Skip to main content Accessibility help

In vitro isolation and characterization of a Neospora sp. from aborted bovine foetuses

  • P. A. Conrad (a1), B. C. Barr (a2), K. W. Sverlow (a2), M. Anderson (a2), B. Daft (a2), H. Kinde (a2), J. P. Dubey (a3), L. Munson (a4) and A. Ardans (a2)...


A Neospora sp. was isolated from the brains of two aborted bovine foetuses and grown continuously in vitro in bovine cell cultures. A comparison of the antigenic reactivity of in vitro cultivated tachyzoites with polyclonal antisera to Neospora caninum, Hammondia hammondi or Toxoplasma gondii revealed that the bovine protozoal isolates were similar to N. caninum and antigenically distinct from T. gondii. Tachyzoites of both bovine isolates had similar ultrastructural features, including an apical polar ring, conoid, electron-dense rhoptries and micronemes. The orientation of the micronemes, presence of micropores and a large number of electron-dense granules in the posterior portion of the bovine isolate tachyzoites differed from previous descriptions of N. caninum in vivo. Tachyzoites of the bovine isolates were ultrastructurally more similar to in vitro cultivated N. caninum tachyzoites than to tachyzoites of T. gondii or H. hammondi. The antigenic and ultrastructural similarities between N. caninum and the protozoal parasites isolated from aborted bovine foetuses in this study support the proposition that these parasites belong to the genus Neospora.



Hide All
Anderson, M. L., Blanchard, P. C., Barr, B. C., Dubey, J. P., Hoffman, R. L. & Conrad, P. A. (1991). Neospora- like protozoal infection as a major cause of abortion in California dairy cattle. Journal of the American Veterinary Medical Association 198, 241–4.
Barr, B. C., Anderson, M. L., Blanchard, P. C., Daft, B. M., Kinde, H. & Conrad, P. A. (1990). Bovine fetal encephalitis and myocarditis associated with protozoal infections: A two year retrospective study of cases in California. Veterinary Pathology 27, 354–61.
Barr, B. C., Anderson, M. L., Dubey, J. P. & Conrad, P. A. (1991 a). Neospora-like protozoal infections associated with bovine abortions. Veterinary Pathology 28, 110–16.
Barr, B. C., Conrad, P. A., Dubey, J. P. & Anderson, M. L. (1991 b). Neospora-like encephalitis in a calf: pathology, ultrastructure, and immunoreactivity. Journal of Veterinary Diagnostic Investigation 3, 3946.
Bjerkas, I. & Dubey, J. P. (1991). Evidence that Neospora caninum is identical to the Toxoplasma-like parasite of Norwegian dogs. Acta Veterinaria Scandinavia 32, 407–10.
Bjerkas, I. & Landsverk, T. (1986). Identification of Toxoplasma gondii and Encephalitozoon cuniculi by immunoperoxidase techniques and electron microscopy, in stored, formalin-fixed, paraffin- embedded tissue. Acta Veterinaria Scandinavia 27, 1122.
Bjerkas, I., Mohn, S. F. & Presthus, J. (1984). Unidentified cyst-forming sporozoon causing encephalomyelitis and myositis in dogs. Zeitschrift für Parasitenkunde 70, 271–4.
Bjerkas, I. & Presthus, J. (1988). Immuno-histochemical and ultrastructural characteristics of a cyst-forming sporozoon associated with encephalomyelitis in dogs. Acta Pathologica, Microbiologica et Immunologica Scandinavica 96, 445–54.
Bjerkas, I. & Presthus, J. (1989). The neuropathology in toxoplasmosis-like infection caused by a newly recognized cyst-forming sporozoon in dogs. Acta Pathologica, Microbiologica et Immunologica Scandinavica 97, 459–68.
Burg, J. L., Perlman, D., Kasper, L. H., Ware, P. L. & Boothroyd, J. C. (1988). Molecular analysis of the gene encoding the major surface antigens of Toxoplasma gondi. Journal of Immunology 141, 3584–91.
Cummings, J. F., De Lahunta, A., Suter, M. M. & Jacobson, R. H. (1988). Canine protozoan polyradiculoneuritis. Acta Neuropathologica 76, 4654.
Dubey, J. P. (1986). A review of toxoplasmosis in cattle. Veterinary Parasitology 22, 177202.
Dubey, J. P. (1989). Congenital neosporosis in a calf. Veterinary Record 125, 486.
Dubey, J. P. & Beattie, C. P. (1988). Toxoplasmosis of Animals and Man, Boca Ratan, Florida: CRC Press.
Dubey, J. P., Carpenter, J. L., Speer, C. A., Topperrk, M. J. & Uggla, A. (1988 a). Newly recognized fatal protozoan disease of dogs. Journal of the American Veterinary Medical Association 192, 1269–85.
Dubey, J. P., Hartley, W. J. & Lindsay, D. S. (1990a a). Congenital Neospora caninum infection in a calf with spinal cord anomaly. Journal of the American Veterinary Medical Association 197, 1043–4.
Dubey, J. P., Hattel, A. L., Lindsey, D. S. & Topper, M. J. (1988 b). Neonatal Neospora caninum infection in dogs: Isolation of the causative agent and experimental transmission. Journal of the American Veterinary Medical Association 193, 1259–63.
Dubey, J. P., Leathers, C. W. & Lindsey, D. S. (1989). Neospora caninum-like protozoan associated with fatal myelitis in newborn calves. Journal of Parasitology 75, 146–8.
Dubey, J. P., Miller, S., Lindsay, D. S. & Topper, M. J. (1990 b). Neospora caninum-associated myocarditis and encephalitis in an aborted calf. Journal of Veterinary Diagnostic Investigation 2, 66–9.
Garnham, P. C. C., Baker, J. R. & Bird, R. G. (1962). Fine structure of cystic form of Toxoplasma gondii. British Medical Journal 13, 83–4.
Goldman, M., Carver, R. K. & Sulzer, A. J. (1958). Reproduction of Toxoplasma gondii by internal budding. Journal of Parasitology 44, 161–71.
Hartley, W. J. & Bridge, P. S. (1975). A case of suspected congenital Toxoplasma encephalomyelitis in a lamb associated with a spinal cord anomaly. British Veterinary Journal 131, 380–3.
Hartley, W. J. & Kater, J. C. (1963). The pathology of Toxoplasma infection in the pregnant ewe. Research in Veterinary Science 4, 326–32.
Lindsay, D. S. & Dubey, J. P. (1989 a). In vitro development of Neospora caninum (Protozoa: Apicomplexa) from dogs. Journal of Parasitology 75, 163–5.
Lindsay, D. S. & Dubey, J. P. (1989 b). Immunohistochemical diagnosis of Neospora caninum in tissue sections. American Journal of Veterinary Research 50, 1981–3.
Lindsay, D. S., Speer, C. A., Toivio-Kinnucan, M., Dubey, J. P. & Blagburn, B. L. (1993). Comparative ultrastructure of Neospora caninum from dogs and Toxoplasma gondii in cultured cells. American Journal of Veterinary Research (in the Press).
Munson, L., Chandler, S. K. & Schlafer, D. H. (1988). Long-term culture of bovine trophoblastic cells. Journal of Tissue Culture Methods 11, 123–8.
Nietfeld, J. C., Dubey, J. P., Anderson, M. L., Libal, M. C., Yaeger, M. J. & Neiger, R. D. (1992). Neospora-like protozoan infection as a cause of abortion in dairy cattle. Journal of Veterinary Diagnostic Investigation 4, 223–6.
Obendorf, D. & Mason, R. (1990). Neospora caninum infection detected in a bovine aborted foetus. Australian Society of Veterinary Pathology Report 28, 36–7.
Ogino, N. & Yoneda, C. (1966). The fine structure and mode of division of Toxoplasma gondii. Archives of Ophthalmology 75, 218–27.
O'Toole, D. & Jeffrey, M. (1987). Congenital sporozoan encephalomyelitis in a calf. Veterinary Record 121, 563–6.
Parish, S. M., Maag-Miller, L., Besser, T. E., Weidner, J. P., McElwain, T., Knowles, D. P. & Leathers, C. W. (1987). Myelitis associated with protozoal infection in newborn calves. Journal of the American Veterinary Medical Association 191, 1599–600.
Scholtyseck, E. (1979). Fine Structure of Parasitic Protozoa. An Atlas of Micrographs, Drawings and Diagrams. New York: Springer.
Scholtyseck, E., Mehlhorn, H. & Muller, B. E. G. (1973). Identification von Merozoiten der vier cystenbildenden Coccidien (Sarcocystís, Toxoplasma, Besnoitia, Frenkelia) auf Grund feinstruktureller Kriterien. Zeitschrift für Parasitenkunde 42, 185206.
Sheffield, H. G. & Melton, M. L. (1968). The fine structure and reproduction of Toxoplasma gondii. Journal of Parasitology 54, 209–26.
Sheffield, H. G., Melton, M. L. & Neva, F. A. (1976). Development of Hammondia hammondi in cell cultures. Proceedings of the Helminthological Society of Washington 43, 217–25.
Shivaprasad, H. L., Ely, R. & Dubey, J. P. (1989). A Neospora-like protozoan found in an aborted bovine placenta. Veterinary Parasitology 34, 145.
Speer, C. A. & Dubey, J. P. (1989). Ultrastructure of tachyzoites, bradyzoites and tissue cysts of Neospora caninum. Journal of Protozoology 36, 458–63.
Speer, C A., Dubey, J. P., Blixt, J. A. & Blagburn, B. (1988). Development of Hammondia heydorni in cultured bovine and ovine cells. Journal of Protozoology 35, 352–6.
Speer, C A., Reduver, D. W., Burgess, D. E., Whitmire, W. M. & Splitter, G. A. (1985). Lymphokine-induced inhibition of growth of Eimeria bovis and E. pipillata (Apicomplexa) in cultured monocytes. Infection and Immunity 50, 566–71.
Thilsted, J. P. & Dubey, J. (1989). Neosporosis-like abortions in a herd of dairy cattle. Journal of Veterinary Diagnostic Investigation 1, 205–9.
Thornton, R. A., Thompson, E. J. & Dubey, J. P. (1991). Neospora protozoal abortion in New Zealand cattle. New Zealand Veterinary Journal 39, 129–33.
Wouda, W., Visser, I. J. R. & van Knapen, F. (1992). Bovine protozoal abortion. Veterinary Record 130, 279.



Altmetric attention score

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed