Macroscopic, histological, and molecular aspects of Sarcocystis spp. infection in tissues of cattle and sheep

Abstract

The macroscopic, histological, and molecular aspects of Sarcocystis spp. were examined in the tissues of two cattle and four sheep, 16 and eight fragments analyzed respectively, condemned in the slaughterhouse. All 24 samples were collected and analyzed for detecting macrocysts and macroscopic lesions. Subsequently, subdivided for direct examination, polymerase chain reaction and histopathological examination. All sheep tissues samples had grossly white round to oval tissue cysts, ranging from 0.3 to 1 cm in diameter. In contrast, cattle tissues did not present grossly visible cysts but had randomly distributed white-yellow foci with irregular contours. All samples from cattle and sheep had microscopic cysts. In the histological examination of sheep tissues, circular to elongated, encapsulated, basophilic structures ranging from 30 to 3,000 µm in length and 20 to 1,000 µm in width were observed within the skeletal muscle fibers. In cattle tissues, all cardiac muscle four fragments analyzed contained circular to elongated basophilic structures inside cardiomyocytes and in some Purkinje fibers. PCR were performed using the primers: 2L and 3H. In conclusion, all 24 tissues were infected with Sarcocystis spp., and S. gigantea (in sheep) and S. cruzi (in cattle). were the identified species by sequencing.