Diagnosis of congenital toxoplasmosis by polymerase chain reaction

Blood Levels of Oxidant/Antioxidant Parameters in Rats Infected with Toxoplasma gondii

Toxoplasmosis is a common parasitic infection in the world. Since increased free radicals and oxidative stress are reported in many parasitic diseases the purpose of the present study was to evaluate the oxidative stress in acute and chronic toxoplasmosis. RH strains of Toxoplasma tachyzoites were used in the present study. Twenty-five female rats were infected with the parasite while 25 other rats were as the control group that received normal saline. Zero-, 5-, 7-, 10-, and 45-day postinfection (DPI) blood samples were taken. Some parameters related to oxidant and antioxidants such as antioxidant enzymes, malondialdehyde, and total antioxidant capacity were measured. On day 7 after infection, GPX activity and GSH level were significantly increased and in the mentioned day the amount of total antioxidant capacity was significantly reduced. In other cases, there were no significant differences between the groups in different days. Overall, based on the results it seems that, on day 7 after infection, in infected rats responses to oxidative stress were triggered and led to decrease of total antioxidant capacity. Furthermore, glutathione was increased to cope with stress. It seems that probably antioxidant defense system entered the infection to the chronic phase and changed the parasites stage.

Molecular diagnosis of Toxoplasma gondii infection in Libya

Background

Toxoplasma gondii infections are prevalent in humans and animals throughout Libya. Current diagnosis is based on detection of Toxoplasma-specific IgM and IgG. In this study, we established and optimized a diagnostic PCR assay for molecular diagnosis of T. gondii in Libya.

Methods

From January to December, 2010, 177 blood and serum samples were collected from suspected patients. This includes: 140 women who have had spontaneous abortions, 26 HIV-positive patients, nine patients with leukemia and lymphoma, and two infants with ocular infection. Samples were screened for anti-Toxoplasma IgG and IgM antibodies before DNA extraction. The surface antigen gene 2 (SAG2) was targeted in a semi-nested PCR to amplify a 999 bp and a 614 bp fragment in the first and the second run respectively.

Results

A total of 54/140 (38.5 %) women who have had spontaneous abortions, 23/26 (88 %) HIV patients, 6/9 (66.6 %) of the leukaemia and lymphoma patients, and one child with ocular infection were seropositive for anti-Toxoplasma IgG and/or IgM. Genomic DNA was extracted from 38 selected seropositive samples. The PCR was sensitive enough to detect DNA concentration of 12 ng/μL. PCR analysis was performed for 38 selected seropositive patients (16 women who have had spontaneous abortions, 15 positive HIV patients, six leukaemia patients and one child with ocular infection). Our designed primers were successfully amplified in 22/38 (57.9 %) samples; 5/12 (35.7 %) from serum and 17/26 (65.8 %) from whole blood samples. All PCR positive samples were IgG-positive except two samples which were IgM and IgG & IgM-positive serum samples respectively. The semi-nested PCR confirmed five more samples. These included two leukaemia and two HIV-positive whole blood samples and one serum sample from an aborted woman.

Conclusion

The ability of PCR to diagnose active toxoplasmosis is needed in immunocompromised patients and congenital toxoplasmosis cases, especially when serological techniques fail. For the first time in Libya, we established and optimized semi-nested PCR of SAG2 gene. The developed PCR method was able to detect as little as 12 ng/μL of T. gondii DNA and was useful to diagnose the diseases in women who have had spontaneous abortions, HIV-positive patients, patients with leukemia and lymphoma, and infants with ocular infection.

Toxoplasmosis-associated abortion and stillbirth in Tehran, Iran

OBJECTIVES

This study was aimed to evaluate the role of toxoplasmosis in etiology of abortion and stillbirth based on molecular and serological techniques.

MATERIAL AND METHODS

A total of 110 pregnant women with abortion and stillbirth were enrolled as the case group, and 110 pregnant women with normal delivery were enrolled as the control group. Serological and molecular detections of Toxoplasma gondii were assessed by ELISA and PCR methods.

RESULTS

The seroprevalence of IgG was 25.5% in the case group (26.8% in abortion and 21.4% in stillbirth) and 26.4% in the control group. IgM seropositivity was detected in 2.7% of the case group (3.6% in abortion and 0% in stillbirth) and 0.9% of the control group (p = 0.37). Toxoplasma gondii DNA was detected in 6.4% of the case group (7.3% in abortion and 3.6% in stillbirth) and 1.8% of the control group by PCR (p = 0.17). The major risk factor of congenital toxoplasmosis was the history of eating undercooked meat (p = 0.06).

CONCLUSION

Results of this study revealed that the rate of PCR positive in women with abortion and stillbirth was 3.7 times higher than that in normal delivery, but the difference was not statistically significant. These findings suggest that toxoplasmosis can be involved in etiology of abortion and stillbirth.