Detection of Three Sarcocystis Species (Apicomplexa) in Blood Samples of the Bank Vole and Yellow-Necked Mouse from Lithuania.

The genus Sarcocystis is an abundant group of Apicomplexa parasites found in mammals, birds, and reptiles. These parasites are characterised by the formation of sarcocysts in the muscles of intermediate hosts and the development of sporocysts in the intestines of definitive hosts. The identification of Sarcocystis spp. is usually carried out in carcasses of animals, while there is a lack of studies on the detection of Sarcocystis species in blood samples. In the current study, blood samples of 214 yellow-necked mice (Apodemus flavicollis) and 143 bank voles (Clethrionomys glareolus) from Lithuania were examined for Sarcocystis. The molecular identification of Sarcocystis was carried out using nested PCR of cox1 and 28S rRNA and subsequent sequencing. Sarcocystis spp. were statistically (p < 0.01) more frequently detected in the bank vole (6.3%) than in yellow-necked mice (0.9%). The analysed parasites were observed in four different habitats, such as mature deciduous forest, bog, natural meadow, and arable land. Three species, Sarcocystis funereus, Sarcocystis myodes, and Sarcocystis cf. glareoli were confirmed in the bank vole, whereas only Sarcocystis myodes were found in yellow-necked mice. The obtained results are important in the development of molecular identification of Sarcocystis parasites in live animals.

Sarcocystis Species Richness in Sheep and Goats from Lithuania.

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.