Sarcocystis are protozoan parasites characterised by an obligatory prey-predator two-host life cycle. Sarcocysts are formed mainly in muscles of intermediate hosts, while sporocysts develop in small intestine of definitive host. In the period of 2015-2018, having examined leg muscles of 46 herring gulls in Lithuania, sarcocysts were detected in 12 birds (20.1%). Sarcocystis spp. were characterized using light microscopy (LM) and first internal transcribed spacer (ITS1) region sequences analysis. By LM, one morphological type of sarcocyst was distinguished. Sarcocysts were microscopic, ribbon-shaped, had smooth and thin (about 1 μm) cyst wall, and contained banana-shaped bradyzoites. Based on molecular analysis, four Sarcocystis species, S. wobeseri, S. lari, S. halieti and S. columbae were identified. It should be noted that it was impossible to distinguish Sarcocystis species detected by LM. Species identified in the herring gull were previously found in birds of families Anatidae, Columbidae, Laridae and Phalacrocoracidae. Thus, Sarcocsytis species using the herring gull as intermediate host are not host specific. Furthermore, it was demonstrated that one infected bird can harbour morphologically indistinguishable Sarcocsytis species. In conclusion, we recommend examining several Sarcocsytis isolates from one bird of genus Larus.
MOLECULAR IDENTIFICATION OF SARCOCYSTIS SPECIES IN MUSCLES OF THE HERRING GULL (LARUS ARGENTATUS) IN LITHUANIA
Evelina Juozaitytė-Ngugu1, Dalius Butkauskas1, Petras Prakas1
1 Institute of Ecology, Nature Research Centre, Akademijos St. 2, Vilnius, LT-08412, Lithuania