Enteroepithelial stages of Toxoplasma gondii in the ileum of cats by serial block face scanning electron microscopy.

Abstract

This study investigates the enteroepithelial stages of Toxoplasma gondii in the feline ileum using high resolution field emission scanning electron microscopy (FE-SEM) and serial block face scanning electron microscopy (SBF-SEM). By employing advanced imaging techniques, including creative sample processing methods, this research provides new insights into the development, distribution, and maturation of T. gondii within infected intestinal cells. Comparison with previous studies confirms earlier findings while offering enhanced resolution and three-dimensional models of the parasite's progression. SBF-SEM enabled the visualization of asexual forms of the parasite, from merozoites to multinucleated schizonts and rosettes, distributed along the intestinal villi. These observations suggest a tendency for merozoites to accumulate near the villus extrusion zone, where they are later released. Despite these advancements, the mechanisms of gamete fertilization and oocyst egress remain unresolved, highlighting key areas for future research.