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Endogenous stages of a ‘chick embryo-adapted’ strain of Eimeria tenella

Published online by Cambridge University Press:  06 April 2009

P. L. Long
P. L. Long
Affiliation:
Houghton Poultry Research Station, Houghton, Huntingdon
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Extract

A strain of E. tenella which had been passaged serially in 42 batches of chick embryos appeared to have lost its ability to produce the characteristically large second-generation schizonts in both the embryonic chorioallantois and in the chicken caeca. Numerous small schizonts (10–16 µm in diameter), which contained 8–30 small merozoites, replaced the large second-generation schizonts characteristic of this species. The small schizonts were numerous 3–5 days after inoculation and were restricted to epithelial cells of the embryo allantois when sporozoites were inoculated via the allantoic cavity. These schizonts also occurred in epithelial cells of the caeca of chickens given oocysts via the crop. Cell reactions in the chicken caeca in response to infection were minimal. Numerous minute lesions were present in the chorioallantois 4–6 days after inoculation; these were associated with the small schizonts and later with gamonts and oocysts. The strain reproduced well in the embryo but failed to induce gross pathogenic effects and no mortality resulted from the infection.

Only two passages of this strain in chickens were needed to restore a high degree of pathogenicity. This change was accompanied by the reappearance of the characteristically large second-generation schizonts in the tunica propria of the caecal wall.

Type
Research Article
Information
Parasitology , Volume 66 , Issue 1 , February 1973 , pp. 55 - 62
Copyright
Copyright © Cambridge University Press 1973

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References

Becker, E. R., (1934). Coccidia and coccidiosis of domesticated, game and laboratory animals and of man. The Iowa State College Press, Ames, Iowa.CrossRefGoogle Scholar
Doran, D. J., (1970). Eimeria tenella: from sporozoites to oocysts in cell culture. Proceedings of the Helminthological Society of Washington 70, 84–92.Google Scholar
Joyner, L. P., & Norton, C. C., (1969). A comparison of two laboratory strains of Eimeria tenella. Parasitology 59, 907–913.CrossRefGoogle ScholarPubMed
Long, P. L., (1965). Development of Eimeria tenella in avian embryos. Nature, London. 208, 509–10.Google Scholar
Long, P. L., (1969). Observations on the growth of Eimeria tenella in cultured cells from the parasitized chorioallantoic membranes of the developing chick embryo. Parasitology 59, 757–65.CrossRefGoogle ScholarPubMed
Long, P. L., (1970 a). Some factors affecting the severity of infection with Eimeria tenella in chicken embryos. Parasitology 60, 435–47.CrossRefGoogle ScholarPubMed
Long, P. L., (1970 b). Eimeria tenella: chemotherapeutic studies in chick embryos with a description of a new method (chorioallantoic membrane foci counts) for evaluating infections. Zeitscrift für Parasitenkunde 33, 329–38.CrossRefGoogle ScholarPubMed
Long, P. L., (1971). Maintenance of intestinal protozoa in vivo with particular reference to Eimeria and Histomonas. In Isolation and Maintenance of Parasites in vivo. 9th Symposium of the British Society for Parasitology, pp. 65–75. Ed. Taylor, A. E. R. and Muller, R.. Oxford: Blackwells.Google Scholar
Long, P. L., (1972). Eimeria tenella in chick embryos: reproduction, pathogenicity and immunogenicity of a strain maintained in embryos by serial passage. Journal of Comparative Pathology and Therapeutics. (In the Press.)Google ScholarPubMed
Strout, R. G., & Ouellette, C. A., (1969). Gametogony of Eimeria tenella (Coccidia) in cell cultures. Science 163, 695–6.CrossRefGoogle ScholarPubMed