Equine Sarcocystosis in the Northern Region of the Republic of Kazakhstan.

Simple Summary: Horse meat consumption in Kazakhstan is a long-standing tradition, dating back to the steppe nomads' era. It has been a staple in the country's culinary heritage for centuries. The issue of the safety and nutritional value of horse meat remains a significant concern. Our research has revealed the presence of sarcocystosis in horse meat in northern Kazakhstan. Sarcocystosis affects the muscle tissue, thereby reducing the meat nutritional value. The conducted analyses results demonstrated the consequences that parasites have on the muscles of affected animals, which inevitably affect the meat quality. Molecular genetic analyses have identified two species of the aforementioned parasite. It is important to note that sarcocystosis is a dangerous disease for humans. In immunodeficient individuals, it can lead to the development of various pathological processes and, in some cases, to a lethal outcome. The findings of our investigation elucidated the prevalence of sarcocystosis in horses. The data obtained will facilitate the formulation of a plan for the implementation of preventive measures to combat sarcocystosis and the dissemination of information among veterinary professionals employed on farms. This will undoubtedly contribute to the enhancement of safety and quality control measures for meat derived from domestic animals, while simultaneously preventing human infection. Background: A total of 396 samples were taken from the hearts, oesophagi, and diaphragms of 132 horses slaughtered at slaughterhouses in 2023 for subsequent examination. Methods: The histological method revealed pathomorphological changes in the muscle tissue. The molecular method identified the pathogen species. Results: Histological examination revealed thick-walled cysts with internal septa and numerous bradyzoites, and mononuclear inflammatory cells with pericyst infiltrates. Microcyst samples were amplified by polymerase chain reaction. Molecular genetic analysis allowed for the identification of 18 sarcocysts. Phylogenetic analysis of Sarcocystis isolates revealed three separate clades of Sarcocystis bertrami and two separate clades of Sarcocystis fayeri. Comparison and phylogenetic analysis revealed a very close relationship between the identified Sarcocystis species and other equine Sarcocystis DNA sequences from China and Japan. Based on the results obtained, the epizootic situation and the parasitic level of sarcocystosis contamination of horses in the northern Kazakhstan were determined. Conclusion: This is the first histological and molecular study to identify Sarcocystis spp. isolated from microscopic forms of equine sarcocysts in the northern Kazakhstan. This research will contribute to the fight against the spread of sarcocystosis in the Republic of Kazakhstan and will allow us to develop proposals for improving the mechanisms of sarcocystosis control. [ABSTRACT FROM AUTHOR]