects against S. aureus. Second, topical application of the recombinant S25-3 endolysin decreased the number of intraepidermal staphylococci and the size of pustules in an experimental mouse model of impetigo. Third, treatment with the recombinant S25-3 endolysin increased the diversity of the skin microbiota in the same mice. Finally, we revealed the genus-specific bacteriolytic effect of recombinant S25-3 endolysin against staphylococci, particularly S. aureus, among human skin commensal bacteria. Therefore, topical treatment with recombinant S25-3 endolysin can be a promising disease management procedure for staphylococcal impetigo by efficient bacteriolysis of S. aureus while improving the cutaneous bacterial microflora.

Common Cutaneous Bacteria Isolated from Snakes Inhibit Growth of Ophidiomyces ophiodiicola.

There is increasing concern regarding potential impacts of snake fungal disease (SFD), caused by Ophidiomyces ophiodiicola (Oo), on free-ranging snake populations in the eastern USA. The snake cutaneous microbiome likely serves as the first line of defense against Oo and other pathogens; however, little is known about microbial associations in snakes. The objective of this study was to better define the composition and immune function of the snake cutaneous microbiome. Eight timber rattlesnakes (Crotalus horridus) and four black racers (Coluber constrictor) were captured in Arkansas and Tennessee, with some snakes exhibiting signs of SFD. Oo was detected through real-time qPCR in five snakes. Additional histopathological techniques confirmed a diagnosis of SFD in one racer, the species' first confirmed case of SFD in Tennessee. Fifty-eight bacterial and five fungal strains were isolated from skin swabs and identified with Sanger sequencing. Non-metric multidimensional scaling and PERMANOVA analyses indicated that the culturable microbiome does not differ between snake species. Fifteen bacterial strains isolated from rattlesnakes and a single strain isolated from a racer inhibited growth of Oo in vitro. Results shed light on the culturable cutaneous microbiome of snakes and probiotic members that may play a role in fighting an emergent disease.

Skin bacterial diversity is higher on lizards than sympatric frogs in tropical Australia.

Animal skin acts as a barrier between the organism and its environment and provides the first line of defense against invading pathogens. Thus, skin surfaces harbor communities of microbes that are interacting with both the host and its environment. Amphibian skin bacteria form distinct communities closely tied to their host species, but few studies have compared bacterial communities between amphibians and other, non-amphibian sympatric animals. Notably, skin microbes on reptiles have gained little attention. We used next-generation sequencing technology to describe bacterial communities on the skin of three lizard species and compared them to bacteria on six cohabiting frog species in the Northern Territory of Australia. We found bacterial communities had higher richness and diversity on lizards than frogs, with different community composition between reptiles and amphibians and among species. Core bacteria on the three lizard species overlapped by over 100 operational taxonomic units. The bacterial communities were similar within species of frogs and lizards, but the communities tended to be more similar between lizard species than between frog species and when comparing lizards with frogs. The diverse bacteria found on lizards invites further questions on how and how well reptiles interact with microorganisms through their scaly skin.