WorldWideScience

Sample records for gondii microneme protein

  1. Research advances in interactions related to Toxoplasma gondii microneme proteins.

    Science.gov (United States)

    Liu, Qing; Li, Fa-Cai; Zhou, Chun-Xue; Zhu, Xing-Quan

    2017-05-01

    Toxoplasma gondii microneme proteins (TgMICs), secreted by micronemes upon contact with host cells, are reported to play important roles in multiple stages of the T. gondii life cycle, including parasite motility, invasion, intracellular survival, and egress from host cells. Meanwhile, during these processes, TgMICs participate in many protein-protein and protein-carbohydrate interactions, such as undergoing proteolytic maturation, binding to aldolase, engaging the host cell receptors and forming the moving junction (MJ), relying on different types of ectodomains, transmembrane (TM) domains and cytoplasmic domains (CDs). In this review, we summarize the research advances in protein-protein and protein-carbohydrate interactions related to TgMICs, and their intimate associations with corresponding biological processes during T. gondii infection, which will contribute to an improved understanding of the molecular pathogenesis of T. gondii infection, and provide a basis for developing effective control strategies against T. gondii. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Protection induced by virus-like particles containing Toxoplasma gondii microneme protein 8 against highly virulent RH strain of Toxoplasma gondii infection.

    Directory of Open Access Journals (Sweden)

    Su-Hwa Lee

    Full Text Available Toxoplasma gondii (T. gondii microneme protein 8 (MIC8 represents a novel, functional distinct invasion factor. In this study, we generated virus-like particles (VLPs targeting Toxoplasma gondii MIC8 for the first time, and investigated the protection against highly virulent RH strain of T. gondii in a mouse model. We found that VLP vaccination induced Toxoplasma gondii-specific IgG and IgG1 antibody responses in the sera. Upon challenge infection with RH strain of T. gondii tachyzoites, vaccinated mice showed a significant increase of both IgG antibodies in sera and IgA antibodies in feces compared to those before challenge, and a rapid expansion of both germinal center B cell (B220+, GL7+ and T cell (CD4+, CD8+ populations. Importantly, intranasally immunized mice showed higher neutralizing antibodies and displayed no proinflammatory cytokine IFN-γ in the spleen. Mice were completely protected from a lethal challenge infection with the highly virulent T. gondii (RH showing no body weight loss (100% survival. Our study shows the effective protection against T. gondii infection provided by VLPs containing microneme protein 8 of T. gondii, thus indicating a potential T. gondii vaccine candidate.

  3. Protection induced by virus-like particles containing Toxoplasma gondii microneme protein 8 against highly virulent RH strain of Toxoplasma gondii infection.

    Science.gov (United States)

    Lee, Su-Hwa; Kim, Ah-Ra; Lee, Dong-Hun; Rubino, Ilaria; Choi, Hyo-Jick; Quan, Fu-Shi

    2017-01-01

    Toxoplasma gondii (T. gondii) microneme protein 8 (MIC8) represents a novel, functional distinct invasion factor. In this study, we generated virus-like particles (VLPs) targeting Toxoplasma gondii MIC8 for the first time, and investigated the protection against highly virulent RH strain of T. gondii in a mouse model. We found that VLP vaccination induced Toxoplasma gondii-specific IgG and IgG1 antibody responses in the sera. Upon challenge infection with RH strain of T. gondii tachyzoites, vaccinated mice showed a significant increase of both IgG antibodies in sera and IgA antibodies in feces compared to those before challenge, and a rapid expansion of both germinal center B cell (B220+, GL7+) and T cell (CD4+, CD8+) populations. Importantly, intranasally immunized mice showed higher neutralizing antibodies and displayed no proinflammatory cytokine IFN-γ in the spleen. Mice were completely protected from a lethal challenge infection with the highly virulent T. gondii (RH) showing no body weight loss (100% survival). Our study shows the effective protection against T. gondii infection provided by VLPs containing microneme protein 8 of T. gondii, thus indicating a potential T. gondii vaccine candidate.

  4. Expression and Isolation of Recombinant Microneme 3 (MIC3 Protein of Toxoplasma gondii Local Isolate on Eschericia coli (BL21

    Directory of Open Access Journals (Sweden)

    D Indrasanti

    2011-05-01

    Full Text Available Abstract. Toxoplasmosis is a disease that infects all warm-blooded animals, including livestocks and humans caused by Toxoplasma gondii parasites. There are major drugs used for the therapy, though they have some effects to the patients, such as allergy, toxic and teratogenic for fetus. In addition, toxoplasmosis treatment is only effective for tachyzoites T. gondii in acute infection, while tissue cysts cannot be eradicated in chronic toxoplasmosis Tissue cysts of T. gondii contained in meat that are consumed by humans and meat-derived products may be important sources of infection for humans. Microneme protein (MIC is one of proteins that belongs to excretory-secretory antigens (ESAs of Toxoplasma gondii. Microneme 3 protein (MIC3 is the protein that plays an important role in the invasion process during cell infection as a mediator attachment parasite to the host cell. Recombinant MIC3 protein has been already used for the detection of toxoplasmosis and it could induce humoral and cellular immune response in experimental animals. The aim of this research was to express MIC3 recombinant protein of T. gondii from local isolate that was cloned into expression vector and transformed to E. coli BL21. In the future, recombinant protein MIC3 can be used for vaccine candidate and diagnostic tools for toxoplasmosis in animals and humans. Gene of MIC3 T. gondii local isolate (1.2 Kbp was cloned into expression vector pET-32a(+ (5.9 Kbp and transformed to Escherichia coli BL21. Protein from plasmid recombinant (7.1 Kbp was expressed and performed by culturing recombinant bacteria into LB medium containing ampicillin and IPTG. Recombinant protein was isolated by sonication method and identified using SDS-PAGE. Finally, the recombinant protein was analyzed by immunoblotting using anti-ESAs polyclonal antibody. In conclusion, expression of the MIC3 gene with ~108 kDa has been successfully performed by cloning gene encoding for MIC3 protein of T. gondii

  5. Expression and Isolation of Recombinant Microneme 3 (MIC3 Protein of Toxoplasma gondii Local Isolate on Eschericia coli (BL21

    Directory of Open Access Journals (Sweden)

    D Indrasanti

    2011-05-01

    Full Text Available Toxoplasmosis is a disease that infects all warm-blooded animals, including livestocks and humans caused by Toxoplasma gondii parasites. There are major drugs used for the therapy, though they have some effects to the patients, such as allergy, toxic and teratogenic for fetus. In addition, toxoplasmosis treatment is only effective for tachyzoites T. gondii in acute infection, while tissue cysts cannot be eradicated in chronic toxoplasmosis Tissue cysts of T. gondii contained in meat that are consumed by humans and meat-derived products may be important sources of infection for humans. Microneme protein (MIC is one of proteins that belongs to excretory-secretory antigens (ESAs of Toxoplasma gondii. Microneme 3 protein (MIC3 is the protein that plays an important role in the invasion process during cell infection as a mediator attachment parasite to the host cell. Recombinant MIC3 protein has been already used for the detection of toxoplasmosis and it could induce humoral and cellular immune response in experimental animals. The aim of this research was to express MIC3 recombinant protein of T. gondii from local isolate that was cloned into expression vector and transformed to E. coli BL21. In the future, recombinant protein MIC3 can be used for vaccine candidate and diagnostic tools for toxoplasmosis in animals and humans. Gene of MIC3 T. gondii local isolate (1.2 Kbp was cloned into expression vector pET-32a(+ (5.9 Kbp and transformed to Escherichia coli BL21. Protein from plasmid recombinant (7.1 Kbp was expressed and performed by culturing recombinant bacteria into LB medium containing ampicillin and IPTG. Recombinant protein was isolated by sonication method and identified using SDS-PAGE. Finally, the recombinant protein was analyzed by immunoblotting using anti-ESAs polyclonal antibody. In conclusion, expression of the MIC3 gene with ~108 kDa has been successfully performed by cloning gene encoding for MIC3 protein of T. gondii local isolate

  6. Dual role of the Toxoplasma gondii clathrin adaptor AP1 in the sorting of rhoptry and microneme proteins and in parasite division.

    Directory of Open Access Journals (Sweden)

    Kannan Venugopal

    2017-04-01

    Full Text Available Toxoplasma gondii possesses a highly polarized secretory system, which efficiently assembles de novo micronemes and rhoptries during parasite replication. These apical secretory organelles release their contents into host cells promoting parasite invasion and survival. Using a CreLox-based inducible knock-out strategy and the ddFKBP over-expression system, we unraveled novel functions of the clathrin adaptor complex TgAP1. First, our data indicate that AP1 in T. gondii likely functions as a conserved heterotetrameric complex composed of the four subunits γ, β, μ1, σ1 and interacts with known regulators of clathrin-mediated vesicular budding such as the unique ENTH-domain containing protein, which we named Epsin-like protein (TgEpsL. Disruption of the μ1 subunit resulted in the mis-sorting of microneme proteins at the level of the Trans-Golgi-Network (TGN. Furthermore, we demonstrated that TgAP1 regulates rhoptry biogenesis by activating rhoptry protein exit from the TGN, but also participates in the post-Golgi maturation process of preROP compartments into apically anchored club-shaped mature organelles. For this latter activity, our data indicate a specific functional relationship between TgAP1 and the Rab5A-positive endosome-like compartment. In addition, we unraveled an original role for TgAP1 in the regulation of parasite division. APμ1-depleted parasites undergo normal daughter cell budding and basal complex assembly but fail to segregate at the end of cytokinesis.

  7. Vaccination with Recombinant Microneme Proteins Confers Protection against Experimental Toxoplasmosis in Mice.

    Directory of Open Access Journals (Sweden)

    Camila Figueiredo Pinzan

    Full Text Available Toxoplasmosis, a zoonotic disease caused by Toxoplasma gondii, is an important public health problem and veterinary concern. Although there is no vaccine for human toxoplasmosis, many attempts have been made to develop one. Promising vaccine candidates utilize proteins, or their genes, from microneme organelle of T. gondii that are involved in the initial stages of host cell invasion by the parasite. In the present study, we used different recombinant microneme proteins (TgMIC1, TgMIC4, or TgMIC6 or combinations of these proteins (TgMIC1-4 and TgMIC1-4-6 to evaluate the immune response and protection against experimental toxoplasmosis in C57BL/6 mice. Vaccination with recombinant TgMIC1, TgMIC4, or TgMIC6 alone conferred partial protection, as demonstrated by reduced brain cyst burden and mortality rates after challenge. Immunization with TgMIC1-4 or TgMIC1-4-6 vaccines provided the most effective protection, since 70% and 80% of mice, respectively, survived to the acute phase of infection. In addition, these vaccinated mice, in comparison to non-vaccinated ones, showed reduced parasite burden by 59% and 68%, respectively. The protective effect was related to the cellular and humoral immune responses induced by vaccination and included the release of Th1 cytokines IFN-γ and IL-12, antigen-stimulated spleen cell proliferation, and production of antigen-specific serum antibodies. Our results demonstrate that microneme proteins are potential vaccines against T. gondii, since their inoculation prevents or decreases the deleterious effects of the infection.

  8. Vaccination with Recombinant Microneme Proteins Confers Protection against Experimental Toxoplasmosis in Mice.

    Science.gov (United States)

    Pinzan, Camila Figueiredo; Sardinha-Silva, Aline; Almeida, Fausto; Lai, Livia; Lopes, Carla Duque; Lourenço, Elaine Vicente; Panunto-Castelo, Ademilson; Matthews, Stephen; Roque-Barreira, Maria Cristina

    2015-01-01

    Toxoplasmosis, a zoonotic disease caused by Toxoplasma gondii, is an important public health problem and veterinary concern. Although there is no vaccine for human toxoplasmosis, many attempts have been made to develop one. Promising vaccine candidates utilize proteins, or their genes, from microneme organelle of T. gondii that are involved in the initial stages of host cell invasion by the parasite. In the present study, we used different recombinant microneme proteins (TgMIC1, TgMIC4, or TgMIC6) or combinations of these proteins (TgMIC1-4 and TgMIC1-4-6) to evaluate the immune response and protection against experimental toxoplasmosis in C57BL/6 mice. Vaccination with recombinant TgMIC1, TgMIC4, or TgMIC6 alone conferred partial protection, as demonstrated by reduced brain cyst burden and mortality rates after challenge. Immunization with TgMIC1-4 or TgMIC1-4-6 vaccines provided the most effective protection, since 70% and 80% of mice, respectively, survived to the acute phase of infection. In addition, these vaccinated mice, in comparison to non-vaccinated ones, showed reduced parasite burden by 59% and 68%, respectively. The protective effect was related to the cellular and humoral immune responses induced by vaccination and included the release of Th1 cytokines IFN-γ and IL-12, antigen-stimulated spleen cell proliferation, and production of antigen-specific serum antibodies. Our results demonstrate that microneme proteins are potential vaccines against T. gondii, since their inoculation prevents or decreases the deleterious effects of the infection.

  9. Members of a novel protein family containing microneme adhesive repeat domains act as sialic acid-binding lectins during host cell invasion by apicomplexan parasites.

    Science.gov (United States)

    Friedrich, Nikolas; Santos, Joana M; Liu, Yan; Palma, Angelina S; Leon, Ester; Saouros, Savvas; Kiso, Makoto; Blackman, Michael J; Matthews, Stephen; Feizi, Ten; Soldati-Favre, Dominique

    2010-01-15

    Numerous intracellular pathogens exploit cell surface glycoconjugates for host cell recognition and entry. Unlike bacteria and viruses, Toxoplasma gondii and other parasites of the phylum Apicomplexa actively invade host cells, and this process critically depends on adhesins (microneme proteins) released onto the parasite surface from intracellular organelles called micronemes (MIC). The microneme adhesive repeat (MAR) domain of T. gondii MIC1 (TgMIC1) recognizes sialic acid (Sia), a key determinant on the host cell surface for invasion by this pathogen. By complementation and invasion assays, we demonstrate that TgMIC1 is one important player in Sia-dependent invasion and that another novel Sia-binding lectin, designated TgMIC13, is also involved. Using BLAST searches, we identify a family of MAR-containing proteins in enteroparasitic coccidians, a subclass of apicomplexans, including T. gondii, suggesting that all these parasites exploit sialylated glycoconjugates on host cells as determinants for enteric invasion. Furthermore, this protein family might provide a basis for the broad host cell range observed for coccidians that form tissue cysts during chronic infection. Carbohydrate microarray analyses, corroborated by structural considerations, show that TgMIC13, TgMIC1, and its homologue Neospora caninum MIC1 (NcMIC1) share a preference for alpha2-3- over alpha2-6-linked sialyl-N-acetyllactosamine sequences. However, the three lectins also display differences in binding preferences. Intense binding of TgMIC13 to alpha2-9-linked disialyl sequence reported on embryonal cells and relatively strong binding to 4-O-acetylated-Sia found on gut epithelium and binding of NcMIC1 to 6'sulfo-sialyl Lewis(x) might have implications for tissue tropism.

  10. A new microneme protein of Neospora caninum, NcMIC8 is involved in host cell invasion.

    Science.gov (United States)

    Wang, Jing; Tang, Di; Li, Wensheng; Xu, Jianhai; Liu, Qun; Liu, Jing

    2017-04-01

    Microneme proteins play an important role in the invasion process of Apicomplexan parasites through adhesion to host cells. We discovered a new N. caninum protein, NcMIC8, which is highly identical to TgMIC8. The NcMIC8 sequence has 2049 bp and no intron in the open reading fragment. It has a molecular weight of 73.8 kDa and contains a signal peptide, a transmembrane region, a low complexity region and 10 epidermal growth factor (EGF) domains. Immuno-fluorescence assay showed that NcMIC8 is located in the microneme. NcMIC8 was secreted to culture medium under stimulation of 1% ethanol, and cleaved to form the mature body of 40 kDa before transporting to microneme or during secretion. Blocking NcMIC8 using anti-NcMIC8 serum effectively inhibited host cell invasion by tachyzoites in vitro. NcMIC8 in the form of mature body interacts with NcMIC3, and the two microneme proteins form a complex probably during transportation. NcMIC8 is a new microneme protein of N. caninum and could be an attractive target for the control of neosporosis. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Characterization of Neospora caninum microneme protein 10 (NcMIC10) and its potential use as a diagnostic marker for neosporosis.

    Science.gov (United States)

    Yin, Jigang; Qu, Guanggang; Cao, Lili; Li, Qichang; Fetterer, Raymond; Feng, Xiaosheng; Liu, Quan; Wang, Guiping; Qi, Dongmei; Zhang, Xichen; Miramontes, Eliseo; Jenkins, Mark; Zhang, Naisheng; Tuo, Wenbin

    2012-06-08

    Improvements in the serological diagnosis of neosporosis are needed to differentiate acute versus chronic Neospora caninum infections. In the present study, N. caninum microneme protein 10 (NcMIC10), similar to other microneme proteins, was shown to be released in a calcium-dependent manner. NcMIC10 may be discharged during active invasion of host cells by the parasite, and thus represent an excellent marker for the diagnosis of neosporosis. In order to test this hypothesis, recombinant NcMIC10 (rNcMIC10) was expressed in Escherichia coli, and polyclonal antibodies were generated against non-overlapping fragments of the protein. A capture ELISA was developed using these antibodies, and was found to be highly accurate and reproducible with a detection range of 10-10,000 pg/ml. The anti-rNcMIC10 antibodies used in this study did not cross-react with the Toxoplasma gondii antigens. NcMIC10 was detected by the ELISA in sera of 9 out of 10 goats (90%) experimentally infected with N. caninum tachyzoites. In general, goats infected with a lower dose (10(4)) of the parasite displayed a peak in NcMIC10 levels between weeks 4 and 5 post infection. Goats infected with a higher parasite dose (10(6)) displayed a more rapid increase in NcMIC10 levels. In most animals, NcMIC10 decreased to undetectable levels by week 6 post infection. This is the first circulating Neospora antigen-based assay which may complement the existing antibody-based assays for a rapid and cost-effective definitive diagnosis of neosporosis in livestock. Published by Elsevier B.V.

  12. An Ancient Protein Phosphatase, SHLP1, Is Critical to Microneme Development in Plasmodium Ookinetes and Parasite Transmission

    Directory of Open Access Journals (Sweden)

    Eva-Maria Patzewitz

    2013-03-01

    Full Text Available Signaling pathways controlled by reversible protein phosphorylation (catalyzed by kinases and phosphatases in the malaria parasite Plasmodium are of great interest, for both increased understanding of parasite biology and identification of novel drug targets. Here, we report a functional analysis in Plasmodium of an ancient bacterial Shewanella-like protein phosphatase (SHLP1 found only in bacteria, fungi, protists, and plants. SHLP1 is abundant in asexual blood stages and expressed at all stages of the parasite life cycle. shlp1 deletion results in a reduction in ookinete (zygote development, microneme formation, and complete ablation of oocyst formation, thereby blocking parasite transmission. This defect is carried by the female gamete and can be rescued by direct injection of mutant ookinetes into the mosquito hemocoel, where oocysts develop. This study emphasizes the varied functions of SHLP1 in Plasmodium ookinete biology and suggests that it could be a novel drug target for blocking parasite transmission.

  13. Intersection of Endocytic and Exocytic Systems in Toxoplasma gondii.

    Science.gov (United States)

    McGovern, Olivia L; Rivera-Cuevas, Yolanda; Kannan, Geetha; Narwold, Andrew; Carruthers, Vern B

    2018-02-13

    Host cytosolic proteins are endocytosed by Toxoplasma gondii and degraded in its lysosome-like compartment, the VAC, but the dynamics and route of endocytic trafficking remain undefined. Conserved endocytic components and plant-like features suggest T. gondii endocytic trafficking involves transit through early and late endosome-like compartments (ELCs) and potentially the trans-Golgi network (TGN) as in plants. However, exocytic trafficking to regulated secretory organelles, micronemes and rhoptries, also proceeds through ELCs and requires classical endocytic components including a dynamin-related protein, DrpB. Here we show that host cytosolic proteins are endocytosed within 7 min post-invasion, trafficked through ELCs en route to the VAC, and degraded within 30 min. We could not definitively interpret if ingested protein is trafficked through the TGN. We also found that parasites ingest material from the host cytosol throughout the parasite cell cycle. Ingested host proteins colocalize with immature microneme proteins, proM2AP and proMIC5, in transit to the micronemes, but not with the immature rhoptry protein proRON4, indicating that endocytic trafficking of ingested protein intersects with exocytic trafficking of microneme proteins. Finally, we show that conditional expression of a DrpB dominant negative mutant increases T. gondii ingestion of host-derived proteins, suggesting that DrpB is not required for parasite endocytosis. This article is protected by copyright. All rights reserved.

  14. Cloning and expression of Toxoplasma gondii tachyzoite P22 protein

    African Journals Online (AJOL)

    Jane

    2011-08-01

    Aug 1, 2011 ... IPTG and analyzed by 12% SDS-PAGE. Expressd protein was purified by affinity chromatography and confirmed by western blot analysis. We successfully cloned and expressed T. gondii P22 protein. Key words: Toxoplasma gondii, cloning, recombinant P22. INTRODUCTION. Toxoplasma gondii is an ...

  15. Sequence Diversity in MIC6 Gene among Toxoplasma gondii Isolates from Different Hosts and Geographical Locations.

    Science.gov (United States)

    Li, Zhong-Yuan; Song, Hui-Qun; Chen, Jia; Zhu, Xing-Quan

    2015-06-01

    Toxoplasma gondii is an opportunistic protozoan parasite that can infect almost all warm-blooded animals including humans with a worldwide distribution. Micronemes play an important role in invasion process of T. gondii, associated with the attachment, motility, and host cell recognition. In this research, sequence diversity in microneme protein 6 (MIC6) gene among 16 T. gondii isolates from different hosts and geographical regions and 1 reference strain was examined. The results showed that the sequence of all the examined T. gondii strains was 1,050 bp in length, and their A + T content was between 45.7% and 46.1%. Sequence analysis presented 33 nucleotide mutation positions (0-1.1%), resulting in 23 amino acid substitutions (0-2.3%) aligned with T. gondii RH strain. Moreover, T. gondii strains representing the 3 classical genotypes (Type I, II, and III) were separated into different clusters based on the locus of MIC6 using phylogenetic analyses by Bayesian inference (BI), maximum parsimony (MP), and maximum likelihood (ML), but T. gondii strains belonging to ToxoDB #9 were separated into different clusters. Our results suggested that MIC6 gene is not a suitable marker for T. gondii population genetic studies.

  16. The Moving Junction Protein RON8 Facilitates Firm Attachment and Host Cell Invasion in Toxoplasma gondii

    Science.gov (United States)

    Straub, Kurtis W.; Peng, Eric D.; Hajagos, Bettina E.; Tyler, Jessica S.; Bradley, Peter J.

    2011-01-01

    The apicomplexan moving junction (MJ) is a highly conserved structure formed during host cell entry that anchors the invading parasite to the host cell and serves as a molecular sieve of host membrane proteins that protects the parasitophorous vacuole from host lysosomal destruction. While recent work in Toxoplasma and Plasmodium has reinforced the composition of the MJ as an important association of rhoptry neck proteins (RONs) with micronemal AMA1, little is known of the precise role of RONs in the junction or how they are targeted to the neck subcompartment. We report the first functional analysis of a MJ/RON protein by disrupting RON8 in T. gondii. Parasites lacking RON8 are severely impaired in both attachment and invasion, indicating that RON8 enables the parasite to establish a firm clasp on the host cell and commit to invasion. The remaining junction components frequently drag in trails behind invading knockout parasites and illustrate a malformed complex without RON8. Complementation of Δron8 parasites restores invasion and reveals a processing event at the RON8 C-terminus. Replacement of an N-terminal region of RON8 with a mCherry reporter separates regions within RON8 that are necessary for rhoptry targeting and complex formation from those required for function during invasion. Finally, the invasion defects in Δron8 parasites seen in vitro translate to radically impaired virulence in infected mice, promoting a model in which RON8 has a crucial and unprecedented task in committing Toxoplasma to host cell entry. PMID:21423671

  17. The moving junction protein RON8 facilitates firm attachment and host cell invasion in Toxoplasma gondii.

    Science.gov (United States)

    Straub, Kurtis W; Peng, Eric D; Hajagos, Bettina E; Tyler, Jessica S; Bradley, Peter J

    2011-03-01

    The apicomplexan moving junction (MJ) is a highly conserved structure formed during host cell entry that anchors the invading parasite to the host cell and serves as a molecular sieve of host membrane proteins that protects the parasitophorous vacuole from host lysosomal destruction. While recent work in Toxoplasma and Plasmodium has reinforced the composition of the MJ as an important association of rhoptry neck proteins (RONs) with micronemal AMA1, little is known of the precise role of RONs in the junction or how they are targeted to the neck subcompartment. We report the first functional analysis of a MJ/RON protein by disrupting RON8 in T. gondii. Parasites lacking RON8 are severely impaired in both attachment and invasion, indicating that RON8 enables the parasite to establish a firm clasp on the host cell and commit to invasion. The remaining junction components frequently drag in trails behind invading knockout parasites and illustrate a malformed complex without RON8. Complementation of Δron8 parasites restores invasion and reveals a processing event at the RON8 C-terminus. Replacement of an N-terminal region of RON8 with a mCherry reporter separates regions within RON8 that are necessary for rhoptry targeting and complex formation from those required for function during invasion. Finally, the invasion defects in Δron8 parasites seen in vitro translate to radically impaired virulence in infected mice, promoting a model in which RON8 has a crucial and unprecedented task in committing Toxoplasma to host cell entry.

  18. The moving junction protein RON8 facilitates firm attachment and host cell invasion in Toxoplasma gondii.

    Directory of Open Access Journals (Sweden)

    Kurtis W Straub

    2011-03-01

    Full Text Available The apicomplexan moving junction (MJ is a highly conserved structure formed during host cell entry that anchors the invading parasite to the host cell and serves as a molecular sieve of host membrane proteins that protects the parasitophorous vacuole from host lysosomal destruction. While recent work in Toxoplasma and Plasmodium has reinforced the composition of the MJ as an important association of rhoptry neck proteins (RONs with micronemal AMA1, little is known of the precise role of RONs in the junction or how they are targeted to the neck subcompartment. We report the first functional analysis of a MJ/RON protein by disrupting RON8 in T. gondii. Parasites lacking RON8 are severely impaired in both attachment and invasion, indicating that RON8 enables the parasite to establish a firm clasp on the host cell and commit to invasion. The remaining junction components frequently drag in trails behind invading knockout parasites and illustrate a malformed complex without RON8. Complementation of Δron8 parasites restores invasion and reveals a processing event at the RON8 C-terminus. Replacement of an N-terminal region of RON8 with a mCherry reporter separates regions within RON8 that are necessary for rhoptry targeting and complex formation from those required for function during invasion. Finally, the invasion defects in Δron8 parasites seen in vitro translate to radically impaired virulence in infected mice, promoting a model in which RON8 has a crucial and unprecedented task in committing Toxoplasma to host cell entry.

  19. Cloning and expression of Toxoplasma gondii tachyzoite P22 protein

    African Journals Online (AJOL)

    Delay in diagnosis of Toxoplasma gondii infection in pregnant women who have been infected during the first trimester of gestation can lead to death of her fetus. Serological tests based on recombinant proteins are the main diagnosis methods for the detection of anti Toxoplasma antibody in serum samples. The aim of this ...

  20. A novel PAN/apple domain-containing protein from Toxoplasma gondii: characterization and receptor identification.

    Directory of Open Access Journals (Sweden)

    Haiyan Gong

    Full Text Available Toxoplasma gondii is an intracellular parasite that invades nucleated cells, causing toxoplasmosis in humans and animals worldwide. The extremely wide range of hosts susceptible to T. gondii is thought to be the result of interactions between T. gondii ligands and receptors on its target cells. In this study, a host cell-binding protein from T. gondii was characterized, and one of its receptors was identified. P104 (GenBank Access. No. CAJ20677 is 991 amino acids in length, containing a putative 26 amino acid signal peptide and 10 PAN/apple domains, and shows low homology to other identified PAN/apple domain-containing molecules. A 104-kDa host cell-binding protein was detected in the T. gondii lysate. Immunofluorescence assays detected P104 at the apical end of extracellular T. gondii. An Fc-fusion protein of the P104 N-terminus, which contains two PAN/apple domains, showed strong affinity for the mammalian and insect cells evaluated. This binding was not related to protein-protein or protein-lipid interactions, but to a protein-glycosaminoglycan (GAG interaction. Chondroitin sulfate (CS, a kind of GAG, was shown to be involved in adhesion of the Fc-P104 N-terminus fusion protein to host cells. These results suggest that P104, expressed at the apical end of the extracellular parasite, may function as a ligand in the attachment of T. gondii to CS or other receptors on the host cell, facilitating invasion by the parasite.

  1. Toxoplasma gondii-Derived Synthetic Peptides Containing B- and T-Cell Epitopes from GRA2 Protein Are Able to Enhance Mice Survival in a Model of Experimental Toxoplasmosis.

    Science.gov (United States)

    Bastos, Luciana M; Macêdo, Arlindo G; Silva, Murilo V; Santiago, Fernanda M; Ramos, Eliezer L P; Santos, Fabiana A A; Pirovani, Carlos P; Goulart, Luiz R; Mineo, Tiago W P; Mineo, José R

    2016-01-01

    Toxoplasmosis is a zoonosis distributed all over the world, which the etiologic agent is an intracellular protozoan parasite, Toxoplasma gondii. This disease may cause abortions and severe diseases in many warm-blood hosts, including humans, particularly the immunocompromised patients. The parasite specialized secretory organelles, as micronemes, rhoptries and dense granules, are critical for the successful parasitism. The dense granule protein 2 (GRA2) is a parasite immunogenic protein secreted during infections and previous studies have been shown that this parasite component is crucial for the formation of intravacuolar membranous nanotubular network (MNN), as well as for secretion into the vacuole and spatial organization of the parasites within the vacuole. In the present study, we produced a monoclonal antibody to GRA2 (C3C5 mAb, isotype IgG2b), mapped the immunodominant epitope of the protein by phage display and built GRA2 synthetic epitopes to evaluate their ability to protect mice in a model of experimental infection. Our results showed that synthetic peptides for B- and T-cell epitopes are able to improve survival of immunized animals. In contrast with non-immunized animals, the immunized mice with both B- and T-cell epitopes had a better balance of cytokines and demonstrated higher levels of IL-10, IL-4 and IL-17 production, though similar levels of TNF-α and IL-6 were observed. The immunization with both B- and T-cell epitopes resulted in survival rate higher than 85% of the challenged mice. Overall, these results demonstrate that immunization with synthetic epitopes for both B- and T-cells from GRA2 protein can be more effective to protect against infection by T. gondii.

  2. Toxoplasma gondii-derived synthetic peptides containing B- and T-cell epitopes from GRA2 protein are able to enhance mice survival in a model of experimental toxoplasmosis

    Directory of Open Access Journals (Sweden)

    Luciana Machado Bastos

    2016-06-01

    Full Text Available Toxoplasmosis is a zoonosis distributed all over the world, which the etiologic agent is an intracellular protozoan parasite, Toxoplasma gondii. This disease may cause abortions and severe diseases in many warm-blood hosts, including humans, particularly the immunocompromised patients. The parasite specialized secretory organelles, as micronemes, rhoptries and dense granules, are critical for the successful parasitism. The dense granule protein 2 (GRA2 is a parasite immunogenic protein secreted during infections and previous studies have been shown that this parasite component is crucial for the formation of intravacuolar membranous nanotubular network (MNN, as well as for secretion into the vacuole and spatial organization of the parasites within the vacuole. In the present study, we produced a monoclonal antibody to GRA2 (C3C5 mAb, isotype IgG2b, mapped the immunodominant epitope of the protein by phage display and built GRA2 synthetic epitopes to evaluate their ability to protect mice in a model of experimental infection. Our results showed that synthetic peptides for B- and T-cell epitopes are able to improve survival of immunized animals. In contrast with non-immunized animals, the immunized mice with both B- and T-cell epitopes had a better balance of cytokines and demonstrated higher levels of IL-10, IL-4 and IL-17 production, though similar levels of TNF-alpha and IL-6 were observed. The immunization with both B- and T-cell epitopes resulted in survival rate higher than 85% of the challenged mice. Overall, these results demonstrate that immunization with synthetic epitopes for both B- and T-cells from GRA2 protein can be more effective to protect against infection by T. gondii.

  3. Protein disulfide isomerase of Toxoplasma gondii is targeted by mucosal IgA antibodies in humans

    NARCIS (Netherlands)

    Meek, Bob; Back, Jaap Willem; Klaren, Vincent N. A.; Speijer, Dave; Peek, Ron

    2002-01-01

    Mass spectrometric analysis identified a 49 kDa antigen from Toxoplasma gondii as protein disulfide isomerase (PDI). This antigen is generally recognized by IgA in tears of healthy humans. We determined the complete open reading frame and expressed PDI recombinantly. Recombinant PDI was recognized

  4. Toxoplasma gondii Sis1-like J-domain protein is a cytosolic chaperone associated to HSP90/HSP70 complex

    Science.gov (United States)

    Figueras, Maria J.; Martin, Osvaldo A.; Echeverria, Pablo C.; de Miguel, Natalia; Naguleswaran, Arunasalam; Sullivan, William J.; Corvi, Maria M.; Angel, Sergio O.

    2012-01-01

    Toxoplasma gondii is an obligate intracellular protozoan parasite in which 36 predicted Hsp40 family members were identified by searching the T. gondii genome. The predicted protein sequence from the gene ID TGME49_065310 showed an amino acid sequence and domain structure similar to Saccharomyces cerevisiae Sis1. TgSis1 did not show differences in its expression profile during alkaline stress by microarray analysis. Furthermore, TgSis1 showed to be a cytosolic Hsp40 which co-immunoprecipitated with T. gondii Hsp70 and Hsp90. Structural modeling of the TgSis1 peptide binding fragment revealed structural and electrostatic properties different from the experimental model of human Sis1-like protein (Hdj1). Based on these differences; we propose that TgSis1 may be a potentially attractive drug target for developing a novel anti-T. gondii therapy. PMID:22209934

  5. TgICMAP1 is a novel microtubule binding protein in Toxoplasma gondii.

    Directory of Open Access Journals (Sweden)

    Aoife T Heaslip

    Full Text Available The microtubule cytoskeleton provides essential structural support for all eukaryotic cells and can be assembled into various higher order structures that perform drastically different functions. Understanding how microtubule-containing assemblies are built in a spatially and temporally controlled manner is therefore fundamental to understanding cell physiology. Toxoplasma gondii, a protozoan parasite, contains at least five distinct tubulin-containing structures, the spindle pole, centrioles, cortical microtubules, the conoid, and the intra-conoid microtubules. How these five structurally and functionally distinct sets of tubulin containing structures are constructed and maintained in the same cell is an intriguing problem. Previously, we performed a proteomic analysis of the T. gondii apical complex, a cytoskeletal complex located at the apical end of the parasite that is composed of the conoid, three ring-like structures, and the two short intra-conoid microtubules. Here we report the characterization of one of the proteins identified in that analysis, TgICMAP1. We show that TgICMAP1 is a novel microtubule binding protein that can directly bind to microtubules in vitro and stabilizes microtubules when ectopically expressed in mammalian cells. Interestingly, in T. gondii, TgICMAP1 preferentially binds to the intra-conoid microtubules, providing us the first molecular tool to investigate the intra-conoid microtubule assembly process during daughter construction.

  6. Sequence Variation in Rhoptry Neck Protein 10 Gene among Toxoplasma gondii Isolates from Different Hosts and Geographical Locations.

    Science.gov (United States)

    Zhao, Yu; Zhou, Donghui; Chen, Jia; Sun, Xiaolin

    2017-01-01

    Toxoplasma gondii, as a eukaryotic parasite of the phylum Apicomplexa, can infect almost all the warm-blooded animals and humans, causing toxoplasmosis. Rhoptry neck proteins (RONs) play a key role in the invasion process of T. gondii and are potential vaccine candidate molecules against toxoplasmosis. The present study examined sequence variation in the rhoptry neck protein 10 (TgRON10) gene among 10 T. gondii isolates from different hosts and geographical locations from Lanzhou province during 2014, and compared with the corresponding sequences of strains ME49 and VEG obtained from the ToxoDB database, using polymerase chain reaction (PCR) amplification, sequence analysis, and phylogenetic reconstruction by Bayesian inference (BI) and maximum parsimony (MP). Analysis of all the 12 TgRON10 genomic and cDNA sequences revealed 7 exons and 6 introns in the TgRON10 gDNA. The complete genomic sequence of the TgRON10 gene ranged from 4759 bp to 4763 bp, and sequence variation was 0-0.6% among the 12 T. gondii isolates, indicating a low sequence variation in TgRON10 gene. Phylogenetic analysis of TgRON10 sequences showed that the cluster of the 12 T. gondii isolates was not completely consistent with their respective genotypes. TgRON10 gene is not a suitable genetic marker for the differentiation of T. gondii isolates from different hosts and geographical locations, but may represent a potential vaccine candidate against toxoplasmosis, worth further studies.

  7. Involvement of the mitogen-activated protein (MAP kinase signalling pathway in host cell invasion by Toxoplasma gondii

    Directory of Open Access Journals (Sweden)

    Robert-Gangneux F.

    2000-06-01

    Full Text Available Little is known about signalling in Toxoplasma gondii, but it is likely that protein kinases might play a key role in the parasite proliferation, differentiation and probably invasion. We previously characterized Mitogen-Activated Protein (MAP kinases in T. gondii lysates. In this study, cultured cells were tested for their susceptibility to Toxoplasma gondii infection after tachyzoite pretreatment with drugs interfering with AMP kinase activation pathways. Protein kinases inhibitors, i.e. genistein, R031-8220 and PD098059, reduced tachyzoite infectivity by 38 ± 4.5 %, 85.5 ± 9 % and 56 ± 10 %, respectively. Conversely, protein kinases activators, i.e. bombesin and PMA, markedly increased infectivity (by 202 ± 37 % and 258 ± 14 %, respectively. These results suggest that signalling pathways involving PKC and AAAP kinases play a role in host cell invasion by Toxoplasma.

  8. Targeted overexpression of cyclic AMP-dependent protein kinase subunit in Toxoplasma gondii promotes replication and virulence in host cells.

    Science.gov (United States)

    Sun, Hongchao; Wang, Suhua; Zhao, Xianfeng; Yao, Chaoqun; Zhuang, Haohan; Huang, Yechuan; Chen, Xueqiu; Yang, Yi; Du, Aifang

    2017-08-30

    Toxoplasma gondii (T. gondii) is one of the most common parasite that can infect almost any warm-blooded animals including humans. The cyclic nucleotide-dependent protein kinase (PKA) regulates a spectrum of intracellular signal pathways in many organisms. Protein kinase catalytic subunit (PKAC) is the core of the whole protein, and plays an important role in the life cycle of T.gondii. Here, T.gondii PKAC (TgPKAC) overexpression strain (TgPKAC-OE) was constructed. The growth of the TgPKAC-OE, RH△Ku80, and TgPKAC inhibition strains (TgPKAC-H89) were analysed by SYBR-green real-time PCR, and the ultrastructure was observed by transmission electron microscopy. The survival rate in mice was also recorded to analyse the virulence of the parasites. We also investigated the subcellular localization of TgPKAC in Vero cells by laser scanning microscope. We found that TgPKAC-OE strain exhibited obviously increased growth rate in Vero cells in vitro, and infected mice survived for a shorter time compared to wild type strain. Ultrastructural analysis found more autophagosomes-like structures in TgPKAC-H89 parasite compared to RH△Ku80 strain, and the relative expression level of Toxoplasma gondii autophagy-related protein (ATG8) in TgPKAC-H89 parasite was higher than wild type parasite. Laser confocal results showed that TgPKAC was mainly expressed in the cytoplasm of Vero cells. In conclusion, we hypothesized that inhibition of TgPKAC could cause autophagy of Toxoplasma gondii and then influence the replication of the parasite. TgPKAC plays an important role in parasite virulence in vivo, and the subcellular localization was successfully detected in Vero cells. Our data will provide a basis for further study of TgPKAC function and help screen drug targets of T. gondii. Copyright © 2017. Published by Elsevier B.V.

  9. Phosphorylation of mouse immunity-related GTPase (IRG resistance proteins is an evasion strategy for virulent Toxoplasma gondii.

    Directory of Open Access Journals (Sweden)

    Tobias Steinfeldt

    Full Text Available Virulence of complex pathogens in mammals is generally determined by multiple components of the pathogen interacting with the functional complexity and multiple layering of the mammalian immune system. It is most unusual for the resistance of a mammalian host to be overcome by the defeat of a single defence mechanism. In this study we uncover and analyse just such a case at the molecular level, involving the widespread intracellular protozoan pathogen Toxoplasma gondii and one of its most important natural hosts, the house mouse (Mus musculus. Natural polymorphism in virulence of Eurasian T. gondii strains for mice has been correlated in genetic screens with the expression of polymorphic rhoptry kinases (ROP kinases secreted into the host cell during infection. We show that the molecular targets of the virulent allelic form of ROP18 kinase are members of a family of cellular GTPases, the interferon-inducible IRG (immunity-related GTPase proteins, known from earlier work to be essential resistance factors in mice against avirulent strains of T. gondii. Virulent T. gondii strain ROP18 kinase phosphorylates several mouse IRG proteins. We show that the parasite kinase phosphorylates host Irga6 at two threonines in the nucleotide-binding domain, biochemically inactivating the GTPase and inhibiting its accumulation and action at the T. gondii parasitophorous vacuole membrane. Our analysis identifies the conformationally active switch I region of the GTP-binding site as an Achilles' heel of the IRG protein pathogen-resistance mechanism. The polymorphism of ROP18 in natural T. gondii populations indicates the existence of a dynamic, rapidly evolving ecological relationship between parasite virulence factors and host resistance factors. This system should be unusually fruitful for analysis at both ecological and molecular levels since both T. gondii and the mouse are widespread and abundant in the wild and are well-established model species with

  10. Toxoplasma gondii Syntaxin 6 Is Required for Vesicular Transport Between Endosomal-Like Compartments and the Golgi Complex

    Science.gov (United States)

    Jackson, Allison J; Clucas, Caroline; Mamczur, Nicola J; Ferguson, David J; Meissner, Markus

    2013-01-01

    Apicomplexans are obligate intracellular parasites that invade the host cell in an active process that relies on unique secretory organelles (micronemes, rhoptries and dense granules) localized at the apical tip of these highly polarized eukaryotes. In order for the contents of these specialized organelles to reach their final destination, these proteins are sorted post-Golgi and it has been speculated that they pass through endosomal-like compartments (ELCs), where they undergo maturation. Here, we characterize a Toxoplasma gondii homologue of Syntaxin 6 (TgStx6), a well-established marker for the early endosomes and trans Golgi network (TGN) in diverse eukaryotes. Indeed, TgStx6 appears to have a role in the retrograde transport between ELCs, the TGN and the Golgi, because overexpression of TgStx6 results in the development of abnormally shaped parasites with expanded ELCs, a fragmented Golgi and a defect in inner membrane complex maturation. Interestingly, other organelles such as the micronemes, rhoptries and the apicoplast are not affected, establishing the TGN as a major sorting compartment where several transport pathways intersect. It therefore appears that Toxoplasma has retained a plant-like secretory pathway. PMID:23962112

  11. Toxoplasma gondii: Biochemical and biophysical characterization of recombinant soluble dense granule proteins GRA2 and GRA6

    Energy Technology Data Exchange (ETDEWEB)

    Bittame, Amina [CNRS, UMR 5163, 38042 Grenoble (France); Université Grenoble Alpes, 38042 Grenoble (France); Effantin, Grégory [Université Grenoble Alpes, Institut de Biologie Structurale (IBS), 38044 Grenoble (France); CNRS, IBS, 38044 Grenoble (France); CEA, IBS, 38044 Grenoble (France); Unit for Virus Host-Cell Interactions (UVHCI), UMI 3265 (UJF-EMBL-CNRS), 38027 Grenoble (France); Pètre, Graciane; Ruffiot, Pauline; Travier, Laetitia [CNRS, UMR 5163, 38042 Grenoble (France); Université Grenoble Alpes, 38042 Grenoble (France); Schoehn, Guy; Weissenhorn, Winfried [Université Grenoble Alpes, Institut de Biologie Structurale (IBS), 38044 Grenoble (France); CNRS, IBS, 38044 Grenoble (France); CEA, IBS, 38044 Grenoble (France); Unit for Virus Host-Cell Interactions (UVHCI), UMI 3265 (UJF-EMBL-CNRS), 38027 Grenoble (France); Cesbron-Delauw, Marie-France; Gagnon, Jean [CNRS, UMR 5163, 38042 Grenoble (France); Université Grenoble Alpes, 38042 Grenoble (France); Mercier, Corinne, E-mail: corinne.mercier@ujf-grenoble.fr [CNRS, UMR 5163, 38042 Grenoble (France); Université Grenoble Alpes, 38042 Grenoble (France)

    2015-03-27

    The most prominent structural feature of the parasitophorous vacuole (PV) in which the intracellular parasite Toxoplasma gondii proliferates is a membranous nanotubular network (MNN), which interconnects the parasites and the PV membrane. The MNN function remains unclear. The GRA2 and GRA6 proteins secreted from the parasite dense granules into the PV have been implicated in the MNN biogenesis. Amphipathic alpha-helices (AAHs) predicted in GRA2 and an alpha-helical hydrophobic domain predicted in GRA6 have been proposed to be responsible for their membrane association, thereby potentially molding the MMN in its structure. Here we report an analysis of the recombinant proteins (expressed in detergent-free conditions) by circular dichroism, which showed that full length GRA2 displays an alpha-helical secondary structure while recombinant GRA6 and GRA2 truncated of its AAHs are mainly random coiled. Dynamic light scattering and transmission electron microscopy showed that recombinant GRA6 and truncated GRA2 constitute a homogenous population of small particles (6–8 nm in diameter) while recombinant GRA2 corresponds to 2 populations of particles (∼8–15 nm and up to 40 nm in diameter, respectively). The unusual properties of GRA2 due to its AAHs are discussed. - Highlights: • Toxoplasma gondii: soluble GRA2 forms 2 populations of particles. • T. gondii: the dense granule protein GRA2 folds intrinsically as an alpha-helix. • T. gondii: monomeric soluble GRA6 forms particles of 6–8 nm in diameter. • T. gondii: monomeric soluble GRA6 is random coiled. • Unusual biophysical properties of the dense granule protein GRA2 from T. gondii.

  12. Studies of Toxoplasma gondii and Plasmodium falciparum enoyl acyl carrier protein reductase and implications for the development of antiparasitic agents

    Energy Technology Data Exchange (ETDEWEB)

    Muench, Stephen P. [The Krebs Institute for Biomolecular Research, Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank, Sheffield S10 2TN (United Kingdom); Prigge, Sean T. [Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205 (United States); McLeod, Rima [Department of Ophthalmology and Visual Sciences, Paediatrics (Infectious Diseases) and Pathology and the Committees on Molecular Medicine, Genetics, Immunology and The College, The University of Chicago, Chicago, IL 60637 (United States); Rafferty, John B. [The Krebs Institute for Biomolecular Research, Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank, Sheffield S10 2TN (United Kingdom); Kirisits, Michael J. [Department of Ophthalmology and Visual Sciences, Paediatrics (Infectious Diseases) and Pathology and the Committees on Molecular Medicine, Genetics, Immunology and The College, The University of Chicago, Chicago, IL 60637 (United States); Roberts, Craig W. [Department of Immunology, University of Strathclyde, Glasgow G4 0NR, Scotland (United Kingdom); Mui, Ernest J. [Department of Ophthalmology and Visual Sciences, Paediatrics (Infectious Diseases) and Pathology and the Committees on Molecular Medicine, Genetics, Immunology and The College, The University of Chicago, Chicago, IL 60637 (United States); Rice, David W., E-mail: d.rice@sheffield.ac.uk [The Krebs Institute for Biomolecular Research, Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank, Sheffield S10 2TN (United Kingdom)

    2007-03-01

    The crystal structures of T. gondii and P. falciparum ENR in complex with NAD{sup +} and triclosan and of T. gondii ENR in an apo form have been solved to 2.6, 2.2 and 2.8 Å, respectively. Recent studies have demonstrated that submicromolar concentrations of the biocide triclosan arrest the growth of the apicomplexan parasites Plasmodium falciparum and Toxoplasma gondii and inhibit the activity of the apicomplexan enoyl acyl carrier protein reductase (ENR). The crystal structures of T. gondii and P. falciparum ENR in complex with NAD{sup +} and triclosan and of T. gondii ENR in an apo form have been solved to 2.6, 2.2 and 2.8 Å, respectively. The structures of T. gondii ENR have revealed that, as in its bacterial and plant homologues, a loop region which flanks the active site becomes ordered upon inhibitor binding, resulting in the slow tight binding of triclosan. In addition, the T. gondii ENR–triclosan complex reveals the folding of a hydrophilic insert common to the apicomplexan family that flanks the substrate-binding domain and is disordered in all other reported apicomplexan ENR structures. Structural comparison of the apicomplexan ENR structures with their bacterial and plant counterparts has revealed that although the active sites of the parasite enzymes are broadly similar to those of their bacterial counterparts, there are a number of important differences within the drug-binding pocket that reduce the packing interactions formed with several inhibitors in the apicomplexan ENR enzymes. Together with other significant structural differences, this provides a possible explanation of the lower affinity of the parasite ENR enzyme family for aminopyridine-based inhibitors, suggesting that an effective antiparasitic agent may well be distinct from equivalent antimicrobials.

  13. Studies of Toxoplasma gondii and Plasmodium falciparum enoyl acyl carrier protein reductase and implications for the development of antiparasitic agents

    International Nuclear Information System (INIS)

    Muench, Stephen P.; Prigge, Sean T.; McLeod, Rima; Rafferty, John B.; Kirisits, Michael J.; Roberts, Craig W.; Mui, Ernest J.; Rice, David W.

    2007-01-01

    The crystal structures of T. gondii and P. falciparum ENR in complex with NAD + and triclosan and of T. gondii ENR in an apo form have been solved to 2.6, 2.2 and 2.8 Å, respectively. Recent studies have demonstrated that submicromolar concentrations of the biocide triclosan arrest the growth of the apicomplexan parasites Plasmodium falciparum and Toxoplasma gondii and inhibit the activity of the apicomplexan enoyl acyl carrier protein reductase (ENR). The crystal structures of T. gondii and P. falciparum ENR in complex with NAD + and triclosan and of T. gondii ENR in an apo form have been solved to 2.6, 2.2 and 2.8 Å, respectively. The structures of T. gondii ENR have revealed that, as in its bacterial and plant homologues, a loop region which flanks the active site becomes ordered upon inhibitor binding, resulting in the slow tight binding of triclosan. In addition, the T. gondii ENR–triclosan complex reveals the folding of a hydrophilic insert common to the apicomplexan family that flanks the substrate-binding domain and is disordered in all other reported apicomplexan ENR structures. Structural comparison of the apicomplexan ENR structures with their bacterial and plant counterparts has revealed that although the active sites of the parasite enzymes are broadly similar to those of their bacterial counterparts, there are a number of important differences within the drug-binding pocket that reduce the packing interactions formed with several inhibitors in the apicomplexan ENR enzymes. Together with other significant structural differences, this provides a possible explanation of the lower affinity of the parasite ENR enzyme family for aminopyridine-based inhibitors, suggesting that an effective antiparasitic agent may well be distinct from equivalent antimicrobials

  14. Sequence Variation in Rhoptry Neck Protein 10 Gene among Toxoplasma gondii Isolates from Different Hosts and Geographical Locations

    Directory of Open Access Journals (Sweden)

    Yu ZHAO

    2017-09-01

    Full Text Available Background: Toxoplasma gondii, as a eukaryotic parasite of the phylum Apicomplexa, can infect almost all the warm-blooded animals and humans, causing toxoplasmosis. Rhoptry neck proteins (RONs play a key role in the invasion process of T. gondii and are potential vaccine candidate molecules against toxoplasmosis.Methods: The present study examined sequence variation in the rhoptry neck protein 10 (TgRON10 gene among 10 T. gondii isolates from different hosts and geographical locations from Lanzhou province during 2014, and compared with the corresponding sequences of strains ME49 and VEG obtained from the ToxoDB database, using polymerase chain reaction (PCR amplification, sequence analysis, and phylogenetic reconstruction by Bayesian inference (BI and maximum parsimony (MP. Results: Analysis of all the 12 TgRON10 genomic and cDNA sequences revealed 7 exons and 6 introns in the TgRON10 gDNA. The complete genomic sequence of the TgRON10 gene ranged from 4759 bp to 4763 bp, and sequence variation was 0-0.6% among the 12 T. gondii isolates, indicating a low sequence variation in TgRON10 gene. Phylogenetic analysis of TgRON10 sequences showed that the cluster of the 12 T. gondii isolates was not completely consistent with their respective genotypes.Conclusion: TgRON10 gene is not a suitable genetic marker for the differentiation of T. gondii isolates from different hosts and geographical locations, but may represent a potential vaccine candidate against toxoplasmosis, worth further studies.

  15. Toxoplasma gondii

    Science.gov (United States)

    Cao, Shinuo; Du, Nali; Chen, Heming; Pang, Yu; Zhang, Zhaoxia; Zheng, Jun; Jia, Honglin

    2017-10-17

    Caseinolytic peptidase B (ClpB) plays a pivotal role in suppressing and reversing protein aggregation. Toxoplasma gondii is an intracellular parasitic protozoan that infects a wide variety of mammals and birds and therefore is exposed to a broad range of living condition. We screened ToxoDB (http://ToxoDB.org) and identified 10 putative T. gondii genes encoding members of the Clp superfamily of caseinolytic proteases and chaperones. Of these, we focused on characterizing the Class I ATP-dependent molecular chaperones Tg ClpB1, Tg ClpB2, and Tg ClpB3. We found that Tg ClpB1, the most divergent of the five T. gondii Class I Clp ATPases, is cytoplasmic, Tg ClpB2 is found in the mitochondria of the parasites, and Tg ClpB3 is a ClpB with novel apicoplast localization. Knockout strains of Tg ClpB1 and Tg ClpB2 were established by CRISPR/Cas9 mutagenesis, and their complementing strains were constructed with FLAG-tag. Although knockout of Tg ClpB1 or Tg ClpB2 did not affect growth under normal circumstances, Tg ClpB1 was required for T. gondii thermotolerance. The growth, replication, and invasion capabilities of Tg ClpB1-deficient mutants were significantly inhibited after extracellular parasites were pretreated at 45°C. Moreover, Tg ClpB1 were observed at the poles of the Δ Tg ClpB1 FLAG-tagged strain treated at 42°C.

  16. Partial protective effect of intranasal immunization with recombinant Toxoplasma gondii rhoptry protein 17 against toxoplasmosis in mice.

    Directory of Open Access Journals (Sweden)

    Hai-Long Wang

    Full Text Available Toxoplasma gondii (T. gondii is an obligate intracellular protozoan parasite that infects a variety of mammals, including humans. An effective vaccine for this parasite is therefore needed. In this study, RH strain T. gondii rhoptry protein 17 was expressed in bacteria as a fusion with glutathione S-transferase (GST and the recombinant proteins (rTgROP17 were purified via GST-affinity chromatography. BALB/c mice were nasally immunised with rTgROP17, and induction of immune responses and protection against chronic and lethal T. gondii infections were investigated. The results revealed that mice immunised with rTgROP17 produced high levels of specific anti-rTgROP17 IgGs and a mixed IgG1/IgG2a response of IgG2a predominance. The systemic immune response was associated with increased production of Th1 (IFN-γand IL-2 and Th2 (IL-4 cytokines, and enhanced lymphoproliferation (stimulation index, SI in the mice immunised with rTgROP17. Strong mucosal immune responses with increased secretion of TgROP17-specific secretory IgA (SIgA in nasal, vaginal and intestinal washes were also observed in these mice. The vaccinated mice displayed apparent protection against chronic RH strain infection as evidenced by their lower liver and brain parasite burdens (59.17% and 49.08%, respectively than those of the controls. The vaccinated mice also exhibited significant protection against lethal infection of the virulent RH strain (survival increased by 50% compared to the controls. Our data demonstrate that rTgROP17 can trigger strong systemic and mucosal immune responses against T. gondii and that ROP17 is a promising candidate vaccine for toxoplasmosis.

  17. The Toxoplasma gondii cyst wall protein CST1 is critical for cyst wall integrity and promotes bradyzoite persistence

    Energy Technology Data Exchange (ETDEWEB)

    Tomita, Tadakimi; Bzik, David J.; Ma, Yan Fen; Fox, Barbara A.; Markillie, Lye Meng; Taylor, Ronald C.; Kim, Kami; Weiss, Louis M.

    2013-12-26

    Toxoplasma gondii infects up to one third of the world’s population. A key to the success of T.gondii is its ability to persist for the life of its host as bradyzoites within tissue cysts. The glycosylated cyst wall is the key structural feature that facilitates persistence and oral transmission of this parasite. We have identified CST1 (TGME49_064660) as a 250 kDa SRS (SAG1 related sequence) domain protein with a large mucin-like domain. CST1 is responsible for the Dolichos biflorus Agglutinin (DBA) lectin binding characteristic of T. gondii cysts. Deletion of CST1 results in a fragile brain cyst phenotype revealed by a thinning and disruption of the underlying region of the cyst wall. These defects are reversed by complementation of CST1. Additional complementation experiments demonstrate that the CST1-mucin domain is necessary for the formation of a normal cyst wall structure, the ability of the cyst to resist mechanical stress and binding of DBA to the cyst wall. RNA-seq transcriptome analysis demonstrated dysregulation of bradyzoite genes within the various cst1 mutants. These results indicate that CST1 functions as a key structural component that reinforces the cyst wall structure and confers essential sturdiness to the T. gondii tissue cyst.

  18. DMPD: Manipulation of mitogen-activated protein kinase/nuclear factor-kappaB-signalingcascades during intracellular Toxoplasma gondii infection. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 15361242 Manipulation of mitogen-activated protein kinase/nuclear factor-kappaB-sig...mmunol Rev. 2004 Oct;201:191-205. (.png) (.svg) (.html) (.csml) Show Manipulation of mitogen-activated protein kinase/nuclear... gondii infection. PubmedID 15361242 Title Manipulation of mitogen-activated protein kinase/nuclear factor-k

  19. Toxoplasma DJ-1 Regulates Organelle Secretion by a Direct Interaction with Calcium-Dependent Protein Kinase 1.

    Science.gov (United States)

    Child, Matthew A; Garland, Megan; Foe, Ian; Madzelan, Peter; Treeck, Moritz; van der Linden, Wouter A; Oresic Bender, Kristina; Weerapana, Eranthie; Wilson, Mark A; Boothroyd, John C; Reese, Michael L; Bogyo, Matthew

    2017-02-28

    Human DJ-1 is a highly conserved and yet functionally enigmatic protein associated with a heritable form of Parkinson's disease. It has been suggested to be a redox-dependent regulatory scaffold, binding to proteins to modulate their function. Here we present the X-ray crystal structure of the Toxoplasma orthologue Toxoplasma gondii DJ-1 (TgDJ-1) at 2.1-Å resolution and show that it directly associates with calcium-dependent protein kinase 1 (CDPK1). The TgDJ-1 structure identifies an orthologously conserved arginine dyad that acts as a phospho-gatekeeper motif to control complex formation. We determined that the binding of TgDJ-1 to CDPK1 is sensitive to oxidation and calcium, and that this interaction potentiates CDPK1 kinase activity. Finally, we show that genetic deletion of TgDJ-1 results in upregulation of CDPK1 expression and that disruption of the CDPK1/TgDJ-1 complex in vivo prevents normal exocytosis of parasite virulence-associated organelles called micronemes. Overall, our data suggest that TgDJ-1 functions as a noncanonical kinase-regulatory scaffold that integrates multiple intracellular signals to tune microneme exocytosis in T. gondii IMPORTANCE Apicomplexan parasites such as Toxoplasma and Plasmodium are obligate intracellular parasites that require the protective environment of a host cell in order to replicate and survive within a host organism. These parasites secrete effector proteins from specialized apical organelles to select and invade a chosen host cell. The secretion of these organelles is a tightly regulated process coordinated by endogenous small molecules and calcium-dependent protein kinases. We previously identified the Toxoplasma orthologue of the highly conserved protein DJ-1 as a regulator of microneme secretion, but the molecular basis for this was not known. We have now identified the molecular mechanism for how TgDJ-1 regulates microneme secretion. TgDJ-1 interacts with the kinase responsible for the secretion of these

  20. Modification of Triclosan Scaffold in Search of Improved Inhibitors for Enoyl-Acyl Carrier Protein (ACP) Reductase in Toxoplasma gondii

    Science.gov (United States)

    Stec, Jozef; Fomovska, Alina; Afanador, Gustavo A.; Muench, Stephen P.; Zhou, Ying; Lai, Bo-Shiun; Bissati, Kamal El; Hickman, Mark R.; Lee, Patty J.; Leed, Susan E.; Auschwitz, Jennifer M.; Sommervile, Caroline; Woods, Stuart; Roberts, Craig W.; Rice, David; Prigge, Sean T.; McLeod, Rima; Kozikowski, Alan P.

    2013-01-01

    Through our focused effort to discover new and effective agents against toxoplasmosis, a structure-based drug design approach was utilized to develop a series of potent inhibitors of the enoyl-acyl carrier protein (ACP) reductase (ENR) enzyme in Toxoplasma gondii (TgENR). Modifications to positions 5 and 4′ of the well-known ENR inhibitor triclosan afforded a series of 29 new analogs. Among the resulting compounds, many showed high potency and improved physicochemical properties in comparison with the lead. The most potent compounds 16a and 16c have IC50 values of 250 nM against Toxoplasma gondii tachyzoites without apparent toxicity to the host cells. Their IC50 values against the recombinant TgENR were 43 and 26 nM, respectively. Additionally, 11 other analogs in this series had IC50 values ranging from 17 to 130 nM in the enzyme-based assay. With respect to their excellent in vitro activity as well as improved drug-like properties, the lead compounds 16a and 16c are deemed to be an excellent starting point for the development of new medicines to effectively treat Toxoplasma gondii infections. PMID:23776166

  1. A Toxoplasma gondii protein with homology to intracellular type Na+/H+ exchangers is important for osmoregulation and invasion

    International Nuclear Information System (INIS)

    Francia, Maria E.; Wicher, Sarah; Pace, Douglas A.; Sullivan, Jack; Moreno, Silvia N.J.; Arrizabalaga, Gustavo

    2011-01-01

    The obligate intracellular parasite Toxoplasma gondii is exposed to a variety of physiological conditions while propagating in an infected organism. The mechanisms by which Toxoplasma overcomes these dramatic changes in its environment are not known. In yeast and plants, ion detoxification and osmotic regulation are controlled by vacuolar compartments. A novel compartment named the plant-like vacuole or vacuolar compartment (PLV/VAC) has recently been described in T.gondii, which could potentially protect extracellular tachyzoites against salt and other ionic stresses. Here, we report the molecular characterization of the vacuolar type Na + /H + exchanger in T. gondii, TgNHE3, and its co-localization with the PLV/VAC proton-pyrophosphatase (TgVP1). We have created a TgNHE3 knockout strain, which is more sensitive to hyperosmotic shock and toxic levels of sodium, possesses a higher intracellular Ca 2+ concentration [Ca 2+ ] i , and exhibits a reduced host invasion efficiency. The defect in invasion correlates with a measurable reduction in the secretion of the adhesin TgMIC2. Overall, our results suggest that the PLV/VAC has functions analogous to those of the vacuolar compartments of plants and yeasts, providing the parasite with a mechanism to resist ionic fluctuations and, potentially, regulate protein trafficking.

  2. Characterization of a nuclear pore protein sheds light on the roles and composition of the Toxoplasma gondii nuclear pore complex.

    Science.gov (United States)

    Courjol, Flavie; Mouveaux, Thomas; Lesage, Kevin; Saliou, Jean-Michel; Werkmeister, Elisabeth; Bonabaud, Maurine; Rohmer, Marine; Slomianny, Christian; Lafont, Franck; Gissot, Mathieu

    2017-06-01

    The nuclear pore is a key structure in eukaryotes regulating nuclear-cytoplasmic transport as well as a wide range of cellular processes. Here, we report the characterization of the first Toxoplasma gondii nuclear pore protein, named TgNup302, which appears to be the orthologue of the mammalian Nup98-96 protein. We produced a conditional knock-down mutant that expresses TgNup302 under the control of an inducible tetracycline-regulated promoter. Under ATc treatment, a substantial decrease of TgNup302 protein in inducible knock-down (iKD) parasites was observed, causing a delay in parasite proliferation. Moreover, the nuclear protein TgENO2 was trapped in the cytoplasm of ATc-treated mutants, suggesting that TgNup302 is involved in nuclear transport. Fluorescence in situ hybridization revealed that TgNup302 is essential for 18S RNA export from the nucleus to the cytoplasm, while global mRNA export remains unchanged. Using an affinity tag purification combined with mass spectrometry, we identified additional components of the nuclear pore complex, including proteins potentially interacting with chromatin. Furthermore, reverse immunoprecipitation confirmed their interaction with TgNup302, and structured illuminated microscopy confirmed the NPC localization of some of the TgNup302-interacting proteins. Intriguingly, facilitates chromatin transcription complex (FACT) components were identified, suggesting the existence of an NPC-chromatin interaction in T. gondii. Identification of TgNup302-interacting proteins also provides the first glimpse at the NPC structure in Apicomplexa, suggesting a structural conservation of the NPC components between distant eukaryotes.

  3. Secretion of Rhoptry and Dense Granule Effector Proteins by Nonreplicating Toxoplasma gondii Uracil Auxotrophs Controls the Development of Antitumor Immunity

    Science.gov (United States)

    Fox, Barbara A.; Sanders, Kiah L.; Rommereim, Leah M.; Bzik, David J.

    2016-01-01

    Nonreplicating type I uracil auxotrophic mutants of Toxoplasma gondii possess a potent ability to activate therapeutic immunity to established solid tumors by reversing immune suppression in the tumor microenvironment. Here we engineered targeted deletions of parasite secreted effector proteins using a genetically tractable Δku80 vaccine strain to show that the secretion of specific rhoptry (ROP) and dense granule (GRA) proteins by uracil auxotrophic mutants of T. gondii in conjunction with host cell invasion activates antitumor immunity through host responses involving CD8α+ dendritic cells, the IL-12/interferon-gamma (IFN-γ) TH1 axis, as well as CD4+ and CD8+ T cells. Deletion of parasitophorous vacuole membrane (PVM) associated proteins ROP5, ROP17, ROP18, ROP35 or ROP38, intravacuolar network associated dense granule proteins GRA2 or GRA12, and GRA24 which traffics past the PVM to the host cell nucleus severely abrogated the antitumor response. In contrast, deletion of other secreted effector molecules such as GRA15, GRA16, or ROP16 that manipulate host cell signaling and transcriptional pathways, or deletion of PVM associated ROP21 or GRA3 molecules did not affect the antitumor activity. Association of ROP18 with the PVM was found to be essential for the development of the antitumor responses. Surprisingly, the ROP18 kinase activity required for resistance to IFN-γ activated host innate immunity related GTPases and virulence was not essential for the antitumor response. These data show that PVM functions of parasite secreted effector molecules, including ROP18, manipulate host cell responses through ROP18 kinase virulence independent mechanisms to activate potent antitumor responses. Our results demonstrate that PVM associated rhoptry effector proteins secreted prior to host cell invasion and dense granule effector proteins localized to the intravacuolar network and host nucleus that are secreted after host cell invasion coordinately control the

  4. Toxoplasma gondii Cyclic AMP-Dependent Protein Kinase Subunit 3 Is Involved in the Switch from Tachyzoite to Bradyzoite Development

    Directory of Open Access Journals (Sweden)

    Tatsuki Sugi

    2016-05-01

    Full Text Available Toxoplasma gondii is an obligate intracellular apicomplexan parasite that infects warm-blooded vertebrates, including humans. Asexual reproduction in T. gondii allows it to switch between the rapidly replicating tachyzoite and quiescent bradyzoite life cycle stages. A transient cyclic AMP (cAMP pulse promotes bradyzoite differentiation, whereas a prolonged elevation of cAMP inhibits this process. We investigated the mechanism(s by which differential modulation of cAMP exerts a bidirectional effect on parasite differentiation. There are three protein kinase A (PKA catalytic subunits (TgPKAc1 to -3 expressed in T. gondii. Unlike TgPKAc1 and TgPKAc2, which are conserved in the phylum Apicomplexa, TgPKAc3 appears evolutionarily divergent and specific to coccidian parasites. TgPKAc1 and TgPKAc2 are distributed in the cytomembranes, whereas TgPKAc3 resides in the cytosol. TgPKAc3 was genetically ablated in a type II cyst-forming strain of T. gondii (PruΔku80Δhxgprt and in a type I strain (RHΔku80Δhxgprt, which typically does not form cysts. The Δpkac3 mutant exhibited slower growth than the parental and complemented strains, which correlated with a higher basal rate of tachyzoite-to-bradyzoite differentiation. 3-Isobutyl-1-methylxanthine (IBMX treatment, which elevates cAMP levels, maintained wild-type parasites as tachyzoites under bradyzoite induction culture conditions (pH 8.2/low CO2, whereas the Δpkac3 mutant failed to respond to the treatment. This suggests that TgPKAc3 is the factor responsible for the cAMP-dependent tachyzoite maintenance. In addition, the Δpkac3 mutant had a defect in the production of brain cysts in vivo, suggesting that a substrate of TgPKAc3 is probably involved in the persistence of this parasite in the intermediate host animals.

  5. Latex-protein complexes from an acute phase recombinant antigen of Toxoplasma gondii for the diagnosis of recently acquired toxoplasmosis.

    Science.gov (United States)

    Peretti, Leandro E; Gonzalez, Verónica D G; Marcipar, Iván S; Gugliotta, Luis M

    2014-08-01

    The synthesis and characterization of latex-protein complexes (LPC), from the acute phase recombinant antigen P35 (P35Ag) of Toxoplasma gondii and "core-shell" carboxylated or polystyrene (PS) latexes (of different sizes and charge densities) are considered, with the aim of producing immunoagglutination reagents able to detect recently acquired toxoplasmosis. Physical adsorption (PA) and chemical coupling (CC) of P35Ag onto latex particles at different pH were investigated. Greater amounts of adsorbed protein were obtained on PS latexes than on carboxylated latexes, indicating that hydrophobic forces govern the interactions between the protein and the particle surface. In the CC experiments, the highest amount of bound protein was obtained at pH 6, near the isoelectric point of the protein (IP=6.27). At this pH, it decreased both the repulsion between particle surface and protein, and the repulsion between neighboring molecules. The LPC were characterized and the antigenicity of the P35Ag protein coupled on the particles surface was evaluated by Enzyme-Linked ImmunoSorbent Assay (ELISA). Results from ELISA showed that the P35Ag coupled to the latex particles surface was not affected during the particles sensitization by PA and CC and the produced LPC were able to recognize specific anti-P35Ag antibodies present in the acute phase of the disease. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Toxoplasma gondii autophagy-related protein ATG9 is crucial for the survival of parasites in their host.

    Science.gov (United States)

    Nguyen, Hoa Mai; El Hajj, Hiba; El Hajj, Rana; Tawil, Nadim; Berry, Laurence; Lebrun, Maryse; Bordat, Yann; Besteiro, Sébastien

    2017-06-01

    Autophagy is a conserved, life-promoting, catabolic process involved in the recycling of nonessential cellular components in response to stress. The parasite Toxoplasma gondii is an early-diverging eukaryote in which part of the autophagy machinery is not exclusively involved in a catabolic process but instead has been repurposed for an original function in organelle inheritance during cell division. This function, depending essentially on protein TgATG8 and its membrane conjugation system, is crucial for parasite survival and prevented an in depth study of autophagy in the mutants generated so far in Toxoplasma. Thus, in order to decipher the primary function of canonical autophagy in the parasites, we generated a cell line deficient for TgATG9, a protein thought to be involved in the early steps of the autophagy process. Although the protein proved to be dispensable for the development of these obligate intracellular parasites in vitro, the absence of TgATG9 led to a reduced ability to sustain prolonged extracellular stress. Importantly, depletion of the protein significantly reduced parasites survival in macrophages and markedly attenuated their virulence in mice. Altogether, this shows TgATG9 is important for the fate of Toxoplasma in immune cells and contributes to the overall virulence of the parasite, possibly through an involvement in a canonical autophagy pathway. © 2016 John Wiley & Sons Ltd.

  7. Theoretical investigation on structural, functional and epitope of a 12 kDa excretory-secretory protein from Toxoplasma gondii

    Directory of Open Access Journals (Sweden)

    Tommy Yap Boon Wooi

    2012-11-01

    Full Text Available Abstract Background Toxoplasma gondii is an intracellular coccidian parasite that causes toxoplasmosis. It was estimated that more than one third of the world population is infected by T. gondii, and the disease is critical in fetuses and immunosuppressed patients. Thus, early detection is crucial for disease diagnosis and therapy. However, the current available toxoplasmosis diagnostic tests vary in their accuracy and the better ones are costly. Results An earlier published work discovered a highly antigenic 12 kDa excretory-secretory (ES protein of T. gondii which may potentially be used for the development of an antigen detection test for toxoplasmosis. However, the three-dimensional structure of the protein is unknown. Since epitope identification is important prior to designing of a specific antibody for an antigen-detection based diagnostic test, the structural elucidation of this protein is essential. In this study, we constructed a three dimensional model of the 12 kDa ES protein. The built structure possesses a thioredoxin backbone which consists of four α-helices flanking five β-strands at the center. Three potential epitopes (6–8 residues which can be combined into one “single” epitope have been identified from the built structure as the most potential antibody binding site. Conclusion Together with specific antibody design, this work could contribute towards future development of an antigen detection test for toxoplasmosis.

  8. Export of a Toxoplasma gondii rhoptry neck protein complex at the host cell membrane to form the moving junction during invasion.

    Directory of Open Access Journals (Sweden)

    Sébastien Besteiro

    2009-02-01

    Full Text Available One of the most conserved features of the invasion process in Apicomplexa parasites is the formation of a moving junction (MJ between the apex of the parasite and the host cell membrane that moves along the parasite and serves as support to propel it inside the host cell. The MJ was, up to a recent period, completely unknown at the molecular level. Recently, proteins originated from two distinct post-Golgi specialised secretory organelles, the micronemes (for AMA1 and the neck of the rhoptries (for RON2/RON4/RON5 proteins, have been shown to form a complex. AMA1 and RON4 in particular, have been localised to the MJ during invasion. Using biochemical approaches, we have identified RON8 as an additional member of the complex. We also demonstrated that all RON proteins are present at the MJ during invasion. Using metabolic labelling and immunoprecipitation, we showed that RON2 and AMA1 were able to interact in the absence of the other members. We also discovered that all MJ proteins are subjected to proteolytic maturation during trafficking to their respective organelles and that they could associate as non-mature forms in vitro. Finally, whereas AMA1 has previously been shown to be inserted into the parasite membrane upon secretion, we demonstrated, using differential permeabilization and loading of RON-specific antibodies into the host cell, that the RON complex is targeted to the host cell membrane, where RON4/5/8 remain associated with the cytoplasmic face. Globally, these results point toward a model of MJ organization where the parasite would be secreting and inserting interacting components on either side of the MJ, both at the host and at its own plasma membranes.

  9. Toxoplasma gondii

    Science.gov (United States)

    Jones, Jeffrey L; Kruszon-Moran, Deanna; Elder, Scott; Rivera, Hilda N; Press, Cindy; Montoya, Jose G; McQuillan, Geraldine M

    2018-02-01

    Toxoplasma gondii can cause severe neurologic and ocular disease when transmitted congenitally and in immunosuppressed persons. Sera collected in the National Health and Nutrition Examination Survey 2011 through 2014 in 13,507 persons ≥ 6 years old were tested for T. gondii immunoglobulin (Ig) G and IgM antibodies, and in those both IgG and IgM antibody positive, for IgG avidity. Overall, 11.14% (95% confidence limits [CL] 9.88%, 12.51%) were seropositive for T. gondii IgG antibody (age-adjusted seroprevalence 10.42% [95% CL 9.19%, 11.76%]); in women aged 15-44 years, the age-adjusted T. gondii IgG seroprevalence was 7.50% (95% CL 6.00%, 9.25%). In multivariable analysis, risk for IgG seropositivity increased with age and was higher in males; persons living below the poverty level; persons with ≤ a high school education compared with those with > a high school education; and non-Hispanic black, Mexican American, and foreign born non-Hispanic white persons compared with U.S.-born non-Hispanic white persons. Overall, 1.16% (95% CL 0.94%, 1.42%) were T. gondii IgM antibody positive and 0.71%, (95% CL 0.54%, 0.92%) were both IgM and IgG antibody positive. In multivariable analysis, the significant risk factors for being both IgM and IgG positive were older age, crowding, and non-U.S. birth origin compared with U.S.-born persons. Among those positive for both IgM and IgG antibody, almost all had high avidity (all women aged 15-44 years had high avidity). Toxoplasma gondii antibody prevalence remains relatively low in the United States, although it is higher in non-U.S.-born persons, males, and some minority and socioeconomically disadvantaged groups.

  10. Disruption of the Toxoplasma gondii parasitophorous vacuole by IFNgamma-inducible immunity-related GTPases (IRG proteins triggers necrotic cell death.

    Directory of Open Access Journals (Sweden)

    Yang O Zhao

    2009-02-01

    Full Text Available Toxoplasma gondii is a natural intracellular protozoal pathogen of mice and other small mammals. After infection, the parasite replicates freely in many cell types (tachyzoite stage before undergoing a phase transition and encysting in brain and muscle (bradyzoite stage. In the mouse, early immune resistance to the tachyzoite stage is mediated by the family of interferon-inducible immunity-related GTPases (IRG proteins, but little is known of the nature of this resistance. We reported earlier that IRG proteins accumulate on intracellular vacuoles containing the pathogen, and that the vacuolar membrane subsequently ruptures. In this report, live-cell imaging microscopy has been used to follow this process and its consequences in real time. We show that the rupture of the vacuole is inevitably followed by death of the intracellular parasite, shown by its permeability to cytosolic protein markers. Death of the parasite is followed by the death of the infected cell. The death of the cell has features of pyronecrosis, including membrane permeabilisation and release of the inflammatory protein, HMGB1, but caspase-1 cleavage is not detected. This sequence of events occurs on a large scale only following infection of IFNgamma-induced cells with an avirulent strain of T. gondii, and is reduced by expression of a dominant negative mutant IRG protein. Cells infected by virulent strains rarely undergo necrosis. We did not find autophagy to play any role in the key steps leading to the death of the parasite. We conclude that IRG proteins resist infection by avirulent T. gondii by a novel mechanism involving disruption of the vacuolar membrane, which in turn ultimately leads to the necrotic death of the infected cell.

  11. The Ultrastructural Effects of Sulfachloropyrazine on Toxoplasma Gondii Tachyzoites

    Directory of Open Access Journals (Sweden)

    YB Zeng

    2013-03-01

    Full Text Available Background: Toxoplasmosis is one of the most common parasitic infections of humans and other mammals. This study was aimed to understand the mechanism of action of veterinary medicine-sulfachlo­ropyrazine (SPZ, 99.97% against Toxoplasma gondii.Methods: T. gondii tachyzoites were soaked in PBS (as a control or SPZ (250 mg/mL for 2 h at 37 °C. After being processed, any ultrastructural changes of the tachyzoites that had occurred were observed by Scanning Electron Microscopy (SEM and Transmission Electron Microscopy (TEM.Results: The tachyzoites from control groups with a uniform size had a smooth surface and intact cell or nuclear membranes. In addition, an oval-shaped nucleus, conoids and micronemes were also observed. By contrast, many parasites from the SPZ-treated groups were detrimentally affected by the treatment. Some appeared to be of the vacuolization in their cytoplasm, with the substantial reduc­tion in the number of dense granules and the blur of some organelles.Conclusion: The morphology and ultrastructure of tachyzoites can be affected significantly by SPZ, which might kill the parasite by inhibiting its energy metabolism, inducing apoptosis and damaging its structure. The study provides an experimental basis for further study on the mechanism of SPZ against T. gondii.

  12. The Ultrastructural Effects of Sulfachloropyrazine on Toxoplasma gondii Tachyzoites.

    Science.gov (United States)

    Zeng, Yb; Dong, H; Han, Hy; Jiang, Ll; Zhao, Qp; Zhu, Sh; Ma, Wj; Cheng, J; Huang, B

    2013-01-01

    Toxoplasmosis is one of the most common parasitic infections of humans and other mammals. This study was aimed to understand the mechanism of action of veterinary medicine-sulfachloropyrazine (SPZ, 99.97%) against Toxoplasma gondii. T. gondii tachyzoites were soaked in PBS (as a control) or SPZ (250 mg/mL) for 2 h at 37 °C. After being processed, any ultrastructural changes of the tachyzoites that had occurred were observed by Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). The tachyzoites from control groups with a uniform size had a smooth surface and intact cell or nuclear membranes. In addition, an oval-shaped nucleus, conoids and micronemes were also observed. By contrast, many parasites from the SPZ-treated groups were detrimentally affected by the treatment. Some appeared to be of the vacuolization in their cytoplasm, with the substantial reduction in the number of dense granules and the blur of some organelles. The morphology and ultrastructure of tachyzoites can be affected significantly by SPZ, which might kill the parasite by inhibiting its energy metabolism, inducing apoptosis and damaging its structure. The study provides an experimental basis for further study on the mechanism of SPZ against T. gondii.

  13. A Toxoplasma gondii protein with homology to intracellular type Na{sup +}/H{sup +} exchangers is important for osmoregulation and invasion

    Energy Technology Data Exchange (ETDEWEB)

    Francia, Maria E.; Wicher, Sarah [Department of Biological Sciences, University of Idaho, Life Sciences South Room 142, Moscow, ID 83844 (United States); Pace, Douglas A. [Center for Tropical and Emerging Global Diseases and Department of Cellular Biology University of Georgia, Athens, GA 30602 (United States); Sullivan, Jack [Department of Biological Sciences, University of Idaho, Life Sciences South Room 142, Moscow, ID 83844 (United States); Moreno, Silvia N.J. [Center for Tropical and Emerging Global Diseases and Department of Cellular Biology University of Georgia, Athens, GA 30602 (United States); Arrizabalaga, Gustavo, E-mail: gustavo@uidaho.edu [Department of Biological Sciences, University of Idaho, Life Sciences South Room 142, Moscow, ID 83844 (United States)

    2011-06-10

    The obligate intracellular parasite Toxoplasma gondii is exposed to a variety of physiological conditions while propagating in an infected organism. The mechanisms by which Toxoplasma overcomes these dramatic changes in its environment are not known. In yeast and plants, ion detoxification and osmotic regulation are controlled by vacuolar compartments. A novel compartment named the plant-like vacuole or vacuolar compartment (PLV/VAC) has recently been described in T.gondii, which could potentially protect extracellular tachyzoites against salt and other ionic stresses. Here, we report the molecular characterization of the vacuolar type Na{sup +}/H{sup +} exchanger in T. gondii, TgNHE3, and its co-localization with the PLV/VAC proton-pyrophosphatase (TgVP1). We have created a TgNHE3 knockout strain, which is more sensitive to hyperosmotic shock and toxic levels of sodium, possesses a higher intracellular Ca{sup 2+} concentration [Ca{sup 2+}]{sub i}, and exhibits a reduced host invasion efficiency. The defect in invasion correlates with a measurable reduction in the secretion of the adhesin TgMIC2. Overall, our results suggest that the PLV/VAC has functions analogous to those of the vacuolar compartments of plants and yeasts, providing the parasite with a mechanism to resist ionic fluctuations and, potentially, regulate protein trafficking.

  14. Evaluation of protective immune responses induced by DNA vaccines encoding Toxoplasma gondii surface antigen 1 (SAG1) and 14-3-3 protein in BALB/c mice.

    Science.gov (United States)

    Meng, Min; He, Shenyi; Zhao, Guanghui; Bai, Yang; Zhou, Huaiyu; Cong, Hua; Lu, Gang; Zhao, Qunli; Zhu, Xing-Quan

    2012-11-26

    Toxoplasmosis, caused by an obligate intracellular protozoan parasite Toxoplasma gondii, has been a serious clinical and veterinary problem. Effective DNA vaccines against T. gondii can prevent and control the spread of toxoplasmosis, which is important for both human health and the farming industry. The T. gondii 14-3-3 protein has been proved to be antigenic and immunogenic and was a potential vaccine candidate against toxoplasmosis. In this study, we evaluated the immune responses induced by recombinant plasmids encoding T. gondii surface antigen 1 (SAG1) and 14-3-3 protein by immunizing BALB/c mice intramuscularly. In the present study, BALB/c mice were randomly divided into five groups, including three experimental groups (pSAG1, p14-3-3 and pSAG1/14-3-3) and two control groups (PBS and pBudCE4.1), and were immunized intramuscularly three times. The levels of IgG antibodies and cytokine production in mouse sera were determined by enzyme-linked immunosorbent assays (ELISA). Two weeks after the last immunization, all mice were challenged intraperitoneally (i.p.) with 1×10(4) tachyzoites of T. gondii and the survival time of mice was observed and recorded every day. Mice vaccinated with pSAG1, p14-3-3 or pSAG1/14-3-3 developed high levels of IgG2a and gamma interferon (IFN-γ) and low levels of interleukin-4 (IL-4) and interleukin-10 (IL-10) compared to control groups (PBS or pBudCE4.1), which suggested a modulated Th1 type immune response (Pmice in experimental groups was longer than control groups (Pmice and was a novel DNA vaccine candidate against toxoplasmosis, and the immune protective efficacy elicited by SAG1 gene was also demonstrated. Our results also showed multi-gene vaccine significantly enhanced immune responses and protective efficacy and was superior to the single-gene vaccine.

  15. Moving towards improved vaccines for Toxoplasma gondii.

    Science.gov (United States)

    Li, Yawen; Zhou, Huaiyu

    2018-03-01

    Toxoplasma gondii is an intracellular parasitic protozoan that infects almost all warm-blooded animals and humans, resulting in threats to public health and economic losses. Despite continuous research efforts, there are still very few effective strategies against toxoplasmosis. In the past few years, numerous vaccination experiments have been performed to control T. gondii infection. Areas covered: In this review, the authors summarize the development of T. gondii vaccines with proper adjuvants, ranging from live or live-attenuated vaccines to protein vaccines, DNA vaccines, epitope vaccines and novel vaccines. They also highlight the challenges involved in the development of T. gondii vaccines, including specific impediments and shortcomings. Expert opinion: Moving towards the development of effective vaccines against T. gondii is not only a tedious mission but also a difficult challenge. Future studies should consider new approaches and strategies for vaccine development, particularly novel vaccines and genetic adjuvants, as well as optimizing immunization protocols and evaluation criteria.

  16. CCp5A protein from Toxoplasma gondii as a serological marker of oocyst-driven infections in humans and domestic animals.

    Directory of Open Access Journals (Sweden)

    Silas Silva Santana

    2015-11-01

    Full Text Available Considering that the current immunoassays are not able to distinguish the infective forms that cause Toxoplasma gondii infection, the present study was carried out to evaluate the reactivity of two recombinant proteins (CCp5A and OWP1 from oocyst/sporozoite, in order to differentiate infections occurring by ingestion of oocysts or tissue cysts. The reactivity of the recombinant proteins was assessed against panels of serum samples from animals (chickens, pigs and mice that were naturally or experimentally infected by different infective stages of the parasite. Also, we tested sera from humans who have been infected by oocysts during a well-characterized toxoplasmosis outbreak, as well as sera from pregnant women tested IgM+/IgG+ for T. gondii, which source of infection was unknown. Only the sporozoite-specific CCp5A protein was able to differentiate the parasite stage that infected chickens, pigs and mice, with specific reactivity for oocyst-infected animals. Furthermore, the CCp5A showed preferential reactivity for recent infection by oocyst/sporozoite in pigs and mice. In humans, CCp5A showed higher reactivity with serum samples from the outbreak, compared with serum from pregnant women. Altogether, these findings demonstrate the usefulness of the CCp5A protein as a new tool to identify the parasite state of T. gondii infection, allowing its application for diagnosis and epidemiological investigations in animals and humans. The identification of parasite infective stage can help to design effective strategies to minimize severe complications in immunocompromised people and, particularly, in pregnant women to prevent congenital infection.

  17. Towards vaccine against toxoplasmosis: evaluation of the immunogenic and protective activity of recombinant ROP5 and ROP18 Toxoplasma gondii proteins.

    Science.gov (United States)

    Grzybowski, Marcin M; Dziadek, Bożena; Gatkowska, Justyna M; Dzitko, Katarzyna; Długońska, Henryka

    2015-12-01

    Toxoplasmosis is one of the most common parasitic infections worldwide. An effective vaccine against human and animal toxoplasmosis is still needed to control this parasitosis. The polymorphic rhoptry proteins, ROP5 and ROP18, secreted by Toxoplasma gondii during the invasion of the host cell have been recently considered as promising vaccine antigens, as they appear to be the major determinants of T. gondii virulence in mice. The goal of this study was to evaluate their immunogenic and immunoprotective activity after their administration (separately or both recombinant proteins together) with the poly I:C as an adjuvant. Immunization of BALB/c and C3H/HeOuJ mice generated both cellular and humoral specific immune responses with some predominance of IgG1 antibodies. The spleen cells derived from vaccinated animals reacted to the parasite's native antigens. Furthermore, the immunization led to a partial protection against acute and chronic toxoplasmosis. These findings confirm the previous assumptions about ROP5 and ROP18 antigens as valuable components of a subunit vaccine against toxoplasmosis.

  18. Loss of a doublecortin (DCX)-domain protein causes structural defects in a tubulin-based organelle of Toxoplasma gondii and impairs host-cell invasion

    Science.gov (United States)

    Nagayasu, Eiji; Hwang, Yu-Chen; Liu, Jun; Murray, John M.; Hu, Ke

    2017-01-01

    The ∼6000 species in phylum Apicomplexa are single-celled obligate intracellular parasites. Their defining characteristic is the apical complex—membranous and cytoskeletal elements at the apical end of the cell that participate in host-cell invasion. The apical complex of Toxoplasma gondii and some other apicomplexans includes a cone-shaped assembly, the conoid, which in T. gondii comprises 14 spirally arranged fibers that are nontubular polymers of tubulin. The tubulin dimers of the conoid fibers make canonical microtubules elsewhere in the same cell, suggesting that nontubulin protein dictates their special arrangement in the conoid fibers. One candidate for this role is TgDCX, which has a doublecortin (DCX) domain and a TPPP/P25-α domain, both of which are known modulators of tubulin polymer structure. Loss of TgDCX radically disrupts the structure of the conoid, severely impairs host-cell invasion, and slows growth. Both the conoid structural defects and the impaired invasion of TgDCX-null parasites are corrected by reintroduction of a TgDCX coding sequence. The nontubular polymeric form of tubulin found in the conoid is not found in the host cell, suggesting that TgDCX may be an attractive target for new parasite-specific chemotherapeutic agents. PMID:27932494

  19. Evaluation of Protective Immune Responses Induced by Recombinant TrxLp and ENO2 Proteins against Toxoplasma gondii Infection in BALB/c Mice

    Directory of Open Access Journals (Sweden)

    Meng Wang

    2016-01-01

    Full Text Available Toxoplasma gondii is an obligate intracellular parasitic protozoan that can infect almost all species of warm-blooded animals. As any chemical-based drugs could not act against the tissue cyst stage of T. gondii, vaccination may be one of the ideal control strategies. In the present study, two new vaccine candidates, named TgENO2 and TgTrxLp, were purified from Escherichia coli with pET-30a(+ expression system and then were injected into BALB/c mice to evaluate the protective efficacy against acute and chronic toxoplasmosis. The results showed that both the recombinant proteins, either alone or in combination, could elicit strong humoral and cellular immune responses with a higher level of IgG antibodies, IFN-γ, IL-2, CD4+, and CD8+ T cells as compared to those in mice from control groups. After acute challenge with tachyzoites of the GJS strain, mice immunized with rTgTrxLp (8±2.77 d, rTgENO2 (7.4±1.81 d, and rTgTrxLp + rTgENO2 (8.38±4.57 d proteins showed significantly longer survival time than those that received Freund’s adjuvant (6.78±2.08 d and PBS (6.38±4.65 d (χ2 = 9.687, df = 4, P=0.046. The protective immunity of rTgTrxLp, rTgENO2, and rTgTrxLp + rTgENO2 proteins against chronic T. gondii infection showed 69.77%, 58.14%, and 20.93% brain cyst reduction as compared to mice that received PBS. The present study suggested that both TgENO2 and TgTrxLp were potential candidates for the development of multicomponent vaccines against toxoplasmosis.

  20. Rhoptry Proteins ROP5 and ROP18 Are Major Murine Virulence Factors in Genetically Divergent South American Strains of Toxoplasma gondii.

    Directory of Open Access Journals (Sweden)

    Michael S Behnke

    2015-08-01

    Full Text Available Toxoplasma gondii has evolved a number of strategies to evade immune responses in its many hosts. Previous genetic mapping of crosses between clonal type 1, 2, and 3 strains of T. gondii, which are prevalent in Europe and North America, identified two rhoptry proteins, ROP5 and ROP18, that function together to block innate immune mechanisms activated by interferon gamma (IFNg in murine hosts. However, the contribution of these and other virulence factors in more genetically divergent South American strains is unknown. Here we utilized a cross between the intermediately virulent North American type 2 ME49 strain and the highly virulent South American type 10 VAND strain to map the genetic basis for differences in virulence in the mouse. Quantitative trait locus (QTL analysis of this new cross identified one peak that spanned the ROP5 locus on chromosome XII. CRISPR-Cas9 mediated deletion of all copies of ROP5 in the VAND strain rendered it avirulent and complementation confirmed that ROP5 is the major virulence factor accounting for differences between type 2 and type 10 strains. To extend these observations to other virulent South American strains representing distinct genetic populations, we knocked out ROP5 in type 8 TgCtBr5 and type 4 TgCtBr18 strains, resulting in complete loss of virulence in both backgrounds. Consistent with this, polymorphisms that show strong signatures of positive selection in ROP5 were shown to correspond to regions known to interface with host immunity factors. Because ROP5 and ROP18 function together to resist innate immune mechanisms, and a significant interaction between them was identified in a two-locus scan, we also assessed the role of ROP18 in the virulence of South American strains. Deletion of ROP18 in South American type 4, 8, and 10 strains resulted in complete attenuation in contrast to a partial loss of virulence seen for ROP18 knockouts in previously described type 1 parasites. These data show that ROP5

  1. Immunodiagnosis and molecular validation of Toxoplasma gondii-recombinant dense granular (GRA) 7 protein for the detection of toxoplasmosis in patients with cancer.

    Science.gov (United States)

    Arab-Mazar, Zahra; Fallahi, Shirzad; Koochaki, Ameneh; Haghighi, Ali; Seyyed Tabaei, Seyyed Javad

    2016-02-01

    Serological assays for the diagnosis of toxoplasmosis mostly rely on the tachyzoite specific antigens of Toxoplasma gondii, which are difficult to produce by conventional methods. The aim of this study was to clone and express of GRA7 protein of T. gondii and evaluate its potential for immunodiagnosis of toxoplasmosis in cancer patients. As well as validate the results using a new molecular assay, LAMP technique. The GRA7 gene was successfully cloned, expressed and purified by affinity chromatography and the production was evaluated by SDS PAGE, dot blot and western blot analyses. The rGRA7 was used for developing an ELISA based on the rGRA7 using sera from patients with toxoplasmosis and healthy controls. Furthermore, 50 serum samples from leukemic children infected with toxoplasmosis and 50 seronegative controls were included to evaluate the sensitivity and specificity of rGRA7 based ELISA. Finally, the LAMP technique was used to assess the accuracy and validity of the results obtained by rGRA7 based ELISA. The consistency of the results of two tests was determined by using the Kappa coefficient of agreement. The rGRA7 showed higher and optimum immunoreactivity with 1:100 dilution of serum from Toxoplasma infected patients. The sensitivity and specificity of test were calculated as 92 and 94%, respectively. According to the Kappa coefficient of agreement, there was a significant conformance between the results obtained by ELISA based on the rGRA7 and the results of LAMP technique (≈96%, Ptoxoplasmosis in patients including patients with cancer. Copyright © 2015. Published by Elsevier GmbH.

  2. Calcium Entry in Toxoplasma gondii and Its Enhancing Effect of Invasion-linked Traits*

    Science.gov (United States)

    Pace, Douglas A.; McKnight, Ciara A.; Liu, Jing; Jimenez, Veronica; Moreno, Silvia N. J.

    2014-01-01

    During invasion and egress from their host cells, Apicomplexan parasites face sharp changes in the surrounding calcium ion (Ca2+) concentration. Our work with Toxoplasma gondii provides evidence for Ca2+ influx from the extracellular milieu leading to cytosolic Ca2+ increase and enhancement of virulence traits, such as gliding motility, conoid extrusion, microneme secretion, and host cell invasion. Assays of Mn2+ and Ba2+ uptake do not support a canonical store-regulated Ca2+ entry mechanism. Ca2+ entry was blocked by the L-type Ca2+ channel inhibitor nifedipine and stimulated by the increase in cytosolic Ca2+ and by the specific L-type Ca2+ channel agonist Bay K-8644. Our results demonstrate that Ca2+ entry is critical for parasite virulence. We propose a regulated Ca2+ entry mechanism activated by cytosolic Ca2+ that has an enhancing effect on invasion-linked traits. PMID:24867952

  3. Identification of novel proteins in Neospora caninum using an organelle purification and monoclonal antibody approach.

    Directory of Open Access Journals (Sweden)

    Catherine S Sohn

    2011-04-01

    Full Text Available Neospora caninum is an important veterinary pathogen that causes abortion in cattle and neuromuscular disease in dogs. Neospora has also generated substantial interest because it is an extremely close relative of the human pathogen Toxoplasma gondii, yet does not appear to infect humans. While for Toxoplasma there are a wide array of molecular tools and reagents available for experimental investigation, relatively few reagents exist for Neospora. To investigate the unique biological features of this parasite and exploit the recent sequencing of its genome, we have used an organelle isolation and monoclonal antibody approach to identify novel organellar proteins and develop a wide array of probes for subcellular localization. We raised a panel of forty-six monoclonal antibodies that detect proteins from the rhoptries, micronemes, dense granules, inner membrane complex, apicoplast, mitochondrion and parasite surface. A subset of the proteins was identified by immunoprecipitation and mass spectrometry and reveal that we have identified and localized many of the key proteins involved in invasion and host interaction in Neospora. In addition, we identified novel secretory proteins not previously studied in any apicomplexan parasite. Thus, this organellar monoclonal antibody approach not only greatly enhances the tools available for Neospora cell biology, but also identifies novel components of the unique biological characteristics of this important veterinary pathogen.

  4. Identification of Novel Proteins in Neospora caninum Using an Organelle Purification and Monoclonal Antibody Approach

    Science.gov (United States)

    Sohn, Catherine S.; Cheng, Tim T.; Drummond, Michael L.; Peng, Eric D.; Vermont, Sarah J.; Xia, Dong; Cheng, Stephen J.; Wastling, Jonathan M.; Bradley, Peter J.

    2011-01-01

    Neospora caninum is an important veterinary pathogen that causes abortion in cattle and neuromuscular disease in dogs. Neospora has also generated substantial interest because it is an extremely close relative of the human pathogen Toxoplasma gondii, yet does not appear to infect humans. While for Toxoplasma there are a wide array of molecular tools and reagents available for experimental investigation, relatively few reagents exist for Neospora. To investigate the unique biological features of this parasite and exploit the recent sequencing of its genome, we have used an organelle isolation and monoclonal antibody approach to identify novel organellar proteins and develop a wide array of probes for subcellular localization. We raised a panel of forty-six monoclonal antibodies that detect proteins from the rhoptries, micronemes, dense granules, inner membrane complex, apicoplast, mitochondrion and parasite surface. A subset of the proteins was identified by immunoprecipitation and mass spectrometry and reveal that we have identified and localized many of the key proteins involved in invasion and host interaction in Neospora. In addition, we identified novel secretory proteins not previously studied in any apicomplexan parasite. Thus, this organellar monoclonal antibody approach not only greatly enhances the tools available for Neospora cell biology, but also identifies novel components of the unique biological characteristics of this important veterinary pathogen. PMID:21483743

  5. Long-Term Protective Immune Response Elicited by Vaccination with an Expression Genomic Library of Toxoplasma gondii

    OpenAIRE

    Fachado, Alberto; Rodriguez, Alexandro; Molina, Judith; Silvério, Jaline C.; Marino, Ana P. M. P.; Pinto, Luzia M. O.; Angel, Sergio O.; Infante, Juan F.; Traub-Cseko, Yara; Amendoeira, Regina R.; Lannes-Vieira, Joseli

    2003-01-01

    Immunization of BALB/c mice with an expression genomic library of Toxoplasma gondii induces a Th1-type immune response, with recognition of several T. gondii proteins (21 to 117 kDa) and long-term protective immunity against a lethal challenge. These results support further investigations to achieve a multicomponent anti-T. gondii DNA vaccine.

  6. Evaluation of Toxoplasma gondii as a live vaccine vector in susceptible and resistant hosts

    Directory of Open Access Journals (Sweden)

    Wang Heng

    2011-08-01

    Full Text Available Abstract Background Toxoplasma gondii has been shown to trigger strong cellular immune responses to heterologous antigens expressed by the parasite in the inbred mouse model 1. We studied the immune response induced by T. gondii as an effective vaccine vector in chickens and rabbits. Results T. gondii RH strain was engineered to express the yellow fluorescent protein (YFP in the cytoplasm. A subcutaneous injection of the transgenic T. gondii YFP in chickens afforded partial protection against the infection of transgenic E. tenella YFP. T. gondii YFP induced low levels of antibodies to YFP in chickens, suggesting that YFP specific cellular immune response was probably responsible for the protective immunity against E. tenella YFP infection. The measurement of T-cell response and IFN-γ production further confirmed that YFP specific Th1 mediated immune response was induced by T. gondii YFP in immunized chickens. The transgenic T. gondii stimulated significantly higher YFP specific IgG titers in rabbits than in chickens, suggesting greater immunogenicity in a T. gondii susceptible species than in a resistant species. Priming with T. gondii YFP and boosting with the recombinant YFP can induce a strong anti-YFP antibody response in both animal species. Conclusions Our findings suggest that T. gondii can be used as an effective vaccine vector and future research should focus on exploring avirulent no cyst-forming strains of T. gondii as a live vaccine vector in animals.

  7. RecNcMIC3-1-R is a microneme- and rhoptry-based chimeric antigen that protects against acute neosporosis and limits cerebral parasite load in the mouse model for Neospora caninum infection.

    Science.gov (United States)

    Monney, Thierry; Rütti, David; Schorer, Michelle; Debache, Karim; Grandgirard, Denis; Leib, Stephen L; Hemphill, Andrew

    2011-09-16

    In order to achieve host cell entry, the apicomplexan parasite Neospora caninum relies on the contents of distinct organelles, named micronemes, rhoptries and dense granules, which are secreted at defined timepoints during and after host cell entry. It was shown previously that a vaccine composed of a mixture of three recombinant antigens, corresponding to the two microneme antigens NcMIC1 and NcMIC3 and the rhoptry protein NcROP2, prevented disease and limited cerebral infection and transplacental transmission in mice. In this study, we selected predicted immunogenic domains of each of these proteins and created four different chimeric antigens, with the respective domains incorporated into these chimers in different orders. Following vaccination, mice were challenged intraperitoneally with 2 × 10(6)N. caninum tachzyoites and were then carefully monitored for clinical symptoms during 4 weeks post-infection. Of the four chimeric antigens, only recNcMIC3-1-R provided complete protection against disease with 100% survivors, compared to 40-80% of survivors in the other groups. Serology did not show any clear differences in total IgG, IgG1 and IgG2a levels between the different treatment groups. Vaccination with all four chimeric variants generated an IL-4 biased cytokine expression, which then shifted to an IFN-γ-dominated response following experimental infection. Sera of recNcMIC3-1-R vaccinated mice reacted with each individual recombinant antigen, as well as with three distinct bands in Neospora extracts with similar Mr as NcMIC1, NcMIC3 and NcROP2, and exhibited distinct apical labeling in tachyzoites. These results suggest that recNcMIC3-1-R is an interesting chimeric vaccine candidate and should be followed up in subsequent studies in a fetal infection model. Copyright © 2011 Elsevier Ltd. All rights reserved.

  8. Taxonomy Icon Data: Toxoplasma gondii [Taxonomy Icon

    Lifescience Database Archive (English)

    Full Text Available Toxoplasma gondii Toxoplasma gondii Toxoplasma_gondii_L.png Toxoplasma_gondii_NL.png Toxoplasma..._gondii_S.png Toxoplasma_gondii_NS.png http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Toxoplasma...+gondii&t=L http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Toxoplasma+gondii&t=NL http://biosciencedbc.j...p/taxonomy_icon/icon.cgi?i=Toxoplasma+gondii&t=S http://biosciencedbc.jp/taxonomy..._icon/icon.cgi?i=Toxoplasma+gondii&t=NS http://togodb.biosciencedbc.jp/togodb/view/taxonomy_icon_comment_en?species_id=113 ...

  9. The Rhoptry Proteins ROP18 and ROP5 Mediate Toxoplasma gondii Evasion of the Murine, But Not the Human, Interferon-Gamma Response

    Science.gov (United States)

    Niedelman, Wendy; Gold, Daniel A.; Rosowski, Emily E.; Sprokholt, Joris K.; Lim, Daniel; Farid Arenas, Ailan; Melo, Mariane B.; Spooner, Eric; Yaffe, Michael B.; Saeij, Jeroen P. J.

    2012-01-01

    The obligate intracellular parasite Toxoplasma gondii secretes effector proteins into the host cell that manipulate the immune response allowing it to establish a chronic infection. Crosses between the types I, II and III strains, which are prevalent in North America and Europe, have identified several secreted effectors that determine strain differences in mouse virulence. The polymorphic rhoptry protein kinase ROP18 was recently shown to determine the difference in virulence between type I and III strains by phosphorylating and inactivating the interferon-γ (IFNγ)-induced immunity-related GTPases (IRGs) that promote killing by disrupting the parasitophorous vacuole membrane (PVM) in murine cells. The polymorphic pseudokinase ROP5 determines strain differences in virulence through an unknown mechanism. Here we report that ROP18 can only inhibit accumulation of the IRGs on the PVM of strains that also express virulent ROP5 alleles. In contrast, specific ROP5 alleles can reduce IRG coating even in the absence of ROP18 expression and can directly interact with one or more IRGs. We further show that the allelic combination of ROP18 and ROP5 also determines IRG evasion and virulence of strains belonging to other lineages besides types I, II and III. However, neither ROP18 nor ROP5 markedly affect survival in IFNγ-activated human cells, which lack the multitude of IRGs present in murine cells. These findings suggest that ROP18 and ROP5 have specifically evolved to block the IRGs and are unlikely to have effects in species that do not have the IRG system, such as humans. PMID:22761577

  10. Discrimination of potent inhibitor/span>s of Toxoplasma gondii enoyl-acyl carrier protein reductase by a thermal shift assay.

    Science.gov (United States)

    Afanador, Gustavo A; Muench, Stephen P; McPhillie, Martin; Fomovska, Alina; Schön, Arne; Zhou, Ying; Cheng, Gang; Stec, Jozef; Freundlich, Joel S; Shieh, Hong-Ming; Anderson, John W; Jacobus, David P; Fidock, David A; Kozikowski, Alan P; Fishwick, Colin W; Rice, David W; Freire, Ernesto; McLeod, Rima; Prigge, Sean T

    2013-12-23

    Many microbial pathogens rely on a type II fatty acid synthesis (FASII) pathway that is distinct from the type I pathway found in humans. Enoyl-acyl carrier protein reductase (ENR) is an essential FASII pathway enzyme and the target of a number of antimicrobial drug discovery efforts. The biocide triclosan is established as a potent inhibitor of ENR and has been the starting point for medicinal chemistry studies. We evaluated a series of triclosan analogues for their ability to inhibit the growth of Toxoplasma gondii, a pervasive human pathogen, and its ENR enzyme (TgENR). Several compounds that inhibited TgENR at low nanomolar concentrations were identified but could not be further differentiated because of the limited dynamic range of the TgENR activity assay. Thus, we adapted a thermal shift assay (TSA) to directly measure the dissociation constant (Kd) of the most potent inhibitor/span>s identified in this study as well as inhibitors from previous studies. Furthermore, the TSA allowed us to determine the mode of action of these compounds in the presence of the reduced nicotinamide adenine dinucleotide (NADH) or nicotinamide adenine dinucleotide (NAD⁺) cofactor. We found that all of the inhibitors bind to a TgENR-NAD⁺ complex but that they differed in their dependence on NAD⁺ concentration. Ultimately, we were able to identify compounds that bind to the TgENR-NAD⁺ complex in the low femtomolar range. This shows how TSA data combined with enzyme inhibition, parasite growth inhibition data, and ADMET predictions allow for better discrimination between potent ENR inhibitors for the future development of medicine.

  11. Ongenode gasten: Toxoplasma Gondii

    NARCIS (Netherlands)

    Verkleij, T.H.; Boer, P. de

    2016-01-01

    Vrijwel alle organismen, ook de mens, hebben last van parasieten: wormen, vlooien, luizen, teken. Toxoplasma gondii is wereldwijd één van de meest voorkomende parasitaire zoönosen. Vooral voor zwangere vrouwen kunnen de gevolgen groot zijn. Wat is het? En hoe is het te voorkomen?

  12. Detection of Toxoplasma gondii in chicken and soil of chicken farms in Nanjing region, China.

    Science.gov (United States)

    Liu, Xin-Chao; He, Yu; Han, Deng-Ge; Zhang, Zhen-Chao; Li, Ke; Wang, Shuai; Xu, Li-Xin; Yan, Ruo-Feng; Li, Xiang-Rui

    2017-05-09

    Soil is increasingly recognized as an important source in the transmission of Toxoplasma gondii (T. gondii). The aim of this study was to investigate the presence of T. gondii in the soil and to grasp the relationships between the contamination of soil and chicken infections. PCR method based on T. gondii-conserved gene internal transcribed spacer 1 (ITS-1) as target gene and ELISA method (sGRA8-ELISA) using the recombinant protein of shortened GRA8 gene of T. gondii as antigen were developed and applied. From April 2013 to March 2014, a total of 700 soil samples were collected at various sites located in thirty farms categorized as free range farm and scale farm in Nanjing, Jiangsu, China, in different seasons. Additionally, a total of 350 sera of chickens were collected from free range farms to determine the presence of antibodies against T. gondii using sGRA8-ELISA. The serological results showed that, antibodies were found in 194 of 250 (67.14%) samples from farms with T. gondii positive in soil and 41 of 100 samples from farms with T. gondii negative in soil (41.00%) (P chickens in the farm with soil contamination was higher than that with no soil contamination. The soil contamination might be an effective indicator of T. gondii infection in chickens.

  13. Genetic diversity among Toxoplasma gondii isolates from different ...

    African Journals Online (AJOL)

    Yomi

    2012-03-27

    Mar 27, 2012 ... could represent a good vaccine candidate against toxoplasmosis. Key words: Toxoplasma gondii, toxoplasmosis, rhpotry protein 13 (ROP13), sequence ... GCTCTAGATCACAATAGCCTCAAGGAATTC-3′. PCR reactions. (25 µl) were performed in a mixture with 2.5 mM of MgCl2, 2.5 µM of each primer, 2.5 ...

  14. Sequence Variation in Toxoplasma gondii rop17 Gene among Strains from Different Hosts and Geographical Locations

    Directory of Open Access Journals (Sweden)

    Nian-Zhang Zhang

    2014-01-01

    Full Text Available Genetic diversity of T. gondii is a concern of many studies, due to the biological and epidemiological diversity of this parasite. The present study examined sequence variation in rhoptry protein 17 (ROP17 gene among T. gondii isolates from different hosts and geographical regions. The rop17 gene was amplified and sequenced from 10 T. gondii strains, and phylogenetic relationship among these T. gondii strains was reconstructed using maximum parsimony (MP, neighbor-joining (NJ, and maximum likelihood (ML analyses. The partial rop17 gene sequences were 1375 bp in length and A+T contents varied from 49.45% to 50.11% among all examined T. gondii strains. Sequence analysis identified 33 variable nucleotide positions (2.1%, 16 of which were identified as transitions. Phylogeny reconstruction based on rop17 gene data revealed two major clusters which could readily distinguish Type I and Type II strains. Analyses of sequence variations in nucleotides and amino acids among these strains revealed high ratio of nonsynonymous to synonymous polymorphisms (>1, indicating that rop17 shows signs of positive selection. This study demonstrated the existence of slightly high sequence variability in the rop17 gene sequences among T. gondii strains from different hosts and geographical regions, suggesting that rop17 gene may represent a new genetic marker for population genetic studies of T. gondii isolates.

  15. Structure of Toxoplasma gondii fructose-1,6-bisphosphate aldolase

    International Nuclear Information System (INIS)

    Boucher, Lauren E.; Bosch, Jürgen

    2014-01-01

    The structure of T. gondii fructose-1,6-bisphosphate aldolase, a glycolytic enzyme and structural component of the invasion machinery, was determined to a resolution of 2.0 Å. The apicomplexan parasite Toxoplasma gondii must invade host cells to continue its lifecycle. It invades different cell types using an actomyosin motor that is connected to extracellular adhesins via the bridging protein fructose-1,6-@@bisphosphate aldolase. During invasion, aldolase serves in the role of a structural bridging protein, as opposed to its normal enzymatic role in the glycolysis pathway. Crystal structures of the homologous Plasmodium falciparum fructose-1,6-bisphosphate aldolase have been described previously. Here, T. gondii fructose-1,6-bisphosphate aldolase has been crystallized in space group P22 1 2 1 , with the biologically relevant tetramer in the asymmetric unit, and the structure has been determined via molecular replacement to a resolution of 2.0 Å. An analysis of the quality of the model and of the differences between the four chains in the asymmetric unit and a comparison between the T. gondii and P. falciparum aldolase structures is presented

  16. Modulating effect of Allium cepa on kidney apoptosis caused by Toxoplasma gondii

    Directory of Open Access Journals (Sweden)

    Yaghub gharadaghi

    2012-06-01

    Full Text Available Purpose: Toxoplasma gondii is a widespread protozoan parasite that infects a broad range of warm blooded animals as well as humans. The present study was investigated to evaluate the effects of allium cepa on renal failur in male rats which experimentally infected by Toxoplasma gondii, RH strain. Methods: Wistar male rat (n=40 were allocated into four groups, group one that received tachyzoites of T. gondii (ip (n=10, group two that received tachyzoites of T. gondii (ip, plus fresh onion juice by gavages method (n=10, group three received just fresh onion juice by gavages method (n=10 and control group (n=10 that received nothing. Animals were kept in standard condition. In 30 day after inducing Toxoplasma infection, 5cc blood was collected for serum protein and TAC levels. Kidney tissues of Rat in whole groups were removed and prepared for apopetosis analysis. Results: Serum protein and kidneys weights were significantly decreased in groups that were infected with T. gondii, in comparison to control and onions groups. Kidneys Apopetosis in toxoplasma group significantly increased in comparison to control group (P<0.05.level of TAC was significantly increased in groups that received onio juice (P<0.05. Conclusion: This study showed that T. gondii have significantly effect on serum protein and TAC, apopetosis and fresh onion juice returned and treated this harmful effect, so it is suggested that eating of onion is useful in toxoplasma infection.

  17. Detection Method of TOXOPLASMA GONDII Tachyzoites

    Science.gov (United States)

    Eassa, Souzan; Bose, Chhanda; Alusta, Pierre; Tarasenko, Olga

    2011-06-01

    Tachyzoites are considered to be the most important stage of Toxoplasma gondii which causes toxoplasmosis. T. gondii is, an obligate intracellular parasite which infects a wide range of cells. The present study was designed to develop a method for an early detection of T. gondii tachyzoites. The method comprised of a binding assay which was analyzed using principal component and cluster analysis. Our data showed that glycoconjugates GC1, GC2, GC3 and GC10 exhibit a significantly higher binding affinity for T. gondii tachyzoites as compared to controls (T. gondii only, PAA only, GC 1, 2, 3, and 10 only).

  18. A quantitative assay method of Toxoplasma gondii HSP70 mRNA by quantitative competitive-reverse transcriptase-PCR.

    Science.gov (United States)

    Piao, Lian-Xun; Aosai, Fumie; Chen, Mei; Fang, Hao; Mun, Hye-Seong; Norose, Kazumi; Yano, Akihiko

    2004-03-01

    Toxoplasma gondii (T. gondii)-derived heat shock protein 70 (T.g.HSP70) has been identified as a virulent molecule expressing only in T. gondii tachyzoites during lethal acute infection. Therefore, it is of importance to determine the expression of T.g.HSP70 mRNA in a quantitative manner for analysis of virulence of T. gondii in tissues. We have constructed a competitor T.g.HSP70 and have successfully established a quantitative competitive-reverse transcriptase-polymerase chain reaction (QC-RT-PCR) targeting T.g.HSP70 gene. By using the established QC-RT-PCR method, we have demonstrated that the copy number of T.g.HSP70 mRNA per T. gondii tachyzoite was highest in the lung among the organs examined in interferon-gamma knockout (GKO) mice.

  19. Towards a molecular architecture of the centrosome in Toxoplasma gondii.

    Science.gov (United States)

    Morlon-Guyot, Juliette; Francia, Maria E; Dubremetz, Jean-François; Daher, Wassim

    2017-02-01

    Toxoplasma gondii is the causative agent of toxoplasmosis. The pathogenicity of this unicellular parasite is tightly linked to its ability to efficiently proliferate within its host. Tachyzoites, the fast dividing form of the parasite, divide by endodyogeny. This process involves a single round of DNA replication, closed nuclear mitosis, and assembly of two daughter cells within a mother. The successful completion of endodyogeny relies on the temporal and spatial coordination of a plethora of simultaneous events. It has been shown that the Toxoplasma centrosome serves as signaling hub which nucleates spindle microtubules during mitosis and organizes the scaffolding of daughter cells components during cytokinesis. In addition, the centrosome is essential for inheriting both the apicoplast (a chloroplast-like organelle) and the Golgi apparatus. A growing body of evidence supports the notion that the T. gondii centrosome diverges in protein composition, structure and organization from its counterparts in higher eukaryotes making it an attractive source of potentially druggable targets. Here, we summarize the current knowledge on T. gondii centrosomal proteins and extend the putative centrosomal protein repertoire by in silico identification of mammalian centrosomal protein orthologs. We propose a working model for the organization and architecture of the centrosome in Toxoplasma parasites. Experimental validation of our proposed model will uncover how each predicted protein translates into the biology of centrosome, cytokinesis, karyokinesis, and organelle inheritance in Toxoplasma parasites. © 2016 Wiley Periodicals, Inc.

  20. In silico Analysis of Immunologic Regions of Surface Antigens (Sags of Toxoplasma gondii

    Directory of Open Access Journals (Sweden)

    Abbas Alibakhshi

    2017-06-01

    Full Text Available Background: Surface antigens (SAGs of Toxoplasma gondii are known candidates for diagnostic tests and vaccines. The present study argues about the main necessary properties for determination and prediction of T-cell agretopes and B-cell epitopes of surface antigens of Toxoplasma gondii.Materials and Methods: Primary, secondary and tertiary structures of the proteins were analyzed by different methods. The three-dimensional structures were determined by use of ab initio method for prediction of discontinues epitopes. The agretopes and epitopes were predicted via several various web servers with different methods employed.Results: The results of in silico analyses showed that the regions 129-GAPAGRNNDGSSAPT-143 for protein p22, 234-SENPWQGNASSD-245 for protein p30 and 348-PGTEGESQAGT-358 for protein p43, have the highest immunogenic potential.Conclusion: We reached to three antigenic epitopes for cloning and protein expression. In following the purified polypeptide will be applied for diagnosis of Toxoplasma gondii.

  1. Dual Identification and Analysis of Differentially Expressed Transcripts of Porcine PK-15 Cells and Toxoplasma gondii during in vitro Infection

    Directory of Open Access Journals (Sweden)

    Chun-Xue eZhou

    2016-05-01

    Full Text Available Toxoplasma gondii is responsible for causing toxoplasmosis, one of the most prevalent zoonotic parasitoses worldwide. The mechanisms that mediate T. gondii infection of pigs (the most common source of human infection and renal tissues are still unknown. To identify the critical alterations that take place in the transcriptome of both porcine kidney (PK-15 cells and T. gondii following infection, infected cell samples were collected at 1, 3, 6, 9, 12, 18, and 24 h post infection and RNA-Seq data were acquired using Illumina Deep Sequencing. Differential Expression of Genes (DEGs analysis was performed to study the concomitant gene-specific temporal patterns of induction of mRNA expression of PK-15 cells and T. gondii. High sequence coverage enabled us to thoroughly characterize T. gondii transcriptome and identify the activated molecular pathways in host cells. More than 6G clean bases/ sample, including > 40 million clean reads were obtained. These were aligned to the reference genome of T. gondii and wild boar (Sus scrofa. DEGs involved in metabolic activities of T. gondii showed time-dependent down-regulation. However, DEGs involved in immune or disease related pathways of PK-15 cells peaked at 6 h PI, and were highly enriched as evidenced by KEGG analysis. Protein-protein interaction analysis revealed that TGME49_120110 (PCNA, TGME49_049180 (DHFR-TS, TGME49_055320 and TGME49_002300 (ITPase are the four hub genes with most interactions with T. gondii at the onset of infection. These results reveal altered profiles of gene expressed by PK-15 cells and T. gondii during infection and provide the groundwork for future virulence studies to uncover the mechanisms of T. gondii interaction with porcine renal tissue by functional analysis of these DEGs.

  2. [Expression, purification and serological reactivity of a chimeric antigen of GRA6 with P30 from Toxoplasma gondii].

    Science.gov (United States)

    Li, Yue-Xi; Zhang, Jin-Hai; Tao, Kai-Hua; Huang, Pei-Tang

    2003-11-01

    Major surface protein (p30) and Dense Granule Antigen GRA6 of Toxoplasma gondii have good antigenicity, and could be used for detection of IgM against Toxoplasma gondii. GRA6 may complement P30 to reach more high sensitivity for detection of antibodies to Toxoplasma gondii, so, we try to express the chimeric protein of GRA6 and P30 by genetic engineering, identify its antignenicity and use for developing diagnosis reagent. Antigenic domains of p30 and GRA6 of Toxoplasma gondii were screened by analyzing their sequences using the software ANTHEWIN. Two DNA fragments encoding respectively antigenic domains of p30 and GRA6 were cloned, they were inserted into the same expression vector pET28a( + ) and expressed as a chimeric protein in Escherichia coli. BL21(DE3), the expressed chimeric protein of p30 with GRA6 in a form of inclusion body was about 25% of total proteins of E. coli. BL21(DE3). The inclusion body was washed once with 0.5% Triton X-100 and dissolved with 0.5% SKL, after renaturation by gradient dialysis, the recombinant protein was purified by DEAE-Sepharose FF cation column and then detected with 12% SDS-PAGE, it exists mainly in the eluted peak with 300 mmol/L NaCl and has high purity. By using enzyme-linked immunosorbent assay (ELISA), the recombinant protein was examined for reactivity with immunoglobulin M (IgM) antibodies in 6 sera from patients infected with Toxoplasma gondii ., it was reactive with all the 6 sera but not with sera from normal people, these results showed that the recombinant chimeric antigen has good antigenicity and specificity and could be used for detection of IgM against Toxoplasma gondii. The expressed chimeric protein could be used for epidemic investigation of Toxoplasma gondii, blood donor screening, especially for detection of pregnant women, and is of great significance in prevention of Toxoplasma gondii infection.

  3. Hepatoprotective activity of Thymus vulgaris extract against Toxoplasma gondii infection

    Directory of Open Access Journals (Sweden)

    Nagwa Mostafa El-Sayed

    2017-05-01

    Full Text Available Objective: To evaluate the hepatoprotective activity of Thymus vulgaris (T. vulgaris extract against Toxoplasma gondii (T. gondii infection in experimentally infected mice. Methods: Sixty mice were divided into six groups (Group I–Group VI. Group I was normal control (non-infected, non-treated; Group II was non-infected and treated with T. vulgaris extract (500 mg/kg; Group III was T. gondii infected-non-immunosuppressed control; Group IV consisted of infected immunosuppressed mice; Group V was infected and treated with T. vulgaris extract; Group VI consisted of infected immunosuppressed mice treated with T. vulgaris extract. Hepatoprotective effect of T. vulgaris extract was evaluated by histopathological examination of tissue sections stained with hematoxylin and eosin, determination of liver function parameters (alanine aminotransaminase, aspartate aminotransaminase and alkaline phosphates, total bilirubin, total protein concentrations and assessment of hepatocytes genotoxicity by comet assay.Antigenotoxic effect of T. vulgaris was assessed by several comet assay parameters that were provided by the image analysis software, including % tailed cells, % of DNA in the tail, tail length, and tail moment. Results: Treatment with T. vulgaris in both Groups V and VI improved T. gondii induced pathological lesions in the infected liver that regressed to near the normal picture especially in Group V. Also, it restored the altered values of liver function parameters near to the normal levels significantly (P < 0.05 compared with Groups III and IV respectively. Regarding comet assay parameters, all of them were significantly increased (P < 0.05 after T. gondii infection (Group III and reached the greatest values in infected immunosuppressed group (Group IV compared to the normal controls (Group I. With treatment by T. vulgaris in Groups V and VI, there was a significant decrease (P < 0.05 in all values compared to Groups III and V respectively. The

  4. Toxoplasma gondii Proliferation Require Down-Regulation of Host Nox4 Expression via Activation of PI3 Kinase/Akt Signaling Pathway.

    Directory of Open Access Journals (Sweden)

    Wei Zhou

    Full Text Available Toxoplasma gondii results in ocular toxoplasmosis characterized by chorioretinitis with inflammation and necrosis of the neuroretina, pigment epithelium, and choroid. After invasion, T. gondii replicates in host cells before cell lysis, which releases the parasites to invade neighboring cells to repeat the life cycle and establish a chronic retinal infection. The mechanism by which T. gondii avoids innate immune defense, however, is unknown. Therefore, we determined whether PI3K/Akt signaling pathway activation by T. gondii is essential for subversion of host immunity and parasite proliferation. T. gondii infection or excretory/secretory protein (ESP treatment of the human retinal pigment epithelium cell line ARPE-19 induced Akt phosphorylation, and PI3K inhibitors effectively reduced T. gondii proliferation in host cells. Furthermore, T. gondii reduced intracellular reactive oxygen species (ROS while activating the PI3K/Akt signaling pathway. While searching for the main source of these ROS, we found that NADPH oxidase 4 (Nox4 was prominently expressed in ARPE-19 cells, and this expression was significantly reduced by T. gondii infection or ESP treatment along with decreased ROS levels. In addition, artificial reduction of host Nox4 levels with specific siRNA increased replication of intracellular T. gondii compared to controls. Interestingly, these T. gondii-induced effects were reversed by PI3K inhibitors, suggesting that activation of the PI3K/Akt signaling pathway is important for suppression of both Nox4 expression and ROS levels by T. gondii infection. These findings demonstrate that manipulation of the host PI3K/Akt signaling pathway and Nox4 gene expression is a novel mechanism involved in T. gondii survival and proliferation.

  5. Toxoplasma gondii in animals and the environment

    OpenAIRE

    Parigi, Maria

    2014-01-01

    Toxoplasma gondii is an obligate intracellular parasite capable of infecting virtually all warm-blooded species, including humans, but cats are the only definitive hosts. Humans or animals acquire T. gondii infection by ingesting food or water contaminated with sporulated oocysts or by ingesting tissue cysts containing bradyzoites. Toxoplasmosis has the highest human incidence among zoonotic parasitic diseases, but it is still considered an underreported zoonosis. The importance of T. gondii ...

  6. Evasion of Human Neutrophil-Mediated Host Defense during Toxoplasma gondii Infection.

    Science.gov (United States)

    Lima, Tatiane S; Gov, Lanny; Lodoen, Melissa B

    2018-02-13

    Neutrophils are a major player in host immunity to infection; however, the mechanisms by which human neutrophils respond to the intracellular protozoan parasite Toxoplasma gondii are still poorly understood. In the current study, we found that, whereas primary human monocytes produced interleukin-1beta (IL-1β) in response to T. gondii infection, human neutrophils from the same blood donors did not. Moreover, T. gondii inhibited lipopolysaccharide (LPS)-induced IL-1β synthesis in human peripheral blood neutrophils. IL-1β suppression required active parasite invasion, since heat-killed or mycalolide B-treated parasites did not inhibit IL-1β release. By investigating the mechanisms involved in this process, we found that T. gondii infection of neutrophils treated with LPS resulted in reduced transcript levels of IL-1β and NLRP3 and reduced protein levels of pro-IL-1β, mature IL-1β, and the inflammasome sensor NLRP3. In T. gondii -infected neutrophils stimulated with LPS, the levels of MyD88, TRAF6, IKKα, IKKβ, and phosphorylated IKKα/β were not affected. However, LPS-induced IκBα degradation and p65 phosphorylation were reduced in T. gondii- infected neutrophils, and degradation of IκBα was reversed by treatment with the proteasome inhibitor MG-132. Finally, we observed that T. gondii inhibited the cleavage and activity of caspase-1 in human neutrophils. These results indicate that T. gondii suppression of IL-1β involves a two-pronged strategy whereby T. gondii inhibits both NF-κB signaling and activation of the NLRP3 inflammasome. These findings represent a novel mechanism of T. gondii evasion of human neutrophil-mediated host defense by targeting the production of IL-1β. IMPORTANCE Toxoplasma gondii is an obligate intracellular parasite that infects approximately one-third of humans worldwide and can invade virtually any nucleated cell in the human body. Although it is well documented that neutrophils infiltrate the site of acute T. gondii

  7. Cloning and Clone Analysis of GRA1 Gene from Local Isolate Toxoplasma gondii Tachyzoite

    Directory of Open Access Journals (Sweden)

    Didik T Subekti

    2008-03-01

    Full Text Available The GRA1 gene of Toxoplasma gondii encoding protein called GRA1 protein. GRA1 protein known to be immunogenic and essentialy involved in modification of parasitophorus vacoule which has role in immune evasion and virulency of organism. The local isolate of T. gondii is successfuly isolated and known as highly pathogenic isolate similarly as its RH strain. Unfortunately, the homology sequence of GRA1 gene between those isolate still unknown. The purpose of the research are to clone the GRA1 gene and to analyze the homology from pathogenic T. gondii isolate and RH strain. Tachyzoite of T. gondii was grown in mice peritoneum by intraperitoneal injection. Then, total mRNA was isolated and purified. cDNA was synthesized from mRNA and then amplified using F1 dan R1 primers to get clone of GRA1 from local isolate. Homology analysis was perform using several bioinformatic softwares. The result showed that cDNA of GRA1 from local isolate has 84% homologs with RH strain of T.gondii. However, when subsequently editing performed to parts of suspected non coding sequence of cDNA GRA1 to get CDS of GRA1, the homology was increase to 100% compare to CDS of GRA1 of RH strain.

  8. Toxoplasma gondii: further studies on the subpellicular network

    Directory of Open Access Journals (Sweden)

    Leandro Lemgruber

    2009-08-01

    Full Text Available The association of the pellicle with cytoskeletal elements in Toxoplasma gondii allows this parasite to maintain its mechanical integrity and makes possible its gliding motility and cell invasion. The inner membrane complex (IMC resembles the flattened membrane sacs observed in free-living protozoa and these sacs have been found to associate with cytoskeletal proteins such as articulins. We used immunofluorescence microscopy to characterise the presence and distribution of plateins, a sub-family of articulins, in T. gondii tachyzoites. A dispersed labelling of the whole protozoan body was observed. Electron microscopy of detergent-extracted cells revealed the presence of a network of 10 nm filaments distributed throughout the parasite. These filaments were labelled with anti-platein antibodies. Screening the sequenced T. gondii genome, we obtained the sequence of an IMC predicted protein with 25% identity and 42% similarity to the platein isoform alpha 1 present in Euplotes aediculatus, but with 42% identity and 55% similarity to that found in Euglena gracilis, suggesting strong resemblance to articulins.

  9. Seroprevalence of Toxoplasma gondii infection amongst residents ...

    African Journals Online (AJOL)

    Toxoplasmosis is a zoonotic disease, recognized as a serious public health problem worldwide. Toxoplasma gondii infection has become a major public health concern in recent years due to the ravaging HIV/AIDS pandemic. A serological survey was carried out in Tanga district of north-eastern Tanzania to assess T. gondii ...

  10. Toxoplasma gondii, Mental Health and Shizophrenia

    Directory of Open Access Journals (Sweden)

    Sibel Cevizci

    2013-04-01

    Full Text Available Protecting and promoting of mental health is one of the major application areas of public health. In particular, Toxoplasma gondii, which is a protozoal zoonosis common in Turkey, it is closely related to veterinary public health. In recent years, T.gondii can induce behavioral changes, may play a role in schizophrenia as an etiologic factor. Results of the recently performed studies shows that T.gondii may be a potential factor for some neuropathological changes in brain and suicide attemption. The purpose of this review is to present the data on recent epidemiology of T.gondii, mental health effects (changes in behavior, suicide, etc., the relationship between T.gondii and schizophrenia and offer some recommendations for protecting of public health. [TAF Prev Med Bull 2013; 12(2.000: 199-208

  11. Immunopathogenecity of Different Types of Toxoplasma Gondii

    Directory of Open Access Journals (Sweden)

    Didik T Subekti

    2006-09-01

    Full Text Available Toxoplasmosis is a zoonotic disease caused by Toxoplasma gondii . The disease was widely found in high prevalence around the world . Seroprevalence of human toxoplasmosis in Indonesia was 43 - 88% while toxoplasmosis in animals was reported 6 - 70%. In the past, clinically manifestation of toxoplasmosis only occurred in individu which has immunodeficient or immunosupression . Recently, more evident showed that individu which has immunocompetent was also able to develop clinical signs when infected by pathogenic T gondii (type I of T gondii . In fact, the pathogenicity of T. gondii depends on the type or closet which originated from their clonal population . Each type has different implication on clinical immunopatho genesis . In this paper, the differences of biological character, immunopathogenicity and their clinical implication of T gondii clonal population structure are reviewed.

  12. Toxoplasma gondii actively inhibits neuronal function in chronically infected mice.

    Directory of Open Access Journals (Sweden)

    Fahad Haroon

    Full Text Available Upon infection with the obligate intracellular parasite Toxoplasma gondii, fast replicating tachyzoites infect a broad spectrum of host cells including neurons. Under the pressure of the immune response, tachyzoites convert into slow-replicating bradyzoites, which persist as cysts in neurons. Currently, it is unclear whether T. gondii alters the functional activity of neurons, which may contribute to altered behaviour of T. gondii-infected mice and men. In the present study we demonstrate that upon oral infection with T. gondii cysts, chronically infected BALB/c mice lost over time their natural fear against cat urine which was paralleled by the persistence of the parasite in brain regions affecting behaviour and odor perception. Detailed immunohistochemistry showed that in infected neurons not only parasitic cysts but also the host cell cytoplasm and some axons stained positive for Toxoplasma antigen suggesting that parasitic proteins might directly interfere with neuronal function. In fact, in vitro live cell calcium (Ca(2+ imaging studies revealed that tachyzoites actively manipulated Ca(2+ signalling upon glutamate stimulation leading either to hyper- or hypo-responsive neurons. Experiments with the endoplasmatic reticulum Ca(2+ uptake inhibitor thapsigargin indicate that tachyzoites deplete Ca(2+ stores in the endoplasmatic reticulum. Furthermore in vivo studies revealed that the activity-dependent uptake of the potassium analogue thallium was reduced in cyst harbouring neurons indicating their functional impairment. The percentage of non-functional neurons increased over time In conclusion, both bradyzoites and tachyzoites functionally silence infected neurons, which may significantly contribute to the altered behaviour of the host.

  13. Genotyping of polymorphic effectors of Toxoplasma gondii isolates from China

    Directory of Open Access Journals (Sweden)

    Weisheng Cheng

    2017-11-01

    Full Text Available Abstract Background Toxoplasma gondii is an opportunistic protozoan apicomplexan and obligate intracellular parasite that infects a wide range of animals and humans. Rhoptry proteins 5 (ROP5, ROP16, ROP18 and dense granules 15 (GRA15 are the important effectors secreted by T. gondii which link to the strain virulence for mice and modulate the host’s response to the parasite. Little has been known about these molecules as well as GRA3 in type Chinese 1 strains that show polymorphism among strains of archetypical genotypes. This study examined the genetic diversity of these effectors and its correlated virulence in mice among T. gondii isolates from China. Results Twenty-one isolates from stray cats were detected, of which 15 belong to Chinese 1, and 6 to ToxoDB #205. Wh6 isolate, a Chinese 1 strain, has an avirulent phenotype. PCR-RFLP results of ROP5 and ROP18 presented few variations among the strains. Genotyping of GRA15 and ROP16 revealed that all the strains belong to type II allele except Xz7 which carries type I allele. ROP16 amino acid alignment at 503 locus demonstrated that 17 isolates are featured as type I or type III (ROP16I/III, and the other 4 as type II (ROP16II. The strains investigated may be divided into four groups based on GRA3 amino acid alignment, and all isolates of type Chinese 1 belong to the μ-1 allele except Wh6 which is identical to type II strain. Conclusions PCR-RFLP and sequence alignment analyses of ROP5, ROP16, ROP18, GRA3, and GRA15 in T. gondii revealed that strains with the same genotype may have variations in some of their key genes. GRA3 variation exhibited by Wh6 strain may be associated with the difference in phenotype and pathogenesis.

  14. Constitutive expression and characterization of a surface SRS (NcSRS67) protein of Neospora caninum with no orthologue in Toxoplasma gondii.

    Science.gov (United States)

    Bezerra, Marcos Alexandre; Pereira, Luiz Miguel; Bononi, Aline; Biella, Carla Agostino; Baroni, Luciana; Pollo-Oliveira, Leticia; Yatsuda, Ana Patrícia

    2017-04-01

    Neospora caninum is a parasite of the Apicomplexa phylum responsible for abortion and losses of fertility in cattle. As part of its intracellular cycle, the first interaction of the parasite with the target cell is performed with the surface proteins known as the SRS superfamily (Surface Antigen Glycoprotein - Related Sequences). SAG related or SRS proteins have been a target of intense research due to its immunodominant pattern, exhibiting potential as diagnostic and/or vaccine candidates. The aim of this study was the cloning, expression and characterization of the gene NcSRS67 of N. caninum using a novel designed plasmid. The coding sequence of NcSRS67 (without the signal peptide and the GPI anchor) was cloned and expressed constitutively instead of the ccdB system of pCR-Blunt II-TOPO. The protein was purified in a nickel sepharose column and identified by mass spectrometry (MS/MS). The constitutive expression did not affect the final bacterial growth, with a similar OD 600nm compared to the non-transformed strains. The recombinant NcSRS67 was over expressed and the native form was detected by the anti-rNcSRS67 serum on 1D western blot as a single band of approximately 38kDa as predicted. On an in vitro assay, the inhibitory effect of the polyclonal antiserum anti-rNcSRS67 was nearly 20% on adhesion/invasion of host cells. The NcSRS67 native protein was localised on part of the surface of N. caninum tachyzoite when compared to the nucleus by confocal immunofluorescence. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Toxoplasma gondii Infection Promotes Epithelial Barrier Dysfunction of Caco-2 Cells

    Science.gov (United States)

    Briceño, Marisol Pallete; Nascimento, Layane Alencar Costa; Nogueira, Nathalia Pires; Barenco, Paulo Victor Czarnewski; Ferro, Eloisa Amália Vieira; Rezende-Oliveira, Karine; Goulart, Luiz Ricardo; Alves, Patrícia Terra; Barbosa, Bellisa de Freitas; Lima, Wânia Rezende; Silva, Neide Maria

    2016-01-01

    After oral infection, Toxoplasma gondii invades intestinal cells, induces breakdown of intestinal physiology and barrier functions, and causes intestinal pathology in some animal species. Although parasites’ invasion into host cells is a known phenomenon, the effects of T. gondii infection in the intestinal barrier are still not well established. To evaluate morphological and physiological modifications on the colorectal adenocarcinoma-derived Caco-2 cell line during T. gondii infection, microvilli, tight junction integrity, and transepithelial electrical resistance (TEER) were investigated under infection. It was observed that the dextran uptake (endocytosis) and distribution were smaller in infected than in noninfected Caco-2 cells. The infection leads to the partial loss of microvilli at the cell surface. Claudin-1, zonula occludens-1 (ZO-1), and occludin expressions were colocalized by immunofluorescence and presented discontinuous net patterns in infected cells. Immunoblotting analysis at 24 hr postinfection revealed decreasing expression of occludin and ZO-1 proteins, whereas claudin-1 presented similar expression level compared with noninfected cells. T. gondii decreased TEER in Caco-2 cells 24 hr after infection. Our results suggest that T. gondii infection may lead to the loss of integrity of intestinal mucosa, resulting in impaired barrier function. PMID:27370796

  16. Toxoplasma gondii seroprevalence varies by cat breed.

    Directory of Open Access Journals (Sweden)

    Kärt Must

    Full Text Available Toxoplasma gondii is a widespread zoonotic parasite that is relevant for veterinary and public health. The domestic cat, the definitive host species with the largest worldwide population, has become evolutionarily and epidemiologically the most important host of T. gondii. The outcome of T. gondii infection is influenced by congenital and acquired host characteristics. We detected differences in T. gondii seroprevalence by cat breed in our previous studies. The aims of this study were to estimate T. gondii seroprevalence in selected domestic cat breeds, and to evaluate whether being of a certain breed is associated with T. gondii seropositivity, when the age and lifestyle of the cat are taken into account. The studied breeds were the Birman, British Shorthair, Burmese, Korat, Norwegian Forest Cat, Ocicat, Persian, and Siamese. Plasma samples were analyzed for the presence of immunoglobulin G antibodies against T. gondii with a commercial direct agglutination test at dilution 1:40. The samples were accompanied by owner-completed questionnaires that provided background data on the cats. Overall, 41.12% of the 1121 cats tested seropositive, and the seroprevalence increased with age. The Burmese had the lowest seroprevalence (18.82% and the Persian had the highest (60.00%. According to the final multivariable logistic regression model, the odds to test seropositive were four to seven times higher in Birmans, Ocicats, Norwegian Forest Cats, and Persians when compared with the Burmese, while older age and receiving raw meat were also risk factors for T. gondii seropositivity. This study showed that T. gondii seroprevalence varies by cat breed and identified being of certain breeds, older age, and receiving raw meat as risk factors for seropositivity.

  17. ARF6, PI3-kinase and host cell actin cytoskeleton in Toxoplasma gondii cell invasion

    International Nuclear Information System (INIS)

    Vieira da Silva, Claudio; Alves da Silva, Erika; Costa Cruz, Mario; Chavrier, Philippe; Arruda Mortara, Renato

    2009-01-01

    Toxoplasma gondii infects a variety of different cell types in a range of different hosts. Host cell invasion by T. gondii occurs by active penetration of the host cell, a process previously described as independent of host actin polymerization. Also, the parasitophorous vacuole has been shown to resist fusion with endocytic and exocytic pathways of the host cell. ADP-ribosylation factor-6 (ARF6) belongs to the ARF family of small GTP-binding proteins. ARF6 regulates membrane trafficking and actin cytoskeleton rearrangements at the plasma membrane. Here, we have observed that ARF6 is recruited to the parasitophorous vacuole of tachyzoites of T. gondii RH strain and it also plays an important role in the parasite cell invasion with activation of PI3-kinase and recruitment of PIP 2 and PIP 3 to the parasitophorous vacuole of invading parasites. Moreover, it was verified that maintenance of host cell actin cytoskeleton integrity is important to parasite invasion.

  18. Adjuvanted multi-epitope vaccines protect HLA-A*1101 transgenic mice against Toxoplasma gondii

    Science.gov (United States)

    We created and tested multi-epitope DNA or protein vaccines with TLR4 ligand emulsion adjuvant (gluco glucopyranosyl lipid adjuvant in a stable emulsion (GLA-SE)) for their ability to protect against Toxoplasma gondii in HLA transgenic mice. Our constructs each included five of our best down selecte...

  19. Human Innate Immunity to Toxoplasma gondii Is Mediated by Host Caspase-1 and ASC and Parasite GRA15

    Science.gov (United States)

    Gov, Lanny; Karimzadeh, Alborz; Ueno, Norikiyo; Lodoen, Melissa B.

    2013-01-01

    ABSTRACT   Interleukin-1β (IL-1β) functions as a key regulator of inflammation and innate immunity. The protozoan parasite Toxoplasma gondii actively infects human blood monocytes and induces the production of IL-1β; however, the host and parasite factors that mediate IL-1β production during T. gondii infection are poorly understood. We report that T. gondii induces IL-1β transcript, processing/cleavage, and release from infected primary human monocytes and THP-1 cells. Treating monocytes with the caspase-1 inhibitor Ac-YVAD-CMK reduced IL-1β release, suggesting a role for the inflammasome in T. gondii-induced IL-1β production. This was confirmed by performing short hairpin RNA (shRNA) knockdown of caspase-1 and of the inflammasome adaptor protein ASC. IL-1β induction required active parasite invasion of monocytes, since heat-killed or mycalolide B-treated parasites did not induce IL-1β. Among the type I, II, and III strains of T. gondii, the type II strain induced substantially more IL-1β mRNA and protein release than did the type I and III strains. Since IL-1β transcript is known to be induced downstream of NF-κB signaling, we investigated a role for the GRA15 protein, which induces sustained NF-κB signaling in a parasite strain-specific manner. By infecting human monocytes with a GRA15-knockout type II strain and a type I strain stably expressing type II GRA15, we determined that GRA15 is responsible for IL-1β induction during T. gondii infection of human monocytes. This research defines a pathway driving human innate immunity by describing a role for the classical inflammasome components caspase-1 and ASC and the parasite GRA15 protein in T. gondii-induced IL-1β production. PMID:23839215

  20. Toxoplasma gondii is dependent on glutamine and alters migratory profile of infected host bone marrow derived immune cells through SNAT2 and CXCR4 pathways.

    Directory of Open Access Journals (Sweden)

    I-Ping Lee

    Full Text Available The obligate intracellular parasite, Toxoplasma gondii, disseminates through its host inside infected immune cells. We hypothesize that parasite nutrient requirements lead to manipulation of migratory properties of the immune cell. We demonstrate that 1 T. gondii relies on glutamine for optimal infection, replication and viability, and 2 T. gondii-infected bone marrow-derived dendritic cells (DCs display both "hypermotility" and "enhanced migration" to an elevated glutamine gradient in vitro. We show that glutamine uptake by the sodium-dependent neutral amino acid transporter 2 (SNAT2 is required for this enhanced migration. SNAT2 transport of glutamine is also a significant factor in the induction of migration by the small cytokine stromal cell-derived factor-1 (SDF-1 in uninfected DCs. Blocking both SNAT2 and C-X-C chemokine receptor 4 (CXCR4; the unique receptor for SDF-1 blocks hypermotility and the enhanced migration in T. gondii-infected DCs. Changes in host cell protein expression following T. gondii infection may explain the altered migratory phenotype; we observed an increase of CD80 and unchanged protein level of CXCR4 in both T. gondii-infected and lipopolysaccharide (LPS-stimulated DCs. However, unlike activated DCs, SNAT2 expression in the cytosol of infected cells was also unchanged. Thus, our results suggest an important role of glutamine transport via SNAT2 in immune cell migration and a possible interaction between SNAT2 and CXCR4, by which T. gondii manipulates host cell motility.

  1. Toxoplasma gondii infection in humans in China

    Directory of Open Access Journals (Sweden)

    He Shenyi

    2011-08-01

    Full Text Available Abstract Toxoplasmosis is a zoonotic infection of humans and animals, caused by the opportunistic protozoan Toxoplasma gondii, a parasite belonging to the phylum Apicomplexa. Infection in pregnant women may lead to abortion, stillbirth or other serious consequences in newborns. Infection in immunocompromised patients can be fatal if not treated. On average, one third of people are chronically infected worldwide. Although very limited information from China has been published in the English journals, T. gondii infection is actually a significant human health problem in China. In the present article, we reviewed the clinical features, transmission, prevalence of T. gondii infection in humans in China, and summarized genetic characterizations of reported T. gondii isolates. Educating the public about the risks associated with unhealthy food and life style habits, tracking serological examinations to special populations, and measures to strengthen food and occupational safety are discussed.

  2. Rapid discovery of inhibitors of Toxoplasma gondii using hybrid structure-based computational approach

    Science.gov (United States)

    Kortagere, Sandhya; Mui, Ernest; McLeod, Rima; Welsh, William J.

    2011-05-01

    Toxoplasma (T.) gondii, the causative agent of toxoplasmosis, is a ubiquitous opportunistic pathogen that infects individuals worldwide, and is a leading cause of severe congenital neurologic and ocular disease in humans. No vaccine to protect humans is available, and hypersensitivity and toxicity limit the use of the few available medicines. Therefore, safer and more effective medicines to treat toxoplasmosis are urgently needed. Using the Hybrid Structure Based (HSB) method, we have previously identified small molecule inhibitors of P. falciparum that seem to target a novel protein-protein interaction between the Myosin tail interacting protein and myosin light chain. This pathway has been hypothesized to be involved in invasion of host erythrocytes by the parasite and is broadly conserved among the apicomplexans. Guided by similar computational drug design approaches, we investigated this series of small molecules as potential inhibitors of T. gondii. Compound C3-21, identified as the most active inhibitor in this series, exhibited an IC50 value 500 nM against T. gondii. Among the 16 structural analogs of C3-21 tested thus far, nine additional compounds were identified with IC50 values <10.0 μM. In vitro assays have revealed that C3-21 markedly limits intracellular growth of T. gondii tachyzoites, but has no effect on host cell human foreskin fibroblasts (HFF) at concentrations more than a log greater than the concentration that inhibits the parasites.

  3. HLA-DP, HLA-DQ, and HLA-DR-restricted epitopes in GRA5 of toxoplasma gondii strains

    Science.gov (United States)

    Haryati, S.; Sari, Y.; Prasetyo, A. A.; Sariyatun, R.

    2016-01-01

    The dense granular (GRA) proteins of Toxoplasma gondii(T. gondii) have been demonstrated as potential sources of T. gondii vaccine antigens. However, data of the GRA5 protein are limited. This study analyzed twenty-one complete GRA5 sequences of T. gondii GT1, RH, ME49, VEG, MAS, RUB, FOU, p89, VAND, and GAB2-2007-GAL-DOM2 strains to identify potential epitopes restricted by Major Histocompatibility Complex class II (MHC- II) molecules (human leukocyte antigen (HLA)-DP, HLA-DQ, and HLA-DR) in the protein. In all T. gondii strains, peptides positioned at amino acid (aa) 15-29, 16-30, 17-31, 18-32, 19-33, 83-97, 84-98, 86-100, 87-101, 89-103, and 90-104 were predicted to pose high affinity and binding with HLA-DRB1*0101, HLA-DRB1*0301 (DR17), HLA-DRB1*0401 (DR4Dw4), HLA-DRB1*0701, HLA-DRB1*1101, HLA-DRB1*1501 (DR2b), and/or HLA-DRB5*0101. Considering the epitope's affinity, ligation strength, and hydrophilicity, LRLLRRRRRRAIQEE sequence (aa 90-104) restricted by HLA-DRB1*0101, HlA- DRB1*0301 (DR17), and HLA-DRB1*0401 (DR4Dw4) was considered as the most potential MHC-II epitope in GRA5 of T. gondii. These results would be useful for studies concerning in developing T. gondii vaccine and diagnostic method.

  4. Molecular detection of Toxoplasma gondii in snakes.

    Science.gov (United States)

    Nasiri, Vahid; Teymurzadeh, Shohreh; Karimi, Gholamreza; Nasiri, Mehdi

    2016-10-01

    Toxoplasma gondii, an obligate intracellular protozoan parasite, is responsible for one of the most common zoonotic parasitic diseases in almost all warm-blooded vertebrates worldwide, and it is estimated that about one-third of the world human population is chronically infected with this parasite. Little is known about the circulation of T. gondii in snakes and this study for the first time aimed to evaluate the infection rates of snakes by this parasite by PCR methods. The brain of 68 Snakes, that were collected between May 2012 and September 2015 and died after the hold in captivity, under which they were kept for taking poisons, were examined for the presence of this parasite. DNA was extracted and Nested-PCR method was carried out with two of pairs of primers to detect the 344 bp fragment of T. gondii GRA6 gene. Five positive nested-PCR products were directly sequenced in the forward and reverse directions by Sequetech Company (Mountain View, CA). T. gondii GRA6 gene were detected from 55 (80.88%) of 68 snakes brains. Sequencing of the GRA6 gene revealed 98-100% of similarity with T. gondii sequences deposited in GenBank. To our knowledge, this is the first study of molecular detection of T. gondii in snakes and our findings show a higher frequency of this organism among them. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Toxoplasma gondii Infection Is Associated with Mitochondrial Dysfunction in-Vitro

    Directory of Open Access Journals (Sweden)

    Genevieve Syn

    2017-12-01

    Full Text Available Upon invasion of host cells, the ubiquitous pathogen Toxoplasma gondii manipulates several host processes, including re-organization of host organelles, to create a replicative niche. Host mitochondrial association to T. gondii parasitophorous vacuoles is rapid and has roles in modulating host immune responses. Here gene expression profiling of T. gondii infected cells reveals enrichment of genes involved in oxidative phosphorylation (OXPHOS and mitochondrial dysfunction 6 h post-infection. We identified 11 hub genes (HIF-1α, CASP8, FN1, POU5F1, CD44, ISG15, HNRNPA1, MDM2, RPL35, VHL, and NUPR1 and 10 predicted upstream regulators, including 4 endogenous regulators RICTOR, KDM5A, RB1, and D-glucose. We characterized a number of mitochondrial parameters in T. gondii infected human foreskin fibroblast cells over a 36 h time-course. In addition to the usual rapid recruitment and apparent enlargement of mitochondria around the parasitophorous vacuole we observed fragmented host mitochondria in infected cells, not linked to cellular apoptosis, from 24 h post-infection. An increase in mitochondrial superoxide levels in T. gondii infected cells was observed that required active parasite invasion and peaked at 30 h post-infection. Measurement of OXPHOS proteins showed decreased expression of Complex IV in infected cells at 24 h post-infection, followed by decreased expression of Complexes I and II at 36 h post-infection. No change occurred in Complex V. No difference in host mitochondrial membrane potential between infected and mock-infected cells was observed at any time. Our results show perturbation of host mitochondrial function following T. gondii infection that likely impacts on pathogenesis of disease.

  6. Proteomic characterization of the subpellicular cytoskeleton of Toxoplasma gondii tachyzoites.

    Science.gov (United States)

    Gómez de León, Carmen T; Díaz Martín, Rubén Darío; Mendoza Hernández, Guillermo; González Pozos, Sirenia; Ambrosio, Javier R; Mondragón Flores, Ricardo

    2014-12-05

    Toxoplasma, the causative agent of toxoplasmosis in animals and humans, has a subpellicular cytoskeleton that is involved in motility, cell shape and invasion. Knowledge of components of the cytoskeleton is necessary to understand the invasion mechanisms as well as for the identification of possible therapeutic targets. To date, most cytoskeletal components of Toxoplasma remain unidentified due mainly to the lack of reproducible methods for their isolation. Based on the successful isolation of the cytoskeleton, it was possible to report for the first time, the proteomic characterization of the subpellicular cytoskeleton of Toxoplasma formed by 95 cytoskeletal proteins through proteomic analysis by tandem mass spectrometry of one dimension SDS PAGE. By bioinformatic analysis of the data, proteins were classified as: 18 conventional cytoskeletal proteins; 10 inner membrane complex proteins, including 7 with alveolin repeats; 5 new proteins with alveolin like repeats; 37 proteins associated with other organelles and 25 novel proteins of unknown function. One of the alveolin like proteins not previously described in Toxoplasma named TgArticulin was partially characterized with a specific monoclonal antibody. Presence of TgArticulin was exclusively associated with the cytoskeleton fraction with a cortical distribution. Functions for the several molecules identified are proposed. This manuscript describes, for the first time, the proteome of the subpellicular cytoskeleton of Toxoplasma gondii. The importance of this study is related to the role of the cytoskeleton in the highly invasive capability of a parasite that causes abortion, blindness, and death by encephalitis in immunocompromised patients. Proteomic characterization of the cytoskeleton of T. gondii tachyzoites was possible by the development of a successful procedure for the isolation of the subpellicular cytoskeleton. Knowledge of the composition of the cytoskeleton of Toxoplasma is fundamental for the

  7. Seroprevalence of Toxoplasma gondii in wild kangaroos using an ELISA

    OpenAIRE

    Parameswaran, N.; O'Handley, RM.; Grigg, ME.; Fenwick, SG.; Thompson, RCA.

    2009-01-01

    Infection with Toxoplasma gondii is a significant problem in Australian marsupials, and can lead to devastating disease and predispose animals to predation. T. gondii infection in kangaroos is also of public health significance due to the kangaroo meat trade. A moderate seroprevalence of T. gondii was observed in a study of western grey kangaroos located in the Perth metropolitan area in Western Australia. Of 219 kangaroos tested, 15.5% (95%CI: 10.7-20.3) were positive for T. gondii antibodie...

  8. Secreted effectors in Toxoplasma gondii and related species: determinants of host range and pathogenesis?

    Science.gov (United States)

    English, E D; Adomako-Ankomah, Y; Boyle, J P

    2015-01-01

    Recent years have witnessed the discovery of a number of secreted proteins in Toxoplasma gondii that play important roles in host–pathogen interactions and parasite virulence, particularly in the mouse model. However, the role that these proteins play in driving the unique features of T. gondii compared to some of its nearest apicomplexan relatives (Hammondia hammondi and Neospora caninum) is unknown. These unique features include distinct dissemination characteristics in vivo and a vast host range. In this review we comprehensively survey what is known about disease outcome, the host response and host range for T. gondii, H. hammondi, and N. caninum. We then review what is presently known about recently identified secreted virulence effectors in these three genetically related, but phenotypically distinct, species. Finally we exploit the existence of genome sequences for these three organisms and discuss what is known about the presence, and functionality, of key T. gondii effectors in these three species. PMID:25655311

  9. Toxoplasma gondii seroprevalence in breeding pigs in Estonia

    DEFF Research Database (Denmark)

    Santoro, Azzurra; Tagel, Maarja; Must, Kärt

    2017-01-01

    Background: Toxoplasma gondii is a widespread occurring parasite infecting warm-blooded animals, including pigs and humans. The aims of this study were to estimate the prevalence of anti-T. gondii antibodies and to evaluate risk factors for T. gondii seropositivity in breeding pigs raised...... at least one seropositive pig. The proportion of seropositive pigs within the herds ranged between 0 and 43%. Gender appeared as a significant factor, with sows having 5.6 times higher odds to be seropositive to T. gondii than boars. Seroprevalence did not increase with age. Conclusions: Anti-T. gondii...

  10. Interaction and cystogenesis of Toxoplasma gondii within skeletal muscle cells in vitro

    Directory of Open Access Journals (Sweden)

    Erick Vaz Guimarães

    2009-03-01

    Full Text Available Infection by the protozoan parasite Toxoplasma gondii is widely prevalent in humans and animals. To prevent human infection, all meat should be well cooked before consumption, since the parasite is present in skeletal muscle. In this context, the use of skeletal muscle cells (SkMCs as a cellular model opens up new approaches to investigate T. gondii-host cell interactions. Immunofluorescent detection of proteins that are stage-specific for bradyzoites indicated that complete cystogenesis of T. gondii in in vitro cultures of SkMCs occurs after 96 h of infection. Ultrastructural analysis showed that, after 48 h of interaction, there were alterations on the parasitophorous vacuole membrane, including greater thickness and increased electron density at the inner face of the membrane. The present study demonstrates the potential use of primary cultures of SkMCs to evaluate different molecular aspects of T. gondii invasion and cystogenesis and presents a promising in vitro model for the screening of drug activities toward tissue cysts and bradyzoites.

  11. Targeted Delivery of Toxoplasma gondii Antigens to Dendritic Cells Promote Immunogenicity and Protective Efficiency against Toxoplasmosis

    Directory of Open Access Journals (Sweden)

    Zineb Lakhrif

    2018-02-01

    Full Text Available Toxoplasmosis is a major public health problem and the development of a human vaccine is of high priority. Efficient vaccination against Toxoplasma gondii requires both a mucosal and systemic Th1 immune response. Moreover, dendritic cells play a critical role in orchestrating the innate immune functions and driving specific adaptive immunity to T. gondii. In this study, we explore an original vaccination strategy that combines administration via mucosal and systemic routes of fusion proteins able to target the major T. gondii surface antigen SAG1 to DCs using an antibody fragment single-chain fragment variable (scFv directed against DEC205 endocytic receptor. Our results show that SAG1 targeting to DCs by scFv via intranasal and subcutaneous administration improved protection against chronic T. gondii infection. A marked reduction in brain parasite burden is observed when compared with the intranasal or the subcutaneous route alone. DC targeting improved both local and systemic humoral and cellular immune responses and potentiated more specifically the Th1 response profile by more efficient production of IFN-γ, interleukin-2, IgG2a, and nasal IgA. This study provides evidence of the potential of DC targeting for the development of new vaccines against a range of Apicomplexa parasites.

  12. The Evolution of Host Mitochondrial Association and its Impact on Toxoplasma gondii Infection

    Science.gov (United States)

    English, Elizabeth D.

    The association of intracellular pathogens with host mitochondria has been observed across taxa, from bacterial pathogens, such as Legionella pneumophila and Chlamydia trachomati, to the eukaryotic pathogen Toxoplasma gondii. However the functional impact of host mitochondrial association (HMA) remains difficult to assess in most of these species because in many cases the genes responsible for this phenomenon have not yet been identified. The recent discovery of the T. gondii gene responsible for HMA, Mitochondrial Association Factor 1 ( MAF1) has provided us with the tools to begin to understand the evolution and impact of HMA. Here we use multispecies sequence analysis to determine that the MAF1 locus is tandemly duplicated and diversified in both T. gondii and its nearest extant relative Hammondia hammondi, but not another close relative Neospora caninum. Using cross-species complementation we find that T. gondii and H. hammondi harbor copies of MAF1 able to mediate HMA, while N. caninum does not. We have begun mutational analysis using naturally occurring HMA+ and HMA- paralogs of MAF1 in order to determine the portions of MAF1 protein necessary for HMA. Additionally, we have identified the first in vivo phenotypes associated with HMA using multiple mouse models, for both acute and chronic infection. Taken together these data indicate that HMA likely evolved via neofunctionalization of a duplicated ancestral MAF1 gene, and that the neofunctionalized, HMA competent copy of MAF1 provides a selective advantage.

  13. Calcium uptake and proton transport by acidocalcisomes of Toxoplasma gondii.

    Directory of Open Access Journals (Sweden)

    Peter Rohloff

    Full Text Available Acidocalcisomes are acidic calcium stores found in diverse organisms, being conserved from bacteria to humans. They possess an acidic matrix that contains several cations bound to phosphates, which are mainly present in the form of short and long polyphosphate chains. Their matrix is acidified through the action of proton pumps such as a vacuolar proton ATPase and a vacuolar proton pyrophosphatase. Calcium uptake occurs through a Ca(2+/H(+ countertransporting ATPase located in the membrane of the organelle. Acidocalcisomes have been identified in a variety of microorganisms, including Apicomplexan parasites such as Plasmodium and Eimeria species, and in Toxoplasma gondii. We report the purification and characterization of an acidocalcisome fraction from T. gondii tachyzoites after subcellular fractionation and further discontinuous iodixanol gradient purification. Proton and calcium transport activities in the fraction were characterized by fluorescence microscopy and spectrophotometric methods using acridine orange and arsenazo III, respectively. This work will facilitate the understanding of the function of acidocalcisomes in Apicomplexan parasites, as we can now isolate highly purified fractions that could be used for proteomic analysis to find proteins that may clarify the biogenesis of these organelles.

  14. Sexual transmission of Toxoplasma gondii in sheep.

    Science.gov (United States)

    Lopes, Welber Daniel Zanetti; Rodriguez, Joana D'Ark; Souza, Fernando A; dos Santos, Thais Rabelo; dos Santos, Ricardo Silva; Rosanese, Walter Matheus; Lopes, Werik Renato Zanetti; Sakamoto, Cláudio Alessandro; da Costa, Alvimar José

    2013-07-01

    Male sheep of reproductive age were distributed into three groups: GI, a sheep inoculated (oral) with 2.0×10(5) oocysts of the P strain of Toxoplasma gondii; GII, a sheep infected (subcutaneous) with 1.0×10(6) tachyzoites of the RH strain of T. gondii; and GIII, a sheep kept as a control (not infected). After the inoculation of the males, 12 breeding ewes, which were not pregnant and which were serologically negative for reproductive diseases (particularly toxoplasmosis), were distributed into three groups, synchronized, and subsequently exposed to natural mating with previously inoculated males. The distribution was as follows: five ewes that underwent natural mating with the GI male, five ewes that were exposed to natural mating with the GII male, and two ewes that were mated with the non-infected male (control). Serum samples of all the ewes were collected on days -30, -14, -7, -1, and 0 (days before natural mating) and on days 1, 3, 5, 7, 11, 14, and weekly until birth; the presence of serum antibodies against T. gondii was assessed by IFAT. Using a bioassay and PCR, T. gondii was isolated from the semen of the infected reproducing sheep before mating. Following natural mating, 5 of the 12 females displayed antibodies specific for T. gondii; of these animals, two of the ewes underwent natural mating with the male inoculated with oocysts (GI) and three with the male infected with tachyzoites (GII). One of the females that displayed antibodies specific to this coccidian and that underwent natural mating with the GII sheep had a macerated fetus on the 70th day following coverage. Using a bioassay after the birth, it was possible to isolate T. gondii from samples of the "pool" of tissues from the five females that seroconverted after natural mating and from their respective lambs. Using PCR, the DNA of T. gondii was isolated from the "pool" of tissues from one and two females exposed to natural mating with the reproductive males infected with the oocysts and

  15. Toxoplasma gondii infection in pregnancy

    Directory of Open Access Journals (Sweden)

    Fabiana Maria Ruiz Lopes

    Full Text Available Toxoplasmosis is caused by an intracellular protozoan, Toxoplasma gondii, which has a wide geographical distribution. The main infection routes are ingestion of cysts from raw or badly-cooked meat, ingestion of oocysts from substrates contaminated with the feces of infected felines and congenital transmission by tachyzoites. The congenital form results in a severe systemic disease, because if the mother is infected for the first time during gestation, she can present a temporary parasitemia that will infect the fetus. Many of the clinical symptoms are seen in congenitally-infected children, from a mild disease to serious signs, such as mental retardation. Early diagnosis during the pregnancy is highly desirable, allowing prompt intervention in cases of infection, through treatment of pregnant women, reducing the probability of fetal infection and consequent substantial damage to the fetus. Conventional tests for establishment of a fetal diagnosis of toxoplasmosis include options from serology to PCR. Prevention of human toxoplasmosis is based on care to avoid infection, understanding the disease and serological exams during gestation. Pregnant women should be tested serologically from three months gestation, until one month after childbirth. Inclusion of serology for congenital toxoplasmosis along with the basic Guthrie test for PKU is of fundamental importance for early diagnosis of infection and so that treatment is initiated, in order to avoid possible sequels in the infant.

  16. Purine metabolism in Toxoplasma gondii

    International Nuclear Information System (INIS)

    Krug, E.C.; Marr, J.J.; Berens, R.L.

    1989-01-01

    We have studied the incorporation and interconversion of purines into nucleotides by freshly isolated Toxoplasma gondii. They did not synthesize nucleotides from formate, glycine, or serine. The purine bases hypoxanthine, xanthine, guanine, and adenine were incorporated at 9.2, 6.2, 5.1, and 4.3 pmol/10(7) cells/h, respectively. The purine nucleosides adenosine, inosine, guanosine, and xanthosine were incorporated at 110, 9.0, 2.7, and 0.3 pmol/10(7) cells/h, respectively. Guanine, xanthine, and their respective nucleosides labeled only guanine nucleotides. Inosine, hypoxanthine, and adenine labeled both adenine and guanine nucleotide pools at nearly equal ratios. Adenosine kinase was greater than 10-fold more active than the next most active enzyme in vitro. This is consistent with the metabolic data in vivo. No other nucleoside kinase or phosphotransferase activities were found. Phosphorylase activities were detected for guanosine and inosine; no other cleavage activities were detected. Deaminases were found for adenine and guanine. Phosphoribosyltransferase activities were detected for all four purine nucleobases. Interconversion occurs only in the direction of adenine to guanine nucleotides

  17. Cyst Formation from Virulent RH Strain of Toxoplasma gondii Tachyzoite: In Vitro Cultivation.

    Science.gov (United States)

    Salimi, Mahboobeh; Shojaee, Saeedeh; Keshavarz, Hossein; Mohebali, Mehdi

    2016-01-01

    This study was performed to induce conversion of RH strain tachyzoites of Toxoplasma gondii to bradyzoites by pH changing of the culture medium. HeLa cell monolayers were infected at a 1:1 tachyzoite to cell ratio. Four hours after infection, the culture medium was removed and replaced with culture medium and 5% FCS, adjusted to pH 8 with NaOH. The culture was maintained at 37 °C without CO2 until the end of the experiment. Cyst-like structures were collected and stained with periodic acid schiff (PAS) staining method. The soluble antigens of cyst-like structures of RH strain, in addition to RH tachyzoite, bradyzoites of avirulent Tehran strain and uninfected HeLa cells were electrophoresed on 12.5% polyacrylamide gel. The gel was stained by coomassie brilliant blue R-250. Four days after infection of HeLa cells with tachyzoites of T. gondii, RH strain, cyst- like structures were noticed and stained with PAS. In the SDS-PAGE, protein bands of these structures had some differences with tachyzoites of RH strain, but there was quite similarity between protein bands of these structures and tissue cysts (bradyzoites) of Tehran strains. P34 and P36 (bradyzoite-specific proteins) were observed only in T. gondii bradyzoites of RH (cyst like structures) and bradyzoites of Tehran strains. Alkalization of culture medium to pH 8 induced expression of bradyzoite- specific proteins and production of RH cysts in cell culture.

  18. Characteristics of Infection Immunity Regulated by Toxoplasma gondii to Maintain Chronic Infection in the Brain

    Directory of Open Access Journals (Sweden)

    Young Sang Hwang

    2018-02-01

    Full Text Available To examine the immune environment of chronic Toxoplasma gondii infection in the brain, the characteristics of infection-immunity (premunition in infection with T. gondii strain ME49 were investigated for 12 weeks postinfection (PI. The results showed that neuronal cell death, microglia infiltration and activation, inflammatory and anti-inflammatory cytokine expression, Stat1 phosphorylation, and microglia activation and inflammatory gene transcripts related to M1 polarization in the brain were increased during the acute infection (AI stage (within 6 weeks PI, suggesting that innate and cellular inflammatory response activation and neurodegeneration contributed to excessive inflammatory responses. However, these immune responses decreased during the chronic infection (CI stage (over 6 weeks PI with reductions in phosphorylated STAT1 (pSTAT1 and eosinophilic neurons. Notably, increases were observed in transcripts of T-cell exhaustion markers (TIM3, LAG3, KLRG1, etc., suppressor of cytokines signaling 1 protein (SOCS1, inhibitory checkpoint molecules (PD-1 and PD-L1, and Arg1 from the AI stage (3 weeks PI, implying active immune intervention under the immune environment of M1 polarization of microglia and increases in inflammatory cytokine levels. However, when BV-2 microglia were stimulated with T. gondii lysate antigens (strain RH or ME49 in vitro, nitrite production increased and urea production decreased. Furthermore, when BV-2 cells were infected by T. gondii tachyzoites (strain RH or ME49 in vitro, nitric oxide synthase and COX-2 levels decreased, whereas Arg1 levels significantly increased. Moreover, Arg1 expression was higher in ME49 infection than in RH infection, whereas nitrite production was lower in ME49 infection than in RH infection. Accordingly, these results strongly suggest that immune triggering of T. gondii antigens induces M1 polarization and activation of microglia as well as increase NO production, whereas T. gondii

  19. The aromatic amino acid hydroxylase genes AAH1 and AAH2 in Toxoplasma gondii contribute to transmission in the cat

    Science.gov (United States)

    The Toxoplasma gondii genome contains two aromatic amino acid hydroxylase genes, AAH1 and AAH2, which encode proteins that produce L-DOPA, which can serve as a precursor of catecholamine neurotransmitters. It has been suggested that this pathway elevates host dopamine levels thus making infected rod...

  20. Seroprevalence of Toxoplasma gondii and Neospora caninum ...

    African Journals Online (AJOL)

    The aim of this study was to compare the seroprevalence of Toxoplasma gondii and Neospora caninum in goats from two Argentinean provinces raised under different management conditions. A total of 2922 serum samples from adult goats of Córdoba (n=2187) and Buenos Aires provinces (n= 735), Argentina, were ...

  1. RESEARCH NOTE: AUTOFLUORESCENCE OF TOXOPLASMA GONDII OOCYSTS

    Science.gov (United States)

    This is the first report of a blue autofluorescence as a useful characteristic in the microscopic identification of Toxoplasma gondii oocysts. This autofluorescence appears to be of high intensity. Similar to the autofluorescence of related coccidia, the oocysts glow pale blue ...

  2. Mechanics of the Toxoplasma gondii oocyst wall

    Science.gov (United States)

    The ability of microorganisms to survive under extreme conditions is closely related to the physicochemical properties of their wall. In the ubiquitous protozoan parasite Toxoplasma gondii, the oocyst stage possesses a bilayered wall that protects the dormant but potentially infective parasites from...

  3. Toxoplasma gondii GRA7-Targeted ASC and PLD1 Promote Antibacterial Host Defense via PKCα.

    Directory of Open Access Journals (Sweden)

    Hyun-Jung Koh

    2017-01-01

    Full Text Available Tuberculosis is a global health problem and at least one-third of the world's population is infected with Mycobacterium tuberculosis (MTB. MTB is a successful pathogen that enhances its own intracellular survival by inhibiting inflammation and arresting phago-lysosomal fusion. We previously demonstrated that Toxoplasma gondii (T. gondii dense granule antigen (GRA 7 interacts with TNF receptor-associated factor 6 via Myeloid differentiation primary response gene 88, enabling innate immune responses in macrophages. To extend these studies, we found that GRA7 interacts with host proteins involved in antimicrobial host defense mechanisms as a therapeutic strategy for tuberculosis. Here, we show that protein kinase C (PKCα-mediated phosphorylation of T. gondii GRA7-I (Ser52 regulates the interaction of GRA7 with PYD domain of apoptosis-associated speck-like protein containing a carboxy-terminal CARD, which is capable of oligomerization and inflammasome activation can lead to antimicrobial defense against MTB. Furthermore, GRA7-III interacted with the PX domain of phospholipase D1, facilitating its enzyme activity, phago-lysosomal maturation, and subsequent antimicrobial activity in a GRA7-III (Ser135 phosphorylation-dependent manner via PKCα. Taken together, these results underscore a previously unrecognized role of GRA7 in modulating antimicrobial host defense mechanism during mycobacterial infection.

  4. The FIKK kinase of Toxoplasma gondii is not essential for the parasite's lytic cycle.

    Science.gov (United States)

    Skariah, S; Walwyn, O; Engelberg, K; Gubbels, M-J; Gaylets, C; Kim, N; Lynch, B; Sultan, A; Mordue, D G

    2016-05-01

    FIKK kinases are a novel family of kinases unique to the Apicomplexa. While most apicomplexans encode a single FIKK kinase, Plasmodium falciparum expresses 21 and piroplasms do not encode a FIKK kinase. FIKK kinases share a conserved C-terminal catalytic domain, but the N-terminal region is highly variable and contains no known functional domains. To date, FIKK kinases have been primarily studied in P. falciparum and Plasmodium berghei. Those that have been studied are exported from the parasite and associate with diverse locations in the infected erythrocyte cytosol or membrane. Deletion of individual P. falciparum FIKK kinases indicates that they may play a role in modification of the infected erythrocyte. The current study characterises the single FIKK gene in Toxoplasma gondii to evaluate the importance of the FIKK kinase in an apicomplexan that has a single FIKK kinase. The TgFIKK gene encoded a protein of approximately 280kDa. Endogenous tagging of the FIKK protein with Yellow Fluorescent Protein showed that the FIKK protein exclusively localised to the posterior end of tachyzoites. A Yellow Fluorescent Protein-tagged FIKK and a Ty-tagged FIKK both co-localised with T. gondii membrane occupation and recognition nexus protein to the basal complex and were localised apical to inner membrane complex protein-5 and Centrin2. Deletion of TgFIKK, surprisingly, had no detectable effect on the parasite's lytic cycle in vitro in human fibroblast cells or in acute virulence in vivo. Thus, our results clearly show that while the FIKK kinase is expressed in tachyzoites, it is not essential for the lytic cycle of T. gondii. Copyright © 2016 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.

  5. Pulmonary exposure to single-walled carbon nanotubes does not affect the early immune response against Toxoplasma gondii

    Directory of Open Access Journals (Sweden)

    Swedin Linda

    2012-05-01

    Full Text Available Abstract Background Single-walled carbon nanotubes (SWCNT trigger pronounced inflammation and fibrosis in the lungs of mice following administration via pharyngeal aspiration or inhalation. Human exposure to SWCNT in an occupational setting may occur in conjunction with infections and this could yield enhanced or suppressed responses to the offending agent. Here, we studied whether the sequential exposure to SWCNT via pharyngeal aspiration and infection of mice with the ubiquitous intracellular parasite Toxoplasma gondii would impact on the immune response of the host against the parasite. Methods C57BL/6 mice were pre-exposed by pharyngeal administration of SWCNT (80 + 80 μg/mouse for two consecutive days followed by intravenous injection with either 1x103 or 1x104 green fluorescence protein and luciferase-expressing T. gondii tachyzoites. The dissemination of T. gondii was monitored by in vivo bioluminescence imaging in real time for 7 days and by plaque formation. The inflammatory response was analysed in bronchoalveolar lavage (BAL fluid, and by assessment of morphological changes and immune responses in lung and spleen. Results There were no differences in parasite distribution between mice only inoculated with T. gondii or those mice pre-exposed for 2 days to SWCNT before parasite inoculum. Lung and spleen histology and inflammation markers in BAL fluid reflected the effects of SWCNT exposure and T. gondii injection, respectively. We also noted that CD11c positive dendritic cells but not F4/80 positive macrophages retained SWCNT in the lungs 9 days after pharyngeal aspiration. However, co-localization of T. gondii with CD11c or F4/80 positive cells could not be observed in lungs or spleen. Pre-exposure to SWCNT did not affect the splenocyte response to T. gondii. Conclusions Taken together, our data indicate that pre-exposure to SWCNT does not enhance or suppress the early immune response to T. gondii in mice.

  6. Mucosal immunity in Toxoplasma gondii infection.

    Science.gov (United States)

    Schulthess, J; Fourreau, D; Darche, S; Meresse, B; Kasper, L; Cerf-Bensussan, N; Buzoni-Gatel, D

    2008-09-01

    Toxoplasma gondii is an intracellular parasite that frequently infects a large spectrum of warm-blooded animals. This parasite induces abortion and establishes both chronic and silent infections, particularly in the brain. Parasite penetration into the host activates a strong anti-parasite immune response. In the present paper, we will discuss the interplay between innate and adaptive immunity that occurs within the infected intestine to clear the parasite and to maintain intestinal homeostasis despite the exacerbation of an inflammatory immune response.

  7. Toxoplasma gondii in small neotropical wild felids

    Directory of Open Access Journals (Sweden)

    William Alberto Cañon-Franco

    2013-02-01

    Full Text Available In the last decade, studies on wildlife worldwide have discovered key epidemiological aspects of the sylvatic cycle of Toxoplasma gondii. However, despite the known role of wild felines as definitive hosts in the transmission and maintenance of this parasite, few studies have focused on the involvement of these animals. Brazil exhibits the largest number of wild felid species in the Americas, all of which have a critical conservation status. However, serological detections, epidemiological studies and some molecular characterizations of T. gondii have primarily used Neotropical felid populations that are maintained in captivity, which does not reflect the disease behavior in free-living conditions. A systematic review of the worldwide scientific literature was conducted focusing on toxoplasmosis in small Neotropical felids. This review covered a number of aspects, including the state of scientific research, parasite transmission in the wild, the genetic characteristics of isolates, the relationship between these genetic characteristics and the pathogenicity of the parasite, and the risk factors linked to conflicts with humans. The present review shows the relevance of studying these felid populations based on their frequent interactions with humans in peri-urban areas and the need for further comprehensive studies to establish the real significance of T. gondii in public and animal health in tropical and temperate regions.

  8. Seroprevalence of Toxoplasma gondii in cats from Colombo, Sri Lanka

    Science.gov (United States)

    Cats are essential in the life cycle of Toxoplasma gondii because they are the only hosts that can excrete the environmentally-resistant oocysts in nature. Nothing is known of the prevalence of Toxoplasma gondii in cats from Sri Lanka. Serum samples from 86 cats from Colombo, Sri Lanka were tested f...

  9. IgA antibodies to Toxoplasma gondii in human tears

    NARCIS (Netherlands)

    Meek, B.; Klaren, V.N.A.; Haeringen, van N.J.; Kijlstra, A.; Peek, R.

    2000-01-01

    PURPOSE. To investigate whether mucosal immune responses directed against the ubiquitous parasite Toxoplasma gondii can be detected in tears of healthy humans. METHODS. Nonstimulated tears and blood were obtained from 62 healthy humans (mean age, 35 ± 10 [SD] years). Serum anti-T. gondii

  10. Antibodies to Toxoplasma gondii in Backyard and Wandering Pigs ...

    African Journals Online (AJOL)

    The objective of this study was to investigate the occurrence of antibodies to Toxoplasma gondii in backyard and wandering pigs slaughtered for human consumption in Ibadan, Southwestern Nigeria. Serum samples were collected from 100 pigs and tested for the presence of IgG Toxoplasma gondii-specific antibodies ...

  11. Seroprevalence of Toxoplasma gondii infection in Norwegian dairy goats

    Directory of Open Access Journals (Sweden)

    Stormoen Marit

    2012-12-01

    Full Text Available Abstract Background Toxoplasma gondii is a major problem for the sheep industry as it may cause reproduction problems. The importance of T. gondii in Norwegian goat herds is uncertain, but outbreaks of toxoplasmosis in dairy goat farms have been recorded. The aim of this study was to describe the prevalence of T. gondii infection in Norwegian dairy goats by using serology. Findings Goat serum originally collected as part of two nationwide surveillance and control programmes between 2002 and 2008 were examined for T. gondii antibodies by using direct agglutination test. In total, 55 of 73 herds (75% had one or more serologically positive animals, while 377 of 2188 (17% of the individual samples tested positive for T. gondii antibodies. Conclusions This is the first prevalence study of T. gondii infection in Norwegian goats. The results show that Norwegian goat herds are commonly exposed to T. gondii. Nevertheless, the majority of goat herds have a low prevalence of antibody positive animals, which make them vulnerable to infections with T. gondii during the gestation period.

  12. Prevalence of Toxoplasma gondii in common moles (Talpa europaea)

    NARCIS (Netherlands)

    Krijger, I.M.; Cornelissen, J.B.W.J.; Wisselink, H.J.; Meerburg, B.G.

    2014-01-01

    Background The prevalence of Toxoplasma gondii in common moles, Talpa europaea, was investigated in order to determine whether moles can serve as an indicator species for T. gondii infections in livestock. Findings In total, 86 moles were caught from 25 different sites in the Netherlands. Five

  13. On the determination of Toxoplasma gondii virulence in mice

    Science.gov (United States)

    Toxoplasma gondii is one of the most successful pathogens on earth, capable of infecting mammals and birds. Numerous papers and reports are published on isolation of T .gondii from various natural sources worldwide. The house mouse (Mus musculus) has been used as the laboratory animal model to deter...

  14. Experimental toxoplasma gondii infection in grey seals (Halichoerus grypus)

    DEFF Research Database (Denmark)

    Gajadhar, A. A.; Measures, L.; Forbes, L. B.

    2004-01-01

    or muscle tissue collected from inoculated seals passed T. gondii oocysts in feces. This study demonstrates that T. gondii oocysts can establish viable infection in seals and supports the hypothesis that toxoplasmosis in marine mammals can be acquired from oocysts in surface water runoff and sewer discharge....

  15. Toxoplasma gondii seroprevalence in dairy and beef cattle

    DEFF Research Database (Denmark)

    Jokelainen, Pikka; Tagel, Maarja; Motus, Kerli

    2017-01-01

    Toxoplasma gondii is a zoonotic protozoan parasite that thrives in Estonia. In this nationwide cross-sectional study, we tested sera from 3991 cattle, collected from 228 farms in 2012–2013, for anti-T. gondii immunoglobulin G antibodies using a commercial direct agglutination test. Titer of 100 w...

  16. Seroprevalence of Toxoplasma gondii infection in slaughtered pigs ...

    African Journals Online (AJOL)

    Toxoplasmosis is a parasitic disease/infection of medical and veterinary importance. The causative agent; Toxoplasma gondii, can infect warm blooded animals, birds as well as humans. This study was designed to determine the seroprevalence of Toxoplasma gondii infection in slaughtered pigs in Makurdi, Nigeria.

  17. Seroprevalence of Toxoplasma gondii and Neospora caninum in ...

    African Journals Online (AJOL)

    Background: Toxoplasma gondii and Neospora caninum are protozoans infecting a wide range of mammals; the etiologic agents of Toxoplasmosis and Neosporosis respectively, This study investigated the prevalence of antibodies to Toxoplasma gondii and Neospora caninum in dogs from southwestern Nigeria. Materials ...

  18. Seroprevalence of Toxoplasma gondii and potential risk factors in ...

    African Journals Online (AJOL)

    Toxoplasma gondii infection is important in pigs and humans may get infected through the consumption of undercooked infected pork. This study conducted in Oyo state, Nigeria for 15 months (between February, 2012 and April, 2013) investigated the seroprevalence of Toxoplasma gondii infection in pigs reared on farms ...

  19. Increased apoptosis skull of pups born to Toxoplasma gondii ...

    African Journals Online (AJOL)

    Background: Toxoplasma gondii is an intracellular obligate protozoan parasite that infects most warm-blooded animals including humans. It can cause congenital infection with clinical symptoms ranging from mild to severe including microcephaly. At the cellular level, infection T. gondii causes apoptosis in some tissues and ...

  20. Cloning and Sequencing of Truncated Toxoplasma gondii Subtilisin-Like 1 Antigen

    Directory of Open Access Journals (Sweden)

    Ahmad Rouhizadeh

    2016-07-01

    Full Text Available Background Toxoplasma gondii is an obligate intracellular protozoan parasite which has significant medical and veterinary impact on all around the world. Tracking of specific antigens or antibodies for toxoplasmosis is the main choice in its diagnosis. Recombinant proteins will improve sensitivity and specificity and reduce problems of standardization and reproducibility of diagnostic kits. Toxoplasma gondii Subtilisin-like protein (TgSUB1 is a novel example of a glycosylphosphatidylinositol GPI (-anchored protein which can be considered as a potential marker for serodiagnosis of toxoplasmosis. Objectives The aims of this study were to find out major antigenic parts of this whole protein and to develop a recombinant prokaryotic plasmid. Methods In this experimental study, using bioinformatics softwares Parker Hydrophilicity prediction and Bepipred linear Epitope prediction to select best highly antigenic region of this protein, a 744 bp fragment was amplified by polymerase chain reaction (PCR on cDNA obtained from T. gondii RNA. The PCR product was cloned in PCR2.1 vector and subcloned into expression pET28a vector. The PCR2.1-SUB1 and PET28a-SUB1constructs were analyzed by PCR, restriction analysis and sequencing. Results A highly antigenic region in the hydrophilic part of the protein including amino acid residues 549 to 795 was successfully cloned and the sequences were confirmed. All nucleotide sequences in the PCR product have 100% homology with the published reference sequence. Conclusions Pairing bioinformatics tools and cloning of the candidate molecules in vaccine development studies and diagnostic approaches will have powerful impact on promotion of research in infectious diseases. This strategy is considered as available and inexpensive technology even in less developed countries where the infectious diseases like toxoplasmosis is prevalent.

  1. Vaccines against Toxoplasma gondii: new developments and perspectives.

    Science.gov (United States)

    Zhang, Nian-Zhang; Chen, Jia; Wang, Meng; Petersen, Eskild; Zhu, Xing-Quan

    2013-11-01

    Toxoplasmosis caused by the protozoan Toxoplasma gondii is a major public health problem, infecting one-third of the world human beings, and leads to abortion in domestic animals. A vaccine strategy would be an ideal tool for improving disease control. Many efforts have been made to develop vaccines against T. gondii to reduce oocyst shedding in cats and tissue cyst formation in mammals over the last 20 years, but only a live-attenuated vaccine based on the S48 strain has been licensed for veterinary use. Here, the authors review the recent development of T. gondii vaccines in cats, food-producing animals and mice, and present its future perspectives. However, a single or only a few antigen candidates revealed by various experimental studies are limited by only eliciting partial protective immunity against T. gondii. Future studies of T. gondii vaccines should include as many CTL epitopes as the live attenuated vaccines.

  2. Evaluation of the immune response in BALB/c mice induced by a novel DNA vaccine expressing GRA14 against Toxoplasma gondii.

    Science.gov (United States)

    Ahmadpour, E; Sarvi, S; Hashemi Soteh, M B; Sharif, M; Rahimi, M T; Valadan, R; Tehrani, M; Khalilian, A; Montazeri, M; Daryani, A

    2017-04-01

    Toxoplasma gondii can cause severe and even fatal disease in human beings and animals. Effective vaccines may contribute to control toxoplasmosis. GRA14, a novel secreted dense granule protein of T. gondii, has been proposed as a vaccine candidate due to its intervacuolar transport and unique topology in the parasitophorous vacuole membrane. In this study, we constructed a DNA vaccine encoding GRA14 of T. gondii. BALB/c mice were immunized intramuscularly three times at 2 week intervals and challenged with T. gondii RH strain 5 weeks later. The immune responses were evaluated using lymphocyte proliferation assay, cytokine and antibody measurements. In addition, the survival times and parasite load of mice challenged with the virulent T. gondii RH strain were evaluated. The results showed that the mice immunized with pcGRA14 induced both enhanced specific humoral and Th1 cellular immune responses, and also mice immunized with the pcGRA14 showed an increased survival time and decreased parasite load compared with control groups (P<.05). The results indicated, for the first time, that the GRA14 is a potential DNA vaccine against toxoplasmosis. © 2017 John Wiley & Sons Ltd.

  3. Isolation and Genotyping of Toxoplasma gondii in Brazilian Dogs

    Science.gov (United States)

    da Silva, Jamille Rodrigues; Maciel, Bianca Mendes; de Santana Souza Santos, Luana Karla Nogueira; Carvalho, Fábio Santos; de Santana Rocha, Daniele; Lopes, Carlos Wilson Gomes; Albuquerque, George Rêgo

    2017-01-01

    Strains of Toxoplasma gondii in Brazil are highly genetically diverse compared to strains from North America and Europe. Dogs are epidemiologically important because they act as sentinels for T. gondii infections in humans and are good indicators of environmental contamination. The aim of this study was to isolate and genetically characterize T. gondii strains from tissues of naturally infected Brazilian dogs. For this study, 21 blood samples were collected from dogs at the Zoonosis Control Centers of Ilhéus and Itabuna cities, Bahia, Brazil. The sera were examined for T. gondii antibodies using the indirect hemagglutination test. Brains and hearts of seropositive dogs were bioassayed in mice to isolate and characterize T. gondii parasites by PCR-RFLP using 10 genetic markers (SAG1, newSAG2, SAG3, BTUB, c22-8, c29-2, GRA6, PK1, APICO, and L358). However, T. gondii was isolated from only 4 (57.1%) dogs, designated TgDgBr6, 13, 17, and 21. All strains were virulent, causing clinical changes (rough hair coat, lethargy, and abdominal distention) and the death of all mice within 8–20 days after inoculation. Genetic analysis of these 4 T. gondii isolates revealed 4 distinct genotypes with different clonal lineage combinations (types I, II, and III) and 2 atypical alleles. Using PCR-RFLP with several markers, this study contributes to evaluations of the genetic diversity of strains circulating in Brazil. PMID:28719948

  4. High yield expression and single-step purification of Toxoplasma gondii SAG1, GRA1, and GRA7 antigens in Escherichia coli

    DEFF Research Database (Denmark)

    Hiszczynska-Sawicka, E.; Brillowska-Dabrowska, A.; Dabrowski, Slawomir

    2003-01-01

    This report describes a simple, highly efficient and reproducible method for obtaining large quantities of highly pure recombinant Toxoplasma gondii antigens, which can be used for diagnostic application. The obtained T gondii SAG1, GRA1, and GRA7 antigens (as fusion proteins), expressed...... in Escherichia coli, contained polyhistidine tags at the N- and C-ends that allowed single-step isolation by metal-affinity chromatography on Ni2+-IDA-Sepharose columns. The immunoreactivity of the recombinant antigens was tested in an enzyme-linked immunosorbent assay (ELISA) format for potential application...

  5. Evaluation of recombinant granule antigens GRA1 and GRA7 for serodiagnosis of Toxoplasma gondii infection in dogs.

    Science.gov (United States)

    Wang, Zedong; Ge, Wei; Huang, Si-Yang; Li, Jiping; Zhu, Xing-Quan; Liu, Quan

    2014-07-12

    Toxoplasmosis, caused by the obligate intracellular parasite Toxoplasma gondii, is an important zoonotic disease worldwide. The precise detection of T. gondii infection in dogs has important public health significance. In this study, recombinant granule antigen proteins GRA1 and GRA7 were evaluated as potential diagnostic markers for T. gondii infection in dogs by an indirect enzyme-linked immunosorbent assay (ELISA). GRA1 and GRA7 were cloned and expressed in Escherichia coli, and the recombinant GRA1, GRA7- and Toxoplasma lysate antigen (TLA)-based ELISAs were developed and evaluated using the canine positive and negative serum samples for anti-T. gondii antibodies determined by modified agglutination test (MAT) and indirect fluorescent antibody test (IFAT), showing a seroprevalence of 15.1% by TLA- and GRA1-ELISA, and 15.8% by GRA7-ELISA, and no significant difference was observed (P > 0.05). When compared with the two reference assays, MAT and IFAT, the GRA7-ELISA showed the highest co-positivity and co-negativity rates. Receiver operating characteristic (ROC) analysis revealed a largest area under curve (AUC) of 0.973 (95% CI, 0.955 to 0.991), and a highest relative sensitivity (93.2%) and specificity (94.0%) for a cut-off value of 0.809 in GRA7-ELISA. The results of the present study showed that GRA7-ELISA is highly sensitive and specific, and GRA7 is a potential serodiagnostic marker for the detection of T. gondii infection in dogs.

  6. Toxoplasma gondii antibodies in the white stork Ciconia ciconia.

    Science.gov (United States)

    Andrzejewska, Izabela; Tryjanowski, Piotr; Zduniak, Piotr; Dolata, Pawel T; Ptaszyk, Jerzy; Cwiertnia, Piotr

    2004-01-01

    The prevalence of Toxoplasma gondii in chicks of wild birds and captive individuals was studied in the Poznań environs and in the Poznań Zoological Garden in the years 2002-2003. Bird blood was tested for T. gondii antibodies by an indirect fluorescent antibody test. T. gondii antibodies were detected from 5.8% of 205 analysed white stork chicks and 13.6% of 44 analysed adult storks in the zoo. Because toxoplasmosis is one of the more common parasitic zoonoses worldwide, we briefly discuss the potential epidemiological importance of stork toxoplasmosis to humans.

  7. Intranasal immunisation with recombinant Toxoplasma gondii actin partly protects mice against toxoplasmosis.

    Directory of Open Access Journals (Sweden)

    Li-Tian Yin

    Full Text Available Toxoplasma gondii is a ubiquitous protozoan intracellular parasite, the causative agent of toxoplasmosis, and a worldwide zoonosis for which an effective vaccine is needed. Actin is a highly conserved microfilament protein that plays an important role in the invasion of host cells by T. gondii. This study investigated the immune responses elicited by BALB/c mice after nasal immunisation with a recombinant T. gondii actin (rTgACT and the subsequent protection against chronic and lethal T. gondii infections. We evaluated the systemic response by proliferation, cytokine and antibody measurements, and we assessed the mucosal response by examining the levels of TgACT-specific secretory IgA (SIgA in nasal, vaginal and intestinal washes. Parasite load was assessed in the liver and brain, and the survival of mice challenged with a virulent strain was determined. The results showed that the mice immunised with rTgACT developed high levels of specific anti-rTgACT IgG titres and a mixed IgG1/IgG2a response with a predominance of IgG2a. The systemic immune response was associated with increased production of Th1 (IFN-γ and IL-2, Th2 (IL-4 and Treg (IL-10 cytokines, indicating that not only Th1-type response was induced, but also Th2- and Treg-types responses were induced, and the splenocyte stimulation index (SI was increased in the mice immunised with rTgACT. Nasal immunisation with rTgACT led to strong mucosal immune responses, as seen by the increased secretion of SIgA in nasal, vaginal and intestinal washes. The vaccinated mice displayed significant protection against lethal infection with the virulent RH strain (survival increased by 50%, while the mice chronically infected with RH exhibited lower liver and brain parasite loads (60.05% and 49.75%, respectively than the controls. Our data demonstrate, for the first time, that actin triggers a strong systemic and mucosal response against T. gondii. Therefore, actin may be a promising vaccine candidate

  8. Intranasal immunisation with recombinant Toxoplasma gondii actin partly protects mice against toxoplasmosis.

    Science.gov (United States)

    Yin, Li-Tian; Hao, Hai-Xia; Wang, Hai-Long; Zhang, Jian-Hong; Meng, Xiao-Li; Yin, Guo-Rong

    2013-01-01

    Toxoplasma gondii is a ubiquitous protozoan intracellular parasite, the causative agent of toxoplasmosis, and a worldwide zoonosis for which an effective vaccine is needed. Actin is a highly conserved microfilament protein that plays an important role in the invasion of host cells by T. gondii. This study investigated the immune responses elicited by BALB/c mice after nasal immunisation with a recombinant T. gondii actin (rTgACT) and the subsequent protection against chronic and lethal T. gondii infections. We evaluated the systemic response by proliferation, cytokine and antibody measurements, and we assessed the mucosal response by examining the levels of TgACT-specific secretory IgA (SIgA) in nasal, vaginal and intestinal washes. Parasite load was assessed in the liver and brain, and the survival of mice challenged with a virulent strain was determined. The results showed that the mice immunised with rTgACT developed high levels of specific anti-rTgACT IgG titres and a mixed IgG1/IgG2a response with a predominance of IgG2a. The systemic immune response was associated with increased production of Th1 (IFN-γ and IL-2), Th2 (IL-4) and Treg (IL-10) cytokines, indicating that not only Th1-type response was induced, but also Th2- and Treg-types responses were induced, and the splenocyte stimulation index (SI) was increased in the mice immunised with rTgACT. Nasal immunisation with rTgACT led to strong mucosal immune responses, as seen by the increased secretion of SIgA in nasal, vaginal and intestinal washes. The vaccinated mice displayed significant protection against lethal infection with the virulent RH strain (survival increased by 50%), while the mice chronically infected with RH exhibited lower liver and brain parasite loads (60.05% and 49.75%, respectively) than the controls. Our data demonstrate, for the first time, that actin triggers a strong systemic and mucosal response against T. gondii. Therefore, actin may be a promising vaccine candidate against

  9. Structuraland antigenic analysis of a new Rhoptry Pseudokinase Gene (ROP54) in Toxoplasma gondii.

    Science.gov (United States)

    Zhou, Jian; Lu, Gang; Wang, Lin; Zhou, Aihua H; Han, Yali L; Guo, Jingjing J; Song, Pengxia X; Zhou, Huaiyu Y; Cong, Hua; Hou, Ming; He, Shenyi Y

    2017-09-26

    Toxoplasma gondii is defined as an obligate intracellular apicomplexan parasite and influences approximatelyone-third of the human all over the world. ROP54 protein is expressed in the rhoptry of Toxoplasma gondii. In the present study, we used SMART software to analyzethe secondary structure of ROP54. The 3D model of ROP54 protein was constructed and analyzed using SWISS-MODEL server and VMD software. The structure results fully showed that ROP54 proteinis an importantmember from the ROP family. Moreover, DNAMAN software and Epitope Database online service were used to analyze liner-B cell epitopes and Th-cell epitopes of the protein. The bioinformatics prediction of ROP54 protein could provide positive information on treatment and vaccine for toxoplasmosis. Furthermore, ROP54 gene was obtained from PCR, and a recombinant eukaryotic expression vector (pEGFP-ROP54) was constructed in the following study. After identification of enzyme digestion, the constructed plasmid was transfected into HEK 293-T cells. The RT-PCR result suggested that the recombinant plasmid could transcribe successfully in HEK 293-T cell.

  10. Fatal Toxoplasma gondii infection in the giant panda

    Directory of Open Access Journals (Sweden)

    2015-01-01

    Full Text Available Toxoplasma gondii can infect nearly all warm-blooded animals. We report an acute fatal T. gondii infection in the endangered giant panda (Ailuropoda melanoleuca in a zoo in China, characterized by acute gastroenteritis and respiratory symptoms. T. gondii infection was confirmed by immunological and molecular methods. Multilocus nested PCR-RFLP revealed clonal type I at the SAG1 and c29-2 loci, clonal type II at the SAG2, BTUB, GRA6, c22-8, and L358 loci, and clonal type III at the alternative SAG2 and SAG3 loci, thus, a potential new genotype of T. gondii in the giant panda. Other possible pathogens were not detected. To our knowledge, this is the first report of clinical toxoplasmosis in a giant panda.

  11. Outbreak of caprine abortion by Toxoplasma gondii in Midwest Brazil

    Directory of Open Access Journals (Sweden)

    Flávio Henrique Bravim Caldeira

    2011-11-01

    Full Text Available An outbreak of abortion by Toxoplasma gondii in goats on a farm in the Brazilian Midwest is reported. Gross lesions were not observed in seven aborted fetuses submitted to the Veterinary Pathology Laboratory, Federal University of Mato Grosso, for necropsy investigation. The main histologic lesions were mononuclear cell pneumonia and necrotizing encephalitis in varying degrees of intensity. PCR for Brucella abortus and Neospora caninum and aerobic cultures were negative in all cases. Antibody titles against T. gondii varying from 1:1024 to 1:32.768 were detected in serum samples from four aborted goats. Nested-PCR assay for T. gondii were positive in brain samples of all cases submitted. These findings indicate that T. gondii infection should be considered in the diagnosis of abortion in goats in Midwest Brazil.

  12. ISOLATION OF PURIFIED OOCYST WALLS AND SPOROCYSTS FROM TOXOPLASMA GONDII

    Science.gov (United States)

    Toxaplasma gondii is a parasitic protozoan that infects a wide range of vertebrates, including humans. This report describes methods that have been developed for separation of oocyst components starting with the mechanical fragmentation of oocysts. Use of iodixoanol gradients a...

  13. Seroprevalence of Toxoplasma gondii in donkeys (Equus asinus) in Italy.

    Science.gov (United States)

    Machacova, Tereza; Bartova, Eva; Di Loria, Antonio; Sedlak, Kamil; Mariani, Ugo; Fusco, Giovanna; Fulgione, Domenico; Veneziano, Vincenzo; Dubey, Jitender P

    2014-03-01

    Toxoplasmosis, an important zoonosis, can be transmitted by eating meat or drinking milk of animals infected with Toxoplasma gondii. Samples were collected from 238 donkeys in the year 2010 in Italy, which included 207 females and 31 males of five breeds and crossbreeds with the average age 9 years (1 month-24 years). Sera were tested for T. gondii antibodies using a latex agglutination test and the indirect fluorescent antibody test; 5 and 8% seropositivity were recorded, respectively. We found significant correlation between the presence of T. gondii antibodies and sex, age, grazing and presence of cats on the farms and their access to donkey feed. This is the first detection of T. gondii antibodies in donkeys in Italy.

  14. Cloning of Dense Granular (GRA 7 Gene of Toxoplasma gondii into pTZ57RT Vectors for Sub-Cloning in Prokaryotic and Eukaryotic Plasmids

    Directory of Open Access Journals (Sweden)

    Zahra Arab-Mazar

    2014-11-01

    Full Text Available Background: Serological assay based on dense granular (GRA proteins of Toxoplasma gondii (T. gondii is actually the most popular laboratory diagnostic tool to detection of toxoplasmosis. We aimed to construct a recombinant GRA7-pTZ57RT plasmid vectors that it is suitable for sub-cloning and GRA7 protein production.Materials and Methods: Souris mice were used for maintaining of T. gondii tachyzoites by serial intraperitoneal passage. The tachyzoites’ DNA was extracted, and the GRA7 gene was amplified by PCR. The purified DNA was inserted into pTZ57RT cloning vectors, and then transformed into TOP10 competent cells. Finally, cloning and transformation were confirmed by restriction enzymatic digestion and gene sequencing.Results: Agarose gel electrophoresis analysis on PCR products of genomic DNA, revealed 726 bp bands that were equal to the GRA7 gene. Both white (recombinant and blue (non-recombinant colonies appeared on ampicillin-LB agar. Results of enzymatic digestion and gene sequencing confirmed successful cloning and transformation procedures.Conclusion: The GRA7 gene of T. gondii was cloned into pTZ57RT plasmid, which is suggested to be further used as DNA vaccine or sub-cloned for production of recombinant GRA7 protein.

  15. Is Toxoplasma gondii infection protective against multiple sclerosis risk?

    Science.gov (United States)

    Koskderelioglu, Asli; Afsar, Ilhan; Pektas, Bayram; Gedizlioglu, Muhtesem

    2017-07-01

    Parasitic infections may play a protective role in neurodegenative diseases. OBJECTıVE: To determine the association between Toxoplasma gondii (T. gondii) infection and Multiple Sclerosis (MS). One hundred fifteen patients with MS were included in the study. Sixty age and gender-matched healthy subjects were recruited as controls. Subjects were assessed for clinical and demographic parameters. The presence of specific IgG antibodies against T. gondii microorganism was searched by using an enzyme immunoassay test in the sera of the subjects. T. gondii seropositivity was found to be lower in MS patients than in healthy controls (33.9% vs. 55%, p=0.007). Mean age and disease duration of the patients were 41.15±11.20 (18-74) and 1.90±1.44 (0-6) years, respectively. MS patients with a high IgG titer had lower expanded disability status scale (EDSS) scores (p=0.001) and lower annualized relapse rates (ARR) (p=0.005). There was no significant association between T. gondii seropositivity and disease duration (p=0.598). Female MS patients tended to have higher T. gondii seropositivity than males although the difference did not reach statistical significance (p=0.192). We found a negative correlation between T. gondii seropositivity and both EDSS scores (r=-0.322, p<0.001) and ARR (r=-0.263, p=0.004). CONCLUSıON: We found a negative association between T. gondii infection and the presence of MS. Furthermore, parasite infected MS patients had experienced fewer relapses with lower disability scores supporting the hypothesis of immunomodulatory effects of parasitic infections in autoimmune diseases. Further studies are required to establish the protective role of parasitic infections in MS. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Movement of Toxoplasma gondii Oocysts in Unsaturated Natural Soils

    Science.gov (United States)

    Kinsey, Erin; Korte, Caroline; L'Ollivier, Coralie; Dubey, Jitender; Dumetre, Aurélien; Darnault, Christophe

    2017-04-01

    Toxoplasma gondii has a complex lifecycle that involves a wide variety of intermediate hosts with felids as the definitive host. Because of its numerous hosts and the prevalence of cats, T.gondii has spread throughout nearly the entire globe. Oocysts have been found not only in the feces of cats, but also in soils, animal feeds and water. Exposure through consumption of infected meat or following contact with cat feces can cause damage to the eyes, brain and other organs of immunocompromised populations as well as fetuses if they are exposed in utero. The prevalence of T.gondii and potential health risks necessitate a better understanding of the transport of T.gondii through soils, which to this point has not been well studied. This work aims to characterize the transport and retention of T.gondii oocysts in a number of unsaturated natural soils where fast transport and preferential flow paths have been prevented. The soils used are classified as loamy sands and sandy loams. They were placed in soil columns at a known bulk density and were then subjected to an artificial rain of 1 mM KCl solution. Flow in the columns was vertical and gravity driven. After steady state was reached, a pulse containing 2.5 million T.gondii oocysts and KBr as a conservative tracer was applied to the top of the column, after which steady rainfall was resumed. Leachate samples were collected throughout the experiment. qPCR for T.gondii was performed and KBr ions were measured to create breakthrough curves for both. After the completion of the rainfall portion of the experiment, soil columns were cut into 1 to 2 cm sections and analyzed for T.gondii with qPCR to characterize retention within the column and for soil water content.

  17. Toxoplasma gondii infection and chronic schizophrenia: is there any association?

    Directory of Open Access Journals (Sweden)

    Salvina Maria de Campos-Carli

    Full Text Available ABSTRACT Background: Toxoplasma gondii (T. gondii infection has been identified as a risk factor for schizophrenia. Objectives: Herein, we sought to evaluate the association between T. gondii infection and clinical symptoms and quality of life in patients with schizophrenia. Methods: We conducted a cross-sectional study with 48 patients with chronic schizophrenia and 40 controls. Peripheral blood was drawn, and IgM and IgG anti-T. gondii antibodies were evaluated by Enzyme-Linked Immunosorbent Assay (ELISA. Depressive, positive and negative symptoms were assessed, respectively, by the Calgary Depression Scale (CDS and the Positive and Negative Syndrome Scale (PANSS. Cognitive performance was assessed in patients by the Brazilian version of the Schizophrenia Cognition Rating Scale (SCoRS-BR. Quality of life was assessed by the Brazilian version of the Quality of Life in Schizophrenia scale (QLS-BR. Results: The prevalence and titers of T. gondii IgM and IgG antibodies did not differ between patients and controls. The positive serology for T. gondii IgG antibodies was not associated with illness symptoms, cognitive performance, depressive symptoms or quality of life. Discussion: Our findings suggest that toxoplasmosis infection is not associated with severity of symptoms, quality of life, cognitive or depressive symptoms in schizophrenia patients.

  18. Seroprevalence of Toxoplasma gondii in wild kangaroos using an ELISA.

    Science.gov (United States)

    Parameswaran, N; O'Handley, R M; Grigg, M E; Fenwick, S G; Thompson, R C A

    2009-06-01

    Infection with Toxoplasma gondii is a significant problem in Australian marsupials, and can lead to devastating disease and predispose animals to predation. T. gondii infection in kangaroos is also of public health significance due to the kangaroo meat trade. A moderate seroprevalence of T. gondii was observed in a study of western grey kangaroos located in the Perth metropolitan area in Western Australia. Of 219 kangaroos tested, 15.5% (95%CI: 10.7-20.3) were positive for T. gondii antibodies using an ELISA developed to detect T. gondii IgG in macropod marsupials. When compared with the commercially available MAT (modified agglutination test), the ELISA developed was in absolute agreement and yielded a kappa coefficient of 1.00. Of 18 kangaroos tested for the presence of T. gondii DNA by PCR, the 9 ELISA positive kangaroos tested PCR positive and the 9 ELISA negative kangaroos tested PCR negative indicating the ELISA protocol was both highly specific and sensitive and correlated 100% with the more labour intensive PCR assay.

  19. Experimental Toxoplasma gondii infection in striped skunk (Mephitis mephitis).

    Science.gov (United States)

    Quirk, Travis; Dubey, J P

    2008-06-01

    Twenty-three striped skunks (Mephitis mephitis) without demonstrable antibodies in 1:25 serum dilution in the modified agglutination test (MAT) were fed sporulated Toxoplasma gondii oocysts (9 skunks) or tissue cysts (10 skunks), and 4 skunks (controls) were not fed T. gondii. Skunks were bled before feeding T. gondii, 10 and 23- 25 days postinoculation (PI). All 9 seronegative skunks fed oocysts died of acute toxoplasmosis between 7 and 19 days PI; T. gondii tachyzoites were found in histological sections of many tissues. One of the 10 skunks fed tissue cysts and 1 of the 4 controls also died of acute toxoplasmosis days 19 and 20 PI; these animals probably became infected by ingestion of unexcysted oocysts passed in feces of skunks fed oocysts that were housed in the same room that skunks fed tissue cysts were housed. The remaining 9 skunks fed tissue cysts and the 3 controls developed only a mild illness and were killed in good health on days 23-25 PI. Antibodies to T. gondii were not found in 1:25 serum dilution of any of the 19 of 23 skunks that were alive on day 10 PI; 12 of 13 skunks had antibodies (MAT 1:80 or higher) on the day they were killed. Antibodies were not found in 1 skunk. Results indicate that skunks can develop IgG antibodies to T. gondii within 3 wk PI, and primary toxoplasmosis can be fatal in skunks.

  20. Diagnosis of toxoplasmosis and typing of Toxoplasma gondii.

    Science.gov (United States)

    Liu, Quan; Wang, Ze-Dong; Huang, Si-Yang; Zhu, Xing-Quan

    2015-05-28

    Toxoplasmosis, caused by the obligate intracellular protozoan Toxoplasma gondii, is an important zoonosis with medical and veterinary importance worldwide. The disease is mainly contracted by ingesting undercooked or raw meat containing viable tissue cysts, or by ingesting food or water contaminated with oocysts. The diagnosis and genetic characterization of T. gondii infection is crucial for the surveillance, prevention and control of toxoplasmosis. Traditional approaches for the diagnosis of toxoplasmosis include etiological, immunological and imaging techniques. Diagnosis of toxoplasmosis has been improved by the emergence of molecular technologies to amplify parasite nucleic acids. Among these, polymerase chain reaction (PCR)-based molecular techniques have been useful for the genetic characterization of T. gondii. Serotyping methods based on polymorphic polypeptides have the potential to become the choice for typing T. gondii in humans and animals. In this review, we summarize conventional non-DNA-based diagnostic methods, and the DNA-based molecular techniques for the diagnosis and genetic characterization of T. gondii. These techniques have provided foundations for further development of more effective and accurate detection of T. gondii infection. These advances will contribute to an improved understanding of the epidemiology, prevention and control of toxoplasmosis.

  1. New findings: depression, suicide, and Toxoplasma gondii infection.

    Science.gov (United States)

    Hsu, Pao-Chu; Groer, Maureen; Beckie, Theresa

    2014-11-01

    This article provides an overview of the evidence of a potential pathophysiological relationship between depression, suicide, and the Toxoplasma gondii (T. gondii) infection. It discusses the role of inflammatory processes in depressive illness and the infection theory of psychiatric disease. It also provides guidelines for the screening, diagnosis, and treatment of depression for nurse practitioners (NPs). A narrative review was conducted of the literature from PubMed, PsycINFO, and Google Scholar. References of identified articles were also reviewed. Seropositivity of the obligate intracellular protozoan parasite, T. gondii is related to various mental health disorders including schizophrenia, suicide attempt, depression, and other neuropsychiatric diseases. Depressive symptoms have been linked to interferon-γ (IFN-γ) blocking T. gondii growth by inducing indoleamine-2,3-dioxygenase (IDO) activation and tryptophan depletion, which results in a decrease of serotonin production in the brain. Although exposure to T. gondii was considered unlikely to reactivate in immune-competent individuals, new findings report that this reactivation may be triggered by immune imbalance. NPs caring for patients with psychiatric illness need to understand the potential mechanisms associated with depression and the T. gondii infection in order to provide effective screening, treatment, and disease prevention. ©2014 American Association of Nurse Practitioners.

  2. Evaluating Recombinant Antigen ROP1 Efficacy in Diagnosis of Toxoplasma Gondii Infection

    Directory of Open Access Journals (Sweden)

    F Keshavarzi

    2015-07-01

    Full Text Available Introduction:Toxoplasma gondii is a ubiquitous obligate intracellular parasite with a relatively broad host range infecting both mammals and birds. Toxoplasma proteins are strong antigens that can begin strong immune reactions, among which Rhoptry protein 1 (ROP1 can be named discharging from rhoptry cell-organ. ROP1 is regarded as a competitor for recombinant vaccines against toxoplasmosis. Therefore, the main objective of the current study was to evaluate the cloning and expression of ROP1 Toxoplasma gondii in a cloning vector as well as to create this recombinant antigen in order to be applied for later uses. Methods:Genomic DNA of Toxoplasma gondii was removed and reproduced by PCR, then the PCR product was cloned into the EcoR1 and BamH1 sites of cloning vector, pUET1, and transformed into Escherichia coli BL21 plysS strain. Moreover, pcROP1 was sub-cloned into the HindIII and EcoRI sites of the pcDNA3 in order to produce recombining eukaryotic declaration vector. The cloned ROP1 was verified by PCR, limitation enzymes (HindIII and BglΙ digestion and nucleotide sequencing. Then, this recombinant antigen was covered applying IgM and ELISAIgG. Results:The study results demonstrated that a fragment of 757 bp was separated. In addition, nucleotide sequence analysis of the ROP1 cloned in pUET1vector revealed high homology (96% with RH strain Gene Bank Accession (No. M71274. Conclusion:The recombinant ROP1 antigen in an IgM Rec-ELISA test can be replaced with the tachyzoite antigen in IgG and IgM serologic tests.

  3. Cytoskeletal Components of an Invasion Machine—The Apical Complex of Toxoplasma gondii

    Science.gov (United States)

    Hu, Ke; Johnson, Jeff; Florens, Laurence; Fraunholz, Martin; Suravajjala, Sapna; DiLullo, Camille; Yates, John; Roos, David S; Murray, John M

    2006-01-01

    The apical complex of Toxoplasma gondii is widely believed to serve essential functions in both invasion of its host cells (including human cells), and in replication of the parasite. The understanding of apical complex function, the basis for its novel structure, and the mechanism for its motility are greatly impeded by lack of knowledge of its molecular composition. We have partially purified the conoid/apical complex, identified ~200 proteins that represent 70% of its cytoskeletal protein components, characterized seven novel proteins, and determined the sequence of recruitment of five of these proteins into the cytoskeleton during cell division. Our results provide new markers for the different subcompartments within the apical complex, and revealed previously unknown cellular compartments, which facilitate our understanding of how the invasion machinery is built. Surprisingly, the extreme apical and extreme basal structures of this highly polarized cell originate in the same location and at the same time very early during parasite replication. PMID:16518471

  4. Mechanisms of Toxoplasma gondii persistence and latency

    Science.gov (United States)

    Sullivan, William J.; Jeffers, Victoria

    2011-01-01

    Toxoplasma gondii is an obligate intracellular protozoan parasite that causes opportunistic disease, particularly in immunocompromised individuals. Central to its transmission and pathogenesis is the ability of the proliferative stage (tachyzoite) to convert into latent tissue cysts (bradyzoites). Encystment allows Toxoplasma to persist in the host, and affords the parasite a unique opportunity to spread to new hosts without proceeding through its sexual stage, which is restricted to felids. Bradyzoite tissue cysts can cause reactivated toxoplasmosis if host immunity becomes impaired. A greater understanding of the molecular mechanisms orchestrating bradyzoite development is needed to better manage the disease. Here we will review key studies that have contributed to our knowledge about this persistent form of the parasite and how to study it, with a focus on how cellular stress can signal for the reprogramming of gene expression needed during bradyzoite development. PMID:22091606

  5. Toxoplasma gondii impairs memory in infected seniors.

    Science.gov (United States)

    Gajewski, Patrick D; Falkenstein, Michael; Hengstler, Jan G; Golka, Klaus

    2014-02-01

    Almost 30% of humans present a Toxoplasma gondii positive antibody status and its prevalence increases with age. The central nervous system is the main target. However, little is known about the influence of asymptomatic i.e. latent Toxoplasmosis on cognitive functions in humans. To investigate neurocognitive dysfunctions in asymptomatic older adults with T. gondii positive antibody status a double-blinded neuropsychological study was conducted. The participants were classified from a population-based sample (N=131) of healthy participants with an age of 65 years and older into two groups with 42 individuals each: Toxoplasmosis positive (T-pos; IgG>50 IU/ml) and Toxoplasmosis negative (T-neg; IgG=0 IU/ml). The outcome measures were a computer-based working-memory test (2-back) and several standardized psychometric tests of memory and executive cognitive functions. T-pos seniors showed an impairment of different aspects of memory. The rate of correctly detected target symbols in a 2-back task was decreased by nearly 9% (P=0.020), corresponding to a performance reduction of about 35% in working memory relative to the T-neg group. Moreover, T-pos seniors had a lower performance in a verbal memory test, both regarding immediate recall (10% reduction; P=0.022), delayed recognition (6%; P=0.037) and recall from long-term memory assessed by the word fluency tests (12%; P=0.029). In contrast, executive functions were not affected. The effects remained mostly unchanged after controlling for medication. The impairment of memory functions in T-pos seniors was accompanied by a decreased self-reported quality of life. Because of the high prevalence of asymptomatic Toxoplasmosis and an increasing population of older adults this finding is of high relevance for public health. Copyright © 2013 Elsevier Inc. All rights reserved.

  6. Prevalence of Toxoplasma gondii and Neosport caninum antibodies in Spanish ibex (Capra pryenaica hispanica)

    Science.gov (United States)

    Wild felids are considered important in maintaining the sylvatic cycle of Toxoplasma gondii. Although, T. gondii antibodies have been reported in several species of wild felids, little is known of the epidemiology and risk factors associated with T. gondii infection in wild cats. The Iberian lynx (L...

  7. Seroprevalence and risk factors for Toxoplasma gondii infection in domestic cats in The Netherlands

    NARCIS (Netherlands)

    Opsteegh, M.; Haveman, R.; Swart, A.; Mensink-Beerepoot, M.E.; Hofhuis, A.; Langelaar, M.F.M.; van der Giessen, J.W.B.

    2012-01-01

    Cats, as definitive hosts, play an important role in the transmission of Toxoplasma gondii. To determine the seroprevalence and risk factors for T. gondii infection in Dutch domestic cats, serum samples of 450 cats were tested for T. gondii antibodies by indirect ELISA. Binary mixture analysis was

  8. Use of filter papers to determine seroprevalence of Toxoplasma gondii among hunted ungulates

    Science.gov (United States)

    Toxoplasmosis is a zoonosis caused by the protozoan Toxoplasma gondii, and it is found worldwide. To determine whether ungulates are reservoirs of T. gondii in an isolated and remote region of the northeastern Peruvian Amazon, antibodies to T. gondii were determined in 5 species of ungulates by the...

  9. High prevalence of Toxoplasma gondii antibodies in dogs in Veracruz, Mexico

    Science.gov (United States)

    Little is known concerning the prevalence of Toxoplasma gondii infection in dogs in Mexico. Here, we investigated antibodies to T. gondii and associated risk factors in 101 dogs from an animal shelter in Veracruz State, Mexico. Canine sera were assayed for T. gondii IgG antibodies by using the modif...

  10. Isolation and genetic characterization of Toxoplasma gondii from the gray wolf Canis lupus

    Science.gov (United States)

    Little is known of the genetic diversity of Toxoplasma gondii circulating in wildlife. In the present study feral gray wolf (Canis lupus) from Minnesota were examined for T. gondii infection. Antibodies to T. gondii were detected in 130 (52.4%) of 248 wolves tested by the modified agglutination test...

  11. Schizogony and gametogony of the vaccine, oocyst-deficient, strain T-263 of Toxoplasma gondii

    Science.gov (United States)

    Oocysts are important stage for the spread of Toxoplasma gondii because they are environmentally resistant. Among all hosts of T. gondii, only felids can excrete oocysts. Cats that have excreted T. gondii oocysts after primary infection become immune to re-excretion of oocysts, and this immunity app...

  12. Serotyping of Toxoplasma gondii in Cats (Felis domesticus) Reveals Predominance of Type II Infections in Germany

    Science.gov (United States)

    Background: Cats are definitive hosts of Toxoplasma gondii and play an essential role in the epidemiology of this parasite. The study aims at clarifying whether cats are able to develop specific antibodies against different clonal types of T. gondii and to determine by serotyping the T. gondii clona...

  13. Measuring tubulin content in Toxoplasma gondii: A comparison of laser-scanning confocal and wide-field fluorescence microscopy

    Science.gov (United States)

    Swedlow, Jason R.; Hu, Ke; Andrews, Paul D.; Roos, David S.; Murray, John M.

    2002-01-01

    Toxoplasma gondii is an intracellular parasite that proliferates within most nucleated cells, an important human pathogen, and a model for the study of human and veterinary parasitic infections. We used a stable yellow fluorescent protein-α-tubulin transgenic line to determine the structure of the microtubule cytoskeleton in T. gondii. Imaging of living yellow fluorescent protein-α-tubulin parasites by laser-scanning confocal microscopy (LSCM) failed to resolve the 22 subpellicular microtubules characteristic of the parasite cytoskeleton. To understand this result, we analyzed sources of noise in the LSCM and identified illumination fluctuations on time scales from microseconds to hours that introduce significant amounts of noise. We confirmed that weakly fluorescent structures could not be imaged in LSCM by using fluorescent bead standards. By contrast, wide-field microscopy (WFM) did visualize weak fluorescent standards and the individual microtubules of the parasite cytoskeleton. We therefore measured the fluorescence per unit length of microtubule by using WFM and used this information to estimate the tubulin content of the conoid (a structure important for T. gondii infection) and in the mitotic spindle pole. The conoid contains sufficient tubulin for ≈10 microtubule segments of 0.5-μm length, indicating that tubulin forms the structural core of the organelle. We also show that the T. gondii mitotic spindle contains ≈1 microtubule per chromosome. This analysis expands the understanding of structures used for invasion and intracellular proliferation by an important human pathogen and shows the advantage of WFM combined with image deconvolution over LSCM for quantitative studies of weakly fluorescent structures in moderately thin living cells. PMID:11830634

  14. Effects of ionizing radiation over the structure, metabolism and infectivity of a pathogenic protozoan, Toxoplasma gondii

    International Nuclear Information System (INIS)

    Hiramoto, Roberto Mitsuyoshi

    1998-01-01

    The intracellular parasite Toxoplasma gondii (Apicomplexa), has as definitive host domestic and wild felines and as intermediate hosts most species of mammals and birds, Including man. The infection in man is usually asymptomatic, but can become a severe and lethal illness in some special groups like the fetus of primoinfected pregnant woman, or in AIDS and transplanted patients. The transmission is due to ingestion of food or water contaminated with oocysts from cat feces as well as raw or rare cooked cyst containing meet. There is no available vaccine against toxoplasmosis, with some reports of the use ionizing radiation in order to attenuate or suppress the parasite. These studies are promising, but more research is needed to optimize the radiation process and to clarify those alterations caused on T gondii.Using a increasing doses of 60 Co irradiation on T.gondii tachyzoites, we studied many parameters such as morphology, both at optical and electron microscopy level, detection of DNA fragmentation, metabolism alterations (cellular oxidative burst, protein, nucleic acids and DNA synthesis), determination of the parasite survival both in in vivo and in vitro models, antigenicity and immunogenicity after the process, cellular invasion and irradiated tachyzoite induced protection. After definition of 200 Gy of 60 Co irradiation as the lower radiation dose that suppress parasite growth in vitro and in vivo, we found no detectable changes in parasite viability, its cell invasion capacity or in its structural proteins. DNA fragmentation like apoptosis or alterations of the parasite metabolism were similarly not affected by radiation. Mice infection with irradiated parasites induce partial protection when these animals were re-inoculated with non irradiated virulent parasites, inducing greater specific IgG levels as well as a longer survival. Irradiated T.gondii maintains its the ability of invasion, even under radiation effects. Based on our results we conclude that

  15. Dual role for inflammasome sensors NLRP1 and NLRP3 in murine resistance to Toxoplasma gondii.

    Science.gov (United States)

    Gorfu, Gezahegn; Cirelli, Kimberly M; Melo, Mariane B; Mayer-Barber, Katrin; Crown, Devorah; Koller, Beverly H; Masters, Seth; Sher, Alan; Leppla, Stephen H; Moayeri, Mahtab; Saeij, Jeroen P J; Grigg, Michael E

    2014-02-18

    Induction of immunity that limits Toxoplasma gondii infection in mice is critically dependent on the activation of the innate immune response. In this study, we investigated the role of cytoplasmic nucleotide-binding domain and leucine-rich repeat containing a pyrin domain (NLRP) inflammasome sensors during acute toxoplasmosis in mice. We show that in vitro Toxoplasma infection of murine bone marrow-derived macrophages activates the NLRP3 inflammasome, resulting in the rapid production and cleavage of interleukin-1β (IL-1β), with no measurable cleavage of IL-18 and no pyroptosis. Paradoxically, Toxoplasma-infected mice produced large quantities of IL-18 but had no measurable IL-1β in their serum. Infection of mice deficient in NLRP3, caspase-1/11, IL-1R, or the inflammasome adaptor protein ASC led to decreased levels of circulating IL-18, increased parasite replication, and death. Interestingly, mice deficient in NLRP1 also displayed increased parasite loads and acute mortality. Using mice deficient in IL-18 and IL-18R, we show that this cytokine plays an important role in limiting parasite replication to promote murine survival. Our findings reveal T. gondii as a novel activator of the NLRP1 and NLRP3 inflammasomes in vivo and establish a role for these sensors in host resistance to toxoplasmosis. Inflammasomes are multiprotein complexes that are a major component of the innate immune system. They contain "sensor" proteins that are responsible for detecting various microbial and environmental danger signals and function by activating caspase-1, an enzyme that mediates cleavage and release of the proinflammatory cytokines interleukin-1β (IL-1β) and IL-18. Toxoplasma gondii is a highly successful protozoan parasite capable of infecting a wide range of host species that have variable levels of resistance. We report here that T. gondii is a novel activator of the NLRP1 and NLRP3 inflammasomes in vivo and establish a role for these sensors in host resistance to

  16. In Vitro Infection of Human Nervous Cells by Two Strains of Toxoplasma gondii: A Kinetic Analysis of Immune Mediators and Parasite Multiplication

    Science.gov (United States)

    Mammari, Nour; Vignoles, Philippe; Halabi, Mohamad Adnan; Darde, Marie Laure; Courtioux, Bertrand

    2014-01-01

    The severity of toxoplasmic infection depends mainly on the immune status of the host, but also on the Toxoplasma gondii strains, which differ by their virulence profile. The relationship between the human host and T. gondii has not yet been elucidated because few studies have been conducted on human models. The immune mechanisms involved in the persistence of T. gondii in the brains of immunocompetent subjects and during the reactivation of latent infections are still unclear. In this study, we analyzed the kinetics of immune mediators in human nervous cells in vitro, infected with two strains of T. gondii. Human neuroblast cell line (SH SY5Y), microglial (CMH5) and endothelial cells (Hbmec) were infected separately by RH (type I) or PRU (type II) strains for 8 h, 14 h, 24 h and 48 h (ratio 1 cell: 2 tachyzoites). Pro-inflammatory protein expression was different between the two strains and among different human nervous cells. The cytokines IL-6, IL-8 and the chemokines MCP-1 and GROα, and SERPIN E1 were significantly increased in CMH5 and SH SY5Y at 24 h pi. At this point of infection, the parasite burden declined in microglial cells and neurons, but remained high in endothelial cells. This differential effect on the early parasite multiplication may be correlated with a higher production of immune mediators by neurons and microglial cells compared to endothelial cells. Regarding strain differences, PRU strain, but not RH strain, stimulates all cells to produce pro-inflammatory growth factors, G-CSF and GM-CSF. These proteins could increase the inflammatory effect of this type II strain. These results suggest that the different protein expression profiles depend on the parasitic strain and on the human nervous cell type, and that this could be at the origin of diverse brain lesions caused by T. gondii. PMID:24886982

  17. Meat juice serology for Toxoplasma gondii infection in chickens

    Directory of Open Access Journals (Sweden)

    Alice Vismarra

    2016-01-01

    Full Text Available Toxoplasma gondii is an important foodborne zoonosis. Free-range chickens are at particularly high risk of infection and are also excellent indicators of soil contamination by oocysts. In the present study, hearts of 77 freerange chickens were collected at slaughter. T. gondii meat juice enzyme-linked immunosorbent assay was performed with a commercial kit, following validation with positive controls, from experimentally infected chickens, and negative ones. Out of 77 samples, only 66 gave sufficient meat juice for serology. Of these, 24 (36.4% were positive for T. gondii considering the 5*standard deviation values (calculated on the optical density of negative controls, while all the samples were negative considering sample/positive% values. Parasite-specific polymerase chain reaction was carried out on all samples obtained from heart tissue and none were positive for the presence of T. gondii DNA. Results would suggest that further study on the use of meat juice with a validated serological test to detect T. gondii in chickens could lead to widespread epidemiological studies in this important intermediate host. However, sample collection and test specificity require further evaluation.

  18. Prevalence of encysted Toxoplasma gondii in raptors from Alabama.

    Science.gov (United States)

    Lindsay, D S; Smith, P C; Hoerr, F J; Blagburn, B L

    1993-12-01

    Little is known about the prevalence of encysted Toxoplasma gondii in wild birds. We examined the hearts and breast muscles from 101 raptors for encysted T. gondii. All of the raptors had been submitted for necropsy to the State Veterinary Diagnostic Laboratory, Auburn, Alabama. Tissues were digested in acid-pepsin solution and inoculated into groups of 3-5 laboratory mice. Toxoplasma gondii was isolated from 27 of 101 (26.7%) raptors: 8 of 12 (66.7%) red-shouldered hawks (Buteo lineatus), 13 of 27 (41.1%) red-tailed hawks (Buteo jamaicensis), 1 of 4 (25%) Cooper's hawks (Accipiter cooperi), 1 of 5 (20%) great horned owls (Bubo virginianus), 4 of 15 (26.7%) barred owls (Strix varia), and 1 of 3 (33.3%) kestrels (Falco sparverius). Toxoplasma gondii was not isolated from 3 broad-winged hawks (Buteo platypterus), 3 sharp-shinned hawks (Accipiter striatus), 6 barn owls (Tyto alba), 9 screech owls (Asio otus), a Mississippi kite (Ictinia misisippiensis), 2 golden eagles (Aquila chrysaetos), a bald eagle (Haliaeetus leucocephalus), 4 ospreys (Pandion haliaetus), 4 turkey vultures (Cathartes aura), or 2 black vultures (Coragyps atratus). No significant difference (P > 0.05) in prevalence was detected based on sex using chi-square analysis. Chi-square analysis of the data demonstrated that adult raptors had encysted stages of T. gondii significantly (P < 0.05) more often than did immature raptors.

  19. Detection of antibodies to the 97 kDa component of Toxoplasma gondii in samples of human serum

    Directory of Open Access Journals (Sweden)

    Ribeiro Alessandra Carla de Almeida

    2002-01-01

    Full Text Available This study was carried out to investigate the immune response against 97 kDa (p97 molecular marker of Toxoplasma gondii that has been characterized as a cytosolic protein and a component of the excreted-secreted antigens from this parasite. A total of 60 serum samples from patients were analyzed by enzime-linked immunosorbent assay and Western blot for toxoplasmosis. These samples were organized in three groups, based on clinical symptoms and results of serological tests. Group I: 20 samples reactive to IgG and IgM (acute phase; group II: 20 non-reactive samples (control group; and group III: 20 samples reactive only to IgG (chronic phase. Western blot was performed with total antigenic extracts or with excreted and secreted antigen from T. gondii to identify the fraction correspondent to p97. It was observed that this cytosolic component from T. gondii stimulates the immunologic system to produce both IgM and IgG antibodies in the beginning of the acute infection and IgG throughout the chronic stage of the asymptomatic toxoplasmosis.

  20. Association between Toxoplasma gondii seropositivity and memory function in nondemented older adults.

    Science.gov (United States)

    Wyman, Cynthia P; Gale, Shawn D; Hedges-Muncy, Ariana; Erickson, Lance D; Wilson, Eric; Hedges, Dawson W

    2017-05-01

    Toxoplasma gondii (T. gondii) seropositivity may be associated with decreased memory in older adults. To further investigate the association between T. gondii seropositivity and memory in nondemented older adults, we obtained serum samples from 114 nondemented older adults evaluated by the Alzheimer's Disease and Research Center at Washington University in St. Louis, Missouri, USA. We determined T. gondii seropositivity and anti-T. gondii IgG antibody titer and examined associations with memory function while controlling for socioeconomic status, education level, age, and apolipoprotein E4 status. There were few associations between T. gondii seropositivity or anti-T. gondii IgG antibodies and memory, although there was some support suggesting an interaction between anti-T. gondii and sex. In the seropositive-only sample, there was an inverse relationship between anti-T. gondii titer and performance on the selective reminding test. Overall, we found little evidence of an association between impaired memory function and T. gondii seropositivity and anti-T. gondii IgG antibodies in this sample of nondemented older adults. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Toxoplasma gondii in the Cornigliese sheep breed in Italy: Meat juice serology, in vitro isolation and genotyping.

    Science.gov (United States)

    Vismarra, A; Barilli, E; Miceli, M; Mangia, C; Genchi, M; Brindani, F; Kramer, L; Bacci, C

    2017-08-30

    Toxoplasma gondii is considered one of the most important food-borne parasitic zoonoses globally and sheep are important intermediate hosts of the parasite. Meat and milk from infected sheep are considered an important source of infection for humans. Here, the authors evaluated T. gondii infection in the Italian Cornigliese sheep breed using meat juice ELISA, and in vitro assay for followed by Real Time-PCR and PCR-RFLP. Twenty-one hearts were collected at slaughter. Meat juice serology was carried out on all samples, while eleven hearts with the highest antibody titres were subjected to acid-peptic digestion and seeding onto Vero cells. DNA was extracted at three different time points following seeding. PCR-positive samples were then genotyped by PCR-RFLP. All the meat juice samples were positive for IgG antibodies against p30 protein of T. gondii. Five of the 11 samples, seeded onto Vero cells, were positive in PCR made on DNA extracted after 21days of culture and the PCR-RFLP revealed a Type-II or Type II variant profile at 9/10 loci. Two out of five samples showed an increase in terms of parasite growth by comparing the Cq values at three different time points. To the authors' knowledge, this is the first report of in vitro cultivation of T. gondii from muscle tissue of naturally-infected sheep. In vitro assays may be a promising alternative to bioassays and further studies are necessary in order to improve assay performance and to identify possible early markers of parasite proliferation. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. In silico and in vivo analysis of Toxoplasma gondii epitopes by correlating survival data with peptide-MHC-I binding affinities.

    Science.gov (United States)

    Huang, Si-Yang; Jensen, Maria Risager; Rosenberg, Carina Agerbo; Zhu, Xing-Quan; Petersen, Eskild; Vorup-Jensen, Thomas

    2016-07-01

    Protein antigens comprising peptide motifs with high binding affinity to major histocompatibility complex class I (MHC-I) molecules are expected to induce a stronger cytotoxic T-lymphocyte response and thus provide better protection against infection with microorganisms where cytotoxic T-cells are the main effector arm of the immune system. Data on cyst formation and survival were extracted from past studies on the DNA immunization of mice with plasmids coding for Toxoplasma gondii antigens. From in silico analyses of the vaccine antigens, the correlation was tested between the predicted affinity for MHC-I molecules of the vaccine peptides and the survival of immunized mice after challenge with T. gondii. ELISPOT analysis was used for the experimental testing of peptide immunogenicity. Predictions for the Db MHC-I molecule produced a strong, negative correlation between survival and the dissociation constant of vaccine-derived peptides. The in silico analyses of nine T. gondii antigens identified peptides with a predicted dissociation constant in the interval from 10nM to 40μM. ELISPOT assays with splenocytes from T. gondii-infected mice further supported the importance of the peptide affinity for MHC-I. In silico analysis clearly helped the search for protective vaccine antigens. The ELISPOT analysis confirmed that the predicted T-cell epitopes were immunogenic by their ability to release interferon gamma in spleen cells. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  3. Detection of Toxolasma gondii in captive wild felids.

    Science.gov (United States)

    Buddhirongawatr, Ruangrat; Tungsudjai, Siriporn; Chaichoune, Kridsada; Sangloung, Charoonluk; Tantawiwattananon, Nitipan; Phonaknguen, Rassameepen; Sukthana, Yaowalark

    2006-01-01

    Toxoplasma gondii can infect all species of warm-blooded animals, including humans, and causes serious diseases in immunocompromized hosts. Live tachyzoites derived from serial passage in HeLa culture were used in the Sabin-Feldman dye test for detection of Toxoplasma gondii antibody in serum samples of 21 captive wild felids including one fishing cat (Prion nailurus viverrina), one leopard (Panthera pardus), two flat-headed cats (Prion nailurus planiceps), 6 tigers (Panthera tigris), two leopard cats (Felis bengalensis), two clouded leopards (Felis nebulosa), 3 pumas (Puma concolor), and 4 jungle cats (Felis chaus). Antibodies to Toxoplasma gondii were founded in 9 of 21 felids (42.8%). This study revealed that cell culture-derived tachyzoites can be used successfully as a source of live organisms in a gold standard Sabin-Feldman dye test, which is simpler, cheaper and less ethically sensitive than in vivo inoculation.

  4. Encephalomyelitis by Toxoplasma gondii in a captive fossa (Cryptoprocta ferox).

    Science.gov (United States)

    Corpa, J M; García-Quirós, A; Casares, M; Gerique, A C; Carbonell, M D; Gómez-Muñoz, M T; Uzal, F A; Ortega, J

    2013-03-31

    Encephalomyelitis due to Toxoplasma gondii was diagnosed in a fossa (Cryptoprocta ferox). The animal had ataxia, atrophy of hind limb muscles and progressive wasting before dying 12 months after the onset of clinical signs. Toxoplasmosis was suspected antemortem based on clinical signs and the detection of T. gondii DNA by PCR on EDTA-blood from live animal. Necropsy revealed necrotizing gastritis and severe emaciation. The main histological lesions included non-suppurative encephalomyelitis, with dilation of myelin sheaths and swollen axons in the spinal cord, and multifocal gliosis in the brain with intralesional protozoan cysts that stained positive for T. gondii immunohistochemistry. To the authors' knowledge, this is the first report of toxoplasmosis in a fossa, and a new host record. Copyright © 2012 Elsevier B.V. All rights reserved.

  5. Seroprevalence of Toxoplasma gondii in domestic sheep in Belgium.

    Science.gov (United States)

    Verhelst, D; De Craeye, S; Vanrobaeys, M; Czaplicki, G; Dorny, P; Cox, E

    2014-09-15

    Even though infected sheep are a potential source of Toxoplasma gondii infection in humans, information is lacking concerning the seroprevalence of T. gondii infection in sheep in Belgium. We examined 3170 serum samples for anti-Toxoplasma IgG in sheep by total lysate antigen (TLA) enzyme-linked immunosorbent assay (ELISA). IgG to T. gondii was demonstrated in 87.4% of the tested sheep and in 96.2% of the 209 tested flocks. The seroprevalences in Antwerp (65.2%) and Wallonia (68.6%) are statistically lower than in the other regions in Belgium (96.7-97.8%) (Psheep in Belgium and confirms the high prevalence of Toxoplasma-specific IgG antibodies in the sheep population. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Toxoplasma gondii in women with recent abortion from Southern Mexico

    Directory of Open Access Journals (Sweden)

    Ivonne Beatriz Hernández-Cortazar

    2016-03-01

    Full Text Available Objective: To estimate the presence, parasite burden, percentage of avidity and risk factors to seropositivity for Toxoplasma gondii (T. gondii in women with recent abortion attended at the two main hospitals from Merida, Yucatan, Mexico. Methods: Seroprevalence and IgG avidity were estimated from 161 blood samples from aborting women and risk factors associated with serological status were determined. Only 130 from 161 samples were analyzed by quantitative PCR (qPCR and a nested-PCR (nPCR to detect T. gondii-DNA. Results: Seroprevalence of Toxoplasma IgM and IgG was 3.72% (6/161 and 59.00% (95/161, respectively; 98.94% (94/95 of the women showed high-avidity index and only 1.05% (1/95 demonstrated low-avidity. For qPCR, 3.84% (5/130 of the samples were detected with T. gondii-DNA and all positive samples showed a low parasite load (< 1 parasite/mL. For nPCR, 6.92% (9/130 of positivity was found. Logistic regression analysis showed a positive association between IgG-seropositivity and potable-drinking-water intake in households (P < 0.020, odds ratio = 11.62, 95% confidence interval = 0.011–0.683. Conclusions: In this study, the detection of T. gondii-DNA in IgG-positive women suggests in some cases active parasitemia, even when they demonstrated high-avidity index. Reinfection cases could be presented due to the high circulation of the parasite in the study region. T. gondii could play an important role as cause of abortion and municipal potable-water could be an important risk factor of infection.

  7. Toxoplasma gondii decreases the reproductive fitness in mice.

    Directory of Open Access Journals (Sweden)

    Katerina Dvorakova-Hortova

    Full Text Available Toxoplasma gondii is a common protozoan parasite that infects warm-blooded animals throughout the world, including mice and humans. During infection, both, the parasite and the host, utilize various mechanisms to maximize their own reproductive success. Mice and humans are both the intermediate hosts for Toxoplasma gondii, which forms specialized vacuoles containing reproductive cysts in the formers' tissue. As half of the human population is infected, developing a disease called toxoplasmosis, along with an ever-growing number of couples suffering with idiopathic infertility, it is therefore surprising that there is a lack of research on how Toxoplasma gondii can alter reproductive parameters. In this study, a detailed histometric screening of the testicular function along with the levels of the pituitary luteinizing hormone (LH were analysed in infected mice. Data on relative testis and epididymis weight, and sperm count were also collected. Based on the results obtained, the level of LH in the urine of Toxoplasma gondii infected mice was lower compared to the control. In direct correlation with the hormone level, testicular function and sperm production was also significantly lower in Toxoplasma gondii positive group using sperm count and histometric analysis as a marker. Not only were the number of leptotene primary spermatocytes and spermatids lowered, but the number of Sertoli cells and the tubule diameter were elevated. In parallel, a pilot epigenetic study on global testicular methylation, and specific methylation of Crem, Creb1 and Hspa1genes essential for successfully ongoing spermatogenesis was performed. Global methylation was elevated in Toxoplasma infected mice, and differences in the DNA methylation of selected genes were detected between the Toxoplasma positive and control group. These findings demonstrate a direct relation between Toxoplasma gondii infection and the decrease of male reproductive fitness in mice, which may

  8. Dual Role for Inflammasome Sensors NLRP1 and NLRP3 in Murine Resistance to Toxoplasma gondii

    Science.gov (United States)

    Gorfu, Gezahegn; Cirelli, Kimberly M.; Melo, Mariane B.; Mayer-Barber, Katrin; Crown, Devorah; Koller, Beverly H.; Masters, Seth; Sher, Alan; Leppla, Stephen H.; Moayeri, Mahtab; Saeij, Jeroen P. J.; Grigg, Michael E.

    2014-01-01

    ABSTRACT Induction of immunity that limits Toxoplasma gondii infection in mice is critically dependent on the activation of the innate immune response. In this study, we investigated the role of cytoplasmic nucleotide-binding domain and leucine-rich repeat containing a pyrin domain (NLRP) inflammasome sensors during acute toxoplasmosis in mice. We show that in vitro Toxoplasma infection of murine bone marrow-derived macrophages activates the NLRP3 inflammasome, resulting in the rapid production and cleavage of interleukin-1β (IL-1β), with no measurable cleavage of IL-18 and no pyroptosis. Paradoxically, Toxoplasma-infected mice produced large quantities of IL-18 but had no measurable IL-1β in their serum. Infection of mice deficient in NLRP3, caspase-1/11, IL-1R, or the inflammasome adaptor protein ASC led to decreased levels of circulating IL-18, increased parasite replication, and death. Interestingly, mice deficient in NLRP1 also displayed increased parasite loads and acute mortality. Using mice deficient in IL-18 and IL-18R, we show that this cytokine plays an important role in limiting parasite replication to promote murine survival. Our findings reveal T. gondii as a novel activator of the NLRP1 and NLRP3 inflammasomes in vivo and establish a role for these sensors in host resistance to toxoplasmosis. PMID:24549849

  9. Organizational changes of the daughter basal complex during the parasite replication of Toxoplasma gondii.

    Directory of Open Access Journals (Sweden)

    Ke Hu

    2008-01-01

    Full Text Available The apicomplexans are a large group of parasitic protozoa, many of which are important human and animal pathogens, including Plasmodium falciparum and Toxoplasma gondii. These parasites cause disease only when they replicate, and their replication is critically dependent on the proper assembly of the parasite cytoskeletons during cell division. In addition to their importance in pathogenesis, the apicomplexan parasite cytoskeletons are spectacular structures. Therefore, understanding the cytoskeletal biogenesis of these parasites is important not only for parasitology but also of general interest to broader cell biology. Previously, we found that the basal end of T. gondii contains a novel cytoskeletal assembly, the basal complex, a cytoskeletal compartment constructed in concert with the daughter cortical cytoskeleton during cell division. This study focuses on key events during the biogenesis of the basal complex using high resolution light microscopy, and reveals that daughter basal complexes are established around the duplicated centrioles independently of the structural integrity of the daughter cortical cytoskeleton, and that they are dynamic "caps" at the growing ends of the daughters. Compartmentation and polarization of the basal complex is first revealed at a late stage of cell division upon the recruitment of an EF-hand containing calcium binding protein, TgCentrin2. This correlates with the constriction of the basal complex, a process that can be artificially induced by increasing cellular calcium concentration. The basal complex is therefore likely to be a new kind of centrin-based contractile apparatus.

  10. Titres of Specific Antibodies against Toxoplasma gondii in Goats and their Kids

    Directory of Open Access Journals (Sweden)

    Ľubica Mišurová

    2009-01-01

    Full Text Available The aim of our study was to perform repeated determination of specific antibody levels in mothers and their kids in order to assess indirectly the possibility of vertical transmission of toxoplasmosis in goats. Twenty-eight goats with their kids were included in the study. The following variables were assessed: number of born kids in relation to antibody titres of goats; levels of specific antibodies in the blood of goats and kids; and concentrations of immunoglobulins (Ig, total protein (TP and total globulins (G in order to define the end of colostral immunity and the start of active production of antibodies in kids under 69 days of age. Specific antibodies against Toxoplasma gondii in goats were detected by IFAT in titres ranging from 0 to 1 280. Out of a total of 28 animals, 5 goats were negative (17.9% and 23 goats were seropositive (82.1%. The goats delivered 42 kids. A total ratio of number of kids to number of mothers was 1.5. Partial evaluation of results in goats without positive titre against T. gondii before parturition and goats with positive titre showed that negative goats tended to have more kids (p p < 0.01 of monitored non-specific immunity indicators. During this period, we observed increased titres of specific antibodies against toxoplasmosis in 20 kids (5 kids 41 days old, 5 kids 55 days old, and 10 kids 69 days old and thus we could assume the possibility of vertical transmission of toxoplasmosis.

  11. Recombinant TgHSP70 Immunization Protects against Toxoplasma gondii Brain Cyst Formation by Enhancing Inducible Nitric Oxide Expression

    Directory of Open Access Journals (Sweden)

    Neide M. Silva

    2017-04-01

    Full Text Available Toxoplasma gondii is known to cause congenital infection in humans and animals and severe disease in immunocompromised individuals; consequently development of vaccines against the parasite is highly necessary. Under stress conditions, T. gondii expresses the highly immunogenic heat shock protein 70 (TgHSP70. Here, we assessed the protective efficacy of rTgHSP70 immunization combined with Alum in oral ME-49 T. gondii infection and the mechanisms involved on it. It was observed that immunized mice with rTgHSP70 or rTgHSP70 adsorbed in Alum presented a significantly reduced number of cysts in the brain that was associated with increased iNOS+ cell numbers in the organ, irrespective the use of the adjuvant. Indeed, ex vivo experiments showed that peritoneal macrophages pre-stimulated with rTgHSP70 presented increased NO production and enhanced parasite killing, and the protein was able to directly stimulate B cells toward antibody producing profile. In addition, rTgHSP70 immunization leads to high specific antibody titters systemically and a mixed IgG1/IgG2a response, with predominance of IgG1 production. Nonetheless, it was observed that the pretreatment of the parasite with rTgHSP70 immune sera was not able to control T. gondii internalization and replication by NIH fibroblast neither peritoneal murine macrophages, nor anti-rTgHSP70 antibodies were able to kill T. gondii by complement-mediated lysis, suggesting that these mechanisms are not crucial to resistance. Interestingly, when in combination with Alum, rTgHSP70 immunization was able to reduce inflammation in the brain of infected mice and in parallel anti-rTgHSP70 immune complexes in the serum. In conclusion, immunization with rTgHSP70 induces massive amounts of iNOS expression and reduced brain parasitism, suggesting that iNOS expression and consequently NO production in the brain is a protective mechanism induced by TgHSP70 immunization, therefore rTgHSP70 can be a good candidate for

  12. Toxoplasma gondii infection in Bactrian camel (Camelus bactrianus) in China.

    Science.gov (United States)

    Wang, M; Wang, Y H; Meng, P; Ye, Q; Zhang, D L

    2013-02-18

    Camel is important to the economy of many countries. We report Toxoplasma gondii infection in Bactrian camels (Camelus bactrianus), first for this host. Antibodies to T. gondii were found in sera of 7 of 234 C. bactrianus from Qinghai Province, northwestern China. Sera were tested by a commercial indirect hemagglutination test at a cut-off of 1:64. Age or the gender of the camel did not significantly affect the seroprevalence. Results are of public health and economic importance because camel milk and meat are used for human consumption in many countries, including China. Copyright © 2012 Elsevier B.V. All rights reserved.

  13. Toxoplasma gondii and subversion of the immune system.

    Science.gov (United States)

    Buzoni-Gatel, Dominique; Werts, Catherine

    2006-10-01

    Toxoplasma gondii is an intracellular obligate parasite that enters the host via the gastrointestinal tract. The parasite is able to evade or subvert the immune response of its host via various mechanisms. Here, we discuss a recent in vitro study by Eric Denkers and colleagues that focused on the modulation of gene transcription of host macrophages stimulated by lipopolysaccharide (LPS) following infection with T. gondii. The parasite was able to block the response of macrophages to LPS, a major immunostimulatory component of Gram negative bacteria, thus possibly avoiding the hyperinflammatory response of the host to gut microflora, among which Gram negative bacteria are abundant.

  14. 21 CFR 866.3780 - Toxoplasma gondii serological reagents.

    Science.gov (United States)

    2010-04-01

    ... Section 866.3780 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... consist of antigens and antisera used in serological tests to identify antibodies to Toxoplasma gondii in serum. Additionally, some of these reagents consist of antisera conjugated with a fluorescent dye...

  15. Seroprevalence and risk factors of Toxoplasma gondii infection ...

    African Journals Online (AJOL)

    The infection is also associated with human immune deficiency virus/acquired immunodeficiency syndrome (HIV/AIDS). In Rwanda, the burden and risk factors of T. gondii infection among pregnant women and among HIV infected pregnant women is largely unknown. This cross-sectional study aimed at determining the ...

  16. The neurotropic parasite Toxoplasma gondii increases dopamine metabolism

    Science.gov (United States)

    The common parasite Toxoplasma gondii induces behavioral alterations in its hosts including phenotypes increasing the likelihood of its transmission in rodents and reports of psychobehavioral alterations in humans. We have found that elevated levels of dopamine are associated with the encysted stage...

  17. Seroprevalence and risk factors of Toxoplasma gondii infection ...

    African Journals Online (AJOL)

    Leonard Mboera

    Abstract. Background: Toxoplasma gondii infection in pregnancy, if left untreated, is associated with spontaneous abortions, low birth weight babies, congenital deformities and intrauterine deaths. The infection is also associated with human immune deficiency virus/acquired immunodeficiency syndrome (HIV/AIDS). In.

  18. Anti- toxoplasma gondii activity of constituents from Balsamocitrus ...

    African Journals Online (AJOL)

    Isolation, characterization and anti-Toxoplasma gondii activity of constituents from the CH2Cl2/MeOH (1/1) extract of the roots of the cameroonian plant Balsamocitrus camerunensis L. were investigated in this study. Four known coumarins derivatives were isolated, namely, marmin (1), imperatorin (2), xanthoxyletin (3), ...

  19. Sero-prevalence of Toxoplasma gondii in Danish pigs

    DEFF Research Database (Denmark)

    Kofoed, Kristina Grønbech; Vorslund-Kiær, Mia; Nielsen, Henrik Vedel

    2017-01-01

    In 2015, the World Health Organisation rated toxoplasmosis as one of the most important food borne zoonotic diseases in the world. In addition, recent studies have associated Toxoplasma gondii sero-positivity with severe mental illnesses such as schizophrenia. Intake of raw or insufficiently cooked...

  20. Antibodies to Toxoplasma gondii in Backyard and Roaming Pigs ...

    African Journals Online (AJOL)

    Toxoplasma gondii, the etiologic agent of Toxoplasmosis, can be transmitted to pigs through the ingestion of oocysts, and to humans through consumption of pork containing viable cysts causing neonatal deaths and abortion in animals, and opportunistic infections in immunocompromised humans. The objective of this ...

  1. Toxoplasma gondii infections in sheep in Sicily, southern Italy

    DEFF Research Database (Denmark)

    Vesco, G; Buffolano, W; La Chiusa, S

    2007-01-01

    The aim of the study was to determine the burden of Toxoplasma gondii-infections in sheep in Sicily, southern Italy and the risk factors for infection. Sera from 1961 sheep were collected just before slaughtering from 62 farms located in 8 out of 9 Sicilian administrative districts. The sera were...

  2. Toxoplasma gondii: epidemiology, feline clinical aspects, and prevention

    Science.gov (United States)

    Toxoplasma gondii is a parasite of birds and mammals. Cats are the only definitive host and thus the only source of infective oocysts, but other mammals and birds can develop tissue cysts. While feline infections are typically asymptomatic, infection during human pregnancy can cause severe disease i...

  3. Toxoplasma gondii decreases the reproductive fitness in mice

    Czech Academy of Sciences Publication Activity Database

    Dvořáková-Hortová, K.; Šídlová, A.; Děd, Lukáš; Hladovcová, D.; Vieweg, M.; Weidner, W.; Steger, K.; Stopka, P.; Paradowska-Dogan, A.

    2014-01-01

    Roč. 9, č. 6 (2014), s. 1-11 E-ISSN 1932-6203 R&D Projects: GA MŠk(CZ) ED1.1.00/02.0109 Institutional support: RVO:86652036 Keywords : Toxoplasma gondii * reproductive fitness * DNA methylation Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.234, year: 2014

  4. Detection of Toxoplasma gondii with a DNA molecular beacon probe

    Science.gov (United States)

    Zhou, Cun; Xu, Shichao; Yang, Juan; Zhang, Jimei; Dai, Zhao; Zheng, Guo; Sun, Bo; Sun, Shuqing; Feng, Teilin; Zi, Yan; Liang, Chu; Luo, Hao

    2009-07-01

    Toxoplasma gondii is a kind of microscopic parasite that may infect humans, and there are increasing concerns on the early detection of latent Toxoplasma gondii infection in recent years. This research highlights a new type of molecular beacon (MB) fluorescent probe for Toxoplasma DNA testing. We combined high-efficiency fluorescent inorganic core-shell quantum dots-CdTe/ZnS (as fluorescent energy donor) and BHQ-2 (energy acceptor) to the single-strand DNA of Toxoplasma gondii, and a molecular beacon sensing system based on fluorescence resonance energy transfer (FRET) was achieved. Core-shell quantum dots CdTe/ZnS was firstly prepared in aqueous solution, and the influencing factor of its fluorescent properties, including CdTe/Na2S/Zn(CH3COO)2 (v/v), dependence of reaction time, temperature, and pH, is investigated systematically. The synthesized quantum dots and molecular beacon were characterized by transmission electron microscopy (TEM), ultraviolet-visible spectrophotometer (UV-vis), fluorescent spectrophotometer (FS), respectively. The TEM results showed that CdTe/ZnS core-shell quantum dots is ~11nm in size, and the quantum dots is water-soluble well. The sensing ability of target DNA of assembled MB was investigated, and results showed that the target Toxoplasma gonddi DNA can be successfully detected by measuring the change of fluorescence intensity. The results showed that the current sensing probe will be a useful and convenient tool in Toxoplasma gondii early detection.

  5. Genetic approaches to defining pathogenesis of Toxoplasma gondii

    Science.gov (United States)

    Toxoplasma gondii is a widespread parasite of warm-blooded vertebrates that also causes opportunistic infections in humans. Rodents are a natural host for transmission to cats, which serve as the definitive host for sexual development. The laboratory mouse provides a model to study pathogenesis. Str...

  6. SPORULATION AND SURVIVAL OF TOXOPLASMA GONDII OOCYSTS IN SEA WATER

    Science.gov (United States)

    Since 1992, we have been collaborating in studies on southern sea otters (Enhdyra lutris nereis) as part of a program to define factors which may be responsible for limiting the growth of the southern sea otter population. We previously demonstrated Toxoplasma gondii in sea otter...

  7. Seroprevalence of Toxoplasma gondii in seabirds from Abrolhos Archipelago, Brazil

    Science.gov (United States)

    Toxoplasma gondii is a coccidian parasite that infects almost all warm-blooded animals, including birds. Abrolhos is an archipelago of five islands, located in the Atlantic Ocean, 56 nautical kilometers from the south coast of the state of Bahia, northeastern Brazil. Part of this archipelago is a Na...

  8. Phylogeography of Toxoplasma gondii points to a South American origin

    Science.gov (United States)

    Toxoplasma gondii, a protozoan found ubiquitously in mammals and birds, is the etiologic agent of toxoplasmosis, a disease causing substantial Public Health burden worldwide, including about 200,000 new cases of congenital toxoplasmosis each year. Clinical severity has been shown to vary across geog...

  9. The structure of bradyzoite-specific enolase from Toxoplasma gondii reveals insights into its dual cytoplasmic and nuclear functions

    Energy Technology Data Exchange (ETDEWEB)

    Ruan, Jiapeng [Northwestern University, 320 E. Superior Street, Morton 7-601, Chicago, IL 60611 (United States); Mouveaux, Thomas [Université Lille Nord de France, (France); Light, Samuel H.; Minasov, George; Anderson, Wayne F. [Northwestern University, 320 E. Superior Street, Morton 7-601, Chicago, IL 60611 (United States); Tomavo, Stanislas [Université Lille Nord de France, (France); Ngô, Huân M., E-mail: h-ngo@northwestern.edu [Northwestern University, 320 E. Superior Street, Morton 7-601, Chicago, IL 60611 (United States); BrainMicro LLC, 21 Pendleton Street, New Haven, CT 06511 (United States)

    2015-03-01

    The second crystal structure of a parasite protein preferentially enriched in the brain cyst of T. gondii has been solved at 2.75 Å resolution. Bradyzoite enolase 1 is reported to have differential functions as a glycolytic enzyme and a transcriptional regulator in bradyzoites. In addition to catalyzing a central step in glycolysis, enolase assumes a remarkably diverse set of secondary functions in different organisms, including transcription regulation as documented for the oncogene c-Myc promoter-binding protein 1. The apicomplexan parasite Toxoplasma gondii differentially expresses two nuclear-localized, plant-like enolases: enolase 1 (TgENO1) in the latent bradyzoite cyst stage and enolase 2 (TgENO2) in the rapidly replicative tachyzoite stage. A 2.75 Å resolution crystal structure of bradyzoite enolase 1, the second structure to be reported of a bradyzoite-specific protein in Toxoplasma, captures an open conformational state and reveals that distinctive plant-like insertions are located on surface loops. The enolase 1 structure reveals that a unique residue, Glu164, in catalytic loop 2 may account for the lower activity of this cyst-stage isozyme. Recombinant TgENO1 specifically binds to a TTTTCT DNA motif present in the cyst matrix antigen 1 (TgMAG1) gene promoter as demonstrated by gel retardation. Furthermore, direct physical interactions of both nuclear TgENO1 and TgENO2 with the TgMAG1 gene promoter are demonstrated in vivo using chromatin immunoprecipitation (ChIP) assays. Structural and biochemical studies reveal that T. gondii enolase functions are multifaceted, including the coordination of gene regulation in parasitic stage development. Enolase 1 provides a potential lead in the design of drugs against Toxoplasma brain cysts.

  10. Toxoplasma gondii abortion storm in sheep on a Texas farm and isolation of mouse virulent atypical genotype T. gondii from an aborted lamb from a chronically infected ewe

    Science.gov (United States)

    Sheep are commonly infected with the protozoan parasite, Toxoplasma gondii. Infection may cause early embryonic death and resorption, fetal death and mummification, abortion, stillbirth, and neonatal death. Most sheep acquire T. gondii infection after birth. Recent studies reported that repeat ovine...

  11. Phylogeography of Toxoplasma gondii points to a South American origin.

    Science.gov (United States)

    Bertranpetit, Emilie; Jombart, Thibaut; Paradis, Emmanuel; Pena, Hilda; Dubey, Jitender; Su, Chunlei; Mercier, Aurélien; Devillard, Sébastien; Ajzenberg, Daniel

    2017-03-01

    Toxoplasma gondii, a protozoan found ubiquitously in mammals and birds, is the etiologic agent of toxoplasmosis, a disease causing substantial public health burden worldwide, including about 200,000 new cases of congenital toxoplasmosis each year. Clinical severity has been shown to vary across geographical regions, with South America exhibiting the highest burden. Unfortunately, the drivers of these heterogeneities are still poorly understood, and the geographical origin and historical spread of the pathogen worldwide are currently uncertain. A worldwide sample of 168 T. gondii isolates gathered in 13 populations was sequenced for five fragments of genes (140 single nucleotide polymorphisms from 3153bp per isolate). Phylogeny based on Maximum likelihood methods with estimation of the time to the most recent common ancestor (TMRCA) and geostatistical analyses were performed for inferring the putative origin of T. gondii. We show that extant strains of the pathogen likely evolved from a South American ancestor, around 1.5 million years ago, and reconstruct the subsequent spread of the pathogen worldwide. This emergence is much more recent than the appearance of ancestral T. gondii, believed to have taken place about 11 My ago, and follows the arrival of felids in this part of the world. We posit that an ancestral lineage of T. gondii likely arrived in South America with felids and that the evolution of oral infectivity through carnivorism and the radiation of felids in this region enabled a new strain to outcompete the ancestral lineage and undergo a pandemic radiation. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. SEROLOGICAL SURVEY OF TOXOPLASMA GONDII IN DOGS AND CATS

    Directory of Open Access Journals (Sweden)

    Faiz Ahmad, Azhar Maqbool, Ashar Mahfooz and Sikandar Hayat

    2001-01-01

    Full Text Available A serological survey for Toxoplasma gondii in dogs (n=40 and cats (n= 10 was conducted by using a Latex agglutination test (LAT. The overall seroprevalence of T. gondii in canines was 50%. Out of total 9 dogs were found seropositive at 1:256, giving an evidence of presence of infection. The seroprevalence of T. gondii in canines was inversely related to the age i.e., 52% at 6 months and 33.33% at 4 years of age. Little variation in seropositivity was observed between males (57.89% and females (42.85% or between exotic (46.15% and local (57.14% breeds. However, tremendous variation in seropositivity was found between stray dogs (78.57% and pet dogs (34.61 % and between dogs having close contact with cats (50% and without contact {16.16%. Out of the tested bitches, 66.66% were seropositive, mostly at I: 16 indicating residual immunity. The overall seroprevalence of T. gondii in cats was 60%, three at screening dilution of 1:256, suggesting recent exposure to Toxoplasma. The seroprevalence of T. gondii in cats was directly related to age. A significant difference in seropositivity was observed between stray cats (66.66% and indoor cats (57.14% and between females (70% and males (40%.The seropositive rate in local breeds of cats was high (66.66% as compared with exotic (50%. This test might give false positive results due to interfering factors (rheumatoid factor and IgG class antibodies. So it is not a "Gold standard" test for the concrete diagnosis of toxoplasmosis.

  13. Seroprevalence of Toxoplasma gondii infection and risk factors in domestic sheep in Henan province, central China.

    Science.gov (United States)

    Zhang, Nian; Wang, Shuai; Wang, Dong; Li, Chaoying; Zhang, Zhenchao; Yao, Zhijun; Li, Tingting; Xie, Qing; Liu, Shiguo; Zhang, Haizhu

    2016-01-01

    Sheep are highly susceptible to infections with Toxoplasma gondii and play a major role in the transmission of toxoplasmosis to humans. In the present study, 779 serum samples from sheep were collected from Henan province, central China from March 2015 to May 2016, and antibodies to T. gondii were detected by modified agglutination test (MAT). The overall seroprevalence of T. gondii in sheep was 12.71% (99/779). The risk factors significantly associated with T. gondii seroprevalence were the geographical origin, age, presence of cats, and the rearing system. This is the first report of T. gondii infection in sheep in Henan province, central China, and of an association of seropositivity to T. gondii with risk factors. © N. Zhang et al., published by EDP Sciences, 2016.

  14. Seroepidemiology of Toxoplasma gondii infection in pregnant women in a public hospital in northern Mexico

    Directory of Open Access Journals (Sweden)

    Díaz-García Juan

    2006-07-01

    Full Text Available Abstract Background Toxoplasma gondii (T. gondii infection in pregnant women represents a risk for congenital disease. There is scarce information about the epidemiology of T. gondii infection in pregnant women in Mexico. Therefore, we sought to determine the prevalence of T. gondii infection and associated socio-demographic, clinical and behavioural characteristics in a population of pregnant women of Durango City, Mexico. Methods Three hundred and forty three women seeking prenatal care in a public hospital of Durango City in Mexico were examined for T. gondii infection. All women were tested for anti-T. gondii IgM and IgG antibodies by using IMx Toxo IgM and IMx Toxo IgG 2.0 kits (Abbott Laboratories, Abbott Park, IL, USA, respectively. Socio-demographic, clinical and behavioural characteristics from each participant were also obtained. Results Twenty one out of the 343 (6.1% women had IgG anti-T. gondii antibodies. None of the 343 women had IgM anti-T. gondii antibodies. Multivariate analysis using logic regression showed that T. gondii infection was associated with living in a house with soil floor (adjusted OR = 7.16; 95% CI: 1.39–36.84, residing outside of Durango State (adjusted OR = 4.25; 95% CI: 1.72–10.49, and turkey meat consumption (adjusted OR = 3.85; 95% CI: 1.30–11.44. Other characteristics as cat contact, gardening, and food preferences did not show any association with T. gondii infection. Conclusion The prevalence of T. gondii infection in pregnant women of Durango City is low as compared with those reported in other regions of Mexico and the majority of other countries. Poor housing conditions as soil floors, residing in other Mexican States, and turkey meat consumption might contribute to acquire T. gondii infection.

  15. ROP18 is a rhoptry kinase controlling the intracellular proliferation of Toxoplasma gondii.

    Directory of Open Access Journals (Sweden)

    Hiba El Hajj

    2007-02-01

    Full Text Available Toxoplasma gondii is an obligate intracellular parasite for which the discharge of apical organelles named rhoptries is a key event in host cell invasion. Among rhoptry proteins, ROP2, which is the prototype of a large protein family, is translocated in the parasitophorous vacuole membrane during invasion. The ROP2 family members are related to protein-kinases, but only some of them are predicted to be catalytically active, and none of the latter has been characterized so far. We show here that ROP18, a member of the ROP2 family, is located in the rhoptries and re-localises at the parasitophorous vacuole membrane during invasion. We demonstrate that a recombinant ROP18 catalytic domain (amino acids 243-539 possesses a protein-kinase activity and phosphorylate parasitic substrates, especially a 70-kDa protein of tachyzoites. Furthermore, we show that overexpression of ROP18 in transgenic parasites causes a dramatic increase in intra-vacuolar parasite multiplication rate, which is correlated with kinase activity. Therefore, we demonstrate, to our knowledge for the first time, that rhoptries can discharge active protein-kinases upon host cell invasion, which can exert a long-lasting effect on intracellular parasite development and virulence.

  16. Understanding mechanisms and the role of differentiation in pathogenesis of Toxoplasma gondii: a review

    Directory of Open Access Journals (Sweden)

    William J Sullivan Jr

    2009-03-01

    Full Text Available Parasite differentiation from proliferating tachyzoites into latent bradyzoites is central to pathogenesis and transmission of the intracellular protozoan pathogen Toxoplasma gondii. The presence of bradyzoite-containing cysts in human hosts and their subsequent rupture can cause life-threatening recrudescence of acute infection in the immunocompromised and cyst formation in other animals contributes to zoonotic transmission and widespread dissemination of the parasite. In this review, we discuss the evidence showing how the clinically relevant process of bradyzoite differentiation is regulated at both transcriptional and post-transcriptional levels. Specific regulatory factors implicated in modulating bradyzoite differentiation include promoter-based cis-elements, epigenetic modifications and protein translation control through eukaryotic initiation factor -2 (eIF2. In addition to a summary of the current state of knowledge in these areas we discuss the pharmacological ramifications and pose some questions for future research.

  17. Seropositivity of Toxoplasma gondii in domestic donkeys (Equus asinus) and isolation of T. gondii from farm cats.

    Science.gov (United States)

    Dubey, J P; Ness, S L; Kwok, O C H; Choudhary, S; Mittel, L D; Divers, T J

    2014-01-17

    Donkeys (Equus asinus) are used as both companion and working animals throughout the world and in some countries, their meat and milk are used for human consumption. Here we report the first serological survey of Toxoplasma gondii in donkeys in the United States. Serum samples from 373 donkeys from eight farms in five states were tested for T. gondii antibodies by the modified agglutination test (MAT). Twenty-four of 373 (6.4%) of donkeys were seropositive, with MAT titers ranging from 25 to ≥ 200. All seropositive donkeys were Miniature breed. Seropositivity prevalence was 7.0% in female donkeys (20/282) and 4.1% in male donkeys (4/91). No donkeys less than 24 months of age (129) were seropositive, suggesting postnatal transmission of infection. Domestic cats were present on six of the eight farms. Three cats from one farm had MAT titers of 200. Viable T. gondii was isolated from the hearts of two cats, but not from brain tissues. Genotyping of isolate DNA extracted from culture-derived tachyzoites using 10 PCR-restriction fragment length polymorphism (RFLP) markers (SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, PK1, L358 and Apico loci) revealed that both isolates were clonal Type II (ToxoDB PCR-RFLP genotype #1). This is the first serological survey for T. gondii in donkeys in the United States, and suggests that donkey milk and meat should be considered as a potential source for human infection. The role of barn cats in the transmission of T. gondii to donkeys on farms warrents further investigation. Copyright © 2013 Elsevier B.V. All rights reserved.

  18. Seroepidemiology of Toxoplasma gondii in pregnant women in Aguascalientes City, Mexico: a cross-sectional study.

    Science.gov (United States)

    Alvarado-Esquivel, Cosme; Terrones-Saldívar, María Del Carmen; Hernández-Tinoco, Jesús; Muñoz-Terrones, María Daniela Enriqueta; Gallegos-González, Roberto Oswaldo; Sánchez-Anguiano, Luis Francisco; Reyes-Robles, Martha Elena; Jaramillo-Juárez, Fernando; Liesenfeld, Oliver; Estrada-Martínez, Sergio

    2016-07-01

    We determined the seroprevalence and correlates of Toxoplasma gondii infection in pregnant women in Aguascalientes City, Mexico. A cross-sectional survey. Pregnant women were enrolled in the central Mexican city of Aguascalientes. We studied 338 pregnant women who attended prenatal care in 3 public health centres. Women were examined for IgG/IgM antibodies to T. gondii by using commercially available enzyme immunoassays, and an avidity test. Multiple analyses were used to determine the association of T. gondii seropositivity with the characteristics of the pregnant women. Of the 338 pregnant women studied, 21 (6.2%) had IgG antibodies to T. gondii, and 1 (4.8%) of them was also positive for IgM antibodies to T. gondii. Avidity of IgG antibodies to T. gondii was high in the IgM-positive sample. Logistic regression analysis of sociodemographic, behavioural and housing variables showed that T. gondii seropositivity was associated with white ethnicity (OR=149.4; 95% CI 10.8 to 2054.1; pprimary infection. Factors associated with T. gondii exposure found in this study, including food hygiene, may be useful to determine preventive measures against T. gondii infection and its sequelae. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  19. Seroprevalence of Toxoplasma gondii Infection in Sows in Hunan Province, China

    Directory of Open Access Journals (Sweden)

    Ying Xu

    2014-01-01

    Full Text Available Toxoplasma gondii infections are prevalent in animals and humans worldwide. Although the prevalence of T. gondii has been reported in many animals in China, little is known of T. gondii infection in sows. Antibodies to T. gondii in sows in Hunan province, subtropical China, were examined using indirect hemagglutination test (IHAT. Overall, 31.3% (373/1191 of the examined sows were seropositive for T. gondii. Among 11 representative regions of Hunan province, the seroprevalence ranged from 14.8% to 45.1%. In addition, the T. gondii seroprevalence was higher in summer (37.4% and autumn (34.9% than in spring (24.6% and winter (23.9%. Regarding different antibody titers, the seroprevalence ranged from 1.8% (titer ≥ 1 : 1024 to 17.4% (titer = 1 : 64. The findings of the present investigation revealed the high seroprevalence of T. gondii in sows in Hunan province, China, which poses a potential risk for T. gondii infection in humans and animals in this province. Therefore, effective measures should be taken to prevent and control toxoplasmosis of pigs in this province. This is the first report of the comprehensive survey of T. gondii seroprevalence in sows in Hunan Province, subtropical China.

  20. Toxoplasmosis and Polygenic Disease Susceptibility Genes: Extensive Toxoplasma gondii Host/Pathogen Interactome Enrichment in Nine Psychiatric or Neurological Disorders

    Directory of Open Access Journals (Sweden)

    C. J. Carter

    2013-01-01

    Full Text Available Toxoplasma gondii is not only implicated in schizophrenia and related disorders, but also in Alzheimer's or Parkinson's disease, cancer, cardiac myopathies, and autoimmune disorders. During its life cycle, the pathogen interacts with ~3000 host genes or proteins. Susceptibility genes for multiple sclerosis, Alzheimer's disease, schizophrenia, bipolar disorder, depression, childhood obesity, Parkinson's disease, attention deficit hyperactivity disorder (multiple sclerosis, and autism (, but not anorexia or chronic fatigue are highly enriched in the human arm of this interactome and 18 (ADHD to 33% (MS of the susceptibility genes relate to it. The signalling pathways involved in the susceptibility gene/interactome overlaps are relatively specific and relevant to each disease suggesting a means whereby susceptibility genes could orient the attentions of a single pathogen towards disruption of the specific pathways that together contribute (positively or negatively to the endophenotypes of different diseases. Conditional protein knockdown, orchestrated by T. gondii proteins or antibodies binding to those of the host (pathogen derived autoimmunity and metabolite exchange, may contribute to this disruption. Susceptibility genes may thus be related to the causes and influencers of disease, rather than (and as well as to the disease itself.

  1. A novel multifunctional oligonucleotide microarray for Toxoplasma gondii

    Directory of Open Access Journals (Sweden)

    Chen Feng

    2010-10-01

    Full Text Available Abstract Background Microarrays are invaluable tools for genome interrogation, SNP detection, and expression analysis, among other applications. Such broad capabilities would be of value to many pathogen research communities, although the development and use of genome-scale microarrays is often a costly undertaking. Therefore, effective methods for reducing unnecessary probes while maintaining or expanding functionality would be relevant to many investigators. Results Taking advantage of available genome sequences and annotation for Toxoplasma gondii (a pathogenic parasite responsible for illness in immunocompromised individuals and Plasmodium falciparum (a related parasite responsible for severe human malaria, we designed a single oligonucleotide microarray capable of supporting a wide range of applications at relatively low cost, including genome-wide expression profiling for Toxoplasma, and single-nucleotide polymorphism (SNP-based genotyping of both T. gondii and P. falciparum. Expression profiling of the three clonotypic lineages dominating T. gondii populations in North America and Europe provides a first comprehensive view of the parasite transcriptome, revealing that ~49% of all annotated genes are expressed in parasite tachyzoites (the acutely lytic stage responsible for pathogenesis and 26% of genes are differentially expressed among strains. A novel design utilizing few probes provided high confidence genotyping, used here to resolve recombination points in the clonal progeny of sexual crosses. Recent sequencing of additional T. gondii isolates identifies >620 K new SNPs, including ~11 K that intersect with expression profiling probes, yielding additional markers for genotyping studies, and further validating the utility of a combined expression profiling/genotyping array design. Additional applications facilitating SNP and transcript discovery, alternative statistical methods for quantifying gene expression, etc. are also pursued at

  2. Toxoplasma gondii DNA detection with a magnetic molecular beacon probe

    Science.gov (United States)

    Xu, Shichao; Yao, Cuicui; Wei, Shuoming; Zhang, Jimei; Dai, Zhao; Zheng, Guo; Sun, Bo; Han, Qing; Hu, Fei; Zhou, Hongming

    2008-12-01

    Toxoplasma Gondii infection is widespread in humans worldwide and reported infection rates range from 3%-70%, depending on the populations or geographic areas, and it has been recognized as a potential food safety hazard in our daily life. A magnetic molecular beacon probe (mMBP), based on theory of fluorescence resonance energy transfer (FRET), was currently reported to detect Toxoplasma Gondii DNA. Nano-sized Fe3O4 were primarily prepared by coprecipitation method in aqueous phase with NaOH as precipitator, and was used as magnetic core. The qualified coreshell magnetic quantum dots (mQDs), i.e. CdTe(symbol)Fe3O4, were then achieved by layer-by-layer method when mol ratio of Fe3O4/CdTe is 1/3, pH at 6.0, 30 °C, and reactant solution was refluxed for 30 min, the size of mQDs were determined to be 12-15 nm via transmission electron microscopy (TEM). Over 70% overlap between emission spectrum of mQDs and absorbance spectrum of BHQ-2 was observed, this result suggests the synthesized mQDs and BHQ-2 can be utilized as energy donor and energy acceptor, respectively. The sensing probe was fabricated and a stem-loop Toxoplasma Gondii DNA oligonucleotide was labeled with mQDs at the 5' end and BHQ-2 at 3' end, respectively. Target Toxoplasma gondii DNA was detected under conditions of 37 °C, hybridization for 2h, at pH8.0 in Tris-HCl buffer. About 30% recovery of fluorescence intensity was observed via fluorescence spectrum (FS) after the Toxoplasma gondii DNA was added, which suggested that the Toxoplasma Gondii DNA was successfully detected. Specificity investigation of the mMBP indicated that relative low recovery of fluorescence intensity was obtained when the target DNA with one-base pair mismatch was added, this result indicated the high specificity of the sensing probe. Our research simultaneously indicated that mMBP can be conveniently separated from the unhybridized stem-loop DNA and target DNA, which will be meaningful in DNA sensing and purification process.

  3. MHC I presentation of Toxoplasma gondii immunodominant antigen does not require Sec22b and is regulated by antigen orientation at the vacuole membrane.

    Science.gov (United States)

    Buaillon, Célia; Guerrero, Nestor A; Cebrian, Ignacio; Blanié, Sophie; Lopez, Jodie; Bassot, Emilie; Vasseur, Virginie; Santi-Rocca, Julien; Blanchard, Nicolas

    2017-07-01

    The intracellular Toxoplasma gondii parasite replicates within a parasitophorous vacuole (PV). T. gondii secretes proteins that remain soluble in the PV space, are inserted into PV membranes or are exported beyond the PV boundary. In addition to supporting T. gondii growth, these proteins can be processed and presented by MHC I for CD8 + T-cell recognition. Yet it is unclear whether membrane binding influences the processing pathways employed and if topology of membrane antigens impacts their MHC I presentation. Here we report that the MHC I pathways of soluble and membrane-bound antigens differ in their requirement for host ER recruitment. In contrast to the soluble SAG1-OVA model antigen, we find that presentation of the membrane-bound GRA6 is independent from the SNARE Sec22b, a key molecule for transfer of host endoplasmic reticulum components onto the PV. Using parasites modified to secrete a transmembrane antigen with opposite orientations, we further show that MHC I presentation is highly favored when the C-terminal epitope is exposed to the host cell cytosol, which corresponds to GRA6 natural orientation. Our data suggest that the biochemical properties of antigens released by intracellular pathogens critically guide their processing pathway and are valuable parameters to consider for vaccination strategies. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Effects of ionizing radiation over the structure, metabolism and infectivity of a pathogenic protozoan, Toxoplasma gondii; Efeitos da radiacao ionizante sobre a estrutura, metabolismo e infectividade de um protozoario patogenico, Toxoplasma gondii (Nicole and Manceau, 1908)

    Energy Technology Data Exchange (ETDEWEB)

    Hiramoto, Roberto Mitsuyoshi

    1998-07-01

    The intracellular parasite Toxoplasma gondii (Apicomplexa), has as definitive host domestic and wild felines and as intermediate hosts most species of mammals and birds, Including man. The infection in man is usually asymptomatic, but can become a severe and lethal illness in some special groups like the fetus of primoinfected pregnant woman, or in AIDS and transplanted patients. The transmission is due to ingestion of food or water contaminated with oocysts from cat feces as well as raw or rare cooked cyst containing meet. There is no available vaccine against toxoplasmosis, with some reports of the use ionizing radiation in order to attenuate or suppress the parasite. These studies are promising, but more research is needed to optimize the radiation process and to clarify those alterations caused on T gondii.Using a increasing doses of {sup 60} Co irradiation on T.gondii tachyzoites, we studied many parameters such as morphology, both at optical and electron microscopy level, detection of DNA fragmentation, metabolism alterations (cellular oxidative burst, protein, nucleic acids and DNA synthesis), determination of the parasite survival both in in vivo and in vitro models, antigenicity and immunogenicity after the process, cellular invasion and irradiated tachyzoite induced protection. After definition of 200 Gy of {sup 60} Co irradiation as the lower radiation dose that suppress parasite growth in vitro and in vivo, we found no detectable changes in parasite viability, its cell invasion capacity or in its structural proteins. DNA fragmentation like apoptosis or alterations of the parasite metabolism were similarly not affected by radiation. Mice infection with irradiated parasites induce partial protection when these animals were re-inoculated with non irradiated virulent parasites, inducing greater specific IgG levels as well as a longer survival. Irradiated T.gondii maintains its the ability of invasion, even under radiation effects. Based on our results we

  5. Seroprevalence of Toxoplasma gondii infection in goats from the south-west region of Poland and the detection of T. gondii DNA in goat milk.

    Science.gov (United States)

    Sroka, Jacek; Kusyk, Pawel; Bilska-Zajac, Ewa; Karamon, Jacek; Dutkiewicz, Jacek; Wojcik-Fatla, Angelina; Zajac, Violetta; Stojecki, Krzysztof; Rozycki, Miroslaw; Cencek, Tomasz

    2017-07-11

    Toxoplasma gondii (Nicolle et Manceaux, 1908) is an obligatory intracellular protozoan parasite prevalent in animals and humans worldwide having medical and veterinary importance on account of causing abortion or congenital disease in intermediate hosts, including man. Since T. gondii has already been identified in the milk of goats, Capra aegagrus hircus (Linnaeus), the possibility of acquiring infection by ingesting unpasteurised goat milk should be taken into consideration. Thus, the aim of the present study was to determine the presence of T. gondii DNA in goat milk. First, 73 goats (females) from 36 farms located in Poland were examined serologically by direct agglutination test (DAT) to estimate the T. gondii serological status. Milk samples from 60 selected lactating females were examined for the presence of T. gondii DNA by Real time PCR and nested PCR (B1 gene). To estimate the clonal type of detected T. gondii, multiplex PCR was performed using 6 markers. In DAT, positive results were found in 70% of 73 goats. Among examined 60 milk samples, 65% were positive in Real time PCR and 43% in nested PCR. It is noteworthy that 11 samples positive in PCR were collected from seronegative goats. The multilocus PCR analysis mostly revealed the occurrence of genotype III, which is relatively rare in Europe. The recorded high prevalence of anti-Toxoplasma antibodies in tested goats (70%), associated with a high prevalence of T. gondii DNA in goat milk samples (65%), indicates a potential risk of the parasite transmission through goat milk ingestion.

  6. Isolation and characterization of new genetic types of toxoplasma gondii and prevalence of trichinella murrelli from black bear (Ursus americanus)

    Science.gov (United States)

    Black bears (Ursus americanus) are hosts for two important zoonotic parasites, Toxoplasma gondii and Trichinella spp. and bears are hunted for human consumption in the USA. Little is known of the genetic diversity of T. gondii circulating in wildlife. In the present study, antibodies to T. gondii we...

  7. Serological survey and risk factors for Toxoplasma gondii in domestic ducks and geese in Lower Saxony, Germany

    Science.gov (United States)

    To obtain estimates for the prevalence of Toxoplasma gondii infection in ducks and geese in Germany, enzyme-linked immunosorbent assays (ELISA) were established based on affinity-purified T. gondii tachyzoite surface antigen 1 (TgSAG1) and used to examine duck and goose sera for T. gondii -specific ...

  8. Prevalence and genetic characterization of Toxoplasma gondii in free-range chickens from grocery stores and farms

    Science.gov (United States)

    Chickens are considered important in the epidemiology of Toxoplasma gondii. Chicken hearts (n=1185) obtained from the local markets were tested for T. gondii infection. Antibodies to T. gondii were assayed in fluid removed from the heart cavity using the modified agglutination test (MAT) at 1:5, 1:2...

  9. Quantifying the risk of human Toxoplasma gondii infection due to consumption of fresh pork in the United States

    Science.gov (United States)

    Toxoplasma gondii is one of the leading foodborne pathogens in the United States. The Centers for Disease Control and Prevention (CDC) reported that T. gondii accounts for 24% of deaths due to foodborne illness in the United States. Consumption of undercooked pork products in which T. gondii has enc...

  10. Risk factors of Toxoplasma gondii infection in hunting, pet and watchdogs from Southern Spain and Northern Africa

    Science.gov (United States)

    Dogs can act as reservoirs of Toxoplasma gondii infections for humans and other hosts. Here we determined seroprevalence and risk factors of T. gondii infection in dogs from Andalusia (Southern Spain) and Ceuta (Northern Africa). Antibodies to T. gondii were detected in 235 out of 769 dogs (30.6%; C...

  11. Seroprevalence and genetic characterization of Toxoplasma gondii in three species of pet birds in China.

    Science.gov (United States)

    Cong, Wei; Meng, Qing-Feng; Song, Hui-Qun; Zhou, Dong-Hui; Huang, Si-Yang; Qian, Ai-Dong; Su, Chunlei; Zhu, Xing-Quan

    2014-04-01

    Toxoplasmosis, caused by the protozoan parasite Toxoplasma gondii, is one of the most common zoonosis worldwide, affecting a wide range of warm-blooded mammals and birds worldwide. However, no information on T. gondii infection in pet birds in China is available. Therefore, this study was performed to determine the prevalence of T. gondii infection in pet birds in Gansu province, China. A total of 687 blood samples were collected from pet birds (Carduelis spinus, Alauda gulgula, Cocothraustes migratorlus) in three representative administrative regions in Gansu province, northwest China between August 2011 and September 2012 T. gondii antibodies were determined using the modified agglutination test (MAT). Genomic DNA was extracted from the brain tissues of seropositive pet birds and T. gondii B1 gene was amplified using a semi-nested PCR.DNA samples giving positive B1 amplification were then genetically characterized using multi-locus PCR-RFLP. The overall T. gondii seroprevalence was 11.21% (77/687). C. spinus had the highest T. gondii seroprevalence (11.65%), followed by A. arvensis (11.39%) and C. migratorlus (5.26%), these differences were not statistically significant (P > 0.05). Of 77 DNA samples, 8 were positive for the T. gondii B1 gene, four showed complete genotyping results. Only one genotype (the Type II variant: ToxoDB genotype #3) was identified. The results of the present survey indicated the presence of T. gondii infection in pet birds in Gansu province, China. These data provide base-line information for the execution of control strategies against T. gondii infection in pet birds. To our knowledge, this is the first report documenting the occurrence of T. gondii prevalence and genotype in pet birds in China.

  12. First report of Toxoplasma gondii seroprevalence in peafowls in Yunnan Province, Southwestern China

    Directory of Open Access Journals (Sweden)

    Tian Yi-Ming

    2012-09-01

    Full Text Available Abstract Background Toxoplasma gondii is an intracellular protozoan parasite infecting almost all warm-blooded animals, including birds, with a worldwide distribution. Surveys of T. gondii infection in wild birds have been reported extensively in the world, but little is known of T. gondii infection in peafowls worldwide. This study was performed to determine the seroprevalence of T. gondii infection in peafowls in Yunnan Province, southwestern China. Methods Sera from 277 peafowls, including 272 blue peafowls (Pavo cristatus and 5 green peafowls (Pavo muticus originated from two geographic areas in Yunnan Province were assayed for T. gondii antibodies using the modified agglutination test (MAT. Results Specific T. gondii antibodies were detected in 35 of 277 (12.64% peafowls (MAT titer ≥ 1:5. Seropositive birds were found in both species, 33 in 272 blue peafowls and 2 in 5 green peafowls. There was no significant difference in T. gondii seroprevalence between the adolescent birds (6.74% and the adult birds (6.67% (P > 0.05. The geographical origins of peafowls was found to be highly associated with T. gondii infection in the present study, a statistically significant difference in T. gondii seropositivity was observed between peafowls from Kunming (31.08% and those from Xishuangbanna Dai Autonomous Prefecture (5.91% (OR = 10.956, 95% CI = 1.632-73.545, P = 0.014. Statistical analyses showed that there were no significant interactions between ages and geographical origins of peafowls (P > 0.05. Conclusions The results of the present survey indicated that infection of peafowls with T. gondii is widespread in Yunnan Province, which has significant public health concerns and implications for prevention and control of toxoplamosis in this province. To our knowledge, this is the first seroprevalence report of T. gondii infection in China’s southwestern Yunnan Province.

  13. First report of Toxoplasma gondii seroprevalence in peafowls in Yunnan Province, Southwestern China.

    Science.gov (United States)

    Tian, Yi-Ming; Dai, Fei-Yan; Huang, Si-Yang; Deng, Zu-Hong; Duan, Gang; Zhou, Dong-Hui; Yang, Jian-Fa; Weng, Ya-Biao; Zhu, Xing-Quan; Zou, Feng-Cai

    2012-09-19

    Toxoplasma gondii is an intracellular protozoan parasite infecting almost all warm-blooded animals, including birds, with a worldwide distribution. Surveys of T. gondii infection in wild birds have been reported extensively in the world, but little is known of T. gondii infection in peafowls worldwide. This study was performed to determine the seroprevalence of T. gondii infection in peafowls in Yunnan Province, southwestern China. Sera from 277 peafowls, including 272 blue peafowls (Pavo cristatus) and 5 green peafowls (Pavo muticus) originated from two geographic areas in Yunnan Province were assayed for T. gondii antibodies using the modified agglutination test (MAT). Specific T. gondii antibodies were detected in 35 of 277 (12.64%) peafowls (MAT titer ≥ 1:5). Seropositive birds were found in both species, 33 in 272 blue peafowls and 2 in 5 green peafowls. There was no significant difference in T. gondii seroprevalence between the adolescent birds (6.74%) and the adult birds (6.67%) (P > 0.05). The geographical origins of peafowls was found to be highly associated with T. gondii infection in the present study, a statistically significant difference in T. gondii seropositivity was observed between peafowls from Kunming (31.08%) and those from Xishuangbanna Dai Autonomous Prefecture (5.91%) (OR = 10.956, 95% CI = 1.632-73.545, P = 0.014). Statistical analyses showed that there were no significant interactions between ages and geographical origins of peafowls (P > 0.05). The results of the present survey indicated that infection of peafowls with T. gondii is widespread in Yunnan Province, which has significant public health concerns and implications for prevention and control of toxoplamosis in this province. To our knowledge, this is the first seroprevalence report of T. gondii infection in China's southwestern Yunnan Province.

  14. The lytic cycle of Toxoplasma gondii: 15 years later

    Science.gov (United States)

    Blader, Ira; Coleman, Bradley; Chen, Chun-Ti; Gubbels, Marc-Jan

    2015-01-01

    Toxoplasmosis is the clinical and pathological consequence of acute infection with the obligate intracellular apicomplexan parasite Toxoplasma gondii. Symptoms result from tissue destruction that accompanies lytic parasite growth. This review updates current understanding of the host cell invasion, parasite replication and eventual egress that comprise the lytic cycle, as well as the ways T. gondii manipulates host cells to assure survival. Since the publication of a previous iteration of this review 15 years ago, important advances have been made in our molecular understanding of parasite growth and mechanisms of host cell egress, and knowledge of the parasite’s manipulation of the host has rapidly progressed. Here we cover molecular advances and current conceptual frameworks that include each of these topics, with an eye to what might be known 15 years from now. PMID:26332089

  15. Seroprevalence of Toxoplasma gondii infection among pregnant women in Cameroon

    Directory of Open Access Journals (Sweden)

    Anna L. Njunda

    2011-09-01

    Full Text Available Toxoplasmosis is caused by an intracellular protozoan, Toxoplasma gondii, which has a wide geographical distribution. The congenital form results in a gestational form that can present a temporary parasiteamia that will infect the fetus. For this reason early diagnosis in pregnancy is highly desirable, allowing prompt intervention in cases of infection. The aim of this study was to determine the seroprevalence of Toxoplasma gondii antibodies among pregnant women attending the Douala General Hospital. The study was carried out between March and July 2009, whereby 110 pregnant women were tested for IgG and IgM antibodies and information about eating habits and hygienic conditions was collected using a questionnaire. These women’s ages ranged from 20-44 years old with an average of 29.9 years; the overall IgG and IgM seroprevalence was 70% and 2.73 % respectively. Seroprevalence was significantly high amongst women who ate raw vegetables (76.39%, P<0.05 and there was a significant trend towards a higher seroprevalence in women who did not have a good source of water (75.58%, P<0.05. This research showed that consumption raw vegetables and poor quality drinking water are two risk factors associated with Toxoplasma gondii infection amongst pregnant women attending the Douala General Hospital in Cameroon.

  16. Subversion of innate and adaptive immune responses by Toxoplasma gondii.

    Science.gov (United States)

    Lang, Christine; Gross, Uwe; Lüder, Carsten G K

    2007-01-01

    The intracellular apicomplexan parasite Toxoplasma gondii is able to survive and persist in immunocompetent intermediate hosts for the host's life span. This is despite the induction of a vigorous humoral and -- more importantly -- cell-mediated immune response during infection. In order to establish and maintain such chronic infections, however, T. gondii has evolved multiple strategies to avoid or to interfere with potentially efficient anti-parasitic immune responses of the host. Such immune evasion includes (1) indirect mechanisms by altering the expression and secretion of immunomodulatory cytokines or by altering the viability of immune cells and (2) direct mechanisms by establishing a lifestyle within a suitable intracellular niche and by interference with intracellular signaling cascades, thereby abolishing a number of antimicrobial effector mechanisms of the host. Despite the parasite's ability to interfere successfully with the host's efforts to eradicate the infection, the immune response is, however, not completely abrogated but is rather partially diminished after infection. T. gondii thus keeps a delicate balance between induction and suppression of the host's immune response in order to guarantee the survival of the host as a safe harbor for parasite development and to allow its transmission to the definitive host.

  17. Analysis of Structures and Epitopes of Surface Antigen Glycoproteins Expressed in Bradyzoites of Toxoplasma gondii

    Directory of Open Access Journals (Sweden)

    Hua Cong

    2013-01-01

    Full Text Available Toxoplasma gondii is a protozoan parasite capable of infecting humans and animals. Surface antigen glycoproteins, SAG2C, -2D, -2X, and -2Y, are expressed on the surface of bradyzoites. These antigens have been shown to protect bradyzoites against immune responses during chronic infections. We studied structures of SAG2C, -2D, -2X, and -2Y proteins using bioinformatics methods. The protein sequence alignment was performed by T-Coffee method. Secondary structural and functional domains were predicted using software PSIPRED v3.0 and SMART software, and 3D models of proteins were constructed and compared using the I-TASSER server, VMD, and SWISS-spdbv. Our results showed that SAG2C, -2D, -2X, and -2Y are highly homologous proteins. They share the same conserved peptides and HLA-I restricted epitopes. The similarity in structure and domains indicated putative common functions that might stimulate similar immune response in hosts. The conserved peptides and HLA-restricted epitopes could provide important insights on vaccine study and the diagnosis of this disease.

  18. Seroprevalence and risk factors of Toxoplasma gondii infection among pregnant women in south western, Saudi Arabia.

    Science.gov (United States)

    Almushait, Mona A; Dajem, Saad M Bin; Elsherbiny, Nahla M; Eskandar, Mamdoh A; Al Azraqi, Tarik A; Makhlouf, Laila M

    2014-03-01

    This study aimed to determine the seroprevalence of Toxoplasma gondii in pregnant women in the south western region of Saudi Arabia and to find out the possible risk factors that may lead to infection. This cross sectional hospital based study was carried out at three hospitals in the south western region of Saudi Arabia from January 2008 to August 2010. Blood samples from 487 pregnant women were collected and used to detect anti-T. gondii antibodies IgM and IgG by enzyme linked immunosorbent assay (ELISA). A questionnaire interview was carried out to ask about some risk factors of infection. Among the 487 studied pregnant women, 38.8 % were seropositive for anti T. gondii IgG while 6.2 % were positive for anti T. gondii IgM and 3.3 % were positive for both anti T. gondii IgG & IgM. The only risk factor associated with seropositive anti T. gondii IgM was the history of the intake of immunosuppressive drugs. Regarding anti T. gondii IgG seropositivity, it was found to increase significantly with increased age, number of gravida and parities, and previous history of toxoplasmosis. The seroprevalence of T. gondii IgG & IgM by ELISA among pregnant women in the south western region of Saudi Arabia is considerable with few identifiable significant risk factors reported.

  19. 97 original article toxoplasma gondii infection in hiv/aids: prevalence ...

    African Journals Online (AJOL)

    Living in proximity with cat was positively associated with T. gondii infection (P= 0.01). ... eyes and lungs. T. gondii encephalitis could be via acute infection or reactivation of latent infection among immune suppressed persons including those with acquired immuno-deficiency syndrome, those with immunosuppressive ...

  20. A quantitative microbial risk assessment for meatborne Toxoplasma gondii infection in The Netherlands

    NARCIS (Netherlands)

    Opsteegh, M.; Prickaerts, S.; Frankena, K.; Evers, E.G.

    2011-01-01

    Toxoplasma gondii is an important foodborne pathogen, and the cause of a high disease burden due to congenital toxoplasmosis in The Netherlands. The aim of this study was to quantify the relative contribution of sheep, beef and pork products to human T. gondii infections by Quantitative Microbial

  1. Design of a Risk based Control System for Toxoplasma gondii in a pork supply chain

    NARCIS (Netherlands)

    Heres, L.; Swanenburg, M.; Koeijer, de A.A.; Boender, G.J.; Oorburg, D.; Urlings, B.; Wisselink, H.J.

    2015-01-01

    Toxoplasma gondii is recognized as one of the major foodborne pathogens. The European Food Safety Authority (EFSA) concluded that T. gondii is one of the public health hazards in pigs to be covered within a modern meat inspection and advised to include serological testing of pigs and audits of pig

  2. First genetic characterization of Toxoplasma gondii infection in Arctic foxes (Vulpes lagopus) in China.

    Science.gov (United States)

    Zhang, Xiao-Xuan; Cong, Wei; Ma, Jian-Gang; Lou, Zhi-Long; Zhao, Quan; Meng, Qing-Feng; Qian, Ai-Dong; Zhu, Xing-Quan

    2016-10-01

    Toxoplasma gondii can infect virtually all warm-blooded animals including foxes. However, little is known of the molecular epidemiology and genotypes of T. gondii infecting foxes in China. Therefore, the present study characterized T. gondii genotypes in foxes in China for the first time. During November 2014 to October 2015, brain tissue samples collected from 264 Arctic foxes (Vulpes lagopus) in Jilin, Heilongjiang and Shandong provinces were used to detect the T. gondii B1 gene by a semi-nested PCR, and the positive samples were genotyped at 10 nuclear loci (i.e., SAG1, alternative SAG2, 5'-and 3'-SAG2, SAG3, L358, BTUB, c22-8, GRA6, c29-2, PK1) and an apicoplast locus (Apico) by multi-locus PCR-RFLP technology. Twenty-one (7.96%) samples from 264 foxes were positive for T. gondii B1 gene. T. gondii infection in male and female foxes was 7.14% and 8.70%, respectively. The highest infection rate (11.86%) was detected in foxes from Shandong, followed by foxes from Jilin (6.49%) and Heilongjiang (2.90%). Two genotypes (ToxoDB#9 and ToxoDB#10) were identified. This is the first genetic characterization of T. gondii from foxes in China, which provides basic data for the surveillance and control of T. gondii infection in foxes, other animals and humans. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Prevalence of Toxoplasma gondii IgG and IgM and associated risk ...

    African Journals Online (AJOL)

    Prevalence of Toxoplasma gondii IgG and IgM and associated risk factors among HIV-positive and HIV-negative patients in Vhembe district of South Africa. ... shown a high prevalence of T. gondii (IgG) among patients attending different HIV clinics in the Vhembe district with no current infections among pregnant women.

  4. Prevalence of Toxoplasma gondii antibodies in stray and owned dogs of Grenada, West Indies

    Directory of Open Access Journals (Sweden)

    Ravindra N. Sharma

    2014-09-01

    Full Text Available Aim: This serological survey was undertaken to estimate the prevalence of Toxoplasma gondii in two populations of dogs (stray and owned dogs in Grenada. Dogs get infected with oocysts voided from cats, definitive hosts of T. gondii. In dogs, T. gondii causes subclinical to clinical disease. Earlier studies conducted in Grenada on a small population of owned dogs showed evidence of exposure to T. gondii. Materials and Methods: Antibodies to T. gondii were determined in serum samples from 625 dogs (368 stray and 257 owned dogs from around all six parishes in Grenada, West Indies, using an indirect enzyme linked immunosorbent assay. Results: Antibodies to T. gondii were found in 123 (33.4%; 95% confidence interval [CI]: 28.58-38.22% of stray dogs and in 64 (25%; 95% CI: 19.71-30.29% of the owned dogs. Seropositivity was higher in stray dogs than in pet dogs (p=0.026. Whereas, there was no sex predisposition to seropositivity in owned dogs (p=1.0, female stray dogs showed a higher prevalence than male stray dogs (p=0.04. Conclusion: These results support previous findings that T. gondii is prevalent in Grenada. In this study, overall seropositivity for T. gondii in dogs in Grenada is lower than noted in 2008, but is still higher in stray dogs than in owned dogs.

  5. Inactivation of Toxoplasma gondii on blueberries using low dose irradiation without affecting quality

    Science.gov (United States)

    Toxoplasma gondii is a common protozoan parasite, whose environmentally-resistant stage, the oocyst, can contaminate irrigation water and fresh edible produce. Current washing steps in produce processing may not be effective for eliminating T. gondii from at-risk varieties of produce. The objective ...

  6. Transplacental transmission of Toxoplasma gondii in minipigs infected with strains of different virulence

    DEFF Research Database (Denmark)

    Jungersen, Gregers; Bille-Hansen, Vivi; Jensen, Lene Bai

    2001-01-01

    Infections with the Zoonotic protozoan Toxoplasma gondii during pregnancy can result in severe fetal infections. To investigate the use of pigs as animal models for congenital toxoplasmosis, tachyzoites of 5 T. gondii strains, with low to intermediate virulence in mice, were intravenously...... animal models fur studies of transplacental transmission and pathogenesis of congenital toxoplasmosis....

  7. Sequence variation in TgROP7 gene among Toxoplasma gondii ...

    African Journals Online (AJOL)

    Toxoplasma gondii can infect a wide range of hosts including mammals and birds, causing toxoplasmosis which is one of the most common parasitic zoonoses worldwide. The present study examined sequence variation in rhoptry 7 (ROP7) gene among different T. gondii isolates from different hosts and geographical ...

  8. Transplacental transmission of Toxoplasma gondii in minipigs infected with strains of different virulence

    DEFF Research Database (Denmark)

    Jungersen, Gregers; Bille-Hansen, Vivi; Jensen, Lene Bai

    2001-01-01

    Infections with the Zoonotic protozoan Toxoplasma gondii during pregnancy can result in severe fetal infections. To investigate the use of pigs as animal models for congenital toxoplasmosis, tachyzoites of 5 T. gondii strains, with low to intermediate virulence in mice, were intravenously...

  9. The role of rodents and shrews in the transmission of Toxoplasma gondii to pigs

    NARCIS (Netherlands)

    Kijlstra, A.; Meerburg, B.G.; Cornelissen, J.B.W.J.; Craeye, de S.; Vereijken, P.F.G.; Jongert, E.

    2008-01-01

    Inadequate rodent control is considered to play a role in Toxoplasma gondii infection of pigs. This issue was addressed in the current study by combining a 4-month rodent control campaign and a 7-month longitudinal analysis of T. gondii seroprevalence in slaughter pigs. Three organic pig farms with

  10. Toxoplasma gondii seroprevalence in free-ranging moose (Alces alces) hunted for human consumption in Estonia

    DEFF Research Database (Denmark)

    Remes, Noora; Kärssin, Age; Must, Kärt

    2018-01-01

    In Estonia, northeastern Europe, antibodies against Toxoplasma gondii are common in many host species, including wildlife, domestic animals, and humans. Our nationwide study aimed to estimate T. gondii seroprevalence and its geographical distribution, and to evaluate plausible risk factors for se...

  11. Toxoplasmosis in dogs: First report of Toxoplasma gondii infection in any animal species in Angola

    Science.gov (United States)

    Despite the worldwide importance of zoonotic parasite Toxoplasma gondii nothing is known of toxoplasmosis in animals in Angola. The present study aimed at estimating the seroprevalence and also assessing correlates of T. gondii infection in pet dogs from Luanda, Angola. Dogs (n = 103) brought to a v...

  12. Seroprevalence of Toxoplasma gondii infection in captive mammals in three zoos in Mexico City, Mexico

    Science.gov (United States)

    Antibodies to Toxoplasma gondii were determined in 167 mammals in 3 zoos in Mexico City, Mexico using the modified agglutination test (MAT). Overall, antibodies to T. gondii were found in 89 (53.3%) of the 167 animals tested. Antibodies were found in 35 of 43 wild Felidae: 2 of 2 bobcats (Lynx rufus...

  13. Changing climate-changing pathogens: Toxoplasma gondii in North-Western Europe

    NARCIS (Netherlands)

    Meerburg, B.G.; Kijlstra, A.

    2009-01-01

    In this review, we describe the effects of global climate change for one specific pathogen: the parasite Toxoplasma gondii. It is postulated that an increase of T. gondii prevalence in humans can occur in some regions of North-Western Europe as a result of changing environmental conditions. Such a

  14. Seroprevalence of Toxoplasma gondii and Neospora caninum in north-eastern Atlantic Harbor seal

    Science.gov (United States)

    Antibodies to Toxoplasma gondii and Neospora caninum were determined in serum samples from 47 grey seals (Halichoerus grypus) and 56 harbor seals (Phoca vitulina vitulina) from the Atlantic coasts of United Kingdom and France. Antibodies to T. gondii assayed by the modified agglutination test (MAT) ...

  15. Sequence variation in TgROP7 gene among Toxoplasma gondii ...

    African Journals Online (AJOL)

    Yomi

    2012-03-27

    Mar 27, 2012 ... Toxoplasma gondii can infect a wide range of hosts including mammals and birds, causing toxoplasmosis which is one of the most common parasitic zoonoses worldwide. The present study examined sequence variation in rhoptry 7 (ROP7) gene among different T. gondii isolates from different hosts and ...

  16. Toxoplasma gondii IgG antibodies in HIV/AIDS patients attending ...

    African Journals Online (AJOL)

    Background: Toxoplasmosis is caused by Toxoplasma gondii, a parasite that gradually evolved to be the most opportunistic parasite that complicates the course of HIV/AIDS in developing countries. Aim: This study was undertaken to investigate the presence of Toxoplasma gondii IgG antibodies in HIVinfected patients ...

  17. Seroepidemiology of Toxoplasma gondii infection in bats from São Paulo city, Brazil

    Science.gov (United States)

    Toxoplasmosis is a parasitic zoonosis caused by Toxoplasma gondii with a worldwide distribution. The aim of this study was to determine the frequency of IgG anti-T. gondii antibodies in bats from São Paulo city, Brazil. A total of 616 serum samples were collected from 22 species of bats. Anti-T. gon...

  18. Seroprevalence of Toxoplasma gondii infection in domestic sheep in Oaxaca State, Mexico

    Science.gov (United States)

    The seroprevalence of Toxoplasma gondii infection in sheep in southern Mexico is largely unknown. Antibodies to T. gondii were determined in serum samples of 429 sheep from 4 farms in 2 geographical regions in Oaxaca State, Mexico using the modified agglutination test (MAT); 99 (23.1%) of the 429 sh...

  19. Determining UV Inactivation of Toxoplasma gondii Oocysts by Using Cell Culture and a Mouse Bioassay

    Science.gov (United States)

    The effect of UV exposure on Toxoplasma gondii oocysts has not been completely defined for use in water disinfection. This study evaluated UV irradiated oocysts by three assays: a SCID mouse bioassay, an in vitro T. gondii oocyst plaque assay (TOP-assay), and a quantitative reve...

  20. Non-lethal infection parameters in mice separate sheep Type II Toxoplasma gondii isolates by virulence

    DEFF Research Database (Denmark)

    Jungersen, Gregers; Jensen, L; Rask, M.R.

    2002-01-01

    The zoonotic protozoan parasite Toxoplasma gondii can infect all warm-blooded animals, but virulence of isolates has previously been characterised mainly by the ability to kill mice after experimental infections. In the present study, 15 Type II strains of T. gondii, isolated from five adult sheep...

  1. Seroprevalence of Toxoplasma gondii infection in domestic pigs reared under different management in systems in Zimbabwe

    DEFF Research Database (Denmark)

    Hove, T.; Lind, Peter; Mukaratirwa, S.

    2005-01-01

    Serum samples from 474 domestic pigs (Sus scrola) from Zimbabwe were tested for anti-Toxoplasma gondii IgG antibodies using the indirect fluorescent antibody test. The results showed that T gondii infection is widespread in Zimbabwean pigs. Seroprevalence was lowest in fattening pigs from large...

  2. High seroprevalence of toxoplasma gondii in Elk (Cervus canadensis) of the Central Appalachians, USA

    Science.gov (United States)

    Toxoplasma gondii is an important protozoan parasite of mammals that impacts animal health and behavior. Although this parasite has been documented in several cervid species, including red deer (Cervus elaphus) in Europe, little is known about T. gondii impacts on the closely related North American ...

  3. Serological and parsitological prevalence of Toxoplasma gondii in wild birds from Colorado

    Science.gov (United States)

    Ground feeding birds are considered important in the epidemiology of Toxoplasma gondii because they serve as indicators of soil contamination by oocysts and birds of prey are indicators of T. gondii prevalence in rodents and other small mammals. Cats excrete environmentally resistant oocysts after c...

  4. Toxoplasma gondii exposure and Parkinson's disease: a case–control study

    Science.gov (United States)

    Alvarado-Esquivel, Cosme; Méndez-Hernández, Edna Madai; Salas-Pacheco, José Manuel; Ruano-Calderón, Luis Ángel; Hernández-Tinoco, Jesús; Arias-Carrión, Oscar; Sánchez-Anguiano, Luis Francisco; Castellanos-Juárez, Francisco Xavier; Sandoval-Carrillo, Ada Agustina; Liesenfeld, Oliver; Ramos-Nevárez, Agar

    2017-01-01

    Objectives To determine the association between Toxoplasma gondii infection and Parkinson's disease and to investigate whether T. gondii seropositivity is associated with the general characteristics of patients with Parkinson's disease. Design Case–control study. Setting Cases and controls were enrolled in Durango City, Mexico. Participants 65 patients with Parkinson's disease and 195 age- and gender-matched control subjects without Parkinson's disease. Primary and secondary outcome measures Serum samples of participants were analysed for anti-T. gondii IgG and IgM antibodies by commercially available enzyme-linked immunoassays. Prevalence of T. gondii DNA was determined in seropositive subjects using PCR. The association between clinical data and infection was examined by bivariate analysis. Results Anti-T. gondii IgG antibodies were found in 6/65 cases (9.2%) and in 21/195 controls (10.8%) (OR 0.84; 95% CI 0.32 to 2.18; p=0.81). The frequency of high (>150 IU/mL) antibody levels was similar among cases and controls (p=0.34). None of the anti-T. gondii IgG positive cases and four of the anti-T. gondii IgG positive controls had anti-T. gondii IgM antibodies (p=0.54). The prevalence of T. gondii DNA was comparable in seropositive cases and controls (16.7% and 25%, respectively; p=1.0). Seroprevalence of T. gondii infection was associated with a young age onset of disease (p=0.03), high Unified Parkinson Disease Rating Scale scores (p=0.04) and depression (p=0.02). Seropositivity to T. gondii infection was lower in patients treated with pramipexole than in patients without this treatment (p=0.01). However, none of the associations remained significant after Bonferroni correction. Conclusions The results do not support an association between T. gondii infection and Parkinson's disease. However, T. gondii infection might have an influence on certain symptoms of Parkinson's disease. Further research to elucidate the role of T. gondii exposure on Parkinson's disease

  5. Western Australian marsupials are multiply infected with genetically diverse strains of Toxoplasma gondii.

    Directory of Open Access Journals (Sweden)

    Shuting Pan

    Full Text Available Five different organs from 16 asymptomatic free-ranging marsupial macropods (Macropus rufus, M. fuliginosus, and M. robustus from inland Western Australia were tested for infection with Toxoplasma gondii by multi-locus PCR-DNA sequencing. All macropods were infected with T. gondii, and 13 had parasite DNA in at least 2 organs. In total, 45 distinct T. gondii genotypes were detected. Fourteen of the 16 macropods were multiply infected with genetically distinct T. gondii genotypes that often partitioned between different organs. The presence of multiple T. gondii infections in macropods suggests that native mammals have the potential to promote regular cycles of sexual reproduction in the definitive felid host in this environment.

  6. The first detection of Toxoplasma gondii DNA in environmental fruits and vegetables samples.

    Science.gov (United States)

    Lass, A; Pietkiewicz, H; Szostakowska, B; Myjak, P

    2012-06-01

    Toxoplasma gondii infections are prevalent in humans and animals all over the world. The aim of the study was to estimate the occurrence of T. gondii oocysts in fruits and vegetables and determine the genotype of the parasites. A total number of 216 fruits and vegetables samples were taken from shops and home gardens located in the area of northern Poland. Oocysts were recovered with the flocculation method. Then, real-time polymerase chain reaction (PCR) targeting the B1 gene was used for specific T. gondii detection and quantification. Toxoplasma DNA was found in 21 samples. Genotyping at the SAG2 locus showed SAG2 type I and SAG2 type II. This is the first investigation describing T. gondii DNA identification in a large number of fruits and vegetables samples with rapid molecular detection methods. The results showed that fruits and vegetables contaminated with T. gondii may play a role in the prevalence of toxoplasmosis in Poland.

  7. A novel Toxoplasma gondii nuclear factor TgNF3 is a dynamic chromatin-associated component, modulator of nucleolar architecture and parasite virulence.

    Directory of Open Access Journals (Sweden)

    Alejandro Olguin-Lamas

    2011-03-01

    Full Text Available In Toxoplasma gondii, cis-acting elements present in promoter sequences of genes that are stage-specifically regulated have been described. However, the nuclear factors that bind to these cis-acting elements and regulate promoter activities have not been identified. In the present study, we performed affinity purification, followed by proteomic analysis, to identify nuclear factors that bind to a stage-specific promoter in T. gondii. This led to the identification of several nuclear factors in T. gondii including a novel factor, designated herein as TgNF3. The N-terminal domain of TgNF3 shares similarities with the N-terminus of yeast nuclear FK506-binding protein (FKBP, known as a histone chaperone regulating gene silencing. Using anti-TgNF3 antibodies, HA-FLAG and YFP-tagged TgNF3, we show that TgNF3 is predominantly a parasite nucleolar, chromatin-associated protein that binds specifically to T. gondii gene promoters in vivo. Genome-wide analysis using chromatin immunoprecipitation followed by high-throughput sequencing (ChIP-seq identified promoter occupancies by TgNF3. In addition, TgNF3 has a direct role in transcriptional control of genes involved in parasite metabolism, transcription and translation. The ectopic expression of TgNF3 in the tachyzoites revealed dynamic changes in the size of the nucleolus, leading to a severe attenuation of virulence in vivo. We demonstrate that TgNF3 physically interacts with H3, H4 and H2A/H2B assembled into bona fide core and nucleosome-associated histones. Furthermore, TgNF3 interacts specifically to histones in the context of stage-specific gene silencing of a promoter that lacks active epigenetic acetylated histone marks. In contrast to virulent tachyzoites, which express the majority of TgNF3 in the nucleolus, the protein is exclusively located in the cytoplasm of the avirulent bradyzoites. We propose a model where TgNF3 acts essentially to coordinate nucleolus and nuclear functions by modulating

  8. Insect-cell expression, crystallization and X-ray data collection of the bradyzoite-specific antigen BSR4 from Toxoplasma gondii

    International Nuclear Information System (INIS)

    Grujic, Ognjen; Grigg, Michael E.; Boulanger, Martin J.

    2008-01-01

    Preliminary X-ray diffraction studies of the bradyzoite-specific surface antigen BSR4 from T. gondii are described. Toxoplasma gondii is an important global pathogen that infects nearly one third of the world’s adult population. A family of developmentally expressed structurally related surface-glycoprotein adhesins (SRSs) mediate attachment to and are utilized for entry into host cells. The latent bradyzoite form of T. gondii persists for the life of the host and expresses a distinct family of SRS proteins, of which the bradyzoite-specific antigen BSR4 is a prototypical member. Structural studies of BSR4 were initiated by first recombinantly expressing BSR4 in insect cells, which was followed by crystallization and preliminary X-ray data collection to 1.95 Å resolution. Data processing showed that BSR4 crystallized with one molecule in the asymmetric unit of the P4 1 2 1 2 or P4 3 2 1 2 space group, with a solvent content of 60% and a corresponding Matthews coefficient of 2.98 Å 3 Da −1

  9. Insect-cell expression, crystallization and X-ray data collection of the bradyzoite-specific antigen BSR4 from Toxoplasma gondii

    Energy Technology Data Exchange (ETDEWEB)

    Grujic, Ognjen [Biochemistry and Microbiology, University of Victoria, PO Box 3055 STN CSC, Victoria, BC, V8W 3P6 (Canada); Grigg, Michael E. [Molecular Parasitology Unit, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 4 Center Drive, Bethesda, MD 20892 (United States); Boulanger, Martin J., E-mail: mboulang@uvic.ca [Biochemistry and Microbiology, University of Victoria, PO Box 3055 STN CSC, Victoria, BC, V8W 3P6 (Canada)

    2008-05-01

    Preliminary X-ray diffraction studies of the bradyzoite-specific surface antigen BSR4 from T. gondii are described. Toxoplasma gondii is an important global pathogen that infects nearly one third of the world’s adult population. A family of developmentally expressed structurally related surface-glycoprotein adhesins (SRSs) mediate attachment to and are utilized for entry into host cells. The latent bradyzoite form of T. gondii persists for the life of the host and expresses a distinct family of SRS proteins, of which the bradyzoite-specific antigen BSR4 is a prototypical member. Structural studies of BSR4 were initiated by first recombinantly expressing BSR4 in insect cells, which was followed by crystallization and preliminary X-ray data collection to 1.95 Å resolution. Data processing showed that BSR4 crystallized with one molecule in the asymmetric unit of the P4{sub 1}2{sub 1}2 or P4{sub 3}2{sub 1}2 space group, with a solvent content of 60% and a corresponding Matthews coefficient of 2.98 Å{sup 3} Da{sup −1}.

  10. Seroprevalence of Toxoplasma gondii infection and associated risk factors in Huicholes in Mexico.

    Science.gov (United States)

    Alvarado-Esquivel, Cosme; Pacheco-Vega, Sandy Janet; Hernández-Tinoco, Jesús; Sánchez-Anguiano, Luis Francisco; Berumen-Segovia, Luis Omar; Rodríguez-Acevedo, Francisco Javier Imard; Beristain-García, Isabel; Rábago-Sánchez, Elizabeth; Liesenfeld, Oliver; Campillo-Ruiz, Federico; Güereca-García, Oscar Alberto

    2014-07-01

    Very little is known about the seroepidemiology of Toxoplasma gondii infection in ethnic groups in Mexico. Huicholes are an indigenous ethnic group living in a remote mountainous region in Mexico. We sought to determine the prevalence of anti-Toxoplasma IgG and IgM antibodies in Huicholes; and to determine the association of Toxoplasma seropositivity with socio-demographic, behavioral, and clinical characteristics of Huicholes. We performed a cross sectional survey in Huicholes from September 2013 to January 2014. A convenience sampling method was used. We investigated the prevalence of anti-Toxoplasma IgG and IgM antibodies in 214 Huicholes using enzyme-linked immunoassays. A standardized questionnaire was used to obtain the characteristics of the Huicholes. Bivariate and multivariate analyses were used to assess the association of Toxoplasma exposure and Huicholes' characteristics. Of the 214 Huicholes studied (mean age: 37.98 ± 15.80 years), 71 (33.2%) were positive for anti-T. gondii IgG antibodies and 47 (66.2%) of them were also positive for anti-T. gondii IgM antibodies. Seroprevalence of T. gondii infection did not vary with age, sex, or occupation. However, seroprevalence of anti-T. gondii IgM antibodies was significantly higher in female than in male Huicholes. Multivariate analysis of socio-demographic and behavioral characteristics showed that T. gondii exposure was associated with consumption of turkey meat (OR = 2.28; 95% CI: 1.16-4.46; P = 0.01). In addition, seroprevalence of T. gondii infection was significantly higher in Huicholes suffering from dizziness and memory impairment than those without such clinical characteristics. Our results demonstrate serological evidence of T. gondii exposure among Huicholes which may be impacting their health. Results of this first study of T. gondii infection in Huicholes may be useful for the design of optimal preventive measures against infection with T. gondii.

  11. Toxoplasma gondii in Blood Donors: A Study in Boyer-Ahmad County, Southwest Iran

    Directory of Open Access Journals (Sweden)

    Abdolali Moshfe

    2018-01-01

    Full Text Available Toxoplasma gondii is an important foodborne protozoan that can be transmitted through infected blood containing tachyzoite form of the parasite. The current study aimed to evaluate the prevalence of T. gondii infection and related risk factors among healthy blood donors in Boyer-Ahmad County, southwest Iran. Blood samples were taken from 285 healthy blood donors who voluntarily agreed to participate in this study. Sera and buffy coat were isolated from the blood samples for serological and molecular evaluations. The sera were tested for anti-T. gondii antibodies (both IgG and IgM, using a commercial ELISA kit. The buffy coat of seropositive cases was evaluated for detection of T. gondii DNA by PCR. Moreover, a structured questionnaire, containing socioepidemiological data and possible risk factors, was filled out by each participant during sample collection. Anti-T. gondii antibodies were detected in sera of 48/285 (16.8% participants. Only two of the subjects (0.7% were seropositive for both IgG and IgM antibodies. T. gondii DNA was not detected in buffy coat of any of the seropositive cases. Risk factors such as contact with soil (OR, 9.7; 95% CI, 4.9–19.4 and consumption of semicooked meat (OR, 2.5; 95% CI, 1.2–5.03 were statistically associated with seropositivity to T. gondii. The seroprevalence rate of T. gondii antibodies in the blood donors of Boyer-Ahmad County was not high in comparison with other regions in Iran. In this study, consumption of undercooked meats, job, and contact with soil were independent risk factors associated with T. gondii infection, which can be considered as potential sources of T. gondii infection.

  12. Detection and survival of Toxoplasma gondii in milk and cheese from experimentally infected goats.

    Science.gov (United States)

    Dubey, J P; Verma, S K; Ferreira, L R; Oliveira, S; Cassinelli, A B; Ying, Y; Kwok, O C H; Tuo, W; Chiesa, O A; Jones, J L

    2014-10-01

    The consumption of unpasteurized goat cheese and goat's milk has been suggested as a risk factor for toxoplasmosis in humans. In the present study, detection and survival of Toxoplasma gondii in milk and cheese was studied by bioassay in mice (milk) and in cats (cheese). Eight goats were inoculated orally with 300 to 10,000 oocysts of T. gondii strain TgGoatUS26. Milk samples were collected daily up to 30 days postinoculation and bioassayed in mice and cats. For mouse bioassay, 50 ml of milk samples were centrifuged, and the sediment was inoculated subcutaneously into mice. Mice were tested for T. gondii infection by seroconversion and by the demonstration of parasites. By mouse bioassay, T. gondii was detected in milk from all eight goats. The T. gondii excretion in milk was intermittent. For cat bioassay, 400 ml (100 ml or more from each goat) of milk from four goats from 6 to 27 days postinoculation were pooled daily, and cheese was made using rennin. Ten grams of cheese was fed daily to four cats, and cat feces were examined for oocyst shedding. One cat fed cheese shed oocysts 7 to 11 days after consuming cheese. Attempts were made to detect T. gondii DNA in milk of four goats; T. gondii was detected by PCR more consistently, but there was no correlation between detection of viable T. gondii by bioassay in mice and T. gondii DNA by PCR. Results indicate that T. gondii can be excreted in goat's milk and can survive in fresh cheese made by cold-enzyme treatment. To prevent transmission to humans or animals, milk should not be consumed raw. Raw fresh goat cheese made by cold-enzyme treatment of unpasteurized milk also should not be consumed.

  13. Localisation of gluconeogenesis and tricarboxylic acid (TCA)-cycle enzymes and first functional analysis of the TCA cycle in Toxoplasma gondii.

    Science.gov (United States)

    Fleige, Tobias; Pfaff, Nils; Gross, Uwe; Bohne, Wolfgang

    2008-08-01

    The apicomplexan parasite Toxoplasma gondii displays some unusual localisations of carbohydrate converting enzymes, which is due to the presence of a vestigial, non-photosynthetic plastid, referred to as the apicoplast. It was recently demonstrated that the single pyruvate dehydrogenase complex (PDH) in T. gondii is exclusively localised inside the apicoplast but absent in the mitochondrion. This raises the question about expression, localisation and function of enzymes for the tricarboxylic acid (TCA)-cycle, which normally depends on PDH generated acetyl-CoA. Based on the expression and localisation of epitope-tagged fusion proteins, we show that all analysed TCA cycle enzymes are localised in the mitochondrion, including both isoforms of malate dehydrogenase. The absence of a cytosolic malate dehydrogenase suggests that a typical malate-aspartate shuttle for transfer of reduction equivalents is missing in T. gondii. We also localised various enzymes which catalyse the irreversible steps in gluconeogenesis to a cellular compartment and examined mRNA expression levels for gluconeogenesis and TCA cycle genes between tachyzoites and in vitro bradyzoites. In order to get functional information on the TCA cycle for the parasite energy metabolism, we created a conditional knock-out mutant for the succinyl-CoA synthetase. Disruption of the sixth step in the TCA cycle should leave the biosynthetic parts of the cycle intact, but prevent FADH2 production. The succinyl-CoA synthetase depletion mutant displayed a 30% reduction in growth rate, which could be restored by supplementation with 2 microM succinate in the tissue culture medium. The mitochondrial membrane potential in these parasites was found to be unaltered. The lack of a more severe phenotype suggests that a functional TCA cycle is not essential for T. gondii replication and for maintenance of the mitochondrial membrane potential.

  14. Firocoxib on aqueous humor prostaglandin E 2 levels for controlling experimentally-induced breakdown of blood-aqueous barrier in healthy and Toxoplasma gondii -seropositive cats

    Directory of Open Access Journals (Sweden)

    Deise Cristine Schroder

    2016-06-01

    Full Text Available ABSTRACT: This study aimed to evaluate the effects of firocoxib for controlling experimentally-induced breakdown of the blood-aqueous barrier in healthy and Toxoplasma gondii -seropositive cats. Thirty two cats with no ocular abnormalities were used. Groups (n=8/each were formed with healthy cats that received 5mg g-1 of oral firocoxib (FH or no treatment (CH on day 0; seropositive cats for anti -T. gondii specific immunoglobulin G (IgG were grouped (n=8/each and treated in a similar fashion (FT and CT. On day 1, cats of all groups received the same treatment protocol, and 1h later, aqueocentesis was performed under general anesthesia (M0. Following 1h, the same procedure was repeated (M1. Quantitation of aqueous humor total protein and prostaglandin E2 (PGE2 were determined. Aqueous samples of seropositive cats were tested for anti- T. gondii specific IgG. In M0, aqueous samples of CT showed a significantly higher concentration of PGE2 in comparison with other groups (P<0.05. In all groups, PGE2 concentration increased significantly from M0 to M1 (P=0.001. PGE2 values did not change significantly between groups in M1 (P=0.17. Anti- T. gondii specific IgG were reported only in samples of M1, and aqueous titers did not change significantly between FT and CT (P=0.11. Although we have observed that aqueous humor PGE2 levels were significantly higher in cats of CT group during M0, such increase was not able to break the blood-aqueous barrier and cause anterior uveitis. Firocoxib did not prevent intraocular inflammation after aqueocentesis, in healthy and toxoplasmosis-seropositive cats.

  15. Detection and genotyping of Toxoplasma gondii DNA in the blood and milk of naturally infected donkeys (Equus asinus).

    Science.gov (United States)

    Mancianti, Francesca; Nardoni, Simona; Papini, Roberto; Mugnaini, Linda; Martini, Mina; Altomonte, Iolanda; Salari, Federica; D'Ascenzi, Carlo; Dubey, Jitender P

    2014-04-03

    Toxoplasma gondii is a worldwide zoonotic protozoan. Consumption of raw milk from infected animals is considered a risk factor for acquiring toxoplasmosis in humans. Recently, donkey milk has been indicated for therapeutic and nutritional purposes and T. gondii infection is common in donkeys. The purpose of the present paper was to detect the presence of parasite DNA in milk of T. gondii positive donkeys. Antibodies to T. gondii were found in 11 out of 44 healthy lactating donkeys by IFAT. T. gondii DNA was detected by PCR in blood of 6 and milk of 3 seropositive jennies. Results of limited RFLP-PCR genotyping indicated the presence of T. gondii genotype II or III, commonly found in Europe. The occurrence of T. gondii DNA in milk suggests that the consumption of raw milk from seropositive donkeys could be a potential source of human infection.

  16. Molecular Cloning, Expression and Characterization of Plasmid Encoding Rhomboid 4 (ROM4 of Tachyzoite of Toxoplasma gondii RH Strain

    Directory of Open Access Journals (Sweden)

    Mohammad Taghi RAHIMI

    2017-12-01

    Full Text Available AbstractBackground: The objective of this study was to clone, express and characterize the gene encoding rhomboid 4 (ROM4 proteins, a vital gene in surface adhesion and host cell invasion process of tachyzoite of T. gondii in an appropriate expression vector and eukaryotic cell for production of recombinant protein.Methods: Toxoplasma RNA was isolated from tachyzoites (RH strain and complementary DNA was synthesized. Oligonucleotide primer pair was designed based on Toxoplasma ROM4 gene sequence with XhoI and EcoRI restriction sites at 5´ end of forward and reverse primers, respectively. ROM4 gene was amplified by PCR, cloned into pTG19-T vector and the recombinant plasmid was sequenced. The gene was subcloned into pcDNA3 plasmid and expressed in CHO cells as eukaryotic cell. SDS-PAGE and western blotting were performed for protein determination and verification.Results: Cloning of ROM4 gene in pTG19-T vector was confirmed by colony-PCR and enzymatic digestion. The results of enzymatic digestion and gene sequencing confirmed successful cloning and subcloning procedures. The nucleotide sequence of the cloned ROM4 gene showed 99% homology compared to the corresponding sequences of original gene. SDS-PAGE and western blotting analyses of the purified protein revealed a single band having expected size of 65 kDa.Conclusion: This eukaryotic expression system is an appropriate system for high-level recombinant protein production of ROM4 gene from T. gondii tachyzoites used as antigenic component for serological assay and vaccine development.

  17. Evaluation of immunity and protection induced in experimental models by soluble extract of Toxoplasma gondii tachyzoites irradiated by 60Co

    International Nuclear Information System (INIS)

    Costa, Andrea da

    2013-01-01

    Toxoplasmosis affects 1/3 of the human population and only a vaccine for veterinary use. Gamma radiation alters the proteins making them more immunogenic by oxidation and better antigen presentation in the absence of adjuvants. Radiate soluble extract of RH strain tachyzoites of T. gondii (AgTg), and evaluate its use as a vaccine in BALB/c. Doses below 500Gy not affected and destroyed 2000Gy doses above extract, whereas animals immunized with irradiated extract at 1000, 1500 and 2000Gy had more of specific IgG avidity , compared to native AgTg (p<0,05) . AgTg 1500GY the immunized animals had increased proliferation of splenocytes, phenotyped as CD3+CD4+, CD3+CD8+ and B-lymphocytes immunized animals compared to the native AgTg . Animals immunized by AgTg 1500GY after challenge with strain ME- 49 cystogenic showed lower number of brain cysts and greater survival after challenge with virulent RH. Ionizing radiation in extracts of T. gondii increases the immune response and immune memory in the absence of adjuvants. (author)

  18. Recombinant vaccines against T. gondii: comparison between homologous and heterologous vaccination protocols using two viral vectors expressing SAG1.

    Directory of Open Access Journals (Sweden)

    Érica Araújo Mendes

    Full Text Available The use of recombinant viral vectors expressing T. gondii antigens is a safe and efficient approach to induce immune response against the parasite and a valuable tool for vaccine development. We have previously protected mice from toxoplasmosis by immunizing the animals with an adenovirus expressing the protein SAG1 (AdSAG1 of T. gondii. We are now looking for ways to improve the vaccination strategy and enhance protection. One limitation of homologous vaccinations (sequential doses of the same vector is induction of anti-vector immune response that blocks cell transduction, restricts transgene expression and, consequently, compromises the overall outcome of vaccination. One way to avert the effects of anti-vector response is to use different viruses in prime and boost (heterologous vaccination. Bearing this in mind, we generated a modified Vaccinia Virus Ankara encoding SAG1 (MVASAG1, to be tested as boost agent after prime with AdSAG1. Although minor differences were observed in the magnitude of the anti-SAG1 immune response induced by each vaccination protocol, the heterologous immunization with AdSAG1 followed by MVASAG1 resulted in improved capacity to control brain cyst formation in a model of chronic toxoplasmosis in C57BL/6 mice.

  19. Complete protection against lethal Toxoplasma gondii infection in mice immunized with a plasmid encoding the SAG1 gene

    DEFF Research Database (Denmark)

    Nielsen, H V; Lauemøller, S L; Christiansen, L

    1999-01-01

    Infection with the protozoan parasite Toxoplasma gondii is transmitted to humans from infected animals by tissue cysts and oocysts excreted by cats. Immunization with inactivated parasites or recombinant proteins has at best shown partial protection. We constructed a plasmid expressing the SAG1...... surface antigen of T. gondii, p1tPASAG1, and showed that animals immunized with the plasmid produce anti-SAG1 antibodies which recognize the native SAG1. Mice immunized with p1tPASAG1 showed 80 to 100% protection against challenge with the non-cyst-producing, virulent RH isolate, compared to an 80...... gamma interferon production by CD8(+) T cells from p1tPASAG1-immunized mice was tested in an ELISPOT assay, and one new CTL epitope was identified. Adoptive transfer of CD8(+) T cells from p1tPASAG1-immunized to naïve mice showed partial protection. In conclusion, DNA vaccination with p1tPASAG1 gave...

  20. LILRB4 Decrease on uDCs Exacerbate Abnormal Pregnancy Outcomes Following Toxoplasma gondii Infection

    Directory of Open Access Journals (Sweden)

    Shaowei Zhan

    2018-03-01

    Full Text Available Toxoplasma gondii (T. gondii infection in early pregnancy can result in miscarriage, dead fetus, and other abnormalities. The LILRB4 is a central inhibitory receptor in uterine dendritic cells (uDCs that plays essential immune-regulatory roles at the maternal–fetal interface. In this study, T. gondii-infected human primary uDCs and T. gondii-infected LILRB4-/- pregnant mice were utilized. The immune mechanisms underlying the role of LILRB4 on uDCs were explored in the development of abnormal pregnancy outcomes following T. gondii infection in vitro and in vivo. Our results showed that the expression levels of LILRB4 on uDCs from normal pregnant mice were obviously higher than non-pregnant mice, and peaked in mid-gestation. The LILRB4 expression on uDC subsets, especially tolerogenic subsets, from mid-gestation was obviously down-regulated after T. gondii infection and LILRB4 decrease could further regulate the expression of functional molecules (CD80, CD86, and HLA-DR or MHC II on uDCs, contributing to abnormal pregnancy outcomes. Our results will shed light on the molecular immune mechanisms of uDCs in abnormal pregnancy outcomes by T. gondii infection.

  1. Neospora caninum and Toxoplasma gondii antibodies in red foxes (Vulpes vulpes) in the Czech Republic.

    Science.gov (United States)

    Bártová, Eva; Slezáková, Radka; Nágl, Ivan; Sedlák, Kamil

    2016-01-01

    Neospora caninum and Toxoplasma gondii are worldwide spread parasites, causing serious illnesses in sensitive animals; toxoplasmosis is also important zoonosis. Although neosporosis is not considered as a zoonosis, it leads to aborted births in cattle, as well as paresis and paralysis in dogs. The aim of this study was to discover the prevalence of N. caninum and T. gondii antibodies in red foxes (Vulpes vulpes) in the Czech Republic. Sera of 80 foxes from 8 regions of the Czech Republic were tested for antibodies to N. caninum and T. gondii by competitive enzyme linked immunosorbent assay (cELISA) and indirect ELISA. All samples were simultaneously tested by indirect fluorescent antibody test (IFAT) to detect both N. caninum and T. gondii antibodies. Antibodies to N. caninum were found by IFAT in 3 (3.8%) red foxes with titre 50 and in 2 (2.5%) red foxes with inhibition 42.7% and 30.2 %. Antibodies to T. gondii were found in all tested animals in both IFAT (titres 50-6400) and in ELISA (S/P ranging from 34%-133%). This is the first prevalence study of N. caninum and T. gondii antibodies in red foxes in the Czech Republic. The results obtained show that red foxes are exposed at different levels to both protozoan infections, and thus could play an important role in the transmission cycle of N. caninum and T. gondii in sylvatic cycle.

  2. Azithromycin is able to control Toxoplasma gondii infection in human villous explants

    Science.gov (United States)

    2014-01-01

    Background Although Toxoplasma gondii infection is normally asymptomatic, severe cases of toxoplasmosis may occur in immunosuppressed patients or congenitally infected newborns. When a fetal infection is established, the recommended treatment is a combination of pyrimethamine, sulfadiazine and folinic acid (PSA). The aim of the present study was to evaluate the efficacy of azithromycin to control T. gondii infection in human villous explants. Methods Cultures of third trimester human villous explants were infected with T. gondii and simultaneously treated with either PSA or azithromycin. Proliferation of T. gondii, as well as production of cytokines and hormones by chorionic villous explants, was analyzed. Results Treatment with either azithromycin or PSA was able to control T. gondii infection in villous explants. After azithromycin or PSA treatment, TNF-α, IL-17A or TGF-β1 levels secreted by infected villous explants did not present significant differences. However, PSA-treated villous explants had decreased levels of IL-10 and increased IL-12 levels, while treatment with azithromycin increased production of IL-6. Additionally, T. gondii-infected villous explants increased secretion of estradiol, progesterone and HCG + β, while treatments with azithromycin or PSA reduced secretion of these hormones concurrently with decrease of parasite load. Conclusions In conclusion, these results suggest that azithromycin may be defined as an effective alternative drug to control T. gondii infection at the fetal-maternal interface. PMID:24885122

  3. Seroprevalence of Toxoplasma gondii infection in chickens in Durango State, Mexico.

    Science.gov (United States)

    Alvarado-Esquivel, C; González-Salazar, A M; Alvarado-Esquivel, D; Ontiveros-Vázquez, F; Vitela-Corrales, J; Villena, I; Dubey, J P

    2012-04-01

    Little is known concerning the seroprevalence of Toxoplasma gondii infection in chickens (Gallus domesticus) in Mexico. Antibodies to T. gondii were determined in 519 chickens in Durango, Mexico using the modified agglutination test (MAT). Two groups (A, B) of chickens were sampled. Group A chickens (n  =  51) were raised in backyards in 7 municipalities in 3 geographical regions in Durango State. Group B chickens were raised in farms in the Mexican States of Sinaloa (n  =  289) and Nayarit (n  =  179) but slaughtered in 2 abattoirs in Durango City. Overall, antibodies to T. gondii were found in 36 (6.9%) of 519 chickens, with MAT titers of 1∶25 in 22, 1∶50 in 8, 1∶100 in 2, 1∶200 in 3, and 1∶400 in 1. Seroprevalence of T. gondii increased significantly with age and was significantly higher in Group A chickens than in Group B chickens. In Group A chickens, a 25.5% seroprevalence of T. gondii infection was found. Seropositive chickens were found in all 7 municipalities sampled. In Group B chickens, the seroprevalence of T. gondii infection was 4.9%. This is the first report of T. gondii infection in chickens in Durango State, Mexico.

  4. Toxoplasma gondii Type I, predominant genotype isolated from sheep in South of Iran

    Directory of Open Access Journals (Sweden)

    Belal Armand

    2017-04-01

    Full Text Available Aim: This study was performed to determine the genetic diversity of Toxoplasma gondii in sheep using nested-polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP in Southern Iran. Materials and Methods: The tissue samples of diaphragm and heart from 125 sheep were collected from the main slaughterhouses of Jahrom district in South of Fars province, Iran, between Aprils and June 2013. The DNA were extracted and analyzed by nested-PCR using specific primers for SAG2 and GRA6 loci. RFLP was used to classify strains into one of the three major lineages of T. gondii. Results: T. gondii Type I was predominant in this area. The data obtained from both loci demonstrated that the frequency of each genotype was 72% Type I, 2.4% Type III, 7.2% mixed Type I and II, 16.8% mixed Type I and III, 0.8% mixed Type II and III, and 0.8% mixed Type I, II and III. Conclusion: Although the previously published data indicated that Type II is the predominant T. gondii genotype in sheep in the other parts of the world, this study showed that genotype I is the dominant genotype of T. gondii in the southern Iran; however, other genotypes were detected. High diversity of T. gondii genotypes including mix genotypes in lambs is of importance for the public health. These studies depict a new mapping of T. gondii genotypes pattern which could be very helpful in toxoplasmosis control and prevention.

  5. Non-association between anti-Toxoplasma gondii antibodies and ABO blood group system

    Directory of Open Access Journals (Sweden)

    ACF Rodrigues

    2011-01-01

    Full Text Available Toxoplasma gondii infects humans through the gastrointestinal tract (GIT, which elicits humoral immune response with specific antibodies. The expression of the ABO blood group glycoconjugates also occurs in this same system and may influence the human susceptibility of infection by T. gondii. The aim of the present study was to investigate the association between ABO blood group phenotypes and the presence of anti-T. gondii antibodies. Data - including age, results of serology tests for T. gondii infection and ABO blood group phenotypes - were assembled from the medical records of 1,006 pregnant women attended in the Base Hospital of the Medical School of São José do Rio Preto, Brazil, between 2001 and 2004. The chi-square test was used to compare the results with the level of significance set at 5%. Of the studied cases, 64.1% (645/1006 and 35.9% (391/1006 presented respectively positive and negative serology tests for anti-T. gondii antibodies. The mean age of those who tested positive was higher than those with negative serology tests (p = 0.0004. The frequencies of ABO blood group phenotypes were similar in those with and without anti-T. gondii antibodies (p = 0.35. In conclusion, the ABO blood group system is not associated with the presence or absence of anti-T. gondii antibodies.

  6. Toxoplasma gondii and Neospora caninum in wild small mammals: Seroprevalence, DNA detection and genotyping.

    Science.gov (United States)

    Machačová, Tereza; Ajzenberg, Daniel; Žákovská, Alena; Sedlák, Kamil; Bártová, Eva

    2016-06-15

    Generally, rodents and other small mammals are considered as one of the sources of Toxoplasma gondii or Neospora caninum infection for cats and dogs as the definitive hosts of these two parasites, respectively. The aim of the study was to find out the prevalence of these two parasites in wild small mammals from the Czech Republic and to characterize T. gondii isolates by methods of molecular biology. A total of 621 wild small mammals were caught in the Czech Republic during years 2002-2014. Antibodies to T. gondii were detected by latex agglutination test in six (2.5%) of 240 small mammals (in two A. agrarius and four A. flavicollis). Antibodies to N. caninum were detected by commercially available competitive-inhibition enzyme-linked immunosorbent assay in one A. flavicolis (0.4%). Three of 427 (0.7%) liver samples were positive for T. gondii by PCR while negative for N. caninum. All embryo samples (n=102) were negative for both T. gondii and N. caninum. The three liver samples positive for T. gondii DNA (two from A. flavicollis and one from A. sylvaticus) were genotyped by 15 microsatellite markers and characterized as type II. To our knowledge, this is the first information about genetic characterization of T. gondii isolates in small mammals from Europe and the first detection of N. caninum antibodies in wild rodents from the Czech Republic. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Seroprevalence of Toxoplasma gondii infection in arthritis patients in eastern China.

    Science.gov (United States)

    Tian, Ai-Ling; Gu, Yuan-Lin; Zhou, Na; Cong, Wei; Li, Guang-Xing; Elsheikha, Hany M; Zhu, Xing-Quan

    2017-10-25

    There is accumulating evidence for an increased susceptibility to infection in patients with arthritis. We sought to understand the epidemiology of Toxoplasma gondii infection in arthritis patients in eastern China, given the paucity of data on the magnitude of T. gondii infection in these patients. Seroprevalence of T. gondii infection was assessed by enzyme-linked immunosorbent assay using a crude antigen of the parasite in 820 arthritic patients, and an equal number of healthy controls, from Qingdao and Weihai cities, eastern China. Sociodemographic, clinical and lifestyle information on the study participants were also obtained. The prevalence of anti-T. gondii IgG was significantly higher in arthritic patients (18.8%) compared with 12% in healthy controls (P arthritis had anti-T. gondii IgM antibodies - comparable with 10 control patients (1.5% vs 1.2%). Demographic factors did not significantly influence these seroprevalence frequencies. The highest T. gondii infection seropositivity rate was detected in patients with rheumatoid arthritis (24.8%), followed by reactive arthritis (23.8%), osteoarthritis (19%), infectious arthritis (18.4%) and gouty arthritis (14.8%). Seroprevalence rates of rheumatoid arthritis and reactive arthritis were significantly higher when compared with controls (P arthritis patients in China. Implications for better prevention and control of T. gondii infection in arthritis patients are discussed. This is an epidemiological survey, therefore trial registration was not required.

  8. Concentration and retention of Toxoplasma gondii surrogates from seawater by red abalone (Haliotis rufescens)

    Science.gov (United States)

    Schott, Kristen C; Krusor, Colin; Tinker, M. Tim; Moore, James G.; Conrad, Patricia A.; Shapiro, Karen

    2016-01-01

    Small marine snails and abalone have been identified as high- and low-risk prey items, respectively, for exposure of threatened southern sea otters to Toxoplasma gondii, a zoonotic parasite that can cause fatal encephalitis in animals and humans. While recent work has characterized snails as paratenic hosts for T. gondii, the ability of abalone to vector the parasite has not been evaluated. To further elucidate why abalone predation may be protective against T. gondii exposure, this study aimed to determine whether: (1) abalone are physiologically capable of acquiring T. gondii; and (2) abalone and snails differ in their ability to concentrate and retain the parasite. Abalone were exposed to T. gondii surrogate microspheres for 24 h, and fecal samples were examined for 2 weeks following exposure. Concentration of surrogates was 2–3 orders of magnitude greater in abalone feces than in the spiked seawater, and excretion of surrogates continued for 14 days post-exposure. These results indicate that, physiologically, abalone and snails can equally vector T. gondii as paratenic hosts. Reduced risk of T. gondii infection in abalone-specializing otters may therefore result from abalone's high nutritional value, which implies otters must consume fewer animals to meet their caloric needs.

  9. Chronic Toxoplasma gondii in Nurr1-null heterozygous mice exacerbates elevated open field activity.

    Directory of Open Access Journals (Sweden)

    Jeffrey B Eells

    Full Text Available Latent infection with Toxoplasma gondii is common in humans (approximately 30% of the global population and is a significant risk factor for schizophrenia. Since prevalence of T. gondii infection is far greater than prevalence of schizophrenia (0.5-1%, genetic risk factors are likely also necessary to contribute to schizophrenia. To test this concept in an animal model, Nurr1-null heterozygous (+/- mice and wild-type (+/+ mice were evaluate using an emergence test, activity in an open field and with a novel object, response to bobcat urine and prepulse inhibition of the acoustic startle response (PPI prior to and 6 weeks after infection with T. gondii. In the emergence test, T. gondii infection significantly decreased the amount of time spent in the cylinder. Toxoplasma gondii infection significantly elevated open field activity in both +/+ and +/- mice but this increase was significantly exacerbated in +/- mice. T. gondii infection reduced PPI in male +/- mice but this was not statistically significant. Aversion to bobcat urine was abolished by T. gondii infection in +/+ mice. In female +/- mice, aversion to bobcat urine remained after T. gondii infection while the male +/- mice showed no aversion to bobcat urine. Antibody titers of infected mice were a critical variable associated with changes in open field activity, such that an inverted U shaped relationship existed between antibody titers and the percent change in open field activity with a significant increase in activity at low and medium antibody titers but no effect at high antibody titers. These data demonstrate that the Nurr1 +/- genotype predisposes mice to T. gondii-induced alterations in behaviors that involve dopamine neurotransmission and are associated with symptoms of schizophrenia. We propose that these alterations in murine behavior were due to further exacerbation of the altered dopamine neurotransmission in Nurr1 +/- mice.

  10. Epidemiological aspects of Toxoplasma gondii infection in riverside communities in the Southern Brazilian Amazon.

    Science.gov (United States)

    Vitaliano, Sérgio Neto; de Mendonça, Gabriel Maciel; de Sandres, Felipe Amsterdam Maia; Camargo, Juliana de Souza Almeida Aranha; de Tarso, Paulo; Basano, Sérgio de Almeida; Silva, Jéssica Carolinne Damasceno E; de Souza, Viviane Krominski Graça; Cartonilho, Glenci; de Almeida, Alexandre Thomé da Silva; Gennari, Solange Maria; Camargo, Luís Marcelo Aranha

    2015-01-01

    Toxoplasma gondii infection is widely prevalent in humans and other animals worldwide. Information on the prevalence of T. gondii infection is scarce in some regions of Brazil, including riverside communities along the Amazon River basin. The prevalence of T. gondii in 231 people, aged 1-85 years, who were living in four riverside communities along the Purus River, Lábrea, State of Amazonas, Brazil, was determined. Antibodies against T. gondii were assayed using a commercial enzyme-linked immunosorbent assay (ELISA) kit. The hearts and brains of 50 chickens, which were raised free-range in the communities, were pooled according to the community of origin and bioassayed in mice. The isolates were genotyped using polymorphisms at 12 nuclear markers (SAG1, 5' and 3'-SAG2, alt.SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, Apico and CS3). The overall seroprevalence of T. gondii was 56.7% (131/231). IgG antibodies were presented by 117 (89.3%) and IgM by 14 (10.7%) of the 131 positive individuals. No association between age group and gender with prevalence was observed (chi-square test, p > 0.05); however, the comparison between localities showed that the seroprevalence of T. gondii was significantly lower among the individuals living in the Boca do Ituxi (p < 0.05) community. Five isolates of T. gondii were obtained in the mouse bioassay, and genotyping revealed two complete genotypes that had not been described previously and three mixed isolates. These results support previous findings that T. gondii population genetics are highly diverse in Brazil and that T. gondii infection is active in these riverside communities.

  11. Epidemiological aspects of Toxoplasma gondii infection in riverside communities in the Southern Brazilian Amazon

    Directory of Open Access Journals (Sweden)

    Sérgio Neto Vitaliano

    2015-06-01

    Full Text Available INTRODUCTION: Toxoplasma gondii infection is widely prevalent in humans and other animals worldwide. Information on the prevalence of T. gondii infection is scarce in some regions of Brazil, including riverside communities along the Amazon River basin. M METHODS: The prevalence of T. gondii in 231 people, aged 1-85 years, who were living in four riverside communities along the Purus River, Lábrea, State of Amazonas, Brazil, was determined. Antibodies against T. gondii were assayed using a commercial enzyme-linked immunosorbent assay (ELISA kit. The hearts and brains of 50 chickens, which were raised free-range in the communities, were pooled according to the community of origin and bioassayed in mice. The isolates were genotyped using polymorphisms at 12 nuclear markers (SAG1, 5' and 3'-SAG2, alt.SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, Apico and CS3. RESULTS: The overall seroprevalence of T. gondii was 56.7% (131/231. IgG antibodies were presented by 117 (89.3% and IgM by 14 (10.7% of the 131 positive individuals. No association between age group and gender with prevalence was observed (chi-square test, p > 0.05; however, the comparison between localities showed that the seroprevalence of T. gondii was significantly lower among the individuals living in the Boca do Ituxi (p < 0.05 community. Five isolates of T. gondii were obtained in the mouse bioassay, and genotyping revealed two complete genotypes that had not been described previously and three mixed isolates. CONCLUSIONS: These results support previous findings that T. gondii population genetics are highly diverse in Brazil and that T. gondii infection is active in these riverside communities.

  12. Toxoplasma gondii Infection in Seagull Chicks Is Related to the Consumption of Freshwater Food Resources.

    Directory of Open Access Journals (Sweden)

    Oscar Cabezón

    Full Text Available Understanding the spread of Toxoplasma gondii (T. gondii in wild birds, particularly in those with opportunistic feeding behavior, is of interest for elucidating the epidemiological involvement of these birds in the maintenance and dissemination of the parasite. Overall, from 2009 to 2011, we collected sera from 525 seagull chicks (Yellow-legged gull (Larus michahellis and Audouin's gull (L. audouinii from 6 breeding colonies in Spain and tested them using the modified agglutination test (MAT for the presence of antibodies against T. gondii. Chick age was estimated from bill length. Main food source of seagull chicks was evaluated using stable isotope analyses from growing scapular feathers. Overall T. gondii seroprevalence was 21.0% (IC95% 17.5-24.4. A generalized linear mixed-effects model indicated that year (2009 and food source (freshwater were risk factors associated to the individual risk of infection by T. gondii, while age (days was close to significance. Freshwater food origin was related to the highest seroprevalence levels, followed by marine origin, supporting freshwater and sewages as important routes of dispersion of T. gondii. Year differences could indicate fluctuating rates of exposure of seagull chicks to T. gondii. Age ranged from 4 to 30 days and seropositivity tended to increase with age (P = 0.07, supporting that seropositivity is related to T. gondii infection rather than to maternal transfer of antibodies, which in gulls is known to sharply decrease with chick age. This study is the first to report T. gondii antibodies in Yellow-legged and Audouin's gulls, thereby extending the range of intermediate hosts for this parasite and underscoring the complexity of its epidemiology.

  13. Toxoplasmosis and genotyping of Toxoplasma gondii in Macropus rufus and Macropus giganteus in Argentina.

    Science.gov (United States)

    Moré, G; Pardini, L; Basso, W; Machuca, M; Bacigalupe, D; Villanueva, M C; Schares, G; Venturini, M C; Venturini, L

    2010-04-19

    Toxoplasma gondii infection is frequently asymptomatic; however, it can be severe or even fatal to some hosts. In this study, diagnosis of disseminated toxoplasmosis in one red kangaroo (Macropus rufus) and one great grey kangaroo (Macropus giganteus) from the La Plata Zoo, Argentina and the isolation and molecular characterization of T. gondii are reported. Both male kangaroos showed depression and sudden death. Toxoplasma gondii infection was diagnosed by fresh examination, histopathology, immunohistochemistry, PCR and bioassay in mice. During fresh examination many protozoan cysts were observed in diaphragm, heart and hind limb muscles of M. rufus. Cysts were also observed in samples from M. giganteus, although in lower number. Cysts from both kangaroos stained strongly with T. gondii anti-serum by immunohistochemistry. The M. rufus showed more considerable histopathological lesions like non-suppurative meningoencephalitis, myositis and myocarditis. All mice inoculated with tissues from both kangaroos developed IFAT titers to T. gondii (titer >or=800) and brain cysts at necropsy. Both T. gondii isolates were maintained by mice passages and the M. rufus isolate was also maintained in cell culture. Toxoplasma gondii DNA from tissue samples was analyzed by PCR-RFLP analysis using the markers 5'SAG2, 3'SAG2, BTUB, GRA6, SAG3, c22-8, L358, PK1, c29-2 and Apico. Genotyping revealed that the T. gondii isolate from M. rufus was clonal type III and the isolate from M. giganteus was clonal type II. This is the first report of disseminated toxoplasmosis in M. rufus and M. giganteus in Argentina caused by genotypes of T. gondii considered non-virulent in a mouse model.

  14. Antiretroviral activity of protease inhibitors against Toxoplasma gondii

    Directory of Open Access Journals (Sweden)

    Lianet Monzote

    2013-02-01

    Full Text Available The introduction of highly active antiretroviral therapy (HAART has caused a marked reduction in the occurrence and severity of parasitic infections, including the toxoplasmic encephalitis (TE. These changes have been attributed to the restoration of cell-mediated immunity. This study was developed to examine the activity of six antiretroviral protease inhibitors (API on Toxoplasma gondii tachyzoites. The six API showed anti-Toxoplasma activity, with IC50 value between 1.4 and 6.6 µg/mL. Further studies at the molecular level should be performed to clarify if the use of API could be beneficial or not for AIDS patients with TE.

  15. Latent Toxoplasma gondii Infection and Associated Risk Factors among HIV-Infected Individuals at Arba Minch Hospital, South Ethiopia

    Directory of Open Access Journals (Sweden)

    Tsegaye Yohanes

    2014-01-01

    Full Text Available Toxoplasmosis is a parasitic disease caused by Toxoplasma gondii (T. gondii. The parasite has cosmopolitan distribution, infecting almost all species of warm-blooded animals. Latent T. gondii infection in HIV/AIDS patients is a risk for development of cerebral toxoplasmosis (CT. The aim of this study is to determine seroprevalence of latent T. gondii infection and assess its associated factors among individuals infected with HIV in Arba Minch Hospital, south Ethiopia. A facility-based cross-sectional study involving 170 HIV-infected individuals attending Arba Minch Hospital antiretroviral therapy (ART clinic was conducted from April to June 2013. Data on demographic profile of the study participants and factors associated with T. gondii infection were gathered using a questionnaire. Serum was tested for IgG anti-T. gondii antibody by enzyme-linked immunosorbent assay (ELISA. Data were analyzed using SPSS version 20 software. Seroprevalence of latent T. gondii infection among the study participants was 88.2%. Consumption of raw meat (AOR = 4.361; 95% CI: 1.409–13.496 and involvement in farming/gardening activities (AOR = 4.051; 95% CI: 1.112–14.758 were independent predictors of T. gondii seropositivity. This study revealed high prevalence of latent T. gondii infection, similar to other studies. Monitoring of the patients to prevent reactivation of the latent T. gondii infection is recommended.

  16. Toxoplasma gondii Infection and Premenstrual Dysphoric Disorder: A Cross-Sectional Study

    Science.gov (United States)

    Alvarado-Esquivel, Cosme; Sanchez-Anguiano, Luis Francisco; Hernandez-Tinoco, Jesus; Perez-Alamos, Alma Rosa; Rico-Almochantaf, Yazmin del Rosario; Estrada-Martinez, Sergio; Vaquera-Enriquez, Raquel; Diaz-Herrera, Arturo; Ramos-Nevarez, Agar; Sandoval-Carrillo, Ada Agustina; Salas-Pacheco, Jose Manuel; Cerrillo-Soto, Sandra Margarita; Antuna-Salcido, Elizabeth Irasema; Liesenfeld, Oliver; Guido-Arreola, Carlos Alberto

    2016-01-01

    Background Premenstrual dysphoric disorder is a severe form of premenstrual syndrome. The influence of Toxoplasma gondii (T. gondii) infection on clinical features in women with this disorder has not been studied. Therefore, we determined the association of T. gondii infection with symptoms and signs in women suffering from premenstrual dysphoric disorder. Methods We performed a cross-sectional study of 151 women suffering from premenstrual dysphoric disorder. Anti-Toxoplasma IgG and IgM antibodies were detected in sera of the participants using enzyme-linked immunoassays (EIAs). In addition, T. gondii DNA was detected in whole blood of IgG seropositive participants using polymerase chain reaction. We obtained the clinical data of women with the aid of a questionnaire. The association of T. gondii infection with clinical characteristics of women was assessed by bivariate and multivariate analyses. Results Anti-T. gondii IgG antibodies were found in 10 (6.6%) of the 151 women studied. Of the 10 IgG seropositive women, four (40.0%) were positive for anti-T. gondii IgM antibodies, and one (10.0%) for T. gondii DNA. Mean number (25.8 ± 7.58) of premenstrual clinical characteristics in seropositive women was similar to that (29.22 ± 9.13) found in seronegative women (P = 0.25). Logistic regression showed that seropositivity to T. gondii was negatively associated with difficulty concentrating (OR: 0.18; 95% CI: 0.03 - 0.91; P = 0.03), and positively associated with out of control feeling or overwhelmed (OR: 9.00; 95% CI: 1.32 - 62.00; P = 0.02). Conclusions Results of this first study on the association of T. gondii infection and clinical characteristics of premenstrual dysphoric disorder suggest that this infection might be linked to some symptoms of this disorder. We report for the first time the association of T. gondii infection and out of control feeling or overwhelmed. Results warrant for further research on the role of T. gondii in premenstrual dysphoric

  17. Seroepidemiology of infection with Toxoplasma gondii in healthy blood donors of Durango, Mexico

    Directory of Open Access Journals (Sweden)

    Estrada-Martínez Sergio

    2007-07-01

    Full Text Available Abstract Background Toxoplasma gondii (T. gondii infection in blood donors could represent a risk for transmission in blood recipients. There is scarce information about the epidemiology of T. gondii infection in blood donors in Mexico. Therefore, we sought to determine the prevalence of T. gondii infection and associated socio-demographic and behavioral characteristics in a population of healthy blood donors of Durango City, Mexico. Methods Four hundred and thirty two blood donors in two public blood banks of Durango City, Mexico were examined for T. gondii infection between August to September 2006. Blood donors were tested for anti-T. gondii IgG and IgM antibodies by using enzyme-linked immunoassays (Diagnostic Automation Inc., Calabasas, CA, USA. Socio-demographic and behavioral characteristics from each participant were also obtained. Results Thirty two (7.4% of 432 blood donors had IgG anti-T. gondii antibodies. Eight (1.9% of them had also IgM anti-T. gondii antibodies. Multivariate analysis using logic regression showed that T. gondii infection was associated with the presence of cats at home (adjusted OR = 3.81; 95% CI: 1.45–10.01. The age group of 45–60 years showed a significantly higher frequency of T. gondii infection than the group of 25–34 years (p = 0.02. Blood donors without education had a significantly higher frequency of infection (15.8% than those with 13–19 years of education (4.5% (p = 0.04. Other characteristics of blood donors including male gender, consumption of undercooked meat or blood transfusion did not show an association with infection. Conclusion The prevalence of T. gondii infection in healthy blood donors of Durango City, Mexico is lower than those reported in blood donors of south and central Mexico, and is one of the lowest reported in blood donors worldwide. T. gondii infection in our blood donors was most likely acquired by contact with cats. Prevalence of infection increased with age and decreased

  18. Seroprevalence of Toxoplasma gondii in Danish farmed mink (Mustela vison S.)

    DEFF Research Database (Denmark)

    Henriksen, P; Dietz, H. H.; Uttenthal, Åse

    1994-01-01

    One hundred and ninety-five mink sera randomly selected from 17 Danish mink farms were evaluated for the presence of Toxoplasma gondii antibodies in the latex agglutination test. Six (3%) sera contained T. gondii antibodies in titres of 1:64 or more. The estimated 3% prevalence means that 300 000...... mink out of a total mink population of ten million might be infected with Toxoplasma gondii. This large number of possible sero-positive mink in Denmark indicates that there exists a potential risk of acquiring toxoplasmosis by pelting mink....

  19. Serosurvey of Leptospira spp. and Toxoplasma gondii in rats captured from two zoos in Southern Brazil.

    Science.gov (United States)

    Pellizzaro, Maysa; Conrado, Francisco de Oliveira; Martins, Camila Marinelli; Joaquim, Sâmea Fernandes; Ferreira, Fernando; Langoni, Helio; Biondo, Alexander Welker

    2017-01-01

    Norway rats (Rattus norvegicus) are zoonotic reservoirs for Leptospira spp. and Toxoplasma gondii, and influence diseases in urban areas. Free-ranging and laboratory-raised rats from two zoos in southern Brazil were tested for Leptospira spp. and T. gondii using microscopic agglutination and modified agglutination tests, respectively. Overall, 25.6% and 4.6% free-ranging rats tested positive for Leptospira spp. and T. gondii, respectively, with co-seropositivity occurring in two animals. For laboratory-raised rats, 20% tested positive for Leptospira spp. Also, Leptospira biflexa serovar Patoc and Leptospira noguchii serovar Panama were found. Serosurveys can show the environmental prevalence of zoonotic pathogens.

  20. Rottlerin-mediated inhibition of Toxoplasma gondii growth in BeWo trophoblast-like cells.

    Science.gov (United States)

    Ietta, Francesca; Maioli, Emanuela; Daveri, Elena; Gonzaga Oliveira, Juliana; da Silva, Rafaela José; Romagnoli, Roberta; Cresti, Laura; Maria Avanzati, Anna; Paulesu, Luana; Barbosa, Bellisa de Freitas; Gomes, Angelica de Oliveira; Roberto Mineo, José; Ferro, Eloisa Amália Vieira

    2017-04-28

    Autophagy is a crucial and physiological process for cell survival from yeast to mammals, including protozoan parasites. Toxoplasma gondii, an intracellular parasite, typically exploits autophagic machinery of host cell; however host cell upregulates autophagy to combat the infection. Herein we tested the efficacy of Rottlerin, a natural polyphenol with autophagic promoting properties, against Toxoplasma infection on the chorioncarcinoma-derived cell line BeWo. We found that Rottlerin, at sub-toxic doses, induced morphological and biochemical alterations associated with autophagy and decreased Toxoplasma growth in infected cells. Although autophagy was synergically promoted by Toxoplasma infection in combination with Rottlerin treatment, the use of the autophagy inhibitor chloroquine revealed that Rottlerin anti-parasitic effect was largely autophagy-independent and likely mediated by the converging inhibitory effect of Rottlerin and Toxoplasma in host protein translation, mediated by mTOR inhibition and eIF2α phosphorylation. Both events, which on one hand could explain the additive effect on autophagy induction, on the other hand led to inhibition of protein synthesis, thereby depriving Toxoplasma of metabolically essential components for multiplication. We suggest that modulation of the competition between pathogen requirement and host cell defense might be an attractive, novel therapeutic approach against Toxoplasma infection and encourage the development of Rottlerin-based new therapeutic formulations.

  1. Impaired Chromatin Remodelling at STAT1-Regulated Promoters Leads to Global Unresponsiveness of Toxoplasma gondii-Infected Macrophages to IFN-γ

    Science.gov (United States)

    Lang, Christine; Hildebrandt, Anke; Brand, Franziska; Opitz, Lennart; Dihazi, Hassan; Lüder, Carsten G. K.

    2012-01-01

    Intracellular pathogens including the apicomplexan and opportunistic parasite Toxoplasma gondii profoundly modify their host cells in order to establish infection. We have shown previously that intracellular T. gondii inhibit up-regulation of regulatory and effector functions in murine macrophages (MΦ) stimulated with interferon (IFN)-γ, which is the cytokine crucial for controlling the parasites' replication. Using genome-wide transcriptome analysis we show herein that infection with T. gondii leads to global unresponsiveness of murine macrophages to IFN-γ. More than 61% and 89% of the transcripts, which were induced or repressed by IFN-γ in non-infected MΦ, respectively, were not altered after stimulation of T. gondii-infected cells with IFN-γ. These genes are involved in a variety of biological processes, which are mostly but not exclusively related to immune responses. Analyses of the underlying mechanisms revealed that IFN-γ-triggered nuclear translocation of STAT1 still occurred in Toxoplasma-infected MΦ. However, STAT1 bound aberrantly to oligonucleotides containing the IFN-γ-responsive gamma-activated site (GAS) consensus sequence. Conversely, IFN-γ did not induce formation of active GAS-STAT1 complexes in nuclear extracts from infected MΦ. Mass spectrometry of protein complexes bound to GAS oligonucleotides showed that T. gondii-infected MΦ are unable to recruit non-muscle actin to IFN-γ-responsive DNA sequences, which appeared to be independent of stimulation with IFN-γ and of STAT1 binding. IFN-γ-induced recruitment of BRG-1 and acetylation of core histones at the IFN-γ-regulated CIITA promoter IV, but not β-actin was diminished by >90% in Toxoplasma-infected MΦ as compared to non-infected control cells. Remarkably, treatment with histone deacetylase inhibitors restored the ability of infected macrophages to express the IFN-γ regulated genes H2-A/E and CIITA. Taken together, these results indicate that Toxoplasma-infected MΦ are

  2. Immunosuppression with cyclophosphamide favors reinfection with recombinant Toxoplasma gondii strains

    Directory of Open Access Journals (Sweden)

    Silva L.A.

    2012-08-01

    Full Text Available The aim of this study was to verify the effect of immunosuppression by cyclophosphamide (Cy on susceptibility of BALB/c mice subjected to challenge with recombinant strains of Toxoplasma gondii. Animals were prime infected with the D8 (recombinant I/III or the ME49 (type II non-virulent strains, weekly immunosuppressed with Cy and challenged with the CH3 or EGS virulent strains (I/III. Parasites recovered from surviving mice were submitted to PCR-RFLP analysis to confirm co-infection. Prime-infection with the D8 strain conferred more protection against challenge with the CH3 and EGS strains when compared with ME49 prime infection. Cy treatment caused significant leukopenia in the infected mice, what probably favors reinfection after challenge. Reinfection was associated with increased levels of IgA. Otherwise, Cy-treated mice presented significantly lower IgA levels after challenge, suggesting involvement of this immunoglobulin on protection against reinfection. In conclusion, BALB/c mice susceptibility to reinfection by T. gondii is related to genetic differences among the strains used for primary and challenge infections. Alteration of the host’s immune integrity by Cy probably compromises the protection previously established by primary infection.

  3. Serologic, molecular, and pathologic survey of Toxoplasma gondii infection in free-ranging red foxes (Vulpes vulpes) in central Italy.

    Science.gov (United States)

    Verin, Ranieri; Mugnaini, Linda; Nardoni, Simona; Papini, Roberto Amerigo; Ariti, Gaetano; Poli, Alessandro; Mancianti, Francesca

    2013-07-01

    We tested 191 sera of red foxes (Vulpes vulpes; 78 females and 113 males) for antibodies to Toxoplasma gondii using an indirect immunofluorescent test. Tissue samples of myocardium, lymph nodes, and brains from antibody-positive animals were tested for T. gondii DNA using specific PCR and processed for histopathology and immunohistochemistry (IHC) to detect T. gondii antigen. Of 192 (53.4%) antibody-positive animals, eight were positive by PCR on myocardium and one on brain. All DNA extracts were genotyped. Histopathology showed lesions characteristic of protozoan encephalitis; IHC did not show T. gondii antigen in examined tissues. The high antibody prevalence found in our study, which is the first in Italy, and the occurrence of polymorphic strains (combination of different type I and III alleles) divergent from typical T. gondii strains, suggests red foxes may be a sentinel of T. gondii in the environment.

  4. DETECTION OF INFECTION WITH Toxoplasma gondii IN MANATEES (Trichechus inunguis OF THE PERUVIAN AMAZON

    Directory of Open Access Journals (Sweden)

    Patrick Mathews Delgado

    2013-01-01

    Full Text Available The Amazonian manatee (Trichechus inunguis is an aquatic mammal that inhabits freshwater environments and is endemic to the Amazon Basin. The presence of Toxoplasma gondii antibodies was investigated in 19 manatees in one rescue unit in the northern region of Peru. Antibodies to T. gondii were detected in 12 (63.2 % of 19 animals by using the modified agglutination test (titer, 1:25, and no association between sex and age of the animals and the presence of T. gondii antibodies was observed (p < 0.05. The results suggest a contamination by T. gondii oocysts in the aquatic environment where these animals live.

  5. Seroprevalence of Toxoplasma gondii from free-ranging black bears ( Ursus americanus ) from Florida.

    Science.gov (United States)

    Chambers, D L; Ulrey, W A; Guthrie, J M; Kwok, O C H; Cox, J J; Maehr, D S; Dubey, J P

    2012-06-01

    Toxoplasma gondii is a significant worldwide parasitic protozoan. In the present study, prevalence of antibodies of T. gondii was examined from 29 free-ranging black bears ( Ursus americanus ) from south-central Florida where the host species was listed as state threatened during this project. Overall T. gondii prevalence was found to be 44.8%, specifically 46.2% in male and 43.8% in female U. americanus , using a modified agglutination test (1:25 titer). Seroprevalence differences between sexes were not significant (P > 0.05). Results of the present study add supportive data to the growing body of evidence suggesting that U. americanus has one of the highest T. gondii seroprevalences among all known intermediate hosts. In addition, our data emphasize the importance of understanding parasitic disease dynamics from a conservation perspective.

  6. Seroprevalence and factors associated with Toxoplasma gondii infection in domestic cats from urban areas in Latvia.

    Science.gov (United States)

    Deksne, Gunita; Petrusēviča, Agnese; Kirjušina, Muza

    2013-02-01

    Felids are important in the epidemiology of Toxoplasma gondii infection because they are the only hosts that shed resistant oocysts in the environment. A total of 242 serum samples and 80 fecal samples from domestic cats in Latvia was tested for T. gondii infection. Serum samples were tested for T. gondii antibodies by an indirect in-house ELISA; antibodies were found in 125 (51.6%) of 242 cats; seroprevalence increased with age, indicating postnatal infection. Using multiple logistic regression analyses, age and outdoor access were found to be the most significant (F = 21.70, P Latvia. Toxoplasma gondii -like oocysts were detected in 2 of the cats examined microscopically using the salt flotation method, but definitive diagnosis could not be made because a bioassay was not performed.

  7. First molecular evidence of Toxoplasma gondii in opossums (Didelphis virginiana from Yucatan, Mexico

    Directory of Open Access Journals (Sweden)

    M. Torres-Castro

    2016-03-01

    Full Text Available Toxoplasma gondii is an obligate intracellular parasite recognized as a causal agent of toxoplasmosis; zoonotic disease endemic in many countries worldwide, including Mexico. Different species of animals participate in the wild cycle infection, including opossums of the species Didelphis virginiana. Thirteen D. virginiana were captured in Yucatan, Mexico. Detection of T. gondii was achieved by Polymerase Chain Reaction, which determined an infection of 76.9% (10/13 in brains. Positive amplicons were sequenced for analysis, this produced results similar to T. gondii with identity and coverage values of 98% and 96-100%, respectively. This study presents the first molecular evidence of the circulation of T. gondii in D. virginiana from Mexico.

  8. First molecular evidence of Toxoplasma gondii in opossums (Didelphis virginiana) from Yucatan, Mexico.

    Science.gov (United States)

    Torres-Castro, M; Noh-Pech, H; Puerto-Hernández, R; Reyes-Hernández, B; Panti-May, A; Hernández-Betancourt, S; Yeh-Gorocica, A; González-Herrera, L; Zavala-Castro, J; Puerto, F I

    2016-01-01

    Toxoplasma gondii is an obligate intracellular parasite recognized as a causal agent of toxoplasmosis; zoonotic disease endemic in many countries worldwide, including Mexico. Different species of animals participate in the wild cycle infection, including opossums of the species Didelphis virginiana. Thirteen D. virginiana were captured in Yucatan, Mexico. Detection of T. gondii was achieved by Polymerase Chain Reaction, which determined an infection of 76.9% (10/13) in brains. Positive amplicons were sequenced for analysis, this produced results similar to T. gondii with identity and coverage values of 98% and 96-100%, respectively. This study presents the first molecular evidence of the circulation of T. gondii in D. virginiana from Mexico.

  9. Seroprevalence of Toxoplasma gondii infection in Liaoning cashmere goat from northeastern China

    Directory of Open Access Journals (Sweden)

    Xu Peng

    2014-01-01

    Full Text Available In the present study, serum samples from 650 goats were collected from five counties between May and June 2012 and antibodies to Toxoplasma gondii were detected by indirect haemagglutination assay; 58 (9% had antibodies to T. gondii with antibody titres of 1:64 to 1:1024. Seropositive samples were distributed in all five counties: seroprevalences in Kuandian county (15%, 21/139, 95% confidence interval [CI] 9–21% were statistically different from the four other counties (Gaizhou, Huanren, Xiuyan and Liaoyang, and the seroprevalence difference between Xiuyan county (12%, 15/127, 95% CI 6–17% and two other counties (Huanren, Liaoyang was significantly different (P < 0.05. To our knowledge, this is the first report of the seroprevalence of T. gondii exposure in Liaoning cashmere goat in China. Our results indicated that Liaoning cashmere goat could be a potential reservoir for the transmission of T. gondii in Liaoning Province.

  10. Infection rate of toxoplasma gondii and age distribution in female patients with sterility

    International Nuclear Information System (INIS)

    Li Shuhong; Dai Pei; Cui Liming; Zong Shan; Zuo Wenjing

    2006-01-01

    Objective: To discuss the relationship between the infection of Toxoplasma gondii and female sterility. Methods: Toxoplasma gondii serum antibody were determined in 882 women with sterility (experimental group) and 107 normal bearing women (control group) by using ELISA. At the same time the differences of the infection with Toxoplasma gondii between the ages of the sterility women were analyzed. Results: The positive rate in experimental group was 15.87% (140/882), the positive rate in control group was 5.61% (6/107), remarkable difference was found between two groups (P<0.01). The infection rate in the different age groups (20-24, 25-29, 30-34, 35-39 and ≥40) is 5.63%, 15.24%, 17.91%, 19.44% and 15.38%. Conclusion: Toxoplasma gondii infection may be one of the factors which can cause sterility, and the infection rates at different ages have no instinct differences. (authors)

  11. Literature Reference for Toxoplasma gondii (Applied and Environmental Microbiology. 2004. 70(7): 4035–4039)

    Science.gov (United States)

    Procedures are described for analysis of water samples and may be adapted for assessment of solid, particulate and liquid samples. The method uses real-time PCR assay for detecting Toxoplasma gondii DNA using gene-specific primers and probe.

  12. Detection of toxoplasma gondii antigens in sera from experimentally infected mice

    International Nuclear Information System (INIS)

    Shojaee, S.; Keshavarz, H.; Rezaian, M.; Mohebali, M.

    2007-01-01

    Detection of Toxoplasma antigen in serum of mice by Immunoblotting. strain. IgG isolated from rabbits that were immunized with T. gondii Immunoblotting was performed to detect T. gondii antigens in sera of mice. Serum samples from mice experimentally infected with T. gondii RH strain. The value of Immunoblotting in diagnosis of toxoplasmosis in acute stage of infection. The antigen bands detected in serum sample of mice were experimentally infected with T. gondii tachyzoite in immunoblotting. Six bands demonstrated on seventh post infection day six bands were identified. Similarly on sixth day four bands, on day five three bands and on fourth post infection day two bands were identified. No band was detected in control group sera. Immunoblotting is a sensitive method for diagnosis of acute stage of toxoplasmosis. (author)

  13. Detection of Toxoplasma gondii DNA in sera samples of mice experimentally infected

    Directory of Open Access Journals (Sweden)

    H. Langoni

    2006-04-01

    Full Text Available Detection of Toxoplasma gondii (T. gondii DNA in blood can help to diagnose the disease in its acute phase; however, it must be considered that hemoglobin, present in blood, can inhibit polymerase activity, making impracticable the detection of DNA in samples. Mice were experimentally infected via oral route with ME49 and BTU2 strains cysts and RH strain tachyzoites; polymerase chain reaction was used to detect T. gondii DNA in mice sera 18, 24, 48, 96, and 192 hours post infection (PI. Toxoplama gondii DNA was detected in only one animal infected with BTU2 strain, genotype III (isolated from a dog with neurological signs 18 hours PI. The agent's DNA was not detected in any sample of the other experimental groups. New studies must be carried out to verify the technique sensitivity in researches on this agent's genetic material using sera samples of acute-phase toxoplasmosis patients, especially in cases of immunosuppression.

  14. Environmental Exposures Are Important Risk Factors for Infection Toxoplasma gondii and Helicobacter pylori

    Science.gov (United States)

    Background: An estimated 70% of Americans suffer chronic infections. Helicobacter pylori and Toxoplasma gondii affect an estimated 35% and 15% of Americans, respectively. Despite their heavy burden, environmental transmission of these infections is not well understood. Object...

  15. Brain cancer mortality rates increase with Toxoplasma gondii seroprevalence in France

    Science.gov (United States)

    Vittecoq, Marion; Elguero, Eric; Lafferty, Kevin D.; Roche, Benjamin; Brodeur, Jacques; Gauthier-Clerc, Michel; Missé, Dorothée; Thomas, Frédéric

    2012-01-01

    The incidence of adult brain cancer was previously shown to be higher in countries where the parasite Toxoplasma gondii is common, suggesting that this brain protozoan could potentially increase the risk of tumor formation. Using countries as replicates has, however, several potential confounding factors, particularly because detection rates vary with country wealth. Using an independent dataset entirely within France, we further establish the significance of the association between T. gondii and brain cancer and find additional demographic resolution. In adult age classes 55 years and older, regional mortality rates due to brain cancer correlated positively with the local seroprevalence of T. gondii. This effect was particularly strong for men. While this novel evidence of a significant statistical association between T. gondii infection and brain cancer does not demonstrate causation, these results suggest that investigations at the scale of the individual are merited.

  16. Sero-prevalence of toxoplasma gondii infection among abattoir workers in Sokoto, Nigeria

    Directory of Open Access Journals (Sweden)

    M O Alayande

    2012-01-01

    Conclusion: There is need for public enlightenment to abattoir personnel on the epidemiology and significance of T. gondii infection. Further studies on toxoplasma infection in the study area are desirable.

  17. First Report of Toxoplasma gondii Prevalence in Tibetan Pigs in Tibet, China

    Science.gov (United States)

    Wu, Song-Ming; Ciren, Danba; Huang, Si-Yang; Xu, Min-Jun; Ga, Gong; Yan, Chao; Mahmoud, Mona S.; Zou, Feng-Cai

    2012-01-01

    Abstract Toxoplasma gondii infection is widely prevalent in humans and animals, including pigs throughout the world. In this study, the seroprevalence of T. gondii infection in Tibetan pigs in China was investigated for the first time. A total of 427 serum samples were collected from Tibetan pigs in Nyingchi prefecture, Tibet, between April and December 2010, and were assayed for antibodies to T. gondii using the modified agglutination test (MAT). Ninety-seven (22.72%) pigs were found to be positive with MAT titers of 1:25 or higher. Slaughter pigs had the highest seroprevalence, compared with seroprevalence in fattening pigs, growing pigs, or piglets, although the difference was not statistically significant (p≥0.05). The results of the present survey indicate that T. gondii is highly prevalent in Tibetan pigs in Tibet, which poses a significant public health concern in this unique region of the world. PMID:22651381

  18. Obtaining Highly Purified Toxoplasma gondii Oocysts by a Discontinuous Cesium Chloride Gradient

    Science.gov (United States)

    Toxoplasma gondii is an obligate intracellular protozoan pathogen that commonly infects humans. It is a well characterized apicomplexan associated with causing food- and water-borne disease outbreaks. The definitive host is the feline species where sexual replication occurs res...

  19. Toxoplasma gondii infection in interstate truck drivers: a case-control seroprevalence study.

    Science.gov (United States)

    Alvarado-Esquivel, Cosme; Pacheco-Vega, Sandy Janet; Hernández-Tinoco, Jesús; Salcedo-Jáquez, Misael; Sánchez-Anguiano, Luis Francisco; Berumen-Segovia, Luis Omar; Rábago-Sánchez, Elizabeth; Liesenfeld, Oliver

    2015-02-05

    Infection with Toxoplasma gondii can be acquired via the ingestion of undercooked or raw meat containing tissue cysts, or via ingestion of water contaminated with oocysts. Professional long distance truck driving may have epidemiological importance for food-borne infections since drivers eat out of home and in places where hygiene and cooking practices are uncertain. We aimed to determine whether interstate truck drivers in Durango, Mexico have an increased risk of infection with T. gondii as indicated by seropositivity; and to determine the socio-demographic, work, clinical, and behavioral characteristics associated with T. gondii seropositivity in interstate truck drivers. Through a case-control study design, 192 truck drivers and 192 controls from the general population of the same region matched by gender and age were examined with enzyme-linked immunoassays for the presence of anti-Toxoplasma IgG and IgM antibodies. Socio-demographic, work, clinical and behavioral characteristics from the truck drivers were obtained. Anti-T. gondii IgG antibodies were found in 23 (12.0%) of 192 truck drivers and in 13 (6.8%) of 192 controls (OR = 21.0; 95% CI: 1.23-358.38; P = 0.002). Anti-T. gondii IgM antibodies were found in 7 (3.6%) cases and in 7 (3.6%) controls (P = 1.00). The seroprevalence of T. gondii infection was higher in drivers with reflex impairment than in those without this impairment (4/13, 30.8% vs 19/179, 10.6%, respectively; P = 0.05), and in drivers with hearing impairment than in those without this impairment (3/7, 42.9% vs 20/185, 10.8%, respectively; P = 0.03). Multivariate analysis of work and behavioral characteristics of truck drives showed positive associations of T. gondii exposure with trips to the south of Mexico (OR = 3.11; 95% CI: 1.02-9.44; P = 0.04) and consumption of horse meat (OR = 5.18; 95% CI: 1.62-16.55; P = 0.005). Results suggest that interstate truck drivers may have an increased risk for T

  20. Prevalence of Toxoplasma gondii antibodies, circulating antigens and DNA in stray cats in Shanghai, China

    Directory of Open Access Journals (Sweden)

    Wang Quan

    2012-09-01

    Full Text Available Abstract Background Toxoplasma gondii is prevalent in most areas of the world and may cause abortions or neonatal complications in humans. As the only definitive host, cats play an important role in the epidemiology of the disease. Infection rates in cats, especially stray or free-living cats, are considered to be the best sentinels of the level of T. gondii in the environment. The T. gondii infection can be diagnosed in different ways with different methods depending on the target. However, little information on T. gondii infection in cats was available in Shanghai, China. Moreover reports on prevalence of circulating antigens, antibodies and DNA of T. gondii in the same study are rare. Methods In the present study, the presence of antibodies (Ab, circulating antigens (CA, and/or DNA of Toxoplasma gondii in samples from 145 stray or unwanted cats from 6 animal shelters in Shanghai (China was determined in order to estimate the prevalence of T. gondii infection, by Ab-ELISA, CA-ELISA, and nested-PCR, respectively. Results The positive rates for the antibodies, circulating antigen and DNA of T. gondii were 11.7% (17 of 145, 5.5% (8 of 145 and 5.71% (2 of 35, respectively. No cat tested was positive by both the Ab-ELISA and the CA-ELISA, but the results of the PCR were consistent with the CA-ELISA assay. Therefore, the overall estimated prevalence of toxoplasmosis was 17.2% (25 of 145. According to our results, the positive rates of specific antibodies and circulating antigen of T. gondii were significantly different between adult cats (>1 year old and juvenile cats (≤1 year old; the former was 13.5% versus 3.9% by Ab-ELISA, while the latter was 1.7% versus 23.1% by CA-ELISA. From the results obtained with all three detection methods used in this study, the rate of infection was not significantly different between male and female cats (P ≥0.05; and the overall rate was 17.9% for males versus 16.4% for females. Conclusions The results

  1. First molecular evidence of Toxoplasma gondii in opossums (Didelphis virginiana) from Yucatan, Mexico

    OpenAIRE

    Torres-Castro, M.; Noh-Pech, H.; Puerto-Hern?ndez, R.; Reyes-Hern?ndez, B.; Panti-May, A.; Hern?ndez-Betancourt, S.; Yeh-Gorocica, A.; Gonz?lez-Herrera, L.; Zavala-Castro, J.; Puerto, F.I.

    2016-01-01

    Toxoplasma gondii is an obligate intracellular parasite recognized as a causal agent of toxoplasmosis; zoonotic disease endemic in many countries worldwide, including Mexico. Different species of animals participate in the wild cycle infection, including opossums of the species Didelphis virginiana. Thirteen D. virginiana were captured in Yucatan, Mexico. Detection of T. gondii was achieved by Polymerase Chain Reaction, which determined an infection of 76.9% (10/13) in brains. Positive amplic...

  2. Prevalence Of Igg Antibodies To Encephalitozoon Cuniculi, Toxoplasma Gondii, And Sarcocystis Neurona In Domestic Cats

    OpenAIRE

    Hsu, Hsing-Ho Vasha

    2010-01-01

    Encephalitozoon cuniculi, Toxoplasma gondii and Sarcocystis neurona are intracellular parasites that infect a wide range of mammalian host species including domestic cats. The prevalence of antibodies to these parasites in cats was examined using an indirect immunofluorescence antibody assay. E. cuniculi targets the kidneys of rabbits but the prevalence of disease in cats is unknown. Chronic kidney disease (CKD) is a common cause of illness in cats. T. gondii is a widespread parasite of c...

  3. Toxoplasma gondii in sympatric domestic and wild ungulates in the Mediterranean ecosystem.

    Science.gov (United States)

    Almería, S; Cabezón, O; Paniagua, J; Cano-Terriza, D; Jiménez-Ruiz, S; Arenas-Montes, A; Dubey, J P; García-Bocanegra, I

    2018-03-01

    Toxoplasma gondii is a zoonotic protozoan of worldwide distribution. The present study provides information on risk factors affecting T. gondii infection in domestic and free-ranging wild ungulates sharing habitats in Mediterranean ecosystems in Spain. Serum samples from 482 extensively reared domestic ruminants and 2351 wild ungulates were tested for T. gondii antibodies using the modified agglutination test (MAT, cut-off 1:25). Toxoplasma gondii seroprevalence was 41.2% of 194 sheep, 18.6% of 199 cattle and 5.6% of 89 goats. The main risk factors associated with infection in livestock were the presence of cats, feeding on the ground and at stubble fields. In wild ungulates, T. gondii antibodies were detected in 10.5% of 1063 red deer, 15.6% of 294 fallow deer, 5.6% of 216 European mouflon, 5.6% of 90 Spanish ibex, 13.6% of 22 roe deer and 18.6% of 666 wild boars. The risk factors affecting T. gondii infection in wildlife were species, age and hunting season. Significantly higher seroprevalence was found in domestic ruminants, particularly in sheep, compared to the wild species tested. The present study indicates widespread exposure to T. gondii among domestic and wild ungulates in Southern Spain, with significant differences among species sharing the same ecosystem. The high seroprevalence observed in domestic ruminants, particularly in sheep, reinforces the need for farm management practices to control the risk factors associated with T. gondii infection in extensively reared livestock. Consumption of raw and undercooked food products from domestic and wildlife species may have important implications for public health.

  4. Novel triazine JPC-2067-B inhibits Toxoplasma gondii in vitro and in vivo.

    Directory of Open Access Journals (Sweden)

    Ernest J Mui

    2008-03-01

    Full Text Available Toxoplasma gondii causes substantial morbidity, mortality, and costs for healthcare in the developed and developing world. Current medicines are not well tolerated and cause hypersensitivity reactions. The dihydrotriazine JPC-2067-B (4, 6-diamino-1, 2-dihydro-2, 2-dimethyl-1-(3'(2-chloro-, 4-trifluoromethoxyphenoxypropyloxy-1, 3, 5-triazine, which inhibits dihydrofolate reductase (DHFR, is highly effective against Plasmodium falciparum, Plasmodium vivax, and apicomplexans related to T. gondii. JPC-2067-B is the primary metabolite of the orally active biguanide JPC-2056 1-(3'-(2-chloro-4-trifluoromethoxyphenyloxypropyl oxy- 5-isopropylbiguanide, which is being advanced to clinical trials for malaria. Efficacy of the prodrug JPC-2056 and the active metabolite JPC-2067-B against T. gondii and T. gondii DHFR as well as toxicity toward mammalian cells were tested.Herein, we found that JPC-2067-B is highly effective against T. gondii. We demonstrate that JPC-2067-B inhibits T. gondii growth in culture (IC50 20 nM, inhibits the purified enzyme (IC50 6.5 nM, is more efficacious than pyrimethamine, and is cidal in vitro. JPC-2067-B administered parenterally and the orally administered pro-drug (JPC-2056 are also effective against T. gondii tachyzoites in vivo. A molecular model of T. gondii DHFR-TS complexed with JPC-2067-B was developed. We found that the three main parasite clonal types and isolates from South and Central America, the United States, Canada, China, and Sri Lanka have the same amino acid sequences preserving key binding sites for the triazine.JPC-2056/JPC-2067-B have potential to be more effective and possibly less toxic treatments for toxoplasmosis than currently available medicines.

  5. Behavioral changes in Rattus norvegicus coinfected by Toxocara canis and Toxoplasma gondii

    Directory of Open Access Journals (Sweden)

    Maisa Leite de Queiroz

    2013-02-01

    Full Text Available Using an elevated plus maze apparatus and an activity cage, behavioral changes in Rattus norvegicus concomitantly infected by Toxocara canis and Toxoplasma gondii were studied, during a period of 120 days. Rats infected by Toxocara canis or Toxoplasma gondii showed significant behavioral changes; however, in the group coinfected by both parasites a behavioral pattern similar to that found in the group not infected was observed thirty days after infection, suggesting the occurrence of modulation in the behavioral response.

  6. Seropositivity and risk factors associated with Toxoplasma gondii infection in wild birds from Spain.

    Directory of Open Access Journals (Sweden)

    Oscar Cabezón

    Full Text Available Toxoplasma gondii is a zoonotic intracellular protozoan parasite of worldwide distribution that infects many species of warm-blooded animals, including birds. To date, there is scant information about the seropositivity of T. gondii and the risk factors associated with T. gondii infection in wild bird populations. In the present study, T. gondii infection was evaluated on sera obtained from 1079 wild birds belonging to 56 species (including Falconiformes (n=610, Strigiformes (n=260, Ciconiiformes (n=156, Gruiformes (n=21, and other orders (n=32, from different areas of Spain. Antibodies to T. gondii (modified agglutination test, MAT titer ≥1:25 were found in 282 (26.1%, IC(95%:23.5-28.7 of the 1079 birds. This study constitute the first extensive survey in wild birds species in Spain and reports for the first time T. gondii antibodies in the griffon vulture (Gyps fulvus, short-toed snake-eagle (Circaetus gallicus, Bonelli's eagle (Aquila fasciata, golden eagle (Aquila chrysaetos, bearded vulture (Gypaetus barbatus, osprey (Pandion haliaetus, Montagu's harrier (Circus pygargus, Western marsh-harrier (Circus aeruginosus, peregrine falcon (Falco peregrinus, long-eared owl (Asio otus, common scops owl (Otus scops, Eurasian spoonbill (Platalea leucorodia, white stork (Ciconia ciconia, grey heron (Ardea cinerea, common moorhen (Gallinula chloropus; in the International Union for Conservation of Nature (IUCN "vulnerable" Spanish imperial eagle (Aquila adalberti, lesser kestrel (Falco naumanni and great bustard (Otis tarda; and in the IUCN "near threatened" red kite (Milvus milvus. The highest seropositivity by species was observed in the Eurasian eagle owl (Bubo bubo (68.1%, 98 of 144. The main risk factors associated with T. gondii seropositivity in wild birds were age and diet, with the highest exposure in older animals and in carnivorous wild birds. The results showed that T. gondii infection is widespread and can be at a high level in many wild

  7. Seropositivity and risk factors associated with Toxoplasma gondii infection in wild birds from Spain.

    Science.gov (United States)

    Cabezón, Oscar; García-Bocanegra, Ignacio; Molina-López, Rafael; Marco, Ignasi; Blanco, Juan M; Höfle, Ursula; Margalida, Antoni; Bach-Raich, Esther; Darwich, Laila; Echeverría, Israel; Obón, Elena; Hernández, Mauro; Lavín, Santiago; Dubey, Jitender P; Almería, Sonia

    2011-01-01

    Toxoplasma gondii is a zoonotic intracellular protozoan parasite of worldwide distribution that infects many species of warm-blooded animals, including birds. To date, there is scant information about the seropositivity of T. gondii and the risk factors associated with T. gondii infection in wild bird populations. In the present study, T. gondii infection was evaluated on sera obtained from 1079 wild birds belonging to 56 species (including Falconiformes (n=610), Strigiformes (n=260), Ciconiiformes (n=156), Gruiformes (n=21), and other orders (n=32), from different areas of Spain. Antibodies to T. gondii (modified agglutination test, MAT titer ≥1:25) were found in 282 (26.1%, IC(95%:)23.5-28.7) of the 1079 birds. This study constitute the first extensive survey in wild birds species in Spain and reports for the first time T. gondii antibodies in the griffon vulture (Gyps fulvus), short-toed snake-eagle (Circaetus gallicus), Bonelli's eagle (Aquila fasciata), golden eagle (Aquila chrysaetos), bearded vulture (Gypaetus barbatus), osprey (Pandion haliaetus), Montagu's harrier (Circus pygargus), Western marsh-harrier (Circus aeruginosus), peregrine falcon (Falco peregrinus), long-eared owl (Asio otus), common scops owl (Otus scops), Eurasian spoonbill (Platalea leucorodia), white stork (Ciconia ciconia), grey heron (Ardea cinerea), common moorhen (Gallinula chloropus); in the International Union for Conservation of Nature (IUCN) "vulnerable" Spanish imperial eagle (Aquila adalberti), lesser kestrel (Falco naumanni) and great bustard (Otis tarda); and in the IUCN "near threatened" red kite (Milvus milvus). The highest seropositivity by species was observed in the Eurasian eagle owl (Bubo bubo) (68.1%, 98 of 144). The main risk factors associated with T. gondii seropositivity in wild birds were age and diet, with the highest exposure in older animals and in carnivorous wild birds. The results showed that T. gondii infection is widespread and can be at a high level in

  8. Epidemiology and pathology of Toxoplasma gondii in free-ranging California sea lions (Zalophus californianus).

    Science.gov (United States)

    Carlson-Bremer, Daphne; Colegrove, Kathleen M; Gulland, Frances M D; Conrad, Patricia A; Mazet, Jonna A K; Johnson, Christine K

    2015-04-01

    The coccidian parasite Toxoplasma gondii infects humans and warm-blooded animals worldwide. The ecology of this parasite in marine systems is poorly understood, although many marine mammals are infected and susceptible to clinical toxoplasmosis. We summarized the lesions associated with T. gondii infection in the California sea lion (Zalophus californianus) population and investigated the prevalence of and risk factors associated with T. gondii exposure, as indicated by antibody. Five confirmed and four suspected cases of T. gondii infection were identified by analysis of 1,152 medical records of necropsied sea lions from 1975-2009. One suspected and two confirmed cases were identified in aborted fetuses from a sea lion rookery. Toxoplasmosis was the primary cause of death in five cases, including the two fetuses. Gross and histopathologic findings in T. gondii-infected sea lions were similar to those reported in other marine mammals. The most common lesions were encephalitis, meningitis, and myocarditis. The antibody prevalence in stranded, free-ranging sea lions for 1998-2009 was 2.5% (±0.03%; IgG titer 640). There was an increase in odds of exposure in sea lions with increasing age, suggesting cumulative risk of exposure and persistent antibody over time. The occurrence of disseminated T. gondii infection in aborted fetuses confirms vertical transmission in sea lions, and the increasing odds of exposure with age is consistent with additional opportunities for horizontal transmission in free-ranging sea lions over time. These data suggest that T. gondii may have two modes of transmission in the sea lion population. Overall, clinical disease was uncommon in our study which, along with low prevalence of T. gondii antibody, suggests substantially less-frequent exposure and lower susceptibility to clinical disease in California sea lions as compared to sympatric southern sea otters (Enhydra lutris nereis).

  9. THE ROLE OF HORMONES ON Toxoplasma gondii INFECTION: A SYSTEMATIC REVIEW

    Directory of Open Access Journals (Sweden)

    María De La Luz Galván-Ramírez

    2014-10-01

    Full Text Available Background: Toxoplasma gondii is the causal agent of toxoplasmosis in which one third of the world’s population has been infected. In pregnant women, it may cause abortion and severe damage to the fetal central nervous system. During pregnancy, the prevalence of toxoplasmosis increases throughout the second and third quarter of gestation, simultaneously progesterone and 17β-estradiol also increase. Thus, it has been suggested that these hormones can aggravate or reduce parasite reproduction. The aim of this study was reviewing the relationship between hormones and infection caused by T. gondii in several experimental animal models and humans, focused mainly on: a congenital transmission, b parasite reproduction, c strain virulence, d levels of hormone in host induced by T. gondii infection and e participation of hormone receptors in Toxoplasma gondii infection.Are the hormones specific modulators of T. gondii infection?A systematic review methodology was used to consult several databases (Pub Med, Lilacs, Medline, Science direct, Scielo, Ebsco, Sprinker, Wiley and Google Scholar dated from September, 2013 to March, 2014. Results: 30 studies were included; eight studies in humans and 22 in animals and cell cultures. In the human studies, the most studied hormones were testosterone, progesterone, prolactin and 17-ß estradiol. Type I (RH and BK and Type II (Prugniaud, SC, ME49,T45, P78 and T38 were the most frequent experimental strains. Conclusions: Thirty-five years have passed since the first studies regarding Toxoplasma gondii infection and its relationship with hormones. This systematic review suggests that hormones modulate Toxoplasma gondii infection in different animal models. However, given that data were not comparable, further studies are required to determine the mechanism of hormone action in the Toxoplasma gondii infectious process.

  10. An unusual cause of acute respiratory distress in a patient with AIDS: primary infection with Toxoplasma gondii.

    Science.gov (United States)

    Charles, Pierre Emmanuel; Doise, Jean Marc; Quenot, Jean Pierre; Aube, Herve; Dalle, Frederic; Bour, Jean Baptiste; Chavanet, Pascal; Blettery, Bernard

    2003-01-01

    Hypoxemic pneumonia in AIDS patients is mainly caused by Pneumocystis carinii, Toxoplasma gondii and CMV, although the significance of CMV recovery in BALF is often unclear. Since lung involvement generally occurs during reactivation, T. gondii is not expected to be demonstrated in patients without evidence of past infection with this agent. We report a fatal case of pneumonia revealing a T. gondii primary infection diagnosed thanks to the PCR analysis of the BALF.

  11. Spread and genotype of Toxoplasma gondii in naturally infected alpine chamois (Rupicapra r. rupicapra).

    Science.gov (United States)

    Formenti, Nicoletta; Gaffuri, Alessandra; Trogu, Tiziana; Viganò, Roberto; Ferrari, Nicola; Lanfranchi, Paolo

    2016-05-01

    The complex life cycle of Toxoplasma gondii involves many animal species, raising zoonotic, economic, and conservation issues. This complexity is reflected in the molecular structure of T. gondii, whose different genotypes differ in pathogenicity. Among the intermediate hosts of T. gondii, wild ungulates may be a source of human infection. Despite intense hunting activity and the consumption of raw or undercooked meat, little information is available on the spread of T. gondii and the distribution of its genotypes in these species, including the alpine chamois (Rupicapra r. rupicapra). Ninety-three sera and 50 brain tissues from chamois were sampled (1) to investigate the spread of T. gondii with serological and molecular analyses, and (2) to genotype the strains with a restriction fragment length polymorphism analysis of the SAG2 locus. The prevalence of T. gondii was low on both serological (3.2 %) and molecular (2 %) analyses, and infections were concentrated in individuals >1 year old. These findings demonstrate the sporadic presence of the protozoan in this species on consistent diagnostic tests. Horizontal transmission seems to be the main route of infection, and cats are the only definitive host in the study area. This prevalence suggests that the environment of the chamois is less contaminated with oocysts than environments close to human settlements. The SAG2 type II genotype was detected in this species for the first time. Although this genotype is predominant in human toxoplasmosis, these results suggest that the chamois is a minor source of human infection.

  12. Detection of antibodies against Toxoplasma gondii in Mirounga leonina Linnaeus, 1758 (Pinnipedia, Phocidae from Elephant Island

    Directory of Open Access Journals (Sweden)

    Tony Silveira

    2016-03-01

    Full Text Available Objective: To investigate the presence of antibodies against Toxoplasma gondii (T. gondii in Mirounga leonina (M. leonina Linnaeus from Elephant Island, Antarctica. Methods: The animals were anesthetized, restrained, measured, weighed and had their blood collected by venipuncture of intervertebral lumbar epidural vein. Blood samples were collected from 102 individuals. Indirect hemagglutination and serum dilution at a proportion of 1:25 was used for specific immunoglobulin G anti-T. gondii detection. Results: Only one (0.98% specimen, a newly weaned calf, was seropositive. Conclusions: This study is the highest serological survey for antibody detection against T. gondii in M. leonina. The results suggest a low level of exposure to T. gondii, probably due to the absence of felids in the study area. The seropositivity presented by the elephant seal may be related to the presence of oocysts in water or cysts in their preys. Despite being reported the presence of the parasite in fish and molluscs, there are no records of tissue cysts or oocysts in squid or fish of the diet of M. leonina. Thus, further parasitological studies focused on preys of elephant seals are needed for a better understanding of infection of M. leonina by T. gondii.

  13. Toxoplasma gondii transmission by artificial insemination in sheep with experimentally contaminated frozen semen.

    Science.gov (United States)

    Consalter, Angélica; Silva, Andressa F; Frazão-Teixeira, Edwards; Matos, Luis F; de Oliveira, Francisco C R; Leite, Juliana S; Silva, Franciele B F; Ferreira, Ana M R

    2017-03-01

    Toxoplasma gondii is a parasite considered one of the major causes of reproductive problems in sheep. Furthermore, the presence of the agent in ram semen urges the possibility of sexual transmission in this species. The aim of this study was to evaluate if ram's frozen semen spiked with T. gondii tachyzoites would be able to cause infection in sheep by laparoscopic artificial insemination (AI). Nine ewes tested seronegative to anti-T. gondii antibodies by the modified agglutination test (MAT) were superovulated and inseminated to collect embryos. Animals were divided into two groups: G1 (n = 5), ewes inseminated with semen containing 4 × 10 7 tachyzoites; and G2 (n = 4), ewes inseminated with tachyzoite-free semen (control group). To confirm infection, ewe's blood samples were collected on days -14, -7, 0, 7, 14, 21, 28, 35, 49 and 57 after AI for analysis by MAT and PCR. Tissue samples of these ewes were also collected for histopathology and immunohistochemistry (IHC). Seven days after AI, all ewes of group G1 had specific antibodies to T. gondii, while those of G2 were negative. Toxoplasma gondii DNA was detected in the blood of one ewe and parasites were observed in tissues of all five animals inseminated with contaminated semen, indicating that semen freezing protocol does not affect T. gondii transmission by artificial insemination in sheep. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Seroprevalence of Toxoplasma gondii and Neospora caninum in red deer from Central Italy

    Directory of Open Access Journals (Sweden)

    Guido Rocchigiani

    2016-09-01

    Full Text Available Neospora caninum and Toxoplasma gondii are cosmopolite protozoan parasites impacting on human and animal health. In particular, T. gondii commonly infects human beings and all warm-blooded animals, while N. caninum is responsible for bovine abortion and neuromuscular disease in dogs. The aim of the presented survey was to evaluate the occurrence and prevalence of these parasites in the most numerous Italian red deer population. The sera of 60 red deer ( Cervus elaphus inhabiting Central Italy (43°56’N 10°55’E and killed by selective hunting were examined using an indirect fluorescent antibody test (IFAT for both N. caninum and T. gondii antibodies. White blood cells (buffy coat were also checked by PCR and T. gondii DNA was genotyped. Thirteen out of 60 sera (22% scored positive for Toxoplasma, 17 samples (28% were Neospora positive. Coinfection was recorded in 5 cases (8%. T. gondii (genotype II and N. caninum DNA was detected in one and 3 samples of buffy coat, respectively. The presented study is the first to examine the occurrence of these parasites in the most numerous red deer Italian population, confirming this animal species as carrier of the investigated pathogens. These animals spread near human settlements, co-inhabiting with final hosts of [i]T. gondii[/i] and N. caninum and could contribute to their transmission to domestic ruminants and humans. In particular, the seroprevalence value for N. caninum was the highest among European records.

  15. Toxoplasmosis in dogs: first report of Toxoplasma gondii infection in any animal species in Angola.

    Science.gov (United States)

    Lopes, Ana Patrícia; Granada, Sara; Oliveira, Ana Cristina; Brancal, Hugo; Dubey, Jitender P; Cardoso, Luís; Vilhena, Hugo

    2014-10-01

    Despite the worldwide importance of zoonotic parasite Toxoplasma gondii, nothing is known of toxoplasmosis in animals in Angola. The present study aimed at estimating the seroprevalence and also at assessing correlates of T. gondii infection in pet dogs from Luanda, Angola. Dogs (n = 103) brought to a veterinary clinic in the city of Luanda were investigated. Serum samples were tested for antibodies to T. gondii with a modified agglutination test (MAT) commercial kit, at serial dilutions of 1∶20 to 1∶160. In accordance with the established cutoff value (MAT ≧20), 16 dogs [15·5%; 95% confidence interval (CI): 9·2-24·0%] had antibodies to T. gondii: 10 had a titer of 20, two had a titer of 40, and four had a titer of 80. Age (≧12 months) was found to be a risk factor for infection [odds ratio (OR) = 9·23; 95% CI: 1·16-73·27). For each 1-year increase in age, the risk of a dog being found seropositive significantly increased by an OR of 1·18 (95% CI: 1·02-1·36). The present study, which represents the first serological survey of T. gondii in any animal species from Angola, reveals a 15·5% seroprevalence of infection in pet dogs in Luanda. Further studies are needed to better understand the epidemiology of zoonotic T. gondii infection in Luanda and also in Angola.

  16. Risk factors for Toxoplasma gondii and Neospora caninum seropositivity in buffaloes in Paraiba State, Brazil

    Directory of Open Access Journals (Sweden)

    Arthur Willian de Lima Brasil

    Full Text Available Abstract The aims of this survey were to determine the frequency of anti-Toxoplasma gondii and anti-Neospora caninum antibodies and to identify the risk factors associated with seropositivity among buffaloes in the state of Paraíba, Brazil. This survey included 136 buffaloes belonging to 14 herds. To detect anti-T. gondii and anti-N. caninum antibodies, the indirect fluorescent antibody test (IFAT was used. Among the 136 samples analyzed, 17 (12.5% were positive for anti-T. gondii antibodies with titers ranging from 64 to 1,024, and 26 (19.1% for anti-N. caninum with titers from 200 to 1,600. Animals seropositive for both T. gondii and N. caninum were found in 10 of the 14 herds (71.4%. Semi-intensive management systems (odds ratio = 2.99 and presence of pigs (odds ratio = 4.33 were identified as risk factors for T. gondii and N. caninum, respectively. It can be suggested that T. gondii and N. caninum are widespread in buffaloes in Paraíba, and that additional surveys are needed in order to ascertain the importance of these agents for this species and for pigs, and the influence of the farming type on occurrences of seropositive animals.

  17. Seroprevalence of Toxoplasma gondii in domestic sheep in Oaxaca State, Mexico.

    Science.gov (United States)

    Alvarado-Esquivel, C; Estrada-Malacón, M A; Reyes-Hernández, S O; Pérez-Ramírez, J A; Trujillo-López, J I; Villena, I; Dubey, J P

    2013-02-01

    The seroprevalence of Toxoplasma gondii infection in sheep in southern Mexico is largely unknown. Antibodies to T. gondii were determined in serum samples of 429 sheep from 4 farms in 2 geographical regions in Oaxaca State, Mexico, using the modified agglutination test (MAT); 99 (23.1%) of the 429 sheep had positive MAT titers: 1:25 in 35, 1:50 in 18, 1:100 in 7, 1:200 in 1, 1:400 in 3, 1:800 in 10, 1:1,600 in 5, and 1:3,200, or higher, in 20. Seroprevalence of T. gondii infection varied with management, breed of sheep, and location. It was significantly higher in sheep raised under semi-intensive (grazed on cultivated pasture and hay) conditions than in those raised under semi-extensive conditions (grazed on communal natural grass land). The seroprevalence of T. gondii infection was significantly higher in mixed-breed sheep than in pure breeds. Sheep raised in temperate climate in municipalities at 1,560-1,600 m above sea level (Central Valley region) had a significantly higher seroprevalence of T. gondii infection than those raised in semiarid and warm-humid climates in municipalities at 1,020-1,080 m of altitude (Cañada region) (29.8% vs. 7.1%, respectively). This is the first report of T. gondii infection in sheep in Oaxaca State, Mexico.

  18. Seroprevalence of Toxoplasma gondii infection in domestic sheep in Durango State, Mexico.

    Science.gov (United States)

    Alvarado-Esquivel, C; García-Machado, C; Alvarado-Esquivel, D; Vitela-Corrales, J; Villena, I; Dubey, J P

    2012-04-01

    The seroprevalence of Toxoplasma gondii infection in sheep (Ovis aries) in northern Mexico is largely unknown. Antibodies to T. gondii were determined in serum samples from 511 sheep from 8 farms in Durango State, Mexico, using the modified agglutination test (MAT). Sheep were raised in 3 geographical regions, i.e., mountainous (n  =  68), semi-desert (n  =  132), and valley (n  =  311). Overall, T. gondii antibodies were found in 77 (15.1%) of 511 sheep, with MAT titers of 1∶25 in 27, 1∶50 in 10, 1∶100 in 11, 1∶200 in 11, 1∶400 in 8, 1∶800 in 3, 1∶1,600 in 4, and 1∶3,200 in 3. The seroprevalence of T. gondii infection increased significantly with age, indicating post-natal transmission. In contrast, gender, breed, flock size, and geographic region did not significantly influence the seroprevalence. Seropositive sheep were found in 7 of 8 farms sampled. This is the first report of T. gondii infection in sheep in Durango State, Mexico. Results indicate that infected sheep are probably an important source of T. gondii infection for humans in Durango State.

  19. Toxoplasma gondii and Neospora caninum seroprevalences in domestic South American camelids of the Peruvian Andes.

    Science.gov (United States)

    Chávez-Velásquez, Amanda; Aguado-Martínez, Adriana; Ortega-Mora, Luis M; Casas-Astos, Eva; Serrano-Martínez, Enrique; Casas-Velásquez, Gina; Ruiz-Santa-Quiteria, Jose A; Alvarez-García, Gema

    2014-10-01

    The objective of this study was to investigate the presence of Toxoplasma gondii- and Neospora caninum-specific antibodies in domestic South American camelids (SAC) (llamas and alpacas) from the Peruvian Andes through a cross-sectional study. A wide panel of serum samples collected from 1,845 llamas and 2,874 alpacas from the two main SAC production areas of Peru was selected. Immunofluorescence antibody technique was employed to detect and titrate specific anti-T. gondii and anti-N. caninum immunoglobulins G in serum samples. The association between T. gondii and N. caninum seroprevalence and the geographical origin (Central and South Peruvian Andes) was evaluated. Anti-T. gondii antibodies were found in 460 (24.9 %) llamas and 706 (24.6 %) alpacas, whereas anti-N. caninum antibodies were detected in 153 (8.3 %) llamas and 425 (14.8 %) alpacas. Toxoplasma gondii infection was strongly associated with the South Peruvian Andes where moderate climate conditions, larger human population, compared to the Central region, and the presence of wildlife definitive hosts could favor horizontal transmission to SAC. In contrast, N. caninum infection was not associated with the geographical region. These results indicate that T. gondii and N. caninum infections are highly and moderately widespread, respectively, in both species of domestic SAC studied in the sampled areas and appropriate control measures should be undertaken to reduce the prevalence of both parasitic infections.

  20. Miscarriage history and Toxoplasma gondii infection: A cross-sectional study in women in Durango City, Mexico.

    Science.gov (United States)

    Alvarado-Esquivel, C; Pacheco-Vega, S J; Hernández-Tinoco, J; Centeno-Tinoco, M M; Beristain-García, I; Sánchez-Anguiano, L F; Liesenfeld, O; Rábago-Sánchez, E; Berumen-Segovia, L O

    2014-06-01

    Through a cross-sectional study design, 326 women with a history of miscarriage were examined for anti-Toxoplasma gondii IgG and IgM antibodies in Durango City, Mexico. Prevalence association with sociodemographic, clinical, and behavioral characteristics in women with miscarriage was also investigated. Twenty-two (6.7%) of the 326 women studied had anti-T. gondii IgG antibodies and two (0.6%) were also positive for anti-T. gondii IgM antibodies. Seroprevalence of T. gondii infection was not influenced by age, birth place, occupation, educational level, or socioeconomic status. In contrast, logistic regression showed that T. gondii exposure was associated with consumption of raw or undercooked meat (OR = 6.84; 95% CI: 1.04-44.95; P = 0.04) and consumption of chicken brains (OR = 18.48; 95% CI: 1.26-269.43; P = 0.03). This is the first study on the seroepidemiology of T. gondii infection in women with a history of miscarriage in Northern Mexico. Of interest, we also observed an association of T. gondii exposure with consumption of chicken brains. Contributing factors for T. gondii exposure found in the present study should be taken into consideration for public health measures to avoid infection with T. gondii and its sequelae.

  1. Stillbirth history and Toxoplasma gondii infection in women attending public health centers in a northern Mexican City

    Science.gov (United States)

    Alvarado-Esquivel, C.; Pacheco-Vega, S. J.; Salcedo-Jaquez, M.; Sánchez-Anguiano, L. F.; Hernández-Tinoco, J.; Rábago-Sánchez, E.; Centeno-Tinoco, M. M.; Flores-Garcia, I. D.; Ramos-Nevarez, A.; Cerrillo-Soto, S. M.; Guido-Arreola, C. A.; Beristain-García, I.; Liesenfeld, O.; Berumen-Segovia, L. O.; Saenz-Soto, L.; Sifuentes-Álvarez, A.

    2015-01-01

    Through a cross-sectional study design, 150 women attending public health centers with a history of stillbirths were examined for anti-Toxoplasma gondii IgG and IgM antibodies in Durango City, Mexico. Bivariate and multivariate analyses were used to assess the association of T. gondii seropositivity with the characteristics of the women with stillbirth history. Of the 150 women (mean age: 32.09 ± 9.16 years) studied, 14 (9.3%) had anti-T. gondii IgG antibodies and six (42.9%) of them were also positive for anti-T. gondii IgM antibodies. Multivariate analysis showed that T. gondii seropositivity was associated with high frequency (4–7 days a week) of eating meat (OR = 5.52; 95% CI: 1.48–20.59; P = 0.01), history of lymphadenopathy (OR = 4.52; 95% CI: 1.14–17.82; P = 0.03), and history of surgery (OR = 8.68; 95% CI: 1.04–72.15; P = 0.04). This is the first study on the seroepidemiology of T. gondii infection in women with a history of stillbirths in Mexico. The association of T. gondii exposure with a history of surgery warrants for further research. Risk factors for T. gondii infection found in the present survey may help to design optimal educational programs to avoid T. gondii infection. PMID:26185685

  2. Sensitivity and specificity of various serologic tests for detection of Toxoplasma gondii infection in naturally infected sows

    DEFF Research Database (Denmark)

    Dubey, J.P.; Thulliez, P.; Weigel, R.M.

    1995-01-01

    The sensitivity and specificity of various serologic tests for antibodies to Toxoplasma gondii were compared in 1,000 naturally exposed sows, using isolation of viable T gondii as the definitive test. Serum samples obtained from heart blood of 1,000 sows from Iowa were examined for T gondii...... antibodies by use of the modified agglutination test (MAT), latex agglutination test (LAT), indirect hemagglutination test (IHAT), and ELISA. Toxoplasma gondii was isolated from 170 hearts of 1,000 sows by bioassays in mice and cats. The percentage of samples diagnosed as positive for each of the serologic...

  3. Prevalence of Toxoplasma gondii antibodies in domestic donkeys (Equus asinus) in Durango, Mexico slaughtered for human consumption.

    Science.gov (United States)

    Alvarado-Esquivel, Cosme; Alvarado-Esquivel, Domingo; Dubey, Jitender P

    2015-01-17

    Nothing is known about Toxoplasma gondii prevalence in donkeys in Mexico. Meat from donkey is consumed by humans in Mexico and also exported to other countries. We sought to determine the presence of antibodies against T. gondii in 239 domestic donkeys (Equus asinus) for slaughter in Durango, Mexico using the modified agglutination test (MAT). Donkeys were sampled in four premises (trade centers) where donkeys were gather for shipment to abattoirs in other Mexican states. Antibodies to T. gondii were found in 26 (10.9%) of 239 donkeys, with MAT titers of 1:25 in 7, 1:50 in 11, 1:100 in 6, and 1:200 in 2. Seropositive donkeys were found in three (75%) of the four gathering premises studied. Seroprevalence in donkeys varied from 0% to 23.1% among gathering premises. The seroprevalence of T. gondii infection was comparable among donkeys regardless their age, sex or health status. Seropositivity to T. gondii was found in donkeys between 1 to 12 years old. Multivariate analysis showed that seropositivity to T. gondii was associated with the gathering premises (OR = 1.58; 95% CI: 1.11-2.24; P = 0.009). This is the first report of T. gondii infection in donkeys in Mexico. Results indicate that consumption of undercooked or raw meat from T. gondii-infected donkeys is potentially a source of T. gondii infection for humans.

  4. Human GBP1 does not localize to pathogen vacuoles but restricts Toxoplasma gondii.

    Science.gov (United States)

    Johnston, Ashleigh C; Piro, Anthony; Clough, Barbara; Siew, Malvin; Virreira Winter, Sebastian; Coers, Jörn; Frickel, Eva-Maria

    2016-08-01

    Guanylate binding proteins (GBPs) are a family of large interferon-inducible GTPases that are transcriptionally upregulated upon infection with intracellular pathogens. Murine GBPs (mGBPs) including mGBP1 and 2 localize to and disrupt pathogen-containing vacuoles (PVs) resulting in the cell-autonomous clearing or innate immune detection of PV-resident pathogens. Human GBPs (hGBPs) are known to exert antiviral host defense and activate the NLRP3 inflammasome, but it is unclear whether hGBPs can directly recognize and control intravacuolar pathogens. Here, we report that endogenous or ectopically expressed hGBP1 fails to associate with PVs formed in human cells by the bacterial pathogens Chlamydia trachomatis or Salmonella typhimurium or the protozoan pathogen Toxoplasma gondii. While we find that hGBP1 expression has no discernible effect on intracellular replication of C. trachomatis and S. typhimurium, we observed enhanced early Toxoplasma replication in CRISPR hGBP1-deleted human epithelial cells. We thus identified a novel role for hGBP1 in cell-autonomous immunity that is independent of PV translocation, as observed for mGBPs. This study highlights fundamental differences between human and murine GBPs and underlines the need to study the functions of GBPs at cellular locations away from PVs. © 2016 The Authors Cellular Microbiology Published by John Wiley & Sons Ltd.

  5. Induction of Autophagy interferes the tachyzoite to bradyzoite transformation of Toxoplasma gondii.

    Science.gov (United States)

    Li, Xiangzhi; Chen, Di; Hua, Qianqian; Wan, Yujing; Zheng, Lina; Liu, Yangyang; Lin, Jiaxin; Pan, Changwang; Hu, Xin; Tan, Feng

    2016-04-01

    Autophagy process in Toxoplasma gondii plays a vital role in regulating parasite survival or death. Thus, once having an understanding of certain effects of autophagy on the transformation of tachyzoite to bradyzoite this will allow us to elucidate the function of autophagy during parasite development. Herein, we used three TgAtg proteins involved in Atg8 conjugation system, TgAtg3, TgAtg7 and TgAtg8 to evaluate the autophagy level in tachyzoite and bradyzoite of Toxoplasma in vitro based on Pru TgAtg7-HA transgenic strains. We showed that both TgAtg3 and TgAtg8 were expressed at a significantly lower level in bradyzoites than in tachyzoites. Importantly, the number of parasites containing fluorescence-labelled TgAtg8 puncta was significantly reduced in bradyzoites than in tachyzoites, suggesting that autophagy is downregulated in Toxoplasma bradyzoite in vitro. Moreover, after treatment with drugs, bradyzoite-specific gene BAG1 levels decreased significantly in rapamycin-treated bradyzoites and increased significantly in 3-MA-treated bradyzoites in comparison with control bradyzoites, indicating that Toxoplasma autophagy is involved in the transformation of tachyzoite to bradyzoite in vitro. Together, it is suggested that autophagy may serve as a potential strategy to regulate the transformation.

  6. Possible role of Toxoplasma gondii in brain cancer through modulation of host microRNAs

    Directory of Open Access Journals (Sweden)

    Thirugnanam Sivasakthivel

    2013-02-01

    Full Text Available Abstract Background The obligate intracellular protozoan parasite Toxoplasma gondii infects humans and other warm-blooded animals and establishes a chronic infection in the central nervous system after invasion. Studies showing a positive correlation between anti-Toxoplasma antibodies and incidences of brain cancer have led to the notion that Toxoplasma infections increase the risk of brain cancer. However, molecular events involved in Toxoplasma induced brain cancers are not well understood. Presentation of the hypothesis Toxoplasma gains control of host cell functions including proliferation and apoptosis by channelizing parasite proteins into the cell cytoplasm and some of the proteins are targeted to the host nucleus. Recent studies have shown that Toxoplasma is capable of manipulating host micro RNAs (miRNAs, which play a central role in post-transcriptional regulation of gene expression. Therefore, we hypothesize that Toxoplasma promotes brain carcinogenesis by altering the host miRNAome using parasitic proteins and/or miRNAs. Testing the hypothesis The miRNA expression profiles of brain cancer specimens obtained from patients infected with Toxoplasma could be analyzed and compared with that of normal tissues as well as brain cancer tissues from Toxoplasma uninfected individuals to identify dysregulated miRNAs in Toxoplasma-driven brain cancer cells. Identified miRNAs will be further confirmed by studying cancer related miRNA profiles of the different types of brain cells before and after Toxoplasma infection using cell lines and experimental animals. Expected outcome The miRNAs specifically associated with brain cancers that are caused by Toxoplasma infection will be identified. Implications of the hypothesis Toxoplasma infection may promote initiation and progression of cancer by modifying the miRNAome in brain cells. If this hypothesis is true, the outcome of this research would lead to the development of novel biomarkers and

  7. Antibody Detection, Isolation, Genotyping, and Virulence of Toxoplasma gondii in Captive Felids from China

    Directory of Open Access Journals (Sweden)

    Yu-Rong Yang

    2017-07-01

    Full Text Available The felids are the only definitive hosts of Toxoplasma gondii, which could excrete oocysts into the environment and provide an infection source for toxoplasmosis in various warm-blooded animal species, particularly the captive felids that live close to human communities. The infection rate of the captive felids is a perfect standard in detecting the presence of Toxoplasma gondii oocysts in the environment. In this study, sera or tissue samples from zoo (1 young tiger, 2 adult tigers, 6 young lions, farm (10 masked palm civets, and pet hospital (28 cats from Henan Province (China were collected. The sera (n = 47 were tested for immunoglobulin G (IgG antibodies against T. gondii by using modified agglutination test (MAT, whereas the hearts tissue (n = 40 were bioassayed in mice to isolate T. gondii strains. The genotype was distinguished by using PCR-RFLP of 10 loci (SAG1, SAG2, SAG3, GRA6, BTUB, L358, c22-8, PK1, c29-2, and Apico. The detection rate for the T. gondii antibody in captive felids was 21.3% (10/47. One viable T. gondii strain (TgCatCHn4 was obtained from a cat heart tissue, and its genotype was ToxoDB#9. The oocysts of ToxoDB#9 were collected from a T. gondii-free cat. The virulence of TgCatCHn4 was low and no cysts were detected in the brain of mice at 60 days post-inoculation. The finding of the present study suggested a widespread exposure of T. gondii for felids in Henan Province of central China, particularly those from the zoological gardens and homes. ToxoDB#9 was the predominant strain in China. Preventive measures against T. gondii oocyst contamination of various components of the environment should thus be implemented, including providing pre-frozen meat, well-cooked cat food, cleaned fruits and vegetables, monitoring birds and rodents, inactive T. gondii oocysts in felids feces, and proper hygiene.

  8. Toxoplasma gondii, Neospora caninum, Sarcocystis neurona, and Sarcocystis canis-like infections in marine mammals

    Science.gov (United States)

    Dubey, J.P.; Zarnke, R.; Thomas, N.J.; Wong, S.K.; Vanbonn, W.; Briggs, M.; Davis, J.W.; Ewing, R.; Mense, M.; Kwok, O.C.H.; Romand, S.; Thulliez, P.

    2003-01-01

    Toxoplasma gondii, Neospora caninum, Sarcocystis neurona, and S. canis are related protozoans that can cause mortality in many species of domestic and wild animals. Recently, T. gondii and S. neurona were recognized to cause encephalitis in marine mammals. As yet, there is no report of natural exposure of N. caninum in marine mammals. In the present study, antibodies to T. gondii and N. caninum were assayed in sera of several species of marine mammals. For T. gondii, sera were diluted 1:25, 1:50, and 1:500 and assayed in the T. gondii modified agglutination test (MAT). Antibodies (MAT a?Y1:25) to T. gondii were found in 89 of 115 (77%) dead, and 18 of 30 (60%) apparently healthy sea otters (Enhydra lutris), 51 of 311 (16%) Pacific harbor seals (Phoca vitulina), 19 of 45 (42%) sea lions (Zalophus californianus), 5 of 32 (16%) ringed seals (Phoca hispida), 4 of 8 (50%) bearded seals (Erignathus barbatus), 1 of 9 (11.1%) spotted seals (Phoca largha), 138 of 141 (98%) Atlantic bottlenose dolphins (Tursiops truncatus), and 3 of 53 (6%) walruses (Odobenus rosmarus). For N. caninum, sera were diluted 1:40, 1:80, 1:160, and 1:320 and examined with the Neospora agglutination test (NAT) using mouse-derived tachyzoites. NAT antibodies were found in 3 of 53 (6%) walruses, 28 of 145 (19%) sea otters, 11 of 311 (3.5%) harbor seals, 1 of 27 (3.7%) sea lions, 4 of 32 (12.5%) ringed seals, 1 of 8 (12.5%) bearded seals, and 43 of 47 (91%) bottlenose dolphins. To our knowledge, this is the first report of N. caninum antibodies in any marine mammal, and the first report of T. gondii antibodies in walruses and in ringed, bearded, spotted, and ribbon seals. Current information on T. gondii-like and Sarcocystis-like infections in marine mammals is reviewed. New cases of clinical S. canis and T. gondii infections are also reported in sea lions, and T. gondii infection in an Antillean manatee (Trichechus manatus manatus).

  9. Serological study for antibodies to toxoplasma gondii in Jakarta, Indonesia.

    Science.gov (United States)

    Gandahusada, S

    1978-09-01

    A total of 280 sera from medical students, laboratory personnel from the University of Indonesia and other persons living in Jakarta were tested for antibodies to Toxoplasma gondii by the indirect hemagglutination test. Antibody titers equal to or greater than 1:256 were considered positive and were detected in 35 or 12.5% of the persons tested. The sero-positivity rates were not significant between 178 males (13.5%) and 102 females (10.8%) but were significantly different between persons of Indonesian ancestry (14.3%) and those of Chinese ancestry (2.3%). No correlation could be found between ownership of domestic cats and eating habits and positive titers.

  10. Use and abuse of dendritic cells by Toxoplasma gondii

    Science.gov (United States)

    Sanecka, Anna; Frickel, Eva-Maria

    2012-01-01

    The ubiquitous apicomplexan parasite Toxoplasma gondii stimulates its host’s immune response to achieve quiescent chronic infection. Central to this goal are host dendritic cells. The parasite exploits dendritic cells to disseminate through the body, produce pro-inflammatory cytokines, present its antigens to the immune system and yet at the same time subvert their signaling pathways in order to evade detection. This carefully struck balance by Toxoplasma makes it the most successful parasite on this planet. Recent progress has highlighted specific parasite and host molecules that mediate some of these processes particularly in dendritic cells and in other cells of the innate immune system. Critically, there are several important factors that need to be taken into consideration when concluding how the dendritic cells and the immune system deal with a Toxoplasma infection, including the route of administration, parasite strain and host genotype. PMID:23221473

  11. The Crystal Structure of Toxoplasma gondii Pyruvate Kinase 1

    Energy Technology Data Exchange (ETDEWEB)

    Bakszt, R.; Wernimont, A; Allali-Hassani, A; Mok, M; Hills, T; Hui, R; Pizarro, J

    2010-01-01

    Pyruvate kinase (PK), which catalyzes the final step in glycolysis converting phosphoenolpyruvate to pyruvate, is a central metabolic regulator in most organisms. Consequently PK represents an attractive therapeutic target in cancer and human pathogens, like Apicomplexans. The phylum Aplicomplexa, a group of exclusively parasitic organisms, includes the genera Plasmodium, Cryptosporidium and Toxoplasma, the etiological agents of malaria, cryptosporidiosis and toxoplasmosis respectively. Toxoplasma gondii infection causes a mild illness and is a very common infection affecting nearly one third of the world's population. We have determined the crystal structure of the PK1 enzyme from T. gondii, with the B domain in the open and closed conformations. We have also characterized its enzymatic activity and confirmed glucose-6-phosphate as its allosteric activator. This is the first description of a PK enzyme in a closed inactive conformation without any bound substrate. Comparison of the two tetrameric TgPK1 structures indicates a reorientation of the monomers with a concomitant change in the buried surface among adjacent monomers. The change in the buried surface was associated with significant B domain movements in one of the interacting monomers. We hypothesize that a loop in the interface between the A and B domains plays an important role linking the position of the B domain to the buried surface among monomers through two {alpha}-helices. The proposed model links the catalytic cycle of the enzyme with its domain movements and highlights the contribution of the interface between adjacent subunits. In addition, an unusual ordered conformation was observed in one of the allosteric binding domains and it is related to a specific apicomplexan insertion. The sequence and structural particularity would explain the atypical activation by a mono-phosphorylated sugar. The sum of peculiarities raises this enzyme as an emerging target for drug discovery.

  12. Long-term humoral antibody responses by various serologic tests in pigs orally inoculated with oocysts of four strains of Toxoplasma gondii

    DEFF Research Database (Denmark)

    Dubey, J.P.; Andrews, C.D.; Thulliez, P.

    1997-01-01

    Antibody titers to Toxoplasma gondii were determined in 16 pigs orally inoculated with 1000 or 10000 oocysts of one of the four strains (GT-1, ME-49, TS-2, TC-2) of T. gondii. Pigs were euthanized on postinoculation days 103-875 and their tissues were bioassayed for T. gondii. Antibody titers wer...

  13. Prevalence and genotyping ofToxoplasma gondii among Saudi pregnant women in Saudi Arabia.

    Science.gov (United States)

    Alghamdi, Jawahir; Elamin, Maha Hussein; Alhabib, Samia

    2016-11-01

    Introduction: Toxoplasma gondii ( T. gondii ) is an intracellular protozoan that can infect all mammals, who serve as intermediate host. It causes congenital, neurological, eyes complications and mild or asymptomatic infections in humans. Purpose of this study: To investigate not only the prevalence of T. gondii , but also to find out its genotyping using multiple sequential molecular methods to predict exactly the precise genotyping of T. gondii among Saudi pregnant women. Methods: A cross-sectional study was conducted using multi-stage methods. Initial stage involved enrolment of 250 Saudi pregnant women from multi-centre healthcare and community based settings in the capital of Saudi Arabia Riyadh. The second stage was embracement of the laboratory investigation that included Enzyme immunoassay (ELISA), DNA extraction, PCR, nested-PCR assay, and genotyping of the seropositive cases. Results: 203 women agreed to take part in our study with a response rate of 81.2% (203/250). Using ELISA, we found that the prevalence of Toxoplasma gondii IgG and IgM antibodies was 32.5% and 6.4%, respectively. We found that 29 samples (80.6%) were of genotype II; however 7 samples (19.4%) were of genotype III. Conclusion: Defining the population structure of T. gondii from Saudi Arabia has important implications for transmission, immunogenicity, pathogenesis, and in planning preventive strategies. Relationship between such variation in structure and disease manifestation in pregnant women is still difficult to assess due to the role of host immune status and genetic background on the control of infection, and of other parasitic features such as the infecting dose or parasite stage. Our finding of the genotyping of T. gondii might facilitate and inform future studies on comparative genomics and identification of genes that control important biological phenotypes including pathogenesis and transmission among Saudi women.

  14. Lack of association between Toxoplasma gondii infection and occupational exposure to animals

    Science.gov (United States)

    Pacheco-Vega, Sandy Janet; Hernández-Tinoco, Jesús; Saldaña-Simental, Diana Elizabeth; Sánchez-Anguiano, Luis Francisco; Salcedo-Jáquez, Misael; Ramos-Nevárez, Agar; Liesenfeld, Oliver; Márquez-Conde, José Ángel; Cerrillo-Soto, Sandra Margarita; Martínez-Ramírez, Lucio; Guido-Arreola, Carlos Alberto

    2014-01-01

    The association of infection with Toxoplasma gondii and occupational exposure to animals has been scantly determined. We performed a case-control study with 200 subjects from Durango Province, Mexico, occupationally exposed to animals and 200 age- and gender-matched subjects without this occupation. Sera from all participants were analyzed for anti-T. gondii IgG and IgM antibodies using enzyme-linked immunoassays. The association of seroprevalence with sociodemographic, work, clinical, and behavioral characteristics in cases was determined. Cases and controls had similar frequencies of anti-T. gondii IgG antibodies (12/200: 6.0% and 11/200: 5.5%, respectively) (OR = 3.0; 95% CI: 0.12–73.64; P = 1.0). The frequency of sera with high (>150 IU/ml) levels of anti-T. gondii IgG antibodies was comparable among cases and controls (P = 0.61). Seroprevalence of anti-T. gondii IgM antibodies was similar in cases (4, 2.0%) than in controls (4, 2.0%) (P = 1.0). Multivariate analysis showed that seropositivity was associated with eating while working (OR = 7.14; 95% CI: 1.91–26.72; P = 0.003) and consumption of duck meat (OR = 5.43; 95% CI: 1.43–20.54; P = 0.01). No association between seropositivity to T. gondii and occupational exposure to animals was found. However, risk factors for infection found should be taken into account to reduce the exposure to T. gondii. PMID:25544890

  15. An experimental Toxoplasma gondii dose response challenge model to study therapeutic or vaccine efficacy in cats.

    Directory of Open Access Journals (Sweden)

    Jan B W J Cornelissen

    Full Text Available High numbers of Toxoplasma gondii oocysts in the environment are a risk factor to humans. The environmental contamination might be reduced by vaccinating the definitive host, cats. An experimental challenge model is necessary to quantitatively assess the efficacy of a vaccine or drug treatment. Previous studies have indicated that bradyzoites are highly infectious for cats. To infect cats, tissue cysts were isolated from the brains of mice infected with oocysts of T. gondii M4 strain, and bradyzoites were released by pepsin digestion. Free bradyzoites were counted and graded doses (1000, 100, 50, 10, and 250 intact tissue cysts were inoculated orally into three cats each. Oocysts shed by these five groups of cats were collected from faeces by flotation techniques, counted microscopically and estimated by real time PCR. Additionally, the number of T. gondii in heart, tongue and brains were estimated, and serology for anti T. gondii antibodies was performed. A Beta-Poisson dose-response model was used to estimate the infectivity of single bradyzoites and linear regression was used to determine the relation between inoculated dose and numbers of oocyst shed. We found that real time PCR was more sensitive than microscopic detection of oocysts, and oocysts were detected by PCR in faeces of cats fed 10 bradyzoites but by microscopic examination. Real time PCR may only detect fragments of T. gondii DNA without the presence of oocysts in low doses. Prevalence of tissue cysts of T. gondii in tongue, heart and brains, and anti T. gondii antibody concentrations were all found to depend on the inoculated bradyzoite dose. The combination of the experimental challenge model and the dose response analysis provides a suitable reference for quantifying the potential reduction in human health risk due to a treatment of domestic cats by vaccination or by therapeutic drug application.

  16. [Seroprevalence and risk factors of Toxoplasma gondii infection among pregnant women in Wuxi region].

    Science.gov (United States)

    Zhou, Jiao-jiao; Tao, Li-li

    2015-12-01

    To investigate the prevalence and risk factors of Toxoplasma gondii infection among pregnant women in Wuxi City of Jiangsu Province, so as to provide the evidence for developing the preventive and control interventions of T. gondii infection. The anti-Toxoplasma IgM and IgG antibodies were detected by using ELISA in the sera sampled from 3 014 pregnant women from 2011 to 2014, and the pregnant outcomes were followed up. The risk factors of T. gondii infection were identified with questionnaires. Among the 3 014 pregnant women, 215 cases were found positive to anti-Toxoplasma antibody (7.13%), including 49 cases positive to IgM antibody (49/215, 22.79%), and 166 cases positive to IgG antibody (166/215, 77.21%). The follow-up revealed that 46 T. gondii-infected pregnant women developed adverse pregnant outcomes (46/215, 21.40%), including 35 cases positive to IgM antibody (35/46, 76.09%) and 11 cases positive to IgG antibody (11/ 46, 23.9.1%). Of the 275 pregnant women without T. gondii infection, 7 cases were found to have adverse pregnant outcomes (2.55%) , which was significantly lower than that in T. gondii-infected pregnant women (P pregnant women, compared with the uninfected group (all P values pregnant outcomes among pregnant women. Reduction of close contact with animals, development of good diet and hygiene habits and monitoring of T. gondii infection during pregnancy are effective approaches to avoid the development of adverse pregnant outcomes.

  17. Clonal types of Toxoplasma gondii among immune compromised and immune competent individuals in Accra, Ghana.

    Science.gov (United States)

    Ayi, Irene; Kwofie, Kofi Dadzie; Blay, Emmanuel Awusah; Osei, Joseph Harold Nyarko; Frempong, Kwadwo Kyeremeh; Koku, Roberta; Ghansah, Anita; Lartey, Margaret; Suzuki, Takashi; Boakye, Daniel Adjei; Koram, Kwadwo Ansah; Ohta, Nobuo

    2016-06-01

    There are three major clonal lineages, types I, II, and III, of Toxoplasma gondii known to cause human toxoplasmosis worldwide. Toxoplasma gondii infections have, however, not been genotyped in Ghana. This study detected the clonal types infecting immune compromised and immune competent individuals in Accra, Ghana. Blood samples were obtained from 148 HIV seropositive pre-antiretroviral therapy individuals (0 ≤ CD4(+) T-cell count/μl blood ≤ 200) at the Fevers Unit and 149 HIV seronegative apparently healthy blood donors at the blood bank, all of the Korle-Bu Teaching Hospital. Genomic DNA was extracted and multilocus genotyping conducted by nested PCR-RFLP analysis using GRA6, SAG3, and BTUB gene markers. Among the HIV seropositive participants, 54.7% (81/148) were T. gondii DNA positive for any of the markers. Out of the 81, 42.0% (34) were positive for SAG3 only, 30.9% (25) for GRA6 only, 24.7% (20) for both SAG3 and GRA6, and 2.5% (2) for SAG3, GRA6, and BTUB. Overall, 93.8% of the positives were of clonal type II, 1.2% type I, while 4.9% (4) were atypical or mixed types (I and II). In the healthy blood donors, prevalence of T. gondii DNA positivity was 3.4% (5/149) by SAG3 and/or GRA6; among them, 60.0% (3/5) were type I, and the remaining 40.0%, type II. This study showed a relatively high prevalence of active T. gondii infections in immune compromised patients and low prevalence in immune competent individuals in Accra. Type II was highly prevalent. Detection of T. gondii in blood donors raises public health concerns and screening for T. gondii should be considered. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  18. Detection of Toxoplasma gondii in naturally infected domestic pigs in Northern Serbia.

    Science.gov (United States)

    Kuruca, Ljiljana; Klun, Ivana; Uzelac, Aleksandra; Nikolić, Aleksandra; Bobić, Branko; Simin, Stanislav; Lalošević, Vesna; Lalošević, Dušan; Djurković-Djaković, Olgica

    2017-11-01

    Insufficiently cooked pork is considered as an important source of human infection with Toxoplasma gondii. The aim of our study was to investigate the presence of T. gondii in pigs intended for human consumption from Northern Serbia. Blood and diaphragm samples were collected from 182 naturally infected market-weight pigs, originating from both commercial farms and smallholdings. Sera were examined using modified agglutination test (MAT), and diaphragms from seropositive, as well as from some MAT-negative pigs, were bioassayed in mice. In addition, digests were examined for the presence of T. gondii DNA using a real-time polymerase chain reaction (qPCR) which was targeted at the 529 bp repetitive element of the T. gondii genome. The overall seroprevalence of T. gondii in pigs was 17% (31/182), with no difference between pigs from large commercial farms (17.8%) and those raised on smallholdings (16.3%). However, the seroprevalence in farm pigs was largely influenced by the findings on a single farm, where all examined animals tested positive. Parasites and/or parasite DNA were detected in the tissues of 15 of the 45 (25 seropositive and 20 seronegative) animals examined by either direct method. Tissue cysts were isolated in eight bioassays and an additional bioassay was positive by serology; all nine were confirmed positive by qPCR. All positive bioassays originated from seropositive pigs, but no correlation was observed between isolation rate and antibody titer. T. gondii DNA was detected in diaphragm tissues of eight pigs, of which three were seronegative. The results of our study provide further evidence for pork as a source of human T. gondii infection.

  19. Vaccination with a DNA vaccine encoding Toxoplasma gondii ROP54 induces protective immunity against toxoplasmosis in mice.

    Science.gov (United States)

    Yang, Wen-Bin; Zhou, Dong-Hui; Zou, Yang; Chen, Kai; Liu, Qing; Wang, Jin-Lei; Zhu, Xing-Quan; Zhao, Guang-Hui

    2017-12-01

    Toxoplasma gondii is an obligatory intracellular protozoan, which infects most of the warm-blooded animals, causing serious public health problems and enormous economic losses worldwide. The rhoptry effector protein 54 (ROP54) has been indicated as a virulence factor that promotes Toxoplasma infection by modulating GBP2 loading onto parasite-containing vacuoles, which can modulate some aspects of the host immune response. In order to evaluate the immuno-protective value of ROP54, we constructed a eukaryotic recombinant plasmid expressing T. gondii ROP54 and intramuscularly immunized Kunming mice with this recombinant plasmid against acute and chronic toxoplasmosis. All mice immunized with pVAX-ROP54 elicited a high level of specific antibody responses, a significant increase of lymphocyte proliferation, and a significant level of Th1-type cytokines (IFN-γ, IL-2 and IL-12p70), in addition to an increased production of Th2-type cytokines (IL-4 and IL-10). These results demonstrated that pVAX-ROP54 induced significant cellular and humoral (Th1/Th2) immune responses, which extended the survival time (13.0±1.15days for pVAX-ROP54 vs 6.7±0.48days for pVAX I, 6.8±0.42days for PBS and 6.5±0.53 for blank control) and significantly reduced cyst burden (35.9% for pVAX-ROP54, 1% for pVAX I and 2% for PBS, compared with blank control) of immunized mice. These results indicate that the recombinant ROP54 plasmid can provide partial protection and might be a potential vaccine candidate against acute and chronic toxoplasmosis. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Seroepidemiology of infection with Toxoplasma gondii in workers occupationally exposed to water, sewage, and soil in Durango, Mexico

    Science.gov (United States)

    Water, sewage, and soil are potential sources of infection for Toxoplasma gondii. Therefore, we sought to determine the prevalence of T. gondii infection and associated characteristics in 61 plumbers, 203 construction workers, and 168 gardeners in Durango City, Mexico. Participants were tested for T...

  1. Seroprevalence of Toxoplasma gondii in wild marsupials and rodents from the Atlantic forest of Pernambuco State, Northeastern region, Brazil

    Science.gov (United States)

    Felids are important in the epidemiology of Toxoplasma gondii because they are the only hosts that can excrete the environmentally resistant oocysts in their feces. Cats are considered to acquire T. gondii infection in nature by ingesting tissues of small mammals and birds. Serum samples of feral 22...

  2. Diagnosis of pulmonary infection with Toxoplasma gondii in immunocompromised HIV-positive patients by real-time PCR

    DEFF Research Database (Denmark)

    Petersen, E.; Edvinsson, B.; Lundgren, Bettina

    2006-01-01

    The aim of the study presented here was to evaluate the use of PCR for improving the diagnosis of Toxoplasma gondii infection in immunocompromised hosts. Three hundred thirty-two bronchoalveolar lavage (BAL) fluid samples were analyzed by real-time PCR targeting a 529 bp element of T. gondii...

  3. Diagnosis of pulmonary infection with Toxoplasma gondii in immunocompromised HIV-positive patients by real-time PCR

    DEFF Research Database (Denmark)

    Petersen, E; Edvinsson, B; Lundgren, B

    2006-01-01

    The aim of the study presented here was to evaluate the use of PCR for improving the diagnosis of Toxoplasma gondii infection in immunocompromised hosts. Three hundred thirty-two bronchoalveolar lavage (BAL) fluid samples were analyzed by real-time PCR targeting a 529 bp element of T. gondii. In ...

  4. Toxoplasmosis in geese and detection of two new atypical Toxoplasma gondii strains from naturally infected Canada geese (Branta canadensis)

    Science.gov (United States)

    The protozoan Toxoplasma gondii infects virtually all warm-blooded animals, including birds, humans, livestock, and marine mammals. The consumption of raw or undercooked meat infected with T. gondii is considered an important source of infection in humans. Canada goose (Branta canadensis), the most ...

  5. Latitudinal variability in the seroprevalence of antibodies against Toxoplasma gondii in non-migrant and Arctic migratory geese

    NARCIS (Netherlands)

    Sandstrom, Cecilia A. M.; Buma, Anita G. J.; Hoye, Bethany J.; Prop, Jouke; van der Jeugd, Henk; Voslamber, Berend; Madsen, Jesper; Loonen, Maarten J. J. E.

    2013-01-01

    Toxoplasma gondii is an intracellular coccidian parasite found worldwide and is known to infect virtually all warm-blooded animals. It requires a cat (family Felidae) to complete its full life cycle. Despite the absence of wild felids on the Arctic archipelago of Svalbard, T. gondii has been found

  6. Toxoplasma gondii inhibits cytochrome c-induced caspase activation in its host cell by interference with holo-apoptosome assembly

    Directory of Open Access Journals (Sweden)

    Kristin Graumann

    2015-05-01

    Full Text Available Inhibition of programmed cell death pathways of mammalian cells often facilitates the sustained survival of intracellular microorganisms. The apicomplexan parasite Toxoplasma gondii is a master regulator of host cell apoptotic pathways. Here, we have characterized a novel anti-apoptotic activity of T. gondii. Using a cell-free cytosolic extract model, we show that T. gondii interferes with the activities of caspase 9 and caspase 3/7 which have been induced by exogenous cytochrome c and dATP. Proteolytic cleavage of caspases 9 and 3 is also diminished suggesting inhibition of holo-apoptosome function. Parasite infection of Jurkat T cells and subsequent triggering of apoptosome formation by exogenous cytochrome c in vitro and in vivo indicated that T. gondii also interferes with caspase activation in infected cells. Importantly, parasite inhibition of cytochrome c-induced caspase activation considerably contributes to the overall anti-apoptotic activity of T. gondii as observed in staurosporine-treated cells. Co-immunoprecipitation showed that T. gondii abolishes binding of caspase 9 to Apaf-1 whereas the interaction of cytochrome c with Apaf-1 remains unchanged. Finally, T. gondii lysate mimics the effect of viable parasites and prevents holo-apoptosome functionality in a reconstituted in vitro system comprising recombinant Apaf-1 and caspase 9. Beside inhibition of cytochrome c release from host cell mitochondria, T. gondii thus also targets the holo-apoptosome assembly as a second mean to efficiently inhibit the caspase-dependent intrinsic cell death pathway.

  7. Seroprevalence, isolation, and co-infection of multiple Toxoplasma gondii strains in individual bobcats (Lynx rufus) from Mississippi, USA

    Science.gov (United States)

    Toxoplasma gondii causes lifelong chronic infection in both feline definitive hosts and intermediate hosts. Multiple exposures of the parasite are likely to occur in nature because of high environmental contamination. Here, we present data of high seroprevalence and multiple T. gondii strain co-infe...

  8. Seroprevalence and Risk Factors of Toxoplasma gondii Infection in Farmed Minks (Neovison vison) in Northeastern and Eastern China.

    Science.gov (United States)

    Zheng, Wen-Bin; Cong, Wei; Meng, Qing-Feng; Ma, Jian-Gang; Wang, Chun-Feng; Zhu, Xing-Quan; Qian, Ai-Dong

    2016-07-01

    Toxoplasma gondii is an important intracellular parasite, which can infect endothermic vertebrate animals, including minks (Neovison vison). However, information on T. gondii infection in minks in China is limited. Therefore, we investigated the seroprevalence and risk factors of T. gondii infection in minks in northeastern and eastern China. A total of 1499 mink blood samples were randomly collected from eight cities between March 2014 and January 2015 in northeastern and eastern China, and antibodies to T. gondii were examined using the modified agglutination test. Overall, the seroprevalence of T. gondii infection was 8.14% in the examined minks. The T. gondii seroprevalence was different among cities (ranging from 1.85% in Changchun to 15.75% in Dalian), genders (4.31% in male and 6.22% in female), seasons (spring: 11.64%; summer: 7.34%; autumn: 7.37%; and winter: 7.32%), and ages (young: 5.79%; subadult: 5.03%; and adult: 11.08%). Region and age were considered as risk factors for T. gondii infection. These results provided baseline data for the prevention and control of T. gondii infection in minks in China.

  9. Molecular Detection and Genetic Characterization of Toxoplasma gondii in Farmed Minks (Neovison vison in Northern China by PCR-RFLP.

    Directory of Open Access Journals (Sweden)

    Wen-Bin Zheng

    Full Text Available Toxoplasma gondii is a worldwide prevalent parasite, affecting a wide range of mammals and human beings. Little information is available about the distribution of genetic diversity of T. gondii infection in minks (Neovison vison. This study was conducted to estimate the prevalence and genetic characterization of T. gondii isolates from minks in China. A total of 418 minks brain tissue samples were collected from Jilin and Hebei provinces, northern China. Genomic DNA were extracted and assayed for T. gondii infection by semi-nested PCR of B1 gene. The positive DNA samples were typed at 10 genetic markers (SAG1, SAG2 (5'+3' SAG2, alter.SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP technology. 36 (8.6% of 418 DNA samples were overall positive for T. gondii. Among them, 5 samples were genotyped at all loci, and 1 sample was genotyped for 9 loci. In total, five samples belong to ToxoDB PCR-RFLP genotype#9, one belong to ToxoDB genotye#3. To our knowledge, this is the first report of genetic characterization of T. gondii in minks in China. Meanwhile, these results revealed a distribution of T. gondii infection in minks in China. These data provided base-line information for controlling T. gondii infection in minks.

  10. Molecular Detection and Genetic Characterization of Toxoplasma gondii in Farmed Minks (Neovison vison) in Northern China by PCR-RFLP.

    Science.gov (United States)

    Zheng, Wen-Bin; Zhang, Xiao-Xuan; Ma, Jian-Gang; Li, Fa-Cai; Zhao, Quan; Huang, Si-Yang; Zhu, Xing-Quan

    2016-01-01

    Toxoplasma gondii is a worldwide prevalent parasite, affecting a wide range of mammals and human beings. Little information is available about the distribution of genetic diversity of T. gondii infection in minks (Neovison vison). This study was conducted to estimate the prevalence and genetic characterization of T. gondii isolates from minks in China. A total of 418 minks brain tissue samples were collected from Jilin and Hebei provinces, northern China. Genomic DNA were extracted and assayed for T. gondii infection by semi-nested PCR of B1 gene. The positive DNA samples were typed at 10 genetic markers (SAG1, SAG2 (5'+3' SAG2, alter.SAG2), SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico) using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technology. 36 (8.6%) of 418 DNA samples were overall positive for T. gondii. Among them, 5 samples were genotyped at all loci, and 1 sample was genotyped for 9 loci. In total, five samples belong to ToxoDB PCR-RFLP genotype#9, one belong to ToxoDB genotye#3. To our knowledge, this is the first report of genetic characterization of T. gondii in minks in China. Meanwhile, these results revealed a distribution of T. gondii infection in minks in China. These data provided base-line information for controlling T. gondii infection in minks.

  11. Seroprevalence of Toxoplasma gondii and Neospora caninum in feral cats (Felis silvestris catus) in Majorca, Balearic Islands, Spain

    Science.gov (United States)

    Felids are important in the epidemiology of Toxoplasma gondii infection because they are the only hosts that can excrete environmentally-resistant oocysts. Antibodies to T. gondii and Neospora caninum were determined in serum samples from 59 feral cats (Felis silvestris catus) captured in baited tra...

  12. Quantifying the risk of human Toxoplasma gondii infection due to consumption of domestically-produced lamb in the United States

    Science.gov (United States)

    Toxoplasma gondii is a widely prevalent protozoan parasite worldwide. Human toxoplasmosis is responsible for considerable morbidity and mortality in the United States. Meat products have been identified as an important source of T. gondii infections in humans. The goal of this study was to develop a...

  13. Isolation and genetic characterization of Toxoplasma gondii from naturally infected Canada goose (Branta canadensis) detected two new atypical strains

    Science.gov (United States)

    Wild birds are important in the epidemiology of toxoplasmosis because they can serve as reservoir hosts, and vectors of zoonotic pathogens including Toxoplasma gondii. Canada goose (Branta canadensis) is the most widespread goose in North America. Little is known concerning T. gondii infection in bo...

  14. Aborto espontâneo e toxoplasmose ocular em um casal infectado com Toxoplasma gondii = Spontaneous abortion and ocular toxoplasmosis in a couple infected with Toxoplasma gondii

    Directory of Open Access Journals (Sweden)

    Souza, Carla Zangari de

    2015-01-01

    Full Text Available Objetivos: Relatar os casos de um casal, em que a esposa apresentou toxoplasmose na gestação e o esposo, após 15 anos, foi diagnosticado com toxoplasmose ocular. Relato dos casos: Gestante, grávida de gêmeos, residente de um estado na região Sul do Brasil. No primeiro mês de gestação apresentou sorologia não reagente para IgG e IgM anti-Toxoplasma gondii. Na sétima semana de gestação houve soroconversão (IgM e IgG anti-T. gondii reagentes e aborto natural. O esposo, após 15 anos desde o episódio da esposa, queixou-se de visão embaçada/irritada. O exame de fundoscopia revelou lesões típicas de coriorretinite recidivante por toxoplasmose no olho direito. Os exames sorológicos foram IgG anti-T. gondii reagente e IgM anti-T. gondii não reagente. Conclusões: Este relato, de um casal com desfechos clínicos importantes de toxoplasmose, em diferentes formas, enfatiza a relevância do problema da toxoplasmose, que nas suas diversas manifestações, pode trazer graves consequências para a vida de uma família

  15. Characterisation of Toxoplasma gondii isolates using polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) of the non-coding Toxoplasma gondii (TGR)-gene sequences

    DEFF Research Database (Denmark)

    Høgdall, Estrid; Vuust, Jens; Lind, Peter

    2000-01-01

    of using TGR gene variants as markers to distinguish among T. gondii isolates from different animals and different geographical sources. Based on the band patterns obtained by restriction fragment length polymorphism (RFLP) analysis of the polymerase chain reaction (PCR) amplified TGR sequences, the T...

  16. Toxoplasma gondii seroprevalence in donkeys (Equus asinus) from the U.S.A. and isolation of T. gondii from cats on donkey farms

    Science.gov (United States)

    Donkeys (Equus asinus) are used as companion animals, in leisure activities as working animals, for onotherapy, and their meat and milk is used for human consumption in certain countries. Here we report first serological survey for Toxoplasma gondii in donkeys in the U.S.A. Serum samples were collec...

  17. Coordinated progression through two subtranscriptomes underlies the tachyzoite cycle of Toxoplasma gondii.

    Directory of Open Access Journals (Sweden)

    Michael S Behnke

    2010-08-01

    Full Text Available Apicomplexan parasites replicate by varied and unusual processes where the typically eukaryotic expansion of cellular components and chromosome cycle are coordinated with the biosynthesis of parasite-specific structures essential for transmission.Here we describe the global cell cycle transcriptome of the tachyzoite stage of Toxoplasma gondii. In dividing tachyzoites, more than a third of the mRNAs exhibit significant cyclical profiles whose timing correlates with biosynthetic events that unfold during daughter parasite formation. These 2,833 mRNAs have a bimodal organization with peak expression occurring in one of two transcriptional waves that are bounded by the transition into S phase and cell cycle exit following cytokinesis. The G1-subtranscriptome is enriched for genes required for basal biosynthetic and metabolic functions, similar to most eukaryotes, while the S/M-subtranscriptome is characterized by the uniquely apicomplexan requirements of parasite maturation, development of specialized organelles, and egress of infectious daughter cells. Two dozen AP2 transcription factors form a series through the tachyzoite cycle with successive sharp peaks of protein expression in the same timeframes as their mRNA patterns, indicating that the mechanisms responsible for the timing of protein delivery might be mediated by AP2 domains with different promoter recognition specificities.Underlying each of the major events in apicomplexan cell cycles, and many more subordinate actions, are dynamic changes in parasite gene expression. The mechanisms responsible for cyclical gene expression timing are likely crucial to the efficiency of parasite replication and may provide new avenues for interfering with parasite growth.

  18. Toxoplasma gondii Infections Alter GABAergic Synapses and Signaling in the Central Nervous System

    Science.gov (United States)

    Brooks, Justin M.; Carrillo, Gabriela L.; Su, Jianmin; Lindsay, David S.; Blader, Ira J.

    2015-01-01

    ABSTRACT During infections with the protozoan parasite Toxoplasma gondii, gamma-aminobutyric acid (GABA) is utilized as a carbon source for parasite metabolism and also to facilitate parasite dissemination by stimulating dendritic-cell motility. The best-recognized function for GABA, however, is its role in the nervous system as an inhibitory neurotransmitter that regulates the flow and timing of excitatory neurotransmission. When this pathway is altered, seizures develop. Human toxoplasmosis patients suffer from seizures, suggesting that Toxoplasma interferes with GABA signaling in the brain. Here, we show that while excitatory glutamatergic presynaptic proteins appeared normal, infection with type II ME49 Toxoplasma tissue cysts led to global changes in the distribution of glutamic acid decarboxylase 67 (GAD67), a key enzyme that catalyzes GABA synthesis in the brain. Alterations in GAD67 staining were not due to decreased expression but rather to a change from GAD67 clustering at presynaptic termini to a more diffuse localization throughout the neuropil. Consistent with a loss of GAD67 from the synaptic terminals, Toxoplasma-infected mice develop spontaneous seizures and are more susceptible to drugs that induce seizures by antagonizing GABA receptors. Interestingly, GABAergic protein mislocalization and the response to seizure-inducing drugs were observed in mice infected with type II ME49 but not type III CEP strain parasites, indicating a role for a polymorphic parasite factor(s) in regulating GABAergic synapses. Taken together, these data support a model in which seizures and other neurological complications seen in Toxoplasma-infected individuals are due, at least in part, to changes in GABAergic signaling. PMID:26507232

  19. Involvement of Toxoplasma gondii in reproductive disorders in Swiss pig farms.

    Science.gov (United States)

    Basso, Walter; Handke, Martin; Sydler, Titus; Borel, Nicole; Grimm, Felix; Sidler, Xaver; Deplazes, Peter

    2015-04-01

    To determine the role of Toxoplasma gondii in reproductive failure, 108 of 113 sows that had aborted or delivered stillborn or weak piglets from 58 Swiss farms were serologically tested for specific antibodies against T. gondii tachyzoite antigens by ELISA. Additionally, formalin-fixed and paraffin-embedded tissues from 123 foetuses or stillborn piglets derived from 25 seropositive and 27 seronegative sows were analyzed by real-time PCR for T. gondii DNA. Tissues from animals showing a positive reaction in real-time PCR were subsequently tested by immunohistochemistry for the presence of T. gondii antigens. Antibodies against T. gondii were detected in 24.1% (26 out of 108) of sows with reproductive failure, and 37.3% (22 of 58) of the 58 tested farms had seropositive sows. No significant differences in the prevalences were observed in relation to the housing system (exclusive indoor housing, indoor housing with outdoor yard and exclusive outdoor housing) neither at the individual nor at the farm levels. By real time-PCR, T. gondii DNA was detected in three placentas from one seropositive sow (abortion at 71 gestation days [gd]), and in brain tissues from one foetus (abortion at 76 gd), one stillborn (116 gd) and one mummy (112 gd) delivered by three further seropositive sows, but in no sample derived from seronegative dams. By immunohistochemical staining, the presence of T. gondii could be confirmed only in placenta samples. In one of the cases, a co-infection with porcine parvovirus (PPV) was detected. These results suggest vertical transmission of T. gondii and/or placental infection in at least 3.5% (4 of 113) of sows with reproductive disorders. Therefore, T. gondii should be more frequently included in the routine differential diagnosis of reproductive failure in sows. In addition, a proper disposal of placentas and abortion material beyond the reach of cats could help to interrupt the further dissemination of this parasite at the farm level. Copyright

  20. Occurrence of antibodies to Toxoplasma gondii in rheas (Rhea americana and ostriches (Struthio camelus from farms of different Brazilian regions

    Directory of Open Access Journals (Sweden)

    Amanda Brentano Almeida

    Full Text Available This study aimed to verify the occurrence of antibodies againstToxoplasma gondii in rheas (Rhea americana and ostriches (Struthio camelus commercially breeding in Brazil. Blood samples from 20 rheas and 46 ostriches (young and adults were serologically tested using a technique known as modified agglutination test (MAT at an initial titration of 1:16 for ostriches and 1:25 for rheas. Antibodies against T. gondii were found in 50% (10/20 of the rheas, with titers ranging from 1:25 to 1:6,400. The incidence of antibodies against T. gondii in ostriches was 17.4% (8/46 with titers ranging from 1:16 to 1:256. Birds showing titers higher than 1:200 forT. gondii were mainly the young ones. Therefore, rheas and ostriches may be parasitized by T. gondii, showing high levels of antibodies against this parasite.

  1. Seroprevalence of Toxoplasma gondii in wild boars, red deer and roe deer in Poland.

    Science.gov (United States)

    Witkowski, Lucjan; Czopowicz, Michał; Nagy, Dan Alexandru; Potarniche, Adrian Valentin; Aoanei, Monica Adriana; Imomov, Nuriddin; Mickiewicz, Marcin; Welz, Mirosław; Szaluś-Jordanow, Olga; Kaba, Jarosław

    2015-01-01

    Little is known about the prevalence of Toxoplasma gondii in wild life, particularly game animals in Poland. Meat juice collected during the 2009/2010 and 2010/2011 hunting seasons from 552 red deer (Cervus elaphus), 367 wild boars (Sus scrofa) and 92 roe deer (Capreolus capreolus) was tested for T. gondii antibodies using the multi-species ID Screen Toxoplasmosis Indirect kit (IDvet, Montpellier, France). Antibodies to T. gondii were detected in 24.1% of red deer (95% CI: 20.7%, 27.8%), 37.6% of wild boar (95% CI: 32.8%, 42.7%) and 30.4% of roe deer (95% CI: 22.0%, 40.5%). To the authors' best knowledge, this is the first epidemiological report of T. gondii prevalence in red deer, roe deer and wild boars in Poland. T. gondii is present in wildlife animal tissues and consumption of the game may be a potential source of infection for humans. © L. Witkowski et al., published by EDP Sciences, 2015.

  2. Toxoplasma gondii Myocarditis after Adult Heart Transplantation: Successful Prophylaxis with Pyrimethamine

    Science.gov (United States)

    Strabelli, Tania Mara V.; Siciliano, Rinaldo Focaccia; Vidal Campos, Silvia; Bianchi Castelli, Jussara; Bacal, Fernando; Bocchi, Edimar A.; Uip, David E.

    2012-01-01

    Toxoplasma gondii primary infection/reactivation after solid organ transplantation is a serious complication, due to the high mortality rate following disseminated disease. We performed a retrospective study of all cases of T. gondii infections in 436 adult patients who had received an orthotopic cardiac transplant at our Institution from May 1968 to January 2011. Six patients (1.3%) developed T. gondii infection/reactivation in the post-operative period. All infections/reactivations occurred before 1996, when no standardized toxoplasmosis prophylactic regimen or co-trimoxazole prophylaxis was used. Starting with the 112th heart transplant, oral pyrimethamine 75 mg/day was used for seronegative transplant recipients whose donors were seropositive or unknown. Two patients (33.3%) presented with disseminated toxoplasmosis infection, and all patients (100%) had myocarditis. Five patients (83.3%) were seronegative before transplant and one patient did not have pre-transplant serology available. Median time for infection onset was 131 days following transplantation. Three patients (50%) died due to toxoplasmosis infection. After 1996, we did not observe any additional cases of T. gondii infection/reactivation. In conclusion, toxoplasmosis in heart allographs was more frequent among seronegative heart recipients, and oral pyrimethamine was highly effective for the prevention of T. gondii infection in this population. PMID:23209479

  3. Occurrence of Toxoplasma gondii antibodies in lowland tapirs maintained ex situ in Brazil and Paraguay

    Directory of Open Access Journals (Sweden)

    Maria Fernanda Naegeli Gondim

    Full Text Available ABSTRACT: Lowland Tapir ( Tapirus terrestris is the second largest South American land mammal. It is strictly herbivorous and its exposure to Toxoplasma gondii should be indicative of environmental contamination by oocysts.In the present study antibodies to T. gondii in 47 Brazilian tapirs maintained ex situ in 10 Brazilian and in one Paraguayan institution were sought in serum samples by the modified agglutination test (MAT ≥25. None of the animals presented clinical signs during the study. From 47 animals 35 (74.5% were positive with titers of 25 in 8, 50 in 6, 100 in 12, 200 in 5, 400 in 1 and 800 in 3. One animal had samples collected on twice, and 19 were born in captivity. There was no association between occurrence of T. gondii antibodies and gender, and positive animals were reported in all institutions. The high occurrence of seropositive tapirs born ininstitutions (54.3% confirmed the high exposure of these mammals to T. gondii in captivity. Only two cases ofabortion were reported, but it was not possible to correlate these abortions to T. gondii infection.

  4. Seroprevalence of Toxoplasma gondii in wild boars, red deer and roe deer in Poland

    Directory of Open Access Journals (Sweden)

    Witkowski Lucjan

    2015-01-01

    Full Text Available Little is known about the prevalence of Toxoplasma gondii in wild life, particularly game animals in Poland. Meat juice collected during the 2009/2010 and 2010/2011 hunting seasons from 552 red deer (Cervus elaphus, 367 wild boars (Sus scrofa and 92 roe deer (Capreolus capreolus was tested for T. gondii antibodies using the multi-species ID Screen Toxoplasmosis Indirect kit (IDvet, Montpellier, France. Antibodies to T. gondii were detected in 24.1% of red deer (95% CI: 20.7%, 27.8%, 37.6% of wild boar (95% CI: 32.8%, 42.7% and 30.4% of roe deer (95% CI: 22.0%, 40.5%. To the authors’ best knowledge, this is the first epidemiological report of T. gondii prevalence in red deer, roe deer and wild boars in Poland. T. gondii is present in wildlife animal tissues and consumption of the game may be a potential source of infection for humans.

  5. Toxoplasma gondii exposes phosphatidylserine inducing a TGF-β1 autocrine effect orchestrating macrophage evasion

    International Nuclear Information System (INIS)

    Seabra, Sergio H.; Souza, Wanderley de; Matta, Renato A. da

    2004-01-01

    Toxoplasmosis is a worldwide disease caused by Toxoplasma gondii. Activated macrophages control T. gondii growth by nitric oxide (NO) production. However, T. gondii active invasion inhibits NO production, allowing parasite persistence. Here we show that the mechanism used by T. gondii to inhibit NO production persisting in activated macrophages depends on phosphatidylserine (PS) exposure. Masking PS with annexin-V on parasites or activated macrophages abolished NO production inhibition and parasite persistence. NO production inhibition depended on a transforming growth factor-β 1 (TGF-β 1 ) autocrine effect confirmed by the expression of Smad 2 and 3 in infected macrophages. TGF-β 1 led to inducible nitric oxide synthase (iNOS) degradation, actin filament (F-actin) depolymerization, and lack of nuclear factor-κB (NF-κB) in the nucleus. All these features were reverted by TGF-β 1 neutralizing antibody treatment. Thus, T. gondii mimics the evasion mechanism used by Leishmania amazonensis and also the anti-inflammatory response evoked by apoptotic cells

  6. Detection of anti-Toxoplasma gondii antibodies in chronic myeloid leukemia and acute myeloid leukemia patients

    Directory of Open Access Journals (Sweden)

    Mohammad Javad Gharavi

    2017-09-01

    Full Text Available Background and Aim: Infection of Toxoplasma gondii is a worldwide distribution. Toxoplasmosis in patients who are immunocompromised by virtue of underlying leukemia disease has received relatively little attention. This study was aimed to evaluate IgG and IgM antibodies of T. gondii and to minimize the role of T. gondii and opportunistic infection complication at the early stage of infection in leukemia patients. Materials and Methods: The purpose of this assay was to measure anti-T. gondii IgG and IgM antibodies by enzyme-linked immunosorbent assay (ELISA technique in leukemia patients. Results: IgG antibodies against T. gondii were detected by ELISA in 96 (56.4% leukemia patients and 72 (42.4% control group. IgM antibodies were found in 10 patients (5.9% with leukemia and 3 (1.8% in the corresponding. Conclusion: Our finding indicated that leukemia patients under immunosuppressive condition should not be neglected. Toxoplasmosis in leukemia patients as a main risk factor is considered, meanwhile in some patients, due to possibility of the presence of secondary infection that leads to severe toxoplasmosis.

  7. Portugal and Angola: similarities and differences in Toxoplasma gondii seroprevalence and risk factors in pregnant women.

    Science.gov (United States)

    Lobo, M L; Patrocinio, G; Sevivas, T; DE Sousa, B; Matos, O

    2017-01-01

    In this study we determined the presence of IgM/IgG antibodies to Toxoplasma gondii in sera of 155 and 300 pregnant women from Lisbon (Portugal) and Luanda (Angola), respectively, and evaluated the potential risk factors associated with this infection. DNA detection was performed by PCR assays targeting T. gondii regions (RE/B1). Overall, 21·9% (10·9% IgG, 10·9% IgG/IgM) of the Lisbon women and 27·3% (23·7%, IgG, 2% IgM, 1·7% IgG/IgM) of the Luanda women had antibodies to T. gondii. Single variable and binary logistic regression analyses were conducted. Based on the latter, contacts with cats (family/friends), and having more than two births were identified as risk factors for Toxoplasma infection in Lisbon women. In Luanda, the risk factors for T. gondii infection suggested by the single variable analysis (outdoor contact with cats and consumption of pasteurized milk/dairy products) were not confirmed by binary logistic regression. This study shows original data from Angola, and updated data from Portugal in the study of infection by T. gondii in pregnant women, indicating that the prevalence of anti-Toxoplasma antibodies is high enough to alert the government health authorities and implement appropriate measures to control this infection.

  8. Toxoplasma gondii and Neospora caninum infections in goat abortions from Argentina.

    Science.gov (United States)

    Unzaga, J M; Moré, G; Bacigalupe, D; Rambeaud, M; Pardini, L; Dellarupe, A; De Felice, L; Gos, M L; Venturini, M C

    2014-12-01

    The aims of this study were to identify the occurrence of Toxoplasma gondii and Neospora caninum abortions in goats from Argentina by serological, macroscopical and microscopical examination and bioassay, and to characterize the obtained isolates by molecular techniques. For this purpose, 25 caprine fetal fluids, 18 caprine fetal brains and 10 caprine placentas from 8 dairy/meat goat farms from Argentina were analyzed. Gestational age of the aborted fetuses was determined in 18 cases. Protozoal infections were detected by at least one of the applied diagnostic techniques in 44% (11/25) of examined fetuses; specifically, 24% (6/25) were positive to T. gondii, 8% (2/25) were positive to N. caninum and 12% (3/25) were positive to both parasites. In this study IFAT titers were similarly distributed in younger and older fetuses. Macroscopical and microscopical examination of one placenta revealed chalky nodules in the fetal cotyledons and normal intercotyledonary areas, as well as necrosis and calcification of mesenchymal cells in villi. Tachyzoites were observed in peritoneal wash from 2 mice inoculated with brain and a pool of brain and placenta of two fetuses. Cell culture growth of tachyzoites was achieved from one inoculated mouse, and confirmed as T. gondii by PCR. The T. gondii isolate was identified as atypical or non-canonical by nested-PCR-RFLP. This is the first study that investigated the involvement of N. caninum and T. gondii in cases of goat abortion in Argentina. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  9. Seroprevalence of Neospora caninum and Toxoplasma gondii in exotic ruminants and camelids in the Czech Republic.

    Science.gov (United States)

    Bártová, Eva; Kobédová, Kateřina; Lamka, Jiří; Kotrba, Radim; Vodička, Roman; Sedlák, Kamil

    2017-07-01

    Neospora caninum and Toxoplasma gondii are the protozoan parasites with definitive hosts from order Carnivora. Due to vertical transmission, both parasites can cause abortions and neonatal mortality that lead to significant productive and economic losses in the domestic ruminants. The aim of this study was to describe N. caninum and T. gondii seroprevalence in the group of frequently farmed captive exotic ruminants (n = 184) including Bovidae (barbary sheep, bezoar goat, common eland, American bison, water buffalo, and yak) and Camelidae (bactrian camel, guanaco, llama, and alpaca). Antibodies were tested by indirect fluorescent antibody test (IFAT) and enzyme-linked immunosorbent assay (ELISA). Higher prevalence of T. gondii antibodies (31% in IFAT and 52% in ELISA) was detected compared to N. caninum (24% in IFAT and 17% in cELISA). Mixed infection was found in 18 (10%) and 22 (12%) animals by IFAT and ELISA, respectively. Higher seroprevalence of both N. caninum and T. gondii was found in Camelidae compared to Bovidae. To author knowledge, this is the first detection of T. gondii and N. caninum antibodies in common elands and bezoar goats.

  10. Association between Toxoplasma gondii types and outcomes of human infection: A meta-analysis.

    Science.gov (United States)

    Xia, Jing; Cheng, Xin-Yu; Wang, Xiao-Jun; Peng, Hong-Juan

    2017-09-01

    The virulence and pathogenicity of various types of Toxoplasma gondii differ considerably in mice. Recent studies have claimed that similar phenomenon was observed in humans, but no relevant studies have been performed to validate this finding. In addition, reports showing association between a given T. gondii type and outcomes of human infection yielded conflicting results. To provide a more precise estimation of the association and a more reliable conclusion on this subject, we performed this meta-analysis. Relevant literatures were identified in multiple databases and selected based on strict screening. T. gondii-type proportions among different severities of infection were calculated and compared using Fisher's exact test. Pooled odds ratios (OR) were calculated. Our results showed that the difference among T. gondii-type proportions was significant (p < 0.0001). In addition, significant associations were detected between Type I strains infection and congenital toxoplasmosis (OR: 1.91, p = 0.0009), Type III strains infection and pulmonary toxoplasmosis (OR: 5.15, p = 0.04). In our subgroup analysis, Type I strains were significantly associated with cerebral toxoplasmosis in offspring (OR: 1.81, p = 0.02). This result indicated that different types of T. gondii exhibited different virulence and caused different outcomes in humans.

  11. Prevalence of Toxoplasma gondii infection in HIV-infected patients and food animals and direct genotyping of T. gondii isolates, Southern Ghana.

    Science.gov (United States)

    Pappoe, Faustina; Cheng, Weisheng; Wang, Lin; Li, Yuanling; Obiri-Yeboah, Dorcas; Nuvor, Samuel Victor; Ambachew, Henock; Hu, Xiaodong; Luo, Qingli; Chu, Deyong; Xu, Yuanhong; Shen, Jilong

    2017-06-01

    Toxoplasma gondii is of public health and veterinary importance causing severe diseases in immunocompromised individuals including HIV/AIDS patients and in congenital cases and animals. There is limited information on the epidemiology of T. gondii infection in humans, particularly HIV patients and food animals and the parasite genotypes in Ghana. A total of 394 HIV-infected patients from three hospitals were screened for T. gondii anti-IgG and IgM using ELISA. DNAs from blood samples of seropositve participants and 95 brain tissues of food animals were PCR assayed to detect Toxoplasma gra6. DNA positive samples were genotyped using multilocus nested polymerase chain reaction restriction fragment length polymorphism at 10 loci: sag1, alt.sag2, sag3, btub, gra6, l358, c22-8, c29-2, pk1, and apico. The overall seroprevalence was 74.37% (293/394). Toxoplasma DNAs were detected in 3.07% of the seropositive participants and 9.47% of the animals. Six of the human DNA positive samples were partly typed at sag3: 33.33, 50, and 16.67% isolates had type I, II, and III alleles, respectively. All nine isolates from food animals typed at nine loci except apico were atypical: six isolates were identical to ToxoDB #41 and #145, and one was identical to TgCkBrRj2 all identified in Brazil. The genotype of two isolates has not been reported previously and was named as TgCtGh1. T. gondii seroprevalence is high among the HIV-infected individuals with T. gondii circulating in Ghana being genetically diverse.

  12. Reciprocal moderation by Toxoplasma gondii seropositivity and blood phenylalanine – tyrosine ratio of their associations with trait aggression

    Science.gov (United States)

    Mathai, Ashwin Jacob; Lowry, Christopher A.; Cook, Thomas B.; Brenner, Lisa A.; Brundin, Lena; Groer, Maureen W.; Peng, Xiaoqing; Giegling, Ina; Hartmann, Annette M.; Konte, Bettina; Friedl, Marion; Fuchs, Dietmar; Rujescu, Dan

    2017-01-01

    We previously reported that trait aggression, proposed as an endophenotype for suicidal behavior, is positively associated with Toxoplasma gondii (T. gondii) seropositivity in females, but not in males. Additionally, older males seropositive for T. gondii had lower scores on measures of trait aggression, including self-aggression. Trait aggression may be influenced by dopaminergic signaling, which is known to be moderated by gender and age, and potentially enhanced in T. gondii positives through the intrinsic production of dopamine by the microorganism. Therefore, we investigated associations between trait aggression and interactions between T. gondii enzyme-linked immunoabsorbant assay (ELISA) IgG titer-determined seropositivity and high-performance liquid chromatography- (HPLC-) measured blood levels of dopamine precursors phenylalanine (Phe), tyrosine (Tyr), and their ratio in a sample of 1000 psychiatrically healthy participants. Aggressive traits were assessed using the questionnaire for measuring factors of aggression (FAF), the German version of the Buss-Durkee hostility questionnaire. We found that 1) the decrease in trait aggression scores in T. gondii-positive older males was only present in individuals with a low Phe:Tyr ratio, and 2) that there was a positive correlation between Phe:Tyr ratio and total aggression and selected subscales of aggression in T. gondii-positive males, but not in T. gondii-negative males. These findings point toward a gender-specific reciprocal moderation by Phe:Tyr ratio and T. gondii seropositivity of their associations with aggression scores, and lead to experimental interventions geared to manipulating levels of dopamine precursors in selected T. gondii positive individuals with increased propensity for aggression. PMID:28943719

  13. Toxoplasma gondii Infection Suppresses House Dust Mite Extract-Induced Atopic Dermatitis in NC/Nga Mice.

    Science.gov (United States)

    Jeong, Young Il; Hong, Sung Hee; Cho, Shin Hyeong; Lee, Won Ja; Lee, Sang Eun

    2015-11-01

    Toxoplasma gondii (T. gondii) is an obligate intracellular protozoan parasite that infects humans and animals via congenital or postnatal routes, and it is found worldwide. Modulation of the immune system by parasite infection is proposed to suppress allergic inflammation. Growing evidences have shown that interleukin (IL)-10-producing regulatory B cells (B(regs)) and CD4+CD25+FoxP3+ regulatory T cells (T(regs)) induced by parasite infection play a critical role in allergic or autoimmune diseases because these cells regulate negatively cellular immune responses and inflammation. Currently, the role of IL-10-producing regulatory B cells in host immune response during T. gondii infection is unknown. In this study, we investigate whether T. gondii infection can suppress the development of unrelated atopic dermatitis (AD)-like lesions. AD is a chronically relapsing inflammatory skin disease accompanied by severe itching; for this, we used NC/Nga mice, a well-known experimental model of systemic AD. Repeated exposure to Dermatophagoides farinae crude extract (DfE), known as a major environmental allergen, evokes AD-like skin lesions in NC/Nga mice under specific pathogen-free conditions. NC/Nga mice were intraperitoneally infected with 10 cysts of T. gondii. T. gondii infection significantly ameliorated AD-like skin lesions in NC/Nga mice. The subpopulation of B(regs) and T(regs) in the AD mice was expanded in the course of T. gondii infection. In addition, T. gondii infection inhibited Th2 and enhanced Th1 immune response in the DfE-treated AD mice. We have experimentally demonstrated for the first time that T. gondii infection ameliorated AD-like skin lesions in a mouse model of AD. Our study could in part explain the mechanisms of how parasite infection prevents the development of allergic disorder. Therefore, these immunemechanisms induced by T. gondii infection may be beneficial for the host in terms of reduced risk of allergic immune reactions.

  14. Molecular detection of Toxoplasma gondii DNA in milk and risk factors analysis of seroprevalence in pregnant women at Sharkia, Egypt

    Directory of Open Access Journals (Sweden)

    Heba A. Ahmed

    2014-08-01

    Full Text Available Aim: Toxoplasmosis is one of the most important zoonotic parasitic diseases worldwide. Infection is not only acquired by contact with the definitive host, but also by ingestion of raw milk and milk products. The aim of the study was to detect T. gondii DNA in milk samples, and to estimate anti-T. gondii antibodies in pregnant women for the analysis of the associated risk factors. Materials and Methods: The study involved molecular examination of 150 milk samples collected from rural settings at Sharkia, Egypt. Seroprevalence of anti-T. gondii antibodies was determined in 100 pregnant women by indirect haemagglutination test. The analysis of risk factors associated with seropositive results was assessed by univariate and multivariate logistic regression. Results: T. gondii DNA was detected in 8% and 2% of goat and sheep milk samples, respectively, while none of cow milk samples were positive. Seroprevalence of T. gondii antibodies in pregnant women was 82%, anti-T. gondii-IgG and anti-T. gondii-IgM were detected in 63% and 11% serum samples, respectively. The results showed a significant correlation between the seroprevalence and the contact with cats and consumption of raw milk and homemade cheese. Conclusion: The role of raw milk in transmission of T. gondii cannot be excluded. Contact with cats remains the main risk factor for acquiring T. gondii infection; also consumption of raw milk and milk products is considered an important risk factor. Further large scale studies are recommended to clarify the association of T. gondii seroprevalence with different risk factors.

  15. Genotyping of samples from German patients with ocular, cerebral and systemic toxoplasmosis reveals a predominance of Toxoplasma gondii type II.

    Science.gov (United States)

    Herrmann, Daland C; Maksimov, Pavlo; Hotop, Andrea; Groß, Uwe; Däubener, Walter; Liesenfeld, Oliver; Pleyer, Uwe; Conraths, Franz J; Schares, Gereon

    2014-10-01

    Toxoplasmosis is an important zoonosis transmitted from animals to humans world-wide. In order to determine Toxoplasma gondii genotypes in individuals living in Germany and to compare findings with those in animals, we analysed nine independent and unlinked genetic markers (nSAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1 and Apico) by PCR-RFLP in 83 archived T. gondii-positive DNA samples from patients with ocular toxoplasmosis (n=35), toxoplasmic encephalitis (n=32), systemic toxoplasmosis after bone-marrow transplantation (n=15) and congenital toxoplasmosis (n=1). In 46 of these 83 samples the presence of T. gondii DNA was confirmed by conventional end-point PCR. Among these, 17 T. gondii-positive samples were typed at all nine loci. The majority (15/17, 88.2%) of these samples were of T. gondii type II (i.e., including both, the Apico type II and Apico type I variants). In addition, in one sample a T. gondii type II/type III allele combination and in another sample a T. gondii genotype displaying type III alleles at all markers was observed. In the remaining 11 samples, in which T. gondii could only be partially typed, exclusively type II (n=10) or type III (n=1) alleles were observed. Results of the present study suggest that the majority of patients in Germany are infected with type II T. gondii regardless of the clinical manifestation of toxoplasmosis. This finding is in accord with the predominance of type II T. gondii in oocysts isolated from cats and in tissues of other intermediate hosts in Germany. Copyright © 2014 Elsevier GmbH. All rights reserved.

  16. Seroprevalence and Associated Risk Factors for Toxoplasma gondii Infection in Healthy Blood Donors: A Cross-Sectional Study in Sonora, Mexico

    Science.gov (United States)

    Alvarado-Esquivel, Cosme; Rascón-Careaga, Antonio; Hernández-Tinoco, Jesús; Corella-Madueño, María Alba Guadalupe; Sánchez-Anguiano, Luis Francisco; Aldana-Madrid, María Lourdes; Velasquez-Vega, Edgar; Quizán-Plata, Trinidad; Navarro-Henze, José Luis; Badell-Luzardo, Joel Alberto; Gastélum-Cano, José María; Liesenfeld, Oliver

    2016-01-01

    Toxoplasma gondii (T. gondii) can be transmitted by blood transfusion. We determined the prevalence of T. gondii infection in healthy blood donors in Hermosillo city, Mexico, and the association of infection with T. gondii with the sociodemographic, clinical, and behavioral characteristics of blood donors. Four hundred and eight blood donors who attended two public blood banks in Hermosillo city were examined for anti-T. gondii IgG and IgM antibodies by using enzyme-linked immunoassays. Of the 408 blood donors (mean age 31.77 ± 9.52; range 18–60 years old) studied, 55 (13.5%) were positive for anti-T. gondii IgG antibodies, and 12 (21.8%) of them were also positive for anti-T. gondii IgM antibodies. Multivariate analysis showed that seropositivity to T. gondii was associated with age (OR = 1.74; 95% CI: 1.03–2.94; P = 0.03) and tobacco use (OR = 2.09; 95% CI: 1.02–4.29; P = 0.04). Seropositivity to T. gondii was correlated with the number of pregnancies, deliveries, and cesarean sections. The seroprevalence of T. gondii infection in blood donors in Sonora is the highest reported in blood donors in northern Mexico so far. This is the first report of an association of T. gondii exposure and tobacco use. Further research to confirm this association is needed. PMID:27446960

  17. Seroprevalence and Associated Risk Factors for Toxoplasma gondii Infection in Healthy Blood Donors: A Cross-Sectional Study in Sonora, Mexico

    Directory of Open Access Journals (Sweden)

    Cosme Alvarado-Esquivel

    2016-01-01

    Full Text Available Toxoplasma gondii (T. gondii can be transmitted by blood transfusion. We determined the prevalence of T. gondii infection in healthy blood donors in Hermosillo city, Mexico, and the association of infection with T. gondii with the sociodemographic, clinical, and behavioral characteristics of blood donors. Four hundred and eight blood donors who attended two public blood banks in Hermosillo city were examined for anti-T. gondii IgG and IgM antibodies by using enzyme-linked immunoassays. Of the 408 blood donors (mean age 31.77±9.52; range 18–60 years old studied, 55 (13.5% were positive for anti-T. gondii IgG antibodies, and 12 (21.8% of them were also positive for anti-T. gondii IgM antibodies. Multivariate analysis showed that seropositivity to T. gondii was associated with age (OR = 1.74; 95% CI: 1.03–2.94; P=0.03 and tobacco use (OR = 2.09; 95% CI: 1.02–4.29; P=0.04. Seropositivity to T. gondii was correlated with the number of pregnancies, deliveries, and cesarean sections. The seroprevalence of T. gondii infection in blood donors in Sonora is the highest reported in blood donors in northern Mexico so far. This is the first report of an association of T. gondii exposure and tobacco use. Further research to confirm this association is needed.

  18. rROP2 from Toxoplasma gondii as a potential vaccine against oocyst shedding in domestic cats

    Directory of Open Access Journals (Sweden)

    Dauton Luiz Zulpo

    Full Text Available Abstract The aim of the present study was to evaluate oocyst shedding in cats immunized by nasal route with T. gondii proteins ROP2. Twelve short hair cats (Felis catus were divided in three groups G1, G2 and G3 (n=4. Animals from G1 received 100 μg of rROP2 proteins plus 20 μg of Quil-A, G2 received 100 μg of BSA plus 20 μg of Quil-A, and the G3 only saline solution (control group. All treatments were done by intranasal route at days 0, 21, 42, and 63. The challenge was performed in all groups on day 70 with ≅ 800 tissue cysts of ME-49 strain by oral route. Animals from G1 shed less oocysts (86.7% than control groups. ELISA was used to detect anti-rROP2 IgG and IgA, however, there were no correlation between number of oocyst shedding by either IgG or IgA antibody levels. In the present work, in spite of lesser oocysts production in immunized group than control groups, it was not possible to associate the use of rROP2 via nostrils with protection against oocyst shedding. For the future, the use of either other recombinant proteins or DNA vaccine, in combination with rROP2 could be tested to try improving the efficacy of this kind of vaccine.

  19. Disruption of Toxoplasma gondii Parasitophorous Vacuoles by the Mouse p47-Resistance GTPases.

    Directory of Open Access Journals (Sweden)

    2005-11-01

    Full Text Available The p47 GTPases are essential for interferon-gamma-induced cell-autonomous immunity against the protozoan parasite, Toxoplasma gondii, in mice, but the mechanism of resistance is poorly understood. We show that the p47 GTPases, including IIGP1, accumulate at vacuoles containing T. gondii. The accumulation is GTP-dependent and requires live parasites. Vacuolar IIGP1 accumulations undergo a maturation-like process accompanied by vesiculation of the parasitophorous vacuole membrane. This culminates in disruption of the parasitophorous vacuole and finally of the parasite itself. Over-expression of IIGP1 leads to accelerated vacuolar disruption whereas a dominant negative form of IIGP1 interferes with interferon-gamma-mediated killing of intracellular parasites. Targeted deletion of the IIGP1 gene results in partial loss of the IFN-gamma-mediated T. gondii growth restriction in mouse astrocytes.

  20. Seroprevalence of Toxoplasma gondii infection in zoo and domestic animals in Jiangxi Province, China

    Directory of Open Access Journals (Sweden)

    Luo Houqiang

    2017-01-01

    Full Text Available Toxoplasma gondii is a zoonotic protozoan parasite that infects a wide range of warm-blooded animals throughout the world. In the present study, antibodies to T. gondii were determined using a commercial indirect hemagglutination (IHA test in wild animals in a zoo. Three of 11 giraffes (Giraffa camelopardalis (27%, 1 of 5 wolves (Canis lupus laniger (20%, 1 of 6 hippopotamuses (Hippopotamus amphibious (17%, and 2 of 9 tundra swans (Cygnus columbianus (22% were found to be positive. No antibodies were detected in leopards (Panthera pardus, wild geese (Anser cygnoides, and Eastern grey kangaroos (Macropus giganteus. Domestic species from 13 counties of Jiangxi Province, China were also investigated by an indirect hemagglutination (IHA test. Thirty-five of 340 goats (10%, 94 of 560 water buffaloes (17%, and 4 of 35 cattle (11% were found to be seropositive. This is the first report of T. gondii infection in animals kept in zoos and domestic animals in this province.

  1. Toxoplasma gondii peptide ligands open the gate of the HLA class I binding groove

    DEFF Research Database (Denmark)

    McMurtrey, Curtis; Trolle, Thomas; Sansom, Tiffany

    2016-01-01

    N-terminal binding core yet exhibit a C-terminal extension of 1-30 amino acids. Structural analysis demonstrates that binding of extended peptides opens the HLA class I F' pocket, allowing the C-terminal extension to protrude through one end of the binding groove. In summary, we demonstrate...... that unrealized structural flexibility makes MHC class I receptive to parasite-derived ligands that exhibit unique C-terminal peptide extensions.......HLA class I presentation of pathogen-derived peptide ligands is essential for CD8+ T cell recognition of Toxoplasma gondii infected cells. Currently, little data exist pertaining to peptides that are presented after T. gondii infection. Herein we purify HLA-A*02:01 complexes from T. gondii infected...

  2. Seroprevalence of Toxoplasma gondii infection in domestic cats in central China.

    Science.gov (United States)

    Wang, Shuai; Zhou, Yonghua; Niu, Jingyuan; Xie, Qing; Xiao, Tingwei; Chen, Yunchao; Li, Han; Ma, Chenchen; Zhang, Haizhu; Liu, Shiguo; Zhang, Zhenchao

    2017-01-01

    To investigate the seroprevalence of Toxoplasma gondii infection in domestic cats in central China, 843 serum samples were collected in Henan province between March 2015 and May 2016 and tested for IgG antibodies against T. gondii using the enzyme-linked immunosorbent assay (ELISA). The overall seroprevalence of T. gondii was 21% (178/843). No significant difference was observed based on the sex of cats (p > 0.05). Significantly higher seroprevalence (p cats (24%) compared to purebred cats (17%). Seroprevalence in rural cats (29%) was significantly higher (p cats (16%), and increased significantly (p domestic cats in Henan province, central China, which might have important implications for public health. © S. Wang et al., published by EDP Sciences, 2017.

  3. Seroprevalence of Toxoplasma gondii infection in Liaoning cashmere goat from northeastern China.

    Science.gov (United States)

    Xu, Peng; Li, Xia; Guo, Ling; Li, Bing; Wang, Jun; Yu, Di; Zhao, Quan; Liu, Xiao-Gang

    2014-01-01

    In the present study, serum samples from 650 goats were collected from five counties between May and June 2012 and antibodies to Toxoplasma gondii were detected by indirect haemagglutination assay; 58 (9%) had antibodies to T. gondii with antibody titres of 1:64 to 1:1024. Seropositive samples were distributed in all five counties: seroprevalences in Kuandian county (15%, 21/139, 95% confidence interval [CI] 9-21%) were statistically different from the four other counties (Gaizhou, Huanren, Xiuyan and Liaoyang), and the seroprevalence difference between Xiuyan county (12%, 15/127, 95% CI 6-17%) and two other counties (Huanren, Liaoyang) was significantly different (P cashmere goat in China. Our results indicated that Liaoning cashmere goat could be a potential reservoir for the transmission of T. gondii in Liaoning Province. © P. Xu et al., published by EDP Sciences, 2014.

  4. Sieroepidemiologia delle infezioni da Toxoplasma gondii, virus della Rosolia e Citomegalovirus in una coorte di gravide

    Directory of Open Access Journals (Sweden)

    Marco Moretti

    2006-06-01

    Full Text Available Toxoplasma gondii, Rubella virus and Citomegalovirus are responsible for maternal-fetal infections that can cause severe consequences in fetus. The surveillance of these infections in pregnancy is made by specific antibodies detection and when necessary by demostrating the presence of the infectious agent in body fluids. We have evaluated the seroprevalence of antibodies in a cohort of 1100 pregnant women against Toxoplasma gondii, Rubella virus and Citomegalovirus. Our data show a low seroprevalence against Toxoplasma gondii, a suboptimal immunitary coverage against Rubella virus and a significative increase of incidence in Citomegalovirus infection. The study suggests the need of a multiprofessional and multidisciplinary approach for the right management of these maternal-fetal infections and underlines the pivot role played by Clinical Pathologists.

  5. Contamination of poultry meat with Toxoplasma gondii: Risk factor in occurrence of toxoplasmatic reaction in humans

    Directory of Open Access Journals (Sweden)

    Pavlović Ivan

    2002-01-01

    Full Text Available Toxoplasmosis is a parasitic anthropozoonosis caused by the protozoa Toxoplasma gondii whose real host is the cat and the transitory hosts are mammals, birds and reptiles. Human infections occur most often through meat of infected animals which is insufficiently processed thermally, so that the World Health Organization (WHO, on these grounds, adopted a Book of Regulations on meat control for the presence of T. gondii. During the period from 2000-2001, using digestive and modified digestive method (according to Pavlovic and Ivanovic, 235 broiler samples were examined, and T. gondii was established in 32.34 % samples (75/256. The results were confirmed with a biological examination. These data indicate the importance of poultry meat control in preventing toxoplasmatic infection in humans.

  6. Comparison of detection methods for Toxoplasma gondii in naturally and experimentally infected swine.

    Science.gov (United States)

    Hill, Dolores E; Chirukandoth, Sreekumar; Dubey, J P; Lunney, Joan K; Gamble, H Ray

    2006-10-10

    Results from recent serological surveys and epidemiological studies show that pigs raised in a variety of management systems can be carriers of the tissue cyst stage of Toxoplasma gondi. This parasite can be transmitted to humans through the consumption of improperly prepared pork, making detection and removal of infected swine carcasses from the food chain an important food safety issue. Several methods are available for detection of T. gondii infected swine, including serological assays, polymerase chain reaction, and animal bioassays. The aim of the present study was to compare the detection sensitivities of six of these commonly used methods for detection of T. gondii infection in tissues from naturally and experimentally infected pigs. The results indicate that a serum-based ELISA is the most sensitive method, of those tested, for detection of T. gondii infected swine.

  7. Changing climate-changing pathogens: Toxoplasma gondii in North-Western Europe.

    Science.gov (United States)

    Meerburg, Bastiaan G; Kijlstra, Aize

    2009-07-01

    In this review, we describe the effects of global climate change for one specific pathogen: the parasite Toxoplasma gondii. It is postulated that an increase of T. gondii prevalence in humans can occur in some regions of North-Western Europe as a result of changing environmental conditions. Such a change can be predicted by using Global Climate Change models. We have elaborated such a prediction for one scenario (SRES A1) by using one specific model (CCSR/NRIES) as an example. Next to environmental factors, also anthropogenic factors may contribute to increased prevalence of T. gondii in this region. In order to counter the potential severe consequences of a potential increase resulting from the combination of climatic and anthropogenic factors, there is an urgent need for the development of a human vaccine. Until a vaccine that offers complete protection is developed, the emphasis should be on treatment optimization and prevention.

  8. Toxoplasma gondii infection reduces predator aversion in rats through epigenetic modulation in the host medial amygdala.

    Science.gov (United States)

    Hari Dass, Shantala Arundhati; Vyas, Ajai

    2014-12-01

    Male rats (Rattus novergicus) infected with protozoan Toxoplasma gondii relinquish their innate aversion to the cat odours. This behavioural change is postulated to increase transmission of the parasite to its definitive felid hosts. Here, we show that the Toxoplasma gondii infection institutes an epigenetic change in the DNA methylation of the arginine vasopressin promoter in the medial amygdala of male rats. Infected animals exhibit hypomethylation of arginine vasopressin promoter, leading to greater expression of this nonapeptide. The infection also results in the greater activation of the vasopressinergic neurons after exposure to the cat odour. Furthermore, we show that loss of fear in the infected animals can be rescued by the systemic hypermethylation and recapitulated by directed hypomethylation in the medial amygdala. These results demonstrate an epigenetic proximate mechanism underlying the extended phenotype in the Rattus novergicus-Toxoplasma gondii association. © 2014 John Wiley & Sons Ltd.

  9. A novel polymer of tubulin forms the conoid of Toxoplasma gondii

    Science.gov (United States)

    Hu, Ke; Roos, David S.; Murray, John M.

    2002-01-01

    Toxoplasma gondii is an obligatory intracellular parasite, an important human pathogen, and a convenient laboratory model for many other human and veterinary pathogens in the phylum Apicomplexa, such as Plasmodium, Eimeria, and Cryptosporidia. 22 subpellicular microtubules form a scaffold that defines the cell shape of T. gondii. Its cytoskeleton also includes an intricate apical structure consisting of the conoid, two intraconoid microtubules, and two polar rings. The conoid is a 380-nm diameter motile organelle, consisting of fibers wound into a spiral like a compressed spring. FRAP analysis of transgenic T. gondii expressing YFP-α-tubulin reveals that the conoid fibers are assembled by rapid incorporation of tubulin subunits during early, but not late, stages of cell division. Electron microscopic analysis shows that in the mature conoid, tubulin is arranged into a novel polymer form that is quite different from typical microtubules. PMID:11901169

  10. Anti-gluten immune response following Toxoplasma gondii infection in mice.

    Directory of Open Access Journals (Sweden)

    Emily G Severance

    Full Text Available Gluten sensitivity may affect disease pathogenesis in a subset of individuals who have schizophrenia, bipolar disorder or autism. Exposure to Toxoplasma gondii is a known risk factor for the development of schizophrenia, presumably through a direct pathological effect of the parasite on brain and behavior. A co-association of antibodies to wheat gluten and to T. gondii in individuals with schizophrenia was recently uncovered, suggesting a coordinated gastrointestinal means by which T. gondii and dietary gluten might generate an immune response. Here, we evaluated the connection between these infectious- and food-based antigens in mouse models. BALB/c mice receiving a standard wheat-based rodent chow were infected with T. gondii via intraperitoneal, peroral and prenatal exposure methods. Significant increases in the levels of anti-gluten IgG were documented in all infected mice and in offspring from chronically infected dams compared to uninfected controls (repetitive measures ANOVAs, two-tailed t-tests, all p≤0.00001. Activation of the complement system accompanied this immune response (p≤0.002-0.00001. Perorally-infected females showed higher levels of anti-gluten IgG than males (p≤0.009 indicating that T. gondii-generated gastrointestinal infection led to a significant anti-gluten immune response in a sex-dependent manner. These findings support a gastrointestinal basis by which two risk factors for schizophrenia, T. gondii infection and sensitivity to dietary gluten, might be connected to produce the immune activation that is becoming an increasingly recognized pathology of psychiatric disorders.

  11. toxoMine: an integrated omics data warehouse for Toxoplasma gondii systems biology research.

    Science.gov (United States)

    Rhee, David B; Croken, Matthew McKnight; Shieh, Kevin R; Sullivan, Julie; Micklem, Gos; Kim, Kami; Golden, Aaron

    2015-01-01

    Toxoplasma gondii (T. gondii) is an obligate intracellular parasite that must monitor for changes in the host environment and respond accordingly; however, it is still not fully known which genetic or epigenetic factors are involved in regulating virulence traits of T. gondii. There are on-going efforts to elucidate the mechanisms regulating the stage transition process via the application of high-throughput epigenomics, genomics and proteomics techniques. Given the range of experimental conditions and the typical yield from such high-throughput techniques, a new challenge arises: how to effectively collect, organize and disseminate the generated data for subsequent data analysis. Here, we describe toxoMine, which provides a powerful interface to support sophisticated integrative exploration of high-throughput experimental data and metadata, providing researchers with a more tractable means toward understanding how genetic and/or epigenetic factors play a coordinated role in determining pathogenicity of T. gondii. As a data warehouse, toxoMine allows integration of high-throughput data sets with public T. gondii data. toxoMine is also able to execute complex queries involving multiple data sets with straightforward user interaction. Furthermore, toxoMine allows users to define their own parameters during the search process that gives users near-limitless search and query capabilities. The interoperability feature also allows users to query and examine data available in other InterMine systems, which would effectively augment the search scope beyond what is available to toxoMine. toxoMine complements the major community database ToxoDB by providing a data warehouse that enables more extensive integrative studies for T. gondii. Given all these factors, we believe it will become an indispensable resource to the greater infectious disease research community. © The Author(s) 2015. Published by Oxford University Press.

  12. Toxoplasma gondii in raw and dry-cured ham: The influence of the curing process.

    Science.gov (United States)

    Herrero, Laura; Gracia, María Jesús; Pérez-Arquillué, Consuelo; Lázaro, Regina; Herrera, Antonio; Bayarri, Susana

    2017-08-01

    The aim of this work was to analyze Toxoplasma gondii in raw hams by mouse bioassay and to evaluate the effect of curing on the viability of the parasite to assess the risk of infection from eating dry-cured ham. After a serology study of 1200 pigs in Aragón (Spain), forty-one naturally infected pigs with different serological titers against T. gondii were selected. Two cured periods (9 and 12 months) were evaluated as well as the influence of the physicochemical composition of hams on T. gondii survival. Although the parasite burden was low, a high number of seropositive pigs with Toxoplasma tissues cysts in raw hams were found (31.6%). Viability of T. gondii was influenced by the curing, with statistically significant differences between fresh and cured hams (p hams cured for 9 months compared to those cured for 12 months. However, this period of curing resulted in the reduction but not in a complete elimination of the risk. Thus, from a public health point of view, under the conditions of this study it is safer to consume dry-cured ham with periods of curing higher than 12 months. Analysis of physicochemical results did not identify any variable with significant influence on the presence and viability of T. gondii in cured ham, but loss of viability of T. gondii was observed in hams with a lower fat content. Further research is required to validate combinations of salts concentration and time of curing that can be used as preventive measures in the HACCP system of dry-cured ham industry. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Human impact on genetic diversity of Toxoplasma gondii: example of the anthropized environment from French Guiana.

    Science.gov (United States)

    Mercier, A; Ajzenberg, D; Devillard, S; Demar, M P; de Thoisy, B; Bonnabau, H; Collinet, F; Boukhari, R; Blanchet, D; Simon, S; Carme, B; Dardé, M-L

    2011-08-01

    In French Guiana, severe cases of toxoplasmosis in immunocompetent patients are associated with atypical strains of Toxoplasma gondii linked to a wild neotropical rainforest cycle and a higher genetic diversity than usually observed for T. gondii isolates from anthropized environment. This raises the question of the impact of anthropization of the natural environment, on genetic diversity and on the population structure of T. gondii. However, few data are available on strains circulating in the anthropized areas from French Guiana. Seropositive animals originating mainly from anthropized sub-urban areas and punctually from wild environment in French Guiana were analyzed for T. gondii isolation and genotyping. Thirty-three strains were obtained by bioassay in mice and compared with 18 previously reported isolates chiefly originating from the Amazon rainforest. The genotyping analysis performed with 15 microsatellite markers located on 12 different chromosomes revealed a lower genetic diversity in the anthropized environment. Results were analyzed in terms of population structure by clustering methods, Neighbor-joining trees reconstruction based on genetic distances, F(ST,) Mantel's tests and linkage disequilibrium. They clearly showed a genetic differentiation between strains associated to the anthropized environment and those associated to the wild, but with some inbreeding between them. The majority of strains from the anthropized environment were clustered into additional lineages of T. gondii that are common in the Caribbean. In conclusion the two environmental populations "wild" and "anthropized" were genetically well differentiated. The anthropization of the environment seems to be accompanied with a decreased diversity of T. gondii associated with a greater structure of the populations. We detected potential interpenetration and genetic exchanges between these two environmental populations. As a higher pathogenicity in human of "wild" genotypes has been

  14. Age-related Toxoplasma gondii seroprevalence in Dutch wild boar inconsistent with lifelong persistence of antibodies.

    Directory of Open Access Journals (Sweden)

    Marieke Opsteegh

    Full Text Available Toxoplasma gondii is an important zoonotic pathogen that is best known as a cause of abortion or abnormalities in the newborn after primary infection during pregnancy. Our aim was to determine the prevalence of T. gondii in wild boar to investigate the possible role of their meat in human infection and to get an indication of the environmental contamination with T. gondii. The presence of anti-T. gondii antibodies was determined by in-house ELISA in 509 wild boar shot in 2002/2003 and 464 wild boar shot in 2007. Most of the boar originated from the "Roerstreek" (n = 673 or the "Veluwe" (n = 241. A binormal mixture model was fitted to the log-transformed optical density values for wild boar up to 20 months old to estimate the optimal cut-off value (-0.685 and accompanying sensitivity (90.6% and specificity (93.6%. The overall seroprevalence was estimated at 24.4% (95% CI: 21.1-27.7%. The prevalence did not show variation between sampling years or regions, indicating a stable and homogeneous infection pressure from the environment. The relation between age and seroprevalence was studied in two stages. Firstly, seroprevalence by age group was determined by fitting the binary mixture model to 200 animals per age category. The prevalence showed a steep increase until approximately 10 months of age but stabilized at approximately 35% thereafter. Secondly, we fitted the age-dependent seroprevalence data to several SIR-type models, with seropositives as infected (I and seronegatives as either susceptible (S or resistant (R. A model with a recovery rate (SIS was superior to a model without a recovery rate (SI. This finding is not consistent with the traditional view of lifelong persistence of T. gondii infections. The high seroprevalence suggests that eating undercooked wild boar meat may pose a risk of infection with T. gondii.

  15. Anti-Gluten Immune Response following Toxoplasma gondii Infection in Mice

    Science.gov (United States)

    Severance, Emily G.; Kannan, Geetha; Gressitt, Kristin L.; Xiao, Jianchun; Alaedini, Armin; Pletnikov, Mikhail V.; Yolken, Robert H.

    2012-01-01

    Gluten sensitivity may affect disease pathogenesis in a subset of individuals who have schizophrenia, bipolar disorder or autism. Exposure to Toxoplasma gondii is a known risk factor for the development of schizophrenia, presumably through a direct pathological effect of the parasite on brain and behavior. A co-association of antibodies to wheat gluten and to T. gondii in individuals with schizophrenia was recently uncovered, suggesting a coordinated gastrointestinal means by which T. gondii and dietary gluten might generate an immune response. Here, we evaluated the connection between these infectious- and food-based antigens in mouse models. BALB/c mice receiving a standard wheat-based rodent chow were infected with T. gondii via intraperitoneal, peroral and prenatal exposure methods. Significant increases in the levels of anti-gluten IgG were documented in all infected mice and in offspring from chronically infected dams compared to uninfected controls (repetitive measures ANOVAs, two-tailed t-tests, all p≤0.00001). Activation of the complement system accompanied this immune response (p≤0.002–0.00001). Perorally-infected females showed higher levels of anti-gluten IgG than males (p≤0.009) indicating that T. gondii-generated gastrointestinal infection led to a significant anti-gluten immune response in a sex-dependent manner. These findings support a gastrointestinal basis by which two risk factors for schizophrenia, T. gondii infection and sensitivity to dietary gluten, might be connected to produce the immune activation that is becoming an increasingly recognized pathology of psychiatric disorders. PMID:23209841

  16. Seroepidemiology of Toxoplasma gondii Infection among healthy blood donors in Taiwan.

    Directory of Open Access Journals (Sweden)

    Ting-Yi Chiang

    Full Text Available Toxoplasma gondii is an opportunistic, zoonotic pathogen with a worldwide distribution. There are large variations in the seroprevalence of T. gondii infection in different regions of the world. Although toxoplasmosis became a notifiable communicable disease in Taiwan in 2007, little is known about its epidemiology among the general population. This cross-sectional study aimed to survey the seroprevalence of T. gondii infection and its risk factors among healthy blood donors in Taiwan. Through collaborating with the Taiwan Blood Services Foundation, a total of 1,783 healthy blood donors from all six-branch blood service centers participated in this study. The blood samples were tested for the presence of T. gondii antibodies and DNA using enzyme immunoassays and real-time PCR, respectively. Structured questionnaires were used to gather information on risk factors for T. gondii infection. Of the 1,783 participants, 166 (9.3% tested positive for anti-Toxoplasma IgG, while 5 (0.28% tested positive for anti-Toxoplasma IgM. The five IgM positive donors had high avidity antibodies suggestive of past infection. No active parasitemia was detected by real-time PCR assays. Multivariate logistic regression showed that undercooked pork meat consumption (adjusted odds ratio [OR] = 2.9; 95% confidence interval [CI]: 1.3-6.5, raw mussels consumption (adjusted OR = 5.3; 95% CI: 1.5-19.1, having a cat in the household (adjusted OR = 2.0; 95% CI: 1.2-3.2, a lower education level (adjusted OR = 1.6; 95% CI: 1.1-2.3, and donation place in eastern Taiwan (adjusted OR = 2.5; 95% CI: 1.6-3.9 were independent risk factors for Toxoplasma seropositivity. These findings provide information on the seroprevalence and epidemiology of T. gondii infection among healthy blood donors in Taiwan.

  17. A seroepidemiological survey of Toxoplasma gondii infection in referred dogs to Veterinary Hospital of Ahvaz, Iran

    Directory of Open Access Journals (Sweden)

    Fatemeh Zarra-Nezhad

    2017-12-01

    Full Text Available Toxoplasma gondii is an intracellular protozoan parasite, which is the cause of toxoplasmosis and can infect a wide variety of warm-blooded animals, including dogs and humans. The present study evaluated the seroprevalence of T. gondii infection in pet dogs in Ahvaz, southwest city of Iran, and investigated the related possible risk factors. A total of 180 serum samples were collected from dogs referred to Veterinary Hospital of Ahvaz. The samples were then tested by indirect enzyme-linked immunosorbent assay. The prevalence of T. gondii antibodies were 46.67%. Logistic regression and chi square tests were used for evaluating of risk factors. The positivity increased statistically significantly with dog’s gender (56% females and 39% males, P = 0.001, age (18% in <2 years old, 96% in ≥4 years old, P = 0.001 and place of living (47% outdoor dogs 38% house hold dogs, P = 0.025. However, no statistically significant association was found with dogs’ breed, deworming, food ingestion or contact with cats. Overall, the results showed a relatively high seroprevalence of T. gondii infection in dogs in southwest Iran (Ahvaz and proved association of T. gondii prevalence rates with the dog’s age, gender and place of living. Keywords: Toxoplasma gondii, Toxoplasmosis, Indirect enzyme-linked immunosorbent assay, Outdoor dogs, House hold dogs, Deworming

  18. Toxoplasma gondii Serology and Outcomes After Heart Transplantation: Contention in the Literature.

    Science.gov (United States)

    Chehrazi-Raffle, A; Luu, M; Yu, Z; Liou, F; Kittleson, M; Hamilton, M; Kobashigawa, J

    2015-01-01

    Toxoplasma gondii is an endemic pathogen to which approximately half of healthy patients develop antibodies. Toxoplasma serology is routinely assessed prior to heart transplantation. It has been suggested that donor or recipient toxoplasma serologic status may be associated with poor long-term outcomes post-transplantation, but current literature reveals conflicting results. From 1995 to 2012 at our single center, we retrospectively reviewed 785 heart transplant patients for pre-transplantation T. gondii serology. Patients were divided into T. gondii seronegative and seropositive groups. Subgroups in each group were created based on whether the donor was seropositive or seronegative. We assessed survival, freedom from nonfatal major adverse cardiac events, and freedom from cardiac allograft vasculopathy at 5 years post-transplantation. No significant difference was found between 5-year outcomes of pre-transplant T. gondii seronegative and T. gondii seropositive recipients post-heart transplantation. However, in the donor-seropositive/recipient-seronegative subgroup (D+/R-), there was a significantly lower 5-year survival rate compared to the cohort of donor-seronegative/recipient-seronegative (D-/R-) patients (60% vs 87%, P = .04). After adjustment by multivariate analysis, D+/R- status conferred a trend towards increased mortality (HR 3.0, P = .06). Toxoplasma serology prior to heart transplantation does not appear to impact post-transplantation outcome. However, toxoplasma seronegative patients who receive toxoplasma seropositive hearts appear to have poorer 5-year survival compared to toxoplasma seronegative patients who received toxoplasma seronegative hearts. Due to the small sample size, the association between T. gondii serology mismatch and long-term survival warrants further study. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. Recombinant Toxoplasma gondii phosphoglycerate mutase 2 confers protective immunity against toxoplasmosis in BALB/c mice.

    Science.gov (United States)

    Wang, Hai-Long; Wen, Li-Min; Pei, Yan-Jiang; Wang, Fen; Yin, Li-Tian; Bai, Ji-Zhong; Guo, Rui; Wang, Chun-Fang; Yin, Guo-Rong

    2016-01-01

    Toxoplasmosis is one of the most widespread zoonoses worldwide. It has a high incidence and can result in severe disease in humans and livestock. Effective vaccines are needed to limit and prevent infection with Toxoplasma gondii. In this study, we evaluated the immuno-protective efficacy of a recombinant Toxoplasma gondii phosphoglycerate mutase 2 (rTgPGAM 2) against T. gondii infection in BALB/c mice. We report that the mice nasally immunised with rTgPGAM 2 displayed significantly higher levels of special IgG antibodies against rTgPGAM 2 (including IgG1, IgG2a and IgAs) and cytokines (including IFN-γ, IL-2 and IL-4) in their blood sera and supernatant of cultured spleen cells compared to those of control animals. In addition, an increased number of spleen lymphocytes and enhanced lymphocyte proliferative responses were observed in the rTgPGAM 2-immunised mice. After chronic infection and lethal challenge with the highly virulent T. gondii RH strain by oral gavage, the survival time of the rTgPGAM 2-immunised mice was longer (P < 0.01) and the survival rate (70%) was higher compared with the control mice (P < 0.01). The reduction rate of brain and liver tachyzoites in rTgPGAM 2-vaccinated mice reached approximately 57% and 69% compared with those of the control mice (P < 0.01). These results suggest that rTgPGAM 2 can generate protective immunity against T. gondii infection in BALB/c mice and may be a promising antigen in the further development of an effective vaccine against T. gondii infection. © H.-L. Wang et al., published by EDP Sciences, 2016.

  20. An inside job: hacking into Janus kinase/signal transducer and activator of transcription signaling cascades by the intracellular protozoan Toxoplasma gondii.

    Science.gov (United States)

    Denkers, Eric Y; Bzik, David J; Fox, Barbara A; Butcher, Barbara A

    2012-02-01

    The intracellular protozoan Toxoplasma gondii is well known for its skill at invading and living within host cells. New discoveries are now also revealing the astounding ability of the parasite to inject effector proteins into the cytoplasm to seize control of the host cell. This review summarizes recent advances in our understanding of one such secretory protein called ROP16. This molecule is released from rhoptries into the host cell during invasion. The ROP16 molecule acts as a kinase, directly activating both signal transducer and activator of transcription 3 (STAT3) and STAT6 signaling pathways. In macrophages, an important and preferential target cell of parasite infection, the injection of ROP16 has multiple consequences, including downregulation of proinflammatory cytokine signaling and macrophage deviation to an alternatively activated phenotype.

  1. Prevalence of Toxoplasma gondii infections in Pennsylvania black bears, Ursus americanus.

    Science.gov (United States)

    Briscoe, N; Humphreys, J G; Dubey, J P

    1993-10-01

    Serum samples from 665 hunter-killed black bears killed in 1989 to 1992 throughout Pennsylvania (USA) were tested for Toxoplasma gondii antibodies by the agglutination test in dilutions of 1:25, 1:50, and 1:500. Toxoplasma gondii antibodies were found in 535 of 665 (80%) bears. Considering the highest dilutions at which antibodies were detected, prevalences were 10% at 1:25, 37% at 1:50 and 33% at 1:500. No significant difference in antibody prevalence was found between males (79%) and females (80%), but a significant difference was found between juvenile (65%) and adult (83%) bears.

  2. Seroprevalence of Toxoplasma gondii and Trichinella spiralis in North Carolina black bears (Ursus americanus).

    Science.gov (United States)

    Nutter, F B; Levine, J F; Stoskopf, M K; Gamble, H R; Dubey, J P

    1998-10-01

    Serum samples from 143 hunter-killed black bears were collected during the 1996 and 1997 black bear hunting seasons in eastern North Carolina. All samples were tested for antibodies to Toxoplasma gondii by the modified agglutination test. Antibodies to T. gondii were present in 120 of 143 (84%) bears. Females had significantly higher titers than males (Wilcoxon rank sums test, P = 0.045), and titers increased with age (Jonckheere test, P = 0.01). Samples collected during 1996 (n = 79) were tested for antibodies to Trichinella spiralis by enzyme-linked immunosorbent assay. No samples were positive for antibodies to T. spiralis.

  3. Pathology, clinical signs, and tissue distribution of Toxoplasma gondii in experimentally infected reindeer (Rangifer tarandus

    Directory of Open Access Journals (Sweden)

    Émilie Bouchard

    2017-12-01

    Full Text Available Toxoplasma gondii is a zoonotic parasite found in vertebrates worldwide for which felids serve as definitive hosts. Despite low densities of felids in northern Canada, Inuit people in some regions show unexpectedly high levels of exposure, possibly through handling and consumption of Arctic wildlife. Free-ranging caribou (Rangifer tarandus are widely harvested for food across the Canadian North, show evidence of seroexposure to T. gondii, and are currently declining in numbers throughout the Arctic. We experimentally infected three captive reindeer (conspecific with caribou with 1000, 5000 or 10,000 oocysts of T. gondii via stomach intubation to assess clinical signs of infection, pathology, and tissue distribution. An unexposed reindeer served as a negative control. Signs of stress, aggression, and depression were noted for the first two weeks following infection. By 4 weeks post infection, all infected reindeer were positive on a modified agglutination test at the highest titer tested (1:200 for antibodies to T. gondii. At 20 weeks post infection, no gross abnormalities were observed on necropsy. Following histopathology and immunohistochemistry, tissue cysts were visualized in the reindeer given the highest and lowest dose of oocysts. Focal pleuritis and alveolitis were associated with respiratory problems in reindeer given the middle dose. DNA of T. gondii was detected following traditional DNA extraction and conventional PCR on 25 mg samples from 17/33 muscles and organs, and by magnetic capture DNA extraction from 100 g samples from all 26 tissues examined. This research demonstrated that reindeer/caribou can serve as intermediate hosts for T. gondii, and that the parasite may be associated with health effects in wildlife. The presence of T. gondii in all tissues tested, many of which are commonly consumed raw, smoked, or dried in northern communities, suggests that caribou may serve as a source of human exposure to T. gondii

  4. Toxoplasma gondii seroprevalence and genotype diversity in select wildlife species from the southeastern United States

    Directory of Open Access Journals (Sweden)

    Richard W. Gerhold

    2017-10-01

    Full Text Available Abstract Background Toxoplasma gondii is a widespread protozoan parasite that infects humans and other animals. Previous studies indicate some genotypes of T. gondii are more frequently isolated in wildlife than agricultural animals, suggesting a wild/feral animal diversity model. To determine seroprevalence and genetic diversity of T. gondii in southeastern US wildlife, we collected sera from 471 wild animals, including 453 mammals and 18 birds, between 2011 and 2014. These serum samples were assayed for T. gondii infection using the modified agglutination test (MAT. Heart or tongue tissues from 66 seropositive animals were bioassayed in mice and 19 isolates were obtained. The isolated parasites were genotyped by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP method employing 10 genetic markers. Results One hundred and ninety-six of 471 samples (41.6% had a titer ≥1:32 and were considered positive for T. gondii infection. Of 453 mammals, 195 (43% were seropositive, whereas only one (5.6% of 18 birds was seropositive. The seroprevalence in mammals was significantly higher than in the birds. Mammalian hosts with adequate samples size (≥ 20 comprised white-tailed deer (n = 241, feral hogs (n = 100, raccoons (n = 34 and coyotes (n = 22, with seroprevalences of 41.0%, 51.0%, 50.0% and 72.7%, respectively. Coyotes had significantly higher seroprevalence than the white-tailed deer. Genotyping revealed five distinct genotypes, including the ToxoDB PCR-RFLP genotype #5 (a.k.a type 12 for 15 isolates, genotype #3 (a.k.a. type II for 1 isolate, and genotypes #154, #167 and #216, each for 1 isolate. The results showed moderate to high infection rates of T. gondii in white-tailed deer, feral hogs, raccoons and coyotes. Genotyping results indicated limited genetic diversity and a dominance of genotype #5, which has been reported as a major type in wildlife in North America. Conclusions We conclude that T. gondii

  5. Seroepidemiology of Toxoplasma gondii in dogs in the State of Rio de Janeiro

    Directory of Open Access Journals (Sweden)

    Nathalie Costa da Cunha

    2016-11-01

    Full Text Available ABSTRACT. Cunha N.C., Cordeiro M.D., Bravo S.A.C., Matos P.C.M., Almosny N.R.P. & da Fonseca A.H. [Seroepidemiology of Toxoplasma gondii in dogs in the State of Rio de Janeiro.] Soroepidemiologia de Toxoplasma gondii em cães no estado do Rio de Janeiro. Revista Brasileira de Medicina Veterinária 38(supl. 3: 114-121, 2016. Departamento de Saúde Coletiva Veterinária e Saúde Pública, Faculdade de Veterinária. Universidade Federal Fluminense, Vital Brazil, Niterói, RJ, Brazil. E-mail: nathaliecunha@id.uff.br Toxoplasmosis is a serious public health problem worldwide as it can cause prenatal and neonatal morbidity and mortality in humans. Although dogs are not definitive hosts of T. gondii, they play an important role in the mechanical dissemination of oocysts. This study aimed to carry out a seroepidemiological investigation of anti-Toxoplasma gondii antibodies in domestic dogs from seven municipalities in the state of Rio de Janeiro, Brazil. A crosssectional epidemiological study was carried out to evaluate the profile of anti-Toxoplasma gondii IgG antibodies in dogs from canine sera from different municipalities in the state of Rio de Janeiro. The municipalities studied were Cachoeiras de Macacu, Guapimirim, Itaboraí, Magé, Resende, Seropédica and Silva Jardim. The detection of antibodies of the IgG class anti-Toxoplasma gondii was performed using the indirect enzyme immunoadsorption (ELISA assay and the statistical analyzes used were the chi-square test and the prevalence ratio. Of the 651 samples tested, 300 were reactive for T. gondii, representing a relative frequency of 46.08% of seroreactive dogs. It was concluded that dogs are good sentinels for evaluations of risk for occurrence of T. gondii, emphasizing those coming from rural areas and that there was no difference in the occurrence of serorreative dogs in front of different municipalities studies of the state of Rio de Janeiro.

  6. Prevalence of Toxoplasma gondii in small mammals from the Ardennes region, France.

    Science.gov (United States)

    Afonso, Eve; Poulle, Marie-Lazarine; Lemoine, Mélissa; Villena, Isabelle; Aubert, Dominique; Gilot-Fromont, Emmanuelle

    2007-11-01

    Serum samples from 218 small mammals trapped in forest and grassland in the Ardennes region (North-eastern France) were tested for antibodies to Toxoplasma gondii. Using the modified agglutination test, positive results were found in 4/92 Apodemus sp., 3/64 Clethrionomys glareolus, 0/26 Microtus agrestis, 0/4 Micromys minutus, 3/5 Sorex sp., 2/9 Arvicola terrestris, and 7/18 Talpa europaea. Toxoplasma gondii was not isolated from the heart of seropositive individuals after bioassay in mice. Seroprevalence was significantly higher in large fossorial mammals living in grassland than in small forest mammals, probably related to ecological factors.

  7. Dissecting the molecular assembly of theToxoplasma gondiiMyoA motility complex.

    Science.gov (United States)

    Powell, Cameron J; Jenkins, Meredith L; Parker, Michelle L; Ramaswamy, Raghavendran; Kelsen, Anne; Warshaw, David M; Ward, Gary E; Burke, John E; Boulanger, Martin J

    2017-11-24

    Apicomplexan parasites such as Toxoplasma gondii rely on a unique form of locomotion known as gliding motility. Generating the mechanical forces to support motility are divergent class XIV myosins (MyoA) coordinated by accessory proteins known as light chains. Although the importance of the MyoA-light chain complex is well-established, the detailed mechanisms governing its assembly and regulation are relatively unknown. To establish a molecular blueprint of this dynamic complex, we first mapped the adjacent binding sites of light chains MLC1 and ELC1 on the MyoA neck (residues 775-818) using a combination of hydrogen-deuterium exchange mass spectrometry and isothermal titration calorimetry. We then determined the 1.85 Å resolution crystal structure of MLC1 in complex with its cognate MyoA peptide. Structural analysis revealed a bilobed architecture with MLC1 clamping tightly around the helical MyoA peptide, consistent with the stable 10 nm K d measured by isothermal titration calorimetry. We next showed that coordination of calcium by an EF-hand in ELC1 and prebinding of MLC1 to the MyoA neck enhanced the affinity of ELC1 for the MyoA neck 7- and 8-fold, respectively. When combined, these factors enhanced ELC1 binding 49-fold (to a K d of 12 nm). Using the full-length MyoA motor (residues 1-831), we then showed that, in addition to coordinating the neck region, ELC1 appears to engage the MyoA converter subdomain, which couples the motor domain to the neck. These data support an assembly model where staged binding events cooperate to yield high-affinity complexes that are able to maximize force transduction. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  8. Toxoplasma gondii and schizophrenia: a review of published RCTs.

    Science.gov (United States)

    Chorlton, Sam D

    2017-07-01

    Over the last 60 years, accumulating evidence has suggested that acute, chronic, and maternal Toxoplasma gondii infections predispose to schizophrenia. More recent evidence suggests that chronically infected patients with schizophrenia present with more severe disease. After acute infection, parasites form walled cysts in the brain, leading to lifelong chronic infection and drug resistance to commonly used antiparasitics. Chronic infection is the most studied and closely linked with development and severity of schizophrenia. There are currently four published randomized controlled trials evaluating antiparasitic drugs, specifically azithromycin, trimethoprim, artemisinin, and artemether, in patients with schizophrenia. No trials have demonstrated a change in psychopathology with adjunctive treatment. Published trials have either selected drugs without evidence against chronic infection or used them at doses too low to reduce brain cyst burden. Furthermore, trials have failed to achieve sufficient power or account for confounders such as previous antipsychotic treatment, sex, age, or rhesus status on antiparasitic effect. There are currently no ongoing trials of anti-Toxoplasma therapy in schizophrenia despite ample evidence to justify further testing.

  9. A unique dual activity amino acid hydroxylase in Toxoplasma gondii.

    Directory of Open Access Journals (Sweden)

    Elizabeth A Gaskell

    Full Text Available The genome of the protozoan parasite Toxoplasma gondii was found to contain two genes encoding tyrosine hydroxylase; that produces L-DOPA. The encoded enzymes metabolize phenylalanine as well as tyrosine with substrate preference for tyrosine. Thus the enzymes catabolize phenylalanine to tyrosine and tyrosine to L-DOPA. The catalytic domain descriptive of this class of enzymes is conserved with the parasite enzyme and exhibits similar kinetic properties to metazoan tyrosine hydroxylases, but contains a unique N-terminal extension with a signal sequence motif. One of the genes, TgAaaH1, is constitutively expressed while the other gene, TgAaaH2, is induced during formation of the bradyzoites of the cyst stages of the life cycle. This is the first description of an aromatic amino acid hydroxylase in an apicomplexan parasite. Extensive searching of apicomplexan genome sequences revealed an ortholog in Neospora caninum but not in Eimeria, Cryptosporidium, Theileria, or Plasmodium. Possible role(s of these bi-functional enzymes during host infection are discussed.

  10. NLRP1 Is an Inflammasome Sensor for Toxoplasma gondii

    Science.gov (United States)

    Ewald, Sarah E.; Chavarria-Smith, Joseph

    2014-01-01

    The obligate intracellular parasite Toxoplasma gondii is able to infect nearly all nucleated cell types of warm-blooded animals. This is achieved through the injection of hundreds of parasite effectors into the host cell cytosol, allowing the parasite to establish a vacuolar niche for growth, replication, and persistence. Here we show that Toxoplasma infection actives an inflammasome response in mice and rats, an innate immune sensing system designed to survey the host cytosol for foreign components leading to inflammation and cell death. Oral infection with Toxoplasma triggers an inflammasome response that is protective to the host, limiting parasite load and dissemination. Toxoplasma infection is sufficient to generate an inflammasome response in germfree animals. Interleukin 1β (IL-1β) secretion by macrophage requires the effector caspases 1 and 11, the adapter ASC, and NLRP1, the sensor previously described to initiate the inflammasome response to Bacillus anthracis lethal factor. The allele of NLRP1b derived from 129 mice is sufficient to enhance the B6 bone marrow-derived macrophage (BMDM) inflammasome response to Toxoplasma independent of the lethal factor proteolysis site. Moreover, N-terminal processing of NLRP1b, the only mechanism of activation known to date, is not observed in response to Toxoplasma infection. Cumulatively, these data indicate that NLRP1 is an innate immune sensor for Toxoplasma infection, activated via a novel mechanism that corresponds to a host-protective innate immune response to the parasite. PMID:24218483

  11. Serum Metabolic Profiling of Oocyst-Induced Toxoplasma gondii Acute and Chronic Infections in Mice Using Mass-Spectrometry

    Directory of Open Access Journals (Sweden)

    Chun-Xue Zhou

    2018-01-01

    Full Text Available Toxoplasma gondii is an obligate intracellular parasite causing severe diseases in immunocompromised individuals and congenitally infected neonates, such as encephalitis and chorioretinitis. This study aimed to determine whether serum metabolic profiling can (i identify metabolites associated with oocyst-induced T. gondii infection and (ii detect systemic metabolic differences between T. gondii-infected mice and controls. We performed the first global metabolomics analysis of mice serum challenged with 100 sporulated T. gondii Pru oocysts (Genotype II. Sera from acutely infected mice (11 days post-infection, dpi, chronically infected mice (33 dpi and control mice were collected and analyzed using LC-MS/MS platform. Following False Discovery Rate filtering, we identified 3871 and 2825 ions in ESI+ or ESI− mode, respectively. Principal Component Analysis (PCA and Partial Least Squares Discriminant Analysis (PLS-DA identified metabolomic profiles that clearly differentiated T. gondii-infected and -uninfected serum samples. Acute infection significantly influenced the serum metabolome. Our results identified common and uniquely perturbed metabolites and pathways. Acutely infected mice showed perturbations in metabolites associated with glycerophospholipid metabolism, biosynthesis of amino acid, and tyrosine metabolism. These findings demonstrated that acute T. gondii infection induces a global perturbation of mice serum metabolome, providing new insights into the mechanisms underlying systemic metabolic changes during early stage of T. gondii infection.

  12. Exosomes Secreted by Toxoplasma gondii-Infected L6 Cells: Their Effects on Host Cell Proliferation and Cell Cycle Changes.

    Science.gov (United States)

    Kim, Min Jae; Jung, Bong-Kwang; Cho, Jaeeun; Song, Hyemi; Pyo, Kyung-Ho; Lee, Ji Min; Kim, Min-Kyung; Chai, Jong-Yil

    2016-04-01

    Toxoplasma gondii infection induces alteration of the host cell cycle and cell proliferation. These changes are not only seen in directly invaded host cells but also in neighboring cells. We tried to identify whether this alteration can be mediated by exosomes secreted by T. gondii-infected host cells. L6 cells, a rat myoblast cell line, and RH strain of T. gondii were selected for this study. L6 cells were infected with or without T. gondii to isolate exosomes. The cellular growth patterns were identified by cell counting with trypan blue under confocal microscopy, and cell cycle changes were investigated by flow cytometry. L6 cells infected with T. gondii showed decreased proliferation compared to uninfected L6 cells and revealed a tendency to stay at S or G2/M cell phase. The treatment of exosomes isolated from T. gondii-infected cells showed attenuation of cell proliferation and slight enhancement of S phase in L6 cells. The cell cycle alteration was not as obvious as reduction of the cell proliferation by the exosome treatment. These changes were transient and disappeared at 48 hr after the exosome treatment. Microarray analysis and web-based tools indicated that various exosomal miRNAs were crucial for the regulation of target genes related to cell proliferation. Collectively, our study demonstrated that the exosomes originating from T. gondii could change the host cell proliferation and alter the host cell cycle.

  13. Incidence of adult brain cancers is higher in countries where the protozoan parasite Toxoplasma gondii is common

    Science.gov (United States)

    Thomas, Frédéric; Lafferty, Kevin D.; Brodeur, Jacques; Elguero, Eric; Gauthier-Clerc, Michel; Missé, Dorothée

    2012-01-01

    We explored associations between the common protozoan parasite Toxoplasma gondii and brain cancers in human populations. We predicted that T. gondii could increase the risk of brain cancer because it is a long-lived parasite that encysts in the brain, where it provokes inflammation and inhibits apoptosis. We used a medical geography approach based on the national incidence of brain cancers and seroprevalence of T. gondii. We corrected reports of incidence for national gross domestic product because wealth probably increases the ability to detect cancer. We also included gender, cell phone use and latitude as variables in our initial models. Prevalence of T. gondii explained 19 per cent of the residual variance in brain cancer incidence after controlling for the positive effects of gross domestic product and latitude among nations. Infection with T. gondii was associated with a 1.8-fold increase in the risk of brain cancers across the range of T. gondii prevalence in our dataset (4–67%). These results, though correlational, suggest that T. gondii should be investigated further as a possible oncogenic pathogen of humans.

  14. Molecular and serological prevalence of Toxoplasma gondii and Anaplasma spp. infection in goats from Chongqing Municipality, China

    Directory of Open Access Journals (Sweden)

    Zhou Zuoyong

    2018-01-01

    Full Text Available Toxoplasmosis and anaplasmosis are severe zoonotic diseases, the former caused by Toxoplasma gondii and the latter by Anaplasma spp. In the present study, 332 goat blood samples were randomly collected from Chongqing Municipality, China to screen for T. gondii and Anaplasma spp. We used a polymerase chain reaction (PCR to detect DNA, and enzyme-linked immunosorbent assay (ELISA to test for T. gondii antibodies. The prevalence of T. gondii and Anaplasma spp. was 38% and 35% respectively by PCR, and 42% for T. gondii antibodies by ELISA. The co-infection rate by T. gondii and Anaplasma was 13%, where the two predominant pathogens co-infecting were Anaplasma phagocytophilum + A. bovis (10%, followed by T. gondii + A. phagocytophilum (9.64%. While co-infection by three pathogens varied ranging from 1.81% to 5.72%, less than 1% of goats were found to be positive for four pathogens. This is the first investigation of T. gondii and Anaplasma spp. infection in goats from Chongqing.

  15. Toxoplasma gondii seroprevalence and association with equine protozoal myeloencephalitis: A case-control study of Californian horses.

    Science.gov (United States)

    James, K E; Smith, W A; Packham, A E; Conrad, P A; Pusterla, N

    2017-06-01

    While toxoplasmosis is not commonly considered a clinical disease of equines, previous seroprevalence studies have reported differing background rates of Toxoplasma gondii infection in horses globally. The objective of this study was to evaluate possible associations between T. gondii seroprevalence and clinical signs of equine protozoal myeloencephalitis (EPM) in horses. Using a case-control study design, 720 Californian horses with neurologic signs compatible with EPM were compared to healthy, non-neurologic horses for the presence of T. gondii antibodies (using indirect fluorescent antibody tests [IFAT]). Toxoplasma gondii seroprevalence among cases and controls was determined at standard serum cut-offs: 40, 80, 160, 320, and 640. At a T. gondii titre cut-off of 320, horses with clinical signs compatible with EPM had 3.55 times the odds of a seropositive test compared to those without clinical signs (Pequines. Serologic testing of cerebrospinal fluid and isolation of T. gondii in EPM suspect cases should be considered. Future studies investigating the relationship between T. gondii and EPM are warranted. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Seroprevalence and risk factors of Neospora spp. and Toxoplasma gondii infections among horses and donkeys in Nigeria, West Africa.

    Science.gov (United States)

    Bártová, Eva; Sedlák, Kamil; Kobédová, Kateřina; Budíková, Marie; Joel Atuman, Yakubu; Kamani, Joshua

    2017-09-26

    Neospora spp. and Toxoplasma gondii are considered to be a globally distributed parasites affecting wide range of warm-blooded animals. Neosporosis has caused clinical illness in horses and consumption of horse meat has been epidemiologically linked to clinical toxoplasmosis in humans. This study was conducted to determine Neospora spp. and T. gondii antibodies and risk factors of infection in horses and donkeys from three states of Nigeria. A total of 144 samples were collected from clinically healthy animals (120 horses and 24 donkeys). The sera were tested for antibodies to Neospora spp. and T. gondii by indirect fluorescence antibody test, a titer ≥ 50 was considered positive. Seroprevalence data were statistically analyzed, considering the variables of gender, age, use, state, origin of breed and type of management. Antibodies to Neospora spp. and T. gondii were detected in 8% horses with titers 50 and in 24% horses with titers 50-800, respectively. Co-infection of both parasites was proved in three horses (3%). Statistical differences were found only for T. gondii seroprevalence in horses with different use, locality, origin and management (p-value ≤ 0.05). Antibodies to T. gondii were detected in four (17%) of 24 donkeys with statistical difference (p-value ≤ 0.05) in animals of different use; antibodies to Neospora spp. were not proved in any of the donkeys. This is the first seroprevalence study of Neospora spp. and T. gondii in equids from Nigeria.

  17. Strain-specific variations in Toxoplasma gondii GRA1, GRA5, GRA6, GRA8, and GRA14

    Science.gov (United States)

    Haryati, S.; Sari, Y.; Prasetyo, A. A.; Sariyatun, R.

    2016-02-01

    Diagnosis and identification of the genetic group of T. gondii (Toxoplasma gondii) are important to control better the T. gondii infection, particularly in immunocompromised people as HIV patients. This study aimed to identify strain-specific variations in T. gondii GRA1, GRA5, GRA6, GRA8, and GRA14 in order to help design such diagnostic tool to detect and characterize the parasite. Forty-three T. gondii GRA1, GRA5, GRA6, GRA8, and GRA14 sequences deposited in GenBank were aligned. A number of positions in the gene sequences were highly conserved. All GRA sequences had strain-specific positions, however, only GRA1, GRA5, and GRA6, which contained specific variations for each T. gondii lineage. In conclusion, T. gondii GRA1, GRA5, GRA6, GRA8, and GRA14 are predicted to contain highly conserved regions and positions with strain-specific variation, which might be useful for the design of diagnostic tools detecting and distinguishing T. gondiistrains.

  18. First report of Toxoplasma gondii infection in market-sold adult chickens, ducks and pigeons in northwest China

    Directory of Open Access Journals (Sweden)

    Cong Wei

    2012-06-01

    Full Text Available Abstract Background Toxoplasma gondii infection is a global concern, affecting a wide range of warm-blooded animals and humans worldwide, including poultry. Domestic and companion birds are considered to play an important role in the transmission of T. gondii to humans and other animals. However, little information on T. gondii infection in domestic birds in Lanzhou, northwest China was available. Therefore, this study was performed to determine the seroprevalence of T. gondii infection in domestic birds in Lanzhou, northwest China. Methods In the present study, the seroprevalence of T. gondii antibodies in 413 (305 caged and 108 free-range adult chickens, 334 (111 caged and 223 free-range adult ducks and 312 adult pigeons in Lanzhou, northwest China, were examined using the modified agglutination test (MAT. Results 30 (7.26% chickens, 38 (11.38% ducks and 37 (11.86% pigeons were found to be positive for T. gondii antibodies at the cut-off of 1:5. The prevalences in caged and free-range chickens were 6.23% and 10.19% respectively, however, statistical analysis showed that the difference was not significant (P > 0.05. The seroprevalences in caged and free-range ducks were 6.31% and 13.90% respectively, but the difference was not statistically significant (P > 0.05. Conclusions The results of the present survey indicated the presence of T. gondii infection in adult chickens, ducks and pigeons sold for meat in poultry markets in Lanzhou, northwest China, which poses a potential risk for T. gondii infection in humans and other animals in this region. This is the first seroprevalence study of T. gondii infection in domestic birds in this region.

  19. First report of Toxoplasma gondii Seroprevalence in Farmed Arctic Foxes (Vulpes lagopus) in Eastern and Northeastern China.

    Science.gov (United States)

    Lou, Zhi-Long; Cong, Wei; Meng, Qing-Feng; Sun, Wu-Wen; Qin, Si-Yuan; Zhang, Xiao-Xuan; Zhu, Xing-Quan; Qian, Ai-Dong

    2015-12-01

    Until now, no information on Toxoplasma gondii seroprevalence in Arctic foxes (Vulpes lagopus) was available in China. A serological survey was undertaken to assess T. gondii seroprevalence in farmed Arctic foxes in eastern and northeastern China. Antibodies to T. gondii were examined in 1346 farmed Arctic foxes using the modified agglutination test (MAT). A total of 113 (8.39%, 95% confidence interval [CI] 6.91-9.87) serum samples were positive to T. gondii at a 1:25 cutoff. Seroprevalence of T. gondii infection in male Arctic foxes was 8.68% (95% CI 6.75-10.6), which was higher than that in the female Arctic foxes (7.95%, 95% CI 5.65-10.26). The prevalence in polar foxes was 7.07% (95% CI 5.14-8.99), which was lower than that in the blue foxes (9.75%, 95% CI 7.49-11.99). T. gondii seroprevalence in Arctic foxes in Heilongjiang, Jilin, Liaoning, and Shandong Provinces was 9.85% (95% CI 5.75-13.95), 9.21% (95% CI 5.54-12.87), 7.37% (95% CI 5.22-9.51), and 8.68% (95% CI 5.66-11.70), respectively. There were no statistically significant differences between T. gondii seroprevalence and morphs, sex, or regions of Arctic foxes in logistic regression analysis (p < 0.05). The results of the present survey indicated that T. gondii infection in farmed Arctic foxes is prevalent in China. To our knowledge, this is the first report of T. gondii seroprevalence in Arctic foxes in China.

  20. Molecular Detection and Genotypic Characterization of Toxoplasma gondii in Paraffin-Embedded Fetoplacental Tissues of Women with Recurrent Spontaneous Abortion

    Directory of Open Access Journals (Sweden)

    Amir Abdoli

    2016-11-01

    Full Text Available Background: Congenital toxoplasmosis is an important cause of spontaneous abortion worldwide. However, there is limited information on detection and genotypic characterization of Toxoplasma gondii (T. gondii in women with recurrent spontaneous abortion (RSA. The aim of this study is the molecular detection and genotypic characterization of T. gondii in formalin-fixed, paraffin-embedded fetoplacental tissues (FFPTs of women with RSA that have referred to the Avicenna Research Institute in Tehran, Iran. Materials and Methods: This experimental research was undertaken on 210 FFPTs of women with RSA. The information of the patients was collected from the archives of Avicenna Research Institute in Tehran, Iran. After DNA extraction, the presence of T. gondii was examined by nested polymerase chain reaction targeting the GRA6 gene. Genotyping was performed on positive samples using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP that targeted the GRA6 and SAG3 genes. Sequencing was conducted on two GRA6 positive samples. Results: T. gondii DNA was detected in 3.8% (8/210 of the samples. Genotyping showed that all positive samples belonged to type III of the T. gondii genotype. Sequencing two genomic DNAs of the GRA6 gene revealed 99% similarity with each other and 99-100% similarity with T. gondii sequences deposited in GenBank. There were six patients with histories of more than three abortions; one patient had a healthy girl and another patient had two previous abortions. Abortions occurred in the first trimester of pregnancy in seven patients and in the second trimester of pregnancy in one patient. Conclusion: The results of this study have indicated that genotype III is the predominant type of T. gondii in women with RSA in Tehran, Iran. Also, our findings suggest that toxoplasmosis may play a role in the pathogenesis of RSA. However, further studies are needed to elucidate a clear relationship between T. gondii

  1. Molecular Detection and Genotypic Characterization of Toxoplasma gondii in Paraffin-Embedded Fetoplacental Tissues of Women with Recurrent Spontaneous Abortion

    Science.gov (United States)

    Abdoli, Amir; Dalimi, Abdolhossein; Soltanghoraee, Haleh; Ghaffarifar, Fatemeh

    2017-01-01

    Background Congenital toxoplasmosis is an important cause of spontaneous abortion worldwide. However, there is limited information on detection and genotypic characterization of Toxoplasma gondii (T. gondii) in women with recurrent spontaneous abortion (RSA). The aim of this study is the molecular detection and genotypic characterization of T. gondii in formalin-fixed, paraffin-embedded fetoplacental tissues (FFPTs) of women with RSA that have referred to the Avicenna Research Institute in Tehran, Iran. Materials and Methods This experimental research was undertaken on 210 FFPTs of women with RSA. The information of the patients was collected from the archives of Avicenna Research Institute in Tehran, Iran. After DNA extraction, the presence of T. gondii was examined by nested polymerase chain reaction targeting the GRA6 gene. Genotyping was performed on positive samples using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) that targeted the GRA6 and SAG3 genes. Sequencing was conducted on two GRA6 positive samples. Results T. gondii DNA was detected in 3.8% (8/210) of the samples. Genotyping showed that all positive samples belonged to type III of the T. gondii genotype. Sequencing two genomic DNAs of the GRA6 gene revealed 99% similarity with each other and 99-100% similarity with T. gondii sequences deposited in GenBank. There were six patients with histories of more than three abortions; one patient had a healthy girl and another patient had two previous abortions. Abortions occurred in the first trimester of pregnancy in seven patients and in the second trimester of pregnancy in one patient. Conclusion The results of this study have indicated that genotype III is the predominant type of T. gondii in women with RSA in Tehran, Iran. Also, our findings suggest that toxoplasmosis may play a role in the pathogenesis of RSA. However, further studies are needed to elucidate a clear relationship between T. gondii infection and RSA. PMID

  2. Occurrence of infection by Toxoplasma gondii in slaughtered swine in the northwestern region of Paraná, Brazil

    Directory of Open Access Journals (Sweden)

    Hannah Lia Ettiene Peruch Lemos dos Santos

    2015-07-01

    Full Text Available This study aimed to determine the prevalence of Toxoplasma gondii in swine slaughtered in Iporã, Northwest Paraná state. Blood samples were obtained from 500 finishing swine. All animals were raised under intensive farming; the blood samples were analyzed using the immunofluorescence antibody test (IFAT. Animals with titers of ?64 were considered positive for T. gondii infection. Of the tested samples, 63 (12.6% were positive by IFAT; 58 (92.06% of these showed titers of 64 (4.7%, with titers 256 and two (3.1% titers of 1024. These pigs might be considered a source of T. gondii infection for humans

  3. Seroprevalence and correlates of Toxoplasma gondii infection in Yoremes (Mayos) in Mexico: a cross-sectional study.

    Science.gov (United States)

    Alvarado-Esquivel, Cosme; Rascón-Careaga, Antonio; Hernández-Tinoco, Jesús; Corella-Madueño, María Alba Guadalupe; Sánchez-Anguiano, Luis Francisco; Aldana-Madrid, María Lourdes; Almada-Balderrama, Gerardo Javier; Nuñez-Aguirre, Alan Daniel; Liesenfeld, Oliver

    2016-05-12

    We sought to determine the prevalence of anti-Toxoplasma gondii antibodies in Yoremes and to identify associations of T. gondii exposure with sociodemographic, clinical and behavioural characteristics of Yoremes. A cross-sectional survey. Yoremes were enrolled in the locality of Tierra Blanca in the municipality of Navojoa in Sonora State, Mexico. We studied 200 Yoremes (Mayos); they are an indigenous ethnic group living in a coastal region in northwestern Mexico. We assessed the prevalence of anti-Toxoplasma IgG and IgM antibodies in participants using enzyme-linked immunoassays. We used a standardised questionnaire to obtain the characteristics of Yoremes. The association of T. gondii exposure and Yoremes' characteristics was assessed by bivariate and multivariate analyses. Of the 200 Yoremes studied (mean age: 31.50±18.43 years), 26 (13.0%) were positive for anti-T. gondii IgG antibodies and 19 (73.1%) of them were also positive for anti-T. gondii IgM antibodies. Seroprevalence of T. gondii infection did not vary with sex, educational level, occupation or socioeconomic status. In contrast, multivariate analysis of sociodemographic and behavioural characteristics showed that T. gondii exposure was associated with increasing age (OR=1.02; 95% CI 1.00 to 1.04; p=0.03) and consumption of squirrel meat (OR=4.99; 95% CI 1.07 to 23.31; p=0.04). Furthermore, seroprevalence of T. gondii infection was significantly higher in Yoremes with a history of lymphadenopathy (p=0.03) and those suffering from frequent abdominal pain (p=0.03). In women, T. gondii exposure was associated with a history of caesarean sections (p=0.03) and miscarriages (p=0.02). We demonstrate, for the first time, serological evidence of T. gondii exposure among Yoremes in Mexico. Results suggest that infection with T. gondii might be affecting the health of Yoremes. Results may be useful for an optimal design of preventive measures against T. gondii infection. Published by the BMJ Publishing Group

  4. Avidity of IgG antibodies against excreted/secreted antigens of Toxoplasma gondii: immunological marker for acute recent toxoplasmosis Avidez de anticorpos IgG anti-antígeno de secreção e excreção de Toxoplasma gondii: marcador imunológico de toxoplasmose aguda recente

    Directory of Open Access Journals (Sweden)

    Patrícia Regina Barboza Araújo

    2008-04-01

    Full Text Available Detection of anti-toxoplasma IgM antibodies has frequently been used as a serological marker for diagnosing recently acquired toxoplasmosis. However, the persistence of these antibodies in some patients has complicated the interpretation of serological results when toxoplasmosis is suspected. The purpose of the present study was to evaluate the avidity of IgG antibodies against excreted/secreted antigens of Toxoplasma gondii by means of immunoblot, to establish a profile for acute recent infection in a single serum sample and confirm the presence of residual IgM antibodies obtained in automated assays. When we evaluated the avidity of IgG antibodies against excreted/secreted antigens of Toxoplasma gondii by means of immunoblot, we observed phase-specific reactivity, i.e. cases of acute recent toxoplasmosis presented low avidity and cases of non-acute recent toxoplasmosis presented high avidity towards the 30kDa protein fraction, which probably corresponds to the SAG-1 surface antigen. Our results suggest that the avidity of IgG antibodies against excreted/secreted antigens of Toxoplasma gondii is an important immunological marker for distinguishing between recent infections and for determining the presence of residual IgM antibodies obtained from automated assays.A detecção de anticorpos IgM antitoxoplasma tem sido freqüentemente utilizada como marcador sorológico para o diagnóstico de toxoplasmose de aquisição recente. Entretanto, a persistência destes anticorpos em alguns pacientes tem complicado a interpretação dos resultados sorológicos quando a toxoplasmose é suspeitada. A proposta deste trabalho foi avaliar a avidez de anticorpos IgG contra antígenos de secreção e excreção de Toxoplasma gondii por immunoblot, para estabelecer um perfil de infecção recente aguda em uma única amostra de soro e confirmar a presença de anticorpos IgM residuais obtidos nos testes automatizados. Quando a avidez de anticorpos IgG contra ant

  5. Macrophages facilitate the excystation and differentiation of Toxoplasma gondii sporozoites into tachyzoites following oocyst internalization

    Science.gov (United States)

    Toxoplasma gondii is a common parasite of humans and domestic animals, which is transmitted via oocysts in cat faeces or tissue cysts in contaminated meat. The oocyst and sporocyst walls are multilayered polymeric structures that protect the infective sporozoites from deleterious physical and chemic...

  6. SAG2 locus genotyping of Toxoplasma gondii in meat products of ...

    African Journals Online (AJOL)

    T. gondii DNA was detected in 16.6, 19.1, 15 and 56.6%, in salami, sausages, and hamburger and kebab samples, respectively. Genotyping by restriction fragment length polymorphism (RFLP) analysis of SAG2 locus revealed that all of the samples belonged to genotype I. The detection of the parasite in uncooked meat ...

  7. The sero-prevalence of Toxoplasma gondii in British marine mammals

    Directory of Open Access Journals (Sweden)

    Dan Forman

    2009-03-01

    Full Text Available Serum samples from 101 stranded or bycatch cetaceans from British waters were screened for Toxoplasma gondii-specific antibodies using the Sabin Feldman Dye Test. Relatively high seropositivity was recorded in short-beaked Delphinus delphis and this study presents the first documented case of Toxoplasma in a humpback whale Megaptera novaeangliae.

  8. Cats and Goat Whey Associated with Toxoplasma gondii Infection in Pigs

    NARCIS (Netherlands)

    Meerburg, B.G.; Riel, van J.W.; Cornelissen, J.B.W.J.; Kijlstra, A.; Mul, M.F.

    2006-01-01

    In organic livestock production systems, farm-management factors are thought to play an important role in the on-farm prevalence of Toxoplasma gondii. Serological results and the results of an HACCP analysis were combined to determine important risk factors for the prevalence of this protozoan

  9. Seroepidemiology of Toxoplasma gondii infection in women from the North of Portugal in their childbearing years

    Science.gov (United States)

    Seroprevalence of Toxoplasma gondii infection and associated risk factors were investigated in 401 women of childbearing age from the North of Portugal. Among the 98 (24.4%) seropositive women, 92 (93.9%) were detected as positive only for imunoglobulin (Ig) G, two women (2.0%) were positive only fo...

  10. Prevalence of antibodies to Leishmania infantum and Toxoplasma gondii in horses from the north of Portugal

    Science.gov (United States)

    Background Leishmania infantum and Toxoplasma gondii are protozoa with zoonotic and economic importance. Prevalences of antibodies to these agents were assessed in 173 horses from the north of Portugal. Findings Antibodies to L. infantum were detected by the direct agglutination test (DAT); seven (...

  11. Prevalence of antibodies to Toxoplasma gondii in dogs from northeastern Portugal

    Science.gov (United States)

    Prevalence of antibodies to Toxoplasma gondii was investigated in 673 domestic dogs from northeastern Portugal, by using the modified agglutination test (MAT) with 1:20 as cut-off for seropositivity; antibodies were found in 256 dogs (38.0%). Differences between seroprevalence levels in males (36.7%...

  12. Seroprevalence of Toxoplasma gondii in American Black Bears ( Ursus americanus ) of the Central Appalachians, USA.

    Science.gov (United States)

    Cox, John J; Murphy, Sean M; Augustine, Ben C; Guthrie, Joseph M; Hast, John T; Maehr, Sutton C; McDermott, Joseph

    2017-07-01

    We assessed Toxoplasma gondii seroprevalence in 53 free-ranging American black bears ( Ursus americanus ) in the Central Appalachian Mountains, US. Seroprevalence was 62% with no difference between males and females or between juvenile and adult bears. Wildlife agencies should consider warnings in hunter education programs to reduce the chances for human infection from this source.

  13. Comparison of methods for detection of Toxoplasma gondii in tissues of naturally exposed pigs.

    Science.gov (United States)

    Bezerra, Rodrigo A; Carvalho, Fábio S; Guimarães, Luciana A; Rocha, Daniele S; Silva, Fabiana L; Wenceslau, Amauri A; Albuquerque, George R

    2012-02-01

    This study aimed to compare the sensitivity of five diagnostic methods commonly used for the detection of Toxoplasma gondii in tissues of naturally infected pigs. We purchased 20 heads of pigs in butcher shops in the city of Ilhéus, Bahia. Brain and tongue fragments were taken from each animal for the performance of PCR against T. gondii. The rest of these two tissues were processed and inoculated into three mice. These rodents were observed for 42 days and euthanized. We prepared slides with brain and lungs of each mouse for the visualization of T. gondii. From the tissues of mice, we carried out polymerase chain reaction (PCR), histopathology, and immunohistochemistry in an attempt to identify the parasite. The PCR direct from the tissue of pigs showed 10% (2/20) of positive samples, all from the brain. PCR in tissue from mice found that 55% (11/20) of pigs were positive: 55% (11/20) and 45% (9/20) for brains and tongues, respectively. Mice were inoculated with material obtained from the samples and examined by various methods for resulting Toxoplasma infection (bioassay). Cyst detection in bioassay mice identified 25% (5/20) and immunohistochemistry 30% (6/20) of the samples pigs as positive for T. gondii. Histopathology of mice tissue could not detect parasite; only suggestive pathological changes such as inflammation with foci of necrosis were seen. The results indicated PCR of mice tissue as the most sensitive among those tested.

  14. Toxoplasma gondii in stranded marine mammals from the North Sea and Eastern Atlantic Ocean

    NARCIS (Netherlands)

    Velde, van de Norbert; Devleesschauwer, Brecht; Leopold, Mardik; Begeman, Lineke; IJsseldijk, Lonneke; Hiemstra, Sjoukje; IJzer, Jooske; Brownlow, Andrew; Davison, Nicholas; Haelters, Jan

    2016-01-01

    The occurrence of the zoonotic protozoan parasite Toxoplasma gondii in marine mammals remains a poorly understood phenomenon. In this study, samples from 589 marine mammal species and 34 European otters (Lutra lutra), stranded on the coasts of Scotland, Belgium, France, The Netherlands and

  15. Uptake and transmission of Toxoplasma gondii oocysts by migratory filter-feeding fish

    Science.gov (United States)

    Toxoplasma gondii is a ubiquitous parasitic protozoan known to cause disease and death in warm-blooded animals. Bottlenose dolphins, walruses, sea otters, and other marine animals worldwide have died from toxoplasmosis, but the source of this parasite in the marine environment h...

  16. Canine distemper virus and Toxoplasma gondii co-infection in dogs with neurological signs

    Directory of Open Access Journals (Sweden)

    D.M. Aguiar

    2012-02-01

    Full Text Available O presente estudo relata a ocorrência de co-infecção entre o vírus da cinomose canina (CDV e Toxoplama gondii em cães com sinais neurológicos. Amostras de soro e tecido nervoso (pos-mortem de 21 cães, suspeitos de cinomose canina foram analisadas pela Reação de Imunofluorecência indireta (RIFI para pesquisa de anticorpos contra T. gondii e N. caninum e por RT-PCR para CDV. Dezessete (80,9% cães foram positivos para o CDV pela RT-PCR e 8 (38,1% foram positivos para anticorpos contra T. gondii. Sete cães (41,1% apresentaram-se positivos para ambos agentes, caracterizando processo de co-infecção. Somente 1 (4,7% cão foi soropositivo para N. caninum (RIFI=100, entretanto este mesmo animal foi positivo para T. gondii (RIFI=4096 e para CDV (RT-PCR.

  17. Toxoplasma gondii infection induces dendritic retraction in basolateral amygdala accompanied by reduced corticosterone secretion

    Directory of Open Access Journals (Sweden)

    Rupshi Mitra

    2013-03-01

    Pathological anxiety is thought to reflect a maladaptive state characterized by exaggerated fear. Naturally occurring perturbations that reduce fear can be crucial in the search for new treatments. The protozoan parasite Toxoplasma gondii invades rat brain and removes the fear that rats have of cat odors, a change believed to be parasitic manipulation of host behavior aimed at increasing parasite transmission. It is likely that mechanisms employed by T. gondii can be used as a heuristic tool to understand possible means of fear reduction in clinical settings. Male Long-Evans rats were infected with T. gondii and compared with sham-infected animals 8 weeks after infection. The amount of circulating plasma corticosterone and dendritic arborization of basolateral amygdala principal neurons were quantified. Previous studies have shown that corticosterone, acting within the basolateral amygdala, enhances the fear response to environmental stimuli. Here we show that T. gondii infection causes a dendritic retraction in basolateral amygdala neurons. Such dendritic retraction is accompanied by lower amounts of circulating corticosterone, both at baseline and when induced by an aversive cat odor. The concerted effects of parasitism on two pivotal physiological nodes of the fear response provide an animal model relevant to interactions between stress hormones and amygdalar plasticity.

  18. Behavioural and biochemical profiles in rats infected with Toxoplasma gondii or lipopolysaccharide: animal models of schizophrenia

    Czech Academy of Sciences Publication Activity Database

    Tejkalová, H.; Kodym, P.; Kačer, P.; Klaschka, Jan; Horáček, J.

    2013-01-01

    Roč. 24, e-Suppl. 1 (2013), e22 ISSN 0955-8810. [Biennal meeting of the EBPS /15./. 06.09.2013-09.09.2013, La Rochelle] Institutional support: RVO:67985807 Keywords : animal models * schizophrenia * behaviour * LPS * Toxoplasma gondii Subject RIV: FH - Neurology

  19. Association of Toxoplasma gondii infection with schizophrenia and its relationship with suicide attempts in these patients.

    Science.gov (United States)

    Ansari-Lari, Maryam; Farashbandi, Hassan; Mohammadi, Fahimeh

    2017-10-01

    To investigate the association between schizophrenia and Toxoplasma gondii, and to assess the association of infection with suicide attempts and age of onset of schizophrenia in these patients. Case-control study Fars Province, southern Iran. Cases were individuals with psychiatric diagnosis of schizophrenia as per Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) criteria. Controls were healthy blood donors, frequency-matched with patients according to age and sex. For the detection of IgG antibodies, enzyme-linked immunosorbent assay (ELISA) was used. Data about demographic information in all subjects and duration of illness and history of suicide attempts in patients with schizophrenia were collected using a brief questionnaire and hospital records. Chi-square test and multivariable logistic regression were used for statistical analyses. Among 99 cases, 42 individuals (42%) were positive for T. gondii antibody, vs. 41 (27%) among 152 controls (OR = 2, 95% CI: 1.2-3.4, P = 0.012). We compared the suicide attempts in patients with schizophrenia based on their T. gondii serologic status. There was a lower rate of suicide attempts in seropositive male patients than seronegative ones (OR = 0.3, 95% CI: 0.1-0.97, P = 0.04). Age of onset of schizophrenia did not differ between T. gondii-infected and non-infected patients. These findings may have implications for schizophrenia and suicide prevention programmes. However, clearly further studies are required to confirm them. © 2017 John Wiley & Sons Ltd.

  20. Toxoplasma gondii infection induces suppression in a mouse model of allergic airway inflammation.

    Directory of Open Access Journals (Sweden)

    Ignacio M Fenoy

    Full Text Available Allergic asthma is an inflammatory disorder characterized by infiltration of the airway wall with inflammatory cells driven mostly by activation of Th2-lymphocytes, eosinophils and mast cells. There is a link between increased allergy and a reduction of some infections in Western countries. Epidemiological data also show that respiratory allergy is less frequent in people exposed to orofecal and foodborne microbes such as Toxoplasma gondii. We previously showed that both acute and chronic parasite T. gondii infection substantially blocked development of airway inflammation in adult BALB/c mice. Based on the high levels of IFN-γ along with the reduction of Th2 phenotype, we hypothesized that the protective effect might be related to the strong Th1 immune response elicited against the parasite. However, other mechanisms could also be implicated. The possibility that regulatory T cells inhibit allergic diseases has received growing support from both animal and human studies. Here we investigated the cellular mechanisms involved in T. gondii induced protection against allergy. Our results show for the first time that thoracic lymph node cells from mice sensitized during chronic T. gondii infection have suppressor activity. Suppression was detected both in vitro, on allergen specific T cell proliferation and in vivo, on allergic lung inflammation after adoptive transference from infected/sensitized mice to previously sensitized animals. This ability was found to be contact-independent and correlated with high levels of TGF-β and CD4(+FoxP3(+ cells.

  1. Conjugated Linoleic Acid Stimulates Apoptosis in RH and Tehran Strains of Toxoplasma gondii, in Vitro.

    Directory of Open Access Journals (Sweden)

    Jebreil Shamseddin

    2015-06-01

    Full Text Available The aim of this study was to evaluate the effects of conjugated linoleic acid (CLA on apoptosis of tachyzoites of T. gondii, RH strain (type I and the cyst-forming Tehran strain (type II in vitro.Toxoplasma strains were injected into the peritoneal cavity of BALB/c mice. The Tehran strain forms cysts in the brain of mice. Bradyzoites within the cysts are reactivated to proliferative tachyzoites, by dexamethasone. Tachyzoites were aspirated from the peritoneum of infected mice, and the percentage of viable parasites was estimated with trypan blue staining. Tachyzoites were inoculated into HeLa cells cultivated in DMEM medium. Different concentrations of CLA were evaluated on T. gondii in HeLa cells by the tetrazolium (MTT colorimetric assay. Differentiation between apoptosis and cell death was determined by flow cytometry using Annexin V and propidium iodide (PI double staining. The statistical analysis performed by GraphPad Prism version 6.00.CLA induces apoptosis in virulent (RH and avirulent (Tehran strains of T. gondii. The results of MTT indicated that CLA could decrease the proliferation of tachyzoites of both strains in HeLa cells.Conjugated linoleic acid has anti-toxoplasmacidal activity on tachyzoites of T. gondii. Therefore, we recommended further studies on this component in order to achieve a new drug against the parasite.

  2. Red foxes (Vulpes vulpes) in Romania are carriers of Toxoplasma gondii but not Neospora caninum.

    Science.gov (United States)

    Şuteu, Ovidiu; Mihalca, Andrei Daniel; Paştiu, Anamaria Ioana; Györke, Adriana; Matei, Ioana Adriana; Ionică, Angela; Balea, Anamaria; Oltean, Miruna; D'Amico, Gianluca; Sikó, Sándor Barabási; Ionescu, Dan; Gherman, Călin Mircea; Cozma, Vasile

    2014-07-01

    Brain samples from 182 red foxes (Vulpes vulpes) from Romania were examined using a standard PCR technique. Results provide evidence of Toxoplasma gondii (11 foxes=6.0%) and Neospora caninum (1 fox=0.5%) DNA in red foxes from Romania. No coinfections were found.

  3. Serological Evidence of Toxoplasma gondii infection in five species of bats in China

    Science.gov (United States)

    Toxoplasma gondii is an obligate intracellular protozoan parasite which can infect almost all warm-blooded animals and humans with a worldwide distribution. Bats are reservoirs for an increasing number of emerging zoonotic viruses, such as henipaviruses and severe acute respiratory syndrome (SARS) c...

  4. Seroprevalence of Toxoplasma gondii infection in goats and sheep in Zimbabwe

    DEFF Research Database (Denmark)

    Hove, T.; Lind, Peter; Mukaratirwa, S.

    2005-01-01

    seroprevalences found in Natural regions IIb and III are likely to be linked to the existence of more households and hence the possibility of a higher concentration of domestic cats that increases the chances of environmental contamination with their faeces harbouring T. gondii oocysts. The seroprevalence rate...

  5. An experimental Toxoplasma gondii dose response challenge model to study therapeutic or vaccine efficacy in cats

    NARCIS (Netherlands)

    Cornelissen, J.B.W.J.; Giessen, van der J.W.B.; Takumi, K.; Teunis, P.F.M.; Wisselink, H.J.

    2014-01-01

    High numbers of Toxoplasma gondii oocysts in the environment are a risk factor to humans. The environmental contamination might be reduced by vaccinating the definitive host, cats. An experimental challenge model is necessary to quantitatively assess the efficacy of a vaccine or drug treatment.

  6. Lack of viable parasites in cured 'Parma Ham' (PDO), following experimental Toxoplasma gondii infection of pigs.

    Science.gov (United States)

    Genchi, Marco; Vismarra, Alice; Mangia, Carlo; Faccini, Silvia; Vicari, Nadia; Rigamonti, Sara; Prati, Paola; Marino, Anna Maria; Kramer, Laura; Fabbi, Massimo

    2017-09-01

    Twelve Large White pigs were experimentally infected with 1000 Toxoplasma gondii oocysts/each. Serology was carried out at different time points post infection (p.i.) and animals were slaughtered at four months p.i. One of two thighs was examined for T. gondii infection status by PCR and bioassay in mice. The other thigh was processed for Parma ham production. Four thighs were examined after twelve months of curing, four after fourteen months and four were examined after sixteen months. Cured hams were analyzed by PCR, bioassay and in-vitro cultivation on Vero cells followed by real-time PCR. Pigs seroconverted from day 21 p.i. Bioassays were positive for all fresh thighs, but negative for cured hams. PCR was positive for parasite DNA from most thighs both at slaughter and post curing, but parasite growth was not observed following in vitro cultivation and real-time PCR. Results indicate that the curing process of Parma Ham (PDO), when carried out according to the Parma Ham consortium regulations, can inactivate T. gondii tissue cysts. Results would suggest that food-borne transmission of T. gondii to consumers from Parma ham can be excluded. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Seroprevalence of Toxoplasma gondii in dogs of riverside communities of Mato Grosso Pantanal, Brazil.

    Science.gov (United States)

    Rodrigues, Juliana Yuki; Almeida, Arleana do Bom Parto Ferreira de; Boa Sorte, Eveline da Cruz; Gasparetto, Naiani Domingos; Cruz, Felipe Augusto Constantino Seabra da; Sousa, Valéria Régia Franco

    2016-01-01

    Toxoplasma gondii is an intracellular protozoan with worldwide distribution and dogs act as sentinels of human infection. This search aimed to determine the occurrence of antibodies against T. gondii in dogs of the communities on the Cuiabá River, Mato Grosso and variables associated with infection. The dogs of the riverside communities in Cuiabá River, which includes Barranco Alto, Praia do Poço, Engenho Velho, Varginha, Bom Sucesso, Passagem da Conceição and São Gonçalo Beira Rio, were evaluated for the presence of T. gondii antibodies by indirect immunofluorescence antibody test (IFAT). The prevalence and factors associated with infection were calculated by chi-squared test (χ2) or Fisher's exact test, and univariate and multiple analysis. Of the 248 dogs surveyed, 107 (43.1%) were seropositive for T. gondii. The seroprevalence ranged from 25.6% to 64.3%. There was no statistically significant difference between the communities studied (p > 0.05). As for the associated factors, the only statistically significant factor was that of dogs living with cats (p = 0.02), with approximately twice the risk of acquiring infection. In conclusion, the seroprevalence in dogs of riverside communities in the Baixada Cuiabana demonstrated that high rates of infection, being the factor associated with infection, contact with domestic cats.

  8. Cytomegalovirus and Toxoplasma gondii seroprevalence in a Brazilian liver transplant waiting

    Directory of Open Access Journals (Sweden)

    R. A. M. B. Almeida

    2007-01-01

    Full Text Available Cytomegalovirus (CMV disease is a major cause of morbidity and mortality in solid organ transplantation. Disseminated toxoplasmosis after liver transplantation is a rare but fatal event. Serologic screening of the donor and the recipient is essential to prophylactic management, early diagnosis and therapeutic strategies to minimize the consequences of these infections. The aim of the present study was to determine the seroprevalence of CMV and Toxoplasma gondii (TG in a Brazilian liver transplant waiting list (LTWL. Serological data were collected from 44 candidates on the LTWL between May 2003 and November 2004. Serological investigation of antibodies IgM and IgG against CMV (anti-CMV and TG (anti-T. gondii was performed using fluorometry commercial kits. IgG anti-CMV was positive in 37 patients (94.9% out of 39 available results. There were not IgM anti-CMV positive results. Out of 36 analyzed patients, 22 (61.1% presented positive IgG anti-T. gondii and none had positive IgM anti-T. gondii. The high CMV seroprevalence among our LTWL reinforces the need for appropriate protocols to avoid related complications, like reactivation and superinfection by CMV. Environmental and drug prophylactic strategies against primary infection and reactivation, as well as early diagnosis and treatment of toxoplasmosis complications, are essential for the good outcome of transplant patients.

  9. BEHAVIORAL AND MEMORY CHANGES IN Mus musculus COINFECTED BY Toxocara canis AND Toxoplasma gondii

    Directory of Open Access Journals (Sweden)

    Flávia Motta Corrêa

    2014-07-01

    Full Text Available Several researchers have stated that parasites can alter the behavior of their hosts, in order to increase the transmission rate, principally when prey-predator relationships are a reliable way of infection transmission. The aim of this study was to verify the occurrence of changes in anxiety and short-term memory patterns in experimentally infected Mus musculus by Toxocara canis and/or Toxoplasma gondii. Forty male Mus musculus (Balb/c eight-week-old were divided into four groups of 10 mice each. One group was infected with 300 eggs of Toxocara canis; a second group was submitted to infection with 10 cysts of Toxoplasma gondii; a third group was concomitantly infected with both parasites with the same inoculums and the last group was maintained without infection. The anxiety levels were evaluated using an elevated plus maze and an actometer; the short-term memory was determined by a two-way active avoidance equipment. The determination of anxiety levels were conducted 40 and 70 days after infection and the short-term memory was evaluated 140 days after infection. Mice chronically infected by Toxoplasma gondii showed impaired learning and short-term memory, but no significant differences were found in mice infected by Toxocara canis or concomitantly infected by Toxocara canis and Toxoplasma gondii when compared to non infected mice.

  10. Behavioral and memory changes in Mus musculus coinfected by Toxocara canis and Toxoplasma gondii.

    Science.gov (United States)

    Corrêa, Flávia Motta; Chieffi, Pedro Paulo; Lescano, Susana A Zevallos; Santos, Sergio Vieira dos

    2014-01-01

    Several researchers have stated that parasites can alter the behavior of their hosts, in order to increase the transmission rate, principally when prey-predator relationships are a reliable way of infection transmission. The aim of this study was to verify the occurrence of changes in anxiety and short-term memory patterns in experimentally infected Mus musculus by Toxocara canis and/or Toxoplasma gondii. Forty male Mus musculus (Balb/c) eight-week-old were divided into four groups of 10 mice each. One group was infected with 300 eggs of Toxocara canis; a second group was submitted to infection with 10 cysts of Toxoplasma gondii; a third group was concomitantly infected with both parasites with the same inoculums and the last group was maintained without infection. The anxiety levels were evaluated using an elevated plus maze and an actometer; the short-term memory was determined by a two-way active avoidance equipment. The determination of anxiety levels were conducted 40 and 70 days after infection and the short-term memory was evaluated 140 days after infection. Mice chronically infected by Toxoplasma gondii showed impaired learning and short-term memory, but no significant differences were found in mice infected by Toxocara canis or concomitantly infected by Toxocara canis and Toxoplasma gondii when compared to non infected mice.

  11. Antibody Prevalence and Risk Factors for Toxoplasma gondii Infection in Women from Multan, Pakistan.

    Science.gov (United States)

    Nazir, M M; Akhtar, M; Maqbool, A; Waheed, A; Sajid, M A; Ali, M A; Oneeb, M; Alam, M A; Ahmad, A N; Nazir, N; Fatima, S; Lindsay, D S

    2017-11-01

    Toxoplasma gondii infections are prevalent in humans and warm-blooded animals. Maternal infections during pregnancy may have devastating consequences for transplacentally infected neonates. This study was conducted to examine the seroprevalence of antibodies to T. gondii in pregnant women of childbearing age and determine risk factors associated with pregnancy history, pet ownership, social and cultural factors at Nishtar Hospital, Multan. Samples were collected from 403 women and examined using a commercially available enzyme-linked immunosorbent assay (ELISA). The overall prevalence of antibodies to T. gondii was 17.6% (71) in the 403 samples collected from women. Antibodies to T. gondii were present in 19.4% (45) of 232 pregnant women and 15.2% (26) of the samples from 171 non-pregnant women. This study identified miscarriage history, pet ownership, type of residence, marital status, source of drinking water and eating habits as significant (P  0.05) in women from different ethnic groups based upon lifestyle and culture. © 2017 Blackwell Verlag GmbH.

  12. 97 original article toxoplasma gondii infection in hiv/aids: prevalence ...

    African Journals Online (AJOL)

    BACKGROUND: Toxoplasmosis is an infection caused by the protozoan Toxoplasma gondii. It is common in severely immune- compromised persons. OBJECTIVE: To determine the .... or eating food that has been cross- contaminated; ingesting of oocysts from soil through gardening, handling and eating unwashed ...

  13. Infectivity of cysts of the ME-49 Toxoplasma gondii strain in bovine milk and homemade cheese

    Directory of Open Access Journals (Sweden)

    Hiramoto RM

    2001-01-01

    Full Text Available OBJECTIVE: Analyze the infectivity and storage resistance of cysts of the ME-49 strain of Toxoplasma gondii in artificially infected bovine milk and homemade fresh cheese. METHODS: Pasteurized bovine milk was infected with 10 cysts/ml of the ME-49 strain of T.gondii and inoculated in different groups of mice, immediately or after storage at 4ºC for 5, 10 and 20 days. Homemade fresh cheese was prepared with artificially infected milk, and also tested in groups of mice, using the same storage process. Infection was identified by the presence of cysts in the brain or serological testing in challenged mice after 5 weeks, confirmed by Western Blot and histology. RESULTS: The infectivity of cysts of the ME-49 strain of T.gondii was maintained in the milk even after storage for 20 days at refrigerator temperatures. Cysts were also able to survive the production process of homemade fresh cheese and storage for a period of 10 days in the same conditions. CONCLUSIONS: These data demonstrated that milk and dairy products could be an important source of T.gondii in human contamination, reinforcing the importance of milk pasteurization before any processing or ingestion.

  14. Serological Survey and Factors Associated with Toxoplasma gondii Infection in Domestic Goats in Myanmar

    Directory of Open Access Journals (Sweden)

    Saw Bawm

    2016-01-01

    Full Text Available Goat farming is important for the livelihood of millions of rural people because it contributes to food security and creation of assets. However, infection of goats with Toxoplasma gondii could be a source of parasite transmission to humans. The information on T. gondii infection of goat was not reported yet in Myanmar. A total of 119 goat serum samples were collected from three cities in the central region of Myanmar for T. gondii antibody survey. With the occurrence value obtained in this first study, a second one, more complete, with larger number (162 of animals and properties, was carried out and the risk factors and prevalence were determined. In both studies the samples were analyzed by the LAT. Of these, 32 (11.4% samples were showed to be positive. The infection was associated with the presence of cats at the farm (odds ratio [OR] = 4.66, 95% confidential interval [CI] = 1.03–21.06, farming with different animal species (sheep, cattle, and pigs (OR = 4.33, 95% CI = 1.57–11.94, and farming without good management practices (OR = 0.23, 95% CI = 0.06–0.83. This is the first T. gondii prevalence study in goats in the country.

  15. Frequency of Toxoplasma gondii in the retina in eye banks in Brazil.

    Science.gov (United States)

    Costa, Deise F; Nascimento, Heloisa; Sutili, Aline; Nobrega, Fernando A J; Fowler, Flavio; Nobrega, Mario Junqueira; Garrido, Cristina; de Oliveira Dias, Janaina; Adán, Consuelo B D; Rizzo, Luiz Vicente; Silveira, Claudio; Belfort, Rubens; Commodaro, Alessandra G

    2017-07-01

    Ocular toxoplasmosis is the main cause of posterior uveitis worldwide frequently leading to vision loss. In Brazil, the seroprevalence of Toxoplasma gondii infection ranges from 50 to 80% depending of the region studied. The frequency of toxoplasmic retinal scar may reach 18% of the adults in the South of Brazil. Our goal was to determine the frequency of T. gondii DNA in retinas from eye banks from different regions in Brazil. A total of 162 eyes were obtained from eye banks in Manaus (n = 60), Sao Paulo (n = 60), Chapeco (n = 26), and Joinville (n = 16). The retinas were macroscopically analyzed and collected for DNA extraction. Real-time PCR (qPCR) was performed using the T. gondii B1 marker. By qPCR, a higher frequency of T. gondii DNA in the retinas from the eye bank of Joinville (25%) was found when compared to Manaus (5%). The retinas from Sao Paulo and Chapeco were qPCR negative. Clinical examination determined the retina lesions to be compatible with toxoplasmosis in the following frequencies: Joinville (62.5%), Manaus (10%), Sao Paulo (6.7%), and Chapeco (15.4%).

  16. Molecular prevalence of Toxoplasma gondii DNA in goats' milk and seroprevalence in Northwest Tunisia.

    Science.gov (United States)

    Amairia, Safa; Rouatbi, Mariem; Rjeibi, Mohamed R; Nouasri, Hanen; Sassi, Limam; Mhadhbi, Moez; Gharbi, Mohamed

    2016-08-01

    Toxoplasmosis is a worldwide zoonosis with high impact on human and animal health. Consumption of unpasteurized milk is a risk factor of human toxoplasmosis. The aim of this study was to estimate the seroprevalence and molecular prevalence of T. gondii in goats' milk in Northwest of Tunisia (Jendouba Governorate). A total number of 77 blood samples were collected from six herds were screened with a commercial ELISA kit for T. gondii antibodies. For the same goats' samples, a nested PCR was performed to detect T. gondii DNA in milk. The seroprevalence of T. gondii infection was 31.2% (±0.05) while the molecular prevalence of this parasite in milk was estimated to 7.8% (±0.03). A very low value of kappa showed that there is not agreement between seroprevalence and parasite prevalence in milk. These results suggest that the consumption of raw milk from naturally infected goats is a potential source of human infection. An extension programme should be implemented to decrease related to goats' raw milk consumption.

  17. Isolation of Toxoplasma gondii in a pig from a local abattoir in ...

    African Journals Online (AJOL)

    Inoculation of pepsin digested muscle (mixed heart and diaphragm) from a slaughter pig into six Balb C mice resulted in the isolation of Toxoplasma gondii which proved to be pathogenic to mice. These infected mice were retarded in growth when compared to the two uninoculated control animals. Mouse No.3 and Mouse ...

  18. Presence of Toxoplasma gondii in Drinking Water from an Endemic Region in Southern Mexico.

    Science.gov (United States)

    Hernandez-Cortazar, Ivonne B; Acosta-Viana, Karla Y; Guzman-Marin, Eugenia; Ortega-Pacheco, Antonio; Segura-Correa, Jose C; Jimenez-Coello, Matilde

    2017-05-01

    Toxoplasmosis can be acquired through the ingestion of contaminated drinking water with oocysts of Toxoplasma gondii, highly resistant to the routinely disinfection processes; based on chlorination commonly used in the water supply industry. The aim of this study was to determine the presence of T. gondii DNA in samples of public drinking water from an endemic region of southern Mexico. In total 74 samples of water (5 L each) were collected from the three well fields (I, II, and III) and 71 independent wells, distributing public drinking water to the city of Merida Yucatan, after passing through the chlorination process. Water samples were filtered and concentrated by a sucrose solution, then DNA was extracted and evaluated through a nested-PCR (nPCR) specific for T. gondii. Positive samples were detected in 5.4% (4/74) of the water samples. This is the first report of the presence of T. gondii DNA in public drinking water from a large city in southern Mexico, where their consumption without any postpurification treatment could pose a risk for acquiring the infection in the urban population.

  19. History of the discovery of the life cycle of Toxoplasma gondii

    Science.gov (United States)

    It has been 100 years since the discovery of Toxoplasma gondii in 1908. Its full life cycle was not discovered until 1970 when it was found that it is a coccidian parasite of cats with all non feline warm blooded animals (including humans) as intermediate hosts. The discovery of the environmentally ...

  20. Transmission of Toxoplasma gondii - from land to sea: a personal perspective

    Science.gov (United States)

    It has been 100 years since the discovery of Toxoplasma gondii in 1908. Its full life cycle was not discovered until 1970 when it was found that it is a coccidian parasite of cats with all non-feline warm blooded animals (including humans) as intermediate hosts. The discovery of the environmentally ...

  1. por toxoplasma gondii en mujeres en edad fértil en albacete (2001-2007

    Directory of Open Access Journals (Sweden)

    Joaquín Bartolomé Álvarez

    2008-01-01

    Conclusiones: La prevalencia de la infección por T. gondii en mujeres nacidas en España fue la más baja de las publicadas hasta ahora. La incidencia de la infección en mujeres en edad fértil fue baja.

  2. PREVALENCE OF ANTIBODIES AGAINST TOXOPLASMA GONDII IN POLAR BEARS (URSUS MARITIMUS) FROM SVALBARD AND EAST GREENLAND

    Science.gov (United States)

    Serum samples from 419 polar bears (Ursus maritimus) from Svalbard and the Barents Sea (collected 1990 - 2000) and 108 polar bears from East Greenland (collected 1999 - 2004) were assayed for antibodies against Toxoplasma gondii using the modified agglutination test (MAT). Antibody prevalences were ...

  3. Detecção de Toxoplasma gondii no sêmen de ovinos naturalmente infectados

    Directory of Open Access Journals (Sweden)

    Érica P.B.X Moraes

    2010-11-01

    Full Text Available O objetivo deste trabalho foi estudar a eliminação de Toxoplasma gondii no sêmen de carneiros naturalmente infectados. Foram utilizados 65 reprodutores submetidos inicialmente à pesquisa de anticorpos anti-T. gondii por meio da técnica de imunofluorescência indireta (IFI. Os carneiros sorologicamente positivos foram submetidos à colheita de sêmen para detecção do DNA de T. gondii. Na sorologia observaram-se 6/65 (9,2% carneiros positivos, enquanto no PCR nested de sêmen 4/6 (66,6% carneiros foram positivos. Conclui-se que a detecção, por meio da técnica da PCR nested, da forma proliferativa de T. gondii no sêmen de carneiros naturalmente infectados, reforça a necessidade de se pesquisar sobre a possibilidade da transmissão horizontal do parasito via sêmen na espécie ovina.

  4. Antibodies to Toxoplasma gondii and Leishmania spp. in domestic cats from Luanda, Angola

    NARCIS (Netherlands)

    Lopes, Ana Patrícia; Oliveira, Ana Cristina; Granada, Sara; Rodrigues, Filipa T.; Papadopoulos, Elias; Schallig, Henk; Dubey, Jitender P.; Cardoso, Luís

    2017-01-01

    Toxoplasma gondii and Leishmania spp. are zoonotic protozoa of importance to animal and public health. The present study aimed to assess for the first time the seroprevalence of these zoonotic parasites in a domestic feline population living in Luanda, Angola. One hundred and two cats were sampled

  5. Detection of antibodies against Sarcocystis neurona, neospora spp., and Toxoplasma gondii in horses from Costa Rica

    Science.gov (United States)

    Serum samples from 315 horses from Costa Rica, Central America were examined for the presence of antibodies against Sarcocystis neurona, Neospora spp., and Toxoplasma gondii using the SnSAG2 ELISA, the NhSAG1 ELISA, and the modified agglutination test, respectively. Anti-S. neurona antibodies were f...

  6. Kennel dogs as sentinels of Leishmania infantum, Toxoplasma gondii and Neospora caninum in Majorca Island, Spain

    Science.gov (United States)

    Kennel dogs can serve as sentinels and/or reservoirs of diseases of veterinary and zoonotic interest because they have often roamed free and lived outdoors, being exposed to pathogens. We tested for evidence of infection with three protozoans, Leishmania infantum, Toxoplasma gondii and Neospora cani...

  7. First genetic characterization of Toxoplasma gondii in stray cats from Algeria.

    Science.gov (United States)

    Yekkour, Feriel; Aubert, Dominique; Mercier, Aurélien; Murat, Jean-Benjamin; Khames, Mammar; Nguewa, Paul; Ait-Oudhia, Khatima; Villena, Isabelle; Bouchene, Zahida

    2017-05-30

    Toxoplasmosis is a parasitic disease with worldwide distribution and a major public health problem. In Algeria, no data are currently available about genotypes of Toxoplasma gondii isolated from animals or humans. The present study assesses for the first time the seroprevalence of toxoplasmosis in stray cats, and provides molecular characterization of T. gondii strains circulating in this feline population in Algiers, the capital city of Algeria. Sera from 96 stray cats were tested for the presence of antibodies against T. gondii using the modified agglutination test. The seroprevalence was 50% (48/96) using 1:6 as the positivity cut-off. Different organs samples from stray cats, including heart samples, were tested for the presence of Toxoplasma DNA using real-time PCR. T. Gondii DNA was detected in 90.6% (87/96) of hearts. Of these parasitic DNAs, 22 were submitted to genotyping through the analysis of 15 microsatellite markers. The identified genotypes (12 of 22) mainly belonged to the type II lineage. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Isolation of viable Toxoplasma gondii, molecular characterization, and seroprevalence in elk (Cervus canadensis) in Pennsylvania, USA

    Science.gov (United States)

    Toxoplasmosis is a worldwide zoonosis. The ingestion of uncooked/undercooked meat and consumption of water contaminated with Toxoplasma gondii oocysts excreted by felids are the main modes of transmission of this parasite. Thousands of wild cervids are hunted or killed in traffic accidents yearly bu...

  9. High prevalance of Toxoplasma Gondii antibodies in domestic pigs in Oaxaca State, Mexico

    Science.gov (United States)

    Pigs are important in the epidemiology of toxoplasmosis in North America. Seroprevalence of Toxoplasma gondii infection in 525 domestic pigs (337 backyard raised, 188 farm raised) in Oaxaca state, Mexico was determined using the modified agglutination test (MAT, cut off 1:25). Antibodies to T. gondi...

  10. Genetic diversity of Toxoplasma gondii isolates from ruminants: A systematic review.

    Science.gov (United States)

    Sharif, Mehdi; Amouei, Afsaneh; Sarvi, Shahabeddin; Mizani, Azadeh; Aarabi, Mohsen; Hosseini, Seyed-Abdollah; Daryani, Ahmad

    2017-10-03

    Toxoplasma gondii is a protozoan capable of infecting all warm-blooded animals. This parasite has been classified into three major lineages. Our aim was to assess and compare the identified Types and genotypes in ruminants. From November 2014 to April 2015, four English language databases and four Persian databases that reported data on the T. gondii genotyping in ruminants were searched. Overall, typing results of the 250/307 T. gondii isolates in all animals showed that Type II was a predominant Type (81.4%). In addition, genotyping data from the 82/215 T. gondii isolates or strains indicated that atypical genotypes were predominant (38.13%). This systematic review has demonstrated a large degree of genetic diversity in some countries. However, in the new nomenclature of genotyping, there are atypical or exotic genotypes, such as Chinese 1, Types Br (I, II, III and IV), and Type 12. Further genotyping studies are required to corroborate the current results. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Seroprevalence of Toxoplasma gondii in captive antillean manatee (Trichechus manatus manatus) in Brazil

    Science.gov (United States)

    Antillean manatees (Trichechus manatus manatus) are aquatic mammals that inhabit marine waters from Central America to the northeastern region of Brazil and they are an endangered species. Infection with Toxoplasma gondii through intake of water or food contaminated with oocysts has been reported am...

  12. Occurrence of antibodies to Toxoplasma gondii in the scavenging black vultures (Coragyps atratus) from Brazil

    Science.gov (United States)

    This is the first report of Toxoplasma gondii infection in black vultures (Coragyps atratus) that are are obligate scavenging birds found throughout the American continent. Serum samples from 121 wild black vultures captured in urban areas of the city of São Paulo, SP, Brazil, were tested for the pr...

  13. Preliminary characterisation of Toxoplasma gondii isolates from Zimbabwe, with stage-specific monoclonal antibodies

    DEFF Research Database (Denmark)

    Hove, T.; Lind, Peter; Mukaratirwa, S.

    2005-01-01

    Cell-culture-derived clones of eight Toxoplasma gondii isolates from Zimbabwe were characterised in IFAT with a panel of five monoclonal antibodies (mAb). Each clone had been established from a single murine brain cyst. The antibodies were bradyzoite-specific (4.3), tachyzoite-specific (4.25, 5...

  14. Surface binding properties of aged and fresh (recently excreted) Toxoplasma gondii oocysts

    Science.gov (United States)

    The surface properties of aged (stored for 10 years) and fresh (recently excreted) oocysts of Toxoplasma gondii were investigated using monoclonal antibody (mAb) and lectin-binding assays. Fresh oocysts bound a wall-specific mAb labeled with fluorescein isothiocyanate while aged oocysts did not. In ...

  15. Seroprevalence of Toxoplasma gondii among turkeys on family farms in the state of Northeastern Brazil

    Science.gov (United States)

    The aim of the present study was to investigate the prevalence of antibodies against Toxoplasma gondii in turkeys and chickens on family farms in the semi-arid region of the state of Pernambuco, Brazil. In order to do so, 204 sera samples from turkeys were analyzed using the Modified Agglutination T...

  16. A study of virulence parameters for Toxoplasma gondii infections in mice

    DEFF Research Database (Denmark)

    Jensen, L.; Heegaard, Peter M. H.; Lind, Peter

    1998-01-01

    With the aim of establishing assessments of the virulence of Toxoplasma gondii isolates for mice, we investigated weight loss, serum levels of haptoglobin, and serum levels of tumor necrosis factor-alpha (TNF-alpha) as alternative parameters to mouse mortality. Groups of BALB/c mice were inoculated...

  17. Monoclonal antibodies to Toxoplasma gondii strain 119 identify recently isolated Danish strains as one group

    DEFF Research Database (Denmark)

    Jensen, L.; Petersen, E.; Henriksen, S.A.

    1998-01-01

    Four mAb raised against the Danish Toxoplasma gondii strain 119, were selected by screening hybridoma supernatants by indirect immunofluorescence against tachyzoites of the RH strain in order to obtain strain restricted markers. Strain restriction extended beyond discrimination of the 119 and RH...

  18. Early Infections of Toxoplasma gondii and the Later Development of Schizophrenia

    DEFF Research Database (Denmark)

    Mortensen, Preben Bo; Nørgaard-Pedersen, Bent; Waltoft, Berit Lindum

    2007-01-01

    Early exposure to several infectious agents has been associated with the later development of schizophrenia. Two recent studies assessed in utero or early postnatal exposure to Toxoplasma gondii. In one study of 63 individuals, who developed schizophrenia spectrum disorders, maternal sera obtained...

  19. Antibodies to Toxoplasma gondii and Leishmania spp. in domestic cats from Luanda, Angola

    Science.gov (United States)

    Toxoplasma gondii and Leishmania spp. are zoonotic agents of importance to public health, with domestic cats as potential reservoirs for both protozoal infections. The present study aimed at assessing for the first time the seroprevalence of these zoonotic parasites in a domestic feline population l...

  20. Toxoplasma gondii IgG antibodies in HIV/AIDS patients attending ...

    African Journals Online (AJOL)

    McRoy

    pneumonia;[2]. Cryptosporidium, Microsporidia, canthamoeba sp, Blastocystis hominis and Leishmania sp that cause severe enteritis, ulceration of the skin and menigoencephalitis.[3,4]. Various serological studies around the world reported that Toxoplasma gondii infection in HIV infected patients vary from geographical.