The white-tailed eagle, Haliaeetus albicilla, has been involved in the life cycle of several Sarcocystis species as the intermediate and definitive host. To date, it has been supposed that the eagle might play the role as the definitive host for S. Lutrae, and, herein, we tried to elucidate it based on morphometric and molecular analyses. One out of two eagles harbored oocysts (17.0-17.4 × 11.3-11.9 μm) and sporocysts (11.3-12.3 × 8.3-9.3 μm) in the intestinal mucosa, whose sequences at 18S rRNA, 28S rRNA, ITS1, and cox1 showed similar identity (97.64-100%) to published sequences of S. lutrae from other hosts. The presence of sporulated oocysts in the lamina propria of villi confirms that S. lutrae truly infects the white-tailed eagle. The white-tailed eagle is confirmed as the definitive host of S. lutrae in the Czech Republic.

• Keywords
• Czech Republic, birds of prey, carnivores, genetic characterization, oocysts and sporocysts, protozoan, small intestine, wildlife,
• Publication type
• Journal Article MeSH

BACKGROUND: Apicomplexan parasites of the genus Sarcocystis have an obligate two-host life-cycle and comprise about 200 species, which infect different cold- and warm-blooded hosts, including humans. Recently, morphological and molecular studies of sarcocysts in broadly spread carnivore hosts have been on the rise. The description of muscular tissues infection by Sarcocystis in the raccoon dog and the common raccoon from the Czech Republic is herein presented. METHODS: During January-August 2019, 15 raccoon dogs and 1 common raccoon were examined from 5 districts (Česká Lípa, Liberec, Mladá Boleslav, Trutnov and Ústí nad Labem) of the Czech Republic. Muscle parts (diaphragm, forearm, hind-limb, tongue and heart) were examined in wet preparations under compression by light microscopy. After finding Sarcocystis sp., morphological characteristics and molecular analyses of 18S rRNA, 28S rRNA, ITS1 and cox1 loci were used to identify the species. RESULTS: Sarcocysts were detected and identified in 1 out of 15 raccoon dogs and in the single common raccoon. Preferential infection sites were diaphragm and tongue, followed by forearm and hind limb. To our knowledge, this is the first identification of microscopic sarcocysts by multi-locus genetic analysis from both host species. Molecular analyses revealed 100% similarity at 18S rRNA, 28S rRNA, and cox1 genes with S. lutrae for both hosts and 98-100% identity at the ITS1 region of the isolate from the common raccoon. CONCLUSIONS: Both widely distributed non-indigenous wild carnivores represent new intermediate host records for S. lutrae and the first report of this parasite in a member of the family Procyonidae, but still with an unknown natural definitive host. Molecular data revealed that this parasite species appears more closely related to the Sarcocystis spp. using raptorial birds as definitive hosts. Therefore, further studies aimed at its identification, including the complete life-cycle, remain necessary.

• Keywords
• Common raccoon, Czech Republic, Molecular characterization, Raccoon dog, Sarcocystis lutrae, Wildlife,
• MeSH
• Phylogeny MeSH
• Pathology, Molecular MeSH
• Raccoons parasitology   MeSH
• Genes, Protozoan MeSH
• Protozoan Infections MeSH
• Raccoon Dogs parasitology   MeSH
• RNA, Ribosomal, 18S genetics   MeSH
• RNA, Ribosomal, 28S genetics   MeSH
• Sarcocystidae classification   MeSH
• Sarcocystis classification   genetics   isolation & purification   MeSH
• Life Cycle Stages MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Geographicals
• Czech Republic MeSH
• Names of Substances
• RNA, Ribosomal, 18S MeSH
• RNA, Ribosomal, 28S MeSH