Molecular Detection of Toxoplasma gondii Oocytes in the Soil from the Public Parks of the Arak City, Iran

Background and aim: soil structure is mainly composed of sand, silt, clay, andorganic materials. organisms can live in the soil. the large number of stray cats inthe cities of iran is a major environmental and health problem. toxoplasmaoocysts are shed with the feces of cats, so soil is known as a potential source oftransmission of toxoplasmosis. the aim of this study was to determine the soilcontamination with toxoplasma gondii oocyst in the public parks of the arak city.methods: sixty soil samples were collected from 15 main parks of arak city.four soil samples from the children's playground, a potting place, around trashbins, and around toilets were taken. oocyst was isolated from soil by floatation insaturated sucrose. floating debris was tested by two methods: staining by themodified ziehl-neelsen technique and pcr. the target of pcr was the 122 bpfragment of the b1 gene.results: from 60 soil samples of public parks of arak city, 8 samples (13%) weresuspected to toxoplasma oocyst contamination in staining smears. only 3 samples(5%) of 60 samples were positive in pcr. the results showed that the stainingmethod is not a good method to detect oocysts in the soil because the diversity ofoocyst in soil is very high and similar in appearance.conclusion: this study showed soils of public parks in the arak city werecontaminated to oocyst of toxoplasma. also molecular method for the detectionof parasites in the soil was more suitable than staining method.