1. Department of Veterinary and Biomedical Sciences, South Dakota State University, Brookings, SD 57007, USA
2. Division of Basic Biomedical Sciences, Sanford School of Medicine, The University of South Dakota, Vermillion, SD 57069, USA
3. Department of Biology/Microbiology, South Dakota State University, Brookings, SD 57007, USA
4. Division of Infectious Diseases, Department of Internal Medicine, Department of Molecular Microbiology, Department of Pathology and Immunology, Washington University School of Medicine, St Louis, MO 63110, USA
5. Newport Laboratories, Worthington, MN 56187, USA
6. Department of Infectious Diseases, St Jude Children’s Research Hospital, Memphis, TN 38105, USA