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

Toxoplasmosis is an important zoonotic disease that can cause abortion in humans and animals. The aim of this study was isolation and subsequent genotyping of Toxoplasma gondii isolates in ovine aborted fetuses. During 2012-2013, 39 ovine aborted fetuses were collected from sheep flocks in Khorasan Razavi Province, Iran. The brain samples were screened for detection of the parasite DNA by nested PCR. The positive brain samples were bioassayed in Webster Swiss mice. The serum samples of mice were examined for T. gondii antibodies by IFAT at 6 weeks post inoculation, and T. gondii cysts were searched in brain tissue samples of seropositive mice. The positive samples were genotyped by using a PCR-RLFP method. Subsequently, GRA6 sequences of isolates were analyzed using a phylogenetic method. The results revealed that T. gondii DNA was detected in 54% (20/37, 95% CI 38.4-69.0%) brain samples of ovine aborted fetuses. In bioassay of mice, only 2 samples were virulent and the mice were killed at 30 days post inoculation, while the others were non-virulent to mice. The size of cysts ranged 7-22 µm. Complete genotyping data for GRA6 locus were observed in 5 of the 20 samples. PCR-RLFP results and phylogenetic analysis revealed that all of the isolated samples were closely related to type I. For the first time, we could genotype and report T. gondii isolates from ovine aborted fetuses in Khorasan Razavi Province, Iran. The results indicate that the T. gondii isolates are genetically related to type I, although most of them were non-virulent for mice.
Aborted Fetus/*parasitology ; Animals ; Brain/parasitology ; Genotype ; Iran ; Mice ; Phylogeny ; Polymerase Chain Reaction ; Polymorphism, Restriction Fragment Length ; Sheep ; Sheep Diseases/*parasitology ; Toxoplasma/classification/*genetics/*isolation & purification/pathogenicity ; Toxoplasmosis, Animal/*parasitology

Toxoplasma gondii is a protozoan parasite with a broad range of intermediate hosts. Chickens as important food-producing animals can also serve as intermediate hosts. To date, experimental studies on the pathogenicity of T. gondii in broiler chickens were rarely reported. The objective of the present study was to compare the pathogenicity of 5 different T. gondii strains (RH, CN, JS, CAT2, and CAT3) from various host species origin in 10-day-old chickens. Each group of chickens was infected intraperitoneally with 5 x 10(8), 1 x 10(8), 1 x 10(7), and 1 x 10(6) tachyzoites of the 5 strains, respectively. The negative control group was mockly inoculated with PBS alone. After infection, clinical symptoms and rectal temperatures of all the chickens were checked daily. Dead chickens during acute phage of the infection were checked for T. gondii tachyzoites by microscope, while living cases were checked for T. gondii infection at day 53 post-inoculation (PI) by PCR method. Histopathological sections were used to observe the pathological changes in the dead chickens and the living animals at day 53 PI. No significant differences were found in survival periods, histopathological findings, and clinical symptoms among the chickens infected with the RH, CN, CAT2, and CAT3 strains. Histopathological findings and clinical symptoms of the JS (chicken origin) group were similar to the others. However, average survival times of infected chickens of the JS group inoculated with 5 x 10(8) and 1 x 10(8) tachyzoites were 30.0 and 188.4 hr, respectively, significantly shorter than those of the other 4 mammalian isolates. Chickens exposed to 10(8) of T. gondii tachyzoites and higher showed acute signs of toxoplasmosis, and the lesions were relatively more severe than those exposed to lower doses. The results indicated that the pathogenicity of JS strain was comparatively stronger to the chicken, and the pathogenicity was dose-dependent.
Animals ; Antibodies, Protozoan/blood ; Cat Diseases/parasitology ; Cats ; Chickens ; Poultry Diseases/blood/mortality/*parasitology/pathology ; Swine ; Swine Diseases/parasitology ; Toxoplasma/genetics/growth & development/*pathogenicity/physiology ; Toxoplasmosis, Animal/blood/mortality/*parasitology/pathology ; Virulence

The prevalence and genotype of Toxoplasma gondii infection in dogs in Henan Province, Central China was investigated. A total of 125 blood samples were collected from pet dogs during April to June 2013, and all samples were examined by indirect hemagglutination antibody test (IHA) and nested PCR. The overall T. gondii prevalence in pet dogs was 24.0% (30/125), with 20.8% (26/125) in IHA and 10.4% (13/125) in PCR, respectively. No statistical associations were found between animal gender and age and the prevalence of T. gondii infection. Thirteen positive DNA samples were genotyped using 11 PCR-RFLP markers, including SAG1, (3'+5') SAG2, alt.SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico. Of these, only 2 samples were genotyped with complete data for all loci, and a novel genotype (type III at SAG3 and GRA6 loci, and type I at other loci) was identified. This is the first report of genetic characterization of T. gondii infection in dogs in China.
Animals ; China/epidemiology ; Dog Diseases/*epidemiology/*parasitology ; Dogs ; Genotype ; Hemagglutination Tests ; Pets ; Polymerase Chain Reaction ; Polymorphism, Restriction Fragment Length ; Prevalence ; Toxoplasma/*classification/genetics/*isolation & purification ; Toxoplasmosis, Animal/*epidemiology/*parasitology

The prevalence and genotype of Toxoplasma gondii infection in dogs in Henan Province, Central China was investigated. A total of 125 blood samples were collected from pet dogs during April to June 2013, and all samples were examined by indirect hemagglutination antibody test (IHA) and nested PCR. The overall T. gondii prevalence in pet dogs was 24.0% (30/125), with 20.8% (26/125) in IHA and 10.4% (13/125) in PCR, respectively. No statistical associations were found between animal gender and age and the prevalence of T. gondii infection. Thirteen positive DNA samples were genotyped using 11 PCR-RFLP markers, including SAG1, (3'+5') SAG2, alt.SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico. Of these, only 2 samples were genotyped with complete data for all loci, and a novel genotype (type III at SAG3 and GRA6 loci, and type I at other loci) was identified. This is the first report of genetic characterization of T. gondii infection in dogs in China.
Animals ; China/epidemiology ; Dog Diseases/*epidemiology/*parasitology ; Dogs ; Genotype ; Hemagglutination Tests ; Pets ; Polymerase Chain Reaction ; Polymorphism, Restriction Fragment Length ; Prevalence ; Toxoplasma/*classification/genetics/*isolation & purification ; Toxoplasmosis, Animal/*epidemiology/*parasitology

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

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

The increasing prevalence of Toxoplasma gondii infection in the human population in the Republic of Korea (= Korea) is due to various reasons such as an increase in meat consumption. However, the importance of cats in transmitting T. gondii infection through oocysts to humans has seldom been assessed. A total of 300 fecal samples of stray cats captured around Seoul from June to August 2013 were examined for T. gondii B1 gene (indicating the presence of oocysts) using nested-PCR. Fourteen (4.7%) of 300 cats examined were positive for B1 gene. Female cats (7.5%) showed a higher prevalence than male cats (1.4%). Cats younger than 3 months (5.5%) showed a higher prevalence than cats (1.5%) older than 3 months. For laboratory passage of the positive samples, the fecal suspension (0.2 ml) of B1 gene positive cats was orally inoculated into experimental mice. Brain tissues of the mice were obtained after 40 days and examined for the presence of tissue cysts. Two isolates were successfully passaged (designated KNIH-1 and KNIH-2) and were molecularly analyzed using the SAG5D and SAG5E gene sequences. The SAG5D and SAG5E gene sequences showed high homologies with the ME49 strain (less virulent strain). The results indicated the importance of stray cats in transmitting T. gondii to humans in Korea, as revealed by detection of B1 gene in fecal samples. T. gondii isolates from cats were successfully passaged in the laboratory for the first time in Korea.
Animals ; Cat Diseases/diagnosis/epidemiology/*parasitology ; Cats ; Feces/*parasitology ; Female ; Genotype ; Humans ; Male ; Mice ; Protozoan Proteins/genetics ; Seoul/epidemiology ; Toxoplasma/genetics/*isolation & purification ; Toxoplasmosis/epidemiology/parasitology/transmission ; Toxoplasmosis, Animal/diagnosis/epidemiology/*parasitology