PURPOSE OF THE STUDY.
To identify if the normal human skin microbiome contains commensal bacteria that produce antimicrobial activity against S. aureus and if commensal loss results in the development of atopic dermatitis (AD).
The study included adults with AD and age-matched, healthy, non-AD subjects. A large number of AD subjects were culture positive for S. aureus on lesional and nonlesional skin sites.
The authors isolated coagulase-negative Staphylococcus (CoNS) species with identified antimicrobial activity against S. aureus from the skin of AD and non-AD subjects. The study identified Staphylococcus epidermidis and Staphylococcus hominis as sources of these antimicrobial peptides (AMPs). The CoNS strains were applied autologously to the lesional skin of 5 AD patients. S. aureus colonization was examined after autologous microbiome transplant.
When the CoNS strains were applied autologously to the lesional skin of AD patients, S. aureus colonization decreased.
Normal skin has CoNS that produce AMPs, which in turn inhibit overgrowth of S. aureus. Thus, some skin bacteria produce AMPs that protect against S. aureus colonization, and loss of these protective bacteria may contribute to the development of AD.
This study highlights the importance of the skin microbiome in AD. Peptides made by the skin commensal microbiome may be the first line of defense against pathogens and later AD development. The findings from this study may one day provide the framework for the prevention and treatment of AD by altering the skin bacterial flora or by developing these AMPs as topical medications.
- Copyright © 2017 by the American Academy of Pediatrics