Identification of Sarcocystis and Trichinella Species in Muscles of Gray Wolf (Canis lupus) from Lithuania.

Simple Summary: The gray wolf (Canis lupus) is the largest representative of the family Canidae widespread in Eurasia and North America. Sarcocystis and Trichinella parasites were previously reported in the muscles of gray wolves. Apicomplexan Sarcocystis forms sarcocysts in the muscles of intermediate hosts and develops sporocysts in the intestines of definite hosts. Members of the genus Trichinella are cosmopolitan hazardous nematodes. The species composition of these parasites in gray wolves from Lithuania has not been studied so far. We examined muscle samples from 15 gray wolves, and species of parasites were confirmed using DNA analysis methods. Microscopically, Trichinella larvae were observed in 12 animals, and sarcocysts formed by Sarcocystis spp. were noticed in four. Trichinella britovi was also identified in the examined wolves. Current data show that zoonotic T. britovi is the dominant Trichinella species in gray wolves from nearby countries. In the case of Sarcocystis, two animals harbored S. svanai, and another two individuals were infected by S. svanai and S. arctica. Future studies are needed to assess the pathogenesis of the identified Sarcocystis spp. Apicomplexan Sarcocystis and Trichinella nematodes are food-borne parasites whose life cycle is carried-out in various wildlife and domestic animals. The gray wolf (Canis lupus) is an apex predator acting as an ecosystem engineer. This study aimed to identify the species of Sarcocystis and Trichinella found in the muscles of gray wolves in Lithuania. During the 2017–2022 period, diaphragm, heart, and hind leg samples of 15 animals were examined. Microscopical analysis showed the presence of two types of Sarcocystis parasites in 26.7% of the analyzed muscle samples. Based on the sequencing of five loci, nuclear 18S rDNA, 28S rDNA, ITS1, mitochondrial cox1, and apicoplast rpoB, S. arctica, and S. svanai were identified. The current work presents the first report of S. svanai in gray wolf. Phylogenetically, S. svanai clustered together with S. lutrae, infecting various carnivorans, and S. arctica was most closely related to S. felis from domestic cats. Trichinella spp. were found in 12 gray wolves (80%). For the first time, Trichinella species were molecularly identified in gray wolves from Lithuania. Trichinella britovi was confirmed in all of the isolated Trichinella larvae using a multiplex PCR. Gray wolves in Lithuania may serve as a major source of zoonotic pathogens due to the presence of these parasites. [ABSTRACT FROM AUTHOR]