Trypanosoma vivax Adhesion to Red Blood Cells in Experimentally Infected Sheep.
Trypanosomosis, a globally occurring parasitic disease, poses as a major obstacle to livestock production in tropical and subtropical regions resulting in tangible economic losses. In Latin America including Venezuela, trypanosomosis of ruminants is mainly caused by Trypanosoma vivax. Biologically active substances produced from trypanosomes, as well as host-trypanosome cellular interactions, contribute to the pathogenesis of anemia in an infection. The aim of this study was to examine with a scanning electron microscope the cellular interactions and alterations in ovine red blood cells (RBC) experimentally infected with T. vivax. Ovine infection resulted in changes of RBC shape as well as the formation of surface holes or vesicles. A frequent observation was the adhesion to the ovine RBC by the trypanosome's free flagellum, cell body, or attached flagellum in a process mediated by the filopodia emission from the trypanosome surface. The observed RBC alterations are caused by mechanical and biochemical damage from host-parasite interactions occurring in the bloodstream. The altered erythrocytes are prone to mononuclear phagocytic removal contributing to the hematocrit decrease during infection.
Laboratorio de Microscopía Electrónica, Centro de Estudios Biomédicos y Veterinarios, Instituto de Estudios Científicos y Tecnológicos, Universidad Nacional Experimental Simón Rodríguez, Caracas, Venezuela.
Alpidio A
AA
Boada-Sucre
Unidad de Toxoplasmosis y Protozoosis, Departamento de Parasitología, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Calle Alejandro Casona 7, Piso 6D, 28035 Madrid, Spain; Sección de Inmunohistoquímica y Microscopía Electrónica, Instituto Anatomopatológico "José A. O'Daly", Facultad de Medicina, Universidad Central de Venezuela, Caracas, Venezuela.
Marcello Salvatore
MS
Rossi Spadafora
Grupo de Inmunobiología, Centro de Estudios Biomédicos y Veterinarios, Instituto de Estudios Científicos y Tecnológicos, Universidad Nacional Experimental Simón Rodríguez, Caracas, Venezuela.
Lucinda M
LM
Tavares-Marques
Centro de Microscopía Electrónica "Mitsuo Ogura", Facultad de Ciencias, Universidad Central de Venezuela, Caracas, Venezuela.
Héctor J
HJ
Finol
Grupo de Inmunobiología, Centro de Estudios Biomédicos y Veterinarios, Instituto de Estudios Científicos y Tecnológicos, Universidad Nacional Experimental Simón Rodríguez, Caracas, Venezuela; Investigador Prometeo, Universidad de Las Fuerzas Armadas ESPE, Departamento de Ciencias de la Vida, Grupo de Investigación de Sanidad Animal y Humana (GISAH), Sangolquí, Ecuador.
Armando
A
Reyna-Bello