Petras Prakas

The mallard duck (Anas platyrhynchos) as intermediate host for Sarcocystis wobeseri sp. nov. from the barnacle goose (Branta leucopsis)

Morphometric and DNA investigation results of Sarcocystis wobeseri sp. nov. from the barnacle goose (Branta leucopsis) and Sarcocystis sp. (cyst type IV) from the mallard duck (Anas platyrhynchos) are presented. No significant morphometric differences between the investigated Sarcocystis species were found. ITS-1, 18S rRNA, and 28S rRNA gene sequences of these species showed 100% identity. The conclusion is drawn that it is one and the same Sarcocystis species in different intermediate hosts.

Description of Sarcocystis anasi sp. nov. and Sarcocystis albifronsi sp. nov. in birds of the order Anseriformes

On the basis of the already published morphological, 18S rDNA, 28S rDNA data (Kutkienė et al., Parasitol Res 99:562–565, 2006; Parasitol Res 102:691–696, 2008; Parasitol Res 104:329–336, 2009), and ITS-1 region investigation results of sarcocysts presented in this paper, Sarcocystis albifronsi sp. nov. from the white-fronted goose (Anser albifrons) and Sarcocystis anasi sp. nov. from the mallard duck (Anas platyrhynchos) are described.

Identification of Sarcocystis rileyi from the mallard duck (Anas platyrhynchos) in Europe: cyst morphology and results of DNA analysis

Macroscopic cysts of Sarcocystis in ducks were recorded in Europe, but they were not investigated in more detail. Results of light and electron microscopy as well as 18S rDNA, 28S rDNA and ITS-1 region sequences of Sarcocystis macrocysts isolated from naturally infected mallard duck (Anas platyrhynchos) from Lithuania are presented in this paper. According to ultrastructure results, macrocysts examined corresponds to S. rileyi. Phylogenetic investigation showed S. rileyi to be the most closely related to two unnamed Sarcocystis species from anseriforms and to the S. mucosa. This is the first well-documented case of S. rileyi in Europe.

INVESTIGATION OF THE PHYLOGENETIC RELATIONSHIPS OF SARCOCYSTIS SPP. FROM GREYLAG (ANSER ANSER) AND WHITE-FRONTED (ANSER ALBIFRONS) GEESE TO OTHER CYST FORMING COCCIDIA USING 18S AND 28S rRNA GENE SEQUENCES

Based on cyst morphology, Sarcocystis cysts type I were found in one White-fronted goose (Anser albifrons) and cysts type III in one Greylag goose (Anser anser) and two White-fronted geese. Sarcocysts isolated from infected birds as intermediate host have not been previously described and are unnamed. Type III sarcocysts detected in White-fronted and Greylag geese may illustrate the case of polyhostal nature of sarcocysts when same-species parasites infest intermediate hosts of different species. The obtained partial sequences of 18S and 28S ribosomal RNA showed the highest homology for the genera Sarcocystis and Frenkelia. In the tree of phylogenetic relationships, the species involved in this study were grouped with Frenkelia microti, Frenkelia glareoli, Sarcocystis muris and Sarcocystis neurona. Analysis of the partial sequences of 18S and 28S ribosomal RNA revealed the phylogenetic and taxonomic status of the investigated Sarcocystis spp.

Identification and genetic characterization of Sarcocystis arctica and Sarcocystis lutrae in red foxes ( Vulpes vulpes ) from Baltic States and Spain

BackgroundTypically, carnivores serve as definitive hosts for Sarcocystis spp. parasites; currently, their role as intermediate hosts is being elucidated. The present study aimed to identify and molecularly characterize Sarcocystis cysts detected in striated muscle of red foxes from different populations in Latvia, Lithuania and Spain.MethodsMuscle samples from 411 red foxes (Vulpes vulpes) and 269 racoon dogs (Nyctereutes procyonoides) from Latvia, 41 red foxes from Lithuania and 22 red foxes from Spain were examined for the presence of Sarcocystis sarcocysts by light microscopy (LM). Sarcocystis spp. were identified by transmission electron microscopy (TEM) and molecular biology techniques.ResultsSarcocystis cysts were detected in 11/411 (2.7%) Latvian, 3/41 (7.3%) Lithuanian, and 6/22 (27.3%) Spanish red foxes, however, cysts were not observed in the muscles of racoon dogs. Based on LM, TEM, 18S rDNA, 28S rDNA, ITS1, cox1 and rpoB sequences, Sarcocystis arctica and Sarcocystis lutrae cysts were identified in red fox muscles from Latvia and Lithuania, whereas only S. arctica was detected in Spain. The 18S rDNA, 28S rDNA and ITS1 sequences from the 21 isolates of S. arctica from Latvia, Lithuania and Spain were identical. By contrast, two and four haplotypes were determined based on mtDNA cox1 and apicoplast rpoB sequences, respectively. Polymorphisms were not detected between the two isolates of S. lutrae from Latvia and Lithuania. Based on phylogenetic results, S. arctica and S. lutrae were most closely related to Sarcocystis spp. using predatory mammals as intermediate hosts and to Sarcocystis species with a bird-bird life-cycle.ConclusionsBased on current knowledge, the red fox and Arctic fox (Vulpes lagopus) could act as intermediate host for the same two Sarcocystis species. Molecular results suggest the existence of two genetic lineages of S. arctica, and such divergence relies on its geographical distribution but not on their intermediate host species.

Morphologic and Genetic Identification of Sarcocystis fulicae n. sp. (Apicomplexa: Sarcocystidae) from the Eurasian Coot (Fulica atra)

Abstract One morphologic type of sarcocyst was found in 26% (7/27) of Eurasian Coots (Fulica atra) and was described as Sarcocystis fulicae n. sp. using morphologic, 18S ribosomal (r)DNA, 28S rDNA, and internal transcribed spacer 1 (ITS1) analysis. By light microscope, cysts were ribbon-shaped and measured 7.3 mm in length by 116 μm wide. Histologically, the cyst wall reached up to 1.2 μm in thickness and seemed smooth. The detected sarcocysts were packed with relatively small banana-shaped bradyzoites that were 6.7×2.0 μm in size. Ultrastructurally, the cyst wall amounted to 1 μm and had many conical protrusions but seemed almost smooth in some places. The parasitophorous vacuolar membrane appeared undulating, with knob-like blebs and invaginations. The cyst wall belonged to type 1d. Morphologically, cysts of S. fulicae differed considerably from cysts of Sarcocystis atraii previously described in the same host but were indistinguishable from those of Sarcocystis corvusi, Sarcocystis lari, and Sarcocystis wobeseri, which use birds as intermediate hosts. According to the phylogenetic and ecologic data, birds of prey, mostly the Western Marsh Harrier (Circus aeruginosus) and the White-tailed Eagle (Haliaeetus albicilla), are presumed to be definitive hosts of S. fulicae.

Morphological and genetic characterisation of Sarcocystis halieti from the great cormorant (Phalacrocorax carbo)

Having examined 19 great cormorants (Phalacrocorax carbo) hunted in Lithuania, sarcocysts were found in the muscles of two birds. Sarcocysts detected were examined using light microscopy (LM), transmission electron microscopy (TEM), and 18S rDNA, 28S rDNA, ITS1, cox1, and rpoB sequence comparison. Based on the molecular analysis, mainly of the ITS1 region, sarcocysts were identified as Sarcocystis halieti. This is the first Sarcocystis species characterised in the great cormorant. Under the LM sarcocysts were ribbon-shaped, very long and thin (the largest fragment found amounted to 6.5 × 0.1 mm) with a smooth and thin (up to 1.2 μm) cyst wall. Banana-shaped bradyzoites were 7.2 × 1.9 (6.3–8.2 × 1.4–2.4) μm. Under TEM, the cyst wall was wavy, 0.8- to 1.2-μm thick. The comparison of 12 species demonstrated cox1 and rpoB to be unsuitable for the identification of Sarcocystis spp. using birds as intermediate hosts.