Sarcocystis infection in beef and industrial raw beef burgers from butcheries and retail stores: A molecular microscopic study

Sarcocystis is a genus of eucoccidian parasites, which globally infects humans and various animals. In addition to economic losses in livestock industries, the parasite is a zoonosis that infects humans through contaminated beef and pork with the parasite sarcocysts. Therefore, this study was carried out to assess Sarcocystis contamination in beef and industrial raw beef burger samples from butcheries and retail stores in Tehran, Iran. Overall, 180 samples of 90 beefs and 90 raw industrial beef burgers with at least 80% meat were randomly collected in Tehran, Iran. Samples were studied microscopically after peptic digestion. Furthermore, sample genomic DNAs were used in conventional polymerase chain reaction (PCR) to amplify approximately 900-bp fragments from 18S ribosomal DNA. Of 180 samples, 170 samples (94.4%) were microscopically and 161 samples (89.44%) were molecularly positive for Sarcocystis spp. Eucoccidial DNA fragments were detected in 161 samples (89.4%), including 78 (86.6%) beef and 83 (92.2%) beef burger samples. No significant differences were found between the beef and beef burger infestations by Sarcocystis bradyzoites using statistical analysis (P > 0.05). Statistically significant differences were seen between the sample type and the intensity of parasites in samples (P = 0.003). Furthermore, differences between the conventional PCR results (positive/negative) and the intensity of parasites in samples were statistically significant (P < 0.001). The considerable prevalence of Sarcocystis spp. in beef and beef burger samples reflects high transmission of the parasite in meat producing cattle, which is important due to food hygiene. Although the most prevalent bovine species, S. cruzi, is not a zoonosis, it is highly recommended to follow guidelines on the parasite transmission prevention due to the existence of S. hominis as a zoonotic bovine species.