Toxoplasma gondii(T.gondii or Tg),is an obligatory intracellular parasite with humans as its intermediate hosts.In recent years,significant correlations between T.gondii infection and schizophrenia have been reported,...Toxoplasma gondii(T.gondii or Tg),is an obligatory intracellular parasite with humans as its intermediate hosts.In recent years,significant correlations between T.gondii infection and schizophrenia have been reported,including the possible mediating mechanisms.Currently,mechanisms and hypotheses focus on central neurotransmitters,immunity,neuroinflammation,and epigenetics;however,the exact underlying mechanisms remain unclear.In this article,we review the studies related to T.gondii infection and schizophrenia,particularly the latest research progress.Research on dopamine(DA)and other neurotransmitters,the blood-brain barrier,inflammatory factors,disease heterogeneity,and other confounders is also discussed.In addition,we also summarized the results of some new epidemiological investigations.展开更多
The aim of the study was to estimate the prevalence of antibodies to Toxoplasma gondii (T. gondii) and Neospora caninum (N. caninum) in pigs in Grenada, West Indies. T. gondii is a serious zoonosis affecting the unbor...The aim of the study was to estimate the prevalence of antibodies to Toxoplasma gondii (T. gondii) and Neospora caninum (N. caninum) in pigs in Grenada, West Indies. T. gondii is a serious zoonosis affecting the unborn fetus and immunocompromized individuals. N. caninum is a similar coccidian parasite, which is not zoonotic, but is the cause of abortion and neonatal mortality in livestock similar to T. gondii. An earlier study conducted in Grenada and using a modified agglutination test (MAT) revealed seropositivity to T. gondii in pigs. No information is available on N. caninum infection of pigs in the Caribbean islands including Grenada. Serum samples from 185 pigs in Grenada, West Indies were tested for antibodies to T. gondii and N. caninum using an indirect enzyme linked immunosorbent assay (ELISA). Antibodies to T. gondii were found in 24.3% of pigs (95% confidence interval (CI): 18.12% to 30.48%) as all the tested pigs were negative for antibodies to N. caninum. Although, seroprevalence for T. gondii was higher in females (25.75%) than in males (20.70%), this result was statistically insignificant (p = 0.57). The results were similar to a previous study in Grenada confirming the continuity of infection in pigs. Human Toxoplasmosis is transmitted mainly through ingestion of tissue cysts in contaminated raw or undercooked meat or sporulated oocysts in soil, water or vegetables. Education of farmers and the Grenadian community on epidemiology of these parasites is warranted to prevent infection in pigs and in humans. This is the first report on the seroprevalence of N. caninum in pigs in the Caribbean region.展开更多
The objective of the present investigation was to estimate the prevalence of Toxoplasma gondii infection and co-infection with porcine reproductive and respiratory syndrome virus(PRRSV), classical swine fever virus(CS...The objective of the present investigation was to estimate the prevalence of Toxoplasma gondii infection and co-infection with porcine reproductive and respiratory syndrome virus(PRRSV), classical swine fever virus(CSFV) and porcine circovirus type 2(PCV-2) in pigs in China. A total of 372 tissues or serum samples collected from pigs distributed in 9 provinces/municipalities of China during the period from February 2011 to November 2012 were assayed for T. gondii antigens and antibodies using enzyme linked immunosorbent assay(ELISA) technique, while the PCR was designed for the detection of the PRRSV, CSFV and PCV-2, respectively. The total positive rate of T. gondii, PRSSV, CSFV and PCV-2 was 9.14%(34/372), 50.00%(186/372), 37.10%(138/372) and 3.23%(12/372), respectively. Among the 34 T. gondii positive samples, 26 samples were simultaneously infected with T. gondii and viruses, while the remaining eight samples were infected with T. gondii alone. In addition, the co-infection rate of T. gondii with PRSSV, T. gondii with PRSSV and CSFV, T. gondii with PRSSV and PCV-2, T. gondii with CSFV and PCV-2, T. gondii with PRSSV, CSFV and PCV-2 was 1.61%(6/372), 4.03%(15/372), 0.27%(1/372), 0.27%(1/372) and 0.81%(3/372), respectively. The results of the present survey revealed that PRRSV and CSFV were the common pathogens co-existing with porcine toxoplasmosis in China, and both of them could increase the chances of T. gondii infection in pig. This is the first report of T. gondii co-infections with viruses in pigs. It is very important to understand the interactions of parasite and virus, and can be used as reference data for the control and prevention of co-infections of T. gondii and viruses in pigs.展开更多
Objective The protozoan Toxoplasma gondii expresses large amounts of a 37 kDa Type 2C serine-threonine phosphatase,the so-called TgPP2 C which has been suggested to contribute to parasite growth regulation.Ectopic exp...Objective The protozoan Toxoplasma gondii expresses large amounts of a 37 kDa Type 2C serine-threonine phosphatase,the so-called TgPP2 C which has been suggested to contribute to parasite growth regulation.Ectopic expression in mammalian cells also indicated that the enzyme could regulate growth and survival.In this study,we aimed to investigate the interaction of TgPP2 C with human SSRP1(structure-specific recognition protein 1) and the effects of TgPP2 C on cell viability.Methods The yeast two hybrid system,His-tag pull-down and co-immunoprecipitation assays were used to confirm the interaction of TgPP2 C with SSRP1 and determine the binding domain on SSRP1.The evaluation of cell apoptosis was performed using cleaved caspase-3 antibody and Annexin-V/PI kit combined with flow cytometry.Results We identified human SSRP1 as an interacting partner of TgPP2 C.The C-terminal region of SSRP1 including the amino acids 471 to 538 was specifically mapped as the region responsible for interaction with TgPP2 C.The overexpression of TgPP2 C down-regulated cell apoptosis and negatively regulated apoptosis induced by DRB,casein kinase II(CKII) inhibitor,through enhanced interaction with SSRP1.Conclusion TgPP2 C may be a parasitic factor capable of promoting cell survival through interaction with the host protein SSRP1,thereby creating a favorable environment for parasite growth.展开更多
Objective:To compare analytical sensitivity and specificity of a newly described DNA amplification technique.LAMP and nested PCR assay targeting the RE and Bl genes for the detection of Toxoplasma gondii(T.gondii) DNA...Objective:To compare analytical sensitivity and specificity of a newly described DNA amplification technique.LAMP and nested PCR assay targeting the RE and Bl genes for the detection of Toxoplasma gondii(T.gondii) DNA.Methods:The analytical sensitivity of LAMP and ncstcd-PCR was obtained against 10-fold serial dilutions of T.gondii DNA ranging from 1 ng to 0.01 fg.DNA samples of other parasites and human chromosomal DNA were used to determine the specificity of molecular assays.Results:After testing LAMP and nesled-PCR in duplicate,the detection limit of RE-LAMP.B1-LAMP,RE-nested PCR and B1-nested PCR assays was one fg.100 fg,1 pg and 10 pg of T.gondii DNA respectively.All the LAMP assays and nested PCRs were 100% specific.The RE-LAMP assay revealed the most sensitivity for the detection of T.gondii DNA.Conclusions:The obtained results demonstrate that the LAMP technique has a greater sensitivity for detection of T.gondii.Furthermore,these findings indicate that primers based on the RE are more suitable than those based on the B1 gene.However,the B1-LAMP assay has potential as a diagnostic tool for detection of T.gondii.展开更多
Objective:To evaluate parasite distribution and tissue tropism of Toxoplasma gondii tachyzoites in experimentally infected mice using real time QPCR.Methods:In this survey 16 Balb/c mice were inoculated with 1×10...Objective:To evaluate parasite distribution and tissue tropism of Toxoplasma gondii tachyzoites in experimentally infected mice using real time QPCR.Methods:In this survey 16 Balb/c mice were inoculated with 1×10~4 alive tachyzoites of Toxoplasma gondii RH strain.After 1,2,3 days post infection and the last day(before death),different tissues of mice including blood,brain,eye,liver,spleen,kidney,heart and muscle were harvested.Following tissues DNA extraction,the parasite burden was quantified using real time QPCR targeting the B1 gene(451 bp).Results:It showed that Toxoplasma after intraperitoneal injection was able to movement to various tissues in24 hours.Parasite burden was high in all tissues but the most number of parasites were observed in kidney,heart and liver,respectively.Conclusions:These data provide significant baseline information about Toxoplasma pathogenesis,vaccine monitoring and drug efficiency.展开更多
Objective: To identify serodiagnosis and quantification of Toxoplasma gondii(T. gondii) infection among pregnant women in Salmas, northwest of Iran. Methods: In this crosssectional study, 276 blood samples were collec...Objective: To identify serodiagnosis and quantification of Toxoplasma gondii(T. gondii) infection among pregnant women in Salmas, northwest of Iran. Methods: In this crosssectional study, 276 blood samples were collected from pregnant women referred to the health care centers in Salmas city. The demographic variables were also recorded. Titers of antiToxoplasma IgM and IgG antibodies(Ab) were determined using the chemiluminescence immunoassay. Quantitative real-time PCR targeting the T. gondii repeated element gene was also performed on the blood sample. Results: Out of all, 19.92%(55/276) and 2.17%(6/276) patients were seropositive for anti-Toxoplasma IgG and IgM Ab, respectively. Moreover, the presence of T. gondii DNA was observed in 12.31%(34/276) blood samples. A significant relationship was observed between the IgG Ab seropositivity and contact with the cat as a risk factor(P=0.022). Conclusions: The seroprevalence rate of T. gondii infection in pregnant women is relatively low. Consequently, the seronegative pregnant women are at risk, and a considerable rate of positive blood samples for the presence of parasite's DNA should not be ignored. Besides, quantitative real-time PCR could be considered as an accurate method for diagnosis of acute toxoplasmosis especially when the precise results are of the most importance in pregnancy. Limiting contact with cats is also suggested for pregnant women.展开更多
AIM: To analyze the biological role of the surface antigen of Toxoplasma gondii(Tgondii) in development of vaccine. METHODS: The surface antigen of Tgondii (SAG1) was expressed in vitro. The immune response of t...AIM: To analyze the biological role of the surface antigen of Toxoplasma gondii(Tgondii) in development of vaccine. METHODS: The surface antigen of Tgondii (SAG1) was expressed in vitro. The immune response of the host to the antigen was investigated by detection of specific antibody reaction to SAG1 and production of cytokines. Mice were immunized with recombinant SAG1 and challenged with lethal strain of Tgondii RH. The monoclonal antibody to r-SAG1 was prepared and used to study the effects of SAG1 on Tgondii tachyzoites under electromicroscope. RESULTS: The mice immunized with recombinant SAG1 delayed death for 60 h compared to the control group. The recombinant SAG1 induced specific high titer of IgG and IgM antibodies as well as IFN-y, IL-2 and IL-4 cytokines in mice. In contrast, IL-12, IL-6 and TNF-α were undetectable. When T gondii tachyzoites were treated with the monoclonal antibody to r-SAG1, the parasites were gathered together, destroyed, deformed, swollen, and holes and gaps formed on the surface. CONCLUSION: SAG1 may be an excellent vaccine candidate against T gondii. The immune protection induced by SAG1 against Tgondii may be regulated by both hormone- and cell-mediated immune response.展开更多
One strain of Toxoplasma gondii was successfully isolated from chickens in China by bioassay in mice. Antibodies and circulating antigens of T. gondii were assayed by the ELISA kits in 100 free range chickens from a r...One strain of Toxoplasma gondii was successfully isolated from chickens in China by bioassay in mice. Antibodies and circulating antigens of T. gondii were assayed by the ELISA kits in 100 free range chickens from a rural area surrounding Funing, China. Fifty-three chickens were antibody-positive and 21 chickens were antigen positive. Hearts, brains, spleens, lungs, livers, and kidneys of 21 antibody or antigen-positive chickens were bioassayed in mice. One strain of T. gondii was isolated from 1 of 21 (4.76%) chickens. The isolated T. gondii killed all of the inoculated mice. Genotyping of this isolate using polymorphisms at the loci 5′-SAG2, 3′-SAG2, SAG3, cB21-4, L358, BTUB, and GRA6 revealed that it was Type I. These indicated that it was virulent for mice. This is the first report of isolation of T. gondii from chickens in China.展开更多
Background:Few investigations of genotype II of Toxoplasma gondii,the most preva-lent form of the Toxoplasma parasite in humans,have been carried out on due to the rapid conversion of tachyzoites to bradyzoites in its...Background:Few investigations of genotype II of Toxoplasma gondii,the most preva-lent form of the Toxoplasma parasite in humans,have been carried out on due to the rapid conversion of tachyzoites to bradyzoites in its life cycle.The current study aimed to create animal and in vitro models for production of the tachyzoites of the Prugniaud(PRU)genotype II strain.Methods:To develop an immunocompromised model and obtain tachyzoites of the PRU strain,BALB/c mice were orally treated with dexamethasone(10 mg/kg),cyclo-phosphamide(36 mg/kg),and cyclosporine(18 mg/kg)from 5 days prior to inocula-tion.Then,10-15 tissue cysts of PRU strain were inoculated intraperitoneally into the mice.The tachyzoites obtained from mice were then cultivated in a HeLa cell culture.The resulting yield of tachyzoites was cryopreserved in 92%fetal calf serum,8%dimethyl sulfoxide.The infectivity of these tachyzoites was evaluated using in vivo and in vitro examinations.Results:Numerous tachyzoites were observed in the peritoneal fluid of the immuno-suppressed mice within 10-15 days after inoculation,and many tachyzoites were har-vested from the HeLa cell culture.Trypan Blue staining showed 80%viability of the tachyzoites recovered from cryopreservation and this was confirmed by HeLa cell culture.In addition,mice infected intraperitoneally with the recovered tachyzoites presented with cysts in the brain after 2 months.Conclusion:We have developed an animal model for mass production of T.gondii tachyzoites of the PRU strain.This method can provide fresh viable tachyzoites of Toxoplasma gondii for use as and when required in future investigations.展开更多
Objective:To determine the seroprevalence of Toxoplasma gondii(T.gondii) infection in dogs and cats in Zhenjiang City,Jiangsu Province.Eastern China,and to evaluate the main associated risk factors relating to exposur...Objective:To determine the seroprevalence of Toxoplasma gondii(T.gondii) infection in dogs and cats in Zhenjiang City,Jiangsu Province.Eastern China,and to evaluate the main associated risk factors relating to exposure to 71 gondii in this region.Methods:Sera from 160 clogs and 116 cats from Zhenjiang City were tested for anti-T.gondii antibodies using EUSA.The seropositivity by area of activity,sex and age was analyzed.Results:Overall.21 dogs(13.l%) and 24 cats(20.7%) had antibodies to T.gondii.The infection rate in stray dogs(38.7%) and cats(28.6%! was significantly higher(P<0.05) than in household dogs(6.9%) and cats(18.2%).The seroprevalence in male clogs(14.8%) and cats(21.05%) were slighlly higher than their female counterparts(11.4%in dogs and 20.0%in cats),but were not significantly differenent(P>0.05).A high proportion of dogs at 3 to 6 years of age were positive to T.gondii(20.0%)while cats with relatively high seropositivity rates were at 0 to 1 year of age(33.3%).Conclusions:The prevalence of T.gondii infection in dogs and cats in Zhenjiang City was high,which is probably the main source of T.gondii infection in this area.展开更多
Objective: To know the difference between chemerin and adipocyte fatty acid-binding protein(AFABP) levels in obese individuals with positive Toxoplasma gondii(T. gondii)immunoglobulin G(IgG) compared with negative T. ...Objective: To know the difference between chemerin and adipocyte fatty acid-binding protein(AFABP) levels in obese individuals with positive Toxoplasma gondii(T. gondii)immunoglobulin G(IgG) compared with negative T. gondii IgG.Methods: This study is a cross-sectional study by using consecutive sampling methods conducted from January to April 2013. The subjects were 57 obese individuals who were divided into obese group of positive and negative T. gondii IgG. The level of chemerin,AFABP and T. gondii IgG was done by ELISA. The data were analyzed by independent t test.Results: The results showed that the level of chemerin of positive T. gondii IgG group was significantly higher than the negative T. gondii IgG group [(70.0 ± 16.5) vs.(64.4 ± 16.1) pg/mL; P = 0.003], but there was not significant AFABP difference between seropositive and negative IgG groups [(83.6 ± 41.9) vs.(74.2 ± 36.7) pg/mL; P = 0.598].Conclusions: It can be concluded that the level of chemerin of seropositive T. gondii IgG was higher than that in the negative T. gondii IgG group.展开更多
Objective:To discuss the influence of tachyzoite of Toxoplasma gondii(T.gondii) RH strain on proliferation and apoptosis of hepatoma carcinoma(HCC) H7402 cell.Methods:The HCC H7402 cell in logarithmic phase and ta...Objective:To discuss the influence of tachyzoite of Toxoplasma gondii(T.gondii) RH strain on proliferation and apoptosis of hepatoma carcinoma(HCC) H7402 cell.Methods:The HCC H7402 cell in logarithmic phase and tachyzoite of T.gondii RH strain in different concentrations(1×107/mL,2×107/mL.4×107/mL,8×107mL and 16×107/mL) were co-cultured.CCK-8was utilized to determine the inhibition rate of T.gondii tachyzoite on H7402 cell growth.Flow cytometry was used to detect the change of cell cycle.RT-PCR method was used to detect the expression of cyclinB1 and cdc2-two genes related to cell cycle.Western blot method was used to detect the expression of apoptosis-related proteins Caspase-3 and Bcl-2.Results:The tachyzoite of T.gondii RH strain can inhibit the proliferation of HCC H7402 cells.The inhibition rate of tumor cell growth increased with the increase of concentration of T.gondii tachyzoite.With the increase of concentration of T.gondii tachyzoite,the proportion of G0/G1 phase of H7402 cell increased,the proportion of S phase decreased,and PI value decreased accordingly.The expression of cyclinB1 and cdc2 genes decreased with the increase of the concentration of T.gondii tachyzoite.With the increase of the concentration of tachyzoite of T.gondii RH strain,the expression quantity of Caspase-3 in H7402 cell increased,but the expression quantity of Bcl-2protein decreased.Conclusions:T.gondii can inhibit the in vitro proliferation of HCC H7402 cell,and induce its apoptosis.This effect shows a trend of concentration-dependent increase.Moreover,it is related to the down-regulation of cyclinB1 and cdc2(cell cycle-related genes),the increase of apoptosis-related protein Caspase-3.and the decreasc of Bcl-2 expression.展开更多
Objective: To produce the major surface antigen (p30) of Toxoplasma gondii from the Baculovirus Expression System. Methods: The p30 coding sequence was cloned into a transfer vector, then the recombinant baculovirus c...Objective: To produce the major surface antigen (p30) of Toxoplasma gondii from the Baculovirus Expression System. Methods: The p30 coding sequence was cloned into a transfer vector, then the recombinant baculovirus containing p30 gene was cloned and purified by the co-transfection and plaque assay. The expression and immunoactivity of the recombinant p30 were analyzed by SDS-PAGE and Western blot. The immune responses in mice for being immunized with recombinant p30 were tested. Results: About 750μg of purified (95% purity) p30 was obtained from a culture of 108 in- sect Sf21 cells. Mice in injected with the recombinant protein produced specific humoral and cellular immune responses. Immunization with p30 also prolonged the period of mice survival infected by Toxoplasma gondii. Conclusion: It is indicated that the recombinant p30 from baculovirus expression system can stimulate mice to produce effective protection from Toxo- plasma gondii infection.展开更多
Nucleoside triphosphate hydrolase (NTPase) is a multifunctional enzymatic family widely existing in vivo. They can hydrolyze NTP to NMP or dNTP to dNMP to produce energy. In this article, the structure of Toxoplasma...Nucleoside triphosphate hydrolase (NTPase) is a multifunctional enzymatic family widely existing in vivo. They can hydrolyze NTP to NMP or dNTP to dNMP to produce energy. In this article, the structure of Toxoplasma gondii NTPase is analyzed. The research progress in NT- Pase of Toxoplasrna gondii, Trypanosoma cruzi, Sarcocystis neurona and Neospora caninum was briefly reviewed.展开更多
According to the published gene sequence of the major surface antigen (P30) of Toxoplasma gondii, a pair of primers were designed and synthesized. Using polymerase chain reaction (PCR), the coding sequences of P30 gen...According to the published gene sequence of the major surface antigen (P30) of Toxoplasma gondii, a pair of primers were designed and synthesized. Using polymerase chain reaction (PCR), the coding sequences of P30 gene were amplified from a Chinese strain of T. gondii, The amplified gene fragment and plasmid pB220 were digested with EcoRI and BamHI and then ligated. The inserted gene fragment was sequenced by the chain termination method, the reading reveals that nucleotide sequence determined was the same as the P30 sequecne of RH strain pubilished by Burg (1988), except that one base was changed. The recombinant plasmid containing P30 gene was transformed to E. coli DH5α.After temperature inducing culture, the total cellular proteins were analysed by SDS-PAGE and Western blot. The results show that the p30 gene cloned into the plasmid could express in E. coli, and the expression product had immunogenicity.展开更多
[Objective] To develop a new method for serodiagnosis of swine toxoplasmosis. [Method] With the purified recombinant microneme protein 3 (rMIC3) as coating antigens, an indirect ELISA was developed for detection of ...[Objective] To develop a new method for serodiagnosis of swine toxoplasmosis. [Method] With the purified recombinant microneme protein 3 (rMIC3) as coating antigens, an indirect ELISA was developed for detection of antibodies against Toxoplasma gondii. [ Result] The optimal working concentration of rMIC3 was 3. 40 ug/ml, and the optimal degree of dilution of sera was 1:160. Cross-reaction was not observed between the Toxoplasma gondii-positive sera and the positive sera against classical swine fever virus or some other pathogens. The developed ELISA had 92.56% coincidence rate with latex agglutination test. [ Conclusion] The developed ELISA is sensitive, rapid, specific and reproducible, and thus it can be applied in serodiagnosis and seroprevalence investigation of swine toxoplasmosis.展开更多
Objective: To report two recent cases of pituitary adenoma associated with Toxoplasma gondii (T.Gondii) infection.Methods: Histological changes were observed in H & E and PAS staining sections microscopically.Immu...Objective: To report two recent cases of pituitary adenoma associated with Toxoplasma gondii (T.Gondii) infection.Methods: Histological changes were observed in H & E and PAS staining sections microscopically.Immunohistochemistry was performed to classify the pituitary tumors and to confirm the diagnosis of T.gondii.Results: The cases were 43- and 19-year-old females, in which the latter one was a recurring case, and radiology examination showed that tumors existed in sellar region.Microscopically, the tumors consisted of small homogenous polygonal or round cells with abundant eosinophilic granular cytoplasm.Immunohistochemistry revealed they were prolactin-producing adenomas.Interestingly, we found toxoplasma infection in the tumor tissues, being confirmed by T.gondii sepicific antibody immunohistochemistry.Conclusion: The association of pituitary adenoma with toxoplasma raises the possibility that T.gondii may be involved in the development of certain cases of pituitary adenoma.展开更多
Several researchers have investigated the association of numerous opportunistic pathogens with HIV, little is documented on its association with T. gondii in our environment. We investigated the prevalence of T. gondi...Several researchers have investigated the association of numerous opportunistic pathogens with HIV, little is documented on its association with T. gondii in our environment. We investigated the prevalence of T. gondii immunoglobulins G and M (IgG and IgM) in HIV positive individuals in relation to their cluster of differentiation 4 (CD4) cells count. IgG, IgM and CD4 were assayed using enzyme immunoassay (EIA) and flowcytometry respectively. 341 HIV positive individuals were studied in the present research, 30 (8.7%) of them had T. gondii IgG and IgM, 297 subjects had CD4 cells count a range of 200-400 cells/μL, 27 (9.7%) and 2 (0.6%) of which had T. gondii IgG and IgM respectively. Of the 44 HIV positive subjects with CD4 〉 400 cells/μL, one (2.2%) was positive for T. gondii IgG. In the control group, all the 177 had CD4 〉 400 cells/μL of which, one (0.5%) had T. gondii IgG. The prevalence of T. gondii infection was significantly higher in HIV positive individuals than in controls (P 〈 0.05). Male subjects in the age bracket 18-30 years had significantly higher prevalence when compared to other groups (P 〈 0.05). Although the present findings revealed a low prevalence of T. gondii antibodies in HIV infection, this suggests that a differential toxoplasmosis diagnosis is also necessary in cases of encephalitis in HIV infection.展开更多
基金supported in part by grants from the National Natural Sciences Foundation of China[grant nos.82072306 and 32370197 to XW]the National Key Research and Development Program of China[no.2022YFC2304000].
文摘Toxoplasma gondii(T.gondii or Tg),is an obligatory intracellular parasite with humans as its intermediate hosts.In recent years,significant correlations between T.gondii infection and schizophrenia have been reported,including the possible mediating mechanisms.Currently,mechanisms and hypotheses focus on central neurotransmitters,immunity,neuroinflammation,and epigenetics;however,the exact underlying mechanisms remain unclear.In this article,we review the studies related to T.gondii infection and schizophrenia,particularly the latest research progress.Research on dopamine(DA)and other neurotransmitters,the blood-brain barrier,inflammatory factors,disease heterogeneity,and other confounders is also discussed.In addition,we also summarized the results of some new epidemiological investigations.
文摘The aim of the study was to estimate the prevalence of antibodies to Toxoplasma gondii (T. gondii) and Neospora caninum (N. caninum) in pigs in Grenada, West Indies. T. gondii is a serious zoonosis affecting the unborn fetus and immunocompromized individuals. N. caninum is a similar coccidian parasite, which is not zoonotic, but is the cause of abortion and neonatal mortality in livestock similar to T. gondii. An earlier study conducted in Grenada and using a modified agglutination test (MAT) revealed seropositivity to T. gondii in pigs. No information is available on N. caninum infection of pigs in the Caribbean islands including Grenada. Serum samples from 185 pigs in Grenada, West Indies were tested for antibodies to T. gondii and N. caninum using an indirect enzyme linked immunosorbent assay (ELISA). Antibodies to T. gondii were found in 24.3% of pigs (95% confidence interval (CI): 18.12% to 30.48%) as all the tested pigs were negative for antibodies to N. caninum. Although, seroprevalence for T. gondii was higher in females (25.75%) than in males (20.70%), this result was statistically insignificant (p = 0.57). The results were similar to a previous study in Grenada confirming the continuity of infection in pigs. Human Toxoplasmosis is transmitted mainly through ingestion of tissue cysts in contaminated raw or undercooked meat or sporulated oocysts in soil, water or vegetables. Education of farmers and the Grenadian community on epidemiology of these parasites is warranted to prevent infection in pigs and in humans. This is the first report on the seroprevalence of N. caninum in pigs in the Caribbean region.
基金supported by the Special Fund for Public Welfare Industry of Ministry of Agriculture of China (20090303604)the Priority Academic Program Development of Jiangsu Higher Education Institutions, China (PAPD)
文摘The objective of the present investigation was to estimate the prevalence of Toxoplasma gondii infection and co-infection with porcine reproductive and respiratory syndrome virus(PRRSV), classical swine fever virus(CSFV) and porcine circovirus type 2(PCV-2) in pigs in China. A total of 372 tissues or serum samples collected from pigs distributed in 9 provinces/municipalities of China during the period from February 2011 to November 2012 were assayed for T. gondii antigens and antibodies using enzyme linked immunosorbent assay(ELISA) technique, while the PCR was designed for the detection of the PRRSV, CSFV and PCV-2, respectively. The total positive rate of T. gondii, PRSSV, CSFV and PCV-2 was 9.14%(34/372), 50.00%(186/372), 37.10%(138/372) and 3.23%(12/372), respectively. Among the 34 T. gondii positive samples, 26 samples were simultaneously infected with T. gondii and viruses, while the remaining eight samples were infected with T. gondii alone. In addition, the co-infection rate of T. gondii with PRSSV, T. gondii with PRSSV and CSFV, T. gondii with PRSSV and PCV-2, T. gondii with CSFV and PCV-2, T. gondii with PRSSV, CSFV and PCV-2 was 1.61%(6/372), 4.03%(15/372), 0.27%(1/372), 0.27%(1/372) and 0.81%(3/372), respectively. The results of the present survey revealed that PRRSV and CSFV were the common pathogens co-existing with porcine toxoplasmosis in China, and both of them could increase the chances of T. gondii infection in pig. This is the first report of T. gondii co-infections with viruses in pigs. It is very important to understand the interactions of parasite and virus, and can be used as reference data for the control and prevention of co-infections of T. gondii and viruses in pigs.
基金supported by the Natural Science Foundation of Guangdong Province(Grant No.9151065004000005)National Program on Key Basic Research Project(973 Program)(Grant No.2011CB910700)+6 种基金High-Level Talents Project of the Universities of Guangdong(No.[2011]431)National Natural Science Foundation of China(Grant No.3100062881071790)Natural Science Foundation of Guangdong Province(Grant No.S2013030013315)Fundamental Research Funds for the Central Universities(Grant No.216114302161010121609317)
文摘Objective The protozoan Toxoplasma gondii expresses large amounts of a 37 kDa Type 2C serine-threonine phosphatase,the so-called TgPP2 C which has been suggested to contribute to parasite growth regulation.Ectopic expression in mammalian cells also indicated that the enzyme could regulate growth and survival.In this study,we aimed to investigate the interaction of TgPP2 C with human SSRP1(structure-specific recognition protein 1) and the effects of TgPP2 C on cell viability.Methods The yeast two hybrid system,His-tag pull-down and co-immunoprecipitation assays were used to confirm the interaction of TgPP2 C with SSRP1 and determine the binding domain on SSRP1.The evaluation of cell apoptosis was performed using cleaved caspase-3 antibody and Annexin-V/PI kit combined with flow cytometry.Results We identified human SSRP1 as an interacting partner of TgPP2 C.The C-terminal region of SSRP1 including the amino acids 471 to 538 was specifically mapped as the region responsible for interaction with TgPP2 C.The overexpression of TgPP2 C down-regulated cell apoptosis and negatively regulated apoptosis induced by DRB,casein kinase II(CKII) inhibitor,through enhanced interaction with SSRP1.Conclusion TgPP2 C may be a parasitic factor capable of promoting cell survival through interaction with the host protein SSRP1,thereby creating a favorable environment for parasite growth.
基金supported financially by grant of Lorestan University of Medical Sciences,Khorramabad,Iran
文摘Objective:To compare analytical sensitivity and specificity of a newly described DNA amplification technique.LAMP and nested PCR assay targeting the RE and Bl genes for the detection of Toxoplasma gondii(T.gondii) DNA.Methods:The analytical sensitivity of LAMP and ncstcd-PCR was obtained against 10-fold serial dilutions of T.gondii DNA ranging from 1 ng to 0.01 fg.DNA samples of other parasites and human chromosomal DNA were used to determine the specificity of molecular assays.Results:After testing LAMP and nesled-PCR in duplicate,the detection limit of RE-LAMP.B1-LAMP,RE-nested PCR and B1-nested PCR assays was one fg.100 fg,1 pg and 10 pg of T.gondii DNA respectively.All the LAMP assays and nested PCRs were 100% specific.The RE-LAMP assay revealed the most sensitivity for the detection of T.gondii DNA.Conclusions:The obtained results demonstrate that the LAMP technique has a greater sensitivity for detection of T.gondii.Furthermore,these findings indicate that primers based on the RE are more suitable than those based on the B1 gene.However,the B1-LAMP assay has potential as a diagnostic tool for detection of T.gondii.
基金prepared from Yousef Dadimoghaddam's MScthesis and supported by grant(no.90-31) from Deputy of Research,Mazandaran University of Medical Sciences.Sari,IranThe spousor or Junding organization had norole in the design or conduct of this research
文摘Objective:To evaluate parasite distribution and tissue tropism of Toxoplasma gondii tachyzoites in experimentally infected mice using real time QPCR.Methods:In this survey 16 Balb/c mice were inoculated with 1×10~4 alive tachyzoites of Toxoplasma gondii RH strain.After 1,2,3 days post infection and the last day(before death),different tissues of mice including blood,brain,eye,liver,spleen,kidney,heart and muscle were harvested.Following tissues DNA extraction,the parasite burden was quantified using real time QPCR targeting the B1 gene(451 bp).Results:It showed that Toxoplasma after intraperitoneal injection was able to movement to various tissues in24 hours.Parasite burden was high in all tissues but the most number of parasites were observed in kidney,heart and liver,respectively.Conclusions:These data provide significant baseline information about Toxoplasma pathogenesis,vaccine monitoring and drug efficiency.
基金supported by Infectious and Tropical Disease Research Center,Tabriz University of Medical Sciences,Tabriz,Iran(Grant No.94/2-5/17)
文摘Objective: To identify serodiagnosis and quantification of Toxoplasma gondii(T. gondii) infection among pregnant women in Salmas, northwest of Iran. Methods: In this crosssectional study, 276 blood samples were collected from pregnant women referred to the health care centers in Salmas city. The demographic variables were also recorded. Titers of antiToxoplasma IgM and IgG antibodies(Ab) were determined using the chemiluminescence immunoassay. Quantitative real-time PCR targeting the T. gondii repeated element gene was also performed on the blood sample. Results: Out of all, 19.92%(55/276) and 2.17%(6/276) patients were seropositive for anti-Toxoplasma IgG and IgM Ab, respectively. Moreover, the presence of T. gondii DNA was observed in 12.31%(34/276) blood samples. A significant relationship was observed between the IgG Ab seropositivity and contact with the cat as a risk factor(P=0.022). Conclusions: The seroprevalence rate of T. gondii infection in pregnant women is relatively low. Consequently, the seronegative pregnant women are at risk, and a considerable rate of positive blood samples for the presence of parasite's DNA should not be ignored. Besides, quantitative real-time PCR could be considered as an accurate method for diagnosis of acute toxoplasmosis especially when the precise results are of the most importance in pregnancy. Limiting contact with cats is also suggested for pregnant women.
基金Supported by China Ministry of Human Affairs and Department of Science and Technology of Shandong Province, No. 031050115
文摘AIM: To analyze the biological role of the surface antigen of Toxoplasma gondii(Tgondii) in development of vaccine. METHODS: The surface antigen of Tgondii (SAG1) was expressed in vitro. The immune response of the host to the antigen was investigated by detection of specific antibody reaction to SAG1 and production of cytokines. Mice were immunized with recombinant SAG1 and challenged with lethal strain of Tgondii RH. The monoclonal antibody to r-SAG1 was prepared and used to study the effects of SAG1 on Tgondii tachyzoites under electromicroscope. RESULTS: The mice immunized with recombinant SAG1 delayed death for 60 h compared to the control group. The recombinant SAG1 induced specific high titer of IgG and IgM antibodies as well as IFN-y, IL-2 and IL-4 cytokines in mice. In contrast, IL-12, IL-6 and TNF-α were undetectable. When T gondii tachyzoites were treated with the monoclonal antibody to r-SAG1, the parasites were gathered together, destroyed, deformed, swollen, and holes and gaps formed on the surface. CONCLUSION: SAG1 may be an excellent vaccine candidate against T gondii. The immune protection induced by SAG1 against Tgondii may be regulated by both hormone- and cell-mediated immune response.
基金supported by the Special Fund for Public Welfare Industry of Chinese Ministry of Agriculture(200903036-04)
文摘One strain of Toxoplasma gondii was successfully isolated from chickens in China by bioassay in mice. Antibodies and circulating antigens of T. gondii were assayed by the ELISA kits in 100 free range chickens from a rural area surrounding Funing, China. Fifty-three chickens were antibody-positive and 21 chickens were antigen positive. Hearts, brains, spleens, lungs, livers, and kidneys of 21 antibody or antigen-positive chickens were bioassayed in mice. One strain of T. gondii was isolated from 1 of 21 (4.76%) chickens. The isolated T. gondii killed all of the inoculated mice. Genotyping of this isolate using polymorphisms at the loci 5′-SAG2, 3′-SAG2, SAG3, cB21-4, L358, BTUB, and GRA6 revealed that it was Type I. These indicated that it was virulent for mice. This is the first report of isolation of T. gondii from chickens in China.
基金This research was funded by the project 97-01-01-18897 from Shiraz University of Medical Sciences,Shiraz,Iran.
文摘Background:Few investigations of genotype II of Toxoplasma gondii,the most preva-lent form of the Toxoplasma parasite in humans,have been carried out on due to the rapid conversion of tachyzoites to bradyzoites in its life cycle.The current study aimed to create animal and in vitro models for production of the tachyzoites of the Prugniaud(PRU)genotype II strain.Methods:To develop an immunocompromised model and obtain tachyzoites of the PRU strain,BALB/c mice were orally treated with dexamethasone(10 mg/kg),cyclo-phosphamide(36 mg/kg),and cyclosporine(18 mg/kg)from 5 days prior to inocula-tion.Then,10-15 tissue cysts of PRU strain were inoculated intraperitoneally into the mice.The tachyzoites obtained from mice were then cultivated in a HeLa cell culture.The resulting yield of tachyzoites was cryopreserved in 92%fetal calf serum,8%dimethyl sulfoxide.The infectivity of these tachyzoites was evaluated using in vivo and in vitro examinations.Results:Numerous tachyzoites were observed in the peritoneal fluid of the immuno-suppressed mice within 10-15 days after inoculation,and many tachyzoites were har-vested from the HeLa cell culture.Trypan Blue staining showed 80%viability of the tachyzoites recovered from cryopreservation and this was confirmed by HeLa cell culture.In addition,mice infected intraperitoneally with the recovered tachyzoites presented with cysts in the brain after 2 months.Conclusion:We have developed an animal model for mass production of T.gondii tachyzoites of the PRU strain.This method can provide fresh viable tachyzoites of Toxoplasma gondii for use as and when required in future investigations.
基金Supported by the Project of Access Engineers of Higher Vocational Institutions in Jiangsu Province(Project No.2013FG042)Jiangsu Polytechnic College of Agriculture and Forestry
文摘Objective:To determine the seroprevalence of Toxoplasma gondii(T.gondii) infection in dogs and cats in Zhenjiang City,Jiangsu Province.Eastern China,and to evaluate the main associated risk factors relating to exposure to 71 gondii in this region.Methods:Sera from 160 clogs and 116 cats from Zhenjiang City were tested for anti-T.gondii antibodies using EUSA.The seropositivity by area of activity,sex and age was analyzed.Results:Overall.21 dogs(13.l%) and 24 cats(20.7%) had antibodies to T.gondii.The infection rate in stray dogs(38.7%) and cats(28.6%! was significantly higher(P<0.05) than in household dogs(6.9%) and cats(18.2%).The seroprevalence in male clogs(14.8%) and cats(21.05%) were slighlly higher than their female counterparts(11.4%in dogs and 20.0%in cats),but were not significantly differenent(P>0.05).A high proportion of dogs at 3 to 6 years of age were positive to T.gondii(20.0%)while cats with relatively high seropositivity rates were at 0 to 1 year of age(33.3%).Conclusions:The prevalence of T.gondii infection in dogs and cats in Zhenjiang City was high,which is probably the main source of T.gondii infection in this area.
基金Supported by Dean of Medical Faculty of Universitas Brawijaya and Direktorat Jendral of Higher Education,Ministry of National Education and Culture of Republic Indonesia with grant number of 0636/023-04.2.16/15/2012
文摘Objective: To know the difference between chemerin and adipocyte fatty acid-binding protein(AFABP) levels in obese individuals with positive Toxoplasma gondii(T. gondii)immunoglobulin G(IgG) compared with negative T. gondii IgG.Methods: This study is a cross-sectional study by using consecutive sampling methods conducted from January to April 2013. The subjects were 57 obese individuals who were divided into obese group of positive and negative T. gondii IgG. The level of chemerin,AFABP and T. gondii IgG was done by ELISA. The data were analyzed by independent t test.Results: The results showed that the level of chemerin of positive T. gondii IgG group was significantly higher than the negative T. gondii IgG group [(70.0 ± 16.5) vs.(64.4 ± 16.1) pg/mL; P = 0.003], but there was not significant AFABP difference between seropositive and negative IgG groups [(83.6 ± 41.9) vs.(74.2 ± 36.7) pg/mL; P = 0.598].Conclusions: It can be concluded that the level of chemerin of seropositive T. gondii IgG was higher than that in the negative T. gondii IgG group.
文摘Objective:To discuss the influence of tachyzoite of Toxoplasma gondii(T.gondii) RH strain on proliferation and apoptosis of hepatoma carcinoma(HCC) H7402 cell.Methods:The HCC H7402 cell in logarithmic phase and tachyzoite of T.gondii RH strain in different concentrations(1×107/mL,2×107/mL.4×107/mL,8×107mL and 16×107/mL) were co-cultured.CCK-8was utilized to determine the inhibition rate of T.gondii tachyzoite on H7402 cell growth.Flow cytometry was used to detect the change of cell cycle.RT-PCR method was used to detect the expression of cyclinB1 and cdc2-two genes related to cell cycle.Western blot method was used to detect the expression of apoptosis-related proteins Caspase-3 and Bcl-2.Results:The tachyzoite of T.gondii RH strain can inhibit the proliferation of HCC H7402 cells.The inhibition rate of tumor cell growth increased with the increase of concentration of T.gondii tachyzoite.With the increase of concentration of T.gondii tachyzoite,the proportion of G0/G1 phase of H7402 cell increased,the proportion of S phase decreased,and PI value decreased accordingly.The expression of cyclinB1 and cdc2 genes decreased with the increase of the concentration of T.gondii tachyzoite.With the increase of the concentration of tachyzoite of T.gondii RH strain,the expression quantity of Caspase-3 in H7402 cell increased,but the expression quantity of Bcl-2protein decreased.Conclusions:T.gondii can inhibit the in vitro proliferation of HCC H7402 cell,and induce its apoptosis.This effect shows a trend of concentration-dependent increase.Moreover,it is related to the down-regulation of cyclinB1 and cdc2(cell cycle-related genes),the increase of apoptosis-related protein Caspase-3.and the decreasc of Bcl-2 expression.
基金National Natural Science Foundation of China No39400115 and Natural Science Foundation of Guang Dong No940292
文摘Objective: To produce the major surface antigen (p30) of Toxoplasma gondii from the Baculovirus Expression System. Methods: The p30 coding sequence was cloned into a transfer vector, then the recombinant baculovirus containing p30 gene was cloned and purified by the co-transfection and plaque assay. The expression and immunoactivity of the recombinant p30 were analyzed by SDS-PAGE and Western blot. The immune responses in mice for being immunized with recombinant p30 were tested. Results: About 750μg of purified (95% purity) p30 was obtained from a culture of 108 in- sect Sf21 cells. Mice in injected with the recombinant protein produced specific humoral and cellular immune responses. Immunization with p30 also prolonged the period of mice survival infected by Toxoplasma gondii. Conclusion: It is indicated that the recombinant p30 from baculovirus expression system can stimulate mice to produce effective protection from Toxo- plasma gondii infection.
基金supported by the grants from the National Special Research Fund for Public Welfare (Agriculture) of China (200803017 and 200903036-06)
文摘Nucleoside triphosphate hydrolase (NTPase) is a multifunctional enzymatic family widely existing in vivo. They can hydrolyze NTP to NMP or dNTP to dNMP to produce energy. In this article, the structure of Toxoplasma gondii NTPase is analyzed. The research progress in NT- Pase of Toxoplasrna gondii, Trypanosoma cruzi, Sarcocystis neurona and Neospora caninum was briefly reviewed.
文摘According to the published gene sequence of the major surface antigen (P30) of Toxoplasma gondii, a pair of primers were designed and synthesized. Using polymerase chain reaction (PCR), the coding sequences of P30 gene were amplified from a Chinese strain of T. gondii, The amplified gene fragment and plasmid pB220 were digested with EcoRI and BamHI and then ligated. The inserted gene fragment was sequenced by the chain termination method, the reading reveals that nucleotide sequence determined was the same as the P30 sequecne of RH strain pubilished by Burg (1988), except that one base was changed. The recombinant plasmid containing P30 gene was transformed to E. coli DH5α.After temperature inducing culture, the total cellular proteins were analysed by SDS-PAGE and Western blot. The results show that the p30 gene cloned into the plasmid could express in E. coli, and the expression product had immunogenicity.
基金supported by the Key Research Project of the Ministry of Education (105120)Educational Commission of Hubei Province of China (B20091203)
文摘[Objective] To develop a new method for serodiagnosis of swine toxoplasmosis. [Method] With the purified recombinant microneme protein 3 (rMIC3) as coating antigens, an indirect ELISA was developed for detection of antibodies against Toxoplasma gondii. [ Result] The optimal working concentration of rMIC3 was 3. 40 ug/ml, and the optimal degree of dilution of sera was 1:160. Cross-reaction was not observed between the Toxoplasma gondii-positive sera and the positive sera against classical swine fever virus or some other pathogens. The developed ELISA had 92.56% coincidence rate with latex agglutination test. [ Conclusion] The developed ELISA is sensitive, rapid, specific and reproducible, and thus it can be applied in serodiagnosis and seroprevalence investigation of swine toxoplasmosis.
文摘Objective: To report two recent cases of pituitary adenoma associated with Toxoplasma gondii (T.Gondii) infection.Methods: Histological changes were observed in H & E and PAS staining sections microscopically.Immunohistochemistry was performed to classify the pituitary tumors and to confirm the diagnosis of T.gondii.Results: The cases were 43- and 19-year-old females, in which the latter one was a recurring case, and radiology examination showed that tumors existed in sellar region.Microscopically, the tumors consisted of small homogenous polygonal or round cells with abundant eosinophilic granular cytoplasm.Immunohistochemistry revealed they were prolactin-producing adenomas.Interestingly, we found toxoplasma infection in the tumor tissues, being confirmed by T.gondii sepicific antibody immunohistochemistry.Conclusion: The association of pituitary adenoma with toxoplasma raises the possibility that T.gondii may be involved in the development of certain cases of pituitary adenoma.
文摘Several researchers have investigated the association of numerous opportunistic pathogens with HIV, little is documented on its association with T. gondii in our environment. We investigated the prevalence of T. gondii immunoglobulins G and M (IgG and IgM) in HIV positive individuals in relation to their cluster of differentiation 4 (CD4) cells count. IgG, IgM and CD4 were assayed using enzyme immunoassay (EIA) and flowcytometry respectively. 341 HIV positive individuals were studied in the present research, 30 (8.7%) of them had T. gondii IgG and IgM, 297 subjects had CD4 cells count a range of 200-400 cells/μL, 27 (9.7%) and 2 (0.6%) of which had T. gondii IgG and IgM respectively. Of the 44 HIV positive subjects with CD4 〉 400 cells/μL, one (2.2%) was positive for T. gondii IgG. In the control group, all the 177 had CD4 〉 400 cells/μL of which, one (0.5%) had T. gondii IgG. The prevalence of T. gondii infection was significantly higher in HIV positive individuals than in controls (P 〈 0.05). Male subjects in the age bracket 18-30 years had significantly higher prevalence when compared to other groups (P 〈 0.05). Although the present findings revealed a low prevalence of T. gondii antibodies in HIV infection, this suggests that a differential toxoplasmosis diagnosis is also necessary in cases of encephalitis in HIV infection.