ABSTRACT
Background: Soil is an appropriate substrate for the storage and transmission of oocytes of Toxoplasma gondii. Ingestion of soil contaminated with T. gondii oocysts is a major transmission route of human and animal toxoplasmosis. The present study was carried out to investigate soil contamination with T. gondii oocysts in urban and rural areas of Guilan Province, northern Iran. Methods: Overall, 208 soil samples were collected from 16 cities and villages in Guilan Province, northern Iran from Oct 2020 to Nov 2021. Soil samples were investigated using modified sucrose flotation technique. Real-time polymerase chain reaction was used to detect presence of T. gondii DNAs in the samples. Positive samples were further analyzed using nested polymerase chain reaction for GRA6 gene. Moreover, six selected positive samples were used for amplifying and sequencing of the GRA6 gene. Results: Overall, 31 samples were positive for T. gondii with frequency of 14.9% and ranging from 10.9% in rural areas to 16.3% in urban areas. Statistical analysis showed significant differences between the seasons (P=0.003). The phylogenetic analysis illustrated that our six sequences were similar and closely related to Type I strain of T. gondii. Conclusion: Results showed relatively high levels (14.9%) of T. gondii oocytes in soil samples of Guilan Province, northern Iran, which provided essential data for the effective prevention and control of toxoplasmosis in the region.
ABSTRACT
Background: Toxoplasma infection is caused by Toxoplasma gondii, which is an intracellular protozoan parasite. This infection consequently lead various congenital disabilities during pregnancy in patients. Spiramycin (Spi), a macrolide antibiotic, is typically recommended for T. gondii infection in pregnant women. We aimed to prepare the nanoemulsion of spiramycin (NE-Spi) and to evaluate the activity of this formulation in tachyzoites of T. gondii, RH strain. Methods: This study was conducted in 2019-2021 at the School of Public Health, Tehran University of Medical Sciences, Tehran, Iran. NE-Spi was prepared by spontaneous emulsification. The effects of this nanoemulsion on the viability of cultured cells were measured using MTT assay. To estimate the effects of NE-Spi on tachyzoites of T. gondii, RH strain, different concentrations of NE-Spi, S-Spi (suspension of spiramycin), and NE (nanoemulsion without any spiramycin) were added to tachyzoites and then stored for 30, 60, 90, 120 min and 24 h in 250 µg/ml concentration at room temperature. Finally, Tachyzoites mortality rates were evaluated by trypan blue staining. Of note, flow cytometry was conducted to confirm the obtained results. Results: The final particle size of NE-Spi was calculated to be 11.3 nm by DLS and TEM. Thereafter, using MTT assay, in 62.5 µg/ml concentration of NE-Spi, the Vero cells viability was obtained as 82%. The highest mortality rates of tachyzoites of T.gondii, RH strain were observed at 250 µg/ml concentration and after 120 min of exposure, but it was not significantly different from 24 h of exposure. Conclusion: NE-Spi has lethal efficacy on T. gondii RH strain in-vitro.
