Use of infected cultured cells to compare ultrastructural features of Neospora caninum from dogs and Toxoplasma gondii

Am J Vet Res. 1993 Jan;54(1):103-6.


The ultrastructure of tachyzoites of 3 isolates of Neospora caninum from dogs was examined, using transmission electron microscopy of infected cultured cells. Ultrastructure of the 3 isolates was similar. Tachyzoites had a pellicle, 22 subpellicular microtubules, a conoid, anterior and posterior polar rings, 8 to 12 electron-dense rhoptries, numerous micronemes, a single vesicular nucleus, tubular mitochondria, Golgi complexes, ribosomes, endoplasmic reticula, an inactive micropore, electron-dense bodies, lipid bodies, and amylopectin bodies. Most tachyzoites were located adjacent to the host cell nucleus in a parasitophorous vacuole that contained numerous intravacuolar tubules. Tachyzoites divided by endodyogeny. Neospora caninum tissue cysts were not seen. Comparison of N caninum with Toxoplasma gondii tachyzoites indicated that the 2 species can be differentiated on the basis of structure and numbers fo rhoptries and numbers and location of micronemes and electron-dense bodies.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apicomplexa / ultrastructure*
  • Cattle
  • Cells, Cultured
  • Dogs / parasitology*
  • Humans
  • Toxoplasma / ultrastructure*