Sarcocystis species identification in cattle hearts destined to human consumption in southern Brazil

Sarcocystis spp. in Romanian Slaughtered Cattle: Molecular Characterization and Epidemiological Significance of the Findings

“…Contrary to the high overall Sarcocystis infection prevalence in cattle registered in other studies (66.2%, [2]; 78.1%, [10]; 100%, [17, 18]; 41.5%, [19]; 97.4%, [20]), in our survey, a considerably lower infection level (17.9%) was recorded. However, it should be taken into account that in some another investigations, a larger amount of tissue samples were processed (e.g., [17, 19, 20]), and the registered cumulative prevalence values are the result of the screening of at least two Sarcocystis -specific tissue matrices (e.g., heart, skeletal muscle, esophagus, diaphragm, and tongue [2, 10, 18]), with different diagnosis methods (e.g., light microscopy and fresh, pepsin digestion, and transmission electron microscope examinations), under different combination forms. Likewise, in our study, the direct PCR screening of the final concentrated pellet or heart tissue of the microscopically negative samples, which may increase the detection sensitivity of Sarcocystis spp., as highlighted by Pritt et al [21], would have contributed to the diagnostic precision.…”

“…Taking these into consideration, it can be assumed that in our study, the true prevalence is underestimated. Similar to our findings, the exclusive presence or dominance of the nonzoonotic S. cruzi in cattle tissues has been genetically confirmed in other studies conducted in Brazil (78 successfully molecularly characterized samples out of 78, [17]), Republic of Korea (31/31, [15]), Malaysia (17/17, [18]), Republic of China (215/216, [19]), Argentina (24/29, [1]), Hungary (23/36, [2]), Italy (285/384, [10]), Germany (134/257, [11]), and Iran (89/90, [22]), highlighting that this species is the most prevalent in cattle worldwide. However, caution should be taken in interpreting molecular survey results because the differences in the registered Sarcocystis spp.…”

“…Likewise, in our study, the direct PCR screening of the final concentrated pellet or heart tissue of the microscopically negative samples, which may increase the detection sensitivity of Sarcocystis spp., as highlighted by Pritt et al [21], would have contributed to the diagnostic precision. Moreover, the pellet screening with a higher power objective lens (e.g., 400x), like in the case in [17], would facilitate the identification of bradyzoites resulted from the ruptured cysts, thus increasing the prevalence of infection. Taking these into consideration, it can be assumed that in our study, the true prevalence is underestimated.…”

“…The grazing farming system has a positive effect on the risk of S. cruzi infection. This observation can be sustained by the more intense perpetuation of the intermediate and definitive host relationship within the parasite's life cycle in this system, compared to the industrial one, based on the free access of cattle to infective forms of the parasites shed by definitive hosts (e.g., domestic and/or wild carnivores) [17]. Dogs excreting infective sporocysts contaminate the natural environment of grazing cattle, including feeders with silage and hay, the pasture, and water sources.…”

Survey on Sarcocystis infection in imported male cattle carcasses slaughtered at Duhok abattoir, Kurdistan region of Iraq

“…Other studies by other researchers showed low rate of infections e.g. Venu and Hafeez (2000), Gjerde (2016) and Ferreira et al (2018) who recorded 42.6% ,54.78% and 40.8% rate of infection of Brazilian, Indian and Malaysian cattle respectively.…”