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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 #365952

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

Location: Animal Parasitic Diseases Laboratory

Title: Distribution of toxoplasma gondii tissue cysts in shoulder muscles of naturally infected goats and lambs

item RANI, SURABHI - University Of Maryland
item MURATA, FERNANDO - Non ARS Employee
item Kwok, Oliver
item Dubey, Jitender
item PRADHAN, ABANI - University Of Maryland

Submitted to: Journal of Food Protection
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/10/2020
Publication Date: 8/1/2020
Citation: Rani, S., Cerqueira-Cezar, C., Murata, F., Kwok, O.C., Dubey, J.P., Pradhan, A. 2020. Distribution of toxoplasma gondii tissue cysts in shoulder muscles of naturally infected goats and lambs. Journal of Food Protection. 83(8):1396-1401.

Interpretive Summary: Neosporosis is a major disease of livestock, responsible for abortion storms in cattle. The causative agent, Neospora caninum, was discovered by USDA and collaborating scientists twenty years ago, but much remains to be understood about this parasite and how best to protect against it. Here, USDA scientists and collaborators completed a ground-breaking analysis of genetic and genomic variation in global samples of the parasite, discovering the parasite to be highly inbred and surmising that it has rapidly expanded, from a European origin, predominantly through unisexual mating and vertical transmission from cow to calf. This paper will be of interest to parasitologists, biologists and veterinarians.

Technical Abstract: Toxoplasmosis has been recognized as a major public health problem worldwide. The consumption of uncooked/undercooked meat infected with Toxoplasma gondii (T. gondii) tissue cysts is one of the main sources for the transmission of this parasite. Although sheep, goats, and pigs are commonly infected with T. gondii, there is little information concerning the density of T. gondii tissue cysts in naturally infected meat. Here, we investigated the concentration and distribution of viable T. gondii tissue cysts in shoulder muscles of naturally infected lambs and goats. Hearts and shoulders of 46 lambs and 39 goats from a local grocery store were tested for T. gondii infection. First, antibodies to T. gondii were determined in heart blood/clot by the modified agglutination test (MAT); 14 animals (7 lambs and 7 goats) found seropositive were bioassayed in mice in different portion sizes, 5 g, 10 g and 50 g; 6-12 replicates were performed with each sample. Viable T. gondii was isolated from shoulders of 4 (2 lambs and 2 goats) animals. The density of T. gondii, based on mouse infectivity, varied within 5 g, 10 g and 50 g samples from each shoulder. Overall, the rate of isolation of T. gondii increased with portion size of meat bioassayed. Results of the study revealed uneven distribution of tissue cysts of T. gondii in muscles of meat animals and that even small helpings (5 g and 10 g) of meat have the potential for transmission of T. gondii. To prevent T. gondii infection, care should be taken while handling raw meat, especially by pregnant women. Hands should be washed properly after handling meat and meat should be cooked thoroughly before consumption.