Effect of Whole-Cell Lysates on Invasion Rate of Eimeria Sporozoites In Vitro

One of the diseases causing the greatest economic damage to the poultry industry is coccidiosis. Effective in vitro screening platforms can accelerate research on coccidiosis control by identifying and prioritizing interventions for subsequent validation in more resource- and labor-intensive in vivo studies. Consequently, increasing the invasion rate of Eimeria sporozoites is considered a crucial step in elucidating the process of parasitic infection and defense mechanisms. This study investigated the invasion rate of E. tenella sporozoites upon the supplementation of whole-cell lysates and quantified the sporozoite load using microscopic counting and an absolute quantitative real-time PCR assay targeting the internal transcribed spacer 1 (ITS-1) region of the nuclear ribosomal DNA of E. tenella. Compared to cell culture media with invasion rates of 13.9–34.4%, the whole-cell lysate supplementation significantly enhanced sporozoite invasion to 38.7–81.3% over time (p < 0.05). These findings enable the efficient use of the large quantities of sporozoites required for repeated experiments and also reduce the need for the difficult and time-consuming process of extracting sporozoites from sporulated oocysts. This result is expected to be highly beneficial for cell-based experiments utilizing Eimeria sporozoites.