1. Department of Veterinary Medicine, College of Veterinary Medicine, Federal University of Minas Gerais (UFMG), Belo Horizonte, MG 31275-013, Brazil.
2. Department of Biochemistry and Immunology, Institute of Biological Sciences, Federal University of Minas Gerais (UFMG), Belo Horizonte, MG 31270-901, Brazil.
3. Department of Veterinary Medicine, State University of Santa Cruz (UESC), Ilhéus, BA 45662-900, Brazil.