The effect of UVB radiation on skin microbiota in patients with atopic dermatitis and healthy controls

A previous study using bacterial 16S rRNA gene-based clone libraries revealed that the microbiota in healthy human skin included uncultured micro-organisms, although the micro-organisms in skin exposed to disease conditions remain to be examined. To compare the profiles of skin microbiota in 13 patients with atopic dermatitis (AD) and 10 healthy controls, terminal RFLP analysis of bacterial 16S rRNA genes was applied to 23 swab-scrubbed samples from facial skin. This culture-independent analysis successfully revealed the complex bacterial members of the microbiota as peak patterns following capillary electrophoresis of terminal restriction fragments (T-RFs). Each T-RF peak reflected a micro-organism, and the micro-organism to which each peak was assigned could be identified by computer simulation of T-RF length using the nucleotide sequence data of bacterial species residing in the skin. Among 18 species detected in the study, Stenotrophomonas maltophilia was detected significantly more commonly in AD patients (5/13 for AD patients vs 0/10 for controls), whilst Dietzia maris was detected significantly more commonly in normal controls (8/10 for controls vs 2/13 for AD patients). Moreover, Streptococcus species, which are considered to be uncommon in uninfected skin, were detected in seven patients and eight normal controls. Although further studies should be undertaken to investigate the roles of these micro-organisms in AD, the microbiota were presumed to include hitherto uninvestigated bacterial species in the major population of patients with AD and of healthy controls.

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Can the Skin Microbiota of Patients Suffering from Atopic Dermatitis be Modified after Balneotherapy?

SKIN The Journal of Cutaneous Medicine ◽

10.25251/skin.1.supp.33 ◽

2017 ◽

Vol 1 ◽

pp. s34

Author(s):

S Seite ◽

D Moyal

Keyword(s):

Atopic Dermatitis ◽

Skin Microbiota

Abstract Not Available

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Skin Barrier Function in Psoriasis and Atopic Dermatitis: Transepidermal Water Loss and Temperature as Useful Tools to Assess Disease Severity

Journal of Clinical Medicine ◽

10.3390/jcm10020359 ◽

2021 ◽

Vol 10 (2) ◽

pp. 359 ◽

Cited By ~ 1

Author(s):

Trinidad Montero-Vilchez ◽

María-Victoria Segura-Fernández-Nogueras ◽

Isabel Pérez-Rodríguez ◽

Miguel Soler-Gongora ◽

Antonio Martinez-Lopez ◽

...

Keyword(s):

Atopic Dermatitis ◽

Disease Severity ◽

Water Loss ◽

Barrier Function ◽

Skin Barrier ◽

Transepidermal Water Loss ◽

Diagnostic Tools ◽

Psoriatic Skin ◽

Skin Barrier Function ◽

Healthy Controls

Multiple diagnostic tools are used to evaluate psoriasis and atopic dermatitis (AD) severity, but most of them are based on subjective components. Transepidermal water loss (TEWL) and temperature are skin barrier function parameters that can be objectively measured and could help clinicians to evaluate disease severity accurately. Thus, the aims of this study are: (1) to compare skin barrier function between healthy skin, psoriatic skin and AD skin; and (2) to assess if skin barrier function parameters could predict disease severity. A cross-sectional study was designed, and epidermal barrier function parameters were measured. The study included 314 participants: 157 healthy individuals, 92 psoriatic patients, and 65 atopic dermatitis patients. TEWL was significantly higher, while stratum corneum hydration (SCH) (8.71 vs. 38.43 vs. 44.39 Arbitrary Units (AU)) was lower at psoriatic plaques than at uninvolved psoriatic skin and healthy controls. Patients with both TEWL > 13.85 g·m−2h−1 and temperature > 30.85 °C presented a moderate/severe psoriasis (psoriasis area severity index (PASI) ≥ 7), with a specificity of 76.3%. TEWL (28.68 vs. 13.15 vs. 11.60 g·m−2 h−1) and temperature were significantly higher, while SCH (25.20 vs. 40.95 vs. 50.73 AU) was lower at AD eczematous lesions than uninvolved AD skin and healthy controls. Patients with a temperature > 31.75 °C presented a moderate/severe AD (SCORing Atopic Dermatitis (SCORAD) ≥ 37) with a sensitivity of 81.8%. In conclusion, temperature and TEWL values may help clinicians to determine disease severity and select patients who need intensive treatment.

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A Combined Analysis of Gut and Skin Microbiota in Infants with Food Allergy and Atopic Dermatitis: A Pilot Study

Nutrients ◽

10.3390/nu13051682 ◽

2021 ◽

Vol 13 (5) ◽

pp. 1682

Author(s):

Ewa Łoś-Rycharska ◽

Marcin Gołębiewski ◽

Marcin Sikora ◽

Tomasz Grzybowski ◽

Marta Gorzkiewicz ◽

...

Keyword(s):

Atopic Dermatitis ◽

Food Allergy ◽

Gut Microbiota ◽

Bacterial Species ◽

Rrna Gene ◽

Healthy Children ◽

Skin Microbiota ◽

Fecal Samples ◽

Healthy Infants ◽

Α Diversity

The gut microbiota in patients with food allergy, and the skin microbiota in atopic dermatitis patients differ from those of healthy people. We hypothesize that relationships may exist between gut and skin microbiota in patients with allergies. The aim of this study was to determine the possible relationship between gut and skin microbiota in patients with allergies, hence simultaneous analysis of the two compartments of microbiota was performed in infants with and without allergic symptoms. Fifty-nine infants with food allergy and/or atopic dermatitis and 28 healthy children were enrolled in the study. The skin and gut microbiota were evaluated using 16S rRNA gene amplicon sequencing. No significant differences in the α-diversity of dermal or fecal microbiota were observed between allergic and non-allergic infants; however, a significant relationship was found between bacterial community structure and allergy phenotypes, especially in the fecal samples. Certain clinical conditions were associated with characteristic bacterial taxa in the skin and gut microbiota. Positive correlations were found between skin and fecal samples in the abundance of Gemella among allergic infants, and Lactobacillus and Bacteroides among healthy infants. Although infants with allergies and healthy infants demonstrate microbiota with similar α-diversity, some differences in β-diversity and bacterial species abundance can be seen, which may depend on the phenotype of the allergy. For some organisms, their abundance in skin and feces samples may be correlated, and these correlations might serve as indicators of the host’s allergic state.

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Staphylococcal Communities on Skin Are Associated with Atopic Dermatitis and Disease Severity

Microorganisms ◽

10.3390/microorganisms9020432 ◽

2021 ◽

Vol 9 (2) ◽

pp. 432

Author(s):

Sofie Marie Edslev ◽

Caroline Meyer Olesen ◽

Line Brok Nørreslet ◽

Anna Cäcilia Ingham ◽

Søren Iversen ◽

...

Keyword(s):

Atopic Dermatitis ◽

Alpha Diversity ◽

Skin Microbiota ◽

Specific Primers ◽

Staphylococcus Lugdunensis ◽

Disease Symptoms ◽

Lesional Skin ◽

Staphylococcus Capitis ◽

Staphylococcus Hominis

The skin microbiota of atopic dermatitis (AD) patients is characterized by increased Staphylococcus aureus colonization, which exacerbates disease symptoms and has been linked to reduced bacterial diversity. Skin bacterial communities in AD patients have mostly been described at family and genus levels, while species-level characterization has been limited. In this study, we investigated the role of the bacteria belonging to the Staphylococcus genus using targeted sequencing of the tuf gene with genus-specific primers. We compared staphylococcal communities on lesional and non-lesional skin of AD patients, as well as AD patients with healthy controls, and determined the absolute abundance of bacteria present at each site. We observed that the staphylococcal community, bacterial alpha diversity, and bacterial densities were similar on lesional and non-lesional skin, whereas AD severity was associated with significant changes in staphylococcal composition. Increased S. aureus, Staphylococcus capitis, and Staphylococcus lugdunensis abundances were correlated with increased severity. Conversely, Staphylococcus hominis abundance was negatively correlated with severity. Furthermore, S. hominis relative abundance was reduced on AD skin compared to healthy skin. In conclusion, various staphylococcal species appear to be important for skin health.

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Changes in nano-mechanical properties of human epidermal cornified cells in children with atopic dermatitis

Wellcome Open Research ◽

10.12688/wellcomeopenres.15729.2 ◽

2020 ◽

Vol 5 ◽

pp. 97

Author(s):

Marek Haftek ◽

Maeve A McAleer ◽

Ivone Jakasa ◽

WH Irwin McLean ◽

Sanja Kezic ◽

...

Keyword(s):

Mechanical Properties ◽

Atopic Dermatitis ◽

Elastic Modulus ◽

Barrier Function ◽

Degradation Products ◽

Skin Barrier ◽

Skin Barrier Function ◽

Healthy Children ◽

Healthy Controls ◽

Strongly Correlated

Background: Impaired skin barrier is an important etiological factor in atopic dermatitis (AD). The structural protein filaggrin (FLG) plays a major role in maintenance of the competent skin barrier and its deficiency is associated with enhanced susceptibility to mechanical injury. Here we examined biomechanical characteristics of the corneocytes in children with AD and healthy controls. Methods: We recruited 20 children with AD and 7 healthy children. They were genotyped for filaggrin gene (FLG) loss-of-function mutations. Stratum corneum was collected from clinically unaffected skin by adhesive tapes. Cell stiffness (apparent elastic modulus, Ea) was determined by atomic force microscopy and filaggrin degradation products (NMF) by liquid chromatography. Skin barrier function was assessed through trans-epidermal water loss (TEWL) and disease severity by the SCORing Atopic Dermatitis (SCORAD) tool. Results: Corneocytes collected from AD patients showed a decreased elastic modulus which was strongly correlated with NMF and TEWL, but not with SCORAD. As compared with healthy controls, AD patients had reduced TEWL and NMF levels regardless of FLG mutations. NMF was strongly correlated with TEWL. Conclusion: Our findings demonstrate that AD patients have decreased corneocyte stiffness which correlates with reduced levels of filaggrin degradation products, NMF and skin barrier function. Altered mechanical properties of the corneocytes likely contribute to the loss of mechanical integrity of the SC and to reduced skin barrier function in AD.

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The Keratinocyte as a Crucial Cell in the Predisposition, Onset, Progression, Therapy and Study of the Atopic Dermatitis

International Journal of Molecular Sciences ◽

10.3390/ijms221910661 ◽

2021 ◽

Vol 22 (19) ◽

pp. 10661

Author(s):

Pamela Gallegos-Alcalá ◽

Mariela Jiménez ◽

Daniel Cervantes-García ◽

Eva Salinas

Keyword(s):

Atopic Dermatitis ◽

Complex Disease ◽

Skin Diseases ◽

Current Knowledge ◽

Immune Dysregulation ◽

Chronic Inflammatory Disease ◽

Skin Microbiota ◽

External Agents ◽

Chronic Skin ◽

Inflammatory Molecules

The keratinocyte (KC) is the main functional and structural component of the epidermis, the most external layer of the skin that is highly specialized in defense against external agents, prevention of leakage of body fluids and retention of internal water within the cells. Altered epidermal barrier and aberrant KC differentiation are involved in the pathophysiology of several skin diseases, such as atopic dermatitis (AD). AD is a chronic inflammatory disease characterized by cutaneous and systemic immune dysregulation and skin microbiota dysbiosis. Nevertheless, the pathological mechanisms of this complex disease remain largely unknown. In this review, we summarize current knowledge about the participation of the KC in different aspects of the AD. We provide an overview of the genetic predisposing and environmental factors, inflammatory molecules and signaling pathways of the KC that participate in the physiopathology of the AD. We also analyze the link among the KC, the microbiota and the inflammatory response underlying acute and chronic skin AD lesions.

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