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ARS Home » Northeast Area » Beltsville, Maryland (BARC) » Beltsville Agricultural Research Center » Animal Parasitic Diseases Laboratory » Research » Publications at this Location » Publication #314743

Title: The zebrafish, Danio rerio, as a model for Toxoplasma gondii: an initial description of infection in fish

item SANDERS, JUSTINE - Oregon State University
item MOULTON, HONG - Oregon State University
item MCLEOD, RIMA - University Of Chicago
item Dubey, Jitender
item WEISS, LOUIS - Albert Einstein College Of Medicine
item ZHOU, YING - University Of Chicago
item KENT, MICHAEL - Oregon State University

Submitted to: Biology Letters
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/1/2015
Publication Date: 5/7/2015
Citation: Sanders, J., Moulton, H., Mcleod, R., Dubey, J.P., Weiss, L., Zhou, Y., Kent, M. 2015. The zebrafish, Danio rerio, as a model for Toxoplasma gondii: an initial description of infection in fish. Biology Letters. 38:675-679.

Interpretive Summary: Toxoplasmosis, caused by the single celled parasite, Toxoplasma gondii, continues to be a public health problem worldwide. This parasites infects all warm-blooded hosts, including humans. It causes mental retardation and loss of vision in children, and abortion in livestock. There are no good medicines to treat this infection and there is no vaccine to prevent infection. Mice are commonly usedas a model to screen potential therapies. Up to now fish (or other cold blooded animals) have not been found susceptible to infection. In the present study authors were able to infect zebra fish kept at 37 0C. The advantage of the model is that these animals are small in size and whole fish could be visualized under the microscope.The results will be of interest to biologists, parasitologists, and veterinarians.

Technical Abstract: Toxoplasma gondii infects a very wide range of mammals and birds, and about one-third of humans are infected with this protozoan parasite. Chronic T. gondii infection has historically been believed to be asymptomatic; however there is now evidence that suggest an association of seropositivity with several neurologic and psychiatric disorders. While there are medicines to treat acute toxoplasmosis, there are currently no treatments for the latent form of the parasite. Currently, T. gondii in vivo research is performed mostly using murine models, which are limited by cost and the inability to perform high throughput assays. To develop an improved in vivo model, we adapted zebrafish to 37°C and injected them intraperitoneally with two strains of T. gondii at a concentration of 10 tissue cysts per fish, and observed them for 7 days post injection. Fish were examined by histology for the presence of T. gondii development. Intracellular parasites were observed in fish at 5 to7 days post injection. The pattern of infection observed was similar to that found in mammalian infection, with parasites developing in the somatic muscle, heart, liver, spleen, kidney, and brain.