Development of High Resolution Melting Analysis as a Diagnostic Tool for Molecular Detection of Toxoplasma Infection in Pregnant Women and HIV Positive Cases

Molecular Detection of Toxoplasma gondii Oocytes in Soil Samples from Guilan Province, Northern Iran

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.

The Therapeutic Efficacy of Zinc Oxide Nanoparticles on Acute Toxoplasmosis in BALB/c Mice

Background

Toxoplasma gondii infects nearly one-third of the world's population. Due to the significant side effects of current treatment options, identifying safe and effective therapies seems crucial. Nanoparticles (NPs) are new promising compounds in treating pathogenic organisms. Currently, no research has investigated the effects of zinc oxide NPs (ZnO-NPs) on Toxoplasma parasite. We aimed to investigate the therapeutic efficacy of ZnO-NPs against tachyzoite forms of T. gondii, RH strain in BALB/c mice.

Methods

In an experiment with 35 female BALB/c mice infected with T. gondii tachyzoites, colloidal ZnO-NPs at concentrations of 10, 20, and 50 ppm, as well as a 50 ppm ZnO solution and a control group, were orally administered four hours after inoculation and continued daily until the mices' death. Survival rates were calculated and tachyzoite counts were evaluated in the peritoneal fluids of infected mice.

Results

The administration of ZnO-NPs resulted in the reduction of tachyzoite counts in infected mice compared to both the ZnO-treated and control group (P<0.001). Intervention with ZnO-NPs significantly increased the survival time compared to the control group (6.2±0.28 days, P-value <0.05), additionally, the highest dose of ZnO-NPs (50 ppm) showed the highest mice survival time (8.7±0.42 days).

Conclusion

ZnO-NPs were effective in decreasing the number of tachyzoites and increasing mice survival time in vivo. Moreover, there were no significant differences in survival time between the untreated control group and the group treated with zinc oxide, suggesting that, bulk ZnO is not significantly effective in comparison with ZnONPs.

Toxoplasma gondii genotyping in AIDS patients using high resolution melt analysis (HRM analysis) in Khuzestan province, southwest Iran

Toxoplasmosis is a parasitic zoonotic disease caused by Toxoplasma gondii, a common protozoan in the Apicomplexa phylum. Several studies in Iran have demonstrated the presence of the parasite in various hosts, but no data on T. gondii genotyping in HIV patients in Khuzestan, Southwest Iran, is available. One hundred of blood samples from AIDS patients were collected and tested by real-time PCR High Resolution Melting analyses for T.gondii detection and genotyping. T. gondii was discovered in 8 out of 100 (8%) AIDS patients with dominant Type I. This study suggest that HRM method demonstrated excellent discriminating ability for T. gondii, and AIDS patients should be tested for Toxoplasma detection and genotyping to prevent parasite pathogenicity.