1. Laboratory of Virology, National Institute of Allergy and Infectious Diseases, National Institutes of Health , Hamilton, Montana , USA
2. Integrated Data Sciences Section, Research Technologies Branch, Division of Intramural Research, National Institute of Allergy and Infectious Disease, National Institutes of Health , Bethesda, Maryland , USA
3. Rocky Mountain Veterinary Branch, National Institute of Allergy and Infectious Diseases, National Institutes of Health , Hamilton, Montana , USA