Investigation of endothelial cells as an in vivo nidus of Anaplasma marginale infection in cattle

► Anaplasma marginale infects cattle for years by parasitizing red blood cells. ► Red blood cells only circulate for about four months and then are phagocytized. ► Prior in vitro work suggested that endothelial cells might also be infected. ► In vivo endothelial cell infection was investigated by multiple techniques. ► No conclusive proof of A. marginale endothelial cell infection in vivo was found.