Staphylococcus Aureus-Culture Positivity Observed In Adults With Atopic Dermatitis Is Most Indicative Of An Increased Absolute and Relative Abundance Of S. Aureus and Not Reduced Biodiversity
Sunday, March 4, 2018
South Hall A2 (Convention Center)
Takeshi Yoshida, PhD, Alex Grier, Ann Gill, Anthony Corbett, Mike P. Cahill, Alexandre Lockhart, Eric Simpson, MD MCR, Mark Boguniewicz, MD FAAAAI, Jon M. Hanifin, MD FAAAAI, Anna De Benedetto, MD, Gloria L. David, PhD, Donald Y. M. Leung, MD PhD FAAAAI, Patrick M. Schlievert, PhD, Steven R. Gill, PhD, Lisa A. Beck, MD FAAAAI
RATIONALE: Subjects with atopic dermatitis (AD) are susceptible to Staphylococcus aureus (S. aureus; SA) colonization. The Atopic Dermatitis Research Network performed a cross-sectional AD study to better characterize subjects with (ADSA+) and without (ADSA-) skin SA-culture positivity.

METHODS: We utilized four different methods to quantify and characterize SA from nonlesional (NL) and lesional (L) swabs of 48 ADSA+ and 44 ADSA- adults. We obtained: SA-culture positivity from swabs cultured for 48hrs on non-selective blood agar, SA abundance determined by qPCR of the SA-specific thermonuclease gene, V1-V3 16S rRNA analysis of gDNA, and metagenome analysis of (n=22) matched 16S NL and L samples from ADSA+ and ADSA-.

RESULTS: SA abundance was highly variable with greater mean expression in ADSA+ than ADSA- (p<0.02; at NL or L site) but no difference between NL and L sites within each group. Microbiome analysis revealed similar levels of taxa diversity (by Chao1, Shannon’s diversity, phylogenetic diversity whole tree or Strong’s dominance index) between ADSA+ and ADSA-. Nevertheless, SA distribution was much greater in ADSA+ than ADSA- skin sites (p<0.0001). Preliminary metagenome analysis identified three viral genera, beta- and gamma-papillomavirus and Molluscipoxvirus, among the top 10 most abundant taxa in 59% (n=13) of AD subjects.

CONCLUSIONS: Our cross-sectional study demonstrates that adult AD subjects with (ADSA+) or without S. aureus-culture positivity (ADSA-) differ most notably in their absolute and relative quantity of S. aureus whereas microbial biodiversity was not different. Additionally, we found that 3 viral genera were remarkably common in the skin of our AD subjects.