Background: TOXOPLASMA GONDII infects a wide range of animals; felines are definitive hosts and other animals including the dogs are intermediate hosts. The aim of this study was to determine the seroprevalence of T. GONDII infection in dogs in Tehran, capital of Iran and to investigate possible associated risk factors.Methods: Three hundreds ninety six serum samples were collected during 2007-8 from the dogs.Collected samples were tested using an indirect fluorescent antibody test (IFAT) in dilutions of 1: 16 and more. All procedures were carried out in Shahrekord University, Iran. All the data were analyzed using SPSS software, qui square test with confidence interval of 0.95.Results: From evaluated samples, 89 (22.47%) were positive in titers of at least 1: 16. further evaluations in other dilutions showed positive results in dilutions of maximum 1: 16, 1: 32, 1: 64, 1: 128 and 1: 256 in 38, 29, 15, 2 and 5 dogs respectively. Investigation of the role of risk factors showed no sex predisposition while infection rate was significantly higher in dogs older than one year old. Living places were of significant importance; infection rate was significantly higher in stray or guard dogs in compare with household dogs (P<0.05).Conclusion: Relatively high seroprevalence of T. GONDII infection in dogs in Tehran shows high environmental contamination. It is recommended that the dogs with suspected clinical signs be tested for T. GONDII infection.

Introduction: Toxoplasmosis is a parasitic infection caused by the protozoan TOXOPLASMA GONDII; it leads to serious medical problems in congenitally-infected and immunocompromised individuals, while it is quite harmless in immunocompetent individuals. TOXOPLASMA tissue cyst matrix protein (MAG1) induces early humoral and cell-mediated immune responses. Previous studies suggested recombinant MAG1 as a promising antigen for serodiagnosis of TOXOPLASMA infection.Methods: A DNA fragment encoding mag1, comprising amino acids 50 to 207, was amplified from T. GONDII RH strain and cloned in prokaryotic expression plasmid pET-15b (+). Recombinant MAG1 was expressed in Escherichia coli, and highly purified in a single step by immobilized metal ion affinity chromatography.Results: The cloned DNA fragment was sequenced and showed 100% similarity with the published sequences available in GenBank Database. The results indicated proper antigenicity of recombinant MAG1. In Western blot analysis, purified protein showed a much stronger reactivity with sera from patients with acute TOXOPLASMA infection, compared to sera from chronic infection.Conclusion: MAG1 protein, alone or in combination with other acute-phase markers might be useful in discriminating acute/reactivated TOXOPLASMA infections from chronic forms.

Aims: Toxoplasmosis is the disease caused by an intercellular protozoan called TOXOPLASMA GONDII. TOXOPLASMA has global expansion and infects a wide range of warm blood animals.Presence of parasites inside cells affects cellular various activities and causes changes in cellular mechanisms.This study was carried out in order to evaluate the changes in testosterone level due toTOXOPLASMA GONDII.Materials & Methods: This cohort study was performed on individuals who referred to one of Tehran military hospitals in year 2009.180 people were selected by simple random sampling.5 ml of blood was taken from individuals and 1 ml serum was separated and used in order to determine toxoplasmosis infection and testosterone concentration by ELISA method. Hirsutism, hair loss, weight and height were also evaluated and documented. The results were analyzed by SPSS 16 software using independent t-test and Pearson correlation.Results: Of 180 serum samples (73 females and 107 males), 24femals (13/33%) and 39 males (21/66%) had anti TOXOPLASMAIgG antibody. The results showed significant correlation between TOXOPLASMA and testosterone increase in women (p=0.002), testosterone increase in men (p<0.0001), hair loss in women (p=0.002), hirsutism in women (p=0.001) and height increase in women and men, but there was no significant correlation between weight andTOXOPLASMA infection in women and men.Conclusion: There is a significant correlation between TOXOPLASMA infection and serum increase of testosterone, hirsutism, hair loss and height in patients. Results of this research can be beneficial in evaluation of disease symptoms and treatment protocol of toxoplasmosis patients for research centers and physicians.

Objective: Evaluation of the effects of TOXOPLASMA GONDII infection on spermatogenesis in male rats.Materials and Methods: The RH strain of T. GONDII tachyzoites were injected interaperitoneally in an infected group of 35 rats, while 21 rats were used as controls. Each ten days from 10- 70 days of post-infection (PI), 5 rats from infected group and 3 rats from control group were scarified. The percentage of body weight to testis weight ratio (BTR) as well as sperm parameters and fructose levels in seminal vesicles and coagulating glands (SVCG) were investigated. An IgG ELISA kit was designed for serologic diagnosis of infection in the rats.Results: All rats injected with T. GONDII tachyzoites were infected from 10-70 PI. Sperm motility from 10-70 PI, sperm viability from 10-60 PI and sperm concentration from 20-60 PI were significantly decreased in the infected group (P<0.05); sperm abnormality was significantly increased in the infected group on days 30, 40 and 50 PI (P<0.05). BTR in the infected group was not significantly changed compared to control group (P>0.05). Fructose level in SVCG in the infected group was significantly decreased on days 10-50 PI (P<0.05) compared to control.Conclusion: According to the results, toxoplasmosis can cause impermanent impairment on the spermatogenesis in the male rats.

Background: TOXOPLASMA GONDII, the coccidian protozoan parasite with worldwide distribution, is the agent of toxoplasmosis. The disease is life threatening in congenital form and in immunocompromised patients. The present study was carried out in 2016 to evaluate the in vitro effects of nanosilver colloid on tachyzoites and bradyzoites of T. GONDII, RH and Tehran strains. Methods: Different concentrations (5, 10, 20 ppm) of nanosilver colloid were added to tachyzoites of T. GONDII, RH strain (type I) and bradyzoites and tissue cysts of T. GONDII, Tehran strain (type II) and incubated for 30, 60, 90 and 120 minutes. The mortality rates of tachyzoites and bradyzoites were evaluated by trypan blue dye and MTT assay. Then SEM carried out to show the changes between control and exposed parasites. Results: The greatest mortality rate was seen in 20 ppm concentration and after 120 minutes of exposure. By electron microscopy, the structural changes were seen in tachyzoites of RH and tissue cyst of Tehran strain in comparison with control groups. Conclusion: Nanosilver colloid was effective on both tachyzoites and bradyzoites of T. GONDII, RH and Tehran strains.