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.

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.

The impact of the presence of antithyroid antibodies on pregnancy outcome following intracytoplasmatic sperm injection-ICSI and embryo transfer in women with normal thyreotropine levels

PURPOSE

The aim of our study was to investigate the impact of anti-thyroid peroxidase antibodies (Anti-TPO) on pregnancy outcome following the in vitro fertilization and embryo transfer (IVF-ET) in general groups and in subgroups divided according to AMH level and age.

METHODS

A total of 114 patients positive for anti-thyroid peroxidase antibodies (Anti-TPO+ group) and 495 infertile women negative for anti-thyroid peroxidase antibodies (Anti-TPO- group) undergoing IVF with ICSI from April 2010 to April 2012 were analyzed retrospectively.

RESULTS

There were no significant differences in age, BMI, basal FSH, LH, AMH levels and duration of infertility between the two main groups. No significant differences in terms of the days of ovarian stimulation, estradiol level in day 8, total gonadotropin dose, number of oocytes retrieved, available embryos and blastocysts, number of embryos transferred nor in rates of fertilization, implantation, clinical pregnancy, live birth and abortion rate between two main groups were found. The only statistically significant difference among the groups with different anti-TPO antibodies levels was found in basal FSH concentration and BMI. Among the clinical outcomes of IVF with respect to the different anti-TPO levels, the only significant difference was found for the number of oocytes retrieved. Analysis of the baseline parameters in relationship to age categories and AMH levels found significant differences between women positive and negative for thyroid antibodies with respect to basal FSH and LH levels for women >37 years and for basal FSH in AMH <0.6 subgroup.

CONCLUSIONS

The present study reveals that patients with anti-TPO antibodies showed no significant differences in fertilization, implantation, pregnancy rates, live birth rates and no higher risk for miscarriage following IVF-ET when compared with those negative for anti-thyroid antibodies.