Enterotoxin Gene Cluster and selX Are Associated with Atopic Dermatitis Severity-A Cross-Sectional Molecular Study of Staphylococcus aureus Superantigens.

Staphylococcus aureus superantigens (SAgs) have been reported to aggravate atopic dermatitis. However, comprehensive analyses of these molecules in multiple microniches are lacking. The present study involved 50 adult patients with active atopic dermatitis. S. aureus was isolated from the lesional skin, nonlesional skin, and anterior nares. Multiplex-PCR was performed to identify genes encoding (1) selX (core genome); (2) seg, selI, selM, selN, selO, selU (enterotoxin gene cluster, EGC); and (3) sea, seb, sec, sed, see, tstH (classic SAgs encoded on other mobile genetic elements). The results were correlated to clinical parameters of the study group. selx and EGC were the most prevalent in all microniches. The number of SAg-encoding genes correlated between the anterior nares and nonlesional skin, and between the nonlesional and lesional skin. On lesional skin, the total number of SAg genes correlated with disease severity (total and objective SCORAD, intensity, erythema, edema/papulation, lichenification and dryness). Linear regression revealed that AD severity was predicted only by selx and EGC. This study revealed that selX and EGC are associated with atopic dermatitis severity. Anterior nares and nonlesional skin could be reservoirs of SAg-positive S. aureus. Restoring the physiological microbiome could reduce the SAg burden and alleviate syndromes of atopic dermatitis.

The Propensity to Form Biofilm in vitro by Staphylococcus aureus Strains Isolated from the Anterior Nares of Patients with Atopic Dermatitis: Clinical Associations.

BACKGROUND: Atopic dermatitis is a chronic inflammatory dermatosis with complex pathogenesis. The skin microbiome in atopic dermatitis is dominated by Staphylococcus aureus which shows the ability to produce biofilm. OBJECTIVES: The aim of this work was to assess the influence of S. aureus biofilm on the course of atopic dermatitis. METHODS: Disease severity was evaluated based on the SCORAD index in 56 adult patients with atopic dermatitis. Microtiter plate assay of the propensity to form biofilm was performed on S. aureus strains isolated from the anterior nares, lesional skin, and nonlesional skin. Microbiological results were correlated to the clinical parameters and total IgE concentration. RESULTS: Biofilm-producing strains of S. aureus were identified in 76.3% (29/38) and 79.1% (34/43) of samples from the anterior nares and lesional skin, respectively (p > 0.05), and in 48.5% (16/33) of samples from nonlesional skin (p < 0.03). Patients colonized by biofilm-producing strains of S. aureus within the anterior nares showed statistically higher mean values of total and objective SCORAD and its components (extent, dryness), and of the largest extent of skin lesions during the flares in the last year when compared to patients colonized by non-biofilm-producing strains. Carriage of biofilm-producing S. aureus on lesional skin was associated with higher mean values of the extent of skin lesions during stable periods of the disease. CONCLUSIONS: The results of this study may suggest a relationship between the production of biofilm by S. aureus strains colonizing the anterior nares and the course of atopic dermatitis. Biofilm seems crucial for dispersal and persistent colonization of large areas of the skin by this pathogen. Destruction of S. aureus biofilm could positively affect the course of atopic dermatitis.

Nasal Colonization by Staphylococci and Severity of Atopic Dermatitis.

BACKGROUND: Skin colonization by Staphylococcus aureus (SA) correlates with increased severity of atopic dermatitis (AD). The role of nasal SA carriage and coagulase-negative staphylococci (CNSs) in AD is unclear. OBJECTIVE: The aim of this study was to assess the influence of colonization of lesional/nonlesional skin and the anterior nares by SA and CNSs on AD severity in 63 adult patients. METHODS: Disease severity was assessed with SCORAD index. The total immunoglobulin E (IgE) concentration was determined using the enzyme-linked immunosorbent assay method. The prevalence and abundance of staphylococci were assessed with the combination of bacterial culture and mass spectrometry. RESULTS: The prevalence values of SA within the skin (lesional/nonlesional) and anterior nares were 79.4%/61.9% and 69.8%, respectively (vs 5.6% and 13.9%, respectively in controls, P < 0.0001). The carriage of CNSs in all niches was associated with lower mean IgE concentration (1164.66 ± 1010.36 vs 1762.99 ± 1059.15, P < 0.0213; 1166.9 ± 1006.4 vs 2152.7 ± 759.2, P < 0.0063; 1022 ± 1100 vs 1925 ± 880.8, P < 0.0044, respectively). The abundance of SA correlated with the extent of skin lesions and total IgE (ρ = 0.42, P = 0.0007; ρ = 0.488, P < 0.0001; ρ = 0.312, P < 0.2; and ρ = 0.402, P = 0.0007; ρ = 0.403, P < 0.002; ρ = 0.287, P < 0.03, respectively). CONCLUSIONS: Atopic dermatitis severity correlates with both cutaneous and nasal colonization by SA. Staphylococcus aureus seems to promote TH2-type response, whereas CNS probably limits this process. Preventive measures within the anterior nares should be considered for AD patients.

Is Itch Intensity in Atopic Dermatitis Associated with Skin Colonization by Staphylococcus aureus?

BACKGROUND: Atopic dermatitis (AD) is a highly pruritic skin condition of unclear pathogenesis. Patients with AD are predisposed to colonization by Staphylococcus aureus due to deficiencies in the mechanical and immunological functions of the skin barrier. Recent studies indirectly show that S. aureus may aggravate disease flares in AD. AIMS: The aim was to assess the relationship between S. aureus skin colonization and itch intensity in patients with AD. MATERIALS AND METHODS: The SCORAD index components reflecting itch intensity (excoriations, subjective evaluation of pruritus, and sleep loss) were assessed in 33 adult patients with AD. Swabs were taken from lesional and nonlesional skin. The prevalence and abundance of S. aureus were assessed. Statistical analysis was performed to correlate the microbiological results with the clinical parameters. The control group consisted of 36 healthy volunteers. RESULTS: Lesional and nonlesional skin showed a high frequency of S. aureus colonization when compared with controls (81.8% and 57.6% vs 5.6%, respectively, P < 0.0001). The mean concentration (points) of S. aureus was 2.01 ± 1.25, 1.06 ± 1.14, and 0.11 ± 0.46, respectively (P < 0.0001). S. aureus abundance on lesional/nonlesional skin positively correlated with excoriations and sleep loss (rho = 0.69, P < 0.00001; rho = 0.44, P < 0.01; rho = 0.41, P < 0.02; and rho = 0.34, P < 0.05, respectively). The mean values of excoriations were higher in patients colonized by S. aureus than in patients without S. aureus carriage. CONCLUSION: S. aureus skin colonization may be one of the factors aggravating itch in AD. It may be hypothesized that restoring the natural composition of the skin microbiome may reduce pruritus intensity.

Can evaluation of specific immunoglobulin E serum concentrations of antibodies to aeroallergens in atopic dermatitis patients replace skin prick tests method in clinical practice?

INTRODUCTION: Positive skin prick tests (SPT) results with protein allergens are the minor Hanifin and Rajka's atopic dermatitis (AD) criterion. In adults, they mainly concern aeroallergens. The inflammation of skin often prevents SPT, but does not exclude the assessment of serous specific immunoglobulin E (sIgE) concentrations. AIM: To assess usefulness of testing AD patients to aeroallergens with SPT and sIgE concentrations, and the correlation of these results and the clinical AD course. MATERIAL AND METHODS: In 286 AD patients, total IgE and sIgE (14 aeroallergens) were measured. SPTs were performed with 17 aeroallergens. The AD severity was determined depending on the concurrent co-existence of asthma, allergic rhinitis, extensive skin flares and severe itching. RESULTS: 59.1% and 66.1% of patients have had positive results of sIgE and SPT, respectively (p > 0.05). The concentration of total IgE has positively correlated with the number of positive sIgE results (rho = 0.588, p < 0.001) and their intensity (rho = 0.592, p < 0.001). Among the patients with at least one high positive sIgE score, severe AD patients have been dominant (59.8% vs. 40.2%, p < 0.04). Among the patients with positive results without any high scores, the percentages are 21.6 and 78.4, respectively (p < 0.001). CONCLUSIONS: The compatibility of SPT results and IgE concentrations indicates that the two methods equally assess aeroallergy in AD patients. The assessment of sIgE concentrations is especially advisable in patients with an elevated total IgE level. The obtained results may suggest that presence of a high specific IgE level of antibodies to aeroallergens may be the factor predicting a severe clinical AD course.