Eimeria tenella: cultivation of the asexual stages in cultured animal cells.

Eimeria tenella, an intracellular protozoan parasite of the cecal epithelium of chickens, developed asexually in monolayer cultures of mammalian fibroblasts, mammalian epithelial cells, and avian fibroblasts mintained under various mediums at 41 degrees C. Sexual stages of the parasite were not seen. Established cell lines and secondary cell cultures were equally suitable for cultivation of the parasite.