Correlation Between Serum 25‐Hydroxyvitamin D and Virulence Genes of Staphylococcus aureus Isolates Colonizing Children with Atopic Dermatitis

Abstract

The skin of children with atopic dermatitis (AD) is colonized with Staphylococcus aureus more frequently than that of their peers. We investigated the prevalence of skin and nares colonization by S. aureus in children with AD, the virulence genes of the isolates, and their association with allergy, AD severity, and serum vitamin D (25(OH)D). This was an observational, cross-sectional study in a sample of children diagnosed with AD in two settings in Spain. The samples were collected in 2012. Swabs from affected skin and nares were taken for microbiologic culture. The prevalence of S. aureus and presence of 17 staphylococcal virulence genes were studied using polymerase chain reaction. A total of 114 patients with a mean age of 5.7 ± 4.1 (range 3 mos to 14 yrs) were included in the study. Swabs were taken from the skin of 113 individuals with AD and from the nares of 85; 28.3% had S. aureus on the skin, which was significantly associated with positive allergen-specific immunoglobulin E antibodies and higher Scoring Atopic Dermatitis (SCORAD) scores in the multivariate analysis. The presence of virulence factors tsst-1, eta, cna, aur, and sec in cutaneous S. aureus isolates was associated with lower serum levels of 25(OH)D. S. aureus on nasal swabs correlated with its presence on the skin and was associated with lower 25(OH)D levels. In conclusion, S. aureus colonization is associated with allergy and severity in AD, whereas certain virulence genes are associated with lower serum 25(OH)D levels.

Vitamin D in atopic dermatitis, chronic urticaria and allergic contact dermatitis

“…Because AD can be worsened by an overlying bacterial infection, an observational, cross-sectional study investigated the relationship between levels of vitamin D and S. aureus virulence factors [22]. Several virulence factors, including tsst-1, eta, cna, aur, and sec, were associated with lower 25[OH]D levels, indicating that vitamin D deficiency can be associated with more virulent overlying S. aureus infections in patients with AD.…”

Vitamin D and the Pathophysiology of Inflammatory Skin Diseases

“…AD patients are susceptible to the skin colonization and infection by S. aureus , which through the production of exotoxins with supra-antigenic properties aggravates the disease. Gilaberte et al [145] have observed a significant association between low serum vitamin D levels and certain virulence genes of S. aureus in isolates of AD children suggesting some role of vitamin D deficiency in S. aureus colonization. Thus, vitamin D supplementation could be promising in reducing the cutaneous S. aureus burden in AD patients.…”

Staphylococcus Aureus Colonization and the Factors Affecting Colonization in Children with Atopic Dermatitis

“…hastalarda S.aureus kolonizasyonu olanlarda serum total IgE düzeyleri daha yüksek ölçülmüştür (24). Bir başka çalışmada ortalama serum total IgE düzeyi nazal bakteriyel kolonizasyonu olanlarda yüksek bulunmuştur ancak fark anlamlı değildir (20). Çalışmamızda sadece nazal S.aureus kolonizasyonu olanlarda serum total IgE düzeyi yüksek bulunmuştur.…”

“…Fakat sonuçlarımızın aksine, Gilaberte ve ark. (20) atopik olanlarda deride bakteriyel S.aureus kolonizasyonun daha yüksek olduğunu gösterdi. Önceki çalışmadan farklı olarak biz atopiyi DPT yöntemi ile değerlendirdik.…”

“…Bu beklediğimiz bir sonuçtu çünkü, infantil döneminde atopik dermatit olgularının sadece üçte birinde atopi tesbit edilebilmekte ve daha büyük çocuklara kıyasla polen allerjen duyarlılığı gözlenmemektedir (32). Bahsedilen çalışmada bizimkinden farklı olarak hasta yaş ortalaması daha yüksektir ve spesifik IgE ölçümü ile polen duyarlılığı olan çocuklar da atopik gruba dahil edilmiştir (20). Tüm bu nedenlerle, çalışmamızda çocuklarda nazal ve deride bakteriyel kolonizasyon ile atopi arasında istatistiksel ilişki saptanamamış olabilir.…”