Figure 8 A serial study of blood films obtained from
infected deer and stained with Giemsa stain or immune conjugate
resulted in the differentiation of various developmental stages of
Babesia odocoilei. The nuclear and cytoplasmic elements of
the organisms were also differentiated. The schematically
illustrated life cycle for Babesia odocoilei (above) demonstrates
stage to stage development of the parasites as revealed by this
study. All forms except those of bud reproduction and the
unusual forms were seen regularly.
The smallest form observed in an erythrocyte was an anaplasmoid
body that consisted of nuclear material and no recognizable
cytoplasm (Figure 9). Enlargement of this body was associated
with an increase of cytoplasm and chromatin. Elongation of
the organism near the periphery of the erythrocyte preceded fission
in which 2 pypiform bodies were produced (Figures 8:1-8, 10,
11). Less frequently, fission produced maltese cross forms
within erythrocytes (Figure 8:11-13, 12). Maturation of a
maltese cross form produced 4 pyriform bodies which appeared as a
multiple infection of one erythrocyte. Bud reproduction
occurred infrequently. The parasite developed into a larger
round body with distinct chromatin and an increase in cytoplasm
(Figure 13). Two buds formed simultaneously, each developing
into a pyriform body which characterized the mature form of Babesia
odocoilei (Figure 8:14-18).
Lysis of infected erythrocytes released the pyriform organisms
into the plasma to possibly become attached to other erythrocytes
(Figure 15). Unusual forms and multiple infections of
erythrocytes occurred at the peak of the parasitemia.
Erythrocytes which contained mature and immature stages and
multiple adult forms were observed at this point (Figure
8:19-22,16).
