Bacterial communities living on the skin of eczema patients vary with disease severity

Staphylococcus aureus (S. aureus)

This photo shows a scanning electron microscope image of Staphylococcus aureus, which is one of several suspected causative agents of eczema. Photo courtesy of the Centers for Disease Control and Prevention’s Public Health Image Library.

A new study published July 5, 2017, in Science Translational Medicine reveals that strains of the bacterium Staphylococcus aureus (S. aureus) can dominate the skin of patients with eczema. This discovery could bring clinicians one step closer to understanding possible targets for treatment.

Human skin supports hundreds of species of bacteria, many of which are innocuous or help fight off pathogenic infection. But certain species have also been linked to eczema, a skin condition that affects up to 30 percent of all children and is characterized by inflammation, redness, itchiness, drying and cracking.

Researchers from five NIH programs and Boston University’s Department of Bioinformatics collaborated to sequence the genomes of bacteria swabbed from the skin of 11 children with moderate-to-severe eczema and compared the species and strains with those living on the skin of children without the disease. In children with eczema, only species from the genus Staphylococcus were elevated, confirming previous research showing an association between Staphylococcus and eczema.

Additionally, the researchers found that single strains of S. aureus tended to predominate on the skin of children with severe eczema, though these strains were not necessarily identical from patient to patient. In contrast, diverse strains of S. epidermidis predominated on the skin of children with moderate eczema. According to Heidi Kong, M.D., M.H.Sc., Investigator in the Dermatology Branch and a lead investigator on the study, the variability in bacterial communities may help us understand why eczema symptoms and severity can differ so greatly between individuals.

Kong says the pool of children sampled in the study was very small and more testing is needed before confirming that Staphylococcus strains directly trigger eczema flare-ups. However, understanding more about the bacterial communities present and their role in the disease can help point the way to potential therapeutic targets.

Summary Posted: 07/2017