Multilocus-sequence typing reveals clonality of Staphylococcus aureus in atopic dermatitis.

Abstract

Atopic dermatitis is exacerbated by Staphylococcus aureus which is capable of displacing not only the physiological microbiota, but also other strains of its own species. Analyzes of molecular characteristics and relationship of S. aureus strains present in different microniches are lacking. To determine the relationship of S. aureus isolates from the lesional skin, nonlesional skin and anterior nares of patients with atopic dermatitis using multilocus-sequence typing and review the characteristics of the dominant clones. Sixty-three individuals with active atopic dermatitis were enrolled. Ten moderate-to-severe patients (SCORAD≥25) colonized by S. aureus within all analyzed locations were included in the multilocus-sequence typing analysis. The most prevalent sequence types were 7 (10/30 strains, 33.3%), 15, and 97 (both 5/30 strains, 16.7%) all of which were associated with the expression of adhesins and toxins promoting chronic microbial dysbiosis, skin barrier damage and inflammation. Six patients (60%) were carriers of clonal S. aureus strains within all analyzed locations, three patients (30%) - within the lesional skin and nonlesional skin, and one patient (10%) - within nonlesional skin and the anterior nares. The results imply that the identified S. aureus lineages are better adapted to dominate the microbiota in atopic dermatitis. Decontaminating the identified reservoirs of S. aureus, i.e. the anterior nares and nonlesional skin, could reduce atopic dermatitis severity.