THE ADAPTATION OF 3 ISOLATES OF BABESIA-DIVERGENS TO CONTINUOUS CULTURE IN RAT ERYTHROCYTES

Three isolates of Babesia divergens have been cultured continuously for 6 months in rat erythrocytes using the candle jar technique (Trager & Jensen, 1976). One isolate was already rat-adapted, the other two became adapted to rats through continuous culture in rat erythrocytes. Parasites were cultured in rat erythrocytes in RPMI medium supplemented with 20 % foetal calf serum. The highest parasitaemia obtained was 35 % and multiparasitization of red blood cells was often observed. Cultures of B. divergens remained infective to splenectomized rats. Cultures with high parasitaemias contained a large number of extracellular merozoites. When separated from the red blood cells, these extracellular merozoites retained their infectivity.