Sarcocystis Species Richness in Sheep and Goats from Lithuania

SIMPLE SUMMARY: Protozoan parasites of the genus Sarcocystis are characterized by a mandatory two-host, prey–predator life cycle. Several Sarcocystis species are known to form macroscopic or microscopic sarcocysts in the muscle tissues of domestic sheep and goats. It has been long considered that Sarcocystis species parasitizing farm animals are specific to intermediate hosts. However, some studies have recently reported the unexpected detection of Sarcocystis species in animals that are not considered to be their canonical hosts. In the current investigation, muscle samples of sheep and goats from Lithuania were molecularly tested for species previously described in such hosts and for other non-canonical Sarcocystis spp. Based on DNA sequence analysis, along with canonical Sarcocystis species present in their respective hosts, non-canonical (atypical) species, such as S. capracanis and S. morae, were detected in sheep, while S. arieticanis and S. tenella were found in goats. Possible explanations of the obtained results are discussed. ABSTRACT: Contradictory data is available on the intermediate host specificity of Sarcocystis spp. in farm animals. Therefore, the current work aimed at molecularly testing samples of sheep and goats reared in Lithuania to identify Sarcocystis species described in other intermediate hosts but suspected to be non-canonical parasites to these small ruminants. For this purpose, muscle samples from 47 domestic sheep and nine goats were examined. Sarcocystis species were identified using direct and nested PCR targeting cox1 and sequencing of positive amplified products. Along with the detection of the canonical Sarcocystis spp. in their respective intermediate hosts, the DNA of S. capracanis and S. morae was detected in sheep, although these species were previously thought to be specific to goats and deer, respectively. In addition, DNA from S. arieticanis and S. tenella was found in goats, even though these two species were believed to be sheep-specific. Notably, under light microscopy, only sarcocysts of S. capracanis specific to goats were observed. Thus, future research on the life cycle and host-specificity of Sarcocystis spp. examined is warranted.