Biomaterial Database

Long-term persistence of Toxoplasma gondii in tissues of pigs inoculated with T gondii oocysts and effect of freezing on viability of tissue cysts in pork. 1988

J P Dubey

Livestock and Poultry Sciences Institute, Agricultural Research Service, USDA, Beltsville, MD 20705.

To study the distribution of tissue cysts in porcine tissues, 16 pigs were fed oocysts of 4 strains of Toxoplasma gondii (4 pigs/strain). Pigs were euthanatized between postinoculation days 103 and 875 and portions of 5 to 14 organs were bioassayed in mice and/or cats for T gondii. For bioassays, 50- to 100-g portions of tissue were incubated in acidic pepsin solution to free bradyzoites from cysts in parenchyma, and washed sediment from the digests of each specimen was inoculated SC into mice (6 mice/organ). For bioassays in cats, a 500-g portion or whole organ was fed to Toxoplasma-free cats (1 cat/organ). Toxoplasma gondii was recovered from tissues of 14 of the 16 pigs (from the brains of 12, hearts of 11, tongues of 10, and diaphragms of 6). Toxoplasma gondii was isolated from commercial cuts of meat from 5 infected pigs; from the arm picnic and ham of 3, Boston butt, spareribs, and tenderloin of 2, and bacon and tailbone of 1. Regarding the 4 pigs euthanatized between postinoculation days 759 and 865, cats shed T gondii oocysts after the ingestion of hearts of all 4; tongues of 3; bacons, hams, arm picnics, Boston butts, spareribs, and diaphragms of 2; and livers, kidneys, and tenderloins of 1. Toxoplasma gondii was found to be inconsistently distributed among the organs and muscles, but overall, tongue and heart were more heavily infected than were other tissues. Tissue cysts in pork were rendered nonviable at -12 C for 3 days.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D008460	Meat	The edible portions of any animal used for food including cattle, swine, goats/sheep, poultry, fish, shellfish, and game.	Meats
D002415	Cats	The domestic cat, Felis catus, of the carnivore family FELIDAE, comprising over 30 different breeds. The domestic cat is descended primarily from the wild cat of Africa and extreme southwestern Asia. Though probably present in towns in Palestine as long ago as 7000 years, actual domestication occurred in Egypt about 4000 years ago. (From Walker's Mammals of the World, 6th ed, p801)	Felis catus,Felis domesticus,Domestic Cats,Felis domestica,Felis sylvestris catus,Cat,Cat, Domestic,Cats, Domestic,Domestic Cat
D005260	Female		Females
D005506	Food Contamination	The presence in food of harmful, unpalatable, or otherwise objectionable foreign substances, e.g. chemicals, microorganisms or diluents, before, during, or after processing or storage.	Food Adulteration,Adulteration, Food,Adulterations, Food,Contamination, Food,Contaminations, Food,Food Adulterations,Food Contaminations
D005615	Freezing	Liquids transforming into solids by the removal of heat.	Melting
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D001681	Biological Assay	A method of measuring the effects of a biologically active substance using an intermediate in vivo or in vitro tissue or cell model under controlled conditions. It includes virulence studies in animal fetuses in utero, mouse convulsion bioassay of insulin, quantitation of tumor-initiator systems in mouse skin, calculation of potentiating effects of a hormonal factor in an isolated strip of contracting stomach muscle, etc.	Bioassay,Assay, Biological,Assays, Biological,Biologic Assay,Biologic Assays,Assay, Biologic,Assays, Biologic,Bioassays,Biological Assays
D013552	Swine	Any of various animals that constitute the family Suidae and comprise stout-bodied, short-legged omnivorous mammals with thick skin, usually covered with coarse bristles, a rather long mobile snout, and small tail. Included are the genera Babyrousa, Phacochoerus (wart hogs), and Sus, the latter containing the domestic pig (see SUS SCROFA).	Phacochoerus,Pigs,Suidae,Warthogs,Wart Hogs,Hog, Wart,Hogs, Wart,Wart Hog
D013553	Swine Diseases	Diseases of domestic swine and of the wild boar of the genus Sus.	Disease, Swine,Diseases, Swine,Swine Disease