Skip to main content
NCBI home page
The Journal of Experimental Medicine logoLink to The Journal of Experimental Medicine
. 1970 Oct 1;132(4):636–662. doi: 10.1084/jem.132.4.636

THE TOXOPLASMA GONDII OOCYST FROM CAT FECES

J P Dubey 1, Nancy L Miller 1, J K Frenkel 1
PMCID: PMC2138867  PMID: 4927658

Abstract

Coccidian oocysts resembling those of Isospora bigemina were excreted by cats fed Toxoplasma. In order to identify these oocysts with Toxoplasma infectivity a number of critical comparisons were made. The appearance of oocysts and Toxoplasma infectivity was simultaneous in the feces of 23 of 24 adult cats, 3–5 days after feeding of Toxoplasma cysts; in the feces of 4 out of 9 cats, 7–10 days after feeding of trophozoites; and in 8 out of 17 cats, 20–24 days after feeding of cat feces containing oocysts. Oocysts and infectivity were present in similar numbers, and they disappeared simultaneously from the feces of cats. Oocysts and infectivity were also observed simultaneously in the feces of 9 kittens, 1–2 days old, fed Toxoplasma cysts. Oocysts could not be separated from infectivity by filtration, by continuous particle electrophoresis, or by density gradient centrifugation. Excystation of oocysts was followed by an increase in titer of Toxoplasma infectivity. Unsporulated oocysts in fresh cat feces were noninfectious to mice, but oocyst sporulation was associated quantitatively with the development of infectivity at different temperatures and conditions of oxygenation. Maximum oocyst sporulation at 48 hr correlated with the development of maximum Toxoplasma infectivity. 1 and 2% sulfuric acid, and 2.5% potassium dichromate were found to be the best preservatives for sporulation of oocysts and for the development of Toxoplasma infectivity. Low sporulation rates in 0.1% formalin, 20% ethanol, and in water were associated with low infectivity in these reagents. Neither Toxoplasma infectivity nor oocysts developed in 0.3% formalin, 1% ammonium hydroxide, or 1% iodine in 20% ethanol. Oocysts, sporocysts, and sporozoites were stained specifically with Toxoplasma antibody in the indirect fluorescent antibody test. Typical coccidian stages, schizonts, and male and female gametocytes were found in the epithelium of the small intestine of kittens fed Toxoplasma cysts. The classification of T. gondii is discussed in relation to that of other isosporan coccidia of cats and dogs. The term "Toxoplasma oocyst" is introduced and Toxoplasma is classified in the family Toxoplasmidae of the suborder Eimeriina. The species Isospora bigemina is restricted to dogs, and I. cati to cats. I. felis and so-called I. rivolta from cats were noninfectious to dogs, and did not confer immunity to subsequent infection with I. canis and I. rivolta from dogs.

Full Text

The Full Text of this article is available as a PDF (1.6 MB).

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Dubey J. P., Miller N. L., Frenkel J. K. Characterization of the new fecal form of Toxoplasma gondii. J Parasitol. 1970 Jun;56(3):447–456. [PubMed] [Google Scholar]
  2. Frenkel J. K., Dubey J. P., Miller N. L. Toxoplasma gondii in cats: fecal stages identified as coccidian oocysts. Science. 1970 Feb 6;167(3919):893–896. doi: 10.1126/science.167.3919.893. [DOI] [PubMed] [Google Scholar]
  3. Frenkel J. K., Dubey J. P., Miller N. L. Toxoplasma gondii: fecal forms separated from eggs of the nematode Toxocara cati. Science. 1969 Apr 25;164(3878):432–433. doi: 10.1126/science.164.3878.432. [DOI] [PubMed] [Google Scholar]
  4. Frenkel J. K., Good J. T., Shultz J. A. Latent Pneumocystis infection of rats, relapse, and chemotherapy. Lab Invest. 1966 Oct;15(10):1559–1577. [PubMed] [Google Scholar]
  5. GARNHAM P. C., BAKER J. R., BIRD R. G. Fine structure of cystic form of Toxoplasma gondii. Br Med J. 1962 Jan 13;1(5271):83–84. doi: 10.1136/bmj.1.5271.83. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. GARNHAM P. C., BIRD R. G., BAKER J. R., BRAY R. S. Electron microsope studies of motile stages of malaria parasites. II. The fine structure of the sporozoite of Laverania (Plasmodium) falcipara. Trans R Soc Trop Med Hyg. 1961 Jan;55:98–102. doi: 10.1016/0035-9203(61)90046-3. [DOI] [PubMed] [Google Scholar]
  7. HONIGBERG B. M., BALAMUTH W., BOVEE E. C., CORLISS J. O., GOJDICS M., HALL R. P., KUDO R. R., LEVINE N. D., LOEBLICH A. R., Jr, WEISER J. A REVISED CLASSIFICATION OF THE PHYLUM PROTOZOA. J Protozool. 1964 Feb;11:7–20. doi: 10.1111/j.1550-7408.1964.tb01715.x. [DOI] [PubMed] [Google Scholar]
  8. Hutchison W. M., Dunachie J. F., Siim J. C., Work K. Coccidian-like nature of Toxoplasma gondii. Br Med J. 1970 Jan 17;1(5689):142–144. doi: 10.1136/bmj.1.5689.142. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Hutchison W. M., Dunachie J. F., Siim J. C., Work K. Life cycle of toxoplasma gondii. Br Med J. 1969 Dec 27;4(5686):806–806. doi: 10.1136/bmj.4.5686.806-b. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Hutchison W. M. Experimental transmission of Toxoplasma gondii. Nature. 1965 May 29;206(987):961–962. doi: 10.1038/206961a0. [DOI] [PubMed] [Google Scholar]
  11. Hutchison W. M. The nematode transmission of Toxoplasma gondii. Trans R Soc Trop Med Hyg. 1967;61(1):80–89. doi: 10.1016/0035-9203(67)90056-9. [DOI] [PubMed] [Google Scholar]
  12. INNES J. R., ZEMAN W., FRENKEL J. K., BORNER G. Occult endemic encephalitozoonosis of the central nervous system of mice (Swiss-Bagg-O'Grady strain). J Neuropathol Exp Neurol. 1962 Oct;21:519–533. doi: 10.1097/00005072-196210000-00002. [DOI] [PubMed] [Google Scholar]
  13. JACOBS L., REMINGTON J. S., MELTON M. L. The resistance of the encysted form of Toxoplasma gondii. J Parasitol. 1960 Feb;46:11–21. [PubMed] [Google Scholar]
  14. Jervis H. R., Merrill T. G., Sprinz H. Coccidiosis in the guinea pig small intestine due to a Cryptosporidium. Am J Vet Res. 1966 Mar;27(117):408–414. [PubMed] [Google Scholar]
  15. Kühn D., Weiland G. Experimentelle Toxoplasma-Infektionen bei der Katze. I. Wiederholte Ubertragung von Toxoplasma gondii durch Kot von mit Nematoden infizierten Katzen. Berl Munch Tierarztl Wochenschr. 1969 Oct 15;82(20):401–404. [PubMed] [Google Scholar]
  16. Levine N. D., Ivens V. Isospora species in the dog. J Parasitol. 1965 Oct;51(5):859–864. [PubMed] [Google Scholar]
  17. Mahrt J. L. Endogenous stages of the life cycle of Isospora rivolta in the dog. J Protozool. 1967 Nov;14(4):754–759. doi: 10.1111/j.1550-7408.1967.tb02073.x. [DOI] [PubMed] [Google Scholar]
  18. Overdulve J. P. The identity of Toxoplasma Nicolle and Manceaux, 1909 with Isospora Schneider, 1881. I. Proc K Ned Akad Wet C. 1970;73(1):129–141. [PubMed] [Google Scholar]
  19. Sabin A. B., Feldman H. A. Dyes as Microchemical Indicators of a New Immunity Phenomenon Affecting a Protozoon Parasite (Toxoplasma). Science. 1948 Dec 10;108(2815):660–663. doi: 10.1126/science.108.2815.660. [DOI] [PubMed] [Google Scholar]
  20. Scholtyseck E., Piekarski G. Elektronenmikroskopische Untersuchungen an Merozoiten von Eimerien (Eimeria perforans und E. stiedae) und Toxoplasma gondii. Zur systematischen Stellung von T. gondii. Z Parasitenkd. 1965 Oct 18;26(2):91–115. doi: 10.1007/BF00348725. [DOI] [PubMed] [Google Scholar]
  21. Sheffield H. G., Melton M. L. The fine structure and reproduction of Toxoplasma gondii. J Parasitol. 1968 Apr;54(2):209–226. [PubMed] [Google Scholar]
  22. Sheffield H. G., Melton M. L. Toxoplasma gondii: the oocyst, sporozoite, and infection of cultured cells. Science. 1970 Feb 6;167(3919):892–893. doi: 10.1126/science.167.3919.892. [DOI] [PubMed] [Google Scholar]
  23. Vetterling J. M. Continuous-flow differential density flotation of coccidial oocysts and a comparison with other methods. J Parasitol. 1969 Apr;55(2):412–417. [PubMed] [Google Scholar]
  24. Work K., Hutchison W. M. A new cystic form of Toxoplasma gondii. Acta Pathol Microbiol Scand. 1969;75(1):191–192. [PubMed] [Google Scholar]
  25. Work K., Hutchison W. M. The new cyst of Toxoplasma gondii. Acta Pathol Microbiol Scand. 1969;77(3):414–424. doi: 10.1111/j.1699-0463.1969.tb04248.x. [DOI] [PubMed] [Google Scholar]

Articles from The Journal of Experimental Medicine are provided here courtesy of The Rockefeller University Press

RESOURCES