Occurrence and first molecular characterization of Sarcocystis spp. in wild boars (Sus scrofa) and domestic pigs (Sus scrofa domesticus) in Romania: Public health significance of the isolates

- Sarcocystis spp. prevalence in wild boars and domestic pigs of Western Romania is high.
- Sarcocystis miescheriana was the only identified species.
- Hosts older than 27 months were significantly higher (p < 0.05) infected.
- The lack of identification of S. suihominis suggests that the screened animals play a neglected role in the spreading of the zoonotic Sarcocystis infections.

Domestic and wild pigs, as intermediate hosts, can harbor tissue cysts of three Sarcocystis species namely S. miescheriana, S. suihominis and S. porcifelis. Out of them, S. suihominis is zoonotic. Romania is a country with high consumption of raw and/or undercooked traditional pork products. This fact may greatly favor the acquiring of the zoonotic Sarcocystis infections by humans, as definitive host. Based on this consideration and in order to investigate the occurrence and public health significance of Sarcocystis spp. in two western counties (Caraş-Severin and Timiş) of Romania, a total of 165 heart samples from hunted wild boars (Sus scrofa, n = 101) and home slaughtered domestic pigs (Sus scrofa domesticus, n = 64) were screened using microscopic fresh examination and molecular methods. Microscopic examination revealed the presence of sarcocysts in 60.4% of wild boars, and 23.4% of domestic pigs. Genetic characterization of isolates through the PCR-RFLP procedure, targeting the 18S rRNA gene, was successfully achieved for all microscopically positive samples, indicating the presence of a single species, S. miescheriana, in both hosts. The identity of 13 selected S. miescheriana isolates was also confirmed through sequencing. The tested hosts older than 27 months were found to be significantly higher infected (p < 0.05) with Sarcocystis than the 6 to ≤27 months age group. Although the human infective S. suihominis has not been registered, for a more reliable epidemiological picture, further molecular studies enrolling a larger number of animals and diagnosis on human intestinal Sarcocystis infections are still necessary.