Methods: Seventeen patients with atopic dermatitis and 6 healthy control subjects were enrolled. Skin washing fluids were obtained from the moistened gauze which loaded on the skin lesion in the cubital fossa of atopic dermatitis patients and on the same part of normal controls. After genomic DNA was extracted from the skin washing fluids, 16s ribosomal DNA was amplified using the universal primer, sequenced through the next generation sequencer, and then the sequenced data was analyzed using bioinformatics.
Results: Staphylococcus spp. was dominant in the skin from atopic dermatitis patients, while it was undetectable in the control subject skins. The mean proportion of Staphylococcus in the total bacterial DNA of atopic dermatitis patients was 68%, however that was 0% in normal controls. Additional analysis for the species of Staphylococcus spp. revealed that most of Staphylococcus spp. was Staphylcoccus aureus. The following frequent bacteria were Pseudomonas and Streptococcus spp., and their proportions were 11% and 10% in the patients vs. 2% and 1% in the controls, respectively. On the other hand, Alcaligenaceae family and Sediminibacterium spp. were the most frequent bacteria in the skin of the controls, and their proportions were 39% and 13% in the controls vs. 0% and 0% in patients, respectively.
Conclusions: Staphylcoccus aureus is the predominant colonizer in the atopic dermatitis skin through the metagenomic analysis of bacterial DNA.