Sarcocystosis among buffaloes from slaughterhouses in Nile Delta, Egypt: morphologic assessment and molecular confirmation.

Background: Sarcocystis species are coccidian protozoan zoonotic parasites of the phylum Apicomplexa. There is a large diversity of Sarcocystis species. Some of them are pathogenic and dangerous to humans, domestic, and wild animals. Cattle are common intermediate hosts. The infection of meat with different species of Sarcocystis can be serious for public health.

Aims: The current study aimed to determine the prevalence of sarcocystosis in slaughtered buffaloes in Tanta city abattoirs, Nile Delta, Egypt.

Methods: Morphological and histological examinations and a molecular study were undertaken. A total of 517 locally bred buffaloes were slaughtered in Tanta city, Egypt. Each buffalo carcass was visually inspected for the presence of Sarcocystis macrocysts. Fifty tissue samples containing suspected cysts were examined by using different techniques including histology, transmission electron microscope (TEM), and PCR.

Results: By visual inspection, the overall prevalence of suspected sarcocystosis was 26.5%. The highest infection rate was detected visually from the esophagus followed by skeletal muscles and diaphragm whereas the least was recorded in the tongue. Histological and TEM examination showed that the cysts were packed with bradyzoites separated by multiple septa. 100% of the sarcocysts diagnosed visually in the esophagus and muscles were confirmed by PCR, compared to only 25% of those detected in the tongue.

Conclusion: These results highlight the high prevalence of sarcocystosis among buffaloes in Egypt, possibly due to widespread environmental contamination by Sarcocystis oocysts. The use of molecular methods should be encouraged to confirm the identity of the suspected cysts.