1. Department of Clinical Veterinary Sciences, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido 080–8555, Japan
2. United Graduate School of Veterinary Sciences, Gifu University, Gifu, Gifu 501–1193, Japan
3. Visayas State University, Visca, Baybay City 6521-A, Leyte, Philippines
4. National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido 080–8555, Japan
5. Biology Department, College of Science, De La Salle University-Manila, Taft Avenue, Manila 1000, Philippines