Evaluation of the ELISA technique to search for anti-Toxoplasma gondii IgG in juices from sun dried meat

Abstract

Toxoplasmosis is an important waterborne and foodborne zoonosis, whose agent is Toxoplasma gondii, and it affects both humans and production animals. This zoonosis is cosmopolitan and its prevalence is related to the consumption of raw or undercooked meat, this habit being considered one of the main risk factors. The control of the potential transmission of toxoplasmosis by meat is relevant, especially in artisanal products such as sun dried meats, which are handcrafted and may be consumed raw or undercooked. In this study, we proposed to evaluate the presence of immunoglobulins of the IgG anti T. gondii class by an ELISA immunoassay technique, standardizing a dilution of the meat juice obtained by defrosting sun dried meat produced from the muscles of experimentally infected animals and also from sun dried meats commercialized in shops in the north of Brazil. The results showed that the potential of the meat juice as a biological material was limited in processed meats, and the test was only possible in samples that showed an optical density (OD) equal to or greater than 0.116, a range that guaranteed the presence of sufficient blood for the ELISA assay, allowing for the measurement of specific anti-T. gondii immunoglobulins. Of the 32 samples of beef obtained from cuts from experimental cattle, only 9 (28%) presented sufficient blood to be tested, as measured by an OD equal to or greater than 0.116, 7 being positive, obtained from cuts from infected experimental animals, and 2 negative, obtained from cuts from control animals. Of the 42 samples of juice from retail sun dried meat, only 6 (14.28%) presented enough blood for the tests and only one presented anti T. gondii immunoglobulins, in agreement with data from the literature. The results were promising and demonstrated the importance of developing research and new approaches in the sanitary control of food offered to the population.

Keywords:
Toxoplasmosis; Foodborne diseases; Sun-dried beef; Zoonosis; Meat juice; Food safety