Cystoisospora suis merozoite development assay for screening of drug efficacy in vitro

Progression of asexual to sexual stages of Cystoisospora suis in a host cell-free environment as a model for Coccidia

“…The current study describes a novel host cell-free culture system for C. suis as a representative of the intestinal Coccidia and compares the parasite's morphological development with the transcription profile of selected sexual genes previously identified. A C. suis in vitro model employing intestinal host cell monolayer cultures is already established and is suitable for several applications (Worliczek et al ., 2013 ; Feix et al ., 2020 ; Joachim and Ruttkowski, 2021 ). We hypothesized that (i) after the intracellular propagation of merozoites, C. suis can complete its life cycle in a host cell-free environment which can be demonstrated by the development of gamonts, gametes, unsporulated and sporulated oocysts; and that (ii) the expression of genes related to the sexual development of C. suis is comparable to the in vitro expression in cell cultures infected with C. suis .…”

Pharmacokinetics of ponazuril after administration of a single oral dose to green turtles (Chelonia mydas)

“…To our knowledge, plasma ponazuril concentrations necessary to inhibit Caryospora cheloniae or other reptile protozoan parasites have not been reported to date. However, in vitro inhibition of ponazuril against other apicomplexan parasites has been reported, such as the reported ponazuril IC 50 of the coccidian parasite Cystoisospora suis of 3.4 µg/ml (Joachim and Ruttkowski 2021 ). Several studies have also described inhibition of Sarcocystis neurona using in vitro systems, though a limited range in ponazuril concentrations have been tested (Lindsay et al 2000 ; Mitchell et al 2005 ).…”