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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 #360692

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

Location: Animal Parasitic Diseases Laboratory

Title: The impact of vaccum packed dry-ageing pork on the viability of Toxoplasma gondii tissue cysts

item ALVES, BRUNA FARIAS - Universidad De Sao Paulo
item OLIVEIRA, SOLANGE - Universidad De Sao Paulo
item SOARES, HERBERT SOUSA - Universidad De Sao Paulo
item SOLANGE, MARIA GENNARI - Universidad De Sao Paulo
item CONTE-JUNIOR, CARLOS ADAM - Fluminense Federal University(UFF)
item Dubey, Jitender
item PENA, HILDA FATIMA JE - Universidad De Sao Paulo

Submitted to: Food Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/12/2019
Publication Date: 9/12/2019
Citation: Alves, B., Oliveira, S., Soares, H., Solange, M., Conte-Junior, C., Dubey, J.P., Pena, H.S. 2019. The impact of vaccum packed dry-ageing pork on the viability of Toxoplasma gondii tissue cysts. Food Microbiology. 86(2020):103331.

Interpretive Summary: Among these zoonotic pathogens, the protozoan parasite T. gondii is perhaps the most ubiquitous, having been identified in the tissues of a variety of animal hosts, including both mammalian and avian species. Toxoplasma gondii is estimated to chronically infect one third of the world’s human population, causing ocular toxoplasmosis in immunocompetent individuals and often-fatal encephalitis in the immunocompromised, as well as birth defects and mortality following vertical transmission to developing fetuses. Humans become infected postnatally by eating undercooked meat infected with T. gondii tissue cysts or by ingesting oocysts from the environment. Food safety continues to be a major concern worldwide. In the present study, authors found that T. gondii survived for 14 days in vaccum packed meat chilled at 10C. These results will be of interest to parasitologists, biologists, and microbiologists.

Technical Abstract: The present study evaluated the viability of Toxoplasma gondii tissue cysts in pork loins (m. longissimus) in dry-aged pork during 14, 21 and 28 days under controlled temperature (0ºC ± 1ºC). The pigs (n = 9) were orally infected with 3 x 103 oocysts of the T. gondii isolate TgCkBr57 (Type BrII). The right loin of each pig was aged for a predetermined period, and the left loin was kept unprocessed as a control. In Experiment 1, the loins of three pigs were aged for 14 days and then submitted to bioassays in cats and mice. In Experiment 2, the bioassay was performed in mice from the loins of six pigs, and the ageing periods were 14, 21 and 28 days. Toxoplasma gondii cysts remained viable in loins aged up to 14 days, as confirmed by bioassays in cats and mice. Viable T. gondii was not recovered by bioassays in mice from loins that were aged for 21 and 28 days. The results demonstrate that T. gondii remained viable in pork loins dry aged, vacuum packed for 14 days at controlled but not at 21 days or longer.