490 CLINICAL REPORT
ActaDV ActaDV Advances in dermatology and venereology Acta Dermato-Venereologica
Propionibacterium acnes Abundance Correlates Inversely with Staphylococcus aureus : Data from Atopic Dermatitis Skin Microbiome
Wojciech FRANCUZIK 1 , Kristin FRANKE 1 , Ralf R . SCHUMANN 2 , Guido HEINE 1 and Margitta WORM 1
1
Department of Dermatology , Venereology and Allergology , and 2 Institute for Microbiology and Hygiene , Charité Universitätsmedizin Berlin , Berlin , Germany
The microbiome may influence disease severity in atopic dermatitis . The skin of atopic dermatitis patients and healthy individuals was sampled in a standardized manner and the microbial composition analysed using next-generation sequencing . Optical density measurements were used to investigate bacterial growth under defined conditions in vitro . Lesional skin from patients with atopic dermatitis had a higher abundance of Staphylococcus aureus and reduced quantities of Propionibacterium acnes and Lawsonella clevelandensis compared with non-lesional skin . The abundance of P . acnes correlated negatively with that of S . aureus ( ρ = – 0.6501 , p < 0.0001 ). Fermentation products of P . acnes inhibited the growth of S . aureus and S . epidermidis . Serum from patients with atopic dermatitis inhibited the growth of S . aureus to a greater extent than did serum from healthy individuals . These results suggest that selective modification of the skin microbiome could potentially be used as a therapeutic strategy in atopic dermatitis .
Key words : P . acnes ; atopic dermatitis ; S . aureus ; microbiota , high-throughput nucleotide sequencing ; skin ; eczema .
Accepted Jan 29 , 2018 ; Epub ahead of print Jan 30 , 2018 Acta Derm Venereol 2018 ; 98 : 490 – 495 .
Corr : Margitta Worm , Department of Dermatology , Venereology and Allergology , Charité Universitätsmedizin Berlin , Charitéplatz 1 , DE-10117 , Berlin , Germany . E-mail : margitta . worm @ charite . de
Atopic dermatitis ( AD ) is a chronic , pruritic inflammatory skin disease with an estimated prevalence of 10 – 20 % among children in Western countries and 2 – 3 % among adults ( 1 ). A genetically determined defect in epidermal function is thought to be the initial mechanism in the pathogenesis of AD ( 2 ). This barrier defect results in increased water loss , xerosis and reactivity of immune cells to exogenous antigens , such as pollen and microbial flora . The ensuing immune reaction in the skin leads to pruritus and scratching , which further promote inflammation . Lesional overgrowth with Staphylococcus aureus has been described in several reports . S . aureus is a well-known pathogen that can increase disease severity ( 3 ) and has been found to be more frequent in patients with AD than in healthy individuals ( 4 ).
The Human Microbiome Project described the composition of the healthy skin microflora ( 5 ), and skin microbiome dysregulation has been reported previously in patients with AD ( 6 , 7 ). Mechanisms that either promote or depend on changes to the microbiome are currently of high scientific interest . It has been shown that the commensal skin microbiome impacts on local and systemic immunity ( 8 ). The lesional overgrowth of S . aureus correlates with AD flare-ups ( 9 ). S . epidermidis , which is considered a harmless skin commensal , promotes an innate immune response ( 10 , 11 ) and , moreover , inhibits the growth of S . aureus and Propionibacterium acnes ( 12 ).
The skin microbiome in healthy individuals and patients with AD with lesions in various anatomical sites was studied using an unbiased approach in order to determine whether a common form of microbial dysregulation is present in patients with AD . By analysing how skin bacteria interact with each other , the aim of this study is to elucidate the underlying mechanisms of AD and provide a basis for the development of novel therapeutic strategies for this disease .
METHODS Patient recruitment and sampling
Ethical approval for this single-centre research study was provided by the Charité Ethical Committee ( EA1 / 194 / 14 ). After obtaining written informed consent , patients with AD and healthy individuals ( 7 in each group ) were included in the study . All procedures were performed in accordance with the Declaration of Helsinki ( 13 ). The participants were recruited from the outpatient clinic of the Department of Dermatology Venereology and Allergology . The inclusion criteria for the AD group ( modified from ( 9 )) comprised a diagnosis of child-onset AD according to the criteria of Hanifin & Rajka ( 14 ); abstaining from the use of topical corticosteroids , skin disinfectants or antibiotics for at least 4 weeks ; and avoiding skin washing for 12 h prior to sampling . All participants were male , between 18 and 60 years of age , and were included after a thorough examination at the Comprehensive Allergy Center Charité .
The control group was composed of non-atopic , healthy volunteers with no personal or family history of allergic rhinitis , allergic asthma , or atopic dermatitis , with negative standard prick test results , and normal serum IgE concentrations . To allow for naïve microbial skin colonization , volunteers were excluded if they had used skin disinfectants , topical corticosteroids or antibiotics in the 4 weeks prior to sampling .
Sampling was performed according to the protocol by Oh ( 15 ). However , we enlarged the sampling area to increase DNA concentrations in the final samples . Catch-All swabs ( Epicentre , Madison , WI , USA ) were moisturized with DNAse-free water and used in 3 strictly defined locations ( antecubital fossa 40 cm 2 , interscapular region 40 cm 2 and retroauricular region 10 cm 2 ). DNA was extracted using the PowerSoil DNA Isolation Kit ( MO BIO Laboratories , Inc ., Carlsbad , CA , USA ), quantified using a BioPhotometer ( Eppendorf AG , Hamburg , Germany ) and confirmed by conventional PCR ( using 341F : CCTACgggAggCAgCAg doi : 10.2340 / 00015555-2896 Acta Derm Venereol 2018 ; 98 : 490 – 495
This is an open access article under the CC BY-NC license . www . medicaljournals . se / acta Journal Compilation © 2018 Acta Dermato-Venereologica .