Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “TOXOPLASMA”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 685 records · Page 38Linked to original sources
PubMed2003

Diagnostic value of tests for Toxoplasma gondii-specific antibodies in patients undergoing bone marrow transplantation.

The value of Toxoplasma gondii-specific antibodies for the diagnosis of reactivated toxoplasmosis in immunocompromised patients is controversely discussed. The present study was performed to investigate the value of testing for antibodies against Toxoplasma gondii in patients undergoing bone marrow transplantation (BMT). Of 75 patients enrolled in the study, 53 (70.7%) were seropositive before BMT. Of these, 7 (13.2%) developed parasitemia after BMT as detected by polymerase chain reaction (PCR); three of these developed clinical symptoms compatible with reactivated toxoplasmosis that resulted in fatal toxoplasmosis in two cases. We did not detect specific antibody patterns or changes in specific antibody titers that could have predicted the development of parasitemia. Notably, 18 (81.8%) of 22 patients without specific IgG before BMT showed anti-T. gondii IgG after BMT, but none of them developed parasitemia. The results of the present study indicate that blood from both the donor and the recipient should be tested before BMT. Seronegative patients should be tested regularly after BMT to detect primary infections. Routine serological monitoring of patients seropositive before BMT does not contribute to the diagnosis of reactivated disease following BMT. In contrast, blood of seropositive patients should be screened by polymerase chain reaction (PCR) for Toxoplasma-specific DNA for the diagnosis of reactivation of infection with T. gondii.

Animals↗
PubMed2004

Development of a sensitive polymerase chain reaction method for the detection of Toxoplasma gondii in water.

Toxoplasma gondii is becoming a potential threat for public water supplies worldwide, as demonstrated by the occurrence of waterborne toxoplasmosis outbreaks in developing countries as well as industrialised countries. The aim of the present study was to develop a sensitive molecular approach (PCR) for the detection of Toxoplasma oocysts in water. Sporulated and unsporulated T. gondii oocysts (strains DX and AHC1) were isolated from faeces of laboratory-infected cats. After purification and enumeration, oocysts were spiked into 1 -L water replicates and concentrated using centrifugation, Al2(SO4)3 or Fe2(SO4)3 flocculation. DNA was extracted from the concentrated pellets, and a universal primer and a T. gondii-specific primer were selected to amplify a region at the small subunit ribosomal RNA gene. A theoretical detection limit of 0.1 oocysts was achieved for samples that had been concentrated using centrifugation or Al2(SO4)3 flocculation. No PCR products were generated for samples that had been pre-treated using Fe2(SO4)3 flocculation. The final target would be the development of a complete technique able to work as a diagnostic tool for the detection of Toxoplasma in environmental and drinking water.

Animals↗
PubMed2005

[Soluble expression and characterization of the immunoreactive multiepitope antigen of Toxoplasma gondii in E.coli].

OBJECTIVE: To obtain soluble expression product of immunoreactive recombinant multiepitope antigen of Toxoplasma gondii from E.coli. METHODS: The gene encoding the multiple epitopes (MEG) of Toxoplasma gondii was amplified by PCR from the original plasmid containing MEG gene and cloned into the prokaryotic soluble expression vector pET32a. After identification by enzyme digestion and sequencing, the positive recombinant plasmid pET32a-MEG was transformed into BL21(DE3), which was induced with IPTG for expression of the target antigen. The relative molecular mass, solubility and antigenicity of the expression products were analyzed by SDS-PAGE and Western blotting. RESULTS: The recombinant expression plasmid pET32a-MEG was successfully constructed and the highly efficient expression of the antigen was achieved after IPTG induction of E.coli. Improvement of the induction condition increased the expression product which accounted for about 28% of the total bacterial protein. The target protein, with good solubility and a relative molecular mass of about 31 000, was purified by immobilized metal affinity chromatography (Ni-NTA resin) and could be well recognized by mouse and rabbit antisera derived by infection of the animals with Toxoplasma gondii B36 and RH, respectively. CONCLUSION: The recombinant multiepitope antigen has good antigenicity and potential value in diagnosis and vaccine development of toxoplasmosis.

Animals↗
PubMed1992

Exposure to Toxoplasma gondii and cat ownership in Nova Scotia.

In this survey, 998 children and adolescents between 7 months and 17 years of age who attended a hospital diagnostic center in the city of Halifax, Nova Scotia, for routine evaluation were tested for Toxoplasma gondii antibody. The 5.2% prevalence rate of antibody for children living in the outlying rural areas was significantly higher than the 1.1% rate among the urban children (P = .0006). Seroprevalence increased with age for both rural and urban children. Cat ownership was associated with antibodies to Toxoplasma among rural children but not urban children. Rural children who lived in a house with more than one cat were two times more likely to be infected than children who had one cat and three times more likely to be infected than children with no cats. The geometric mean titer was also significantly higher among the rural children with more than one cat, 1:152, than rural children with one or no cats, 1:63 (P = .02). In light of these findings for children and adolescents, the association of Toxoplasma infection with cat ownership needs to be thoroughly evaluated among pregnant women in rural areas.

Adolescent↗
PubMedDate not supplied

[Antigenic differentiation among 3 life-cycle stages of Toxoplasma gondii using fluorescent antibodies].

Antigenic differentiation between three stages of the life cycle of Toxoplasma gondii by fluorescent antibodies. Antisera were prepared in three groups of twenty mice each with three different antigens of Toxoplasma gondii: the first group was inoculated with tachyzoites of RH strain and received sulfadiazine treatment; the second with tissue cysts of T-100-cat-6751 strain and the third with oocysts of the same strain, both without treatment. In the indirect immunofluorescent antibody technique each antigen was tested with its homologous and heterologous antisera, determining qualitative and quantitative antigenic differences according to the fluorescence patterns. Some stages of Toxoplasma when reacting with their heterologous antibodies showed a central, partial posterior or total fluorescence during a certain period of development. The difference in fluorescence was sufficient to distinguish whether the origin of the infection was via cyst, oocysts and/or via tachyzoite when observation was made before day 65 post-infection.

Animals↗
PubMed2006

Occurrence of Toxoplasma gondii in water from wells located on farms.

Among various species of parasitic protozoans which may contaminate drinking water, Toxoplasma gondii is of a special importance due to the high incidence of infections with this parasite noted in animals and humans. The objective of this study was to determine the frequency of occurrence of T. gondii in drinking water on farms in the area of the Lublin province (eastern Poland) with respect to health risk among the inhabitants, and to assess the role of water in the transmission of Toxoplasma infections in the rural environment. Studies were conducted on 87 farms located in the Lublin province, 14 of which were classified as possessing a good hygienic state, and 73 as possessing a poor hygienic state. A total number of 114 drinking water samples were taken, 80 samples from shallow household wells with a windlass, 16 from deep wells with a pump, and 18 from the water supply system. In microscopic and PCR examinations of 114 water samples, T. gondii was found in 15 (13.2%) and 31 (27.2%) of samples, respectively. The presence of T. gondii DNA detected by PCR test was found significantly more frequently in water samples from the shallow windlass-operated wells than in those from deep wells (p < 0.05) and water supply system (p < 0.01). Water samples collected from shallow wells located on farms of poor hygienic state contained significantly more frequently DNA of T. gondii than samples from shallow wells located on farms of good hygienic state (43.1% vs. 13.3%, p < 0.05). In 26.3% of water samples, oocysts of other protozoans were found belonging to Isospora, Eimeria, and Cryptosporidium. Serologic examinations for the presence of anti-Toxoplasma antibodies conducted among 99 inhabitants of the farms where household wells were used showed 64.6% of seropositive results in IgG class antibodies and 1.0% in IgM class antibodies. Clinical cases of toxoplasmosis were also noted. In the total population examined, a positive correlation was observed between the consumption of unboiled well water and the presence of antibodies against T. gondii (p < 0.05), this correlation being especially strong on farms of poor hygienic state enclosing shallow wells (p < 0.001). In conclusion, the recorded presence of T. gondii in well water provides an evidence of the potential risk of waterborne infection for humans and animals. Therefore, it seems necessary to implement prophylactic actions on the endangered farms.

Animals↗
PubMed2006

[Effect of chronic Toxoplasma infection on the spatial learning and memory capability in mice].

OBJECTIVE: To investigate the effect of chronic infection of Toxoplasma gondii on the spatial learning and memory capability in mice. METHODS: Toxoplasma tachyzoites (RH strain) were reanimated at 37 degrees C after 15 days' storage at -20 degrees C, and injected intraperitoneally to mice of the experimental group each with 7.7 x 10(5). Normal saline was given to the control group, 0.5 ml per mouse. Two months later, all mice were tested in the Morris Water Maze. Smears of the mice brain homogenate and pathological sections were examined. RESULTS: (1) The density of cysts in the brain homogenate was 15/HP, and there was no evident pathological change in the hippocampus and adjacent areas of mice in the brain in the experimental mice. (2) Latency to platform, cumulative distance to the platform, total distance traveled in both experimental and control groups decreased significantly with the increase of training days (P < 0.01). The latency and cumulative distance in experimental group were significantly longer than that of the control group (P < 0.01). (3) The searching strategy of mice in the experimental group was significantly different from that of the control group. CONCLUSION: Toxoplasma tachyzoites can induce chronic infection in mice and the infection can damage at some extent the spatial learning and memory capability of mice.

Animals↗
PubMed2006

[In vitro effect of combined traditional Chinese medicine (Changqing capsule) on the tachyzoites of Toxoplasma gondii].

OBJECTIVE: To detect the in vitro effect of the traditional Chinese medicine on the tachyzoites of Toxoplasma gondii. METHODS: Supernatant (1.5 ml) of different doses of the traditional Chinese medicine (Changqing capsule) was collected by normal saline immersion and 2.5 x 10(4) Toxoplasma gondii tachyzoites were added in each paste well for 8 hours. Spiramycin, pyrimethamine and azithromycin in different doses were used as controls. Normal saline was used as negative control. Mice were inoculated with drug-treated tachyzoites intraperitoneally or intragastrically. The normal mice were subcultured after 8 days for 3 generations. RESULTS: The incident number of the infected mice was significantly different among groups with different drugs and doses: 2/60, 16/60, 10/60 and 10/60 in the groups of Changqing capsule, spiramycin, pyrimethamine and azithromycin respectively (P < 0.05). No mice were found incident in groups of high and medium dose Changqing capsule while 2 out of 20 found sick in the low dose group (P < 0.05). The subculture observation showed that 2 and 1 mice in the first generation of the low dose Changqing capsule group inoculated intraperitonelly and intragastrically were found infected respectively. 2 mice of the second generation in low dose spiramycin group and 1 mouse of the third generation in low dose pyrimethamine group were also found infected. CONCLUSION: The in vitro killing effect of the Changqing capsule on the tachyzoites of Toxoplasma gondii is better than the current clinical drugs and shows a positive correlation with the dosages.

Animals↗
PubMed1991

Seroprevalence of anti-Toxoplasma IgG in Canadian swine.

In 1990, 1443 sera randomly selected by computer generated random numbers from a bank of greater than 15,000 sera collected earlier from sows at slaughter in various geographic regions of Canada were tested for anti-Toxoplasma immunoglobin G (IgG) by the modified direct agglutination test. One hundred and thirty-six (9.4%) samples were positive for anti-Toxoplasma IgG while 36 (2.5%) of the sera gave borderline reactions. The highest prevalence of anti-Toxoplasma IgG was in swine originating in the Atlantic provinces and Ontario while the lowest was in swine from Manitoba and Saskatchewan.

Animals↗
PubMed1991

[The role of Toxoplasma gondii in the etiology of chronic tonsillitis in children].

Toxoplasma gondii is know to have an affinity to lymphatic tissue. The authors studied whether after infection of the child's body T. gondii does or does not determine the chronic course of tonsillitis. In 712 children with chronic tonsillitis serological examinations for toxoplasmosis were carried out by means of RVK, NIR and ELISA. Low titers of toxoplasme antibodies were found in 8.0% of the children examined. In light of the following findings the authors conclude that toxoplasme tonsillitis did not occur in their series: toxoplasma antibodies failed to be increased; their titers in seropositive children were low; toxoplasma was not isolated from tonsillar tissue; no direct microscopic evidence of the parasite could be established in smears of cell aspirate from lymph nodes regional to the palatine tonsils; the same smears failed to present the cytopathologic picture characteristic of nodal toxoplasmosis. In our ecologic conditions T. gondii is presumably not involved in the etiology of chronic tonsillitis, or it may be involved but to an epidemiologically not appreciable extent. (Tab. 10, Ref. 18).

Adolescent↗
PubMed1991

Seroepidemiology of toxoplasma gondii infection in young school children in Islamabad.

Sera, from 270 school children (age 13 to 20 years) residing in suburbs of Islamabad, were investigated for the presence of toxoplasma gondii, IgG antibodies using the enzyme linked immunosorbent assay (ELISA). The overall prevalence was 17.4%. There was no significant difference between the two sexes. Since a positive test result for IgG antibodies at any level does not eliminate the possibility of a current infection, the toxoplasma IgG antibody positive children were further tested for the presence of toxoplasma IgM antibodies by the same technique. An acute infection was indicated in 12.7% (6/47) IgG positive children. This study shows that toxoplasmosis is prevalent in adolescence in Islamabad. The presence of cats and the degree of soil contact appeared compatible with hypothesis of transmission by oocysts. Poor sanitary habits and conditions and water shortage in schools may cause parasitic infection through contact between the children. An improvement in general hygienic conditions is important in reducing the rate of transmission by oocysts. Further studies are needed to assess the possible age of exposure to this parasite in the paediatric group.

Adolescent↗
PubMed1991

CD8+ T cells from mice vaccinated against Toxoplasma gondii are cytotoxic for parasite-infected or antigen-pulsed host cells.

Mice vaccinated with a live temperature sensitive mutant (TS-4) of Toxoplasma gondii develop complete resistance to subsequent challenge with a highly virulent Toxoplasma strain (RH). Because CD8+ T cells have been demonstrated to be critical to this protective immunity in vivo, the involvement of cytotoxic T lymphocytes in the killing of infected cells in vaccinated mice was investigated. After restimulation in vitro, splenic T cells from vaccinated mice of either the BALB/c or C57BL/6 strains were found to kill syngeneic bone marrow-derived macrophages infected with TS-4 tachyzoites or preincubated with soluble T. gondii Ag. Unimmunized control mice or mice vaccinated with heat-killed TS-4 tachyzoites failed to generate significant CTL activity in vitro. Moreover, the observed lytic reaction was found to be target specific, not killing uninfected or unpulsed macrophages even when included as bystanders in the assay. Target lysis did not depend on the production by the effector cells of either a cytotoxic supernatant factor or IFN-gamma. Depletion of CD8+ cells from the splenic effector cell population, however, abrogated the cytotoxic activity, whereas depletion of CD4+ cells had little effect. The MHC restriction of the Toxoplasma-specific cytolytic reaction was confirmed in studies using effector cells from BALB/c mice and targets from congenic or mutant haplotype strains. These experiments indicated that target killing is primarily restricted by genes mapping within the H-2D/Ld loci. Together, these results establish MHC-restricted cytolysis as a major parameter of CD8+ effector function against T. gondii and indicate that, in the case of this protozoan, Ag presentation to CD8+ lymphocytes can occur as a result of either processing within infected cells or exogenous uptake of parasite Ag.

Animals↗
PubMedDate not supplied

[Ultrastructural localization of the oxydasic activity in Toxoplasma gondii (author's transl)].

Toxoplasma belonging on the RH strain were studied under a transmission electron microscope. The activities looked for were: peroxidase, cytochrome oxydase and acid phosphatase. An oxydasic cytochrome respiratory activity was seen. It is localised on the crests and on the peripheral membrane of the mitochondria of Toxoplasma gondii. In the given experimental conditions, no such activity appeared in the other intracytoplasmic organels of the parasite, nor in the vacuoles of the host-cells containing living toxoplasma but the organels of those host-cells presented an oxydasic activity.

Acid Phosphatase↗
PubMed1990

[Detection of antibodies against Toxoplasma gondii in human sera in immunoblot procedures].

Proteins of Toxoplasma lysate were separated by SDS-polyacrylamide gel electrophoresis with subsequent transfer to a nitrocellulose sheet by electrophoretic blotting. Patient human sera reacted predominant with protein fractions of Toxoplasma antigen of 94 kD and 35 kD. Human sera were tested by Toxoplasma-IgG ELISA and Immunofluorescence assay (IgG-IFAT, IgM-IFAT).

Animals↗
PubMed1985

Serodiagnosis of toxoplasma infection using a purified parasite protein (P30).

The major surface protein (P30) of Toxoplasma gondii has been purified by immunoabsorption with anti-P30 monoclonal antibodies linked to a glutardialdehyde activated affinity absorbant. SDS-PAGE analysis of the eluted material followed by silver staining showed only a single band of 30,000 mol wt. Western blotting using antibodies from a rabbit immunized with purified P30 against the total Toxoplasma extract separated by SDS-PAGE again revealed an unique antigen of 30,000 daltons. The presence of repeated epitopes within P30 was confirmed by a two-site/one-antibody radiometric assay with the purified protein. Sandwich ELISA procedures with purified P30 clearly demonstrated that all 37 tested patients with acute toxoplasmosis presented significantly high levels of IgM anti-P30 antibodies. In addition, all 40 tested patients with chronic toxoplasma infection also showed high IgG anti-P30 antibody levels. These findings represent an essential step for the development of new reagents for the diagnosis of toxoplasmosis.

Antigens, Protozoan↗
PubMed1989

[Reactivity of antigenic fractions obtained from Toxoplasma gondii evaluated with Western blotting].

A toxoplasma gondii antigen, has been obtained by sonication, separated by SDS gel electrophoresis system in 10% acrylamide and blotted onto nitrocellulose paper (Western Blot). The antigen has been tested against: serum samples from subjects T. gondii negative; serum samples from patients with acute Toxoplasma infection; serum samples from subjects who had serologic evidence of infection with T. gondii, but IgM negatives. IgG and IgM immune response has been evaluated. Gel stained with Coomassie Blue revealed 48 protein fractions; only twenty fractions reacted as antigen. In particular, we have observed that only one protein fraction has been recognized by IgM antibodies present in the serum of patient with acute Toxoplasma infection (with lymphoadenopathy); some protein fractions have been recognized only by IgG antibodies; some protein fractions have been recognized in the same time by IgG and IgM antibodies in the same serum sample.

Animals↗
PubMed1989

Epidemiologic observations on feline immunodeficiency virus and Toxoplasma gondii coinfection in cats in Baltimore, Md.

Five hundred eighty-five serum samples obtained between 1980 and 1981 from a diverse population of cats were tested by use of an indirect immunoperoxidase assay for antibodies to feline immunodeficiency virus (FIV). Results of 14 of the samples were positive (prevalence, 2.4%). The FIV-positive cats were markedly older than the overall population and frequently were coinfected (57%) with Toxoplasma gondii. The Toxoplasma titers of the FIV-positive cats were significantly (P less than 0.03) higher than those of the FIV-negative cats. The FIV-positive cats were not coinfected with FeLV. Our findings suggested that FIV-associated immunosuppression may be a factor in active Toxoplasma infection in adult cats.

Age Factors↗
PubMed1989

[Prevalence of antibodies against Toxoplasma gondii, rubella virus, cytomegalovirus and herpes simplex virus in pregnant women of Catalonia].

A seroepidemiological survey was carried out to evaluate the prevalence of antibodies against toxoplasma, rubella virus, cytomegalovirus (CMV) and herpes simplex virus in pregnant women from Catalonia during 1985. The study was carried out in a representative sample of the pregnant women cared for in public and private hospitals from Catalonia, which was selected in maternal clinics by random sampling. Antibody measurements were carried out with the following techniques: toxoplasma, IFI (positive values greater than or equal to 1:10); rubella virus, Iha (greater than or equal to 1:10); CMV and herpes simplex virus, CF (greater than or equal to 1:10). 50.21% of pregnant women had antibodies against toxoplasma, 97.48% against rubella virus, 73.31% against CMV, and 80.93% against herpes simplex virus. The presence of antibodies against CMV and herpes simplex virus were significantly associated ( less than 0.00001). The demographic and socioeconomic variables associated with the prevalence of antibodies were analyzed, and they were compared with other results from the literature.

Animals↗