ULTRASTRUCTURAL CHARACTERISTICS OF BABESIA-ODOCOILEI INVITRO

Babesia odocoilei continuously cultured in white-tailed deer (Odocoile us virginianus) erythrocytes was examined by transmission and scanning electron microscopy. Merozoites. trophozoites, intermediate-stage for ms. and dividing forms were observed. Merozoites possessed a single nu cleus, inner membrane complex, rhoptries, free ribosomes, rough endopl asmic reticulum. and single membrane-bound vesicles. Trophozoites lack ed an inner membrane complex and rhoptries. Intermediate stages were c haracterized by distinct segments of inner membrane complex. Dividing forms ranged from cells with an elongated nucleus to mature daughter c ells joined by a ringlike structure. Babesia odocoilei was characteriz ed by its close proximity to the erythrocyte membrane. membranous stru ctures resembling feeding organelles, and reproduction via a method re sembling budding sensu stricto.