Phylogenetic study of protozoan Toxoplasma gondii using Cytochrome b and Gra۲۰ genes

Toxoplasma gondii is an obligate intracellular protozoan in the phylum Apicomplexa. In addition to humans, toxoplasmosis can also cause serious diseases in livestock, leading to significant economic losses. The Toxoplasma gondii parasite is transmitted through the feces of its primary host, the Felidae family. The use of molecular methods with high sensitivity has made it possible to detect and study microorganisms. In this study the cytochrome b and dense granule ۲۰ (Gra۲۰) genes were utilized for studying Toxoplasma gondii parasites. After collecting ۲۹ animal samples of Toxoplasma gondii, the PCR method was applied to evaluate the presence of Gra۲۰ and cytochrome b genes. The sequence of ۱۱ samples was acceptable and submitted in the NCBI database. Mega X software was utilized to create the phylogenetic tree. In addition, the genetic diversity was studied using the RFLP-PCR assay for Gra۶ gene.Assessment of the bands obtained from PCR showed that the bands related to cytochrome b are found in all species of the Sarcocystidae family, but the bands related to the Gra۲۰ gene are specific to Toxoplasma gondii. In the phylogenic tree, there was a closer relationship between Iranian isolates of Toxoplasma gondii and French strain of Toxoplasma gondii. Type I was determined as the genetic type of protozoan Toxoplasma gondii isolated from Iran.Based on the results, the cytochrome b gene was considered as a general gene for recognizing different species of the Sarcocystidae family, however divergence was seen in the Gra۲۰ gene, which is considered a particular gene for Toxoplasma gondii.

Keywords:

Toxoplasma gondii , dense granule ۲۰ (GRA۲۰) , Cytochrome b , Phylogenetic analysis