Detection of Hammondia heydorni and related coccidia (Neospora caninum and Toxoplasma gondii) in goats slaughtered in Bahia, Brazil.

Hammondia heydorni is a coccidian parasite with an obligatory two host life cycle, with dogs and foxes as definitive hosts, and a number of intermediate hosts, including goats. While infection by this parasite seems to be unassociated with any clinical signs, infection by the closely related parasites Neospora caninum and Toxoplasma gondii can result in abortion, stillbirths and low yielding in caprine herds. The aim of this work was to investigate the frequency of goats infected with H. heydorni using a nested PCR, specific to Toxoplasmatinae internal transcribed spacer 1 (ITS1) of the rDNA, followed by sequencing of the purified PCR fragments. The same molecular techniques were used to determine the frequencies of N. caninum and T. gondii-infected animals. A total frequency of 13.72% (14/102) was obtained for Toxoplasmatinae DNA in goat tissues. After sequencing the PCR products from all positive tissues, a frequency of 3.92% (4/102), 1.96% (2/102) and 7.84% (8/102) were obtained for H. heydorni, N. caninum and T. gondii, respectively. All sequences shared 98-100% identity with sequences from other strains of these coccidia present in GenBank. To the authors' knowledge, this is the first report of H. heydorni DNA in tissues from naturally infected intermediate hosts.