1. Department of Microbiology, Oregon State University, 2820 SW Campus Way, Corvallis, Oregon 97331.
2. U.S. Geological Survey, Oregon Cooperative Fish and Wildlife Unit, Department of Fisheries, Wildlife, and Conservation Sciences, Oregon State University, 2820 SW Campus Way, Corvallis, Oregon 97331.
3. Department of Biomedical Sciences, Carlson College of Veterinary Medicine, Oregon State University, 700 SW 30th St., Corvallis, Oregon 97331.