Skeletal muscle ultrastructural pathology in mice infected with Trypanosoma evansi.

An ultrastructural study of skeletal muscle alterations wascarried out in mice experimentally infected with Trypanosoma evansi. Manifested anomalies were found, in both muscle fibre and microvasculature. Muscle fibre changes included atrophy, autophagic vacuoles formation, mitochondrial degeneration, nuclei pyknosis and segmental necrosis. In another direction, the cytoplasm of capillary endothelial cells showed rough endoplasmic reticulum and mitochondrial swelling, as well as luminal infoldings; parasites were found in the endothelial cell cytoplasm. A mononuclear infiltrate, formed by macrophages and neutrophils, was also observed. This work shows that skeletal muscle is an important target tissue for Trypanosoma evansi.