Frequency of Toxoplasma gondii in Livestock Meats Using Nested PCR and RFLP in Sabzevar City, Iran

Abstract

Background: We investigated the prevalence of Toxoplasma gondii in slaughtered livestock (sheep, goats, camels) in Sabzevar, Eastern Iran using nested PCR methods.

Methods: Samples of diaphragm and heart tissue were collected from 40 sheep, 40 goats, and 40 camels at local slaughterhouses. DNA was extracted from the samples and analyzed using nested PCR targeting the B1 gene of T. gondii.

Results: The results indicate an overall prevalence of 60% (24/40) in sheep, with 37.5% (15/40) of diaphragm samples and 22.5% (9/40) of heart samples testing positive. In goats, the overall prevalence was 52.5% (21/40), with 35% (14/40) of diaphragm and 17.5% (7/40) of heart samples positive. Camels showed the highest prevalence at 65% (26/40), with 45% (18/40) of diaphragm and 20% (8/40) of heart samples infected. Diaphragm tissue showed higher infection rates compared to the heart in all species. No significant difference was found in infection rates between male and female animals. RFLP analysis using XhoI on selected positive PCR products differentiated genotypes based on digestion patterns. Among analyzed samples (19 per species), genotypes II/III were identified in 57.9% (11/19) of sheep, 36.8% (7/19) of goats, and 47.4% (9/19) of camels, with the remainder likely genotype I or undigested II/III.

Conclusion: The high prevalence rates observed, especially in diaphragm tissue and in camels, have important implications for public health and food safety. Enhanced meat inspection, public education, and further research on effective control measures are recommended.