Simplified technique for isolation, excystation, and culture of Sarcocystis species from opossums.

This research deals with a better technique for isolating, activating, and growing a particular species of a parasite (Sarcocystis) that’s typically found in opossums and could cause a neurological disease in horses.

Objective of the research

• The study aimed to create an efficient method for isolating, activating (excystation), and cultivating Sarcocystis species from opossums. The goal was to generate enough samples of the specific developmental stage of the parasite for comparative studies.

Background

• The research concerns the protozoan parasites Sarcocystis neurona that are responsible for a neurological condition in horses known as equine protozoal myeloencephalitis. These parasites are suspected to be transferred to the horses through feces from opossums.
• However, there is considerable debate about the natural life cycle of these parasites, and even about the correct identification of Sarcocystis species from opossums.

Methodology

• The researchers examined 27 opossums from southern Michigan for the presence of Sarcocystis species in the form of sporocysts (cysts containing spores).
• Among them, seven were positive for Sarcocystis sporocysts which were isolated via fecal flotation.
• Then, a simplified technique was developed for the isolation, activation, and culture of these parasites from the opossum’s mucosal scrapings.

Results

• The simplified method allowed the cultivating of Sarcocystis species successfully in equine dermal cells long-term until they developed into the merozoite stage (a stage in the life cycle of certain parasites).
• These merozoites became observable between 5 and 15 days following introduction into the culture fluids.

Conclusion

• In conclusion, the study affirmed that opossums do indeed shed Sarcocystis sporocysts that could be manipulated to grow in vitro in horse skin cell lines till they reach the merozoite stage. This was achieved using the simplified method proposed by the researchers.