Acta Parasitologica

, Volume 64, Issue 2, pp 384–389 | Cite as

Evaluation of RE and B1 Genes as Targets for Detection of Toxoplasma gondii by Nested PCR in Blood Samples of Patients with Ocular Toxoplasmosis

  • Bahman Rahimi Esboei
  • Bahram Kazemi
  • Mohammad Zarei
  • Mehdi Mohebali
  • Hossein Keshavarz ValianEmail author
  • Saeedeh Shojaee
  • Fatemeh Zahedipour
  • Shirzad Fallahi
  • Parisa Mousavi
  • Raziyeh Mahmoudzadeh
  • Mirataollah Salabati
Original Paper



To evaluate B1 and RE genes as targets to detect Toxoplasma gondii, nested PCR is used in blood samples of patients with ocular toxoplasmosis.

Materials and Methods

Following the measurement of IgG and IgM antibodies using indirect ELISA, IgG avidity and assessment of blood samples by nested PCR, the agreement between various test results was studied.


From 117 patients, 77 (65.81%) were found to be positive for IgG anti-Toxoplasma antibody, 12 cases were positive for both IgG and IgM, and 1 patient was positive for IgM only. The detection limit for the RE-nested PCR assay was one T. gondii tachyzoite, whereas the limit for B1-nested PCR was five tachyzoites. Nested PCR results showed higher agreement with IgM test results than IgG test results.


The results of this study showed that nested PCR of peripheral blood is a useful and non-invasive method for detection of T. gondii in patients with OT, especially in case of recently acquired infections, and RE targeted assay is more sensitive than B1 targeted assay for this purpose.


Toxoplasma gondii Ocular toxoplasmosis Nested PCR RE gene B1 gene 



The authors would like to express their gratitude to all lab staff of Cellular and Molecular Biology Research Center of Shahid Beheshti University of Medical Sciences for their contribution in the study and toxoplasmosis laboratory in Tehran University of Medical Sciences for preparation of the T. gondii (RH strain) tachyzoites.


This project is supported by Tehran University of Medical Science (Grant No: 29998-160-03-94).

Compliance with Ethical Standards

Conflict of Interest

The authors declare that they have no conflict of interest.


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Copyright information

© Witold Stefański Institute of Parasitology, Polish Academy of Sciences 2019

Authors and Affiliations

  • Bahman Rahimi Esboei
    • 1
  • Bahram Kazemi
    • 2
  • Mohammad Zarei
    • 3
  • Mehdi Mohebali
    • 1
  • Hossein Keshavarz Valian
    • 1
    Email author
  • Saeedeh Shojaee
    • 1
  • Fatemeh Zahedipour
    • 2
  • Shirzad Fallahi
    • 4
  • Parisa Mousavi
    • 1
  • Raziyeh Mahmoudzadeh
    • 3
  • Mirataollah Salabati
    • 3
  1. 1.Department of Medical Parasitology and Mycology, School of Public HealthTehran University of Medical SciencesTehranIran
  2. 2.Cellular and Molecular Biology Research CenterShahid Beheshti University of Medical SciencesTehranIran
  3. 3.Eye Research Center, Farabi Eye HospitalTehran University of Medical SciencesTehranIran
  4. 4.Department of Medical Parasitology and MycologyLorestan University of Medical SciencesKhorramabadIran

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