Isolation and establishment in in vitro culture of a Theileria annulata--infected cell line from Spain.

The isolation of Theileria annulata-infected lymphocytes using blood from an animal suffering from Mediterranean theileriosis as a source of parasites is described. The present work reports the first isolation and establishment in in vitro culture of a T. annulata-infected cell line from southwestern Europe, where Mediterranean theileriosis causes important economic losses, especially in southern Spain. The parasite was identified by staining of cells from culture with Giemsa, by immunofluorescent antibody techniques (IFAT), and by isoenzyme characterization. The possibility of using this T. annulata-infected lymphoblastoid cell line to obtain an antigen for diagnosis of Mediterranean theileriosis by IFAT and to develop a tissue-culture vaccine against this disease in our geographic area shows the significance of this isolation and culture.