Sarcocystis parazitų nustatymas graužikuose naudojant molekulinius metodus /

• Main Author: Rakauskaitė, Paulina
• Format: Bachelor Thesis
• Language: Lithuanian; English
• Published: Institutional Repository of Vilnius University 2022
• Subjects: Microtus arvalis
• Online Access: https://repository.vu.lt/VU:ELABAETD192980110&prefLang=en_US

Members of the genus Sarcocystis are worldwide distributed protozoan parasites. Currently, over 220 species of Sarcocystis are known to infect reptiles, birds and mammals. These parasites are characterised by an obligatory two-host prey-predator life cycle. Asexual multiplication with a formation of sarcocysts in muscles or CNS occur in the intermediate host, and sexual stages with a formation of oocysts/sporocysts develop in the definitive host. Some of Sarcocystis species are harmful to domestic and wildlife animals. The high Sarcocystis species diversity was disclosed in rodents. It is known that rodents act as intermediate hosts of about 40 Sarcocystis species. The last research on Sarcocystis parasites in rodents was performed in Lithuania 20 years ago. Morphologically Sarcocystis species are described and differentiated in the intermediate host. However, it is difficult to detect Sarcocystis in rodents due to the low prevalence of these parasites and the small amount of muscle material. Morphological analysis commonly is insufficient for the discrimination of Sarcocystis species in closely related hosts. Besides, there is a lack of molecular studies on Sarcocystis parasites in rodents. Therefore, molecular methods for the identification of Sarcocystis species in rodents should be developed. In all 435 rodents, 129 Apodemus flavicolis, 170 Mictorus arvalis, 61 Mictorus glareolus, 60 Apodemus agrarius, 10 Microtus arvalis, 5 Microtus oenconomus representatives we examined. Skeletal muscles of animals were examined for the presence of Sarcocystis. In order to reduce time and financial costs, each specimen from the same location and belonging to one host species was grouped into sample consisting of 2–11 individuals. Muscle tissues were digested with pepsin, followed by DNA extraction and amplification of cox1 and 28S rRNA gene fragments using nested PCR. Multiplied fragments were sequenced and compared using nBLAST with those of various Sarcocystis species deposited in NCBI GenBank. At least 4 species were ...