Adaptation of three babesia divergens isolates to continuous culture in rat erythrocytes

Three Babesia divergens isolates were cultured continuously for six months in rat erythrocytes using the candle jar technique. One isolate was already rat-adapted, the other two became adapted to rats through continuous culturing in the rat erythrocytes. Babesia was cultured in rat erythrocytes in RPMI medium supplemented with 20% fetal calf serum. The highest parasitemia was 35% and multi- parasitization of red blood cells was often observed. Cultures of B. divergens remained infective to splenectomized rats. Cultures with high parasitemias contained a large number of extracellular merozoites and when separated from the red blood cells, they retained their infectivity