Submitted to: Journal of Parasitology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 2/6/2004
Publication Date: 3/6/2004
Citation: Dubey, J.P., Sreekumar, C., Miska, K.B., Hill, D.E., Vianna, M.C., Lindsay, D.S. 2004. Molecular and biological characterization of Hammondia heydorni-like oocysts from a dog fed hearts from naturally-infected white-tailed deer (Odocoileus virginianus). Journal of Parasitology. 90:1174-1176. Interpretive Summary: Hammondia Heydorni is a single-celled parasite of livestock. Dogs are its main reservoir hosts. Scientists at the Beltsville Agricultural Research Center report this parasite in the white-tailed deer for the first time and distinguish it from the closely related parasite, Neospora cannium. The results will be of interest to biologists, parasitologists and veterinarians.
Technical Abstract: : Neospora caninum and Hammondia heydorni are morphologically and phylogenetically related coccidians that are found in dogs. Though there is serological evidence of N. caninum infection in the white- tailed deer (Odocoileus virginianus), the parasite has not been yet isolated from the tissues of this host. In an attempt to isolate N. caninum from deer, hearts from 4 deer with antibodies to N. caninum were fed to 2 dogs. One of these dogs shed unsporulated oocysts 12-14 µm in diameter. Sporulated oocysts were not infective to Mongolian gerbils (Meriones ungulatus), and DNA isolated from these oocysts was not amplified using N. caninum-specific primers. However, positive amplification with the H. heydorni-specific ITS-1 primers and common toxoplasmatiid ITS-1 primers confirmed the presence of H. heydorni DNA in the samples. The oocysts were considered to be H. heydorni based on their morphology, biology, and molecular characteristics. This is the first record of a H. heydorni-like parasite in the white- tailed deer.