Submitted to: Veterinary Parasitology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: October 8, 2006
Publication Date: January 15, 2007
Citation: Jenkins, M.C., Parker, C.C., Hill, D.E., Pinckney, R.D., Dubey, J.P. 2007. Neospora caninum detected in wild rodents. Veterinary Parasitology. 143:161-165.
Interpretive Summary: Bovine neosporosis is a reproductive disease of cattle caused by the protozoan parasite Neospora caninum. The disease is a major cause of abortion in dairy cattle worldwide. Although several groups are developing a vaccine against this disease, another method of control is to prevent exposure of cows to the parasite stage that is shed by dogs and coyotes. The purpose of the present study was to determine if wild rodents, such as mice and rats, harbor the parasite, and thus may serve as a source of the parasite to canines. Wild rats and mice were trapped, and brain tissue from these rodents were assayed for the presence of N. caninum using a sensitive molecular method. Nearly 10% of wild mice and 30% of wild rats were found to contain detectable levels of the parasite. This work indicates that wild rodents may serve as a source of N. caninum, and may play a role in the epidemiology of this parasitic disease.
The role of rodents in the epidemiology of neosporosis was investigated by assaying brain tissue of wild mice and rats for Neospora caninum. Both mouse and rat brain tissue were extracted for total DNA, and subjected to two different N. caninum-specific nested PCR assays. A portion of brain tissue from the mice and rats were also assayed for N. caninum in gamma-interferon knockout mice. Of the 105 wild mice tested, ~ 10% were positive in the for N. caninum-specific PCR assays. Of the 242 rats tested, ~ 30% were positive in both assays. Although mice and rats were shown to harbor N. caninum by PCR testing, clinical signs of N. caninum infection were not observed nor were N. caninum parasites recovered from gamma-interferon knockout mice inoculated with the rodent brain tissue.