Principle Investigator: Andrew Herr, PhD

Andrew Herr, PhD, Cincinnati Children's.Atopic dermatitis (AD) is a skin condition that leads to recurring, itchy and inflamed patches on the skin. Not only is this condition painful and irritating, but it also often leads to the development of other, more life-threatening allergic conditions such as asthma. For many years, it has been clear that the skin of patients with AD was colonized with the bacterium Staphylococcus aureus, and we now know that these bacteria secrete factors that exacerbate the symptoms of AD.

Staphylococcus bacteria can be a real challenge to treat due to their ability to form biofilms, which are specialized bacterial colonies that hold together tightly and become resistant to antibiotics or immune responses. Another staphylococcal bacterial species, S. epidermidis, is normally found on healthy human skin and generally acts to suppress colonization by pathogens. However, the Herr lab has recently discovered that under some conditions, S. epidermidis can cooperate with S. aureus to form robust mixed-species biofilms. We hypothesize that such cooperation between S. epidermidis and S. aureus may be important for the development of AD and the progression to other allergic conditions such as asthma.

In this project, we will analyze the skin microbiome -- meaning the distribution of all microbial species found on the skin -- of healthy children and AD patients, using shotgun sequencing. We will sample individual bacterial strains found on the skin and will investigate if the patient-derived S. aureus and S. epidermidis can form mixed biofilms, and determine the critical factors that govern this process. Finally, we will observe whether mixed staphylococcal biofilms trigger stronger responses from skin cells that would exacerbate AD symptoms.