1. Johns Hopkins School of Medicine, 733 N Broadway, Baltimore, MD 21205, U.S.A.
2. Department of Dermatology, Johns Hopkins Medical Institutions, 2500 Mason F. Lord, 4940 Eastern Avenue, Baltimore, MD 21224‐2780, U.S.A.
3. Department of Medicine, Infectious Diseases Division, Johns Hopkins Medical Institutions, Baltimore, MD, U.S.A.
4. Center for Biofilm Engineering, Montana State University, Bozeman, MT, U.S.A.