Phenotypic and pathological characterizations of different Sarcocystis species in donkeys

Abstract

This study aimed to record the prevalence of different Sarcocystis spp., demonstrate their morphological characters by laboratory, histopathological and immunohistochemical techniques, also to investigate the pathological lesions in esophagus, heart, and brain samples collected from naturally infected donkeys in Egypt. The current study identified four Sarcocystis spp. (S. bertrami, S. equicanis, S. asinus and S. fayeri) in meat samples and S. neurona in the brain of the examined donkeys. Examination of meat samples showed macroscopic tissue cysts of S. bertrami and microscopic tissue cysts of S. equicanis/S. asinus and S. fayeri. According to the thickness of the cyst wall, Sarcocystis spp. were divided into smooth thin walled S. bertrami, ciliated thin walled S. equicanis/S. asius and striated thick walled S. fayeri. Also, immunohistochemical (IHC) examination showed strong labeled schizonts and cyst wall of S. neurona, while the bradyzoites appeared negative staining. Pathological examination revealed degeneration of muscles with intermuscular edema and few mononuclear inflammatory cells, but brain tissue showed perivascular lymphocytic cuffing and satellitosis with developing schizonts. The current study concluded that the accurate recognition about Sarcocystis spp. in donkeys would be helpful in their treatment, prevention and control measures.