1 Department of Biological Sciences, University of Quebec at Montreal, P.O. Box 8888, Succursale Centre-Ville, Montreal, QC, Canada H3C 3P8.
2 Department of Veterinary Science, University of Kentucky, 108 Maxwell H. Gluck Equine Research Center, Lexington, KY 40546-0099, USA.
3 Department of Diagnostic Medicine and Pathobiology, College of Veterinary Medicine, Kansas State University Mosier Hall K-231, 1800 Denison Avenue, Manhattan, KS 66506, USA.
4 Key Laboratory of Zoonosis of Ministry of Agriculture, College of Veterinary Medicine and State Key Laboratory of Agrobiotechnology, China Agricultural University, No. 2 Yuanmingyuan West Road, Beijing 100193, China.
5 College of Veterinary Medicine, University of Illinois at Urbana-Champaign, 2001 South Lincoln Avenue, Veterinary Medicine Basic Sciences Building, Urbana, IL 61802, USA.