RESUMO
Macroscopic Sarcocystis cysts were detected in the muscles of 28 Mallards ( Anas platyrhynchos ), 1 Eurasian Wigeon ( Anas penelope ), and 1 Common Teal ( Anas crecca ) hunted in Lithuania and Finland. According to the sequences of the 18S rRNA gene, 28S rRNA gene, and ITS-1 region, the macrocysts examined from all 30 ducks belonged to Sarcocystis rileyi. This parasite was found in the Eurasian Wigeon and the Common Teal for the first time. All S. rileyi isolates examined were identical to each other and differed from 2 S. rileyi isolates previously reported from 2 Mallards from the United States only by 1 nucleotide substitution within the ITS-1 region.
Assuntos
Doenças das Aves/parasitologia , Patos/parasitologia , Variação Genética , Sarcocystis/genética , Sarcocistose/veterinária , Animais , Animais Selvagens , Teorema de Bayes , Doenças das Aves/epidemiologia , DNA de Protozoário/química , Finlândia/epidemiologia , Lituânia/epidemiologia , Dados de Sequência Molecular , Músculo Esquelético/parasitologia , Filogenia , Prevalência , Sarcocystis/classificação , Sarcocystis/isolamento & purificação , Sarcocistose/epidemiologia , Sarcocistose/parasitologiaRESUMO
Cysts of Sarcocystis species were found in 24 of 44 (54·5%) examined blackbirds (Turdus merula). Under the light microscope, only 1 morphological type of cyst was found in all birds investigated. Ribbon-shaped cysts were long (the largest fragment found amounted to 7 mm) and of different thickness (25-206 µm). A cyst wall reached up to 3·5 µm and had finger-like protrusions. Under the transmission electron microscope, a single cyst isolated from 1 blackbird was studied. The cyst wall was 2·5-4·4 µm thick, had club- or irregularly-shaped and sometimes branched protrusions that differed in size. The content of cysts was divided into large chambers by septa. Orange segment-shaped cystozoites were 6·2 × 1·4 (5·5-7·2 × 1·2-1·5) µm. This type of cyst wall has never been described in Sarcocystis species isolated from birds, thus far. The results of 18S rDNA, 28S rDNA and ITS-1 region sequences showed that S. turdusi was most closely related to S. columbae, S. calchasi, S. wobeseri, S. cornixi and Sarcocystis sp. ex Accipiter nisus parasitizing birds. Phylogenetic results suggest that predatory birds are the most probable definitive hosts of S. turdusi.
Assuntos
Doenças das Aves/parasitologia , Sarcocystis/classificação , Sarcocistose/veterinária , Aves Canoras/parasitologia , Animais , Sequência de Bases , DNA de Protozoário/genética , DNA Espaçador Ribossômico/genética , Dados de Sequência Molecular , Filogenia , RNA Ribossômico 18S/genética , RNA Ribossômico 28S/genética , Sarcocystis/genética , Sarcocystis/ultraestrutura , Sarcocistose/parasitologia , Especificidade da EspécieRESUMO
An experiment was carried out using three cubs of the arctic fox (Alopex lagopus). Twenty-five-day-old cubs were infected by feeding them with the leg muscles of the white-fronted goose (Anser albifrons) containing Sarcocystis sp. (cyst type III) cysts. Under the light microscope, the cysts were ribbon-shaped up to 4 mm long and up to 750 microm wide. On the surface of the wall (up to 2.4 microm), they had teat- or finger-like villar protrusions. Ultrastructurally, the cyst wall was a type-9 with villar protrusions (up to 2.3 microm long) different in size. The 11.4x1.7 (10.0-13.5x1.5-2.5)microm cystozoites were almost straight and shuttle-shaped. The fox cubs started shedding typical 12.0x8.0 (10.0-12.8x6.8-8.6)microm Sarcocystis sp. sporocysts on the 13th-14th days post-infection. The patent period lasted 19 days. The conclusion drawn was that the arctic fox (A. lagopus) can be one of the definitive hosts of Sarcocystis sp. (cyst type III) from the white-fronted goose.