Acta Dermato-Venereologica 99-3CompleteContent | Página 11

284 INVESTIGATIVE REPORT Changes in Lesional and Non-lesional Skin Microbiome During Treatment of Atopic Dermatitis Sunyoung KWON 1 , Ji Young CHOI 2 , Jung-Won SHIN 2 , Chang-Hun HUH 2 , Kyoung-Chan PARK 2 , Mi-Hee DU 2 , Sungroh YOON 1 and Jung-Im NA 2 1 Department of Electrical and Computer Engineering, Seoul National University, Seoul, and 2 Department of Dermatology, Seoul National University Bundang Hospital, Seongnam-si, Korea The aim of this study was to evaluate changes in the skin surface microbiome in patients with atopic der- matitis during treatment. The effect of narrowband ultraviolet B phototherapy was also studied to deter- mine the influence of exposure to ultraviolet. A total of 18 patients with atopic dermatitis were included in the study. Patients were divided into 2 groups ba- sed on treatment: 1 group treated with narrowband ultraviolet B phototherapy and topical corticosteroid, and the other group treated with topical corticosteroid only. Skin swabs and high-throughput sequencing of 16S ribosomal RNA bacterial genes were performed at 3 time-points. The microbial diversity of lesional skin increased greatly after treatment. The proportion of Staphylococcus aureus showed a significant posi- tive correlation with eczema severity. In conclusion, a drastic increase in microbial diversity and decrease in S. aureus proportion were observed with eczema treatment. Narrowband ultraviolet B treatment did not exert additive effects on eczema improvement; how­ ever, it appeared to reduce the recurrence of eczema. Key words: Staphylococcus aureus; atopic dermatitis; narrow- band ultraviolet B; eczema; microbiome. Accepted Nov 20, 2018; E-published Nov 21, 2018 Acta Derm Venereol 2019; 99: 284–290. Corr: Sungroh Yoon, Department of Electrical and Computer Engineering, Seoul National University, Seoul 151-744, Korea, and Jung-Im Na, De- partment of Dermatology, Seoul National University Bundang Hospital, Seoul National University College of Medicine, 82 Gumi-ro 173 beon-gil, Bundang-gu, Seongnam 463-707, Korea. E-mails: [email protected], [email protected] T he human microbiome consists of approximately 100 trillion microbial cells, which outnumber human cells by 10 to 1. The human skin microbiome refers to the entire communities of microbes, including bacte- ria, fungi, viruses, and mites, that reside in and on the human skin. Microbiomes influence the host immunity and sometimes protect the host from colonization by pathogenic organisms. Several researchers have tried to identify the human microbiome and have developed various techniques for microbial characterization. Traditional culture-dependent microbial characterization focuses on the species that grow readily under standard culture conditions; thus, this method is limited to identifying less than 1% of bacterial species. However, the development of high-throughput doi: 10.2340/00015555-3089 Acta Derm Venereol 2019; 99: 284–290 SIGNIFICANCE The human skin microbiome refers to the entire commu- nities of microbes that reside in and on the human skin. We observed the changes in skin microbiome in patients with atopic dermatitis along with the treatment course. The 18 study participants were divided into two groups based on treatment: narrowband ultraviolet B phototherapy and topical corticosteroid group and topical corticosteroid only group. In both groups, a drastic increase in microbial diver- sity and decrease of Staphylococcus aureus proportion were observed with eczema treatment. Narrowband ultraviolet B treatment did not exert additive effects in eczema impro- vement; however, it seemed to reduce eczema recurrence. sequencing techniques and bioinformatics has facilitated culture-independent and comprehensive identification of the microbiome. Bacterial microbiome analysis takes ad- vantage of the universal presence of small-subunit (16S) ribosomal RNA gene in prokaryotes. The 16S rRNA gene plays an essential role in microbial characterization because it not only contains highly conserved regions, which facilitates PCR, but also has hypervariable regions, which can be used for phylogenetic categorization (1). High-throughput sequencing has led to numerous fin- dings concerning the human microbiome. Atopic dermatitis (AD) is a chronic, relapsing inflam- matory skin disease affecting 15–30% of children in industrialized countries (2). Patients with AD experience repetitive skin infection, and traditional culture-based studies have revealed that Staphylococcus aureus plays an important role in the pathogenesis of AD. Approx- imately 80–100% of patients with AD have S. aureus colonization, and the colonization density of S. aureus is correlated with disease severity (3, 4). Using high- throughput sequencing technologies, drastic changes in skin microbiome in AD flare have been identified (5). How­ever, how the skin microbiome changes with treat- ment and discontinuation of treatment in the lesional and non-lesional skin of the same individuals needs further study. Moreover, several patients with AD experience seasonal aggravation of eczema, but the effect of ultra- violet (UV) light on the skin microbiome remains poorly identified. In this study, bacterial16S rRNA DNA sequen- cing was performed on lesional and non-lesional skin in patients with AD, before treatment, after treatment, and This is an open access article under the CC BY-NC license. www.medicaljournals.se/acta Journal Compilation © 2019 Acta Dermato-Venereologica.