| Abstract [eng] |
Sarcocystis parasites can cause significant economic losses and livestock problems by infecting reptiles, birds, mammals, or humans. Until recently, Sarcocystis species were believed to be very highly specific to the intermediate host. However, recent data has raised uncertainties regarding this assumption. It is known that the domestic sheep can act as an intermediate host for six Sarcocystis species: S. arieticanis, S. tenella, S. gigantea, S. medusiformis, S. microps, and S. mihoensis. This work aimed to identify the distribution of atypical Sarcocystis species in the muscle tissues (diaphragm, oesophagus, and heart) of sheep reared in Lithuania using nucleotide sequence analysis of the cox1 gene. To achieve this goal, three objectives were set: to identify atypical Sarcocystis species in sheep tissues, to test and optimize gDNA extraction from isolated sarcocysts in stained muscle sections, and to determine the contribution of canine predators in Lithuania to the distribution of the species identified in the present study. Muscle samples from 47 domestic sheep reared in the eastern part of Lithuania were collected from a licensed slaughterhouse and analyzed in the Molecular Ecology Laboratory of the Nature Research Centre. This work led to the first global identification of the atypical domestic sheep species S. capracanis and S. morae. After testing and optimizing the gDNA extraction method from isolated single sarcocysts, only sarcocysts of the widespread sheep-specific species S. arieticanis and S. tenella were detected. By identifying the role of the three Canidae members found in Lithuania in distribution Sarcocystis parasites, new definitive hosts have been documented for Sarcocystis species parasitising sheep as intermediate hosts. For the first time, it has been established that the red fox can be the definitive host of S. arieticanis and S. morae, and the grey wolf is the definitive host of S. arieticanis and S. tenella. It is also the first documentation in the world that the raccoon dog can spread S. morae and S. tenella parasites. |
