Introduction: Sheep farming is one of the most important economic aspects of the livestock industry in Gilan province, Iran. Toxoplasmosis is a prevalent zoonotic disease and a major cause of abortion, congenital infection, and stillbirth in animals and humans. Previously, it was assumed that sheep are mostly infected with Toxoplasma gondii (T. gondii) after birth. Nevertheless, recent studies have shown that T. gondii congenital transmission is more prevalent than previously speculated. Therefore, determining the genotypes of this parasite in the intermediate host plays an important role in human infections and prevention programs. This cross-sectional study aimed to determine the T. gondii genetic diversity in aborted ovine fetuses during the lambing season (2018-2019) in Gilan province, Iran.
Materials and Methods: Molecular detection of T. gondii was performed in 44 brain tissue samples, collected from aborted ovine fetuses, using a nested polymerase chain reaction (nested-PCR) assay, to target the GRA6 gene. Also, the nested-PCR products belonging to the GRA6-positive samples underwent genotyping with the help of Tru1I (MseI) restriction enzyme using the PCR-restriction fragment length polymorphism (PCR-RFLP) method to classify strains into one of the three major lineages of T. gondii.
Results: The results revealed infection in 30 (68.18%) out of 44 brain samples of aborted ovine fetuses, based on the nested-PCR assay with GRA6 gene. Also, the PCR-RFLP results demonstrated the predominance of type II T. gondii in all of the isolates.
Conclusion: Overall, the present results revealed the high incidence of T. gondii infection through congenital transmission.This is the first molecular detection and genotyping of T. gondii in ovine aborted fetuses in Gilan Province, Iran.