Comparative Development of Eimeria tenella from Sporozoites to Oocysts in Primary Kidney Cell Cultures from Gallinaceous Birds

Eimeria tenella completed its endogenous life cycle in primary cultures of kidney cells from 2- to 3-week-old-chickens, guinea fowl, partridges, pheasants, quail, and turkeys. Similarity in percentage of infection at 4 hr suggested that sporozoites entered cells from all birds in equal numbers. Development was better, however, in chicken cells in that the percentage of survival and of developmental stages during the first 2 days were greater, developmental stages occurring after 2 days usually were found earlier, mature 2nd-generation schizonts and oocysts were larger, and oocyst production was far greater than in nonhost cells. Multinucleate macrogametes, which sometimes reached sizes 3–4 times greater than normal oocysts, are reported for the first time.