title: Design of Indigenous ELISA Using Tachyzoites from the RH Strain ofToxoplasma gondiiand Comparison with Commercial Kits in Ahvaz, Southwest of Iran, 2015.
abstract: BACKGROUND
  Toxoplasma gondiiis one of the most common causes of latent infections in humans worldwide. Detecting anti-Toxoplasmaantibodies in serum using serological tests is a common method to diagnose toxoplasmosis.
  
  
  OBJECTIVE
  In the present study, an indigenous ELISA kit was prepared using tachyzoites from the RH strain ofT. gondii, and its sensitivity and specificity were compared with those of commercial kits.
  
  
  METHODS
  To produce antigens, 0.02 mL of locally isolatedT. gondiiRH strain parasites along with 109tachyzoites were injected into the peritoneal cavities of 50 laboratory mice (BALB/C). Parasites were collected after 4 days. After filtering and washing, the concentration of protein in sonicated tachyzoites was calculated using the Lowry protein assay. The dilution of antigen, serum and alkaline phosphatase conjugate was assessed in designing an indigenous ELISA method; then ELISA was performed based on these dilutions, and its sensitivity was determined using 200 serum samples. In addition, the specificity of the assay was evaluated using 40 serum samples from patients with tuberculosis, leukemia or hydatid cyst.
  
  
  RESULTS
  Indigenous ELISA was used to examine 100 serum samples containing anti-T. gondiiIgG, with a sensitivity of 98% (commercial kits: 100%). Another 100 serum samples containing anti-T. gondiiIgM were also tested, with a sensitivity of 99% (commercial kits: 100%). When 40 serum samples from patients with leukemia, hydatid cyst or tuberculosis were examined using anti-T. gondiiIgG, the specificity was 100%, identical to commercial kits. However, the specificity of a similar test with anti-T. gondiiIgM was just 28.6% for serum samples from leukemia patients, 21.4% for hydatid cyst and 16.7% for tuberculosis.
  
  
  CONCLUSIONS
  We found that purified locally isolated soluble crude antigens of the RH strain ofT. gondiifrom the peritoneal cavity of mice may be one of the most promising antigens for detection of human toxoplasmosis in routine screening.
authors.affiliation: Department of Medical Parasitology, Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, IR Iran.
authors.forename: Niloofar
authors.initials: N
authors.lastname: Mohammadpour
authors.affiliation: Department of Medical Parasitology, Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, IR Iran; Health Research Institute, Infectious and Tropical Diseases Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, IR Iran.
authors.forename: Jasem
authors.initials: J
authors.lastname: Saki
authors.affiliation: Health Research Institute, Infectious and Tropical Diseases Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, IR Iran.
authors.forename: Abdollah
authors.initials: A
authors.lastname: Rafiei
authors.affiliation: Department of Immunology, School of Medicine , Ahvaz Jundishapur University of Medical Sciences, Ahvaz, IR Iran.
authors.forename: Ali
authors.initials: A
authors.lastname: Khodadadi
authors.affiliation: Department of Medical Parasitology, Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, IR Iran.
authors.forename: Mehdi
authors.initials: M
authors.lastname: Tavalla
authors.affiliation: Department of Epidemiology and Biostatistics, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, IR Iran.
authors.forename: Bahman
authors.initials: B
authors.lastname: Cheraghian
keywords: Commercial Kits; Designing; Indigenous ELISA; Iran; Tachyzoites RH Strain; Toxoplasma gondii