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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 #361861

Research Project: Detection and Control of Foodborne Parasites for Food Safety

Location: Animal Parasitic Diseases Laboratory

Title: Generation of Toxoplasma gondii and Hammondia hammondi oocysts and purification of their sporozoites for downstream manipulation

item SOKOL, SARAH - University Of Pittsburgh
item WONG, SHEEN - University Of Pittsburgh
item BOYLE, JON - University Of Pittsburgh
item Dubey, Jitender

Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: 11/6/2019
Publication Date: 11/23/2019
Citation: Sokol, S.L., Wong, S., Boyle, J.P., Dubey, J.P. 2019. Generation of Toxoplasma gondii and Hammondia hammondi oocysts and purification of their sporozoites for downstream manipulation. In: Tonkin, C., editor. Toxoplasma gondii: Methods in Molecular Biology. Humana, New York, NY. p. 81-98.

Interpretive Summary: Toxoplasmosis, caused by the single celled parasite, Toxoplasma gondii, continues to be a public health problem worldwide. This parasite infects all warm-blooded hosts, including humans. It causes mental retardation and loss of vision in children, and abortion in livestock. The ingestion of food and water contaminated with resistant stage of the parasite, the oocyst, is a major mode of transmission of this parasite. Of all the hosts infected, only cats are known to excrete oocysts in feces. Cats can excrete millions of oocysts after eating an infected prey, such as a mouse or a bird. Oocysts can survive outdoors for months and they are highly infectious to humans. Prevention of T. gondii infection in food animals is essential for reducing infection in humans. Hammondia hammondi is a coccidian most closely related to T. gondii and sharing genes and antigens. In this paper the authors present step by step procedures to isolate and purify oocysts of these parasites. The paper will be of interest to biologists, and parasitologists.

Technical Abstract: Toxoplasma gondii tachyzoites and bradyzoites are studied extensively in the laboratory due to the ease with which they can be cultured. In contrast oocysts and the sporozoites within them are more difficult to work with, in that cat infections are required for their generation and isolating sporozoites requires a laborious excystation procedure. More over some parasite species such as Hammondia hammondi are obligately heteroxenous and require passage through a cat for completion of the life cycle. There is no debate that there is great value in studying this important life cycle stage, and so we present here a detailed description of the current protocols used in our laboratories to generate and isolate T. gondii and H. hammondi oocysts, and to excyst and purify the sporozoites within them for use in downstream experimental applications.