Molecular Genotyping of Toxoplasma gondii in Sheep Aborted Fetuses Reveals Predominance of Type I Infection in Southwest of Iran

Background: We aimed to detect Toxoplasma gondii in ovine aborted fetuses and evaluate its genetic variations in the southwest of Iran. Methods: This cross-sectional study was performed on 100 aborted ovine fetuses collected from the different region of Kohgiluyeh and Boyer-Ahmad Province, Iran, in lambing season during 2017 and 2018. DNA was extracted from the brain samples of all of the aborted fetuses and PCR amplified, targeting a 529 bp repetitive element gene of T. gondii. Moreover, to find out the heterogeneity of the positive samples, PCR-DNA amplification of the two main genetic markers, B1 and GRA6, of T. gondii were performed. Nucleotide sequencing and phylogenetic analysis were performed, using the BLAST program and MEGA-X software. Results: The 529 bp gene of T. gondii was detected in 2 out of 100 (2%) of the ovine aborted samples. The sequences analysis of GRA6 and B1 genes revealed that both isolates from the aborted fetuses of sheep belonged to type I of T. gondii. Intra-divergence was more seen in GRA6 gene whereas less divergence was observed in B1 gene. Conclusion: Congenital infection with Type I of T. gondii during the neonatal period is associated with abortion in ovine. Evaluation of more aborted samples from broader geographical areas is needed to elucidate the molecular epidemiology and also the genotypes of T. gondii associated with abortion.