The Role of Staphylococcus Aureus Types and Toxin-Producing Ability in Pediatric Atopic Dermatitis and its Association with Disease Severity

Abstract

<span style="font-family: Times New Roman;"><strong><em>Background: </em></strong>The skin of patients with atopic dermatitis has a high susceptibility to staphylococcus aureus (<em>S. aureus</em>) colonization known to produce toxins with super antigen (SAgs) activity which are a family of potent immune-stimulatory exotoxins and may aggravate AD. The aim of this research was to evaluate the role of staphylococcus aureus types and toxin-producing ability in pediatric atopic dermatitis and its association with disease severity.</span><br /> <span style="font-family: Times New Roman;"><strong><em>Materials and Methods: </em></strong>In this cross-sectional study, fifty-two patients with AD were evaluated for clinical severity of disease using severity scoring of atopic dermatitis (SCORAD) index. Swabs were taken from their skin and <em>S. aureus</em> was isolated, then the <em>mec</em>A, SCC<em>mec</em> types and agr genes besides exotoxins with super antigen properties<em>, Hla </em>and <em>TSST</em> genes were evaluated by performing polymerase chain reaction (PCR).</span><br /> <span style="font-family: Times New Roman;"><strong><em>Results: </em></strong><em>Staphylococcus aureus</em> was isolated in 38 (73.07%) out of 52 AD patients. The SCORAD index and AD severity were strongly correlated with <em>S. aureus</em> colonization (P=0.00). The staphylococcal alpha-hemolysin (<em>Hla</em>) was the predominant toxin gene found in AD patients, <em>Hla</em> was produced in 22 patients (57.9%). The toxic shock syndrome toxin-1 (<em>TSST-1</em>) gene was found in 12 (31.6%) isolates and, in 11 patients both <em>TSST-1</em> and <em>Hla </em>toxin gene were detected. There was no significant relationship between the presence of TSST1 and <em>Hla</em> gene and the severity of the disease <em>Hla</em> (P=0.11 and P=0.08, respectively).</span><br /> <strong><em><span style="font-family: Times New Roman;">Conclusion:</span></em></strong><br /> <span style="font-family: Times New Roman;">AD severity based onthe SCORAD index was strongly correlated with <em>S.aureus</em> colonization, and the most frequent super antigen gene present in <em>S. aureous</em> isolates was that coding for (<em>Hla</em>).</span>