1. Department of Microbiology, Ohio State University, Columbus, OH 43210
2. Department of Microbial Infection and Immunity, Ohio State University College of Medicine, Columbus, OH 43210
3. Department of Health and Rehabilitation Sciences, Ohio State University College of Medicine, Columbus, OH 43210
4. Department of Biomedical Sciences and Pathobiology, Virginia Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA 24060
5. Department of Microbiology, University of Washington School of Medicine, Seattle, WA 98195