1. Newport Laboratories, Inc., Worthington, Minnesota, USA
2. Department of Veterinary and Biomedical Sciences, South Dakota State University, Brookings, South Dakota, USA
3. Veterinary Diagnostic Laboratory and Department of Diagnostic Medicine and Pathobiology, Kansas State University, Manhattan, Kansas, USA
4. Department of Biochemistry and Molecular Biophysics, Columbia University, New York, New York, USA