Saeedeh Shojaee

Background: Toxoplasmosis is an infectious disease caused by the coccidian protozoan parasite Toxoplasma gondii. The infection is life-threatening in congenital form because of transmission of the parasite from mother to fetus. In order to investigate the prevalence of congenital toxoplasmosis, the present study was performed for detection of IgG and IgM antibodies in cord blood samples of newborns by ELISA method in Tehran, Iran. Methods: This cross-sectional survey was carried out on 1000 cord blood samples collected from Shahid Mostafa Khomeini Hospital in Tehran, Iran in 2015. Sera were separated and evaluated for the presence of IgG and IgM antibodies against T. gondii by ELISA method. At the same time, whole cord blood samples were stored at -20 °C for complementary PCR test. Results: From 1000 cord blood serum samples 198 cases (19.8%) were positive for anti T. gondii IgG antibody. IgG positive samples were examined for IgM antibody, among them 1 sample had borderline levels of IgM antibody. PCR was performed for this sample but no positive result was seen. Conclusion: Although congenital toxoplasmosis is of importance, no acute form of infection was seen in pregnant women in this study.

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.

Background: Toxoplasma gondii is an intracellular protozoan parasite distributed worldwide. Although the infection is benign in immunocompetent individuals, it is life threatening and complicated in immunocompromised patients and fetuses of pregnant women who received their first exposure to T. gondii during the pregnancy. Prolactin (PRL) is a hormone that is secreted by the pituitary gland, and it is confirmed that it plays a role in the immune system. The present study was carried out to assess the possible relation between serum PRL levels and Toxoplasma infection frequency in human. Methods: In this cross-sectional study, 343 serum samples (240 from women and 103 from men) were collected from individuals who were referred for PRL checking in laboratories of Karaj, Iran. Blood samples were collected, and sera were separated and analyzed for the detection of anti-Toxoplasma IgG antibody by ELISA method. The levels of PRL were measured by Roche Elecsys 2010 analyzer, electrochemiluminescence technology. Results: Of 343 sera, 110 samples (32%) consisting of samples from 42 men and 68 women had anti-T. gondii IgG antibody. The prevalence of T. gondii infection in women with high PRL levels was lower than that in the comparison group with normal levels of PRL and the relationship between these two parameters was statistically significant (P=0.016). In women with hyperprolactinemia, by increasing of PRL levels, the prevalence of T. gondii infection was reduced. Conclusion: The results of the current study confirmed the previous studies based on immunoregulatory role of PRL and indicated that high levels of PRL could be related to Toxoplasma seronegativity in women.

Background: The aim of this study was to prepare curcumin nanoemulsion (CR-NE) to solve the problems associated with poor water solubility and low bioavailability of CR and to test its efficiency in the treatment of acute and chronic toxoplasmosis in mouse models. Materials and methods: CR-NE 1% was prepared using spontaneous emulsification by soybean as oil phase; a mixture of Tween 80 and Tween 85 as surfactant; ethanol as cosurfactant and distilled water. Particle size and zeta potential of NE were assessed using Nano-ZS90 dynamic light scattering. Stability testing of NE was assessed after storage for 2 months at room temperature. In vivo experiments were carried out using 50 BALB/c mice inoculated with virulent RH strain (type I) and 50 BALB/c mice inoculated with avirulent Tehran strain (type II) of Toxoplasma gondii and treated with CR-NE (1% w/v), CR suspension (CR-S, 1% w/v), and NE without CR (NE-no CR). Results: The mean particle size and zeta potential of CR-NE included 215.66±16.8 nm and -29.46±2.65 mV, respectively, and were stable in particle size after a three freeze–thaw cycle. In acute phase experiment, the survival time of mice infected with RH strain of T. gondii and treated with CR-NE extended from 8 to 10 days postinoculation. The differences were statistically significant between the survival time of mice in CR-NE-treated group compared with negative control group (PP T. gondii Tehran strain and treated with CR-NE compared with that in negative control group (PP Conclusion: Results from the current study showed the potential of CR-S and CR-NE in treatment of acute and chronic toxoplasmosis in mouse models for the first time. However, CR-NE was more efficient than CR-S, and it seems that CR-NE has a potential formula for the treatment of acute and chronic toxoplasmosis, especially in those with latent bradyzoites in brain.

Toxoplasma gondii is a protozoan parasite with worldwide distribution, infecting a broad-range of humans and warm-blooded animals. In the current study, role of this parasite on secondary sex ratio and risk of miscarriage was investigated. In this cross-sectional study, 850 cord blood samples were collected in Tehran, Iran, 2014–2015. Enzyme-linked immunosorbent assay (ELISA) was used to assess anti-Toxoplasma IgG in samples. Information such as sex of the neonates and age, number of previous pregnancies and history of miscarriage of the mothers were recorded in questionnaires. Logistic regression analysis was used to assess the possible relationship between the latent toxoplasmosis and the highlighted parameters. Logistic regression analysis showed that the odds of having a male neonate in seropositive women is nearly 64% higher than that in seronegative women (OR = 1.64, CI95 = 1.16–2.33, P = 0.005). The odds ratio of having male neonate increased to 2.10 (CI95 = 1.24–3.57, P = 0.006) in high-titer seropositive women, compared to that in seronegative control group. The odds of having a miscarriage history was approximately two and a half times greater in seropositive women than in seronegative ones (OR = 2.45, CI95 = 1.56–3.87, P < 0.001). The odds ratio of having miscarriage increased to 2.76 (CI95 = 1.61–4.73, P < < .001) in low-titer seropositive women, compared to that in seronegative control group. Results of the current study have shown that T. gondii infection affects secondary sex ratio in human offspring and can be addressed as one of the major miscarriage causes in women.

Latent toxoplasmosis modifies various hormones and behaviors in infected hosts and possibly involves in etiology of different neurologic and psychiatric disorders. The aim of the current study was to assess possible associations between latent toxoplasmosis and testosterone concentration in Toxoplasma infected and free subjects. Briefly, 18–49 year-old participated in the study. After collected blood samples, sera were analyzed for the detection of anti-Toxoplasma IgG antibody. Totally, 76 positive sera were selected as study group (38 from men and 38 from women) and a same number of negative sera as control group. Comparison of testosterone concentrations and control groups showed that testosterone concentration in study group was higher than that in control group with statistically significant difference (P = 0.024 and P = 0.043 for men and women, respectively). Significant differences were found in testosterone concentrations and anti-Toxoplasma IgG antibody levels in study and control groups (P < 0.05). Toxoplasmosis can affect the mean concentration of serum testosterone in human. Alteration of testosterone during latent toxoplasmosis can result in alterations in behavioral, physiologic and immunological parameters in long time.

In the current study, performance of electrochemiluminescence immunoassay (ECLIA) in detection of anti-toxoplasma IgG in human sera was compared with that of enzyme-linked immunosorbent assay (ELISA). Furthermore, performance of an in house Dot-ELISA in detection of anti-toxoplasma IgG was compared with that of ECLIA and ELISA. In total, 219 human sera were tested to detect anti-toxoplasma IgG using Dynex DS2® and Roche Cobas® e411 Automated Analyzers. Discordant results rechecked using immunofluorescence assay (IFA). Then, sera were used in an in house Dot-ELISA to assess toxoplasma-specific IgG. Of the 219 samples, two samples were found undetermined using ECLIA but reactive using ELISA. Using IFA, the two sera were reported unreactive. Furthermore, two samples were found reactive using ECLIA and unreactive using ELISA. These samples were reported reactive using IFA. The overall agreement for the two former methods was 98% (rZ0.98.1; P < 0.001). The intrinsic parameters calculated for in house Dot-ELISA included sensitivity of 79.5, specificity of 78.2, and accuracy of 78.9%, compared to ECLIA and ELISA. Positive and negative predictive values included 82.9 and 74.2%, respectively. A 100% sensitivity was found in in house Dot-ELISA for highly reactive sera in ECLIA and ELISA. ECLIA is appropriate for the first-line serological screening tests and can replace ELISA due to high speed, sensitivity, and specificity, particularly in large laboratories. Dot-ELISA is a rapid, sensitive, specific, cost-effective, user-friendly, and field-portable technique and hence can be used for screening toxoplasmosis, especially in rural fields or less equipped laboratories.

Background: Natural polysaccharides such as chitosan (CS) are widely used as antimicrobial agents. In recent years, and considering that CS has a strong antimicrobial potential, interest has been focused on antimicrobial activity of chitosan nanoparticles (CS NPs). The main factors affecting the antibacterial activity of chitosan include molecular weight (MW) and concentration. In this regard, the aim of this study was to produce various MWs and concentrations of CS NPs, through the ionic gelation method, and investigate their potential anti-parasitic activity against tachyzoites of Toxoplasma gondii RH strain. Materials and methods: The MWs and degree of deacetylation of the CS were characterized using viscometric and acid–base titration methods, respectively. The efficacy of various MWs and concentrations of NPs was assessed by performing in vitro experiments for tachyzoites of T. gondii RH strain, such as MTT assay, scanning electron microscopy, bioassay in mice and PCR. In vivo experiment was carried out in BALB/c mice which were inoculated with tachyzoites of T. gondii RH strain and treated with various MWs of CS NPs. Results: The results of in vitro and in vivo experiments revealed that anti-Toxoplasma activity strengthened as the CS NPs concentration increased and the MW decreased. In vitro experiment showed 100% mortality of tachyzoites at 500 and 1,000 ppm concentrations of low molecular weight (LMW) CS NPs after 180 min and at 2,000 ppm after 120 min. Furthermore, a 100% mortality of tachyzoites was observed at 1,000 and 2,000 ppm concentrations of medium molecular weight (MMW) CS NPs and at 2,000 ppm concentration of high molecular weight (HMW) CS NPs after 180 min. Growth inhibition rates of tachyzoites in peritoneal exudates of mice receiving low, medium and high MWs of CS NPs were found to be 86%, 84% and 79% respectively, compared to those of mice in sulfadiazine treatment group (positive control). Conclusion: Various MWs of CS NPs exhibited great anti-Toxoplasma efficiency against tachyzoites of RH strain, with the greatest efficacy shown by LMW CS NPs in both experiments. It seems that CS NPs can be used as an alternative natural medicine in the treatment of toxoplasmosis.

Toxoplasmosis is an infectious disease caused by the coccidian parasite Toxoplasma gondii. Diagnosis is based on serological methods with detection of specific IgG and IgM antibodies. The present study was performed to compare the sensitivity and specificity of soluble antigen of T. gondii, RH strain obtained from mice and cell culture in ELISA method. Tachyzoites of T. gondii, RH strain that inoculated in mice peritoneum were collected. At the same time, tachyzoites were harvested from HeLa cell culture that infected with the parasite. Soluble antigen was prepared and ELISA method performed on 100 serum samples that were collected from different laboratories in Tehran, Iran. Commercial Trinity kit was used as gold standard. The sensitivity and specificity of T. gondii soluble antigen were higher in antigens that obtained from cell culture in comparison with mice peritoneum. T. gondii cell culture derived antigen has high sensitivity and specificity in ELISA test.