Sarcocystis Species Richness in Sheep and Goats from Lithuania

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.

Keywords: Sarcocystis; cox1; intermediate host-specificity; microscopy; phylogeny; small ruminants.

Figure 1

Light microscopy morphology of S. capracanis excised from the oesophagus of a goat. Fresh preparations. (a) An elongated, spindle-shaped fragment of sarcocyst. (b) A portion of sarcocyst wall with finger-like protrusions to which arrow is pointed. (c) Banana-shaped bradyzoites.

Figure 2

The phylogenetic tree of some Sarcocystis spp. using cox1 sequences and Bayesian methods, displaying the placement of new variant Sarcocystis sp. OaLT1 from sheep detected in the present study. The tree was rooted on S. truncata. Percentage posterior probability values higher than 50, 70, and 95 were presented in red, turquoise, and indigo, respectively.