Biologic and genetic comparison of Toxoplasma gondii isolates in free-range chickens from the northern Pará state and the southern state Rio Grande do Sul, Brazil revealed highly diverse and distinct parasite populations - Dubey, J. P; Sundar, N; Gennari, Solange Maria; Minervino, A. H. H; Farias, N. A. R; Ruas, J. L; Santos, T. R. B; Cavalcante, G. T; Kwok, O. C. H; Su, C (Veterinary Parasitology, 2007)