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United States Department of Agriculture

Agricultural Research Service


item Dubey, Jitender
item Graham, D
item De Young, R
item Dahl, E
item Eberhard, M
item Nace, E
item Won, K
item Bishop, H
item Punkosdy, G
item Sreekumar, C
item Vianna, M
item Shen, S
item Kwok, Oliver
item Sumners, J
item Demarais, S
item Humphreys, J
item Lehmann, T

Submitted to: Journal of Parasitology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/20/2003
Publication Date: 11/17/2003
Citation: Dubey, J.P., Graham, D.H., De Young, R.W., Dahl, E., Eberhard, M.L., Nace, E.K., Won, K., Bishop, H., Punkosdy, G., Sreekumar, C., Vianna, M.C., Shen, S.K., Kwok, O.C., Sumners, J.A., Demarais, S., Humphreys, J.G., Lehmann, T. 2003. Molecular and biologic characteristics of isolates of toxoplasma gondii from wildlife in the united states. Journal of Parasitology 90:67-71.

Interpretive Summary: Infection by the single-celled parasite Toxoplasma gondii causes mental retardation and loss of vision in children and abortion in livestock. The role of wildlife in the transmission of T. gondii is not clear. Scientists at the Beltsville Agricultural Research Center and The Centers for Disease Control (CDC) and Prevention found that all three genetic types of T. gondii found in humans circulate in wildlife. These studies will be of interest to biologists, parasitologists and wildlife veterinarians.

Technical Abstract: Toxoplasma gondii isolates can be grouped into 3 genetic lineages. Type I isolates are considered more virulent in outbred mice, and have been isolated predominantly from clinical cases of human toxoplasmosis, whereas types II and III isolates are considered less virulent for mice and are found in humans and food animals. Little is known of genotypes of T. gondii isolates from wild animals. In the present report, genotypes of isolates of T. gondii from wildlife in the U.S. are described. Sera from wildlife were tested for antibodies to T. gondii with the modified agglutination test and tissues from animals with titers of $1:25 (seropositive) were bioassayed in mice. Toxoplasma gondii was isolated from the hearts of 21 of 34 seropositive white-tailed deer (Odocoileus virginianus) from Mississippi, 7 of 29 raccoons (Procyon lotor), 5 of 6 bobcats (Lynx rufus), and from each of the gray fox (Urocyon cinereoargenteus), red fox (Vulpes vulpes) and coyote (Canis latrans) from Georgia . Toxoplasma gondii was also isolated from 7 of 10 seropositive black bears (Ursus americanus) from Pennsylvania by bioassay in cats. All 3 genotypes of T. gondii based on SAG2 locus were circulating among wildlife.

Last Modified: 06/24/2017
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