The sodium hydrogen exchanger 1 (NHE1), which functions in maintaining the ratio of Na+ and H+ ions, is widely distributed in cell plasma membranes. It plays a prominent role in pH balancing, cell proliferation, differentiation, adhesion, and migration. However, its exact subcellular location and biological functions in Toxoplasma gondii are largely unclear. In this study, we cloned the C-terminal sequence of T. gondii NHE1 (TgNHE1) incorporating the C-terminal peptide of NHE1 (C-NHE1) into the pGEX4T-1 expression plasmid. The peptide sequence was predicted to have good antigenicity based on the information obtained from an immune epitope database. After induction of heterologous gene expression with isopropyl-b-D-thiogalactoside, the recombinant C-NHE1 protein successfully expressed in a soluble form was purified by glutathione sepharose beads as an immunogen for production of a rabbit polyclonal antiserum. The specificity of this antiserum was confirmed by western blotting and immunofluorescence. The antiserum could reduce T. gondii invasion into host cells, indicated by the decreased TgNHE1 expression in T. gondii parasites that were pre-incubated with antiserum in the process of cell entry. Furthermore, the antiserum reduced the virulence of T. gondii parasites to host cells in vitro, possibly by blocking the release of Ca2+. In this regard, this antiserum has potential to be a valuable tool for further studies of TgNHE1.
Animals ; Cell Line ; Immune Sera/genetics/immunology/*metabolism ; Male ; Mice ; Protozoan Proteins/genetics/*metabolism ; Rabbits ; Recombinant Proteins/immunology ; Sheep ; Sodium-Hydrogen Antiporter/genetics/immunology/*metabolism ; Toxoplasma/genetics/immunology/*metabolism ; Toxoplasmosis/parasitology/prevention & control

The aim of this cross sectional case control study was to examine the serofrequency and serointensity of Toxoplasma gondii (Tg) IgG, IgM, and DNA among patients with schizophrenia. A total of 101 patients with schizophrenia and 55 healthy controls from Sungai Buloh Hospital, Selangor, Malaysia and University Malaya Medical Center (UMMC) were included in this study. The diagnosis of schizophrenia was made based on the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV). The presence of Tg infection was examined using both indirect (ELISA) and direct (quantitative real-time PCR) detection methods by measuring Tg IgG and IgM and DNA, respectively. The serofrequency of Tg IgG antibodies (51.5%, 52/101) and DNA (32.67%, 33/101) among patients with schizophrenia was significantly higher than IgG (18.2%, 10/55) and DNA (3.64%, 2/55) of the controls (IgG, P=0.000, OD=4.8, CI=2.2-10.5; DNA, P=0.000, OD=12.9, CI=2.17-10.51). However, the Tg IgM antibody between patients with schizophrenia and controls was not significant (P>0.005). There was no significant difference (P>0.005) in both serointensity of Tg IgG and DNA between patients with schizophrenia and controls. These findings have further demonstrated the strong association between the active Tg infection and schizophrenia.
Adolescent ; Adult ; Aged ; Antibodies, Protozoan/*blood ; Case-Control Studies ; Cross-Sectional Studies ; DNA, Protozoan/*blood ; Enzyme-Linked Immunosorbent Assay ; Female ; Humans ; Immunoglobulin G/blood ; Immunoglobulin M/blood ; Malaysia ; Male ; Middle Aged ; Real-Time Polymerase Chain Reaction ; Schizophrenia/*complications ; Seroepidemiologic Studies ; Toxoplasma/classification/genetics/immunology/*isolation & purification ; Toxoplasmosis/*epidemiology/immunology/*parasitology ; Young Adult

The aim of this cross sectional case control study was to examine the serofrequency and serointensity of Toxoplasma gondii (Tg) IgG, IgM, and DNA among patients with schizophrenia. A total of 101 patients with schizophrenia and 55 healthy controls from Sungai Buloh Hospital, Selangor, Malaysia and University Malaya Medical Center (UMMC) were included in this study. The diagnosis of schizophrenia was made based on the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV). The presence of Tg infection was examined using both indirect (ELISA) and direct (quantitative real-time PCR) detection methods by measuring Tg IgG and IgM and DNA, respectively. The serofrequency of Tg IgG antibodies (51.5%, 52/101) and DNA (32.67%, 33/101) among patients with schizophrenia was significantly higher than IgG (18.2%, 10/55) and DNA (3.64%, 2/55) of the controls (IgG, P=0.000, OD=4.8, CI=2.2-10.5; DNA, P=0.000, OD=12.9, CI=2.17-10.51). However, the Tg IgM antibody between patients with schizophrenia and controls was not significant (P>0.005). There was no significant difference (P>0.005) in both serointensity of Tg IgG and DNA between patients with schizophrenia and controls. These findings have further demonstrated the strong association between the active Tg infection and schizophrenia.
Adolescent ; Adult ; Aged ; Antibodies, Protozoan/*blood ; Case-Control Studies ; Cross-Sectional Studies ; DNA, Protozoan/*blood ; Enzyme-Linked Immunosorbent Assay ; Female ; Humans ; Immunoglobulin G/blood ; Immunoglobulin M/blood ; Malaysia ; Male ; Middle Aged ; Real-Time Polymerase Chain Reaction ; Schizophrenia/*complications ; Seroepidemiologic Studies ; Toxoplasma/classification/genetics/immunology/*isolation & purification ; Toxoplasmosis/*epidemiology/immunology/*parasitology ; Young Adult

The breeding of domestic rabbits (Oryctolagus cuniculus) for human consumption has a long tradition in China. Infections that can affect the production of meat or even be transmitted from animals to humans are important to monitor, especially for public health reasons as well as for their impact on animal health. Thus, a total of 1,132 domestic rabbit sera from 4 regions in China were collected for serological screening for Encephalitozoon cuniculi and for Toxoplasma gondii by ELISA and modified agglutination test (MAT), respectively. Antibodies to E. cuniculi were detected in 248/1,132 (21.9%) sera tested while antibodies against T. gondii revealed a seroprevalence of 51/1,132 (4.5%). We believe that the present results are of epidemiological implications and public health importance due to the acknowledged susceptibility of humans to E. cuniculi and T. gondii infections. Therefore, routine screening tests of domestic rabbits are proposed considering the zoonotic potential of these parasites.
Animals ; Animals, Domestic/blood/microbiology/parasitology ; Antibodies, Fungal/*blood ; Antibodies, Protozoan/*blood ; China/epidemiology ; Encephalitozoon cuniculi/*immunology/isolation & purification ; Encephalitozoonosis/blood/microbiology/*veterinary ; Female ; Male ; Rabbits/blood/microbiology/parasitology ; Seroepidemiologic Studies ; Toxoplasma/*immunology/isolation & purification ; Toxoplasmosis, Animal/*blood/parasitology

Mouse models of chronic toxoplasmosis and atopic dermatitis (AD) were combined to clarify the effect of opportunistic Toxoplasma gondii infection on the development of AD. AD was induced as a chronic contact hypersensitivity (CHS) with repeated challenge of 2,4,6-trinitro-1-chlorobenzene (TNCB) on the dorsal skin of mice. TNCB induced skin thickness increases in both normal and toxoplasmic mice. The changing patterns were different from the sigmoidal which saturated at 20 days in normal mice to the convex saturated at 12 days in toxoplasmic mice with the crossing at 18 days. Compared to normal mice, toxoplasmic mice presented CHS more severely in earlier times and then moderately in later times. These data suggest that host immune modification by T. gondii infection enhances CHS in early times of atopic stimulation but soothes the reaction of CHS in later times in mouse model.
Animals ; Dermatitis, Contact/*immunology/parasitology ; Disease Models, Animal ; Female ; Humans ; Mice ; Mice, Inbred BALB C ; Picryl Chloride/adverse effects ; Skin/immunology/parasitology ; Toxoplasmosis/*immunology/parasitology

Toxoplasmosis, caused by Toxoplasma gondii, is a parasitic zoonosis with worldwide distribution. The present study investigated the prevalence of T. gondii in dogs in Zhanjiang city, southern China, using both serological and molecular detection. A total of 364 serum samples and 432 liver tissue samples were collected from the slaughter house between December 2012 and January 2013 and were examined for T. gondii IgG antibody by ELISA and T. gondii DNA by semi-nested PCR based on B1 gene, respectively. The overall seroprevalence of T. gondii IgG antibody was 51.9%, and T. gondii DNA was detected in 37 of 432 (8.6%) liver tissue samples. These positive DNA samples were analyzed by PCR-RFLP at 3'- and 5'-SAG2. Only 8 samples gave the PCR-RFLP data, and they were all classified as type I, which may suggest that the T. gondii isolates from dogs in Zhanjiang city may represent type I or type I variant. This study revealed the high prevalence of T. gondii infection in dogs in Zhanjiang city, southern China. Integrated measures should be taken to prevent and control toxoplasmosis in dogs in this area for public health concern.
Animals ; Antibodies, Protozoan/blood ; China/epidemiology ; Dog Diseases/epidemiology/*parasitology ; Dogs ; Female ; Genotype ; Liver/parasitology ; Male ; Toxoplasma/classification/genetics/immunology/*isolation & purification ; Toxoplasmosis, Animal/blood/epidemiology/*parasitology

Although Toxoplasma gondii infection in primary school children has been investigated in many countries, limited surveys have been available in primary school children in China. In the present study, we report the seroprevalence of T. gondii infection in primary school children in Shandong province, China. Sera from 6,000 primary school children were evaluated for T. gondii antibodies with ELISA. The overall seroprevalence of T. gondii infection was 16.0% (961/6,000), of which 14.5% (870/6,000) were positive for anti-T. gondii IgG antibodies, 3.4% (206/6,000) positive for IgM, and 1.9% (115/6,000) were positive for both IgG and IgM. The results of the present investigation indicated a high seroprevalence of T. gondii infection in primary school children in Shandong province, China. Therefore, effective measures should be taken to prevent and control T. gondii infection in primary school children in this province. To the best of our knowledge, this is the first report of T. gondii seroprevalence in primary school children in Shandong province, China.
Antibodies, Protozoan/blood ; Child ; China/epidemiology ; Female ; Humans ; Male ; Seroepidemiologic Studies ; Students ; Toxoplasma/genetics/immunology/*isolation & purification ; Toxoplasmosis/blood/*epidemiology/*parasitology

Toxoplasma gondii is an apicomplexan parasite with a broad host range of most warm-blooded mammals including humans, of which one-thirds of the human population has been infected worldwide which can cause congenital defects, abortion, and neonatal complications. Here, we developed a rapid diagnostic test (RDT) for T. gondii infection. Antigenic N-terminal half of the major surface antigen (SAG1) was linked with intrinsically unstructured domain (IUD) of dense granule protein 2 (GRA2). The recombinant GST-GRA2-SAG1A protein was successfully expressed and purified as 51 kDa of molecular weight. Furthermore, antigenicity and solubility of the rGST-GRA2-SAG1A protein were significantly increased. The overall specificity and sensitivity of GST-GRA2-SAG1A loaded RDT (TgRDT) were estimated as 100% and 97.1% by comparing with ELISA result which uses T. gondii whole cell lysates as the antigen. The TgRDT tested with Uganda people sera for field trial and showed 31.9% of seroprevalence against T. gondii antibody. The TgRDT is proved to be a kit for rapid and easy to use with high accuracy, which would be a suitable serodiagnostic tool for toxoplasmosis.
Adolescent ; Adult ; Amino Acid Sequence ; Antibodies, Protozoan/*blood ; Antigens, Protozoan/genetics/*immunology ; Child ; Child, Preschool ; Female ; Humans ; Infant ; Male ; Molecular Sequence Data ; Protozoan Proteins/genetics/*immunology ; Recombinant Fusion Proteins ; Reproducibility of Results ; Republic of Korea/epidemiology ; Sensitivity and Specificity ; Serologic Tests ; Time Factors ; Toxoplasma/genetics/*immunology/isolation & purification ; Toxoplasmosis/*diagnosis/epidemiology/parasitology ; Uganda/epidemiology ; Young Adult

In recent years, worldwide surveys of Toxoplasma gondii infection in dogs have been reported. However, only limited surveys of T. gondii infection in police dogs have been available, including China. In the present study, we report the seroprevalence of T. gondii in police dogs in Shenyang, northeastern China. Sera from 291 police dogs were examined for T. gondii antibodies with the modified agglutination test (MAT), and 30.9% animals were tested seropositive. The results of the present study indicated a relatively high prevalence of T. gondii infection in police dogs in Shenyang, China.
Agglutination Tests/veterinary ; Animals ; Antibodies, Protozoan/*blood ; China/epidemiology ; Dog Diseases/*epidemiology/parasitology ; Dogs ; Female ; Male ; Seroepidemiologic Studies ; Toxoplasma/*immunology/isolation & purification ; Toxoplasmosis, Animal/*epidemiology/parasitology

Toxoplasma gondii is one of the major agents of infectious abortions and due to its worldwide distribution can threat healthy pregnant women who had no previous exposure to this parasite. The present study was designed to investigate the contribution of T. gondii to spontaneous abortions in Zanjan, Northwest of Iran, using ELISA method. Blood Samples were collected from 264 mothers referred to the provincial hospitals of Zanjan due to spontaneous abortion. The sera were isolated and subjected to evaluate the anti-Toxoplasma IgG, IgM and IgA antibodies. The results showed IgG positive (IgG+) in 99 cases (37.5%). A total of 68 women (25.8%) showed seroconversion with IgM or IgA or both IgM and IgA. They included: IgM+ in 21 (8.0%), IgA+ in 23 (8.7%) and both IgM+ and IgA+ in 24 (9.1%) subjects. In 23 cases, positive titers of IgM and IgG were accompanied. In general, the analysis of anti-Toxoplasma antibody patterns, showed that about 17% of the spontaneous abortions were associated with serological patterns of acute infection. According to these findings, a considerable proportion of spontaneous abortions can be attributed to T. gondii in the study area.
Abortion, Spontaneous/immunology/*parasitology ; Antibodies, Protozoan/*blood ; Cross-Sectional Studies ; Enzyme-Linked Immunosorbent Assay ; Female ; Humans ; Immunoglobulin A/blood ; Immunoglobulin G/blood ; Immunoglobulin M/blood ; Iran/epidemiology ; Mothers ; Pregnancy ; Pregnancy Complications, Parasitic/*immunology/parasitology ; Toxoplasma/*immunology ; Toxoplasmosis, Congenital/*immunology/parasitology