Eimeria acervulina is a promising surrogate for Toxoplasma gondii oocysts exposed to chemical and physical treatments

Oocysts of the coccidian parasite Toxoplasma gondii withstand a wide range of chemical and physical factors, contributing to their food- and water-borne transmission to humans worldwide. Assessing the efficacy of processes to remove or inactivate oocysts at a pilot or industrial scale encounters major ethical, economic, and methodological constraints. The coccidian parasite Eimeria acervulina has been proposed as a non-human pathogenic alternative of T. gondii to assess food decontamination, however it is not known whether the two parasites exposed to chemical and thermal treatments parallel in terms of oocyst structure and infectivity. Using bioassays and lectin-based assays combined with flow cytometry and fluorescence microscopy analyses, this study shows that E. acervulina and T. gondii oocysts display similar response to heating and/or freezing and bleach or NaOH treatments, as in maintaining infectivity, with E. acervulina oocysts retaining their size and structure better than T. gondii. Collectively, our results suggest that E. acervulina is a reliable model for studying the response of T. gondii oocysts to certain chemical and physical agents. It could therefore serve as an affordable, non-pathogenic substitute for T. gondii when evaluating food decontamination processes, particularly in industrial settings.