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Sample records for abstract toxoplasma gondii

  1. Toxoplasma gondii

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Toxoplasmosis, caused by Toxoplasma gondii, is one of the most common parasitic infections of humans and other warmblooded animals. It has been found worldwide, and nearly one third of humans have been exposed to the parasite. Congenital infection occurs when a woman becomes infected during pregnanc...

  2. Toxoplasma gondii and Schizophrenia

    PubMed Central

    Yolken, Robert H.

    2003-01-01

    Recent epidemiologic studies indicate that infectious agents may contribute to some cases of schizophrenia. In animals, infection with Toxoplasma gondii can alter behavior and neurotransmitter function. In humans, acute infection with T. gondii can produce psychotic symptoms similar to those displayed by persons with schizophrenia. Since 1953, a total of 19 studies of T. gondii antibodies in persons with schizophrenia and other severe psychiatric disorders and in controls have been reported; 18 reported a higher percentage of antibodies in the affected persons; in 11 studies the difference was statistically significant. Two other studies found that exposure to cats in childhood was a risk factor for the development of schizophrenia. Some medications used to treat schizophrenia inhibit the replication of T. gondii in cell culture. Establishing the role of T. gondii in the etiopathogenesis of schizophrenia might lead to new medications for its prevention and treatment. PMID:14725265

  3. Toxoplasma gondii proteomics

    PubMed Central

    Weiss, Louis M; Fiser, Andras; Angeletti, Ruth Hogue; Kim, Kami

    2009-01-01

    Toxoplasma gondii is a ubiquitous, Apicomplexan parasite that, in humans, can cause several clinical syndromes, including encephalitis, chorioretinitis and congenital infection. T. gondii was described a little over 100 years ago in the tissues of the gundi (Ctenodoactylus gundi). There are a large number of applicable experimental techniques available for this pathogen and it has become a model organism for the study of intracellular pathogens. With the completion of the genomes for a type I (GT-1), type II (ME49) and type III (VEG) strains, proteomic studies on this organism have been greatly facilitated. Several subcellular proteomic studies have been completed on this pathogen. These studies have helped elucidate specialized invasion organelles and their composition, as well as proteins associated with the cytoskeleton. Global proteomic studies are leading to improved strategies for genome annotation in this organism and an improved understanding of protein regulation in this pathogen. Web-based resources, such as EPIC-DB and ToxoDB, provide proteomic data and support for studies on T. gondii. This review will summarize the current status of proteomic research on T. gondii. PMID:19489701

  4. Salicylanilide inhibitors of Toxoplasma gondii

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Toxoplasma gondii (T. gondii) is an apicomplexan parasite that can cause eye disease, brain disease, and death, especially in congenitally infected and immunocompromised people. Novel medicines effective against both active and latent forms of the parasite are greatly needed. The current study foc...

  5. [Itraconazole action on Toxoplasma gondii].

    PubMed

    Jamra, L M; Amato Neto, V; Braz, L M; Camargo, M E

    1992-01-01

    With the purpose to increase our knowledge about the spectrum of therapeutic action of itraconazole, the activity of a new triazolic derivative against Toxoplasma gondii was studied in vivo and in vitro with the aid of an experimental infection model in mice. The trial also aimed at a possible improvement of the therapy of toxoplasmosis in regard to safety and dosing easiness. The present study has not shown significant activity of itraconazole against Toxoplasma gondii, differing from a previous observation that showed it's activity against Trypanosoma cruzi.

  6. Presumptive Toxoplasma gondii abortion in a sheep

    PubMed Central

    Weissmann, Judith

    2003-01-01

    A primiparous ewe aborted in mid-gestation. Toxoplasma gondii was suspected as the cause of abortion and a presumptive diagnosis of T. gondii abortion was based on histological lesions of the placenta. PMID:12715986

  7. Cathepsin proteases in Toxoplasma gondii

    PubMed Central

    Dou, Zhicheng; Carruthers, Vern B.

    2014-01-01

    Cysteine proteases are important for the growth and survival of apicomplexan parasites that infect humans. The apicomplexan Toxoplasma gondii expresses five members of the C1 family of cysteine proteases, including one cathepsin L-like (TgCPL), one cathepsin B-like (TgCPB), and three cathepsin C-like (TgCPC1, 2 and 3) proteases. Recent genetic, biochemical and structural studies reveal that cathepsins function in microneme and rhoptry protein maturation, host cell invasion, replication, and nutrient acquisition.. Here, we review the key features and roles of T. gondii cathepsins and discuss the therapeutic potential for specific inhibitor development. PMID:21660658

  8. Salicylanilide Inhibitors of Toxoplasma gondii

    PubMed Central

    Fomovska, Alina; Wood, Richard D.; Mui, Ernest; Dubey, Jitenter P.; Ferriera, Leandra R.; Hickman, Mark R.; Lee, Patricia J.; Leed, Susan E.; Auschwitz, Jennifer M.; Welsh, William J.; Sommerville, Caroline; Woods, Stuart; Roberts, Craig; McLeod, Rima

    2012-01-01

    Toxoplasma gondii(T. gondii) is an apicomplexan parasite that can cause eye disease, brain disease, and death, especially in congenitally infected and immune-compromised people. Novel medicines effective against both active and latent forms of the parasite are greatly needed. The current study focused on the discovery of such medicines by exploring a family of potential inhibitors whose anti-apicomplexan activity has not been previously reported. Initial screening efforts revealed that niclosamide, a drug approved for anthelmintic use, possessed promising activity in vitro against T. gondii. This observation inspired the evaluation of the activity of a series of salicylanilides and derivatives. Several inhibitors with activities in the nanomolar range with no appreciable in vitro toxicity to human cells were identified. An initial structure-activity relationship was explored. Four compounds were selected for evaluation in an in vivo model of infection, and two derivatives with potentially enhanced pharmacological parameters demonstrated the best activity profiles. PMID:22970937

  9. Salicylanilide inhibitors of Toxoplasma gondii.

    PubMed

    Fomovska, Alina; Wood, Richard D; Mui, Ernest; Dubey, Jitenter P; Ferreira, Leandra R; Hickman, Mark R; Lee, Patricia J; Leed, Susan E; Auschwitz, Jennifer M; Welsh, William J; Sommerville, Caroline; Woods, Stuart; Roberts, Craig; McLeod, Rima

    2012-10-11

    Toxoplasma gondii (T. gondii) is an apicomplexan parasite that can cause eye disease, brain disease, and death, especially in congenitally infected and immune-compromised people. Novel medicines effective against both active and latent forms of the parasite are greatly needed. The current study focused on the discovery of such medicines by exploring a family of potential inhibitors whose antiapicomplexan activity has not been previously reported. Initial screening efforts revealed that niclosamide, a drug approved for anthelmintic use, possessed promising activity in vitro against T. gondii. This observation inspired the evaluation of the activity of a series of salicylanilides and derivatives. Several inhibitors with activities in the nanomolar range with no appreciable in vitro toxicity to human cells were identified. An initial structure-activity relationship was explored. Four compounds were selected for evaluation in an in vivo model of infection, and two derivatives with potentially enhanced pharmacological parameters demonstrated the best activity profiles.

  10. Lytic Cycle of Toxoplasma gondii

    PubMed Central

    Black, Michael W.; Boothroyd, John C.

    2000-01-01

    Toxoplasma gondii is an obligate intracellular pathogen within the phylum Apicomplexa. This protozoan parasite is one of the most widespread, with a broad host range including many birds and mammals and a geographic range that is nearly worldwide. While infection of healthy adults is usually relatively mild, serious disease can result in utero or when the host is immunocompromised. This sophisticated eukaryote has many specialized features that make it well suited to its intracellular lifestyle. In this review, we describe the current knowledge of how the asexual tachyzoite stage of Toxoplasma attaches to, invades, replicates in, and exits the host cell. Since this process is closely analogous to the way in which viruses reproduce, we refer to it as the Toxoplasma “lytic cycle.” PMID:10974128

  11. Detection Method of TOXOPLASMA GONDII Tachyzoites

    NASA Astrophysics Data System (ADS)

    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).

  12. Seroprevalence of Toxoplasma gondii in pigs, sheep, goats, and cattle from Grenada and Carriacou, West Indies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Technical Abstract: Prevalence of Toxoplasma gondii infection in pregnant women in Grenada is considered high. Little is known of the epidemiology of T. gondii infection in Caribbean Islands. Serum samples of 750 food animals in Grenada and Carriacou were tested for antibodies to T. gondii using th...

  13. Seroprevalence of Toxoplasma gondii in Western Romania.

    PubMed

    Olariu, Tudor Rares; Petrescu, Cristina; Darabus, Gheorghe; Lighezan, Rodica; Mazilu, Octavian

    2015-08-01

    Toxoplasma gondii is an obligate intracellular parasite that most commonly causes asymptomatic infection in immunocompetent hosts, but can have devastating consequences in congenitally infected infants and immunocompromised patients. We evaluated the seroprevalence of T. gondii in the general population in Western Romania. Sera from 304 individuals were analysed with the Pastorex Toxo test, which allows the simultaneous detection of T. gondii IgG and/or IgM antibodies. T. gondii antibodies were demonstrated in 197 individuals (64.8%) and the prevalence increased with age: 35.0% in those < 20 years versus 76.8% in those ≥ 70 years (p < 0.001). There was a higher prevalence of T. gondii antibodies in rural areas (76.9%) than in urban regions (55.3%) (p < 0.001). Our results suggest a high prevalence of T. gondii antibodies in Western Romania.

  14. Purine metabolism in Toxoplasma gondii

    SciTech Connect

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

    1989-06-25

    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.

  15. Autophagy activated by Toxoplasma gondii infection in turn facilitates Toxoplasma gondii proliferation.

    PubMed

    Gao, Dongmei; Zhang, Jing; Zhao, Jun; Wen, He; Pan, Jiwen; Zhang, Shouzhu; Fang, Yong; Li, Xiuyi; Cai, Yu; Wang, Xuelong; Wang, Shiping

    2014-06-01

    Autophagy was found to play an antimicrobial or antiparasitic role in the activation of host cells to defend against intracellular pathogens, at the same time, pathogens could compete with host cell and take advantage of autophagy to provide access for its proliferation, but there are few articles for studying the outcome of this competition between host cell and pathogens. Therefore, the aim of our study was to investigate the relationship between autophagy activated by Toxoplasma gondii (T. gondii) and proliferation of T. gondii affected by autophagy in vitro. Firstly, human embryonic fibroblasts (HEF) cells were infected with T. gondii for different times. The monodansylcadaverine (MDC) staining, acridine orange (AO) staining, punctuate GFP-LC3 distribution, and transmission electron microscopy (TEM) assays were conducted, and the results were consistent in showing that gondii infection could induce autophagy. Secondly, HEF cells were infected with T. gondii and treated with autophagy inhibitor bafilomycin A1 or inducer lithium chloride for different times. Giemsa staining was conducted, and the results exhibited that T. gondii infection-induced autophagy could in turn promote T. gondii proliferation. Simultaneously, the results of Giemsa staining also revealed that autophagy inhibitor could reduce the number of each cell infected with T. gondii and inhibit T. gondii proliferation. In contrast, autophagy inducer could increase the number of each cell infected with T. gondii and encourage T. gondii proliferation. Therefore, our study suggests that T. gondii infection could activate autophagy, and this autophagy could in turn facilitate T. gondii proliferation in HEF cells for limiting nutrients.

  16. Mechanics of the Toxoplasma gondii oocyst wall

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  17. RESEARCH NOTE: AUTOFLUORESCENCE OF TOXOPLASMA GONDII OOCYSTS

    EPA Science Inventory

    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 ...

  18. Toxoplasma gondii infection in humans in China

    PubMed Central

    2011-01-01

    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. PMID:21864327

  19. Mechanisms and pathways of Toxoplasma gondii transepithelial migration

    PubMed Central

    Jones, Emily J.; Carding, Simon R.

    2017-01-01

    ABSTRACT Toxoplasma gondii is a ubiquitous parasite and a prevalent food-borne parasitic pathogen. Infection of the host occurs principally through oral consumption of contaminated food and water with the gastrointestinal tract being the primary route for entry into the host. To promote infection, T. gondii has evolved highly specialized strategies for rapid traversal of the single cell thick intestinal epithelial barrier. Parasite transmigration via the paracellular pathway between adjacent cells enables parasite dissemination to secondary sites of infection where chronic infection of muscle and brain tissue is established. It has recently been proposed that parasite interactions with the integral tight junction (TJ) protein occludin influences parasite transmigration of the intestinal epithelium. We review here the emerging mechanisms of T. gondii transmigration of the small intestinal epithelium alongside the developing role played in modulating the wider TJ-associated proteome to rewire host cell regulatory systems for the benefit of the parasite.

  20. Toxoplasma gondii Chitinase Induces Macrophage Activation

    PubMed Central

    Almeida, Fausto; Sardinha-Silva, Aline; da Silva, Thiago Aparecido; Pessoni, André Moreira; Pinzan, Camila Figueiredo; Alegre-Maller, Ana Claudia Paiva; Cecílio, Nerry Tatiana; Moretti, Nilmar Silvio; Damásio, André Ricardo Lima; Pedersoli, Wellington Ramos; Mineo, José Roberto; Silva, Roberto Nascimento; Roque-Barreira, Maria Cristina

    2015-01-01

    Toxoplasma gondii is an obligate intracellular protozoan parasite found worldwide that is able to chronically infect almost all vertebrate species, especially birds and mammalians. Chitinases are essential to various biological processes, and some pathogens rely on chitinases for successful parasitization. Here, we purified and characterized a chitinase from T. gondii. The enzyme, provisionally named Tg_chitinase, has a molecular mass of 13.7 kDa and exhibits a Km of 0.34 mM and a Vmax of 2.64. The optimal environmental conditions for enzymatic function were at pH 4.0 and 50°C. Tg_chitinase was immunolocalized in the cytoplasm of highly virulent T. gondii RH strain tachyzoites, mainly at the apical extremity. Tg_chitinase induced macrophage activation as manifested by the production of high levels of pro-inflammatory cytokines, a pathogenic hallmark of T. gondii infection. In conclusion, to our knowledge, we describe for the first time a chitinase of T. gondii tachyzoites and provide evidence that this enzyme might influence the pathogenesis of T. gondii infection. PMID:26659253

  1. Molecular detection of Toxoplasma gondii in snakes.

    PubMed

    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.

  2. THE TOXOPLASMA GONDII OOCYST FROM CAT FECES

    PubMed Central

    Dubey, J. P.; Miller, Nancy L.; Frenkel, J. K.

    1970-01-01

    cysts. The classification of T. gondii is discussed in relation to that of other isosporan coccidia of cats and dogs. The term "Toxoplasma oocyst" is introduced and Toxoplasma is classified in the family Toxoplasmidae of the suborder Eimeriina. The species Isospora bigemina is restricted to dogs, and I. cati to cats. I. felis and so-called I. rivolta from cats were noninfectious to dogs, and did not confer immunity to subsequent infection with I. canis and I. rivolta from dogs. PMID:4927658

  3. The Toxoplasma gondii oocyst from cat feces.

    PubMed

    Dubey, J P; Miller, N L; Frenkel, J K

    1970-10-01

    classification of T. gondii is discussed in relation to that of other isosporan coccidia of cats and dogs. The term "Toxoplasma oocyst" is introduced and Toxoplasma is classified in the family Toxoplasmidae of the suborder Eimeriina. The species Isospora bigemina is restricted to dogs, and I. cati to cats. I. felis and so-called I. rivolta from cats were noninfectious to dogs, and did not confer immunity to subsequent infection with I. canis and I. rivolta from dogs.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  5. Seroprevalence of Toxoplasma gondii infection in marine mammals in Mexico

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Toxoplasma gondii infection in marine mammals is important because they are considered as a sentinel for contamination of seas with T. gondii oocysts, and toxoplasmosis causes mortality in these animals, particularly sea otters. Seroprevalence of T. gondii infection was determined in 75 captive mari...

  6. TOXOPLASMA GONDII IN MESOCARNIVORES IN CANADA SEROPREVALENCE OF TOXOPLASMA GONDII IN MESOCARNIVORE OF THE CANADIAN PRAIRIES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The protozoon Toxoplasma gondii has a worldwide distribution and affects many species of warm-blooded animals. In the Canadian prairies, mesocarnivores such as striped skunks (Mephitis mephitis) and raccoons (Procyon lotor) have experienced an increase in density and distribution and are in close c...

  7. Toxoplasma gondii: from animals to humans

    PubMed Central

    Tenter, Astrid M.; Heckeroth, Anja R.; Weiss, Louis M.

    2011-01-01

    Toxoplasmosis is one of the more common parasitic zoonoses world-wide. Its causative agent, Toxoplasma gondii, is a facultatively heteroxenous, polyxenous protozoon that has developed several potential routes of transmission within and between different host species. If first contracted during pregnancy, T. gondii may be transmitted vertically by tachyzoites that are passed to the foetus via the placenta. Horizontal transmission of T. gondii may involve three life-cycle stages, i.e. ingesting infectious oocysts from the environment or ingesting tissue cysts or tachyzoites which are contained in meat or primary offal (viscera) of many different animals. Transmission may also occur via tachyzoites contained in blood products, tissue transplants, or unpasteurised milk. However, it is not known which of these routes is more important epidemiologically. In the past, the consumption of raw or undercooked meat, in particular of pigs and sheep, has been regarded as a major route of transmission to humans. However, recent studies showed that the prevalence of T. gondii in meat-producing animals decreased considerably over the past 20 years in areas with intensive farm management. For example, in several countries of the European Union prevalences of T. gondii in fattening pigs are now <1%. Considering these data it is unlikely that pork is still a major source of infection for humans in these countries. However, it is likely that the major routes of transmission are different in human populations with differences in culture and eating habits. In the Americas, recent outbreaks of acute toxoplasmosis in humans have been associated with oocyst contamination of the environment. Therefore, future epidemiological studies on T. gondii infections should consider the role of oocysts as potential sources of infection for humans, and methods to monitor these are currently being developed. This review presents recent epidemiological data on T. gondii, hypotheses on the major routes of

  8. Prevalence of antibodies to Toxoplasma gondii in South Korean wild boar (Sus scrofa coreanus).

    PubMed

    Jeong, Wooseog; Yoon, Hachung; Kim, Yong Kwan; Moon, Oun-Kyong; Kim, Do-Soon; An, Dong-Jun

    2014-10-01

    Abstract Toxoplasma gondii is an obligate intracellular protozoan parasite and a commonly encountered pathogen in humans and animals. The wild boar (Sus scrofa coreanus) is considered a good indicator when monitoring environmental contamination by T. gondii. We surveyed the prevalence of antibodies against T. gondii in wild boars from South Korea. Blood samples were collected from 426 wild boars captured in eight provinces of South Korea during the hunting seasons in 2008-12. Antibodies against T. gondii were detected using an indirect enzyme-linked immunosorbent assay in samples from 152 of boars, indicating an overall antibody prevalence of 36% (95% confidence interval=31-40%).

  9. Development of forward genetics in Toxoplasma gondii

    PubMed Central

    Sibley, L. David

    2009-01-01

    The development of forward genetics as a functional system in Toxoplasma gondii spanned more than three decades from the mid-1970s until now. The initial demonstration of experimental genetics relied on chemically-induced drug resistant mutants that were crossed by co-infecting cats, collecting oocysts, sporulating and hatching progeny in vitro. To capitalize on this, genetic markers were employed to develop linkage maps by tracking inheritance through experimental crosses. In all, three generations of genetic maps were developed to define the chromosomes, estimate recombination rates, and provide a system for linkage analysis. Ultimately this genetic map would become the foundation for the assembly of the T. gondii genome, which was derived from whole genome shotgun sequencing, into a chromosome-centric view. Finally, application of forward genetics to multigenic biological traits showed the potential to map and identify specific genes that control complex phenotypes including virulence. PMID:19254720

  10. Mechanisms of Toxoplasma gondii persistence and latency

    PubMed Central

    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

  11. Characterization of aspartyl aminopeptidase from Toxoplasma gondii

    PubMed Central

    Zheng, Jun; Cheng, Ziying; Jia, Honglin; Zheng, Yonghui

    2016-01-01

    Aminopeptidases have emerged as new promising drug targets for the development of novel anti-parasitic drugs. An aspartyl aminopeptidase-like gene has been identified in the Toxoplasma gondii genome (TgAAP), although its function remains unknown. In this study, we characterized TgAAP and performed functional analysis of the gene product. Firstly, we expressed a functional recombinant TgAAP (rTgAAP) protein in Escherichia coli, and found that it required metal ions for activity and showed a substrate preference for N-terminal acidic amino acids Glu and Asp. Then, we evaluated the function and drug target potential of TgAAP using the CRISPR/Cas9 knockout system. Western blotting demonstrated the deletion of TgAAP in the knockout strain. Indirect immunofluorescence analysis showed that TgAAP was localized in the cytoplasm of the wild-type parasite, but was not expressed in the knockout strain. Phenotype analysis revealed that TgAAP knockout inhibited the attachment/invasion, replication, and substrate-specific activity in T. gondii. Finally, the activity of drug CID 23724194, previously described as targeting Plasmodium and malarial parasite AAP, was tested against rTgAAP and the parasite. Overall, TgAAP knockout affected the growth of T. gondii but did not completely abolish parasite replication and growth. Therefore, TgAAP may comprise a useful adjunct drug target of T. gondii. PMID:27678060

  12. Toxoplasma gondii Ingests and Digests Host Cytosolic Proteins

    PubMed Central

    Dou, Zhicheng; McGovern, Olivia L.; Di Cristina, Manlio

    2014-01-01

    ABSTRACT The protozoan parasite Toxoplasma gondii resides within a nonfusogenic vacuole during intracellular replication. Although the limiting membrane of this vacuole provides a protective barrier to acidification and degradation by lysosomal hydrolases, it also physically segregates the parasite from the host cytosol. Accordingly, it has been suggested that T. gondii acquires material from the host via membrane channels or transporters. The ability of the parasite to internalize macromolecules via endocytosis during intracellular replication has not been tested. Here, we show that Toxoplasma ingests host cytosolic proteins and digests them using cathepsin L and other proteases within its endolysosomal system. Ingestion was reduced in mutant parasites lacking an intravacuolar network of tubular membranes, implicating this apparatus as a possible conduit for trafficking to the parasite. Genetic ablation of proteins involved in the pathway is associated with diminished parasite replication and virulence attenuation. We show that both virulent type I and avirulent type II strain parasites ingest and digest host-derived protein, indicating that the pathway is not restricted to highly virulent strains. The findings provide the first definitive evidence that T. gondii internalizes proteins from the host during intracellular residence and suggest that protein digestion within the endolysosomal system of the parasite contributes to toxoplasmosis. PMID:25028423

  13. Mechanics of the Toxoplasma gondii oocyst wall

    PubMed Central

    Dumètre, Aurélien; Dubey, Jitender P.; Ferguson, David J. P.; Bongrand, Pierre; Azas, Nadine; Puech, Pierre-Henri

    2013-01-01

    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 harsh environmental conditions until their ingestion by the host. None of the common disinfectants are effective in killing the parasite because the oocyst wall acts as a primary barrier to physical and chemical attacks. Here, we address the structure and chemistry of the wall of the T. gondii oocyst by combining wall surface treatments, fluorescence imaging, EM, and measurements of its mechanical characteristics by using atomic force microscopy. Elasticity and indentation measurements indicated that the oocyst wall resembles common plastic materials, based on the Young moduli, E, evaluated by atomic force microscopy. Our study demonstrates that the inner layer is as robust as the bilayered wall itself. Besides wall mechanics, our results suggest important differences regarding the nonspecific adhesive properties of each layer. All together, these findings suggest a key biological role for the oocyst wall mechanics in maintaining the integrity of the T. gondii oocysts in the environment or after exposure to disinfectants, and therefore their potential infectivity to humans and animals. PMID:23798399

  14. On the determination of Toxoplasma gondii virulence in mice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  15. Seroprevalence of Toxoplasma gondii antibodies in wild carnivores from Spain

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Serum samples from 282 wild carnivores from different regions of Spain were tested for antibodies to Toxoplasma gondii by the modified agglutination test using a cut-off value of 1:25. Antibodies to T. gondii were found in 22 of 27 (81.5%) of Iberian lynx (Lynx pardinus), three of six European wildc...

  16. Experimental toxoplasma gondii infection in striped skunk (Mephitis mephitis)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 given T. gondii. Skunks were bled be...

  17. Identification of a sporozoite-specific antigen from Toxoplasma gondii

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Toxoplasma gondii is an apicomplexan parasite that causes the disease toxoplasmosis. Toxoplasmosis results in the loss of life, sight, cognitive and motor function, and hearing in congenitally infected individuals. While the sources of T. gondii infection have been established, the factors influen...

  18. Toxoplasma gondii: history and diagnostic test development.

    PubMed

    Wyrosdick, Heidi M; Schaefer, John J

    2015-12-01

    Toxoplasma gondii is a protozoa that causes toxoplasmosis in people and other animals. It is considered one of the most common parasitic infections in the world due to its impressive range of hosts, widespread environmental contamination and the diverse means by which animals can be infected. Despite its ubiquity and numerous ongoing research efforts into both its basic biology and clinical management, many aspects of diagnosis and management of this disease are poorly understood. The range of diagnostic options that is available for veterinary diagnostic investigators are notably more limited than those available to medical diagnosticians, making accurate interpretation of each test result critical. The current review joins other reviews on the parasite with a particular emphasis on the history and continued development of diagnostic tests that are useful for veterinary diagnostic investigations. An understanding of the strengths and shortcomings of current diagnostic techniques will assist veterinary and public health officials in formulating effective treatment and control strategies in diverse animal populations.

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

    PubMed

    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%) (P<0.05). The present study is the first report that analyzed the prevalence of T. gondii infection in sheep in Belgium and confirms the high prevalence of Toxoplasma-specific IgG antibodies in the sheep population.

  20. Recent Advances in Toxoplasma gondii Immunotherapeutics

    PubMed Central

    Othman, Rofina Yasmin

    2014-01-01

    Toxoplasmosis is an opportunistic infection caused by the protozoan parasite Toxoplasma gondii. T. gondii is widespread globally and causes severe diseases in individuals with impaired immune defences as well as congenitally infected infants. The high prevalence rate in some parts of the world such as South America and Africa, coupled with the current drug treatments that trigger hypersensitivity reactions, makes the development of immunotherapeutics intervention a highly important research priority. Immunotherapeutics strategies could either be a vaccine which would confer a pre-emptive immunity to infection, or passive immunization in cases of disease recrudescence or recurrent clinical diseases. As the severity of clinical manifestations is often greater in developing nations, the development of well-tolerated and safe immunotherapeutics becomes not only a scientific pursuit, but a humanitarian enterprise. In the last few years, much progress has been made in vaccine research with new antigens, novel adjuvants, and innovative vaccine delivery such as nanoparticles and antigen encapsulations. A literature search over the past 5 years showed that most experimental studies were focused on DNA vaccination at 52%, followed by protein vaccination which formed 36% of the studies, live attenuated vaccinations at 9%, and heterologous vaccination at 3%; while there were few on passive immunization. Recent progress in studies on vaccination, passive immunization, as well as insights gained from these immunotherapeutics is highlighted in this review. PMID:25548409

  1. Toxoplasma gondii decreases the reproductive fitness in mice.

    PubMed

    Dvorakova-Hortova, Katerina; Sidlova, Adela; Ded, Lukas; Hladovcova, Denisa; Vieweg, Markus; Weidner, Wolfgang; Steger, Klaus; Stopka, Pavel; Paradowska-Dogan, Agnieszka

    2014-01-01

    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 contribute to an increase

  2. Potential contamination of drinking water with Toxoplasma gondii oocysts.

    PubMed Central

    Aramini, J. J.; Stephen, C.; Dubey, J. P.; Engelstoft, C.; Schwantje, H.; Ribble, C. S.

    1999-01-01

    The world's first documented toxoplasmosis outbreak associated with a municipal water supply was recognized in 1995 in Victoria, British Columbia, Canada. It was hypothesized that domestic cat (Felis catus) or cougar (Felis concolor) faeces contaminated a surface water reservoir with Toxoplasma gondii oocysts. An extensive investigation of the Victoria watershed 1 year following the outbreak documented the presence of an endemic T. gondii cycle involving the animals inhabiting the area. Cats and cougars were observed throughout the watershed. Serological evidence of T. gondii infection was demonstrated among domestic cats living in the Victoria area. Cougars were found to shed T. gondii oocysts. Serological evidence of T. gondii infection in deer mice living in the riparian environments of the watershed suggested that T. gondii oocysts were being shed near the water edge. Contamination of Victoria's water supply with T. gondii oocysts potentially occurred during the study period and future waterborne toxoplasmosis outbreaks in this and other communities are possible. PMID:10355797

  3. Biological and molecular characterizations of Toxoplasma gondii strains

    USGS Publications Warehouse

    Cole, R.A.; Lindsay, D.S.; Howe, D.K.; Roderick, Constance L.; Dubey, J.P.; Thomas, N.J.; Baeten, L.A.

    2000-01-01

    Toxoplasma gondii was isolated from brain or heart tissue from 15 southern sea otters (Enhydra lutris nereis) in cell cultures. These strains were used to infect mice that developed antibodies to T. gondii as detected in the modified direct agglutination test and had T. gondii tissue cysts in their brains at necropsy. Mouse brains containing tissue cysts from 4 of the strains were fed to 4 cats. Two of the cats excreted T. gondii oocysts in their feces that were infectious for mice. Molecular analyses of 13 strains indicated that they were all type II strains, but that they were genetically distinct from one another.

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

    NASA Astrophysics Data System (ADS)

    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. Virus-Like Nanoparticle Vaccine Confers Protection against Toxoplasma gondii

    PubMed Central

    Lee, Dong Hun; Lee, Su Hwa; Kim, Ah Ra; Quan, Fu Shi

    2016-01-01

    The inner membrane complex (IMC) of Toxoplasma gondii as a peripheral membrane system has unique and critical roles in parasite replication, motility and invasion. Disruption of IMC sub-compartment protein produces a severe defect in T. gondii endodyogeny, the form of internal cell budding. In this study, we generated T. gondii virus-like particle particles (VLPs) containing proteins derived from IMC, and investigated their efficacy as a vaccine in mice. VLP vaccination induced Toxoplasma gondii-specific total IgG, IgG1 and IgG2a antibody responses in the sera and IgA antibody responses in the feces. Upon challenge infection with a lethal dose of T. gondii (ME49), all vaccinated mice survived, whereas all naïve control mice died. Vaccinated mice showed significantly reduced cyst load and cyst size in the brain. VLP vaccination also induced IgA and IgG antibody responses in feces and intestines, and antibody-secreting plasma cells, mixed Th1/Th2 cytokines and CD4+/CD8+ T cells from spleen. Taken together, these results indicate that non-replicating VLPs containing inner membrane complex of T. gondii represent a promising strategy for the development of a safe and effective vaccine to control the spread of Toxoplasma gondii infection. PMID:27548677

  6. Kinematic analysis of Toxoplasma gondii motility.

    PubMed

    Frixione, E; Mondragón, R; Meza, I

    1996-01-01

    Toxoplasma gondii tachyzoites execute a complex and little understood combination of rapid movements to reach and penetrate human or other animals cells. In the present study, computer-assisted simulation was used to quantitatively analyze the motility of these parasites in three-dimensional space with spatial and temporal resolutions in the micrometer and subsecond ranges. A digital model based on electron-micrographs of a serially sectioned tachyzoite was animated according to a videomicrographed sequence of a characteristic repetitive movement. Keyframe animation defined over 150 frames by a total of 36 kinematic parameters for specific motions, of both the whole model and particular domains, resulted in a real-time life-like simulation of the videorecorded tachyzoite movement. The kinematic values indicate that a full revolution of the model is composed of three half-turns accomplished in nearly 5 s with two phases: a relatively slow 180 degrees tilting with regard to the substratum plane, followed by fast (over 200 degrees/s) spinning almost simultaneous with pivoting around the posterior end, each clockwise and for about 180 degrees. Maximal flexing of the body, as well as bowing and retraction of its anterior end, occur at midway during the tilting phase. An estimated 70 degrees. clockwise torsion of the body seems to precede the spinning-pivoting phase. The results suggest the operation of two basic forces in the motility of T. gondii tachyzoites: (1) a clockwise torque that causes torsion, spinning, and pivoting; and (2) a longitudinal pull that contracts, bends and tilts the parasite. We discuss the possibility that both of these forces might result from the action of an actin-myosin system enveloping the twisted framework of microtubules characteristic of these organisms.

  7. Deciphering the Draft Genome of Toxoplasma gondii RH Strain

    PubMed Central

    Gudimella, Ranganath; Zhang, GuiPing; Ching, Xiao-Teng; Razali, Rozaimi; Aziz, Farhanah; Anwar, Arif; Fong, Mun-Yik

    2016-01-01

    Toxoplasmosis is a widespread parasitic infection by Toxoplasma gondii, a parasite with at least three distinct clonal lineages. This article reports the whole genome sequencing and de novo assembly of T. gondii RH (type I representative strain), as well as genome-wide comparison across major T. gondii lineages. Genomic DNA was extracted from tachyzoites of T. gondii RH strain and its identity was verified by PCR and LAMP. Subsequently, whole genome sequencing was performed, followed by sequence filtering, genome assembly, gene annotation assignments, clustering of gene orthologs and phylogenetic tree construction. Genome comparison was done with the already archived genomes of T. gondii. From this study, the genome size of T. gondii RH strain was found to be 69.35Mb, with a mean GC content of 52%. The genome shares high similarity to the archived genomes of T. gondii GT1, ME49 and VEG strains. Nevertheless, 111 genes were found to be unique to T. gondii RH strain. Importantly, unique genes annotated to functions that are potentially critical for T. gondii virulence were found, which may explain the unique phenotypes of this particular strain. This report complements the genomic archive of T. gondii. Data obtained from this study contribute to better understanding of T. gondii and serve as a reference for future studies on this parasite. PMID:27355363

  8. Seroprevalence of Toxoplasma gondii in goats in Hunan province, China

    PubMed Central

    Li, Fen; Wang, Shi-Ping; Wang, Chang-Jian; He, Shi-Cheng; Wu, Xiang; Liu, Guo-Hua

    2016-01-01

    Toxoplasma gondii infections are prevalent in animals and humans worldwide. In the present investigation, the seroprevalence of T. gondii in goats was investigated in Hunan province, subtropical China between March 2014 and December 2015. A total of 1,028 serum samples collected from 14 administrative regions of Hunan province were evaluated by the indirect hemagglutination test (IHAT) for the detection of specific antibodies. Antibodies to T. gondii were detected in 124 serum samples (12%). The T. gondii seroprevalence ranged from 1.7% to 19% among different regions in subtropical China, and the differences were statistically significant (p < 0.01). The results of the present survey indicated that T. gondii infection is prevalent in goats in Hunan, which poses a potential risk for human infection with T. gondii in this province. PMID:27762212

  9. Dynamics of the Toxoplasma gondii inner membrane complex

    PubMed Central

    Ouologuem, Dinkorma T.; Roos, David S.

    2014-01-01

    ABSTRACT Unlike most cells, protozoa in the phylum Apicomplexa divide by a distinctive process in which multiple daughters are assembled within the mother (schizogony or endodyogeny), using scaffolding known as the inner membrane complex (IMC). The IMC underlies the plasma membrane during interphase, but new daughters develop in the cytoplasm, as cytoskeletal filaments associate with flattened membrane cisternae (alveolae), which elongate rapidly to encapsulate subcellular organelles. Newly assembled daughters acquire their plasma membrane as they emerge from the mother, leaving behind vestiges of the maternal cell. Although the maternal plasma membrane remains intact throughout this process, the maternal IMC disappears – is it degraded, or recycled to form the daughter IMC? Exploiting fluorescently tagged IMC markers, we have used live-cell imaging, fluorescence recovery after photobleaching (FRAP) and mEos2 photoactivation to monitor the dynamics of IMC biogenesis and turnover during the replication of Toxoplasma gondii tachyzoites. These studies reveal that the formation of the T. gondii IMC involves two distinct steps – de novo assembly during daughter IMC elongation within the mother cell, followed by recycling of maternal IMC membranes after the emergence of daughters from the mother cell. PMID:24928899

  10. Toxoplasma gondii antibodies in exotic wild felids from Brazilian zoos.

    PubMed

    Silva, J C; Ogassawara, S; Marvulo, M F; Ferreira-Neto, J S; Dubey, J P

    2001-09-01

    Serum samples from 37 captive exotic felids in 12 zoos from six Brazilian states were assayed for antibodies to Toxoplasma gondii by the modified agglutination test using formalin-fixed whole tachyzoites. Titers greater than or equal to 1:20 were considered positive. Antibodies to T. gondii were found in 24 of 37 (64.9%) felids, including one European lynx (Lynx lynx), two jungle cats (Felis chaus), two servals (Leptailurus serval), two tigers (Panthera tigris), three leopards (Panthera pardus), and 14 of 27 lions (Panthera leo). This is the first serologic analysis for T. gondii infection in exotic wild felids from Brazilian zoos.

  11. Surface properties of Toxoplasma gondii oocysts and surrogate microspheres.

    PubMed

    Shapiro, Karen; Largier, John; Mazet, Jonna A K; Bernt, William; Ell, John R; Melli, Ann C; Conrad, Patricia A

    2009-02-01

    The physical properties that govern the waterborne transmission of Toxoplasma gondii oocysts from land to sea were evaluated and compared to the properties of carboxylated microspheres, which could serve as surrogates for T. gondii oocysts in transport and water treatment studies. The electrophoretic mobilities of T. gondii oocysts, lightly carboxylated Dragon Green microspheres, and heavily carboxylated Glacial Blue microspheres were determined in ultrapure water, artificial freshwater with and without dissolved organic carbon, artificial estuarine water, and artificial seawater. The surface wettabilities of oocysts and microspheres were determined using a water contact angle approach. Toxoplasma gondii oocysts and microspheres were negatively charged in freshwater solutions, but their charges were neutralized in estuarine water and seawater. Oocysts, Glacial Blue microspheres, and unwashed Dragon Green microspheres had low contact angles, indicating that they were hydrophilic; however, once washed, Dragon Green microspheres became markedly hydrophobic. The hydrophilic nature and negative charge of T. gondii oocysts in freshwater could facilitate widespread contamination of waterways. The loss of charge observed in saline waters may lead to flocculation and subsequent accumulation of T. gondii oocysts in locations where freshwater and marine water mix, indicating a high risk of exposure for humans and wildlife in estuarine habitats with this zoonotic pathogen. While microspheres did not have surface properties identical to those of T. gondii, similar properties shared between each microsphere type and oocysts suggest that their joint application in transport and fate studies could provide a range of transport potentials in which oocysts are likely to behave.

  12. Mechanical transmission of Toxoplasma gondii oocysts by dogs.

    PubMed

    Lindsay, D S; Dubey, J P; Butler, J M; Blagburn, B L

    1997-12-15

    Two experiments were conducted to determine if dogs could mechanically transmit Toxoplasma gondii after ingesting cat feces or by rolling in cat feces containing oocysts. In the first experiment, two dogs were fed sporulated T. gondii oocysts; viable sporulated oocysts were present in dog feces for up to 2 days postinoculation (PI). Both dogs seroconverted to T. gondii but did not develop clinical signs of toxoplasmosis. In the second experiment, nonsporulated oocysts were placed on dog skin and fur, and fur clippings were bioassayed for T. gondii in mice. Oocysts did not sporulate on dog fur. The results of this study support the hypothesis that dogs may be involved in the mechanical transmission of T. gondii to humans.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  14. Population genetics, diversity and spread of virulence in Toxoplasma gondii

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Globally, an estimated third of the human population harbors infection with Toxoplasma gondii, a single-celled eukaryotic parasite belonging to the phylum Apicomplexa (Dubey, 2010). Most infected persons are unaware of, and evidently unharmed by, the parasite cysts established in their muscles and/...

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

    EPA Science Inventory

    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...

  16. The neurotropic parasite Toxoplasma gondii increases dopamine metabolism

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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. ISOLATION OF TOXOPLASMA GONDII FROM ANIMALS IN DURANGO, MEXICO

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Little is known concerning the epidemiology of Toxoplasma gondii infection in people and animals in rural Mexico. Serum samples and tissues from 150 dogs, 150 cats, 65 opossums (Didelphis virginianus), 249 rats (Rattus spp.), 127 mice (Mus musculus), and 69 squirrels (Spermophilus variegatus) from t...

  18. New description of Toxoplasma gondii genotypes from French Polynesia.

    PubMed

    Yera, Hélène; Ajzenberg, Daniel; Lesle, Florence; Eyrolle-Guignot, Dominique; Besnard, Marianne; Baud, Alain; Georges, Amandine; Dupouy-Camet, Jean; Dardé, Marie Laure

    2014-06-01

    We report here the first isolation and genotyping of two human Toxoplasma gondii strains from French Polynesia. The parasites had new and atypical genotypes, and were responsible for asymptomatic congenital toxoplasmosis. Both genotypes were divergent from the common strains isolated in Europe, North America, South America, Africa and China.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  20. Genetic diversity among sea otter isolates of Toxoplasma gondii

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sea otters (Enhydra lutris) have been reported to become infected with Toxoplasma gondii and at times succumb to clinical disease. The mode of marine contamination has been the subject of recent papers. Because of their susceptibility these animals can serve as a sentinel for contamination of marine...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  2. Toxoplasma gondii infection in Blanford's fox (Vulpes cana)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fatal toxoplasmosis was diagnosed in a Blanford's fox (Vulpes cana) from the United Arab Emirates. Toxoplasma gondii-like tachyzoites were found associated with necrosis in intestine, spleen, liver, kidneys, lungs, skeletal muscle, brain and heart. Protozoal tachyzoites reacted positively with T. go...

  3. Detection of toxoplasma gondii with a DNA molecular beacon probe

    NASA Astrophysics Data System (ADS)

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

    2008-12-01

    Toxoplasma gondii is a microscopic parasite that may infect humans, so there is an increasing concern on the early detection of latent Toxoplasma gondii infection in recent years. We currently report a rapid and sensitive method for Toxoplasma gondii based on molecular beacon (MB) probe. The probe based on fluorescence resonance energy transfer (FRET) with a stem-loop DNA oligonucleotide was labeled with CdTe/ZnS quantum dots (energy donor) at 5' end and BHQ-2 (energy acceptor) at 3' end, respectively. The probe was synthesized in PBS buffer at pH 8.2, room temperature for 24 h. Then target DNA was injected under the condition of 37°C, hybridization for 2 h, in Tris-HCl buffer. The data from fluorescence spectrum (FS) showed that ca 65% of emitted fluorescence was quenched, and about 50% recovery of fluorescence intensity was observed after adding target DNA, which indicated that the target DNA was successfully detected by MB probe. The detecting limitation was determined as ca 5 nM. Moreover, specificity of the probe was investigated by adding target DNA with one-base-pair mismatch, the low fluorescence recovery indicated the high specificity. The results showed that the current sensing probe will be a useful and convenient tool in Toxoplasma gondii early detection.

  4. ISOLATION OF TOXOPLASMA GONDII FROM BOTTLENOSE DOLPHINS (TURSIOPS TRUNCATUS)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Toxoplasma gondii infection in marine mammals is intriguing and indicative of contamination of the ocean environment and coastal waters with oocysts. In previous serological surveys > 90% of bottlenose dolphins (Tursiops truncatus) from the coasts of Florida, South Carolina, and California had antib...

  5. SEROPREVALENCE OF TOXOPLASMA GONDII ANTIBODIES IN CATS FROM PENNSLYVANIA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The prevalence of antibodies to Toxoplasma gondii was determined in sera from 122 domestic cats from Bensalem, Pennsylvania. Using a modified agglutination test, antibodies to this parasite were found in 25 (20.4%) of the 122 cats with titers of 1:25 in 1, 1:50 in 4, 1:100 in 6, 1:200 in 3, 1:400...

  6. Acute disseminated encephalomyelitis associated with acute Toxoplasma gondii Infection.

    PubMed

    Aksoy, Ayse; Tanir, Gonul; Ozkan, Mehpare; Oguz, Melek; Yıldız, Yasemin Tasci

    2013-03-01

    Acute disseminated encephalomyelitis is an acute demyelinating disorder of the central nervous system, which principally affects the brain and spinal cord. It usually follows a benign infection or vaccination in children. Although a number of infectious agents have been implicated in acute disseminated encephalomyelitis, Toxoplasma gondii infection has not been described previously in children. Acquired T. gondii infection presents with lymphadenopathy and fever and usually spontaneously resolves in immunocompetent patients. We describe a previously healthy 10-year-old boy with acute disseminated encephalomyelitis associated with acute acquired Toxoplasma gondii infection, the symptoms of which initially began with nuchal stiffness, difficulty in walking, and urinary and stool incontinence; he later had development of motor and sensory impairment in both lower extremities and classical magnetic resonance imaging lesions suggestive of the disease. The patient recovered completely after the specific therapy for acquired T. gondii infection and pulse prednisolone. Although acute acquired Toxoplasma gondii infection has not been reported previously in association with acute disseminated encephalomyelitis, clinicians should keep in mind this uncommon cause of a common disease when evaluating a patient with acute disseminated encephalomyelitis.

  7. Synthesis and Evaluation of Oryzalin Analogs against Toxoplasma gondii

    PubMed Central

    Endeshaw, Molla M.; Li, Catherine; de Leon, Jessica; Yao, Ni; Latibeaudiere, Kirk; Premalatha, Kokku; Morrissette, Naomi; Werbovetz, Karl A.

    2010-01-01

    The synthesis and evaluation of twenty dinitroanilines and related compounds against the obligate intracellular parasite Toxoplasma gondii is reported. Using in vitro cultures of parasites in human fibroblasts, we determined that most of these compounds selectively disrupted Toxoplasma microtubules, and several displayed sub-micromolar potency against the parasite. The most potent compound was N1,N1-dipropyl-2,6-dinitro-4-(trifuoromethyl)-1,3-benzenediamine (18b), which displayed an IC50 value of 36 nM against intracellular T. gondii. Based on these data and another recent report (Ma, C.; Tran, J.; Gu, F.; Ochoa, R.; Li, C.; Sept, D.; Werbovetz, K.; Morrissette, N. Antimicrob. Agents Chemother. 2010, 54, 1453), an antimitotic structure-activity relationship for dinitroanilines vs. Toxoplasma is presented. PMID:20675138

  8. Tachyzoite-induced life cycle of Toxoplasma gondii in cats.

    PubMed

    Dubey, J P

    2002-08-01

    The tachyzoite-induced cycle of Toxoplasma gondii was studied in 46 cats. Tachyzoites of the M-7741 or Me-49 strain of T. gondii were administered orally to cats by pouring into the mouth or by stomach tube, or by intraintestinal inoculation. Ten weaned cats that had been inoculated with tachyzoites directly in the intestine were killed 1, 3, 6, 9, 12, 15, 18, or 25 days later, and their tissues were studied histologically and bioassayed in mice. Toxoplasma gondii was demonstrable in the blood of 8 cats and in other tissues of all these 10. Four out of five 1- to 8-day-old cats fed tachyzoites by stomach tube became infected with T. gondii, and 1 became ill because of toxoplasmosis. All 19 weaned cats fed tachyzoites (poured into the mouth) became infected, and 6 died of acute toxoplasmosis 9-15 days after being fed T. gondii. Six out of 12 weaned cats fed tachyzoites by stomach tube became infected but were asymptomatic. Overall, 12 out of 26 cats observed for 19 days or more shed oocysts with a prepatent period (pp) of 19 days or more, with the sole exception of 1 cat that shed oocysts with a pp of 5 days. Enteroepithelial stages of T. gondii were not found in any cat before oocysts were shed. Cats shed up to 360 million oocysts in a day, and oocysts were shed for 4-6 days.

  9. The effect of Toxoplasma cell fractions and mycobacterial immunostimulants against virulent Toxoplasma gondii in mice.

    PubMed

    Masihi, K N; Brehmer, W; Werner, H

    1979-01-01

    Toxoplasma gondii tachyzoites were disrupted in a Ribi cell fractionator and separated into cell walls and protoplasm by differential centrifugation. These products were used alone or combined with a mycobacterial glycolipid (P3) and injected either as oil-in-water emulsions or incorporated in Freund's incomplete adjuvant. Mice were vaccinated by intravenous or intradermal routes and challenged intraperitoneally with a highly virulent strain of Toxoplasma gondii. A local granuloma formation was induced after i.d. inoculation of Toxoplasma vaccines containing P3 as this glycolipid enabled an adherence of the antigens on the mineral oil droplets. The adjuvant effect of P3 on antibody formation was also observed. Most of the fractions showed a low, but statistically significant prolongation of survival time. Vaccination by the i.v. route with homologous or heterologous antigens, including Trypanosoma cruzi, were not significantly effective, with the exception of a high dose of Toxoplasma protoplasm associated with P3.

  10. Prevalence of Toxoplasma gondii in Dogs in Zhanjiang, Southern China.

    PubMed

    Jiang, Hai-Hai; Li, Ming-Wei; Xu, Min-Jun; Cong, Wei; Zhu, Xing-Quan

    2015-08-01

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

  11. Toxoplasma gondii coinfection with diseases and parasites in wild rabbits in Scotland

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In wild rabbits (Oryctolagus cuniculus) on an estate in Perthshire, central Scotland, the seroprevalence of Toxoplasma gondii was 18/548 (3.3 %). The wild rabbit could be a T. gondii reservoir and it has potential value as a sentinel of T. gondii in environmental substrates. T. gondii was associated...

  12. Fatal Toxoplasma gondii infection in the giant panda

    PubMed Central

    Ma, Hongyu; Wang, Zedong; Wang, Chengdong; Li, Caiwu; Wei, Feng; Liu, Quan

    2015-01-01

    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. PMID:26514595

  13. Monitoring of dynamin during the Toxoplasma gondii cell cycle.

    PubMed

    Caldas, Lucio Ayres; Soares, Leandro Lemgruber; Henrique Seabra, Sergio; Attias, Marcia; de Souza, Wanderley

    2016-12-01

    The obligate intracellular protozoan parasite Toxoplasma gondii actively invades virtually all warm-blooded nucleated cells. This process results in a non-fusogenic vacuole, inside which the parasites replicate continuously until egress signaling is triggered. In this work, we investigated the role of the large GTPase dynamin in the interaction of T. gondii with the host cell by using laser and electron microscopy during three key stages: invasion, development and egress. The detection of dynamin during invasion indicates the occurrence of endocytosis, while T. gondii egress appeared to be independent of dynamin participation. However, the presence of dynamin during T. gondii development suggests that this molecule plays undescribed roles in the tachyzoite's cell cycle.

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

    PubMed

    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.

  15. Fatal Toxoplasma gondii infection in the giant panda.

    PubMed

    Ma, Hongyu; Wang, Zedong; Wang, Chengdong; Li, Caiwu; Wei, Feng; Liu, Quan

    2015-01-01

    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.

  16. Serological Evidence of Toxoplasma gondii Infection in Five Species of Bats in China

    PubMed Central

    Yuan, Zi-Guo; Luo, Sheng-Jun; Dubey, Jitender P.; Zhou, Dong-Hui; Zhu, Yan-Ping; He, Yong; He, Xian-Hui

    2013-01-01

    Abstract Toxoplasma gondii is an obligate intracellular protozoan parasite that 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 coronavirus (SARS-CoV). However, little is known of T. gondii infection in bats. The objective of the present study was to determine the seroprevalence of T. gondii infection in bats in China. A total of 217 serum samples from 5 species of bats were collected between April, 2010, and August, 2011, from 4 provinces in China. Antibodies to T. gondii were determined using the modified agglutination test (MAT, 1:25 or higher). Antibodies to T. gondii were found in 26.5% (18/68) Megaderma lyra, 13.6% (12/88) Rousettus leschenaulti, 13.6% (3/22) Cynopterus sphinx, 20% (4/20) Vespertilio superaus, and 15.8% (3/19) Pipistrellus javanicus. Antibody titers ranged from 1:25 to 1:400, with titers of 1:200 detected in 4 of the 5 bat species. The present study suggests the likely occurrence of T. gondii infection in bats in China, and these bats are new putative hosts for T. gondii, which may pose a threat to human health. PMID:23473226

  17. Targeting tumors with nonreplicating Toxoplasma gondii uracil auxotroph vaccines

    PubMed Central

    Fox, Barbara A.; Sanders, Kiah L.; Chen, Shan; Bzik, David J.

    2013-01-01

    Toxoplasma gondii is an intracellular parasite that has evolved to actively control its invaded host cells. Toxoplasma triggers then actively regulates host innate IL-12 and interferon-γ responses that elicit T cell control of infection. A live, nonreplicating avirulent uracil auxotroph vaccine strain (cps) of Toxoplasma triggers novel innate immune responses that stimulate amplified CD8+ T cell responses and life-long immunity in vaccinated mice. Here, we review recent reports showing that intratumoral treatment with cps activated immune-mediated regression of established solid tumors in mice. We speculate that a better understanding of host-parasite interaction at the molecular level and applying improved genetic models based on Δku80 Toxoplasma strains will stimulate development of highly effective immunotherapeutic cancer vaccine strategies using engineered uracil auxotrophs. PMID:23928100

  18. Is Toxoplasma gondii a Trigger of Bipolar Disorder?

    PubMed Central

    Del Grande, Claudia; Galli, Luca; Schiavi, Elisa; Dell’Osso, Liliana; Bruschi, Fabrizio

    2017-01-01

    Toxoplasma gondii, a ubiquitous intracellular parasite, has a strong tropism for the brain tissue, where it forms intracellular cysts within the neurons and glial cells, establishing a chronic infection. Although latent toxoplasmosis is generally assumed to be asymptomatic in immunocompetent individuals, it is now clear that it can induce behavioral manipulations in mice and infected humans. Moreover, a strong relation has emerged in recent years between toxoplasmosis and psychiatric disorders. The link between T. gondii and schizophrenia has been the most widely documented; however, a significant association with bipolar disorder (BD) and suicidal/aggressive behaviors has also been detected. T. gondii may play a role in the etiopathogenesis of psychiatric disorders affecting neurotransmitters, especially dopamine, that are implicated in the emergence of psychosis and behavioral Toxoplasma-induced abnormalities, and inducing brain inflammation by the direct stimulation of inflammatory cytokines in the central nervous system. Besides this, there is increasing evidence for a prominent role of immune dysregulation in psychosis and BD. The aim of this review is to describe recent evidence suggesting a link between Toxoplasma gondii and BD, focusing on the interaction between immune responses and this infectious agent in the etiopathogenesis of psychiatric symptoms. PMID:28075410

  19. Concentrating Toxoplasma gondii and Cyclospora cayetanensis from Surface Water and Drinking Water by Continuous Separation Channel Centrifugation

    EPA Science Inventory

    Aims: To evaluate the effectiveness of continuous separation channel centrifugation for concentrating Toxoplasma gondii and Cyclospora cayetanensis from drinking water and environmental waters. Methods and Results: Ready-to-seed vials with known quantities of Toxoplasma gondii a...

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

    PubMed

    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.

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

    NASA Astrophysics Data System (ADS)

    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.

  2. Genetic diversity of Toxoplasma gondii isolates from Ethiopian feral cats.

    PubMed

    Dubey, J P; Choudhary, S; Tilahun, G; Tiao, N; Gebreyes, W A; Zou, X; Su, C

    2013-09-01

    Recent studies indicate greater genetic variability among isolates of Toxoplasma gondii worldwide than previously thought. However, there is no information on genetic diversity of T. gondii from any host in Ethiopia. In the present study, genotyping was performed on viable T. gondii isolates by bioassays in mice from tissues and feces of 27 cats from Ethiopia. Viable T. gondii was isolated from hearts of 26 cats, feces alone of 1 cat, and feces and tissues of 6 cats; in total there were 33 isolates. Genotyping was performed on DNA from cell-cultured derived T. gondii tachyzoites and by using 10 PCR-restriction fragment length polymorphism markers (SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico). Four genotypes were recognized, including ToxoDB #1 (Type II clonal, nine isolates), ToxoDB #2 (Type III, five isolates), Toxo DB #3 (Type II variant, ten isolates), and ToxoDB #20 (nine isolates). Of interest is the isolation of different genotypes from tissues and feces of two cats, suggesting re-infection or mixed strain T. gondii infection. These findings are of epidemiological significance with respect to shedding of oocysts by cats. This is the first report of genotyping of T. gondii from any host in Ethiopia.

  3. High Toxoplasma gondii Seropositivity among Brain Tumor Patients in Korea

    PubMed Central

    Jung, Bong-Kwang; Song, Hyemi; Kim, Min-Jae; Cho, Jaeeun; Shin, Eun-Hee; Chai, Jong-Yil

    2016-01-01

    Toxoplasma gondii is an intracellular protozoan that can modulate the environment of the infected host. An unfavorable environment modulated by T. gondii in the brain includes tumor microenvironment. Literature has suggested that T. gondii infection is associated with development of brain tumors. However, in Korea, epidemiological data regarding this correlation have been scarce. In this study, in order to investigate the relationship between T. gondii infection and brain tumor development, we investigated the seroprevalence of T. gondii among 93 confirmed brain tumor patients (various histological types, including meningioma and astrocytoma) in Korea using ELISA. The results revealed that T. gondii seropositivity among brain tumor patients (18.3%) was significantly (P<0.05) higher compared with that of healthy controls (8.6%). The seropositivity of brain tumor patients showed a significant age-tendency, i.e., higher in younger age group, compared with age-matched healthy controls (P<0.05). In conclusion, this study supports the close relationship between T. gondii infection and incidence of brain tumors. PMID:27180580

  4. Seroprevalence of Toxoplasma gondii in mesocarnivores of the Canadian prairies.

    PubMed

    Hwang, Y T; Pitt, J A; Quirk, T W; Dubey, J P

    2007-12-01

    The protozoon Toxoplasma gondii has a worldwide distribution and affects many species of warm-blooded animals. In the Canadian prairies, mesocarnivores such as striped skunks (Mephitis mephitis) and raccoons (Procyon lotor) have experienced an increase in density and distribution, and they are in close contact with human dwellings. However, there has been no systematic study on the seroprevalence of T. gondii in these mesocarnivore populations. The objectives of the current project were to determine the serum antibody prevalence of T. gondii in Canadian prairie mesocarnivores and to study the relationship between antibody prevalence and species, sex, age, location, and year of collection. Antibodies to T. gondii were found in 5 of 24 (20.8%) skunks from Saskatchewan trapped in 1999 and 5 of 40 (12.5%) in 2000. Seroprevalences for T. gondii in raccoons and skunks trapped in Manitoba were 2 of 10 (20%) raccoons trapped in 2002, 7 of 44 (15.9%) trapped in 2003, and 16 of 37 (43.2%) trapped in 2004; and in 13 of 99 (13.1%) skunks trapped in 2003, 29 of 131 (22.1%) trapped in 2004, 53 of 165 (32.1%) trapped in 2005, and 30 of 51 (58.8%) trapped in 2006. Age, location, and year, but not the host species, were important variables in the determining the seroprevalence of T. gondii in skunks and raccoons. Results confirm that T. gondii is endemic in the skunk and raccoon populations in the Canadian prairies.

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

    PubMed

    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.

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

    PubMed Central

    Njunda, Anna L.; Assob, Jules C.N.; Nsagha, Dickson S.; Kamga, Henri L.; Nde, Peter F.; Yugah, Vuchas C.

    2011-01-01

    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 of 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. PMID:28299065

  7. Experimental Toxoplasma gondii infection in grey seals (Halichoerus grypus).

    PubMed

    Gajadhar, A A; Measures, L; Forbes, L B; Kapel, C; Dubey, J P

    2004-04-01

    Laboratory-reared animals were used to assess the susceptibility of seals (Halichoerus grypus) to Toxoplasma gondii infection. Four seals were each orally inoculated with 100 or 10,000 oocysts of T. gondii (VEG strain), and another 4 seals served as negative controls. Occasionally, mild behavioral changes were observed in all inoculated seals but not in control animals. A modified agglutination test revealed the presence of antibodies to T. gondii in sera collected from inoculated seals and mice inoculated as controls. No evidence of the parasite was found on an extensive histological examination of seal tissues, and immunohistochemical staining of tissue sections from inoculated seals revealed a single tissue cyst in only 1 seal. Control mice inoculated with 10 oocysts from the same inoculum given to seals became serologically and histologically positive for T. gondii. Cats that were fed brain 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.

  8. Diagnosis of toxoplasmosis and typing of Toxoplasma gondii.

    PubMed

    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.

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

    PubMed

    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.

  10. Toxoplasma gondii in wild and domestic animals from New Caledonia.

    PubMed

    Roqueplo, C; Halos, L; Cabre, O; Davoust, B

    2011-11-01

    Samples (serum or meat juice) collected from 205 animals in New Caledonia in April 2009 were tested for antibodies against Toxoplasma gondii by ELISA using the multi-species ID Screen® Toxoplasmosis Indirect kit (IDVET, Montpellier). Antibodies to T. gondii were detected in 2% (1/49) of the pigs, in 3.3% (1/30) of the cattle, in 13.8% (4/29) of Rusa deers, in 16% (4/25) of the horses, in 32.8% (21/64) of the dogs, and in 50% (4/8) of cats. Statistically, no significant difference was observed between T. gondii seroprevalence and age or sex. No survey on the prevalence of T. gondii in animals has ever been conducted in New Caledonia and this is the first serological evidence of T. gondii in Rusa deer (Cervus timorensis russa). These results indicate an important circulation of T. gondii exists in the animal populations of New Caledonia. In view of humans being exposed, it is advisable to insist on sanitary education and on respect for good hygienic and food practice.

  11. Shear forces enhance Toxoplasma gondii tachyzoite motility on vascular endothelium.

    PubMed

    Harker, Katherine S; Jivan, Elizabeth; McWhorter, Frances Y; Liu, Wendy F; Lodoen, Melissa B

    2014-04-01

    Toxoplasma gondii is a highly successful parasite that infects approximately one-third of the human population and can cause fatal disease in immunocompromised individuals. Systemic parasite dissemination to organs such as the brain and eye is critical to pathogenesis. T. gondii can disseminate via the circulation, and both intracellular and extracellular modes of transport have been proposed. However, the processes by which extracellular tachyzoites adhere to and migrate across vascular endothelium under the conditions of rapidly flowing blood remain unknown. We used microfluidics and time-lapse fluorescence microscopy to examine the interactions between extracellular T. gondii and primary human endothelial cells under conditions of physiologic shear stress. Remarkably, tachyzoites adhered to and glided on human vascular endothelium under shear stress conditions. Compared to static conditions, shear stress enhanced T. gondii helical gliding, resulting in a significantly greater displacement, and increased the percentage of tachyzoites that invaded or migrated across the endothelium. The intensity of the shear forces (from 0.5 to 10 dynes/cm(2)) influenced both initial and sustained adhesion to endothelium. By examining tachyzoites deficient in the T. gondii adhesion protein MIC2, we found that MIC2 contributed to initial adhesion but was not required for adhesion strengthening. These data suggest that under fluidic conditions, T. gondii adhesion to endothelium may be mediated by a multistep cascade of interactions that is governed by unique combinations of adhesion molecules. This work provides novel information about tachyzoite interactions with vascular endothelium and contributes to our understanding of T. gondii dissemination in the infected host. IMPORTANCE Toxoplasma gondii is a global parasite pathogen that can cause fatal disease in immunocompromised individuals. An unresolved question is how the parasites circulate in the body to tissues to cause disease

  12. Isolation of encysted Toxoplasma gondii from musculature of moose and pronghorn in Montana.

    PubMed

    Dubey, J P

    1981-01-01

    Pieces of skeletal muscle from 43 mule deer, 34 elk, 4 white-tailed deer, 21 pronghorn, 7 moose, and 2 bison were examined for Toxoplasma infection, by the acid-pepsin digestion technique. Toxoplasma gondii was isolated from 1 moose and 1 pronghorn. The isolated strains of T gondii were of low virulence to mice.

  13. Seroprevalence of Toxoplasma gondii infection in dairy goats in Michoacan, Mexico

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Seroprevalence of Toxoplasma gondii infection in goats in Michoacán, Mexico is largely unknown. Antibodies to T. gondii were determined in 341 dairy goats in Michoacán, Mexico using the modified agglutination test. Goats were raised in 9 farms in 6 municipalities. Overall, antibodies to Toxoplasma w...

  14. Seroprevalence and correlates of Toxoplasma gondii infection in domestic pigs in Veracruz State, Mexico

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Toxoplasma gondii infection in pigs has epidemiological concern for its contributing role in human infections. We determined seroprevalence of Toxoplasma gondii infection in 402 domestic pigs raised in backyards in Veracruz State, Mexico using the modified agglutination test (MAT, cut off 1:25); 182...

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

    PubMed Central

    Boucher, Lauren E.; Bosch, Jürgen

    2014-01-01

    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 P22121, 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. PMID:25195889

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

    PubMed

    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.

  17. Toxoplasma gondii in an African crested porcupine (Hystrix cristata).

    PubMed

    Harrison, Tara M; Moorman, Jamee Black; Bolin, Steven R; Grosjean, Nicole L; Lim, Ailam; Fitzgerald, Scott D

    2007-03-01

    An adult female crested porcupine (Hystrix cristata) was evaluated for acute onset of neurologic signs including head tilt, circling, and ataxia. She was found dead in her holding area 2 days after initially exhibiting clinical signs. Necropsy was unremarkable. Histopathology of brain tissue revealed the presence of protozoal cysts associated with inflammation as the underlying cause of clinical signs and death. Immunohistochemical staining of brain tissue for Toxoplasma gondii was strongly positive. PCR on fresh brain confirmed T. gondii as the causative organism. An adult male in the same enclosure has demonstrated similar neurologic signs over the past 3 years and has failed to respond to various medical treatments. Clinical disease associated with T. gondii has not been previously reported in this porcupine species or any other Old World porcupines, although there are several reports of clinical toxoplasmosis involving New World porcupine species.

  18. Genetic characterization of Toxoplasma gondii in wildlife from Alabama, USA.

    PubMed

    Yu, Li; Shen, Jilong; Su, Chunlei; Sundermann, Christine A

    2013-03-01

    The genetic diversity of Toxoplasma gondii circulating in wildlife is of interest to understand the transmission of this parasite in the environment. In the present study, we genetically characterized five T. gondii isolates from different wild animals including two isolates from a bobcat (Lynx rufus), one from a red-shouldered hawk (Buteo lineatus), one from a white-tailed deer (Odocoileus virginianus), and one from a bald eagle (Haliaeetus leucocephalus). Genotyping of these samples using 11 PCR-restriction fragment length polymorphism markers (SAG1, 5'- and 3'-SAG2, alt.SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico) revealed two types, including type I (ToxoDB#10) and type 12 (ToxoDB#5). This is the first report of genetic characterization of T. gondii strains in wildlife from Alabama and from a red-shouldered hawk.

  19. Identification of new Palmitoylated Proteins in Toxoplasma gondii

    PubMed Central

    Caballero, Marina C.; Alonso, Andrés M.; Deng, Bin; Attias, Marcia; de Souza, Wanderley; Corvi, María M.

    2016-01-01

    Protein palmitoylation has been shown to be an important post-translational modification in eukaryotic cells. This modification alters the localization and/or the function of the targeted protein. In the recent years protein palmitoylation has risen in importance in apicomplexan parasites as well. In Toxoplasma gondii, some proteins have been reported to be modified by palmitate. With the development of new techniques that allow the isolation of palmitoylated proteins, this significant post-translational modification has begun to be studied in more detail in T. gondii. Here we describe the palmitoylome of the tachyzoite stage of T. gondii using a combination of the acyl-biotin exchange chemistry method and mass spectrometry analysis. We identified 401 proteins found in multiple cellular compartments, with a wide range of functions that vary from metabolic processes, gliding and host-cell invasion to even regulation of transcription and translation. Besides, we found that more rhoptry proteins than the ones already described for Toxoplasma are palmitoylated, suggesting an important role for this modification in the invasion mechanism of the host-cell. This study documents that protein palmitoylation is a common modification in T. gondii that could have an impact on different cellular processes. PMID:26825284

  20. Pneumocystis carinii, Toxoplasma gondii, Cytomegalovirus and the Compromised Host

    PubMed Central

    Ryning, Frank W.; Mills, John

    1979-01-01

    Pneumocystis carinii and Toxoplasma gondii are the two major parasitic protozoan pathogens in the immunocompromised host. Both organisms cause latent infection in humans and many animals. Cats are the definitive hosts for toxoplasmosis; the animal vector for pneumocystis (if any) has not been defined. Toxoplasma is an obligate intracellular parasite, whereas the available evidence suggests that Pneumocystis carinii exists primarily extracellularly. In compromised hosts, pneumocystis infection usually involves only lungs, whereas toxoplasma causes a generalized infection with encephalitis being the principal clinical manifestation. Both types of infection are treated with combinations of folate antagonists (trimethoprim or pyrimethamine with sulfonamide). Both parasites are associated with cytomegalovirus infection in immunosuppressed hosts, an association which may be due to symbiosis between parasites, or to an additive immunosuppressive effect of dual infection on the hosts. ImagesFigure 1.Figure 3.Figure 4.Figure 7.Figure 8.Figure 9. PMID:217182

  1. The Dialogue of Metastasis-Uncovering Juxtacrine Genetic Cascades with a Toxoplasma Gondii Enzyme

    DTIC Science & Technology

    2008-08-01

    1-0574 TITLE: The Dialogue of Metastasis-Uncovering Juxtacrine Genetic Cascades with a Toxoplasma Gondii Enzyme PRINCIPAL...a Toxoplasma Gondii Enzyme 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Richard A. Steinman, M.D., Ph.D. 5d. PROJECT NUMBER...intact tumors. The proposed investigations overcome these limitations through use of a toxoplasma ghondii enzyme. It should then be feasible for

  2. ISOLATION OF TOXOPLASMA GONDII FROM THE KEEL-BILLED TOUCAN (RAMPHASTOS SULFURATUS) FROM COSTA RICA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pectoral muscles from a captive keel-billed toucan (Ramphastos sulfuratus) from the Costa Rican were fed to a Toxoplasma gondii-free cat and the cat shed oocysts. Laboratory mice fed these oocysts developed antibodies to T. gondii in their sera and T. gondii tissue cysts in their brains. The DNA ext...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  5. TOXOPLASMA GONDII AND NEOSPORA CANINUM ANTIBODIES IN DOGS FROM GRENADA, WEST INDIES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Toxoplasma gondii and Neospora caninum are structurally similar parasites with many common hosts. The prevalence of antibodies to T. gondii and N. caninum was determined in sera from dogs in Grenada, West Indies. Using a modified agglutination test, antibodies to T. gondii were found in 52 (48.5%) o...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  8. First isolate of Toxoplasma gondii from arctic fox (Vulpes lagopus) from Svalbard

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cats are considered essential for the maintenance of Toxoplasma gondii in nature. However, T. gondii infection has been reported in arctic fox (Vulpes lagopus) from the Svalbard high arctic archipelago where felids are virtually absent. To identify the potential source of T. gondii, we attempted to ...

  9. TOXOPLASMA GONDII ISOLATES FROM FREE-RANGE CHICKENS FORM THE NORTHEAST REGION OF BRAZIL

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The prevalence of Toxoplasma gondii in free-ranging chickens is a good indicator of the prevalence of T. gondii oocysts in the soil because chickens feed from the ground. The prevalence of T. gondii in 152 free-range chickens (Gallus domesticus) from 22 municipalities in 7 northeastern states (Perna...

  10. Factors affecting seroprevalence of Toxoplasma gondii in the endangered Iberian lynx (Lynx pardinus)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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. In the present stud...

  11. Isolation and genetic characterization of Toxoplasma gondii from mute swan (Cygnus olor) from the USA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Little is known of the genetic diversity of Toxoplasma gondii circulating in wildlife. In the present study, antibodies to T. gondii were determined in serum samples from 632 mute swans (Cygnus olor) collected from different areas of the USA. Sera were tested by T. gondii modified agglutination te...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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. Proteomic Profiling of Mouse Liver following Acute Toxoplasma gondii Infection.

    PubMed

    He, Jun-Jun; Ma, Jun; Elsheikha, Hany M; Song, Hui-Qun; Zhou, Dong-Hui; Zhu, Xing-Quan

    2016-01-01

    Toxoplasma gondii remains a global public health problem. However, its pathophysiology is still not-completely understood particularly the impact of infection on host liver metabolism. We performed iTRAQ-based proteomic analysis to evaluate early liver protein responses in BALB/c mice following infection with T. gondii PYS strain (genotype ToxoDB#9) infection. Our data revealed modification of protein expression in key metabolic pathways, as indicated by the upregulation of immune response and downregulation of mitochondrial respiratory chain, and the metabolism of fatty acids, lipids and xenobiotics. T. gondii seems to hijack host PPAR signaling pathway to downregulate the metabolism of fatty acids, lipids and energy in the liver. The metabolism of over 400 substances was affected by the downregulation of genes involved in xenobiotic metabolism. The top 10 transcription factors used by upregulated genes were Stat2, Stat1, Irf2, Irf1, Sp2, Egr1, Stat3, Klf4, Elf1 and Gabpa, while the top 10 transcription factors of downregulated genes were Hnf4A, Ewsr1, Fli1, Hnf4g, Nr2f1, Pparg, Rxra, Hnf1A, Foxa1 and Foxo1. These findings indicate global reprogramming of the metabolism of the mouse liver after acute T. gondii infection. Functional characterization of the altered proteins may enhance understanding of the host responses to T. gondii infection and lead to the identification of new therapeutic targets.

  14. Proteomic Profiling of Mouse Liver following Acute Toxoplasma gondii Infection

    PubMed Central

    He, Jun-Jun; Ma, Jun; Elsheikha, Hany M.; Song, Hui-Qun; Zhou, Dong-Hui; Zhu, Xing-Quan

    2016-01-01

    Toxoplasma gondii remains a global public health problem. However, its pathophysiology is still not-completely understood particularly the impact of infection on host liver metabolism. We performed iTRAQ-based proteomic analysis to evaluate early liver protein responses in BALB/c mice following infection with T. gondii PYS strain (genotype ToxoDB#9) infection. Our data revealed modification of protein expression in key metabolic pathways, as indicated by the upregulation of immune response and downregulation of mitochondrial respiratory chain, and the metabolism of fatty acids, lipids and xenobiotics. T. gondii seems to hijack host PPAR signaling pathway to downregulate the metabolism of fatty acids, lipids and energy in the liver. The metabolism of over 400 substances was affected by the downregulation of genes involved in xenobiotic metabolism. The top 10 transcription factors used by upregulated genes were Stat2, Stat1, Irf2, Irf1, Sp2, Egr1, Stat3, Klf4, Elf1 and Gabpa, while the top 10 transcription factors of downregulated genes were Hnf4A, Ewsr1, Fli1, Hnf4g, Nr2f1, Pparg, Rxra, Hnf1A, Foxa1 and Foxo1. These findings indicate global reprogramming of the metabolism of the mouse liver after acute T. gondii infection. Functional characterization of the altered proteins may enhance understanding of the host responses to T. gondii infection and lead to the identification of new therapeutic targets. PMID:27003162

  15. Seroprevalence of Toxoplasma gondii antibodies in wild birds in Taiwan.

    PubMed

    Chen, Ju-Chi; Tsai, Yu-Jen; Wu, Ying-Ling

    2015-10-01

    Toxoplasma gondii is a zoonotic protozoon which is well known for infecting humans and wild animals. In the present study, antibodies to T. gondii were evaluated in 394 wild birds, belonging to 37 species, from 15 different administrative regions in Taiwan. Using modified agglutination test (MAT), the overall seroprevalence of infection was 23.35% (CI 95% = 19.17%-27.53%). Antibodies were detected in birds of prey (25.73%, CI 95% = 19.76%-31.70%), birds living in freshwater or marine systems (34.29%, CI 95% = 18.56%-50.01%) and ground-feeding birds (18.12%, CI 95% = 11.94%-24.31%). Adult birds showed higher seroprevalence than that in juvenile birds, and the presence of clinical abnormalities was associated with T. gondii seropositivity. The results showed that this pathogen has spread widely in Taiwan. This suggests the zoonotic potential of the disease, with transmission from urban to rural regions, and from terrestrial to aquatic systems. The pathogenicity of T. gondii infection in wild birds in Taiwan needs further investigation. This is the first study of the seroprevalence of T. gondii in wild birds in Taiwan.

  16. Meat Juice Serology for Toxoplasma Gondii Infection in Chickens.

    PubMed

    Vismarra, Alice; Mangia, Carlo; Barilli, Elena; Brindani, Franco; Bacci, Cristina; Kramer, Laura

    2016-01-18

    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 free-range 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.

  17. Detection of Toxoplasma gondii DNA in naturally infected sheep's milk.

    PubMed

    de Santana Rocha, D; de Sousa Moura, R L; Maciel, B M; Guimarães, L A; O'dwyer, H N S; Munhoz, A D; Albuquerque, G R

    2015-07-31

    The objective of this study was to verify whether Toxoplasma gondii is excreted in the milk of naturally infected sheep. In order to accomplish this, 275 lactating ewes were used; these were bred extensively in 17 estates distributed across nine cities. Polymerase chain reaction amplification was used to detect T. gondii DNA in milk samples, and the indirect immunofluorescence test was employed for the detection of anti-T. gondii IgG antibodies in the sera, with a cut-off value of 1:64. It was possible to verify the presence of the parasite DNA in 6.5% (18/275) of the studied animals. Anti-T. gondii antibodies were present in 41.5% of the animals studied (114/275). There was no correlation between parasite excretion in milk and the presence of IgG in 38.9% of the studied animals (7/18). The high seropositivity and the presence of parasite DNA in the milk led to the conclusion that T. gondii infection is present in the sheep population in southern and southwestern Bahia, and that there is a risk of the human population becoming infected due to the consumption of raw, in natura milk.

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

    PubMed

    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.

  19. Prevalence of Toxoplasma gondii in Canadian market-age pigs.

    PubMed

    Gajadhar, A A; Aramini, J J; Tiffin, G; Bisaillon, J R

    1998-08-01

    During 1991 and 1992, 2,800 market-age pigs were sampled at federally inspected abattoirs from across Canada. Anti-Toxoplasma gondii IgG at titers of > or =1:32 were found in 240 pigs examined by a commercial, latex agglutination test. Seroprevalences ranged from 3.5 to 13.2% in the different regions of the country. Tissue hybridization studies using a previously developed probe demonstrated T. gondii ribosomal RNA in 9 of 36 animals, whereas mouse bioassay testing of heart muscle and diaphragm from all 2,800 pigs failed to demonstrate the presence of infective stages of T. gondii in tissues. Although serology results from this study indicated that Canadian market-age pigs are infected with T. gondii at rates similar to those reported from other parts of North America, mouse bioassay results suggested that Canadian pork products contain low levels of infective organisms. This apparent discrepancy suggests that serological evidence of T. gondii infection in pigs alone does not accurately assess the public health risks associated with consuming improperly cooked pork products.

  20. Hammondia hammondi, an avirulent relative of Toxoplasma gondii, has functional orthologs of known T. gondii virulence genes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Toxoplasma gondii is a ubiquitous protozoan parasite capable of infecting all warm-blooded animals, including humans. Its closest extant relative, Hammondia hammondi, has never been found to infect humans and in contrast to T. gondii is highly attenuated in mice. To better understand the genetic bas...

  1. Toxoplasma gondii infection in lambs: high prevalence of live parasites, and genetic characterisation of T. gondii isolates revealed new genotypes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Little information is available on the presence of viable Toxoplasma gondii in tissues of lambs worldwide. The prevalence of T. gondii was determined in 383 lambs (< 1 year old) from Maryland, Virginia, and West Virginia. Hearts of 383 lambs were obtained from a slaughter house on the day of killing...

  2. Toxoplasma gondii prevalence in Israeli crows and Griffon vultures.

    PubMed

    Salant, H; Hamburger, J; King, R; Baneth, G

    2013-01-16

    A cross-sectional Toxoplasma gondii seroprevalence study was performed on free ranging crows (Corvus cornis, Corvus monedula, Corvus splendens) and Griffon vultures (Gyps fulvus) from Israel in order to assess exposure to this pathogen in scavenger birds that feed on animal carcasses and their possible role in the epidemiology of toxoplasmosis. Using the modified agglutination test (MAT) with a cutoff titer of 1:25, 52 of 122 crows (42.6%) and 40 of 101 Griffon vultures (39.6%) were found to be T. gondii seropositive. Crow T. gondii seroprevalence was significantly higher in northern areas of Israel (p=0.007) where annual precipitation is higher and annual summer maximum temperatures are lower than in the drier and warmer south. Seroprevalence in crows was positively associated with higher human population densities possibly related to the increased cat population in these areas. PCR analysis of brain extracts from crows resulted in the detection of T. gondii DNA in 1 seropositive crow from northern Israel. Genetic analysis of DNA from the positive crow brain confirmed infection with T. gondii type 2 using a multiplex multilocus nested PCR-RFLP (Mn-PCR-RFLP) of the SAG1, 5-3' SAG2, alt.SAG2, SAG3, BTUB, GRA6, C22-8, c29-2, L358, PK1 and Apico loci. The high T. gondii seroprevalence in these bird species suggests that infected carrion may be responsible for widespread infection of carcass scavenger birds which may further transmit infection to other carnivorous intermediate hosts or feline definitive hosts when consumed post-mortally.

  3. Induction of sulfadiazine resistance in vitro in Toxoplasma gondii.

    PubMed

    Doliwa, C; Escotte-Binet, S; Aubert, D; Velard, F; Schmid, A; Geers, R; Villena, I

    2013-02-01

    We induced sulfadiazine resistance in two sulfadiazine sensitive strains of Toxoplasma gondii, RH (Type I) and ME-49 (Type II) in vitro by using drug pressure. At first, sulfadiazine susceptibility of the two sensitive strains and two naturally resistant strains of T. gondii was evaluated on Vero cells using an enzyme-linked immunosorbent assay (ELISA). The IC(50) values of sulfadiazine were 77 μg/mL for RH, 51 μg/mL for ME-49 and higher than 1000 μg/mL for the two natural resistant strains. Secondly, induced resistance of the strains by gradually increase sulfadiazine concentration was verified by this test, which resulted IC(50) values at higher than 1000 μg/mL. In conclusion we developed in vitro two sulfadiazine resistant strains called RH-R(SDZ) and ME-49-R(SDZ). These strains resistant to sulfadiazine would be useful to characterize resistance mechanisms to sulfadiazine.

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

    PubMed Central

    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

  5. Toxoplasma gondii infection in two common wombats (Vombatus ursinus).

    PubMed

    Hartley, M P

    2006-03-01

    Toxoplasmosis is a common cause of death in wild and captive Australian marsupials, yet descriptions of clinical disease, diagnosis and pathological lesions are limited and incomplete. Infection with Toxoplasma gondii was diagnosed, using immunohistochemical techniques, following the acute death of a juvenile common wombat, Vombatus ursinus, that was being bottle raised by wildlife carers. This animal's cage mate developed dyspnoea, tachycardia and anorexia 3 weeks later. Serum was collected prior to euthanasia and necropsy examination. Pathological lesions in both animals were similar and toxoplasma cysts were seen in most organs examined but particularly in the neurological and respiratory systems. Serological testing of the second wombat supported the histological diagnosis and indicated that the tests have valuable roles in both diagnosing infections ante-mortem and in distinguishing between acute and chronic infections.

  6. Seroprevalence of Toxoplasma gondii antibodies in wild carnivores from Spain.

    PubMed

    Sobrino, R; Cabezón, O; Millán, J; Pabón, M; Arnal, M C; Luco, D F; Gortázar, C; Dubey, J P; Almeria, S

    2007-09-30

    Serum samples from 282 wild carnivores from different regions of Spain were tested for antibodies to Toxoplasma gondii by the modified agglutination test using a cut-off value of 1:25. Antibodies to T. gondii were found in 22 of 27 (81.5%) of Iberian lynx (Lynx pardinus), 3 of 6 European wildcats (Felis silvestris), 66 of 102 (64.7%) red foxes (Vulpes vulpes), 15 of 32 (46.9%) wolves (Canis lupus), 26 of 37 (70.3%) Eurasian badgers (Meles meles), 17 of 20 (85.0%) stone martens (Martes foina), 4 of 4 pine martens (Martes martes), 6 of 6 Eurasian otters (Lutra lutra), 4 of 4 polecats (Mustela putorius), 1 of 1 ferret (Mustela putorius furo), 13 of 21 (61.9%) European genets (Genetta genetta), and 13 of 22 (59.1%) Egyptian mongooses (Herpestes ichneumon). Serological results indicated a widespread exposure to T. gondii among wild carnivores in Spain. The high T. gondii seroprevalence in Iberian lynx and the European wildcat reported here may be of epidemiologic significance because seropositive cats might have shed oocysts.

  7. Detection of Toxoplasma gondii DNA in Brazilian oysters (Crassostrea rhizophorae).

    PubMed

    Ribeiro, L A; Santos, L K N S S; Brito, P A; Maciel, B M; Da Silva, A V; Albuquerque, G R

    2015-05-04

    The aim of this study was to detect evidence of Toxoplasma gondii using polymerase chain reaction (PCR)-based techniques in oysters (Crassostrea rhizophorae) obtained from the southern coastal region of Bahia, Brazil. A total of 624 oysters were collected, and the gills and digestive glands were dissected. Each tissue sample was separated into pools containing tissues (of the same type) from three animals, leading to a total of 416 experimental samples for analysis (208 samples each from the gills and digestive glands). Molecular analysis using PCR-based detection of the T. gondii AF 146527 repetitive fragment yielded negative results for all samples. However, when nested-PCR was used for detection of the T. gondii SAG-1 gene, 17 samples were positive, with the gills being the tissue with maximal detection of the parasite. These positive results were confirmed by sample sequencing. It is therefore suggested that C. rhizophorae oysters are capable of filtering and retaining T. gondii oocysts in their tissue. This represents a risk to public health because they are traditionally ingested in natura.

  8. On the determination of Toxoplasma gondii virulence in mice.

    PubMed

    Saraf, Pooja; Shwab, E Keats; Dubey, Jitender P; Su, Chunlei

    2017-03-01

    Toxoplasma gondii is one of the most successful pathogens on earth, capable of infecting an extremely broad range of mammals and birds and causing potentially fatal disease in humans. The house mouse (Mus musculus) has been used as the primary laboratory animal model for determining the virulence of T. gondii strains. Epidemiological evidence also suggests a potential association between virulence in mice and disease severity in human toxoplasmosis. However, many factors can affect virulence measurements, including route of infection, life stage of the parasite, number of passages of the parasite in mice or cell culture, and the mouse host line used. Variability among these factors makes it difficult to compare results between different studies in different laboratories. Here, we discuss important factors that should be considered when carrying out T. gondii murine virulence assays and propose a standardized methodology that should facilitate integration of T. gondii virulence data throughout the research community in future studies and thereby enable more efficient and effective analysis of genetic and virulence patterns for this important parasite.

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

    SciTech Connect

    Boucher, Lauren E.; Bosch, Jürgen

    2014-08-29

    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{sub 1}2{sub 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.

  10. Cross-protection induced by Toxoplasma gondii virus-like particle vaccine upon intraperitoneal route challenge.

    PubMed

    Lee, Dong-Hun; Kim, Ah-Ra; Lee, Su-Hwa; Quan, Fu-Shi

    2016-12-01

    The inner membrane complex sub-compartment has a critical role in Toxoplasma gondii endodyogeny. In this study, we investigated the protection upon intraperitoneal route (IP) challenge induced by the virus-like particles (VLPs) vaccine containing Toxoplasma gondii IMC ISP (RH strain) (Type I). Intranasal immunization with the VLPs in mice elicited enhanced systemic and mucosal Toxoplasma gondii-specific IgG, IgG1, IgG2a and IgA antibody responses, and CD4+ and CD8+ responses. Immunized mice significantly reduced T. gondii cyst burden and size in brain, resulting in cross-protection upon T. gondii (ME49) (Type II) challenge infection. These results indicate that the IP route challenge infection induced by T. gondii IMC ISP VLPs might be a very good target for vaccination representing novel approach to reduce infection.

  11. Serologic survey for Toxoplasma gondii in grizzly bears from Alaska.

    PubMed

    Zarnke, R L; Dubey, J P; Kwok, O C; Ver Hoef, J M

    1997-04-01

    Blood samples were collected from 892 grizzly bears (Ursus arctos) in Alaska (USA) from 1973 to 1987. Sera were tested for evidence of exposure to Toxoplasma gondii by means of the modified agglutination test. Two hundred twenty sera (25%) had titers > or = 25, the minimum threshold titer. Six hundred seventy-two sera (75%) had titers < 25. Antibody prevalence ranged from 9% (18 positive of 196 tested) in southern areas to 37% (162 of 433 tested) in northern areas. There was no readily apparent explanation for these discrepancies in location-specific prevalence.

  12. [Study of the effect of thiosemicarbazones against Toxoplasma gondii].

    PubMed

    Gomes, Marco Antônio G B; Carreira, Gabriela M; Souza, Daniela P V; Nogueira, Paulo Marcos R; de Melo, Edésio J T; Maria, Edmilson J

    2013-04-01

    Toxoplasmosis is a neglected disease, with an estimated occurrence of one-third of the population worldwide. Research in medicinal chemistry has for some years been pursuing the development of new drugs against toxoplasmosis, because current treatments cause serious side effects in the patient. The use of thiosemicarbazones as an alternative option for the treatment of various diseases has been published in recent years, due to their, among others, anticancer, antimalarial, antitrypanosomal, antibacterial, and antitoxoplasmosis activities, the latter being the subject of this study, which is based upon biological analyses and tests of the response of Toxoplasma gondii in the presence of thiosemicarbazones.

  13. Anti-Toxoplasma gondii antibodies in working donkeys and donkey's milk in greater Cairo, Egypt.

    PubMed

    Haridy, Fouad M; Saleh, Nagla Mostafa K; Khalil, Hazem H M; Morsy, Tosson A

    2010-08-01

    Toxoplasma gondii is one of the important zoonotic parasites of worldwide zoological & geographical distribution. ELISA prevalence of Toxoplasma gondii in Egyptian locally bred working donkeys in greater Cairo was evaluated. The donkeys were 75 females & 25 males aged between 3-10 years. The results showed that ELISA antibodies of T. gondii were found in 45 out of 100 (45%) working donkeys. Donkeys' milk obtained from fifteen pregnant females was T. gondii positive in seven (46.3%). The zoonotic role of donkeys and their milk were discussed.

  14. The Toxoplasma gondii Rhoptry Kinome Is Essential for Chronic Infection

    PubMed Central

    Fox, Barbara A.; Rommereim, Leah M.; Guevara, Rebekah B.; Falla, Alejandra; Hortua Triana, Miryam Andrea; Sun, Yanbo

    2016-01-01

    ABSTRACT    Ingestion of the obligate intracellular protozoan parasite Toxoplasma gondii causes an acute infection that leads to chronic infection of the host. To facilitate the acute phase of the infection, T. gondii manipulates the host response by secreting rhoptry organelle proteins (ROPs) into host cells during its invasion. A few key ROP proteins with signatures of kinases or pseudokinases (ROPKs) act as virulence factors that enhance parasite survival against host gamma interferon-stimulated innate immunity. However, the roles of these and other ROPK proteins in establishing chronic infection have not been tested. Here, we deleted 26 ROPK gene loci encoding 31 unique ROPK proteins of type II T. gondii and show that numerous ROPK proteins influence the development of chronic infection. Cyst burdens were increased in the Δrop16 knockout strain or moderately reduced in 11 ROPK knockout strains. In contrast, deletion of ROP5, ROP17, ROP18, ROP35, or ROP38/29/19 (ROP38, ROP29, and ROP19) severely reduced cyst burdens. Δrop5 and Δrop18 knockout strains were less resistant to host immunity-related GTPases (IRGs) and exhibited >100-fold-reduced virulence. ROP18 kinase activity and association with the parasitophorous vacuole membrane were necessary for resistance to host IRGs. The Δrop17 strain exhibited a >12-fold defect in virulence; however, virulence was not affected in the Δrop35 or Δrop38/29/19 strain. Resistance to host IRGs was not affected in the Δrop17, Δrop35, or Δrop38/29/19 strain. Collectively, these findings provide the first definitive evidence that the type II T. gondii ROPK proteome functions as virulence factors and facilitates additional mechanisms of host manipulation that are essential for chronic infection and transmission of T. gondii. PMID:27165797

  15. Neospora caninum and Toxoplasma gondii antibody prevalence in Alaska wildlife.

    PubMed

    Stieve, Erica; Beckmen, Kimberlee; Kania, Stephen A; Widner, Amanda; Patton, Sharon

    2010-04-01

    Free-ranging caribou and moose populations in some regions of Alaska undergo periodic declines in numbers. Caribou and moose are managed by the state as valuable resources for not only sustenance and subsistence, but also for cultural heritage. Incidence and prevalence of diseases that may impact herd health and recruitment from year to year are relevant to management decisions aimed to protect the long-term viability of these herds. Neospora caninum and Toxoplasma gondii are two apicomplexan parasites that can cause neurologic disease and abortions in their intermediate hosts and less frequently cause disease in their definitive hosts. The definitive hosts of N. caninum and T. gondii are canids and felids, respectively, and prevalence in the environment is in part dependent on maintenance of the life cycle through the definitive hosts. Serum samples from caribou (Rangifer tarandus, n=453), wolf (Canis lupus, n=324), moose (Alces alces, n=201), black-tailed deer (Odocoileus hemionus, n=55), coyote (Canis latrans, n=12), and fox (Vulpes vulpes, n=9) collected in Alaska were assayed for N. caninum- and T. gondii-reactive antibodies with an immunofluorescent antibody test (IFAT) and a modified agglutination test (MAT), respectively. Seroprevalence of N. caninum was greater in caribou (11.5%) than in wolves (9.0%), moose (0.5%), or black-tailed deer (0%). Seroprevalence of T. gondii was greater in wolves (17.8%) than in caribou (0.4%), moose (0%), or black-tailed deer (0%). Seroprevalence of N. caninum and T. gondii were 16.7% and 0.0% in coyotes and 0.0% and 12.5% in fox, but small sample sizes prevented further analysis. Antibodies to N. caninum in young caribou compared to adult caribou suggest that vertical transmission may be an important component of new infections in Alaskan caribou. The spatial distribution of antibody-positive individuals across Alaska may reflect differences in frequency of definitive hosts and alteration of predation patterns among regions.

  16. Pyrimidinergic Receptor Activation Controls Toxoplasma gondii Infection in Macrophages

    PubMed Central

    Moreira-Souza, Aline Cristina Abreu; Marinho, Ygor; Correa, Gladys; Santoro, Giani França; Coutinho, Claudia Mara Lara Melo; Vommaro, Rossiane Claudia; Coutinho-Silva, Robson

    2015-01-01

    Infection by the protozoan parasite Toxoplasma gondii is highly prevalent worldwide and may have serious clinical manifestations in immunocompromised patients. T. gondii is an obligate intracellular parasite that infects almost any cell type in mammalian hosts, including immune cells. The immune cells express purinergic P2 receptors in their membrane – subdivided into P2Y and P2X subfamilies - whose activation is important for infection control. Here, we examined the effect of treatment with UTP and UDP in mouse peritoneal macrophages infected with T. gondii tachyzoites. Treatment with these nucleotides reduced parasitic load by 90%, but did not increase the levels of the inflammatory mediators NO and ROS, nor did it modulate host cell death by apoptosis or necrosis. On the other hand, UTP and UDP treatments induced early egress of tachyzoites from infected macrophages, in a Ca2+-dependent manner, as shown by scanning electron microscopy analysis, and videomicroscopy. In subsequent infections, prematurely egressed parasites had reduced infectivity, and could neither replicate nor inhibit the fusion of lysosomes to the parasitophorous vacuole. The use of selective agonists and antagonists of the receptor subtypes P2Y2 and P2Y4 and P2Y6 showed that premature parasite egress may be mediated by the activation of these receptor subtypes. Our results suggest that the activity of P2Y host cell receptors controls T. gondii infection in macrophages, highlighting the importance of pyrimidinergic signaling for innate immune system response against infection. Finally the P2Y receptors should be considered as new target for the development of drugs against T. gondii infection. PMID:26192447

  17. The Rhoptry Pseudokinase ROP54 Modulates Toxoplasma gondii Virulence and Host GBP2 Loading

    PubMed Central

    Kim, Elliot W.; Nadipuram, Santhosh M.; Tetlow, Ashley L.; Barshop, William D.; Liu, Philip T.; Wohlschlegel, James A.

    2016-01-01

    ABSTRACT Toxoplasma gondii uses unique secretory organelles called rhoptries to inject an array of effector proteins into the host cytoplasm that hijack host cell functions. We have discovered a novel rhoptry pseudokinase effector, ROP54, which is injected into the host cell upon invasion and traffics to the cytoplasmic face of the parasitophorous vacuole membrane (PVM). Disruption of ROP54 in a type II strain of T. gondii does not affect growth in vitro but results in a 100-fold decrease in virulence in vivo, suggesting that ROP54 modulates some aspect of the host immune response. We show that parasites lacking ROP54 are more susceptible to macrophage-dependent clearance, further suggesting that ROP54 is involved in evasion of innate immunity. To determine how ROP54 modulates parasite virulence, we examined the loading of two known innate immune effectors, immunity-related GTPase b6 (IRGb6) and guanylate binding protein 2 (GBP2), in wild-type and ∆rop54II mutant parasites. While no difference in IRGb6 loading was seen, we observed a substantial increase in GBP2 loading on the parasitophorous vacuole (PV) of ROP54-disrupted parasites. These results demonstrate that ROP54 is a novel rhoptry effector protein that promotes Toxoplasma infections by modulating GBP2 loading onto parasite-containing vacuoles. IMPORTANCE The interactions between intracellular microbes and their host cells can lead to the discovery of novel drug targets. During Toxoplasma infections, host cells express an array of immunity-related GTPases (IRGs) and guanylate binding proteins (GBPs) that load onto the parasite-containing vacuole to clear the parasite. To counter this mechanism, the parasite secretes effector proteins that traffic to the vacuole to disarm the immunity-related loading proteins and evade the immune response. While the interplay between host IRGs and Toxoplasma effector proteins is well understood, little is known about how Toxoplasma neutralizes the GBP response. We describe

  18. Toxoplasma gondii infection in pork produced in France.

    PubMed

    Djokic, V; Blaga, R; Aubert, D; Durand, B; Perret, C; Geers, R; Ducry, T; Vallee, I; Djurkovic Djakovic, O; Mzabi, A; Villena, I; Boireau, P

    2016-04-01

    The aim of this study was to assess the seroprevalence of the Toxoplasma gondii parasite in pork produced in France, and to determine infection risk factors. An innovative survey was designed based on annual numbers of slaughtered pigs from intensive and outdoor farms in France. A total of 1549 samples of cardiac fluids were collected from pig hearts to determine seroprevalence using a Modified Agglutination Test. Of those, 160 hearts were bio-assayed in mice to isolate live parasites. The overall seroprevalence among fattening pigs was 2·9%. The adjusted seroprevalence in pigs from intensive farms was 3·0%; the highest in sows (13·4%); 2·9% in fattening pigs and 2·6% in piglets. Adjusted seroprevalence in fattening animals from outdoor farms was 6·3%. Strains were isolated from 41 animals and all were genotyped by Restriction Fragment Length Polymorphism as type II. Risk-factor analysis showed that the risk of infection was more than three times higher for outdoor pigs, and that sows' risk was almost five times higher than that of fattening animals. This study provides further evidence of extensive pork infection with T. gondii regardless of breeding systems, indicating that farm conditions are still insufficient to guarantee 'Toxoplasma-free pork'.

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

    EPA Pesticide Factsheets

    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.

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

    EPA Science Inventory

    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...

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

    EPA Science Inventory

    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...

  2. Keratoconjunctivitis associated with Toxoplasma gondii in a dog.

    PubMed

    Swinger, Robert L; Schmidt, Karl A; Dubielzig, Richard R

    2009-01-01

    A 12-year-old Pug presented with a 3-mm corneal mass OD. The dog was currently being treated for keratoconjunctivitis sicca (KCS) and pigmentary keratitis OU. A superficial keratectomy followed by cryotherapy was performed OD. A histopathologic diagnosis of epithelial dysplasia and suppurative keratitis was made and the lesion resolved. Two months later, a yellow/tan conjunctival mass, diffuse chemosis and conjunctival thickening was discovered OD. Necrotizing conjunctivitis with protozoal parasites was diagnosed with histopathology. Complete blood count and a serum biochemistry panel were normal. Neospora caninum and Toxoplasma gondii titers were negative. The conjunctivitis resolved after a 6-week course of oral clindamycin. Two months later, the patient presented with a similar conjunctival mass OS. Toxoplasma gondii was confirmed as the etiologic agent with immunohistochemical staining. Repeat T. gondii titers were negative. Oral clindamycin was re-instituted. The corneal biopsy was re-reviewed and protozoal organisms were discovered. Three months later, a recurrence was suspected and oral ponazuril was initiated for 28 days. There has been no evidence of recurrence since this treatment. Ocular toxoplasmosis is rare in the dog but reports have included episcleritis, scleritis, retinitis, anterior uveitis, ciliary epithelium hyperplasia, optic neuritis and polymyositis. To our knowledge, this is the first confirmed report of toxoplasmosis causing only corneal and conjunctival disease in the dog. We hypothesize that these localized lesions may be associated with topical immunomodulating therapy for KCS. Toxoplasmosis should be considered as a differential for canine conjunctivitis and corneal disease and has the potential to manifest in one or both eyes.

  3. Specific and nonspecific mediation of protective immunity to Toxoplasma gondii.

    PubMed Central

    Reyes, L; Frenkel, J K

    1987-01-01

    We studied the specificity of protection conferred by Toxoplasma gondii immune lymphocytes and their supernatants on infected hamster kidney cells, using Besnoitia jellisoni immune lymphocytes as a nonspecific control. The intracellular growth of the organisms was measured by [3H]uracil incorporation, and inhibition of multiplication was used as a measurement of immunity. Although the immune lymphocytes restricted principally the multiplication of homologous organisms, partial protection, expressed against the heterologous organism, was found. This was true for either parasite with intact lymphocytes or their supernatants. Exposure of immune lymphocytes to antigen for 18 to 24 h and treatment of kidney cells with supernatant fluids for 18 to 24 h were required for maximal protection. The specific protective mediator in supernatants of immune lymphocytes was characterized by dialysis as having a molecular weight between 3,000 and 12,000 and was found in the 3,000 to 5,000 peak after Sephadex G-50 chromatography. Nonspecific protective activity was greater than 12,000 by dialysis; it chromatographed in the excluded peak, measuring over 43,000, and was destroyed by exposure to pH 2. In vitro production of lymphokines from toxoplasma immune lymphocytes was first detected 7 to 10 days after vaccination of hamsters. At about the same time, hamsters began to resist challenge infection with the pathogenic RH strain of T. gondii and were able to prevent its multiplication in lungs, liver, spleen, and the subcutaneous infection site. The expression of tissue immunity and the production of toxoplasma-immune lymphokines appear to be time-related events. PMID:3557619

  4. Further evidence that naphthoquinone inhibits Toxoplasma gondii growth in vitro.

    PubMed

    da Silva, Luciana Lemos Rangel; Portes, Juliana de Araujo; de Araújo, Marlon Heggdorne; Silva, Jéssica Lays Sant'ana; Rennó, Magdalena Nascimento; Netto, Chaquip Daher; da Silva, Alcides José Monteiro; Costa, Paulo Roberto Ribeiro; De Souza, Wanderley; Seabra, Sergio Henrique; DaMatta, Renato Augusto

    2015-12-01

    Toxoplasmosis is a widely disseminated disease caused by Toxoplasma gondii, an intracellular protozoan parasite. Standard treatment causes many side effects, such as depletion of bone marrow cells, skin rashes and gastrointestinal implications. Therefore, it is necessary to find chemotherapeutic alternatives for the treatment of this disease. It was shown that a naphthoquinone derivative compound is active against T. gondii, RH strain, with an IC50 around 2.5 μM. Here, three different naphthoquinone derivative compounds with activity against leukemia cells and breast carcinoma cell were tested against T. gondii (RH strain) infected LLC-MK2 cell line. All the compounds were able to inhibit parasite growth in vitro, but one of them showed an IC50 activity below 1 μM after 48 h of treatment. The compounds showed low toxicity to the host cell. In addition, these compounds were able to induce tachyzoite-bradyzoite conversion confirmed by morphological changes, Dolichus biflorus lectin cyst wall labeling and characterization of amylopectin granules in the parasites by electron microscopy analysis using the Thierry technique. Furthermore, the compounds induced alterations on the ultrastructure of the parasite. Taken together, our results point to the naphthoquinone derivative (LQB 151) as a potential compound for the development of new drugs for the treatment of toxoplasmosis.

  5. Detection of Toxoplasma gondii antibodies in Antarctic pinnipeds.

    PubMed

    Rengifo-Herrera, Claudia; Ortega-Mora, Luis Miguel; Alvarez-García, Gema; Gómez-Bautista, Mercedes; García-Párraga, Daniel; García-Peña, Francisco Javier; Pedraza-Díaz, Susana

    2012-11-23

    The presence of Toxoplasma gondii antibodies was investigated in Antarctic marine mammals. Two hundred and eleven sera from different species of pinnipeds collected in years 2007, 2010 and 2011 from different locations in the South Shetland Islands and Antarctic Peninsula were analysed using a commercially available agglutination test kit. The presence of antibodies (titres ≥ 1:25) against T. gondii was detected in a total of 28 animals (13.3%). Amongst animal species, percentages of detection were higher in Southern elephant seals (Mirounga leonina) (76.9%; 10/13) followed by Weddell seals (Leptonychotes weddellii) (41.9%; 13/31). Antibodies were also found in 4 of 165 (2.4%) Antarctic fur seals (Arctocephalus gazella) and 1 of 2 Crabeater seals (Lobodon carcinophaga). Highest titres (1:100-1:800) were also observed in Southern elephant seals and Weddell seals. To the best of our knowledge this is the first report on the detection of antibodies against T. gondii in Antarctic marine mammals.

  6. Identifying Novel B Cell Epitopes within Toxoplasma gondii GRA6

    PubMed Central

    Wang, Yanhua; Wang, Guangxiang; Cai, Jian Ping

    2016-01-01

    The study of antigenic epitopes from Toxoplasma gondii has not only enhanced our understanding of the structure and function of antigens, the reactions between antigens and antibodies, and many other aspects of immunology, but it also plays a significant role in the development of new diagnostic reagents and vaccines. In the present study, T. gondii GRA6 epitopes were identified using bioinformatics tools and a synthetic peptide technique. The potential B cell epitopes of GRA6 predicted by bioinformatics tools concentrated upon 3 regions of GRA6, 1-20 aa, 44-103 aa, and 172-221 aa. Ten shorter peptides from the 3 regions were synthesized and assessed by ELISA using pig sera from different time points after infection. Three of the 10 peptides (amino acids 44-63, 172-191, and 192-211) tested were recognized by all sera and determined to be immunodominant B-cell epitopes of GRA6. The results indicated that we precisely and accurately located the T. gondii GRA6 epitopes using pig sera collected at different time points after infection. The identified epitopes may be very useful for further studies of epitope-based vaccines and diagnostic reagents. PMID:27658594

  7. Seroprevalence of Toxoplasma gondii Infection in Police Dogs in Shenyang, Northeastern China

    PubMed Central

    Liu, Cheng-Wu; He, Jian-Bin; Mu, Ming-Yang; Yang, Min; Sun, Ning; Li, Hong-Kui

    2013-01-01

    In recent years, worldwide surveys of Toxoplasma gondii infection in dogs have been reported. However, only limited surveys of T. gondii infection in police dogs have been available, including China. In the present study, we report the seroprevalence of T. gondii in police dogs in Shenyang, northeastern China. Sera from 291 police dogs were examined for T. gondii antibodies with the modified agglutination test (MAT), and 30.9% animals were tested seropositive. The results of the present study indicated a relatively high prevalence of T. gondii infection in police dogs in Shenyang, China. PMID:24327786

  8. The Apoptotic Role of Metacaspase in Toxoplasma gondii.

    PubMed

    Li, Muzi; Wang, Hui; Liu, Jing; Hao, Pan; Ma, Lei; Liu, Qun

    2015-01-01

    Toxoplasma gondii is a major opportunistic pathogen that spreads in a range of animal species and human beings. Quite a few characterizations of apoptosis have been identified in T. gondii treated with apoptosis inducers, but the molecular mechanisms of the pathway are not clearly understood. Metacaspases are caspase-like cysteine proteases that can be found in plants, fungi, and protozoa in which caspases are absent. Metacaspases are multifunctional proteases involved in apoptosis-like cell death, insoluble protein aggregate clearance, and cell proliferation. To investigate whether T. gondii metacaspase (TgMCA) is involved in the apoptosis of the parasites, we generated TgMCA mutant strains. Western blot analysis indicated that the autoproteolytic processing of TgMCA was the same as that for metacaspases of some other species. Indirect immunofluorescence assay (IFA) showed that TgMCA was dispersed throughout the cytoplasm and relocated to the nucleus when the parasites were exposed to the extracellular environment, which indicated the execution of its function in the nucleus. The number of apoptosis parasites was significantly diminished in the TgMCA knockout strain and increased in the TgMCA overexpression strain after treatment with extracellular buffer, as determined by the terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. The lack of TgMCA did not affect the parasite propagation in vitro and virulence in vivo, suggesting that it is probably redundant in parasite propagation. But overexpression of TgMCA reduced the intracellular parasites growth in vitro. The TgMCA knockout strain showed more viability in extracellular buffer compared to the parental and overexpression lines. In this study, we demonstrated that TgMCA contributes to the apoptosis of T. gondii.

  9. The Apoptotic Role of Metacaspase in Toxoplasma gondii

    PubMed Central

    Li, Muzi; Wang, Hui; Liu, Jing; Hao, Pan; Ma, Lei; Liu, Qun

    2016-01-01

    Toxoplasma gondii is a major opportunistic pathogen that spreads in a range of animal species and human beings. Quite a few characterizations of apoptosis have been identified in T. gondii treated with apoptosis inducers, but the molecular mechanisms of the pathway are not clearly understood. Metacaspases are caspase-like cysteine proteases that can be found in plants, fungi, and protozoa in which caspases are absent. Metacaspases are multifunctional proteases involved in apoptosis-like cell death, insoluble protein aggregate clearance, and cell proliferation. To investigate whether T. gondii metacaspase (TgMCA) is involved in the apoptosis of the parasites, we generated TgMCA mutant strains. Western blot analysis indicated that the autoproteolytic processing of TgMCA was the same as that for metacaspases of some other species. Indirect immunofluorescence assay (IFA) showed that TgMCA was dispersed throughout the cytoplasm and relocated to the nucleus when the parasites were exposed to the extracellular environment, which indicated the execution of its function in the nucleus. The number of apoptosis parasites was significantly diminished in the TgMCA knockout strain and increased in the TgMCA overexpression strain after treatment with extracellular buffer, as determined by the terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. The lack of TgMCA did not affect the parasite propagation in vitro and virulence in vivo, suggesting that it is probably redundant in parasite propagation. But overexpression of TgMCA reduced the intracellular parasites growth in vitro. The TgMCA knockout strain showed more viability in extracellular buffer compared to the parental and overexpression lines. In this study, we demonstrated that TgMCA contributes to the apoptosis of T. gondii. PMID:26834715

  10. Sporulation and survival of Toxoplasma gondii oocysts in seawater

    USGS Publications Warehouse

    Lindsay, D.S.; Collins, M.V.; Mitchell, S.M.; Cole, R.A.; Flick, G.J.; Wetch, C.N.; Lindquist, A.; Dubey, J.P.

    2003-01-01

    We have been collaborating since 1992 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 otters. We postulated that cat feces containing oocysts could be entering the marine environment through storm run-off or through municipal sewage since cat feces are often disposed down toilets by cat owners. The present study examined the sporulation of T. gondii oocysts in seawater and the survival of sporulated oocysts in seawater. Unsporulated oocysts were placed in 15 ppt artificial seawater, 32 ppt artificial seawater or 2% sulfuric acid (positive control) at 24 C in an incubator. Samples were examined daily for 3 days and development monitored by counting 100 oocysts from each sample. From 75 to 80% of the oocysts were sporulated by 3 days post-inoculation under all treatment conditions. Groups of 2 mice were fed 10,000 oocysts each from each of the 3 treatment groups. All inoculated mice developed toxoplasmosis indicating that oocysts were capable of sporulating in seawater. Survival of sporulated oocysts was examined by placing sporulated T. gondii oocysts in 15 ppt seawater at room temperature 22a??24 C (RT) or in a refrigerator kept at 4 C. Mice fed oocysts that had been stored at 4C or RT for 6 months became infected. These results indicate that T. gondii oocysts can sporulate and remain viable in seawater for several months.

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

    EPA Science Inventory

    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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Toxoplasma gondii is the most common parasite that contaminates produce. However as more cases of T. gondii contamination are being linked to produce, current washing steps in produce processing may not be effective or suitable for some varieties of produce. The objective of this study was to eva...

  13. Effects of ozone and UV radiation treatments on the infectivity of Toxoplasma gondii oocysts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Clinical toxoplasmosis in humans has been epidemiologically-linked to the consumption of drinking water contaminated by Toxoplasma gondii oocysts. We evaluated killing of T. gondii oocysts after ultraviolet (UV) or ozone treatments by bioassay in mice and/or cell culture. A 4-log inactivation of the...

  14. Detection of Toxoplasma gondii oocysts in water sample concentrates by real-time PCR

    Technology Transfer Automated Retrieval System (TEKTRAN)

    PCR techniques in combination with conventional parasite concentration procedures have potential for sensitive and specific detection of Toxoplasma gondii oocysts in water. Three real-time PCR assays based on the B1 gene and a 529-bp repetitive element were compared for detection of T. gondii tachyz...

  15. ISOLATION OF TOXOPLASMA GONDII FROM CAPYBARAS (HYDROCHAERIS HYDROCHAERIS) FROM SÃO PAULO STATE, BRAZIL

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Capybara (Hydrochaeris hydrochaeris) is a large rodent used for human consumption in certain areas of South America. In the present study, viable Toxoplasma gondii was isolated for the first time from this host. Antibodies to T. gondii were assayed in the sera of 64 capybaras from 6 counties of São...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The consumption of unpasteurized goat cheese and 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. Eight goats were inoculated orally with 300-10000 oocysts of T. gondii strain TgGoa...

  18. Inactivation of Toxoplasma gondii on Blueberries using Low Dose Irradiation without Affecting Quality.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 ...

  19. Development of the dose-response relationship for human toxoplasma gondii infection associated with meat consumption

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Toxoplasma gondii is a protozoan parasite that is responsible for approximately 24% of deaths attributed to foodborne pathogens in the United States.A substantial portion of human T. gondii infections may be acquired through the consumption of meats. The dose-response relationship for human exposure...

  20. A systematic meta-analysis of Toxoplasma gondii prevalence in meat animals in the United States

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Toxoplasma gondii is a widely distributed protozoan parasite. The Centers for Disease Control and Prevention (CDC) reported that T. gondii is one of three pathogens (along with Salmonella and Listeria), which together account for >70% of all deaths due to foodborne illness in the United States. Meat...

  1. Isolation and genetic characterization of Toxoplasma gondii in the mongoose (Herpestes auropunctatus) in Grenada, West Indies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Little is known of the genetic diversity and epidemiology of Toxoplasma gondii infection in wildlife in Caribbean Islands. Here, we investigated prevalence and genetic diversity of T. gondii in mongooses (Herpestes auropunctatus). During 2011 and 2012, 91 mongooses were trapped in different parts of...

  2. Functional conservation of Toxoplasma gondii virulence genes in its avirulent relative, Hammondia hammondi

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Toxoplasma gondii is a ubiquitous protozoan parasite capable of infecting all warm blooded animals, including humans. Its closest extant relative, Hammondia hammondi, has never been found to infect humans and in contrast to T. gondii is highly attenuated in mice. To better understand the genetic b...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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. Seroprevalence of Toxoplasma Gondii infection in domestic horses in Durango State, Mexico

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The seroprevalence of Toxoplasma gondii infection in horses in Mexico is unknown. Therefore, antibodies to T. gondii were determined in 495 horses in Durango State, Mexico using the modified agglutination test (MAT). Horses were from 18 farms in 3 municipalities in the valley region of Durango State...

  5. Seroprevalence and isolation of viable Toxoplasma gondii from raptors in the southeastern USA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Raptors are good indicators of the prevalence of Toxoplasma gondii in the environment because they prey on small mammals and birds. These prey species are a major source of infection in felids, which shed the environmentally resistant oocysts. We assessed T. gondii infection in 281 opportunistically...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  7. Genetic characterization of viable Toxoplasma gondii isolates from stray dogs from Giza, Egypt

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Stray dogs are considered as sentinels in the epidemiology of Toxoplasma gondii because they are carnivores and eat variety of foods, including garbage. In the present study, tissues and sera of 51 stray dogs (Canis familiaris) from Giza, Egypt were examined for T. gondii infection. Sera were examin...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 ...

  9. Determining Resistance of Toxoplasma gondii Oocysts to UV Disinfection Using Cell Culture and a Mouse Bioassay

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  10. Prevalence and genetic characterization of Toxoplasma gondii in bats in Myanmar.

    PubMed

    Sun, Hongchao; Wang, Yiyin; Zhang, Yingguang; Ge, Wei; Zhang, Fuqiang; He, Biao; Li, Zuosheng; Fan, Quanshui; Wang, Wei; Tu, Changchun; Li, Jiping; Liu, Quan

    2013-06-01

    We detected Toxoplasma gondii in 29.3% (95% confidence interval [CI], 25.5% to 33.1%) of 550 insectivorous bats collected in Myanmar. The genotyping of these positive samples revealed they were closely related to or belong to clonal type I, which is highly virulent in mice, showing that these bats are potential reservoirs for T. gondii transmission.

  11. Toxoplasma gondii isolates from mouflon sheep (Ovis ammon) from Hawaii, USA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Little is known of Toxoplasma gondii isolates circulating in wildlife. The mouflon (Ovis ammon) is very popular game animal, hunted for its trophy horns. Here, we report the isolation and genetic characterization of T. gondii from two mouflon from Hawaii, USA. Both sheep had antibodies titers of 1: ...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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) ...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Toxoplasma gondii is an obligate intracellular protozoan pathogen that commonly infects humans. To date, research on understanding the prevalence of T. gondii oocysts in the water and environment are limited due to the lack of tools to detect oocysts in the environment. This is primarily due to the...

  14. PREVALENCE OF ANTIBODIES TO TOXOPLASMA GONDII IN WOLVERINES FROM NUNAVUT, CANADA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The prevalence of antibodies to Toxoplasma gondii was determined in blood and tissue exudates recovered from the spleens of 41 wolverines (Gulo gulo) collected in Nunavut, Canada using a modified agglutination test (MAT). Antibodies to T. gondii were found in 17 (41.5%) of the 41 wolverines with MAT...

  15. Seroprevalence of Toxoplasma gondii infection in domestic pigs in Durango State, Mexico

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Little is known concerning the prevalence of Toxoplasma gondii infection in pigs in Mexico. Antibodies to T. gondii were determined in 1,077 domestic pigs in Durango, Mexico using the modified agglutination test (MAT). Two groups (A, B) of pigs were sampled: Group A pigs (n=555) were raised in 3 geo...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The seroprevalence of Toxoplasma gondii infection in sheep 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....

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Little is known concerning the seroprevalence of Toxoplasma gondii infection in goats in Mexico. Antibodies to T. gondii were determined in 562 goats in Durango, Mexico using the modified agglutination test. Goats were raised in 12 farms in two geographical regions: semi-desert (n=70) and mountains ...

  19. Isolation of Viable Toxoplasma gondii from Tissues and Feces of Cats from Addis Ababa, Ethiopia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cats are important in the epidemiology of Toxoplasma gondii because they are the only hosts that excrete environmentally resistant oocysts in feces. In the present study, hearts, serum, and feces from 36 feral cats from Addis Ababa area, Ethiopia were examined for T. gondii infection. Antibodies to ...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  1. Seroprevalence of toxoplasma gondii infection in domestic rabbits in Durango State, Mexico

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Toxoplasma gondii infection in rabbits is of public health importance because rabbit meat is consumed by humans, and rabbits are preyed upon by cats that then shed environmentally resistant oocysts. Antibodies to T. gondii were determined in 429 domestic rabbits in Durango State, Mexico using the mo...

  2. Prevalence of anti-Toxoplasma gondii antibodies in sport horses from Qazvin, Iran.

    PubMed

    Hajialilo, Elham; Ziaali, Naser; Harandi, Majid Fasihi; Saraei, Mehrzad; Hajialilo, Mohammad

    2010-10-01

    In the present study, the prevalence of antibodies to Toxoplasma gondii in sport horses of Qazvin was examined using modified agglutination test (MAT). On 52 horse sera totally examined for anti-Toxoplasma antibodies, 37 horses (71.2%) were seropositive by MAT. Results of the present study showed a high rate of Toxoplasma infection in horses in Qazvin area. More comprehensive study on equine toxoplasmosis is recommended.

  3. Extended epigenotype in a Rattus novergicus - Toxoplasma gondii association.

    PubMed

    Vyas, Ajai

    2015-01-01

    Several studies demonstrate that rats (Rattus novergicus) infected with protozoan parasite Toxoplasma gondii exhibit lesser fear to cat odors. This is thought to increase transmission of the parasite to its definitive hosts, i.e. cats. This is an example of extended phenotype where a gene of an organism allegedly creates a phenotype in another organism. We examined a possible proximate mechanism for this phenotype, describing an epigenetic change in arginine vasopressin gene in medial amygdala of male rats. Exogenously mimicking medial amygdala DNA hypomethylation resulted in reduction of fear to cat odors in uninfected animals, thus suggesting sufficiency. Systemic blockade of infection-induced DNA hypomethylation countermanded infection-induced behavioral change, thus suggesting necessity. This leads us to propose an epigenetic basis for this extended phenotype.

  4. Human Toxoplasma gondii-specific secretory immunoglobulin A reduces T. gondii infection of enterocytes in vitro.

    PubMed Central

    Mack, D G; McLeod, R

    1992-01-01

    Whey from 17 women (four acutely infected with Toxoplasma gondii, eight chronically infected, and five uninfected) was studied. T. gondii-specific secretory IgA antibodies were demonstrated by ELISA in whey from acutely infected and one of eight chronically infected women. Such antibodies to tachyzoite proteins of < or = 14, 22, 26-28, 30, 46, 60, 70-80, and > 100 kD (eliminated by protease but not periodate or neuraminidase treatment) were demonstrated in whey from acutely infected subjects when Western blots were probed with their whey and antibodies to human secretory IgA or IgA or secretory piece. Secretory IgA from four of eight chronically infected women recognized the 46- and 69-kD epitopes. Other whey samples were negative. Incubation of T. gondii tachyzoites with whey or purified secretory IgA from acutely infected (but not seronegative) women caused 50-75% reduction in infection of enterocytes in vitro. Whey reactive with the 46-kD epitope from three of six chronically infected women caused less (> or = 40%) inhibition. Whey and purified secretory IgA from two of three acutely infected women agglutinated tachyzoites. Whey did not result in complement-dependent lysis of T. gondii. These results indicate that it may be possible to produce human secretory IgA to T. gondii capable of reducing initial infection of enterocytes, as such IgA is present during natural infection. They also demonstrate candidate epitopes for such protection. Images PMID:1469104

  5. Drug Repurposing Screening Identifies Novel Compounds That Effectively Inhibit Toxoplasma gondii Growth

    PubMed Central

    Dittmar, Ashley J.; Drozda, Allison A.

    2016-01-01

    ABSTRACT The urgent need to develop new antimicrobial therapies has spawned the development of repurposing screens in which well-studied drugs and other types of compounds are tested for potential off-label uses. As a proof-of-principle screen to identify compounds effective against Toxoplasma gondii, we screened a collection of 1,120 compounds for the ability to significantly reduce Toxoplasma replication. A total of 94 compounds blocked parasite replication with 50% inhibitory concentrations of <5 µM. A significant number of these compounds are established inhibitors of dopamine or estrogen signaling. Follow-up experiments with the dopamine receptor inhibitor pimozide revealed that the drug impacted both parasite invasion and replication but did so independently of inhibition of dopamine or other neurotransmitter receptor signaling. Tamoxifen, which is an established inhibitor of the estrogen receptor, also reduced parasite invasion and replication. Even though Toxoplasma can activate the estrogen receptor, tamoxifen inhibits parasite growth independently of this transcription factor. Tamoxifen is also a potent inducer of autophagy, and we find that the drug stimulates recruitment of the autophagy marker light chain 3-green fluorescent protein onto the membrane of the vacuolar compartment in which the parasite resides and replicates. In contrast to other antiparasitic drugs, including pimozide, tamoxifen treatment of infected cells leads to a time-dependent elimination of intracellular parasites. Taken together, these data suggest that tamoxifen restricts Toxoplasma growth by inducing xenophagy or autophagic destruction of this obligate intracellular parasite. IMPORTANCE There is an urgent need to develop new therapies to treat microbial infections, and the repurposing of well-characterized compounds is emerging as one approach to achieving this goal. Using the protozoan parasite Toxoplasma gondii, we screened a library of 1,120 compounds and identified several

  6. The Crystal Structure of Toxoplasma gondii Pyruvate Kinase 1

    SciTech Connect

    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.

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

    PubMed Central

    Gharadaghi, Yaghub; Shojaee, Saeedeh; Khaki, Arash; Hatef, Amir; Ahmadi Ashtiani, Hamid Reza; Rastegar, Hossin; Fathiazad, Fatemeh

    2012-01-01

    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. PMID:24312764

  8. Toxoplasma gondii Infections Alter GABAergic Synapses and Signaling in the Central Nervous System

    PubMed Central

    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

  9. T. GONDII IN FREE-RANGE CHICKENS SEROPREVALENCE AND ISOLATION OF TOXOPLASMA GONDII FROM FREE-RANGE CHICKENS FROM GHANA, INDONESIA, ITALY, POLAND, AND VIETNAM

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The prevalence of Toxoplasma gondii in free-ranging chickens is a good indicator of the prevalence of T. gondii oocysts in soil because chickens feed from the ground. The prevalence of T. gondii in free-range chickens (Gallus domesticus) from Ghana, Indonesia, Italy, Poland, and Vietnam was determin...

  10. Genetic diversity among sea otter isolates of Toxoplasma gondii

    USGS Publications Warehouse

    Sundar, N.; Cole, R.A.; Thomas, N.J.; Majumdar, D.; Dubey, J.P.; Su, C.

    2008-01-01

    Sea otters (Enhydra lutris) have been reported to become infected with Toxoplasma gondii and at times succumb to clinical disease. Here, we determined genotypes of 39 T. gondii isolates from 37 sea otters in two geographically distant locations (25 from California and 12 from Washington). Six genotypes were identified using 10 PCR-RFLP genetic markers including SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico, and by DNA sequencing of loci SAG1 and GRA6 in 13 isolates. Of these 39 isolates, 13 (33%) were clonal Type II which can be further divided into two groups at the locus Apico. Two of the 39 isolates had Type II alleles at all loci except a Type I allele at locus L358. One isolate had Type II alleles at all loci except the Type I alleles at loci L358 and Apico. One isolate had Type III alleles at all loci except Type II alleles at SAG2 and Apico. Two sea otter isolates had a mixed infection. Twenty-one (54%) isolates had an unique allele at SAG1 locus. Further genotyping or DNA sequence analysis for 18 of these 21 isolates at loci SAG1 and GRA6 revealed that there were two different genotypes, including the previously identified Type X (four isolates) and a new genotype named Type A (14 isolates). The results from this study suggest that the sea otter isolates are genetically diverse.

  11. Inhibition and Structure of Toxoplasma gondii Purine Nucleoside Phosphorylase

    PubMed Central

    Donaldson, Teraya M.; Cassera, María B.; Ho, Meng-Chiao; Zhan, Chenyang; Merino, Emilio F.; Evans, Gary B.; Tyler, Peter C.; Almo, Steven C.; Schramm, Vern L.

    2014-01-01

    The intracellular pathogen Toxoplasma gondii is a purine auxotroph that relies on purine salvage for proliferation. We have optimized T. gondii purine nucleoside phosphorylase (TgPNP) stability and crystallized TgPNP with phosphate and immucillin-H, a transition-state analogue that has high affinity for the enzyme. Immucillin-H bound to TgPNP with a dissociation constant of 370 pM, the highest affinity of 11 immucillins selected to probe the catalytic site. The specificity for transition-state analogues indicated an early dissociative transition state for TgPNP. Compared to Plasmodium falciparum PNP, large substituents surrounding the 5′-hydroxyl group of inhibitors demonstrate reduced capacity for TgPNP inhibition. Catalytic discrimination against large 5′ groups is consistent with the inability of TgPNP to catalyze the phosphorolysis of 5′-methylthioinosine to hypoxanthine. In contrast to mammalian PNP, the 2′-hydroxyl group is crucial for inhibitor binding in the catalytic site of TgPNP. This first crystal structure of TgPNP describes the basis for discrimination against 5′-methylthioinosine and similarly 5′-hydroxy-substituted immucillins; structural differences reflect the unique adaptations of purine salvage pathways of Apicomplexa. PMID:24585883

  12. Guanylate binding proteins directly attack Toxoplasma gondii via supramolecular complexes.

    PubMed

    Kravets, Elisabeth; Degrandi, Daniel; Ma, Qijun; Peulen, Thomas-Otavio; Klümpers, Verena; Felekyan, Suren; Kühnemuth, Ralf; Weidtkamp-Peters, Stefanie; Seidel, Claus Am; Pfeffer, Klaus

    2016-01-27

    GBPs are essential for immunity against intracellular pathogens, especially for Toxoplasma gondii control. Here, the molecular interactions of murine GBPs (mGBP1/2/3/5/6), homo- and hetero-multimerization properties of mGBP2 and its function in parasite killing were investigated by mutational, Multiparameter Fluorescence Image Spectroscopy, and live cell microscopy methodologies. Control of T. gondii replication by mGBP2 requires GTP hydrolysis and isoprenylation thus, enabling reversible oligomerization in vesicle-like structures. mGBP2 undergoes structural transitions between monomeric, dimeric and oligomeric states visualized by quantitative FRET analysis. mGBPs reside in at least two discrete subcellular reservoirs and attack the parasitophorous vacuole membrane (PVM) as orchestrated, supramolecular complexes forming large, densely packed multimers comprising up to several thousand monomers. This dramatic mGBP enrichment results in the loss of PVM integrity, followed by a direct assault of mGBP2 upon the plasma membrane of the parasite. These discoveries provide vital dynamic and molecular perceptions into cell-autonomous immunity.

  13. Characterization of the Chloroquine Resistance Transporter Homologue in Toxoplasma gondii

    PubMed Central

    Warring, Sally D.; Dou, Zhicheng; Carruthers, Vern B.; McFadden, Geoffrey I.

    2014-01-01

    Mutations in the Plasmodium falciparum chloroquine resistance transporter (PfCRT) protein confer resistance to the antimalarial drug chloroquine. PfCRT localizes to the parasite digestive vacuole, the site of chloroquine action, where it mediates resistance by transporting chloroquine out of the digestive vacuole. PfCRT belongs to a family of transporter proteins called the chloroquine resistance transporter family. CRT family proteins are found throughout the Apicomplexa, in some protists, and in plants. Despite the importance of PfCRT in drug resistance, little is known about the evolution or native function of CRT proteins. The apicomplexan parasite Toxoplasma gondii contains one CRT family protein. We demonstrate that T. gondii CRT (TgCRT) colocalizes with markers for the vacuolar (VAC) compartment in these parasites. The TgCRT-containing VAC is a highly dynamic organelle, changing its morphology and protein composition between intracellular and extracellular forms of the parasite. Regulated knockdown of TgCRT expression resulted in modest reduction in parasite fitness and swelling of the VAC, indicating that TgCRT contributes to parasite growth and VAC physiology. Together, our findings provide new information on the role of CRT family proteins in apicomplexan parasites. PMID:24859994

  14. Guanylate binding proteins directly attack Toxoplasma gondii via supramolecular complexes

    PubMed Central

    Kravets, Elisabeth; Degrandi, Daniel; Ma, Qijun; Peulen, Thomas-Otavio; Klümpers, Verena; Felekyan, Suren; Kühnemuth, Ralf; Weidtkamp-Peters, Stefanie; Seidel, Claus AM; Pfeffer, Klaus

    2016-01-01

    GBPs are essential for immunity against intracellular pathogens, especially for Toxoplasma gondii control. Here, the molecular interactions of murine GBPs (mGBP1/2/3/5/6), homo- and hetero-multimerization properties of mGBP2 and its function in parasite killing were investigated by mutational, Multiparameter Fluorescence Image Spectroscopy, and live cell microscopy methodologies. Control of T. gondii replication by mGBP2 requires GTP hydrolysis and isoprenylation thus, enabling reversible oligomerization in vesicle-like structures. mGBP2 undergoes structural transitions between monomeric, dimeric and oligomeric states visualized by quantitative FRET analysis. mGBPs reside in at least two discrete subcellular reservoirs and attack the parasitophorous vacuole membrane (PVM) as orchestrated, supramolecular complexes forming large, densely packed multimers comprising up to several thousand monomers. This dramatic mGBP enrichment results in the loss of PVM integrity, followed by a direct assault of mGBP2 upon the plasma membrane of the parasite. These discoveries provide vital dynamic and molecular perceptions into cell-autonomous immunity. DOI: http://dx.doi.org/10.7554/eLife.11479.001 PMID:26814575

  15. Mitochondrial behaviour throughout the lytic cycle of Toxoplasma gondii.

    PubMed

    Ovciarikova, Jana; Lemgruber, Leandro; Stilger, Krista L; Sullivan, William J; Sheiner, Lilach

    2017-02-16

    Mitochondria distribution in cells controls cellular physiology in health and disease. Here we describe the mitochondrial morphology and positioning found in the different stages of the lytic cycle of the eukaryotic single-cell parasite Toxoplasma gondii. The lytic cycle, driven by the tachyzoite life stage, is responsible for acute toxoplasmosis. It is known that whilst inside a host cell the tachyzoite maintains its single mitochondrion at its periphery. We found that upon parasite transition from the host cell to the extracellular matrix, mitochondrion morphology radically changes, resulting in a reduction in peripheral proximity. This change is reversible upon return to the host, indicating that an active mechanism maintains the peripheral positioning found in the intracellular stages. Comparison between the two states by electron microscopy identified regions of coupling between the mitochondrion outer membrane and the parasite pellicle, whose features suggest the presence of membrane contact sites, and whose abundance changes during the transition between intra- and extra-cellular states. These novel observations pave the way for future research to identify molecular mechanisms involved in mitochondrial distribution in Toxoplasma and the consequences of these mitochondrion changes on parasite physiology.

  16. Mitochondrial behaviour throughout the lytic cycle of Toxoplasma gondii

    PubMed Central

    Ovciarikova, Jana; Lemgruber, Leandro; Stilger, Krista L.; Sullivan, William J.; Sheiner, Lilach

    2017-01-01

    Mitochondria distribution in cells controls cellular physiology in health and disease. Here we describe the mitochondrial morphology and positioning found in the different stages of the lytic cycle of the eukaryotic single-cell parasite Toxoplasma gondii. The lytic cycle, driven by the tachyzoite life stage, is responsible for acute toxoplasmosis. It is known that whilst inside a host cell the tachyzoite maintains its single mitochondrion at its periphery. We found that upon parasite transition from the host cell to the extracellular matrix, mitochondrion morphology radically changes, resulting in a reduction in peripheral proximity. This change is reversible upon return to the host, indicating that an active mechanism maintains the peripheral positioning found in the intracellular stages. Comparison between the two states by electron microscopy identified regions of coupling between the mitochondrion outer membrane and the parasite pellicle, whose features suggest the presence of membrane contact sites, and whose abundance changes during the transition between intra- and extra-cellular states. These novel observations pave the way for future research to identify molecular mechanisms involved in mitochondrial distribution in Toxoplasma and the consequences of these mitochondrion changes on parasite physiology. PMID:28202940

  17. Quinolone-based drugs against Toxoplasma gondii and Plasmodium spp.

    PubMed

    Anquetin, Guillaume; Greiner, Jacques; Vierling, Pierre

    2005-09-01

    Owing to the rapid emergence of multi-resistant strains of Plasmodium spp. (the causative agents of malaria) and the limitations of drugs used against Toxoplasma gondii (an important opportunistic pathogen associated with AIDS and congenital birth defects), the discovery of new therapeutical targets and the development of new drugs are needed. The presence of the prokaryotic-like organelle in apicomplexan parasites (i.e. plastids), which comprise these major human pathogens, may represent a unique target for antibiotics against these protozoa. Quinolones which are known to be highly potent against bacteria were also found to specifically disrupt these parasites. They inhibit DNA replication by interacting with two essential bacterial type II topoisomerases, DNA gyrase and topoisomerase IV. There are some clues that quinolones act on plastids with a similar mechanism of action. After a brief presentation of plasmodium and toxoplasma dedicated to their life cycle, the chemotherapies presently used in clinics to fight against these protozoa and the potential new targets and drugs, we will focus our attention on their plastid which is one of these promising new targets. Then, we will present the various drugs and generations of quinolones, the leading molecules, and their inhibitory effects against these parasites together with their pharmacological properties that have been established from in vitro and in vivo studies. We will also discuss their possible mode of action.

  18. Lipid kinases are essential for apicoplast homeostasis in Toxoplasma gondii.

    PubMed

    Daher, Wassim; Morlon-Guyot, Juliette; Sheiner, Lilach; Lentini, Gaëlle; Berry, Laurence; Tawk, Lina; Dubremetz, Jean-François; Wengelnik, Kai; Striepen, Boris; Lebrun, Maryse

    2015-04-01

    Phosphoinositides regulate numerous cellular processes by recruiting cytosolic effector proteins and acting as membrane signalling entities. The cellular metabolism and localization of phosphoinositides are tightly regulated by distinct lipid kinases and phosphatases. Here, we identify and characterize a unique phosphatidylinositol 3 kinase (PI3K) in Toxoplasma gondii, a protozoan parasite belonging to the phylum Apicomplexa. Conditional depletion of this enzyme and subsequently of its product, PI(3)P, drastically alters the morphology and inheritance of the apicoplast, an endosymbiotic organelle of algal origin that is a unique feature of many Apicomplexa. We searched the T. gondii genome for PI(3)P-binding proteins and identified in total six PX and FYVE domain-containing proteins including a PIKfyve lipid kinase, which phosphorylates PI(3)P into PI(3,5)P2 . Although depletion of putative PI(3)P-binding proteins shows that they are not essential for parasite growth and apicoplast biology, conditional disruption of PIKfyve induces enlarged apicoplasts, as observed upon loss of PI(3)P. A similar defect of apicoplast homeostasis was also observed by knocking down the PIKfyve regulatory protein ArPIKfyve, suggesting that in T. gondii, PI(3)P-related function for the apicoplast might mainly be to serve as a precursor for the synthesis of PI(3,5)P2 . Accordingly, PI3K is conserved in all apicomplexan parasites whereas PIKfyve and ArPIKfyve are absent in Cryptosporidium species that lack an apicoplast, supporting a direct role of PI(3,5)P2 in apicoplast homeostasis. This study enriches the already diverse functions attributed to PI(3,5)P2 in eukaryotic cells and highlights these parasite lipid kinases as potential drug targets.

  19. Epidemiological study of Toxoplasma gondii infection in ovine breeding.

    PubMed

    Zedda, M T; Rolesu, S; Pau, S; Rosati, I; Ledda, S; Satta, G; Patta, C; Masala, G

    2010-12-01

    An outbreak of toxoplasmosis occurring in a typical farm of 524 ovines was monitored for 1 year after the occurrence of 31 abortions. Abortion events involved 7.2% of 430 pregnant sheep. Presence of antibodies to Toxoplasma gondii in sheep sera was investigated by the indirect fluorescence antibody test (IFAT). A total of 422 ewes were bled four times during the year, and an epidemiological analysis was performed on all serology data collected in this subgroup. The prevalence of IgG positives ranged from 31.52% (133/422) at the first sampling to 62.56% (264/422) at the fourth sampling. Incidence of IgG antibodies was 38.75% at the second sampling, 14.92% at the third and 29.28% at the fourth sampling. At the beginning of the study, prevalence was 70.7% in primiparous sheep and 20.9% in sheep older than 5 years; at the third sampling, prevalence was stable at 70% in pluriparous sheep. The mean prevalence of IgM antibodies was 14.87%. A total of 147 out of all 524 ovines of the flock tested positive for IgM in more than one sampling. After an initial positivity, 60 sheep tested negative for IgG at the following serological controls (4 between the first and the second sampling, 30 between the second and the third and 28 between the third and the fourth sampling). One stray cat was positive for IgG, with a titre of 1 : 320. Moreover, one of the farmers was also positive, with a titre of 1 : 160 for IgG. A positive PCR result for T. gondii DNA was also observed in aliquots of grain and pellets taken from feed stocks amassed inside the sheds without protection, suggesting that an adequate management of the farm might be useful, if not essential, for controlling T. gondii outbreaks in ovine flocks.

  20. Interferon-γ : The Major Mediator of Resistance against Toxoplasma gondii

    NASA Astrophysics Data System (ADS)

    Suzuki, Yasuhiro; Orellana, Manuel A.; Schreiber, Robert D.; Remington, Jack S.

    1988-04-01

    Mice were injected with a monoclonal antibody to interferon-γ to examine the importance of endogenous production of this lymphokine in resistance against infection with the sporozoan parasite Toxoplasma gondii. Mice with intraperitoneal infections of T. gondii that received no antibody survived and developed chronic T. gondii infection, whereas the infected mice that received the monoclonal antibody died of toxoplasmosis. The activation of macrophages, which kill T. gondii in vivo, was inhibited by administration of the monoclonal antibody, but the production of antibodies to T. gondii was not suppressed. The fact that an antibody to interferon-γ can eliminate resistance to acute Toxoplasma infection in mice suggests that this lymphokine is an important mediator of host resistance to this parasite.

  1. A Toxoplasma gondii Ortholog of Plasmodium GAMA Contributes to Parasite Attachment and Cell Invasion

    PubMed Central

    Carruthers, Vern B.

    2016-01-01

    ABSTRACT Toxoplasma gondii and its Plasmodium kin share a well-conserved invasion process, including sequential secretion of adhesive molecules for host cell attachment and invasion. However, only a few orthologs have been shown to be important for efficient invasion by both genera. Bioinformatic screening to uncover potential new players in invasion identified a previously unrecognized T. gondii ortholog of Plasmodium glycosylphosphatidylinositol-anchored micronemal antigen (TgGAMA). We show that TgGAMA localizes to the micronemes and is processed into several proteolytic products within the parasite prior to secretion onto the parasite surface during invasion. TgGAMA from parasite lysate bound to several different host cell types in vitro, suggesting a role in parasite attachment. Consistent with this function, tetracycline-regulatable TgGAMA and TgGAMA knockout strains showed significant reductions in host cell invasion at the attachment step, with no defects in any of the other stages of the parasite lytic cycle. Together, the results of this work reveal a new conserved component of the adhesive repertoire of apicomplexan parasites. IMPORTANCE Toxoplasma gondii is a successful human pathogen in the same phylum as malaria-causing Plasmodium parasites. Invasion of a host cell is an essential process that begins with secretion of adhesive proteins onto the parasite surface for attachment and subsequent penetration of the host cell. Conserved invasion proteins likely play roles that were maintained through the divergence of these parasites. Here, we identify a new conserved invasion protein called glycosylphosphatidylinositol-anchored micronemal antigen (GAMA). Tachyzoites lacking TgGAMA were partially impaired in parasite attachment and invasion of host cells, yielding the first genetic evidence of a specific role in parasite entry into host cells. These findings widen our appreciation of the repertoire of conserved proteins that apicomplexan parasites employ for

  2. Antibodies to Toxoplasma gondii in Patients With Schizophrenia: A Meta-Analysis

    PubMed Central

    Torrey, E. Fuller; Bartko, John J.; Lun, Zhao-Rong; Yolken, Robert H.

    2007-01-01

    Recent studies have linked infectious agents to schizophrenia. The largest number of studies has involved the analysis of Toxoplasma gondii; these studies were subjected to a meta-analysis. Published articles and abstracts were identified by searches of MEDLINE, Ovid, and Google Scholar; by a search of Chinese publications; through letters to researchers; and by visiting China. Published and unpublished controlled studies that used serological methods for measuring T. gondii antibodies to assess inpatients and/or outpatients diagnosed with schizophrenia were selected for analysis, and source documents were translated as needed. Forty-two studies carried out in 17 countries over 5 decades were identified; 23 of these (6 unpublished) met selection criteria. The combined odds ratio (OR) was 2.73 (95% confidence interval, 2.10 to 3.60; chi-square with 1 df 263; P < .000001). Seven studies that included only patients with first-episode schizophrenia (OR 2.54) did not differ significantly from 16 studies that included patients in all clinical phases (OR 2.79). The results suggest that individuals with schizophrenia have an increased prevalence of antibodies to T. gondii. This association is consistent with other epidemiological studies as well as with animal studies. Although the OR of 2.73 is modest, it exceeds that for genetic or other environmental factors identified to date and suggests that Toxoplasma is in some way associated with a large number of cases of schizophrenia. If an etiological association can be proven, it would have implications for the design of measures for the prevention and treatment of this disease. PMID:17085743

  3. Toxoplasma gondii isolates from mouflon sheep (Ovis ammon) from Hawaii, USA.

    PubMed

    Verma, Shiv K; Su, Chunlei; Dubey, Jitender P

    2015-01-01

    Little is known of Toxoplasma gondii isolates circulating in wildlife. The mouflon (Ovis ammon) is very popular game animal, hunted for its trophy horns. Here, we report the isolation and genetic characterization of T. gondii from two mouflons from Hawaii, USA. Both sheep had antibodies titers of 1:800 or higher. Viable T. gondii were isolated and nested PCR-RFLP genotyping revealed two genotypes, a clonal Type III (designated TgMouflonUS1), and a new genotype (designated TgMouflonUS2, and ToxoDB PCR-RFLP genotypes #249). This is the first report of T. gondii infection, isolation and genetic characterization in mouflons from the USA.

  4. GENETIC POLYMORPHISM OF TOXOPLASMA GONDII FROM RECENTLY INFECTED ABORTED EGYPTIAN WOMEN.

    PubMed

    Badr, Mohamed S; Attia, Samar S; El-Sherbiny, Walid S; Abd-Allah M A, El Ebidi; Hefny, Hesham M; Salem, Ahmed N M

    2016-04-01

    Toxoplasmosis caused by Toxoplasma gondii is one of the most prevalent parasitic diseases in human beings. Human toxoplasmosis can be associated with serious clinical manifestations, particularly in developing fetus. The aim of the current study was to identify the possible lineage type of Toxoplasma gondii, molecularly detected in placental samples of women whose pregnancies were spontaneously terminated in the first trimester. Preliminary detection of Toxoplasma genomic materials was done by a SYBR green qPCR technology. Subsequent identification of Toxoplasma strain was done for the positive samples using PCR-restriction fragment length polymorphism (RFLP) at the SAG2 loci of T. gondii using restriction enzymes HhaI and Sau3AI. Out of 72 tested samples, Toxoplasma B1 gene was detected in 9 cases. Toxoplasma genotypes I and II in addition to unknown type were identified in 4, 3 and 2 cases respectively, while type III was not detected in our samples, hence excluded as a leading cause of abortion in humans in our preliminary study. Nevertheless, it remains uncertain to what extent the genotype of the parasite directly contributes to the clinical severity of human toxoplasmosis. Certainly, advanced molecular techniques targeting different Toxoplasma strains are crucial for better understanding of human toxoplasmosis. For more elucidation, additional studies are recommended intended for genetic characterization of such serious parasitic infection using larger number of samples.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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. High prevalence of toxoplasmosis in cats from Egypt: isolation of viable Toxoplasma Gondii, tissue distribution, and isolate designation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cats are important in the epidemiology of Toxoplasma gondii because they are the only hosts that excrete environmentally resistant oocysts in feces. In the present study, 158 feral cats from Giza, Egypt were examined for T. gondii infection. Antibodies to T. gondii were found in 97.4% with modified ...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 ...

  10. Unique substrate specificity of ornithine aminotransferase from Toxoplasma gondii.

    PubMed

    Astegno, Alessandra; Maresi, Elena; Bertoldi, Mariarita; La Verde, Valentina; Paiardini, Alessandro; Dominici, Paola

    2017-03-07

    Toxoplasma gondii is a protozoan parasite of medical and veterinary relevance responsible for toxoplasmosis in humans. As an efficacious vaccine remains a challenge, chemotherapy is still the most effective way to combat the disease. In search of novel druggable targets, we performed a thorough characterization of the putative pyridoxal 5'-phosphate (PLP)-dependent enzyme ornithine aminotransferase from T. gondii ME49 (TgOAT). We overexpressed the protein in Escherichia coli and analysed its molecular and kinetic properties by UV-visible absorbance, fluorescence and CD spectroscopy, in addition to kinetic studies of both the steady state and pre-steady state. TgOAT is largely similar to OATs from other species regarding its general transamination mechanism and spectral properties of PLP; however, it does not show a specific ornithine aminotransferase activity like its human homologue, but exhibits both N-acetylornithine and γ-aminobutyric acid (GABA) transaminase activity in vitro, suggesting a role in both arginine and GABA metabolism in vivo The presence of Val79 in the active site of TgOAT in place of Tyr, as in its human counterpart, provides the necessary room to accommodate N-acetylornithine and GABA, resembling the active site arrangement of GABA transaminases. Moreover, mutation of Val79 to Tyr results in a change of substrate preference between GABA, N-acetylornithine and L-ornithine, suggesting a key role of Val79 in defining substrate specificity. The findings that TgOAT possesses parasite-specific structural features as well as differing substrate specificity from its human homologue make it an attractive target for anti-toxoplasmosis inhibitor design that can be exploited for chemotherapeutic intervention.

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

    PubMed

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

    2017-02-03

    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.

  12. Toxoplasma gondii infection reduces predator aversion in rats through epigenetic modulation in the host medial amygdala.

    PubMed

    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.

  13. Discovery of Potent and Selective Leads against Toxoplasma gondii Dihydrofolate Reductase via Structure-Based Design.

    PubMed

    Welsch, Matthew E; Zhou, Jian; Gao, Yueqiang; Yan, Yunqing; Porter, Gene; Agnihotri, Gautam; Li, Yingjie; Lu, Henry; Chen, Zhongguo; Thomas, Stephen B

    2016-12-08

    Current treatment of toxoplasmosis targets the parasite's folate metabolism through inhibition of dihydrofolate reductase (DHFR). The most widely used DHFR antagonist, pyrimethamine, was introduced over 60 years ago and is associated with toxicity that can be largely attributed to a similar affinity for parasite and human DHFR. Computational analysis of biochemical differences between Toxoplasma gondii and human DHFR enabled the design of inhibitors with both improved potency and selectivity. The approach described herein yielded TRC-19, a promising lead with an IC50 of 9 nM and 89-fold selectivity in favor of Toxoplasma gondii DHFR, as well as crystallographic data to substantiate in silico methodology. Overall, 50% of synthesized in silico designs met hit threshold criteria of IC50 < 10 μM and >2-fold selectivity favoring Toxoplasma gondii, further demonstrating the efficiency of our structure-based drug design approach.

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

    PubMed Central

    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. PMID:27882868

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

    PubMed

    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.

  16. Knockout of leucine aminopeptidase in Toxoplasma gondii using CRISPR/Cas9.

    PubMed

    Zheng, Jun; Jia, Honglin; Zheng, Yonghui

    2015-02-01

    Leucine aminopeptidases of the M17 peptidase family represent ideal drug targets for therapies directed against the pathogens Plasmodium, Babesia and Trypanosoma. Previously, we characterised Toxoplasma gondii leucine aminopeptidase and demonstrated its role in regulating the levels of free amino acids. In this study, we evaluated the potential of T. gondii leucine aminopeptidase as a drug target in T. gondii by a knockout method. Existing knockout methods for T. gondii have many drawbacks; therefore, we developed a new technique that takes advantage of the CRISPR/Cas9 system. We first chose a Cas9 target site in the gene encoding T. gondii leucine aminopeptidase and then constructed a knockout vector containing Cas9 and the single guide RNA. After transfection, single tachyzoites were cloned in 96-well plates by limiting dilution. Two transfected strains derived from a single clone were cultured in Vero cells, and then subjected to expression analysis by western blotting. The phenotypic analysis revealed that knockout of T. gondii leucine aminopeptidase resulted in inhibition of attachment/invasion and replication; both the growth and attachment/invasion capacity of knockout parasites were restored by complementation with a synonymously substituted allele of T. gondii leucine aminopeptidase. Mouse experiments demonstrated that T. gondii leucine aminopeptidase knockout somewhat reduced the pathogenicity of T. gondii. An enzymatic activity assay showed that T. gondii leucine aminopeptidase knockout reduced the processing of a leucine aminopeptidase-specific substrate in T. gondii. The absence of leucine aminopeptidase activity could be slightly compensated for in T. gondii. Overall, T. gondii leucine aminopeptidase knockout influenced the growth of T. gondii, but did not completely block parasite development, virulence or enzymatic activity. Therefore, we conclude that leucine aminopeptidase would be useful only as an adjunctive drug target in T. gondii.

  17. Parasiticidal activity of human alpha-defensin-5 against Toxoplasma gondii.

    PubMed

    Tanaka, Tetsuya; Rahman, Md Morshedur; Battur, Banzragch; Boldbaatar, Damdinsuren; Liao, Min; Umemiya-Shirafuji, Rika; Xuan, Xuenan; Fujisaki, Kozo

    2010-06-01

    Human defensins play a fundamental role in the initiation of innate immune responses to some microbial pathogens. In this paper, we show that human alpha-defensin-5 displays a parasiticidal role against Toxoplasma gondii, the causative agent of toxoplasmosis. Exposure of the tachyzoite form of T. gondii to defensin induced aggregation and significantly reduced parasite viability in a concentration-dependent peptide. Pre-incubation of tachyzoites with human alpha-defensin-5 followed by exposure to a mouse embryonal cell line (NIH/3T3) significantly reduced T. gondii infection in these cells. Thus, human alpha-defensin-5 is an innate immune molecule that causes severe toxocity to T. gondii and plays an important role in reducing cellular infection. This is the first report showing that human alpha-defensin-5 causes aggregation, leading to Toxoplasma destruction.

  18. A survey of Toxoplasma gondii and Neospora caninum infecting house mice from a hybrid zone.

    PubMed

    Hůrková-Hofmannová, L; Qablan, M A; Juránková, J; Modrý, D; Piálek, J

    2014-02-01

    Toxoplasma gondii and Neospora caninum are closely related coccidian parasites infecting a wide range of wild and domestic animals as intermediate hosts, and rodents serve as important reservoir hosts during the life cycles of these parasites. The present study is aimed at identifying T. gondii and N. caninum infection in 360 wild house mice (Mus musculus) collected across the Czech-German border, where 2 genetically distinct mouse subspecies meet and hybridize. Toxoplasma gondii or N. caninum DNA was detected in the brains of individual mice by PCR, but mixed infections were never observed. No significant differences in gender or trapping localities were found in the positive mice. The survey reveals a low frequency of T. gondii (0.6%) and N. caninum (3.6%) occurrence in the house mice population of the monitored part of the hybrid zone.

  19. Seroepidemiology of Toxoplasma gondii infection in a Mennonite community in Durango State, Mexico.

    PubMed

    Alvarado-Esquivel, C; Rojas-Rivera, A; Estrada-Martínez, S; Sifuentes-Álvarez, A; Liesenfeld, O; García-López, C R; Dubey, J P

    2010-10-01

    There is a lack of information concerning the epidemiology of Toxoplasma gondii infection in Mennonites (an ethnic group of Mexican citizens of German descent living in rural communities). The prevalence of anti- T. gondii immunoglobulin (Ig) G and IgM antibodies was examined in 152 Mennonites in Durango State, Mexico, using enzyme-linked immunoassays. In total, 46 (30.3%) of 152 participants (mean age 38.4 ± 15.5 yr) had IgG T. gondii antibodies; 5 (3.3%) also had IgM T. gondii antibodies. Toxoplasma gondii infection was significantly associated with the presence of cats at home (adjusted OR  =  3.93; 95% CI: 1.40-11.05), raising cattle (adjusted OR  =  3.88; 95% CI: 1.24-12.11), consumption of pigeon meat (adjusted OR  =  3.0; 95% CI: 1.36-6.63), and consumption of untreated water (adjusted OR  =  2.42; 95% CI: 1.09-5.40). This is the first report of seroprevalence and contributing factors for T. gondii infection in Mennonites and of an association of the consumption of pigeon meat with T. gondii infection. Results of this study should be useful in the design of optimal preventive measures against T. gondii infection.

  20. Toxoplasma Gondii Infection and Depression: A Case–Control Seroprevalence Study

    PubMed Central

    Alvarado-Esquivel, Cosme; Sánchez-Anguiano, Luis Francisco; Hernández-Tinoco, Jesús; Berumen-Segovia, Luis Omar; Torres-Prieto, Yazmin Elizabeth; Estrada-Martínez, Sergio; Pérez-Álamos, Alma Rosa; Ortiz-Jurado, María Nalleli; Molotla-de-León, Gabriel; Beristain-García, Isabel; Rábago-Sánchez, Elizabeth; Liesenfeld, Oliver

    2016-01-01

    We assessed the association of Toxoplasma gondii infection and depression in a sample of psychiatric patients and control subjects without depression. We performed an age- and gender-matched case–control study of 89 patients suffering from depression attended in a public psychiatric hospital in Durango City, Mexico and 356 control subjects without depression from the general population of the same city. Participants were tested for the presence of anti-Toxoplasma IgG and IgM antibodies using enzyme-linked immunoassays. Anti-T. gondii IgG antibodies were found in 11 (12.4%) of the 89 cases and in 22 (6.2%) of the 356 controls (OR = 2.14; 95% CI: 1.00–4.59; P = 0.04). Anti-T. gondii IgM antibodies were found in four (19%) of 21 anti-T. gondii IgG seropositive controls but not in 11 anti-T. gondii IgG seropositive cases (P = 0.27). Patients aged 30 years old and younger had a significantly higher seroprevalence of T. gondii infection than controls of the same age group (P = 0.001). Results of the present study suggest a potential association between T. gondii infection and depression. Furthers studies to confirm our results and to determine the epidemiology of T. gondii in young depressed patients should be conducted. PMID:27429790

  1. Toxoplasma Gondii Infection and Depression: A Case-Control Seroprevalence Study.

    PubMed

    Alvarado-Esquivel, Cosme; Sánchez-Anguiano, Luis Francisco; Hernández-Tinoco, Jesús; Berumen-Segovia, Luis Omar; Torres-Prieto, Yazmin Elizabeth; Estrada-Martínez, Sergio; Pérez-Álamos, Alma Rosa; Ortiz-Jurado, María Nalleli; Molotla-de-León, Gabriel; Beristain-García, Isabel; Rábago-Sánchez, Elizabeth; Liesenfeld, Oliver

    2016-06-24

    We assessed the association of Toxoplasma gondii infection and depression in a sample of psychiatric patients and control subjects without depression. We performed an age- and gender-matched case-control study of 89 patients suffering from depression attended in a public psychiatric hospital in Durango City, Mexico and 356 control subjects without depression from the general population of the same city. Participants were tested for the presence of anti-Toxoplasma IgG and IgM antibodies using enzyme-linked immunoassays. Anti-T. gondii IgG antibodies were found in 11 (12.4%) of the 89 cases and in 22 (6.2%) of the 356 controls (OR = 2.14; 95% CI: 1.00-4.59; P = 0.04). Anti-T. gondii IgM antibodies were found in four (19%) of 21 anti-T. gondii IgG seropositive controls but not in 11 anti-T. gondii IgG seropositive cases (P = 0.27). Patients aged 30 years old and younger had a significantly higher seroprevalence of T. gondii infection than controls of the same age group (P = 0.001). Results of the present study suggest a potential association between T. gondii infection and depression. Furthers studies to confirm our results and to determine the epidemiology of T. gondii in young depressed patients should be conducted.

  2. Influence of Toxoplasma Gondii Infection on Symptoms and Signs of Menopause

    PubMed Central

    Alvarado-Esquivel, Cosme; Sánchez-Anguiano, Luis Francisco; Hernández-Tinoco, Jesús; Calzada-Torres, Edwin Adiel; Estrada-Martínez, Sergio; Pérez-Álamos, Alma Rosa; Vaquera-Enriquez, Raquel; Díaz-Herrera, Arturo; Segura-Moreno, Raúl; de Lourdes Guerrero-Carbajal, María; Rentería-López, María Guadalupe; García, Isabel Beristain; Rábago-Sánchez, Elizabeth; Liesenfeld, Oliver

    2016-01-01

    Some symptoms of menopause have also been described in patients with toxoplasmosis. Whether Toxoplasma gondii (T. gondii) infection has any influence on clinical manifestations of menopause is yet unknown. We sought to determine whether T. gondii exposure is associated with symptoms and signs of menopause. We performed a cross-sectional study of women attending a public health center in Durango City, Mexico. Participants were examined for the presence of anti-Toxoplasma IgG and IgM antibodies using enzyme-linked immunoassays. A questionnaire including 47 symptoms and signs potentially associated with menopause was applied. Association of seroprevalence for T. gondii with clinical characteristics of women was assessed by bivariate and multivariate analyses. Bivariate analysis showed that bouts of rapid heartbeat, breast pain, electric shock sensation, dizziness, digestive problems, low back pain, and migraine were associated with seropositivity to either IgG anti-T. gondii alone or both IgG and IgM anti-T. gondii. Breast pain was the only variable that was found to be associated with IgG seropositivity to T. gondii by multivariate analysis: (OR = 2.84; 95% CI: 1.35–5.90; P = 0.005). Our results suggest that T. gondii exposure may influence on the clinical manifestations of menopause. Results deserve further research. PMID:27141314

  3. Influence of Toxoplasma Gondii Infection on Symptoms and Signs of Menopause.

    PubMed

    Alvarado-Esquivel, Cosme; Sánchez-Anguiano, Luis Francisco; Hernández-Tinoco, Jesús; Calzada-Torres, Edwin Adiel; Estrada-Martínez, Sergio; Pérez-Álamos, Alma Rosa; Vaquera-Enriquez, Raquel; Díaz-Herrera, Arturo; Segura-Moreno, Raúl; de Lourdes Guerrero-Carbajal, María; Rentería-López, María Guadalupe; García, Isabel Beristain; Rábago-Sánchez, Elizabeth; Liesenfeld, Oliver

    2016-03-01

    Some symptoms of menopause have also been described in patients with toxoplasmosis. Whether Toxoplasma gondii (T. gondii) infection has any influence on clinical manifestations of menopause is yet unknown. We sought to determine whether T. gondii exposure is associated with symptoms and signs of menopause. We performed a cross-sectional study of women attending a public health center in Durango City, Mexico. Participants were examined for the presence of anti-Toxoplasma IgG and IgM antibodies using enzyme-linked immunoassays. A questionnaire including 47 symptoms and signs potentially associated with menopause was applied. Association of seroprevalence for T. gondii with clinical characteristics of women was assessed by bivariate and multivariate analyses. Bivariate analysis showed that bouts of rapid heartbeat, breast pain, electric shock sensation, dizziness, digestive problems, low back pain, and migraine were associated with seropositivity to either IgG anti-T. gondii alone or both IgG and IgM anti-T. gondii. Breast pain was the only variable that was found to be associated with IgG seropositivity to T. gondii by multivariate analysis: (OR = 2.84; 95% CI: 1.35-5.90; P = 0.005). Our results suggest that T. gondii exposure may influence on the clinical manifestations of menopause. Results deserve further research.

  4. Genotyping of Toxoplasma gondii from Rats (Rattus rattus) in Riyadh, Saudi Arabia.

    PubMed

    Elamin, Maha H

    2014-06-01

    Toxoplasma 3 main clonal lineages are designated as type I, II, and III; however, atypical and mixed genotypes were also reported. This study was conducted for detection of Toxoplasma gondii genotypes in rats (Rattus rattus) in Riyadh region, Saudi Arabia. PCR test on T. gondii B1 gene was conducted on ELISA IgM positive samples for confirmation of the infection. However, genetic analysis of the SAG2 locus was performed to determine T. gondii genotypes using PCR-RFLP technique. PCR test on T. gondii B1gene showed that 22 (81.5%) out of the 27 ELISA IgM positive samples have T. gondii DNA. Genotypic analysis shows that, of the total 22 PCR positive samples, only 13 (59.1%) were of type II, 7 (31.8%) were of type III, and 2 (9.1%) were of an unknown genotype. It is obvious that the prevalence of both type II and III is high in rats. No reports have been available on T. gondii genotypes among rats in Riyadh region, and only little is known about its seroprevalence in rats. Future studies on T. gondii genotypes in rats using multi-locus markers is needed in Riyadh region, Saudi Arabia for better understanding of T. gondii pathogenesis and treatment in humans and animals.

  5. Transient Transfection and Expression in the Obligate Intracellular Parasite Toxoplasma gondii

    NASA Astrophysics Data System (ADS)

    Soldati, Dominique; Boothroyd, John C.

    1993-04-01

    Toxoplasma gondii is a protozoan pathogen that produces severe disease in humans and animals. This obligate intracellular parasite provides an excellent model for the study of how such pathogens are able to invade, survive, and replicate intracellularly. DNA encoding chloramphenicol acetyltransferase was introduced into T. gondii and transiently expressed with the use of three vectors based on different Toxoplasma genes. The ability to introduce genes and have them efficiently and faithfully expressed is an essential tool for understanding the structure-function relation of genes and their products.

  6. [The effect of clotrimazole on the pathogen of toxoplasmosis, Toxoplasma gondii].

    PubMed

    Werner, H; Piekarski, G

    1976-01-01

    By means of a toxoplasma infection in the mouse it was tested whether the antimycotic agent bis-phenyl-(2-chlorophenyl)-1-imidazolyl-methane (clotrimazol, Canesten¿) is also effective against the asexual stages of replication of T. gondii as they occur in man. Canesten did not influence the forms of the proliferative phase of replication of T. gondii (trophozoites, pseudocysts = tachyzoites) either in vivo in infected mice or in vitro in the tissue culture.

  7. A Unique Dual Activity Amino Acid Hydroxylase in Toxoplasma gondii

    PubMed Central

    Gaskell, Elizabeth A.; Smith, Judith E.; Pinney, John W.; Westhead, Dave R.; McConkey, Glenn A.

    2009-01-01

    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. PMID:19277211

  8. Host metabolism regulates growth and differentiation of Toxoplasma gondii

    PubMed Central

    Weilhammer, Dina R.; Iavarone, Anthony T.; Villegas, Eric N.; Brooks, George A.; Sinai, Anthony P.; Sha, William C.

    2012-01-01

    A critical step in the pathogenesis of Toxoplasma gondii is conversion from the fast-replicating tachyzoite form experienced during acute infection to the slow-replicating bradyzoite form that establishes long-lived tissue cysts during chronic infection. Bradyzoite cyst development exhibits a clear tissue tropism in vivo, yet conditions of the host cell environment that influence this tropism remain unclear. Using an in vitro assay of bradyzoite conversion, we have found that cell types differ dramatically in the ability to facilitate differentiation of tachyzoites into bradyzoites. Characterization of cell types that were either resistant or permissive for conversion revealed that resistant cell lines release low molecular weight metabolites that could support tachyzoite growth under metabolic stress conditions and thereby inhibit bradyzoite formation in permissive cells. Biochemical analysis revealed that the glycolytic metabolite lactate is an inhibitory component of supernatants from resistant cells. Furthermore, upregulation of glycolysis in permissive cells through the addition of glucose or by overexpression of the host kinase, Akt, was sufficient to convert cells from a permissive to a resistant phenotype. These results suggest that the metabolic state of the host cell may play a role in determining the predilection of the parasite to switch from the tachyzoite to bradyzoite form. PMID:22940576

  9. Experimental Models of Ocular Infection with Toxoplasma Gondii

    PubMed Central

    Dukaczewska, Agata; Tedesco, Roberto; Liesenfeld, Oliver

    2015-01-01

    Ocular toxoplasmosis is a vision-threatening disease and the major cause of posterior uveitis worldwide. In spite of the continuing global burden of ocular toxoplasmosis, many critical aspects of disease including the therapeutic approach to ocular toxoplasmosis are still under debate. To assist in addressing many aspects of the disease, numerous experimental models of ocular toxoplasmosis have been established. In this article, we present an overview on in vitro, ex vivo, and in vivo models of ocular toxoplasmosis available to date. Experimental studies on ocular toxoplasmosis have recently focused on mice. However, the majority of murine models established so far are based on intraperitoneal and intraocular infection with Toxoplasma gondii. We therefore also present results obtained in an in vivo model using peroral infection of C57BL/6 and NMRI mice that reflects the natural route of infection and mimics the disease course in humans. While advances have been made in ex vivo model systems or larger animals to investigate specific aspects of ocular toxoplasmosis, laboratory mice continue to be the experimental model of choice for the investigation of ocular toxoplasmosis. PMID:26716018

  10. Experimental Models of Ocular Infection with Toxoplasma Gondii.

    PubMed

    Dukaczewska, Agata; Tedesco, Roberto; Liesenfeld, Oliver

    2015-12-01

    Ocular toxoplasmosis is a vision-threatening disease and the major cause of posterior uveitis worldwide. In spite of the continuing global burden of ocular toxoplasmosis, many critical aspects of disease including the therapeutic approach to ocular toxoplasmosis are still under debate. To assist in addressing many aspects of the disease, numerous experimental models of ocular toxoplasmosis have been established. In this article, we present an overview on in vitro, ex vivo, and in vivo models of ocular toxoplasmosis available to date. Experimental studies on ocular toxoplasmosis have recently focused on mice. However, the majority of murine models established so far are based on intraperitoneal and intraocular infection with Toxoplasma gondii. We therefore also present results obtained in an in vivo model using peroral infection of C57BL/6 and NMRI mice that reflects the natural route of infection and mimics the disease course in humans. While advances have been made in ex vivo model systems or larger animals to investigate specific aspects of ocular toxoplasmosis, laboratory mice continue to be the experimental model of choice for the investigation of ocular toxoplasmosis.

  11. Cancer in the parasitic protozoans Trypanosoma brucei and Toxoplasma gondii

    PubMed Central

    Lun, Zhao-Rong; Lai, De-Hua; Wen, Yan-Zi; Zheng, Ling-Ling; Shen, Ji-Long; Yang, Ting-Bo; Zhou, Wen-Liang; Qu, Liang-Hu; Hide, Geoff; Ayala, Francisco J.

    2015-01-01

    Cancer is a general name for more than 100 malignant diseases. It is postulated that all cancers start from a single abnormal cell that grows out of control. Untreated cancers can cause serious consequences and deaths. Great progress has been made in cancer research that has significantly improved our knowledge and understanding of the nature and mechanisms of the disease, but the origins of cancer are far from being well understood due to the limitations of suitable model systems and to the complexities of the disease. In view of the fact that cancers are found in various species of vertebrates and other metazoa, here, we suggest that cancer also occurs in parasitic protozoans such as Trypanosoma brucei, a blood parasite, and Toxoplasma gondii, an obligate intracellular pathogen. Without treatment, these protozoan cancers may cause severe disease and death in mammals, including humans. The simpler genomes of these single-cell organisms, in combination with their complex life cycles and fascinating life cycle differentiation processes, may help us to better understand the origins of cancers and, in particular, leukemias. PMID:26195778

  12. Functional modifications of macrophage activity after sublethal irradiation. [Toxoplasma gondii

    SciTech Connect

    Swartz, R.P.

    1982-01-01

    The modifications of macrophage activity following sublethal irradiation, both in vivo and in vitro, were studied using spreading and C3b-receptor-mediated ingestion assays. Nonelicited peritoneal washout cells were examined for changes in activity and selected population characteristics. The cells from irradiated mice were from a resident peritoneal population and not immigrating cells. The macrophage population showed enhanced activity early with a refractory period (24-48) when the macrophages were unresponsive to stimulation by irradiated lymphocytes. The enhanced activity was inversely dose dependent on macrophage. The lymphocytes showed a regulatory function(s) on the time post irradiation at which they were examined. Early lymphocytes exhibited the ability to enhance the activity of normal macrophages while lymphocytes removed 24 hours post irradiation could suppress the activity of already activated macrophages. The effect(s) of the various lymphocyte populations were reproduced with cell-free supernatants which was indicative of the production of lymphokines. Separation on nylon wool columns indicated that the activity resided primarily in the T-cell population of lymphocytes. In vitro irradiation indicated that stimulation of the lymphocytes is macrophage dependent. Additional work indicated that sublethally irradiated macrophages did not inhibit replication of the coccidian protozoon Toxoplasma gondii although they did show increased phagocytosis. Examination of the serum from whole body irradiated mice showed the presence of a postirradiation substance which enhanced the phagocytosis of normal macrophages. It was not present in the serum of normal mice and was not endotoxin.

  13. Assessment of the Effects of Extremely Low Frequency Electromagnetic Fields on Toxoplasma gondii

    PubMed Central

    OZLEM-CALISKAN, Sercin; ERTABAKLAR, Hatice; BILGIN, Mehmet Dincer; ERTUG, Sema

    2016-01-01

    Background: The effects of extremely low frequency electromagnetic fields (ELF-EMF) on Toxoplasma gondii have not been explained yet. The aim of this study was to assess the possible effects of ELF-EMF on growth, survival time and viability of Toxoplasma gondii. In addition, the life span of Toxoplasma infected animals was investigated. Methods: Sixty adult male BALB/c mice were used for in vivo and in vivo experiments in Laboratory of Biopyhsics and Parasitology of Medical Faculty, Adnan Menderes University, Turkey, in 2010. During in vivo experiments, pulsed and continuous EMFs were applied for 5 d to the infected mice. During in vivo experiments, pulsed and continuous EMF was applied to the tachyzoites within peritoneal exudates for 8 h/d at 4 °C and the tachyzoites were then injected to mice. In both experiments, the number of T. gondii in peritoneal exudates was counted and T. gondii protein bands patterns were investigated with polyacrylamide gel electrophoresis and Western Blotting. Results: Pulsed and continuous EMF exposure reduced the number of T. gondii tachyzoites in comparison to controls. However, no statistically significant differences were observed at the patterns of protein bands among the samples. Conclusion: EMF exposure induces a decrease in the number of T. gondii. Further studies are required to understand the mechanism of EMF on intracellular parasites. PMID:28096849

  14. First isolation and genetic characterization of a Toxoplasma gondii strain from a symptomatic human case of congenital toxoplasmosis in Romania

    PubMed Central

    Costache, Carmen Anca; Colosi, Horaţiu Alexandru; Blaga, Ligia; Györke, Adriana; Paştiu, Anamaria Ioana; Colosi, Ioana Alina; Ajzenberg, Daniel

    2013-01-01

    Very limited data exists on the genetic diversity of Toxoplasma gondii from Eastern Europe. We present the first Romanian case of symptomatic congenital toxoplasmosis in which the T. gondii strain was isolated after inoculation in mice of a cerebrospinal fluid sample from a living neonate. The T. gondii strain was genotyped with 15 microsatellite markers distributed on 10 of the 14 chromosomes of T. gondii. The strain had a type II genotype. PMID:23537840

  15. Molecules to modeling: Toxoplasma gondii oocysts at the human–animal–environment interface

    PubMed Central

    VanWormer, Elizabeth; Fritz, Heather; Shapiro, Karen; Mazet, Jonna A.K.; Conrad, Patricia A.

    2013-01-01

    Environmental transmission of extremely resistant Toxoplasma gondii oocysts has resulted in infection of diverse species around the world, leading to severe disease and deaths in human and animal populations. This review explores T. gondii oocyst shedding, survival, and transmission, emphasizing the importance of linking laboratory and landscape from molecular characterization of oocysts to watershed-level models of oocyst loading and transport in terrestrial and aquatic systems. Building on discipline-specific studies, a One Health approach incorporating tools and perspectives from diverse fields and stakeholders has contributed to an advanced understanding of T. gondii and is addressing transmission at the rapidly changing human–animal–environment interface. PMID:23218130

  16. Epidemiological review of Toxoplasma gondii infection in humans and animals in Portugal.

    PubMed

    Lopes, A P; Dubey, J P; Dardé, M-L; Cardoso, L

    2014-11-01

    Toxoplasmosis is a worldwide zoonosis. However, data from Portugal are limited and a considerable part of the literature is in Portuguese. Currently, the rate of congenital infection in Portugal is unknown, and almost nothing is known of sequelae of congenital toxoplasmosis. There is no recent general population-based serological survey of Toxoplasma gondii in humans in Portugal. In addition, there is little information on genetic characteristics of T. gondii in animals and humans. In the present paper, we review prevalence, clinical spectrum and epidemiology of T. gondii in humans and animals in Portugal. This knowledge should be useful to biologists, public health workers, physicians and veterinarians.

  17. Seroprevalence of Toxoplasma gondii infection in domestic sheep in Liaoning Province, northeastern China.

    PubMed

    Yang, Na; Li, Hongkui; He, Jianbin; Mu, Mingyang; Yang, Shuhua

    2013-02-01

    There is a lack of information regarding the prevalence of Toxoplasma gondii infection in sheep from northeastern China. In the present study, serum samples from 566 domestic sheep were collected from Liaoning Province, northeastern China, to investigate the prevalence of T. gondii antibodies using an indirect hemagglutination antibody test. Twenty-five of 566 samples (4.4%) were seropositive at the cutoff of 1:64 serum dilution. No difference was found among 6 geographic regions (P > 0.05). This is the first report of T. gondii infection in sheep in Liaoning Province.

  18. Structures of Toxoplasma gondii Tachyzoites, Bradyzoites, and Sporozoites and Biology and Development of Tissue Cysts†

    PubMed Central

    Dubey, J. P.; Lindsay, D. S.; Speer, C. A.

    1998-01-01

    Infections by the protozoan parasite Toxoplasma gondii are widely prevalent worldwide in animals and humans. This paper reviews the life cycle; the structure of tachyzoites, bradyzoites, oocysts, sporocysts, sporozoites and enteroepithelial stages of T. gondii; and the mode of penetration of T. gondii. The review provides a detailed account of the biology of tissue cysts and bradyzoites including in vivo and in vitro development, methods of separation from host tissue, tissue cyst rupture, and relapse. The mechanism of in vivo and in vitro stage conversion from sporozoites to tachyzoites to bradyzoites and from bradyzoites to tachyzoites to bradyzoites is also discussed. PMID:9564564

  19. Toxoplasma gondii infection, from predation to schizophrenia: can animal behaviour help us understand human behaviour?

    PubMed

    Webster, Joanne P; Kaushik, Maya; Bristow, Greg C; McConkey, Glenn A

    2013-01-01

    We examine the role of the protozoan Toxoplasma gondii as a manipulatory parasite and question what role study of infections in its natural intermediate rodent hosts and other secondary hosts, including humans, may elucidate in terms of the epidemiology, evolution and clinical applications of infection. In particular, we focus on the potential association between T. gondii and schizophrenia. We introduce the novel term 'T. gondii-rat manipulation-schizophrenia model' and propose how future behavioural research on this model should be performed from a biological, clinical and ethically appropriate perspective.

  20. Tissue distribution and molecular characterization of chicken isolates of Toxoplasma gondii from Peru.

    PubMed

    Dubey, J P; Levy, M Z; Sreekumar, C; Kwok, O C H; Shen, S K; Dahl, E; Thulliez, P; Lehmann, T

    2004-10-01

    The prevalence of Toxoplasma gondii in free-ranging chickens is a good indicator of the prevalence of T. gondii oocysts in the soil because chickens feed from the ground. The prevalence of T. gondii antibodies in sera of 50 free-range chickens (Gallus domesticus) from Peru was 26% on the basis of the modified agglutination test (MAT). Hearts, pectoral muscles, and brains of seropositive (MAT > or =1:5) chickens were bioassayed individually in mice. Tissues from the remaining 37 seronegative chickens were pooled and fed to 2 T. gondii-free cats. Feces of cats were examined for oocysts; they did not shed oocysts. Toxoplasma gondii was isolated from the hearts of 10 seropositive chickens but not from their brains and pectoral muscles. Genotyping of these isolates using the SAG2 locus indicated that 7 isolates were type I and 3 were type III. Six of the 7 type-I isolates were avirulent for mice, which was unusual because type-I isolates are considered virulent for mice. The T. gondii isolates were from chickens from different properties that were at least 200 m apart. Thus, each isolate is likely to be different. This is the first report of isolation of T. gondii from chickens from Peru.

  1. Prevalence of Toxoplasma gondii in rats (Rattus norvegicus) in Grenada, West Indies.

    PubMed

    Dubey, J P; Bhaiyat, M I; Macpherson, C N L; de Allie, C; Chikweto, A; Kwok, O C H; Sharma, R N

    2006-10-01

    Cats are important in the natural epidemiology of Toxoplasma gondii, because they are the only hosts that can excrete environmentally resistant oocysts. Cats are infected with T. gondii via predation on infected birds and rodents. During 2005, 238 rats (Rattus norvegicus) were trapped in Grenada, West Indies, and their sera along with tissue samples from their hearts and brains were examined for T. gondii infection. Antibodies to T. gondii were assayed by the modified agglutination test (MAT, titer 1:40 or higher); only 2 (0.8%) of 238 rats were found to be infected. Brains and hearts of all rats were bioassayed in mice. Toxoplasma gondii was isolated from the brain and the heart of only 1 rat, which had a MAT titer of 1:320. All of 5 mice inoculated with the heart tissue, and the 5 mice inoculated with the brain tissue of the infected rat remained asymptomatic, even though tissue cysts were found in their brains. Genetically, the isolates of T. gondii from the heart and the brain were identical and had genotype III by using the SAG1, SAG2, SAG3, BTUB, and GRA6 gene markers. These data indicate that rats are not important in the natural history of T. gondii in Grenada.

  2. Toxoplasma gondii coinfection with diseases and parasites in wild rabbits in Scotland.

    PubMed

    Mason, Sam; Dubey, J P; Smith, Judith E; Boag, Brian

    2015-09-01

    In wild rabbits (Oryctolagus cuniculus) on an estate in Perthshire, central Scotland, the seroprevalence of Toxoplasma gondii was 18/548 (3·3%). The wild rabbit could be a T. gondii reservoir and it has potential value as a sentinel of T. gondii in environmental substrates. Toxoplasma gondii was associated with female sex (P < 0·001) and with relatively heavy infections by Eimeria stiedae (P = 0·036). It was not associated with the intensity of coccidial oocysts, the severity of myxomatosis caused by the virus Myxomatosis cuniculi, the intensity of roundworm eggs, the year or season, rabbit age or distance from farm buildings. Coinfections could have been affected by gestational down regulation of type 1 T helper cells. A sudden influx or release of T. gondii oocysts might have occurred. This is the first report of T. gondii in any wild herbivore in Scotland and also the first report of lapine T. gondii as a coinfection with E. stiedae, M. cuniculi and helminths.

  3. Seroprevalence of Toxoplasma gondii Infection among HIV/AIDS Patients in Eastern China.

    PubMed

    Shen, Guoqiang; Wang, Xiaoming; Sun, Hui; Gao, Yaying

    2016-02-01

    Toxoplasmosis, a neglected tropical disease caused by the protozoan parasite Toxoplasma gondii, occurs throughout the world. Human T. gondii infection is asymptomatic in 80% of the population; however, the infection is life-threatening and causes substantial neurologic damage in immunocompromised patients such as HIV-infected persons. The major purpose of this study was to investigate the seroprevalence of T. gondii infection in subjects infected with HIV/AIDS in eastern China. Our findings showed 9.7% prevalence of anti-T. gondii IgG antibody in HIV/AIDS patients, which was higher than in intravenous drug users (2.2%) and healthy controls (4.7%), while no significant difference was observed in the seroprevalence of anti-Toxoplasma IgM antibody among all participants (P>0.05). Among all HIV/AIDS patients, 15 men (7.7%) and 10 women (15.9%) were positive for anti-T. gondii IgG antibody; however, no significant difference was detected in the seroprevalence of anti-Toxoplasma IgG antibody between males and females. The frequency of anti-Toxoplasma IgG antibody was 8.0%, 13.2%, 5.5%, and 0% in patients with normal immune function (CD4(+) T-lymphocyte count ≥500 cells/ml), immunocompromised patients (cell count ≥200 and <500 cells/ml), severely immunocompromised patients (cell count ≥50 and <200 cells/ml), and advanced AIDS patients, respectively (cell count <50 cells/ml), while only 3 immunocompromised patients were positive for anti-T. gondii IgM antibody. The results indicate a high seroprevalence of T. gondii infection in HIV/AIDS patients in eastern China, and a preventive therapy for toxoplasmosis may be given to HIV/AIDS patients based on CD4(+) T lymphocyte count.

  4. Seroprevalence of Toxoplasma gondii infection in domestic rabbits in Durango State, Mexico.

    PubMed

    Alvarado-Esquivel, Cosme; Alvarado-Esquivel, Domingo; Villena, I; Dubey, J P

    2013-09-01

    There is a lack of information concerning the seroprevalence of Toxoplasma gondii infection in rabbits in northern Mexico. Through a cross sectional study, antibodies to T. gondii were determined in 429 domestic rabbits in Durango State, Mexico using the modified agglutination test. Rabbits were raised in 29 properties in 6 municipalities. Overall, antibodies to T. gondii were found in 70 (16.3%) of 429 rabbits, with titers of 1:25 in 42, 1:50 in 19, 1:100 in 5, 1:200 in 3, and 1:800 in 1. Seropositive rabbits were found in 21 (72.4%) of 29 properties, including 16 of 21 homes, 4 of 5 farms, and 1 of 3 pet shops. This is the first study of T. gondii infection in rabbits in Durango, Mexico. Results indicate that infected rabbits are a potential source of T. gondii infection in humans in Durango State.

  5. Inorganic nanoparticles kill Toxoplasma gondii via changes in redox status and mitochondrial membrane potential.

    PubMed

    Adeyemi, Oluyomi Stephen; Murata, Yuho; Sugi, Tatsuki; Kato, Kentaro

    2017-01-01

    This study evaluated the anti-Toxoplasma gondii potential of gold, silver, and platinum nanoparticles (NPs). Inorganic NPs (0.01-1,000 µg/mL) were screened for antiparasitic activity. The NPs caused >90% inhibition of T. gondii growth with EC50 values of ≤7, ≤1, and ≤100 µg/mL for gold, silver, and platinum NPs, respectively. The NPs showed no host cell cytotoxicity at the effective anti-T. gondii concentrations; the estimated selectivity index revealed a ≥20-fold activity toward the parasite versus the host cell. The anti-T. gondii activity of the NPs, which may be linked to redox signaling, affected the parasite mitochondrial membrane potential and parasite invasion, replication, recovery, and infectivity potential. Our results demonstrated the antiparasitic potential of NPs. The findings support the further exploration of NPs as a possible source of alternative and effective anti-T. gondii agents.

  6. Atypical Toxoplasma gondii genotype in feral cats from the Fernando de Noronha Island, northeastern Brazil.

    PubMed

    Melo, R P B; Almeida, J C; Lima, D C V; Pedrosa, C M; Magalhães, F J R; Alcântara, A M; Barros, L D; Vieira, R F C; Garcia, J L; Mota, R A

    2016-07-15

    Toxoplasma gondii isolates from Brazil have a different phenotypic and genotypic pattern, with predominance of virulent isolates and recombinant genotypes, compared to the North Hemisphere. Considering that a new T. gondii genotype, non-pathogenic to mice, was previously identified from free-range chickens from the Fernando de Noronha Island, Brazil, this study aimed to identify genotypes of this parasite in tissue samples of feral cats (Felis catus) from this Brazilian Island. Anti-T. gondii IgG antibodies were detected in 18/31 (58%) feral cats. Two non-virulent T. gondii isolates were obtained by mouse bioassay. Genotyping was performed by PCR-RFLP using 10 genetic markers (SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, PK1, L358 and Apico) and an atypical strain of T. gondii (ToxoDB #146) was identified. This is the first report of this genotype in feral cats.

  7. Toxoplasma gondii: uptake and survival of oocysts in free-living amoebae.

    PubMed

    Winiecka-Krusnell, Jadwiga; Dellacasa-Lindberg, Isabel; Dubey, J P; Barragan, Antonio

    2009-02-01

    Waterborne transmission of the oocyst stage of Toxoplasma gondii can cause outbreaks of clinical toxoplasmosis in humans and infection of marine mammals. In water-related environments and soil, free-living amoebae are considered potential carriers of various pathogens, but knowledge on interactions with parasitic protozoa remains elusive. In the present study, we assessed whether the free-living Acanthamoeba castellanii, due to its phagocytic activity, can interact with T. gondii oocysts. We report that amoebae can internalize T. gondii oocysts by active uptake. Intracellular oocysts in amoebae rarely underwent phagocytic lysis, retained viability and established infection in mice. Interaction of T. gondii with amoebae did not reduce the infectivity and pathogenicity of oocysts even after prolonged co-cultivation. Our results show that uptake of oocysts by A. castellanii does not restrain the transmission of T. gondii in a murine infection model.

  8. Effect of irradiation on the viability of Toxoplasma gondii cysts in tissues of mice and pigs

    SciTech Connect

    Dubey, J.P.; Brake, R.J.; Murrell, K.D.; Fayer, R.

    1986-03-01

    Muscles from tongue, heart, and limbs of 14 pigs inoculated orally with Toxoplasma gondii oocysts were irradiated with 10, 20, 25, and 30 krad of gamma (cesium-137 and cobalt-60) irradiation. Viability of T gondii cysts was assayed by feeding porcine muscles to T gondii-free cats and/or by inoculation of sediment from acid-pepsin digested porcine muscle into mice. Cats fed 500-g samples of muscles irradiated with up to 20 krad shed T gondii oocysts. Cats fed muscles irradiated with 25 or 30 krad did not shed oocysts. Mice were inoculated with 8 isolates of T gondii, and tissue cysts in their brains irradiated with up to 40 krad were infective to mice; however, there was a 10,000-fold reduction in the viability of organisms in tissue cysts irradiated with 40 krad, compared with that in nonirradiated cysts. At 50 krad of gamma irradiation, there were no detectable infective organisms in infected mouse brains.

  9. Inorganic nanoparticles kill Toxoplasma gondii via changes in redox status and mitochondrial membrane potential

    PubMed Central

    Adeyemi, Oluyomi Stephen; Murata, Yuho; Sugi, Tatsuki; Kato, Kentaro

    2017-01-01

    This study evaluated the anti-Toxoplasma gondii potential of gold, silver, and platinum nanoparticles (NPs). Inorganic NPs (0.01–1,000 µg/mL) were screened for antiparasitic activity. The NPs caused >90% inhibition of T. gondii growth with EC50 values of ≤7, ≤1, and ≤100 µg/mL for gold, silver, and platinum NPs, respectively. The NPs showed no host cell cytotoxicity at the effective anti-T. gondii concentrations; the estimated selectivity index revealed a ≥20-fold activity toward the parasite versus the host cell. The anti-T. gondii activity of the NPs, which may be linked to redox signaling, affected the parasite mitochondrial membrane potential and parasite invasion, replication, recovery, and infectivity potential. Our results demonstrated the antiparasitic potential of NPs. The findings support the further exploration of NPs as a possible source of alternative and effective anti-T. gondii agents. PMID:28280332

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

    PubMed Central

    2014-01-01

    Background 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. Methods 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. Results 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. Conclusions 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

  11. Seroprevalence of and Risk Factors for Toxoplasma gondii Infection in Cats in Estonia.

    PubMed

    Must, Kärt; Lassen, Brian; Jokelainen, Pikka

    2015-10-01

    In Estonia, northeastern Europe, Toxoplasma gondii seroprevalence in humans has not declined, in contrast to many other countries. The reasons for this are unknown. Domestic cats are important hosts in the epidemiology of the parasite, but information on local feline T. gondii infections has been lacking. An epidemiological cross-sectional study was conducted to estimate the seroprevalence of T. gondii and the risk factors associated with seropositivity in cats in Estonia. Surplus from blood samples that had been collected for unrelated diagnostic purposes from 306 pet cats and 184 shelter cats were analyzed for anti-T. gondii immunoglobulin G antibodies by using a direct agglutination test. Two questionnaires were designed to reveal relevant risk factors for seropositivity. The overall seroprevalence of T. gondii in cats in Estonia was 60.8%. Older age, outdoor access, hunting, living outside the city in the countryside, and not being a purebred cat were among the risk factors associated with seropositivity. T. gondii is highly prevalent in domestic cats in Estonia. This suggests that the environment has been contaminated with T. gondii. Seropositivity indicates previous oocyst shedding, and most of the cats had outdoor access. The increase in T. gondii seroprevalence with age indicates acquired infections, and most of the risk factors were lifestyle-related. Cat owners could diminish the risk of T. gondii infection and also limit the spread of the parasite by not allowing their cats to roam free.

  12. 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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  13. Uptake and transmission of Toxoplasma gondii oocysts by migratory filter-feeding fish

    EPA Science Inventory

    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...

  14. Prevalence and risk factors of Toxoplasma gondii infection in meat products destined for human consumption

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Toxoplasma gondii is a protozoan parasite that is responsible for approximately 24% of all estimated deaths attributed to foodborne pathogens in the U.S. Human infection results from accidental ingestion of oocysts, from the environment, in water or on insufficiently washed produce or through consum...

  15. NextGen sequencing reveals short double crossovers contribute disproportionately to genetic diversity in Toxoplasma gondii

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Toxoplasma gondii is a widespread protozoan parasite of animals that causes zoonotic disease in humans. Three clonal variants predominate in North America and Europe, while South American strains are genetically diverse, and undergo more frequent recombination. All three northern clonal variants s...

  16. Seroprevalence of Toxoplasma gondii among turkeys on family farms in the state of Northeastern Brazil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  17. Serological evidence of Toxoplasma gondii infection in wild birds and mammals from Southeast region of Brazil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In this study, serum samples of 53 wild animals from two different states from the southeast region of Brazil were analyzed for the presence of anti-Toxoplasma gondii antibodies by the modified agglutination test (MAT) with a cut off of 1:5 for birds and 1:25 for mammals. Out of the sampled animals,...

  18. Seroprevalence of Toxoplasma gondii antibodies in captive wild mammals and birds in Brazil.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In this study serum samples of 203 animals from different locations from zoos and breeding facilities from the north and northeast region of Brazil were analyzed for the presence of anti-Toxoplasma gondii antibodies by the modified agglutination test (MAT) with a cutoff of 1:25. Of the sampled anima...

  19. Toxoplasma gondii in horse meat intended for human consumption in Romania

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The prevalence of Toxoplasma gondii, an economically important zoonotic protozoan, was investigated in horses slaughtered for export and human consumption in the North of Romania. This study has aimed to assess the potential impact of Romanian horses’ toxoplasmosis on the public health. Pairs of sam...

  20. Patterns of Hydrocephalus Caused by Congenital Toxoplasma gondii Infection Associate With Parasite Genetics

    PubMed Central

    Hutson, Samuel L.; Wheeler, Kelsey M.; McLone, David; Frim, David; Penn, Richard; Swisher, Charles N.; Heydemann, Peter T.; Boyer, Kenneth M.; Noble, A. Gwendolyn; Rabiah, Peter; Withers, Shawn; Montoya, Jose G.; Wroblewski, Kristen; Karrison, Theodore; Grigg, Michael E.; McLeod, Rima

    2015-01-01

    Four anatomical patterns of hydrocephalus secondary to congenital Toxoplasma gondii infection were identified and characterized for infants enrolled in the National Collaborative Chicago-based Congenital Toxoplasmosis Study. Analysis of parasite serotype revealed that different anatomical patterns associate with Type-II vs Not-Exclusively Type-II strains (NE-II) (P = .035). PMID:26405147

  1. Isolation and genotyping of Toxoplasma gondii from Ugandan chickens reveals frequent multiple infections

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The genetic makeup of an infecting Toxoplasma gondii strain may be important for the outcome of infection and the risk of reactivation of chronic disease. In order to survey the distribution of different genotypes within an area, free-range chickens act as a good model species. In this study 85 chic...

  2. PREVALENCE OF ANTIBODIES AGAINST TOXOPLASMA GONDII IN POLAR BEARS (URSUS MARITIMUS) FROM SVALBARD AND EAST GREENLAND

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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. Genotyping of Toxoplasma gondii isolates with 15 microsatellite markers in a single multiplex PCR assay.

    PubMed

    Ajzenberg, Daniel; Collinet, Frédéric; Mercier, Aurélien; Vignoles, Philippe; Dardé, Marie-Laure

    2010-12-01

    We developed an easy-to-use method for genotyping Toxoplasma gondii isolates in a single multiplex PCR assay with 15 microsatellite markers. This method was validated by testing 26 reference isolates that had been characterized with other sets of markers.

  4. Host mitochondrial association evolved in the human parasite Toxoplasma gondii via neofunctionalization of a gene duplicate

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In Toxoplasma gondii, an intracellular parasite of humans and other warm-blooded animals, the ability to associate with host mitochondria (HMA) is driven by a locally expanded gene family that encodes multiple mitochondrial association factor 1 (MAF1) proteins. The importance of copy number in the e...

  5. Risk factors associated with Toxoplasma gondii infection in captive Sapajus spp

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The aim of this study was to identify risk factors associated with prevalence of Toxoplasma gondii infection in captive capuchin monkeys at a facility in the northeastern Brazil. Serum samples from 116 bearded capuchin (Sapajus libidinosus), nine blonde capuchin (Sapajus flavius), five black-capped ...

  6. Toxoplasma gondii in feral american minks at the Maullin river, Chile

    Technology Transfer Automated Retrieval System (TEKTRAN)

    American mink (Neovison vison) is a widely distributed invasive species in southern Chile. Thirty four feral minks were trapped at two distinct sites (rural and peri-urban), diet analyzed, and Toxoplasma gondii exposure compared using PCR and specific antibodies. Serum samples were evaluated using a...

  7. History of the discovery of the life cycle of Toxoplasma gondii

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 ...

  8. SEROLOGICAL SURVEY OF ANTIBODIES TO TOXOPLASMA GONDII IN SHEEP, CATTLE, AND BUFFALOES IN PUNJAB, INDIA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sera from 186 sheep, 83 cattle, and 103 water buffaloes from Punjab, India were evaluated for antibodies to Toxoplasma gondii using a commercial ELISA kit. This study was planned using a 2-stage random sampling procedure employing sampling software ‘survey toolbox’. In the first step, villages were...

  9. Detection of zoonotic protozoa Toxoplasma gondii and Sarcocystis suihominis in wild boars from Spain

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Food safety regulations require the control of presence of protozoa in meats destined for human consumption. Wild boar (Sus scrofa) meat may constitute a source of zoonoses. A 23.8% (688/2881) seroprevalence of anti-Toxoplasma gondii antibodies, and 72.2% (662/910) Sarcocystis sarcocysts prevalence ...

  10. Association of Ocular Toxoplasmosis with Type I Toxoplasma gondii Strains: Direct Genotyping from Peripheral Blood Samples▿

    PubMed Central

    Switaj, Karolina; Master, Adam; Borkowski, Piotr Karol; Skrzypczak, Magdalena; Wojciechowicz, Jacek; Zaborowski, Piotr

    2006-01-01

    Toxoplasma gondii strains were genotyped directly from blood samples of patients with ocular toxoplasmosis. Analysis of nontranscribed spacer 2 revealed that all detected strains belonged to type I, suggesting an association of ocular toxoplasmosis with this type. The method shows the usefulness of blood samples for genotyping in ocular toxoplasmosis. PMID:17005742

  11. Kennel dogs as sentinels of Leishmania infantum, Toxoplasma gondii and Neospora caninum in Majorca Island, Spain

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  12. Seroprevalence of Toxoplasma gondii in American Black Bears ( Ursus americanus ) of the Central Appalachians, USA.

    PubMed

    Cox, John J; Murphy, Sean M; Augustine, Ben C; Guthrie, Joseph M; Hast, John T; Maehr, Sutton C; McDermott, Joseph

    2017-03-20

    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. Red foxes (Vulpes vulpes) in Romania are carriers of Toxoplasma gondii but not Neospora caninum.

    PubMed

    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.

  14. Seroepidemiology of Toxoplasma gondii infection in women from the North of Portugal in their childbearing years

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  15. Prevalence of antibodies to Toxoplasma gondii in dogs from northeastern Portugal

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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%...

  16. Toxoplasma gondii prevalence in farm animals in the U.S.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Toxoplasmosis, caused by Toxoplasma gondii, is one of the most common parasitic infections of humans and other warmblooded animals. It has been found worldwide, and nearly one third of humans have been exposed to the parasite. Congenital infection occurs when a woman becomes infected during pregna...

  17. TOXOPLASMA GONDII : UPTAKE AND SURVIVAL OF OOCYSTS IN FREE-LIVING AMOEBAE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Waterborne transmission of the oocyst stage of Toxoplasma gondii can cause outbreaks of clinical toxoplasmosis in humans and infection of marine mammals. In water-related environments and soil, free-living amoebae are considered potential carriers of various pathogens, but knowledge on interactions ...

  18. Activity of pentamidine and pentamidine analogs against Toxoplasma gondii in cell cultures.

    PubMed Central

    Lindsay, D S; Blagburn, B L; Hall, J E; Tidwell, R R

    1991-01-01

    The capabilities of pentamidine and nine pentamidine analogs to inhibit the development of Toxoplasma gondii were examined in vitro. Treatment of infected cultures with pentamidine and five of its analogs caused a significant (P less than 0.05) reduction in the numbers of tachyzoites produced. Analogs of pentamidine may be useful agents in the treatment of toxoplasmosis. PMID:1952867

  19. Prevalence of antibodies to Leishmania infantum and Toxoplasma gondii in horses from the north of Portugal

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 (...

  20. Macrophages facilitate the excystation and differentiation of Toxoplasma gondii sporozoites into tachyzoites following oocyst internalization

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  1. High prevalance of Toxoplasma Gondii antibodies in domestic pigs in Oaxaca State, Mexico

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  2. Serology and genetics of Toxoplasma gondii in endangered Hawaiian (Nene) geese (Branta sandvicensis)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Toxoplasma gondii is parasite transmitted by feral cats that has historically caused mortality in native Hawaiian birds. A recent study revealed that this parasite accounts for ca. 4% of causes of mortality in native Hawaiian geese (nene-Branta sandvicensis). To know how widespread exposure to the...

  3. Transmission of Toxoplasma gondii - from land to sea: a personal perspective

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 ...

  4. Serological Evidence of Toxoplasma gondii infection in five species of bats in China

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  5. Characterization of Toxoplasma gondii isolates in free-range chickens from Argentina.

    PubMed

    Dubey, J P; Marcet, Paula L; Lehmann, T

    2005-12-01

    The prevalence of Toxoplasma gondii in free-ranging chickens is a good indicator of the prevalence of T. gondii oocysts in the soil because chickens feed from the ground. The prevalence of T. gondii in 61 free-range chickens (Gallus domesticus) from provinces of Santiago del Estero and Entre Rios, Argentina was determined. Antibodies to T. gondii were assayed by the modified agglutination test (MAT) and were found in 25 chickens; titers were 1:5 in 6 chickens, 1:10 in 1 chicken, 1:20 in 2 chickens, 1:40 in 1 chicken, 1:80 in 2 chickens, 1:60 in 4 chickens, 1:120 in 2 chickens, 1:640 in 3 chickens, and 1: 1,280 or higher in 4 chickens. Hearts, pectoral muscles, and brains of 22 seropositive (MAT 1:10 or higher) chickens were bioassayed individually in mice. Tissue from 39 chickens with titers of 1:5 or less were pooled and fed to 3 T. gondii-free cats. Feces of cats were examined for oocysts, but none was found. Toxoplasma gondii was isolated from 17 of 22 chickens with MAT titers of 1:10 or higher. Genotyping of these 17 isolates using polymorphisms at the SAG2 locus indicated that 4 were Type I, 3 were Type II, and 10 were Type III. Toxoplasma gondii isolates (2 Type I and I Type III) from 3 chickens were virulent for mice and 1 Type I was not mouse virulent. Prevalence of T. gondii antibodies in chickens varied among regions, being 3 times greater in the humid Pampeana region (61.2%) than in the semiarid plain of Santiago del Estero (20%).

  6. Epigenomic Modifications Predict Active Promoters and Gene Structure in Toxoplasma gondii

    PubMed Central

    Gissot, Mathieu; Kelly, Krystyna A; Ajioka, James W; Greally, John M; Kim, Kami

    2007-01-01

    Mechanisms of gene regulation are poorly understood in Apicomplexa, a phylum that encompasses deadly human pathogens like Plasmodium and Toxoplasma. Initial studies suggest that epigenetic phenomena, including histone modifications and chromatin remodeling, have a profound effect upon gene expression and expression of virulence traits. Using the model organism Toxoplasma gondii, we characterized the epigenetic organization and transcription patterns of a contiguous 1% of the T. gondii genome using custom oligonucleotide microarrays. We show that methylation and acetylation of histones H3 and H4 are landmarks of active promoters in T. gondii that allow us to deduce the position and directionality of gene promoters with >95% accuracy. These histone methylation and acetylation “activation” marks are strongly associated with gene expression. We also demonstrate that the pattern of histone H3 arginine methylation distinguishes certain promoters, illustrating the complexity of the histone modification machinery in Toxoplasma. By integrating epigenetic data, gene prediction analysis, and gene expression data from the tachyzoite stage, we illustrate feasibility of creating an epigenomic map of T. gondii tachyzoite gene expression. Further, we illustrate the utility of the epigenomic map to empirically and biologically annotate the genome and show that this approach enables identification of previously unknown genes. Thus, our epigenomics approach provides novel insights into regulation of gene expression in the Apicomplexa. In addition, with its compact genome, genetic tractability, and discrete life cycle stages, T. gondii provides an important new model to study the evolutionarily conserved components of the histone code. PMID:17559302

  7. Portugal and Angola: similarities and differences in Toxoplasma gondii seroprevalence and risk factors in pregnant women.

    PubMed

    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 seropositivity and cognitive functions in school-aged children.

    PubMed

    Mendy, A; Vieira, E R; Albatineh, A N; Gasana, J

    2015-08-01

    Toxoplasma gondii (T. gondii) infects one-third of the world population, but its association with cognitive functions in school-aged children is unclear. We examined the relationship between Toxoplasma seropositivity and neuropsychological tests scores (including math, reading, visuospatial reasoning and verbal memory) in 1755 school-aged children 12-16 years old who participated to the Third National Health and Nutrition Examination Survey, using multiple linear regressions adjusted for covariates. Toxoplasma seroprevalence was 7·7% and seropositivity to the parasite was associated with lower reading skills (regression coefficient [β] = -5·86, 95% confidence interval [CI]: -11·11, -0·61, P = 0·029) and memory capacities (β = -0·86, 95% CI: -1·58, -0·15, P = 0·017). The interaction between T. gondii seropositivity and vitamin E significantly correlated with memory scores. In subgroup analysis, Toxoplasma-associated memory impairment was worse in children with lower serum vitamin E concentrations (β = -1·61, 95% CI: -2·44, -0·77, P < 0·001) than in those with higher values (β = -0·12, 95% CI: -1·23, 0·99, P = 0·83). In conclusion, Toxoplasma seropositivity may be associated with reading and memory impairments in school-aged children. Serum vitamin E seems to modify the relationship between the parasitic infection and memory deficiency.

  9. Association Between Toxoplasma gondii Exposure and Heart Disease: A Case-Control Study

    PubMed Central

    Alvarado-Esquivel, Cosme; Salcedo-Jaquez, Misael; Sanchez-Anguiano, Luis Francisco; Hernandez-Tinoco, Jesus; Rabago-Sanchez, Elizabeth; Beristain-Garcia, Isabel; Liesenfeld, Oliver; Estrada-Martinez, Sergio; Perez-Alamos, Alma Rosa; Alvarado-Soto, Ediyair

    2016-01-01

    Background The parasite Toxoplasma gondii causes infections all around the world. Infections with T. gondii are systemic and the parasite can persist in the heart muscle. Very little is known about the impact of T. gondii on patients with heart disease. We determined the association between T. gondii exposure and patients suffering from heart diseases attending in a public hospital in Durango, Mexico; the association of T. gondii exposure with socio-demographic, behavioral, and clinical characteristics of these patients was also investigated. Methods Through a case-control study, we examined the seroprevalence of anti-T. gondii IgG and IgM antibodies in 400 patients with heart diseases and 400 age- and gender-matched controls using enzyme-linked immunoassays. In addition, we analyzed the association of patient characteristics as determined by a standardized questionnaire with T. gondii exposure by bivariate and multivariate analyses. Results Fifty-five (13.8%) of 400 patients and 32 (8.0%) of 400 controls had anti-T. gondii IgG antibodies (odds ratio (OR) = 1.83; 95% confidence interval (CI): 1.15 - 2.90; P = 0.01). High anti-T. gondii IgG levels (> 150 IU/mL) were found in 28 (50.9%) of the 55 positive cases and in 14 (43.8%) of the 32 positive controls (P = 0.51). Anti-T. gondii IgM antibodies were found in 13 (23.6%) of the 55 anti-T. gondii IgG positive patients and in 19 (59.4%) of 32 anti-T. gondii IgG positive controls (OR = 0.21; 95% CI: 0.08 - 0.54; P = 0.0008). Multivariate analysis showed that T. gondii exposure was positively associated with being born out of Durango State (OR = 2.93; 95% CI: 1.40 - 6.13; P = 0.004), and with consumption of alcohol (OR = 2.04; 95% CI: 1.01 - 4.12; P = 0.04). Conclusions Results obtained in this study indicate that T. gondii infection is associated with heart disease, and suggest that heart disease might be related with a chronic infection. This is the first report of an association of T. gondii exposure with alcohol

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

    PubMed Central

    Alvarado-Esquivel, Cosme; Sifuentes-Álvarez, Antonio; Narro-Duarte, Sergio Guadalupe; Estrada-Martínez, Sergio; Díaz-García, Juan Humberto; Liesenfeld, Oliver; Martínez-García, Sergio Arturo; Canales-Molina, Arturo

    2006-01-01

    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. PMID:16839423

  11. Using Quantitative Reverse Transcriptase PCR and Cell Culture Plaque Assays to Determine Resistance of Toxoplasma gondii Oocysts to Chemical Sanitizers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Toxoplasma gondii oocysts are highly resistant to many chemical sanitizers. Current methods used to determine oocyst infectivity have relied exclusively on mouse, chicken, and feline bioassays. Although considered gold standards, they only provide a qualitative assessment of oocyst infectivity. I...

  12. RNA Extraction Methods for Reverse Transcriptase Real-Time PCR and Microarray Analysis of Cryptosporidium and Toxoplasma gondii Oocysts

    EPA Science Inventory

    The ability of infectious oocyst forms of Toxoplasma gondii and Cryptosporidium spp. to resist disinfection treatments and cause disease may have significant public health implications. Currently, little is known about oocyst-specific factors involved during host cell invasion p...

  13. RNA Extraction Methods for Real-Time PCR and Microarray Analyses of Cryptosporidium and Toxoplasma gondii Oocysts - 2nd Presentation

    EPA Science Inventory

    The ability of infectious oocyst forms of Toxoplasma gondii and Cryptosporidium spp. to resist disinfection treatments and cause disease may have significant public health implications. Currently, little is known about oocyst-specific factors involved during host cell invasion pr...

  14. Evaluation of Four RNA Extraction Methods for Gene Expression Analyses of Cryptosporidium parvum and Toxoplasma gondii Oocys

    EPA Science Inventory

    Cryptosporidium spp. and Toxoplasma gondii are important coccidian parasites that have caused waterborne and foodborne disease outbreaks worldwide. Techniques like subtractive hybridization, microarrays, and quantitative reverse transcriptase real-time polymerase chain reaction (...

  15. Drinking water source and human Toxoplasma gondii infection in the United States: A cross-sectional analysis of NHANES data

    EPA Science Inventory

    Toxoplasma gondii imparts a considerable burden to public health. Human toxoplasmosis can be life-threatening in immunocompromised individuals, has been associated with psychiatric disorders, and can cause severe congenital pathologies, spontaneous abortion, or stillbirth. Enviro...

  16. Chronic Toxoplasma gondii in Nurr1-Null Heterozygous Mice Exacerbates Elevated Open Field Activity

    PubMed Central

    Eells, Jeffrey B.; Varela-Stokes, Andrea; Guo-Ross, Shirley X.; Kummari, Evangel; Smith, Holly M.; Cox, Erin; Lindsay, David S.

    2015-01-01

    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. PMID:25855987

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

    PubMed

    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.

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

    PubMed

    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.

  19. Evidence of the three main clonal Toxoplasma gondii lineages from wild mammalian carnivores in the UK.

    PubMed

    Burrells, A; Bartley, P M; Zimmer, I A; Roy, S; Kitchener, A C; Meredith, A; Wright, S E; Innes, E A; Katzer, F

    2013-12-01

    Toxoplasma gondii is a zoonotic pathogen defined by three main clonal lineages (types I, II, III), of which type II is most common in Europe. Very few data exist on the prevalence and genotypes of T. gondii in the UK. Wildlife can act as sentinel species for T. gondii genotypes present in the environment, which may subsequently be transmitted to livestock and humans. DNA was extracted from tissue samples of wild British carnivores, including 99 ferrets, 83 red foxes, 70 polecats, 65 mink, 64 badgers and 9 stoats. Parasite DNA was detected using a nested ITS1 PCR specific for T. gondii, PCR positive samples were subsequently genotyped using five PCR-RFLP markers. Toxoplasma gondii DNA was detected within all these mammal species and prevalence varied from 6·0 to 44·4% depending on the host. PCR-RFLP genotyping identified type II as the predominant lineage, but type III and type I alleles were also identified. No atypical or mixed genotypes were identified within these animals. This study demonstrates the presence of alleles for all three clonal lineages with potential for transmission to cats and livestock. This is the first DNA-based study of T. gondii prevalence and genotypes across a broad range of wild British carnivores.

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

    PubMed

    Rocchigiani, Guido; Nardoni, Simona; D'Ascenzi, Carlo; Nicoloso, Sandro; Picciolli, Federico; Papini, Roberto A; Mancianti, Francesca

    2016-12-01

    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 T. gondii 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.

  1. Toxoplasma gondii Superinfection and Virulence during Secondary Infection Correlate with the Exact ROP5/ROP18 Allelic Combination

    PubMed Central

    Jensen, Kirk D. C.; Camejo, Ana; Melo, Mariane B.; Cordeiro, Cynthia; Julien, Lindsay; Grotenbreg, Gijsbert M.; Frickel, Eva-Maria; Ploegh, Hidde L.; Young, Lucy

    2015-01-01

    ABSTRACT The intracellular parasite Toxoplasma gondii infects a wide variety of vertebrate species globally. Infection in most hosts causes a lifelong chronic infection and generates immunological memory responses that protect the host against new infections. In regions where the organism is endemic, multiple exposures to T. gondii likely occur with great frequency, yet little is known about the interaction between a chronically infected host and the parasite strains from these areas. A widely used model to explore secondary infection entails challenge of chronically infected or vaccinated mice with the highly virulent type I RH strain. Here, we show that although vaccinated or chronically infected C57BL/6 mice are protected against the type I RH strain, they are not protected against challenge with most strains prevalent in South America or another type I strain, GT1. Genetic and genomic analyses implicated the parasite-secreted rhoptry effectors ROP5 and ROP18, which antagonize the host’s gamma interferon-induced immunity-regulated GTPases (IRGs), as primary requirements for virulence during secondary infection. ROP5 and ROP18 promoted parasite superinfection in the brains of challenged survivors. We hypothesize that superinfection may be an important mechanism to generate T. gondii strain diversity, simply because two parasite strains would be present in a single meal consumed by the feline definitive host. Superinfection may drive the genetic diversity of Toxoplasma strains in South America, where most isolates are IRG resistant, compared to North America, where most strains are IRG susceptible and are derived from a few clonal lineages. In summary, ROP5 and ROP18 promote Toxoplasma virulence during reinfection. PMID:25714710

  2. Transmission of Toxoplasma: clues from the study of sea otters as sentinels of Toxoplasma gondii flow into the marine environment.

    PubMed

    Conrad, P A; Miller, M A; Kreuder, C; James, E R; Mazet, J; Dabritz, H; Jessup, D A; Gulland, Frances; Grigg, M E

    2005-10-01

    Toxoplasma gondii affects a wide variety of hosts including threatened southern sea otters (Enhydra lutris nereis) which serve as sentinels for the detection of the parasite's transmission into marine ecosystems. Toxoplasmosis is a major cause of mortality and contributor to the slow rate of population recovery for southern sea otters in California. An updated seroprevalence analysis showed that 52% of 305 freshly dead, beachcast sea otters and 38% of 257 live sea otters sampled along the California coast from 1998 to 2004 were infected with T. gondii. Areas with high T. gondii exposure were predominantly sandy bays near urban centres with freshwater runoff. Genotypic characterisation of 15 new T. gondii isolates obtained from otters in 2004 identified only X alleles at B1 and SAG1. A total of 38/50 or 72% of all otter isolates so far examined have been infected with a Type X strain. Type X isolates were also obtained from a Pacific harbor seal (Phoca vitulina) and California sea lion (Zalophus californianus). Molecular analysis using the C8 RAPD marker showed that the X isolates were more genetically heterogeneous than archetypal Type I, II and III genotypes of T. gondii. The origin and transmission of the Type X T. gondii genotype are not yet clear. Sea otters do not prey on known intermediate hosts for T. gondii and vertical transmission appears to play a minor role in maintaining infection in the populations. Therefore, the most likely source of infection is by infectious, environmentally resistant oocysts that are shed in the feces of felids and transported via freshwater runoff into the marine ecosystem. As nearshore predators, otters serve as sentinels of protozoal pathogen flow into the marine environment since they share the same environment and consume some of the same foods as humans. Investigation into the processes promoting T. gondii infections in sea otters will provide a better understanding of terrestrial parasite flow and the emergence of disease

  3. Isolation and RFLP genotyping of Toxoplasma gondii from the mongoose (Herpestes auropunctatus) in Grenada, West Indies.

    PubMed

    Choudhary, Shanti; Zieger, Ulrike; Sharma, Ravindra N; Chikweto, Alfred; Tiwari, Keshaw P; Ferreira, Leandra R; Oliveira, Solange; Barkley, Lovell J; Verma, Shiv Kumar; Kwok, Oliver C H; Su, Chunlei; Dubey, J P

    2013-12-01

    Little is known of the genetic diversity and epidemiology of Toxoplasma gondii infection in wildlife in Caribbean Islands. The prevalence and genetic diversity of T. gondii in mongooses (Herpestes auropunctatus) was investigated. During 2011 and 2012, 91 mongooses were trapped in different parts of Grenada, bled, euthanized, and examined at necropsy. Antibodies to T. gondii were found in 27 mongooses tested by the modified agglutination test (cut-off titer 25). Muscles (heart, tongue, neck) of 25 of the seropositive mongooses were bioassayed for T. gondii infection in mice. Viable T. gondii was isolated by bioassay in mice from four mongooses with MAT titers of 1:50 in two, 1:200 for one, and 1:400 for one mongoose. The four T. gondii isolates were further propagated in cell culture. Strain typing of T. gondii DNA extracted from cell-cultured tachyzoites using the 10 PCR-restriction fragment length polymorphism (RFLP) markers SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico revealed one isolate belongs to the Type III (ToxoDB #2) lineage, two to ToxoDB#7 lineage, and one to the ToxoDB #216 lineage. This is the first report of T. gondii isolation and genotyping in H. auropunctatus worldwide.

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

    PubMed

    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.

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

    PubMed

    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.

  6. Dual Sarcocystis neurona and Toxoplasma gondii infection in a northern sea otter from Washington state, USA

    USGS Publications Warehouse

    Lindsay, D.S.; Thomas, N.J.; Rosypal, A.C.; Dubey, J.P.

    2001-01-01

    Dual Sarcocystis neurona and Toxoplasma gondii infection was observed in a Northern sea otter from Washington, USA. The animal was found stranded, convulsed, and died shortly thereafter. Encephalitis caused by both S. neurona and T. gondii was demonstrated in histological sections of brain. Immunohistochemical examination of sections with S. neurona specific antisera demonstrated developmental stages that divided by endopolygeny and produced numerous merozoites. PCR of brain tissue from the sea otter using primer pairs JNB33/JNB54 resulted in amplification of a 1100 bp product. This PCR product was cut in to 884 and 216 bp products by Dra I but was not cut by Hinf I indicating that it was S. neurona [J. Parasitol. 85 (1999) 221]. No PCR product was detected in the brain of a sea otter which had no lesions of encephalitis. Examination of brain sections using T. gondii specific antisera demonstrated tachyzoites and tissue cysts of T. gondii. The lesions induced by T. gondii suggested that the sea otter was suffering from reactivated toxoplasmosis. T. gondii was isolated in mice inoculated with brain tissue. A cat that was fed infected mouse brain tissue excreted T. gondii oocysts which were infective for mice. This is apparently the first report of dual S. neurona and T. gondii in a marine mammal.

  7. Occurrence of Toxoplasma gondii in Carcasses of Pigs Reared in Intensive Systems in Northern Italy.

    PubMed

    Papini, Roberto; di Ciccio, Pierluigi; Marangi, Marianna; Ghidini, Sergio; Zanardi, Emanuela; Vergara, Alberto; Giangaspero, Annunziata; Nardoni, Simona; Rocchigiani, Guido; Mancianti, Francesca; Ianieri, Adriana

    2017-03-01

    To evaluate the occurrence of Toxoplasma gondii and to genetically characterize its isolates in carcasses of industrial fattening pigs, blood, diaphragm, and heart samples were collected from 375 carcasses of pigs slaughtered to be processed for Parma ham production. Pigs had been bred on approved farms (n = 75) located in the so-called Food Valley in Italy. Sera were examined for immunoglobulin G antibodies to T. gondii by modified agglutination test (MAT). Both heart and diaphragm samples from seropositive carcasses were processed for the presence of T. gondii DNA (B1 locus) by real-time PCR and high resolution melting (HRM) assay. Anti-Toxoplasma antibodies were detected in 2.1% of pig carcasses, with titers from 1:10 to 1:320. T. gondii DNA was detected in all (eight) seropositive carcasses and in 11 (5 heart and 6 diaphragm samples) of 16 samples; that is, it was detected in heart tissue in two subjects, in diaphragm tissue in three subjects, and in both muscle tissues in three subjects. Toxoplasma genotypes were determined in seven of eight carcasses: type III was identified in four carcasses, type II in two, and both III and II in one carcass. The serological findings and the molecular detection of T. gondii strains suggest that cured meat products obtained from industrially bred pigs may be potential sources of toxoplasmosis for humans. Our results provide novel, important information regarding the seroprevalence and molecular prevalence of T. gondii in intensively reared pigs within this specific region of Italy, particularly because Parma ham from this region is known and consumed worldwide. On-farm preventive measures combined with slaughterhouse monitoring of carcasses of pigs bred for cured meat production should never be overlooked to prevent the introduction of T. gondii into the food chain and to ensure safety for consumers of these products.

  8. Comparison of different commercial serological tests for the detection of Toxoplasma gondii antibodies in serum of naturally exposed pigs.

    PubMed

    Steinparzer, R; Reisp, K; Grünberger, B; Köfer, J; Schmoll, F; Sattler, T

    2015-03-01

    Toxoplasma gondii is the aetiological agent of the zoonotic disease toxoplasmosis and transmitted among other ways by chemically and physically untreated, that is, raw pork to humans. The detection of Toxoplasma gondii is impossible by currently practiced meat inspection, but serological tests can be used to detect Toxoplasma gondii antibodies in pig herds and can consequently be helpful to identify potentially contaminated pork. Therefore, appropriate serological tests are required. In this study, serum samples of 1368 naturally exposed slaughter pigs from 73 Austrian farms were collected. Serum samples of at least 16 slaughter pigs per farm were tested. The prevalence of Toxoplasma gondii antibodies in serum was measured by a commercial available modified agglutination test (MAT) and compared to three different commercial available enzyme-linked immunosorbent assays (ELISA). The MAT detected 6.5%, ELISA I 6.7%, ELISA II 4.8% and ELISA III 4.3% of the pigs as Toxoplasma gondii antibody positive. The agreement, according to the kappa coefficient (κ), was substantial between the MAT and ELISA I (κ = 0.62), II (κ = 0.64) and III (κ = 0.67). A better agreement was determined between ELISA I and II (κ = 0.715), ELISA I and III (κ = 0.747) and ELISA II and III (κ = 0.865). At least one pig per farm was detected Toxoplasma gondii antibody positive in 17 (23.3%) farms by the MAT, 26 (35.6%) farms by ELISA I, 16 (21.9%) farms by ELISA II and 11 (15.1%) farms by ELISA III. Pig farms with a high number of Toxoplasma gondii antibody-positive pigs or high antibody titres were identified by all of the four used serological tests. Concerning the occurrence of Toxoplasma gondii antibodies in Austrian pig farms, a monitoring and surveillance programme would be reasonable to find high-risk farms.

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

    PubMed Central

    2012-01-01

    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. PMID:22992281

  10. Evaluation of Anti-Toxoplasma gondii Antibodies in Hemodialysis Patients with Chronic Kidney Disease in Sari, Iran

    PubMed Central

    Seyyedpour, Seyyed Hosein; Afshar, Parvaneh; Barzegarnejad, Ayoub; Kalhori, Shamsi; Agah, Reza

    2016-01-01

    Background Toxoplasma gondii has worldwide distribution and is one of the most prevalent infectious agents in humans. Objectives The aim of this study was to determine the prevalence of anti-Toxoplasma gondii antibodies in hemodialysis patients with chronic kidney disease (CKD) in the hemodialysis unit of Fatemeh Zahra hospital at the Mazandaran University of Medical Sciences in Sari, Iran. Methods Seventy-three patients with CKD and 145 healthy volunteers were assessed for anti-Toxoplasma gondii (IgG, IgM, and IgA) antibodies using a conventional ELISA technique. Results The anti-Toxoplasma gondii IgG antibody was detected in 80.8% of the cases in the patient group, while 31.5% of the cases in the CKD patient group and 31.8% in the control group were found to be positive for the anti-Toxoplasma gondii IgA antibody. All the patients in the CKD group were negative for the anti-Toxoplasma gondii IgM antibody, although 2.76% of the healthy volunteers were found to be positive. The present study suggests that there was no significant difference between the hemodialysis patient group and the healthy volunteers. Conclusions The epidemiological data collected in this study could serve as a reference for future studies and may be useful in developing preventive and educational strategies, and consequently reducing healthcare expenditure. PMID:27896240

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

    USGS Publications Warehouse

    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.

  12. Seroprevalence of Toxoplasma gondii in pregnant women and cats in Grenada, West Indies.

    PubMed

    Asthana, Sumita P; Macpherson, Calum N L; Weiss, Stanley H; Stephens, Richard; Denny, Thomas N; Sharma, R N; Dubey, J P

    2006-06-01

    Prevalence of antibodies against Toxoplasma gondii was studied in 534 pregnant women and 40 domestic cats in Grenada, West Indies. Antibodies (IgG) for T. gondii were sought in human sera by an enzyme-linked immunosorbent assay and in cat sera by using the modified agglutination test (MAT). Antibodies were found in 57 % of pregnant women. Seroprevalence increased with age; 51% of 15- to 19-yr-old women (100 total) had antibodies versus 60% of 20- to 24-yr-old women (127 total). Antibodies to T. gondii (MAT, 1:25 serum dilution) were found in 35% of cats; titers were 1:25 in 7 cats, 1:50 in 4 cats, and 1:500 in 3 cats. Epidemiological data suggested that the ingestion of food or water contaminated with oocysts was an important mode of transmission of T. gondii to women.

  13. Seroprevalence of Toxoplasma gondii infection in domestic cats in central China

    PubMed Central

    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 < 0.05) was observed in mixed-breed cats (24%) compared to purebred cats (17%). Seroprevalence in rural cats (29%) was significantly higher (p < 0.01) than in urban cats (16%), and increased significantly (p < 0.01) with age. These results showed that T. gondii was highly prevalent in domestic cats in Henan province, central China, which might have important implications for public health. PMID:28322721

  14. Reciprocal virulence and resistance polymorphism in the relationship between Toxoplasma gondii and the house mouse.

    PubMed

    Lilue, Jingtao; Müller, Urs Benedikt; Steinfeldt, Tobias; Howard, Jonathan C

    2013-10-29

    Virulence in the ubiquitous intracellular protozoon Toxoplasma gondii for its natural intermediate host, the mouse, appears paradoxical from an evolutionary standpoint because death of the mouse before encystment interrupts the parasite life cycle. Virulent T. gondii strains secrete kinases and pseudokinases that inactivate the immunity-related GTPases (IRG proteins) responsible for mouse resistance to avirulent strains. Such considerations stimulated a search for IRG alleles unknown in laboratory mice that might confer resistance to virulent strains of T. gondii. We report that the mouse IRG system shows extraordinary polymorphic complexity in the wild. We describe an IRG haplotype from a wild-derived mouse strain that confers resistance against virulent parasites by interference with the virulent kinase complex. In such hosts virulent strains can encyst, hinting at an explanation for the evolution of virulence polymorphism in T. gondii. DOI:http://dx.doi.org/10.7554/eLife.01298.001.

  15. Genotyping of Toxoplasma gondii Isolates from Wild Boars in Peninsular Malaysia

    PubMed Central

    Puvanesuaran, Vignesh R.; Noordin, Rahmah; Balakrishnan, Venugopal

    2013-01-01

    Toxoplasma gondii is a parasitic protozoan that infects nearly one-third of the world population. The present study was done to isolate and genotype T. gondii from wild boar from forests of Pahang, Malaysia. A total of 30 wild boars' blood, heads and hearts were obtained for this study and 30 (100.0%) were found to be seropositive when assayed with modified agglutination test (MAT≥6). The positive samples were inoculated into mice and T. gondii was only isolated from samples that had strong seropositivity (MAT≥1∶24).The isolates were subjected to PCR-RFLP analysis and all the Peninsular Malaysia isolates of T. gondii are of clonal type I. PMID:23613920

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

    PubMed Central

    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. PMID:27200271

  17. Local admixture of amplified and diversified secreted pathogenesis determinants shapes mosaic Toxoplasma gondii genomes

    PubMed Central

    Lorenzi, Hernan; Khan, Asis; Behnke, Michael S.; Namasivayam, Sivaranjani; Swapna, Lakshmipuram S.; Hadjithomas, Michalis; Karamycheva, Svetlana; Pinney, Deborah; Brunk, Brian P.; Ajioka, James W.; Ajzenberg, Daniel; Boothroyd, John C.; Boyle, Jon P.; Dardé, Marie L.; Diaz-Miranda, Maria A.; Dubey, Jitender P.; Fritz, Heather M.; Gennari, Solange M.; Gregory, Brian D.; Kim, Kami; Saeij, Jeroen P. J.; Su, Chunlei; White, Michael W.; Zhu, Xing-Quan; Howe, Daniel K.; Rosenthal, Benjamin M.; Grigg, Michael E.; Parkinson, John; Liu, Liang; Kissinger, Jessica C.; Roos, David S.; David Sibley, L

    2016-01-01

    Toxoplasma gondii is among the most prevalent parasites worldwide, infecting many wild and domestic animals and causing zoonotic infections in humans. T. gondii differs substantially in its broad distribution from closely related parasites that typically have narrow, specialized host ranges. To elucidate the genetic basis for these differences, we compared the genomes of 62 globally distributed T. gondii isolates to several closely related coccidian parasites. Our findings reveal that tandem amplification and diversification of secretory pathogenesis determinants is the primary feature that distinguishes the closely related genomes of these biologically diverse parasites. We further show that the unusual population structure of T. gondii is characterized by clade-specific inheritance of large conserved haploblocks that are significantly enriched in tandemly clustered secretory pathogenesis determinants. The shared inheritance of these conserved haploblocks, which show a different ancestry than the genome as a whole, may thus influence transmission, host range and pathogenicity. PMID:26738725

  18. Toxoplasma gondii in horse meat intended for human consumption in Romania.

    PubMed

    Paştiu, Anamaria Ioana; Györke, Adriana; Kalmár, Zsuzsa; Bolfă, Pompei; Rosenthal, Benjamin Martin; Oltean, Miruna; Villena, Isabelle; Spînu, Marina; Cozma, Vasile

    2015-09-15

    The prevalence of Toxoplasma gondii, an economically important zoonotic protozoan, was investigated in horses slaughtered for export and human consumption in the North of Romania. Pairs of samples, sera and heart tissues, were collected from 82 slaughtered horses. Examination of horse sera by ELISA at a dilution of 1:10, and by modified agglutination test (MAT) at a dilution of 1:6, revealed that 32 (39%) and 31(37.8%) horses, respectively, had antibodies against T. gondii. Using polymerase chain reaction (PCR) analysis, T. gondii DNA was not found in any heart sample collected from horses. By bioassay in mice, we obtained viable isolates of T. gondii from two of ten horses determined to be strongly positive by serological assay/ELISA. The prevalence estimated in horses highlighted the potential risk for human contamination by consumption of raw or undercooked meat.

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

    PubMed

    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.

  20. Effects of muramyl dipeptide treatment on resistance to infection with Toxoplasma gondii in mice.

    PubMed Central

    Krahenbuhl, J L; Sharma, S D; Ferraresi, R W; Remington, J S

    1981-01-01

    Studies were carried out to determine whether treatment of mice with the synthetic adjuvant muramyl dipeptide afforded any resistance to infection with the obligate intracellular protozoan Toxoplasma gondii. Marked resistance to lethal challenge infection was observed in CBA but not C57BL/6 mice pretreated with muramyl dipeptide. In CBA mice, a single muramyl dipeptide treatment administered 14, 7, or 4 days before Toxoplasma challenge did not afford protection, whereas mice treated at -1 day were highly resistant. Additional studies carried out to investigate the mechanisms underlying the enhanced resistance to Toxoplasma in muramyl dipeptide-treated mice failed to reveal either enhanced cytolytic antibodies to the parasite or evidence that peritoneal macrophages from treated mice were activated as determined in vitro by their microbicidal capacity for Toxoplasma or cytotoxic capacity for tumor target cells. PMID:7216470

  1. Solution structure and dynamics of ADF from Toxoplasma gondii.

    PubMed

    Yadav, Rahul; Pathak, Prem Prakash; Shukla, Vaibhav Kumar; Jain, Anupam; Srivastava, Shubhra; Tripathi, Sarita; Krishna Pulavarti, S V S R; Mehta, Simren; Sibley, L David; Arora, Ashish

    2011-10-01

    Toxoplasma gondii ADF (TgADF) belongs to a functional subtype characterized by strong G-actin sequestering activity and low F-actin severing activity. Among the characterized ADF/cofilin proteins, TgADF has the shortest length and is missing a C-terminal helix implicated in F-actin binding. In order to understand its characteristic properties, we have determined the solution structure of TgADF and studied its backbone dynamics from ¹⁵N-relaxation measurements. TgADF has conserved ADF/cofilin fold consisting of a central mixed β-sheet comprised of six β-strands that are partially surrounded by three α-helices and a C-terminal helical turn. The high G-actin sequestering activity of TgADF relies on highly structurally and dynamically optimized interactions between G-actin and G-actin binding surface of TgADF. The equilibrium dissociation constant for TgADF and rabbit muscle G-actin was 23.81 nM, as measured by ITC, which reflects very strong affinity of TgADF and G-actin interactions. The F-actin binding site of TgADF is partially formed, with a shortened F-loop that does not project out of the ellipsoid structure and a C-terminal helical turn in place of the C-terminal helix α4. Yet, it is more rigid than the F-actin binding site of Leishmania donovani cofilin. Experimental observations and structural features do not support the interaction of PIP2 with TgADF, and PIP2 does not affect the interaction of TgADF with G-actin. Overall, this study suggests that conformational flexibility of G-actin binding sites enhances the affinity of TgADF for G-actin, while conformational rigidity of F-actin binding sites of conventional ADF/cofilins is necessary for stable binding to F-actin.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 pu...

  3. Comparative sequence analysis of Toxoplasma gondii reveals local genomic admixture drives concerted expansion and diversification of secreted pathogenesis determinants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Toxoplasma gondii is among the most prevalent parasites worldwide, infecting many wild and domestic animals and causing zoonotic infections in humans. T. gondii differs substantially in its broad distribution from closely related parasites that typically have narrow, specialized host ranges. To un...

  4. The zebrafish, Danio rerio, as a model for Toxoplasma gondii: an initial description of infection in fish

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Toxoplasma gondii infects a very wide range of mammals and birds, and about one-third of humans are infected with this protozoan parasite. Chronic T. gondii infection has historically been believed to be asymptomatic; however there is now evidence that suggest an association of seropositivity with s...

  5. Comparative genomic sequence variation of Toxoplasma gondii reveals local admixture drives concerted expansion and diversification of secreted pathogenesis determinants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Toxoplasma gondii is among the most abundant parasites world-wide, infecting many wild and domestic animals and causing zoonotic infections in humans. T. gondii differs substantially in its distribution from closely related parasites that typically have narrow, specialized host ranges. We undertook...

  6. Seroprevalence of Toxoplasma gondii infection in water buffaloes (Bubalus bubalis) in Veracruz State, Mexico and its association with climatic factors

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background: Infection with Toxoplasma gondii in water buffaloes (Bubalus bubalis) is of epidemiological importance because of the risk for transmission to humans. We sought to determine the seroprevalence of T. gondii infection in 339 water buffaloes in Veracruz State, Mexico using the modified aggl...

  7. Study of the relationship between Toxoplasma gondii infection and food source in seagull chicks from breeding areas from Spain

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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. Sera from 525 seagull chicks from 6 ...

  8. Seroprevalence of Toxoplasma gondii in wild marsupials and rodents from the Atlantic forest of Pernambuco State, Northeastern region, Brazil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  9. Occurrence, isolation, and genetic characterization of Toxoplasma gondii from white tailed deer (Odocoileus virginianus) in New Jersey

    Technology Transfer Automated Retrieval System (TEKTRAN)

    White tailed deer (WTD) is an important reservoir host for Toxoplasma gondii. Each yr hundreds of thousands WTD are hunted or die in road accidents in the U.S.A. Humans and animals can become infected with T. gondii by eating infected venison. Wild felids that eat infected deer tissues can shed oocy...

  10. Seroprevalence of Toxoplasma gondii and Neospora caninum in feral cats (Felis silvestris catus) in Majorca, Balearic Islands, Spain

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  11. Toxoplasmosis in geese and detection of two new atypical Toxoplasma gondii strains from naturally infected Canada geese (Branta canadensis)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 ...

  12. Genetic characterization of Toxoplasma gondii in wildlife from North America revealed widespread and high prevalence of the fourth clonal type

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Little is known of the genetic diversity of Toxoplasma gondii circulating in wildlife. In the present study, wild animals, including dolphins from the USA were examined for T. gondii infection. Tissues of naturally exposed animals were bioassayed in mice for isolation of viable parasites. Viable T. ...

  13. Isolation and genetic characterization of Toxoplasma gondii from naturally infected Canada goose (Branta canadensis) detected two new atypical strains

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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. Prevalence of Toxoplasma gondii antibodies in domestic donkeys (Equus asinus) in Durango, Mexico slaughtered for human consumption

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background: 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 Dur...

  15. Genetic characterization of Toxoplasma gondii isolates from Portugal, Austria, and Israel reveals higher genetic variability within the type II lineage

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study compared genetic diversity of Toxoplasma gondii isolates from Portugal, Austria and Israel. For this, we genotyped 90 T. gondii isolates (16 from Portugal, 67 from Austria and 7 from Israel) using 10 nested PCR-restriction length polymorphism (RFLP) genetic markers and 15 microsatellite (...

  16. Seroprevalence and correlates of Toxoplasma gondii infection in domestic sheep in Michoacán State, Mexico

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Toxoplasma gondii infection in sheep is of public health and economic importance. Seroprevalence of T. gondii infection and correlates were determined in 405 sheep from 7 farms in 4 geographical regions in Michoacán State, Mexico using the modified agglutination test (MAT). General sheep and environ...

  17. Seroepidemiology of infection with Toxoplasma gondii in workers occupationally exposed to water, sewage, and soil in Durango, Mexico

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  18. Occurrence of Toxoplasma gondii antibodies in wild rodents and marsupials from the Atlantic forest, State of Sao Paulo, Brazil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Toxoplasma gondii is a protozoan parasite that infects a large spectrum of warm-blooded animals, including humans. Small mammals and rodents play an important role in the epidemiology of T. gondii because they are sources of infection for domestic and feral cats. Serum samples from 151 rodents and 4...

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

    PubMed Central

    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

  20. Risk factors for Toxoplasma gondii exposure in semiaquatic mammals in a freshwater ecosystem.

    PubMed

    Ahlers, Adam A; Mitchell, Mark A; Dubey, Jitender P; Schooley, Robert L; Heske, Edward J

    2015-04-01

    We assessed risk factors for Toxoplasma gondii exposure in semiaquatic mammals in east-central Illinois, US. This agricultural region has extensive drainage systems that could potentially transport T. gondii oocysts into the watershed. We used muskrats (Ondatra zibethicus) and American mink (Neovison vison) as sentinels of watershed contamination. We predicted individuals from larger subwatersheds would more likely be antibody-positive for T. gondii, as they were exposed to drainage from larger areas. We also evaluated amount of urban land cover within the subwatershed, proximity to farmsteads, and age of individuals in competing models of T. gondii infection. Antibodies to T. gondii were assayed in animal sera by modified agglutination tests (titer 25 or higher) and detected in 18 (60%) of 30 muskrats and 20 (77%) of 26 mink. Infection rates were ≥1.7 times higher than those typical for mammals in upland habitats in this region. Subwatershed size and age class were important predictors of T. gondii infection in muskrats (R(2) = 0.35). Models incorporating urban land cover and proximity to farmsteads had little support. None of our models of antibody prevalence in mink were well supported, possibly because mink are less strictly associated with riparian habitats. Because ~91% of our study area is devoted to agricultural production and urbanization, transport of T. gondii into freshwater ecosystems is likely facilitated by modified drainage practices common in these areas.

  1. Expression of Toxoplasma gondii dense granule protein7 (GRA7) in Eimeria tenella.

    PubMed

    Yin, Guangwen; Qin, Mei; Liu, Xianyong; Suo, Jingxia; Suo, Xun

    2013-05-01

    Dense granules are specialized secretory organelles of Apicomplexa parasites; the dense granule (GRA) proteins are believed to play a role in intracellular survival and the nutrient/waste exchange mechanism with the host cell. Until now, limited information is available concerning the characterization of GRA proteins in Eimeria. Eimeria tenella and Toxoplasma gondii are apicomplexan protozoa and share many similarities in biology and genomics. We hypothesized that GRA proteins from T. gondii could be expressed and have a similar function in E. tenella. To confirm the expression and localization of the GRA protein in T. gondii and E. tenella, a transient transfection strategy was used to express T. gondii GRA7 tagged with yellow fluorescent protein (YFP) (GRA7-YFP); T. gondii tachyzoites were transfected with the plasmid pTgtubGRA7-YFP/sagCAT, and E. tenella sporozoites were transfected with the pEtmic1GRA7-YFP/act construct. The results show that fluorescence can be expressed mainly into the parasitophorous vacuoles (PVs) of the T. gondii. GRA7 of T. gondii can also be expressed in E. tenella and can lead the fluorescence protein into the PVs of the parasites and the cavity of the sporocysts. As for the extracellular stage, YFP gathered to form small particles in the released merozoites and sporozoites, suggesting a localization of the secretory organelles of E. tenella. These results suggest that GRA proteins have a conserved function across species of Apicomplexa in targeting proteins to the PVs.

  2. Toxoplasma gondii antibody titers and history of suicide attempts in patients with schizophrenia.

    PubMed

    Okusaga, Olaoluwa; Langenberg, Patricia; Sleemi, Aamar; Vaswani, Dipika; Giegling, Ina; Hartmann, Annette M; Konte, Bettina; Friedl, Marion; Groer, Maureen W; Yolken, Robert H; Rujescu, Dan; Postolache, Teodor T

    2011-12-01

    Toxoplasma gondii (T. gondii) a widespread neurotropic parasite, has been previously associated with schizophrenia and more recently with suicidal behavior. However, no previous study has examined the association of T. gondii with suicidal behavior in schizophrenia patients. 950 individuals diagnosed with schizophrenia by SCID were recruited from the Munich area of Germany. Solid-enzyme immunoassay methods were used to measure IgG plasma antibodies to T. gondii, other neurotropic pathogens and gliadin. Logistic regression models were developed to analyze the association of T. gondii seropositivity or serointensity with history of suicidal behavior. In those younger than the median age of the sample, 38, T. gondii serointensity was associated with history of suicidal behavior (p = 0.02), while in the older patients the relationship was not significant (p = 0.21). Seropositivity was also associated with history of suicide attempt in younger patients, odds ratio 1.59 (95% CI 1.06 to 2.40), p = 0.03. Seropositivity for CMV (p = 0.22), HSV-1 (p = 0.36) and gliadin (p = 0.92) was not related to history of suicide attempt in the entire sample or any age subgroup. T. gondii serology might become, with interaction with vulnerability genes, a candidate biomarker for a subgroup of schizophrenia patients prone to attempting suicide.

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

    PubMed Central

    2014-01-01

    Background 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 modified agglutination test (MAT, cut off 1:25). Results Sixty eight (67.3%) of 101 dogs were seropositive with titers of 1:25 in 16, 1:50 in 8, 1:100 in 9, 1:200 in 10, 1:400 in 10, 1:800 in 10, 1:1600 in 3, and 1:3200 or higher in 2. None of the dogs’ characteristics studied including age, sex, breed, and history of deworming, rabies vaccination and contact with cats was associated with seroprevalence of T. gondii infection. Conclusion Using the dogs as sentinel animals, the results indicate high contamination with T. gondii of the environment in Veracruz, Mexico. Results have public health implications, and further studies in Veracruz should be conducted to establish the sources of environmental contamination with T. gondii and to determine optimal preventive measures against T. gondii infection in humans. PMID:25134696

  4. Genetic Characterization of Toxoplasma gondii from Zoo Wildlife and Pet Birds in Fujian, China

    PubMed Central

    CHEN, Renfeng; LIN, Xuan; HU, Lingying; CHEN, Xiaoli; TANG, Yao; ZHANG, Jia; CHEN, Meizhen; WANG, Shoukun; HUANG, Cuiqin

    2015-01-01

    Background: Toxoplasmosis, a worldwide zoonotic disease, is caused by Toxoplasma gondii. The distribution of genetic diversity of T. gondii in wild animals is of great importance to understand the transmission of the parasite in the environment. However, little is known about T. gondii prevalence in wild animals and birds in China. Methods: We conducted the genetic characterization of T. gondii isolated from Zoo Wild Animals and Pet Birds in Fujian Province, Southeastern China. Heart tissues were collected from 45 zoo animals and 140 pet birds. After identified using B1 gene, the genetic diversity of T. gondii isolates were typed at 11 genetic markers, including SAG1, 5’ and 3’-SAG2, alternative SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, Apico, and CS3. Results: Seven of 45 zoo animals and 3 of 140 pet birds were positive by PCR amplification using T. gondii B1 gene specific primers. Of these positive isolates, 3 isolates from Black-capped (Cebus apella), Peacock (Peafowl) and Budgerigar (Melopsittacus undulatus) were successfully genotyped at 11 genetic loci, and grouped to three distinct genotypes: ToxoDB Genotype #9, #2 and #10, respectively. Conclusion: This is the first genotyping of T. gondii isolated from zoo wild animals and pet birds in Fujian, China. There is a potential risk for the transmission of this parasite through zoo wild animals and pet birds in this region. PMID:26811736

  5. Murine guanylate binding protein 2 (mGBP2) controls Toxoplasma gondii replication.

    PubMed

    Degrandi, Daniel; Kravets, Elisabeth; Konermann, Carolin; Beuter-Gunia, Cornelia; Klümpers, Verena; Lahme, Sarah; Wischmann, Eva; Mausberg, Anne K; Beer-Hammer, Sandra; Pfeffer, Klaus

    2013-01-02

    IFN-γ orchestrates the host response against intracellular pathogens. Members of the guanylate binding proteins (GBP) comprise the most abundant IFN-γ-induced transcriptional response. mGBPs are GTPases that are specifically up-regulated by IFN-γ, other proinflammatory cytokines, toll-like receptor agonists, as well as in response to Listeria monocytogenes and Toxoplasma gondii infection. mGBP2 localizes at the parasitophorous vacuole (PV) of T. gondii; however, the molecular function of mGBP2 and its domains in T. gondii infection is not known. Here, we show that mGBP2 is highly expressed in several cell types, including T and B cells after stimulation. We provide evidence that the C-terminal domain is sufficient and essential for recruitment to the T. gondii PV. Functionally, mGBP2 reduces T. gondii proliferation because mGBP2-deficient cells display defects in the replication control of T. gondii. Ultimately, mGBP2-deficient mice reveal a marked immune susceptibility to T. gondii. Taken together, mGBP2 is an essential immune effector molecule mediating antiparasitic resistance.

  6. Seroprevalence of Toxoplasma gondii in pigs, sheep, goats, and cattle from Grenada and Carriacou, West Indies.

    PubMed

    Chikweto, A; Kumthekar, S; Tiwari, K; Nyack, B; Deokar, M S; Stratton, G; Macpherson, C N L; Sharma, R N; Dubey, J P

    2011-10-01

    Prevalence of Toxoplasma gondii infection in pregnant women in Grenada is considered high. Little is known of the epidemiology of T. gondii infection in Caribbean Islands. Serum samples of 750 food animals in Grenada and Carriacou were tested for antibodies to T. gondii by the modified agglutination test (MAT). Antibodies to T. gondii (MAT, 1∶25 or higher) were found in 23.1% of 247 pigs, 44.1% of 204 sheep, 42.8% of 180 goats, and 8.4% of 119 cattle. Seroprevalence increased with age, indicating postnatal acquisition of T. gondii. Antibody titers of 1∶200 or higher were present in 65 of 90 seropositive sheep, 61 of 77 seropositive goats, and 23 of 57 seropositive pigs. However, none of the cattle had a MAT titer of 1∶200, suggesting that bovines are a poor host for T. gondii. Results indicate that pigs, sheep, and goats could be important sources of T. gondii infection if their meat is consumed undercooked.

  7. Sterculic Acid and Its Analogues Are Potent Inhibitors of Toxoplasma gondii

    PubMed Central

    Hao, Pan; Alaraj, Intisar Q. M.; Dulayymi, Juma’a R. Al; Baird, Mark S.; Liu, Jing; Liu, Qun

    2016-01-01

    Toxoplasmosis is a serious disease caused by Toxoplasma gondii, one of the most widespread parasites in the world. Lipid metabolism is important in the intracellular stage of T. gondii. Stearoyl-CoA desaturase (SCD), a key enzyme for the synthesis of unsaturated fatty acid is predicted to exist in T. gondii. Sterculic acid has been shown to specifically inhibit SCD activity. Here, we examined whether sterculic acid and its methyl ester analogues exhibit anti-T. gondii effects in vitro. T. gondii-infected Vero cells were disintegrated at 36 hr because of the propagation and egress of intracellular tachyzoites. All test compounds inhibited tachyzoite propagation and egress, reducing the number of ruptured Vero cells by the parasites. Sterculic acid and the methyl esters also inhibited replication of intracellular tachyzoites in HFF cells. Among the test compounds, sterculic acid showed the most potent activity against T. gondii, with an EC50 value of 36.2 μM, compared with EC50 values of 248-428 μM for the methyl esters. Our study demonstrated that sterculic acid and its analogues are effective in inhibition of T. gondii growth in vitro, suggesting that these compounds or analogues targeting SCD could be effective agents for the treatment of toxoplasmosis. PMID:27180571

  8. Prevalence of anti-Toxoplasma gondii antibody in domestic horses in Japan.

    PubMed

    Masatani, Tatsunori; Takashima, Yasuhiro; Takasu, Masaki; Matsuu, Aya; Amaya, Tomohiko

    2016-04-01

    The present study is the first report that investigated the seroprevalence of Toxoplasma gondii infection in domestic horses in various prefectures of Japan and analyzed risk factors for seropositivity. We performed a latex agglutination test for riding/racing horses from 11 prefectures in Japan (783 samples) and 4 groups of Japanese native horses (254 samples). The total seroprevalence of anti-T. gondii antibody in horses examined in this study was 4.24% (44/1037). As for riding/racing horses, we did not find a statistically different T. gondii seroprevalence between sampling prefectures. In contrast, seroprevalence of T. gondii in older horses (>21 years) was significantly higher than that in younger horses (<5 years and 11-15 years). There was no significant difference in T. gondii seroprevalence between riding/racing horses and Japanese native horses. Logistical regression analysis revealed that age, but not sex and usage, is a significant risk factor of T. gondii infection for domestic horses in Japan. These findings suggest that domesticated horses in Japan can be horizontally infected with T. gondii by ingestion of food or water contaminated with oocysts.

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

    PubMed

    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.

  10. Human lymphokine-activated killer cells are cytotoxic against cells infected with Toxoplasma gondii

    PubMed Central

    1992-01-01

    Experiments were conducted to determine whether human lymphokine- activated killer (LAK) cells are cytotoxic against cells infected with Toxoplasma gondii. Nylon wool nonadherent (NWNA) peripheral blood lymphocytes, as well as purified natural killer cell (NK) (CD3- CD16+ CD56+) and T (CD3+ CD16- CD56-) cells obtained from five healthy T. gondii seronegative volunteers exhibited minimal cytotoxic activity against T. gondii-infected cells. When standard LAK (S-LAK) cell preparations were induced by incubation of NWNA cells with recombinant interleukin 2, induction of remarkable cytotoxic activity against T. gondii-infected cells. When standard in LAK cell preparations from each of the volunteers. The phenotype of the LAK precursor and effector cells varied depending on the target cell used. Whereas the precursor and the effector cells of most of the LAK activity against K562 and Daudi cells were cells with NK phenotype, when T. gondii-infected cells were used as targets, both cells with NK and T cell phenotypes were precursors and effectors of the lysis. When cytotoxic activity of S-LAK cells was compared with the activity of adherent LAK (A-LAK) cells, A- LAK cells displayed higher cytotoxic activity against T. gondii- infected cells, as well as against K562 and Daudi cells. Cold target inhibition experiments suggested that there is a subset of LAK effector cells capable of lysing both T. gondii-infected cells and Daudi cells, whereas other subsets preferentially or exclusively lyse one of these target cells. PMID:1460415

  11. Silencing of GRA10 protein expression inhibits Toxoplasma gondii intracellular growth and development.

    PubMed

    Witola, William H; Bauman, Bretta; McHugh, Mark; Matthews, Kwame

    2014-10-01

    Toxoplasma gondii dense granule proteins (GRAs) are secreted abundantly in both the tachyzoite and bradyzoite stages of the parasite and are known to localize to various compartments of the parasitophorous vacuole (PV) that interfaces with the host cell milieu. Thus, GRAs may play significant roles in the biogenesis of the PV that is important for survival of intracellular T. gondii. GRA10 is a dense granule protein whose role in T. gondii has not yet been characterized. Therefore, in this study, we endeavored to determine the role of GRA10 in the growth and survival of intracellular T. gondii by using phosphorodiamidate morpholino oligomers (PPMOs) antisense knockdown approach to disrupt the translation of GRA10 mRNA in the parasites. We expressed and purified a truncated recombinant GRA10 protein to generate anti-GRA10 polyclonal antibodies that we used to characterize GRA10 in T. gondii. We found that GRA10 is a soluble, dense granule-associated protein that is secreted into the parasite cytosol and the parasitophorous vacuole milieu. Using in vitro cultures, we found that knockdown of GRA10 results in severe inhibition of T. gondii growth in human fibroblasts and in ovine monocytic cells. Together, our findings define GRA10 as a dense granule protein that plays a significant role in the growth and propagation of intracellular T. gondii in human fibroblasts and in ovine monocytic cells.

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

    USGS Publications Warehouse

    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.

  13. Seroprevalence, Isolation, Genotyping, and Pathogenicity of Toxoplasma gondii Strains from Sheep in China.

    PubMed

    Yang, YuRong; Feng, YongJie; Yao, QiuXia; Wang, YingHua; Lu, YaoYao; Liang, HongDe; Zhu, XingQuan; Zhang, LongXian

    2017-01-01

    Toxoplasma gondii is an important cause of reproductive failure in small ruminants that also poses a risk to consumers who consume undercooked meat. However, little is known about sheep toxoplasmosis in China for the world. Therefore, this study was conducted to assess the prevalence of T. gondii infection in sheep from China, to isolate T. gondii via bioassay in mice and to evaluate the virulence of the isolated T. gondii based on vero cell invasion and mice. A total of 840 samples (304 unfrozen hearts and 536 sera) from sheep in China were collected from 2014 to 2016. Heart samples (n = 36) of T. gondii seropositive sheep (MAT, ≥25) were bioassayed in mice individually. DNA derived from cell cultured tachyzoites of the isolated T. gondii was characterized by PCR-RFLP of 10 loci (SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico). The virulence of the T. gondii was evaluated based on the mortality and encystation in mice, as well as their growth characteristics in cell culture. Antibodies to T. gondii were found in 174 of 840 (20.71%, 304 hearts juice and 536 sera) sheep by the modified agglutination test (cut-off 1:25). Viable T. gondii was isolated from the hearts of two of 36 seropositive sheep hearts. Both genotypes of the sheep heart isolates were ToxoDB#9. The virulence of the two ToxoDB#9 isolations varied significantly. To the best of our knowledge, this is the first report of isolation of ToxoDB#9 strain of T. gondii from sheep in China.

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

    PubMed

    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.

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

    PubMed Central

    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

    2016-01-01

    Objectives We determined the seroprevalence and correlates of Toxoplasma gondii infection in pregnant women in Aguascalientes City, Mexico. Design A cross-sectional survey. Setting Pregnant women were enrolled in the central Mexican city of Aguascalientes. Participants We studied 338 pregnant women who attended prenatal care in 3 public health centres. Primary and secondary outcome measures 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. Results 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; p<0.01), not washing hands before eating (OR=6.41; 95% CI 1.73 to 23.6; p=0.005) and use of latrine (OR=37.6; 95% CI 4.63 to 306.31; p=0.001). Conclusions Results demonstrate that pregnant women in Aguascalientes City have a low seroprevalence of T. gondii infection. However, this low prevalence indicates that most pregnant women are at risk for a primary 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. PMID:27371556

  16. Seroprevalence, Isolation, Genotyping, and Pathogenicity of Toxoplasma gondii Strains from Sheep in China

    PubMed Central

    Yang, YuRong; Feng, YongJie; Yao, QiuXia; Wang, YingHua; Lu, YaoYao; Liang, HongDe; Zhu, XingQuan; Zhang, LongXian

    2017-01-01

    Toxoplasma gondii is an important cause of reproductive failure in small ruminants that also poses a risk to consumers who consume undercooked meat. However, little is known about sheep toxoplasmosis in China for the world. Therefore, this study was conducted to assess the prevalence of T. gondii infection in sheep from China, to isolate T. gondii via bioassay in mice and to evaluate the virulence of the isolated T. gondii based on vero cell invasion and mice. A total of 840 samples (304 unfrozen hearts and 536 sera) from sheep in China were collected from 2014 to 2016. Heart samples (n = 36) of T. gondii seropositive sheep (MAT, ≥25) were bioassayed in mice individually. DNA derived from cell cultured tachyzoites of the isolated T. gondii was characterized by PCR-RFLP of 10 loci (SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico). The virulence of the T. gondii was evaluated based on the mortality and encystation in mice, as well as their growth characteristics in cell culture. Antibodies to T. gondii were found in 174 of 840 (20.71%, 304 hearts juice and 536 sera) sheep by the modified agglutination test (cut-off 1:25). Viable T. gondii was isolated from the hearts of two of 36 seropositive sheep hearts. Both genotypes of the sheep heart isolates were ToxoDB#9. The virulence of the two ToxoDB#9 isolations varied significantly. To the best of our knowledge, this is the first report of isolation of ToxoDB#9 strain of T. gondii from sheep in China. PMID:28217119

  17. Molecular and biological characteristics of Toxoplasma gondii isolates from wildlife in France.

    PubMed

    Aubert, D; Ajzenberg, D; Richomme, C; Gilot-Fromont, E; Terrier, M E; de Gevigney, C; Game, Y; Maillard, D; Gibert, P; Dardé, M L; Villena, I

    2010-08-04

    Toxoplasma gondii isolates have been classified into 3 genetic types. Little is known about genotypes of T. gondii isolates in wild animals in Europe. In this report, genotypes of T. gondii isolates from wildlife in France are described. Sera from wildlife were tested for antibodies to T. gondii with the modified agglutination test, and the hearts from animals with titers superior or equal to 1:6 were bioassayed individually in mice. T.gondii was isolated from 9 of 14 seropositive red foxes (Vulpes vulpes), 12 of 33 roe deer (Capreolus capreolus), 1 of 4 deer (Cervus elaphus), 1 of 7 mouflons (Ovis gmelini musimon) and 1 of 2 common mallards (Anas platyrhynchos). No isolate was obtained by bioassay in mice of 1 fallow deer (Dama dama) and of 3 European brown hares (Lepus europaeus). Genotyping of the 24 isolates using PCR-RFLP and microsatellite markers indicated that all were type II and none of these Toxoplasma isolates was virulent for mice.

  18. A field trial of the effectiveness of a feline Toxoplasma gondii vaccine in reducing T. gondii exposure for swine.

    PubMed

    Mateus-Pinilla, N E; Dubey, J P; Choromanski, L; Weigel, R M

    1999-10-01

    A 3-yr field trial was conducted on 8 commercial swine farms in Illinois to determine the effectiveness of a feline Toxoplasma gondii vaccine in reducing the exposure of swine to T. gondii. A vaccine consisting of live bradyzoites of the mutant T-263 strain, capable of preventing oocyst shedding by cats, was used in this study. Each farm was visited 3 times in 1994, 3 times in 1995, and once in 1996. Cats were trapped and inoculated with the T-263 oral vaccine during 1994 and 1995. On each visit, the following samples were collected: blood from pigs, cats, and mice for detection of serum antibodies to T. gondii, feces from cats to detect oocysts, and heart and brain tissues from rodents to determine the presence of T. gondii tissue cysts. The modified agglutination test (MAT), with a positive titer set at the 1:25 dilution, was used to determine serum antibodies. At first capture, 72.6% (61/84) of juvenile cats and 32.6% (31/95) of adult cats had no detectable antibodies (seronegative), indicating no prior exposure to T. gondii when they received their first vaccine. Of these first-time seronegative cats, 58.1% (18/31) of adult and 45.9% (28/61) of juvenile cats were recaptured and received a second dose of vaccine. Changes in the prevalence of T. gondii infection were evaluated from the prevaccination (1992, 1993) to the postvaccination (1996) period. Eleven cats (5%) were detected shedding oocysts between 1994 and 1996, of which 10 (90.1%) shed during 1994. The last detection of oocyst shedding by cats was during the first farm visit in 1995. There was a significant decrease in T. gondii seroprevalence for finishing pigs (P < 0.05, Wilcoxon sign rank test). There was a positive correlation (Spearman's p = 1.0, P < 0.0001) between the change in prevalence in juvenile cats and the change in prevalence in finishing pigs. The seropositivity rate (MAT > or = 1:25) in mice among all farms decreased from 4% in 1992-1993 to 0% in 1996. The mean prevalence of T. gondii

  19. THE OPPORTUNISTIC PATHOGEN TOXOPLASMA GONDII DEPLOYS A DIVERSE LEGION OF INVASION AND SURVIVAL PROTEINS

    PubMed Central

    Zhou, Xing W.; Kafsack, Björn F. C.; Cole, Robert N.; Beckett, Phil; Shen, Rong F.; Carruthers, Vern B.

    2006-01-01

    Host cell invasion is an essential step during infection by Toxoplasma gondii, an intracellular protozoan that causes the severe opportunistic disease toxoplasmosis in humans. Recent evidence strongly suggests that proteins discharged from Toxoplasma apical secretory organelles (micronemes, dense granules, and rhoptries) play key roles in host cell invasion and survival during infection. However, to date, only a limited number of secretory proteins have been discovered and the full spectrum of effector molecules involved in parasite invasion and survival remains unknown. To address these issues, we analyzed a large cohort of freely released Toxoplasma secretory proteins using two complementary methodologies, 2-DE/MS and LC/ESI-MS-MS (MudPIT, shotgun proteomics). Visualization of Toxoplasma secretory products by 2-DE revealed ∼100 spots, most of which were successfully identified by protein microsequencing or MALDI-MS analysis. Many proteins were present in multiple species suggesting they are subjected to substantial posttranslational modification. Shotgun proteomic analysis of the secretory fraction revealed several additional products including novel putative adhesive proteins, proteases, and hypothetical secretory proteins similar to products expressed by other related parasites including Plasmodium, the etiologic agent of malaria. A subset of novel proteins were re-expressed as fusions to yellow fluorescent protein and this initial screen revealed shared and distinct localizations within secretory compartments of T. gondii tachyzoites. The findings provide a uniquely broad view of Toxoplasma secretory proteins that participate in parasite survival and pathogenesis during infection. PMID:16002397

  20. Seroprevalence of Toxoplasma gondii infection among patients with non-schizophrenic neurodevelopmental disorders in Alexandria, Egypt.

    PubMed

    Shehata, Amany I; Hassanein, Faika I; Abdul-Ghani, Rashad

    2016-02-01

    Toxoplasma gondii is an opportunistic parasite with neurotropic characteristics that can mediate neurodevelopmental disorders, including mental, behavioral and personality aspects of their hosts. Therefore, the seroprevalence of anti-Toxoplasma antibodies has been studied in patients with different neurological disorders from different localities. On searching online databases, however, we could not find published studies on the seroprevalence of anti-Toxoplasma antibodies among patients with neurodevelopmental disorders in Egypt. Therefore, the present preliminary study was conducted to determine the serological profile of T. gondii infection among patients with non-schizophrenic neurodevelopmental disorders in Alexandria, Egypt. Data and blood samples were collected from 188 patients recruited for the study from four mental rehabilitation centers in the period from July 2014 to March 2015. The overall seropositivity rates of IgM and IgG among patients were 16.5% (31/188) and 50.0% (94/188), respectively. Of the studied patients' characteristics, only age was significantly associated with anti-Toxoplasma IgG seropositivity, with older patients being about twice more likely exposed to infection. However, no statistically significant association was found with IgM. In addition, seropositivity of anti-Toxoplasma IgG, but not IgM, was significantly associated with non-schizophrenic neurodevelopmental disorders; however, neither IgG nor IgM showed a significant association with cognitive impairment as indicated by the intelligence quotient scores.

  1. The HU Protein Is Important for Apicoplast Genome Maintenance and Inheritance in Toxoplasma gondii

    PubMed Central

    Reiff, Sarah B.; Vaishnava, Shipra

    2012-01-01

    The apicoplast, a chloroplast-like organelle, is an essential cellular component of most apicomplexan parasites, including Plasmodium and Toxoplasma. The apicoplast maintains its own genome, a 35-kb DNA molecule that largely encodes proteins required for organellar transcription and translation. Interference with apicoplast genome maintenance and function is a validated target for drug therapy for malaria and toxoplasmosis. However, the many proteins required for genome maintenance and inheritance remain largely unstudied. Here we genetically characterize a nucleus-encoded homolog to the bacterial HU protein in Toxoplasma gondii. In bacteria, HU is a DNA-binding structural protein with fundamental roles in transcription, replication initiation, and DNA repair. Immunofluorescence assays reveal that in T. gondii this protein localizes to the apicoplast. We have found that the HU protein from Toxoplasma can successfully complement bacterial ΔhupA mutants, supporting a similar function. We were able to construct a genetic knockout of HU in Toxoplasma. This Δhu mutant is barely viable and exhibits significant growth retardation. Upon further analysis of the mutant phenotype, we find that this mutant has a dramatically reduced apicoplast genome copy number and, furthermore, suffers defects in the segregation of the apicoplast organelle. Our findings not only show that the HU protein is important for Toxoplasma cell biology but also demonstrate the importance of the apicoplast genome in the biogenesis of the organelle. PMID:22611021

  2. Seroprevalence of Toxoplasma gondii antibodies in the rodent capybara (Hidrochoeris hidrochoeris) from Brazil.

    PubMed

    Cañon-Franco, W A; Yai, L E O; Joppert, A M; Souza, C E; D'Auria, S R N; Dubey, J P; Gennari, S M

    2003-08-01

    Capybaras (Hidrochoeris hidrochoeris) are 1 of the largest rodents used for meat in South and Central America. Prevalence of anti-Toxoplasma gondii antibodies in 149 feral H. hidrochoeris from the state of São Paulo, Brazil, was evaluated using the indirect immunofluorescent antibody test (IFAT) and the modified agglutination test (MAT). Using IFAT, antibodies (>1:16) were found in 104 (69.8%) and with the MAT, antibodies (>1:25) were found in 63 (42.3%) capybaras. This is the first report of prevalence of T. gondii antibodies in this host.

  3. Prevalence of Toxoplasma gondii antibodies and the relation to risk factors in cats of Colima, Mexico.

    PubMed

    García-Márquez, Luis Jorge; Gutiérrez-Díaz, Miguel Angel; Correa, Dolores; Luna-Pastén, Héctor; Palma, José Manuel

    2007-12-01

    The prevalence of Toxoplasma gondii antibodies in 80 domestic cats was studied in the city of Colima, Mexico, using an indirect IgG-ELISA. Antibodies were found in 28.8% of the cats, with significantly higher (P = 0.029) prevalence in southern and central zones (33.8%) than the northern zone (6.6%). Prevalence among cats fed with homemade food was higher than those eating commercial pellets (40.6% [vs.] 20.8%; P = 0.055). Overall, the prevalence of T. gondii antibodies in the cats of Colima was lower than in many other countries.

  4. Toxoplasma gondii infection, from predation to schizophrenia: can animal behaviour help us understand human behaviour?

    PubMed Central

    Webster, Joanne P.; Kaushik, Maya; Bristow, Greg C.; McConkey, Glenn A.

    2013-01-01

    Summary We examine the role of the protozoan Toxoplasma gondii as a manipulatory parasite and question what role study of infections in its natural intermediate rodent hosts and other secondary hosts, including humans, may elucidate in terms of the epidemiology, evolution and clinical applications of infection. In particular, we focus on the potential association between T. gondii and schizophrenia. We introduce the novel term ‘T. gondii–rat manipulation–schizophrenia model’ and propose how future behavioural research on this model should be performed from a biological, clinical and ethically appropriate perspective. PMID:23225872

  5. Toxoplasma gondii: immunogenicity and protection by P30 peptides in a murine model.

    PubMed

    Siachoque, Heber; Guzman, Fanny; Burgos, Javier; Patarroyo, Manuel Elkin; Gomez Marin, Jorge Enrique

    2006-09-01

    Vaccines are promising for the control of toxoplasmosis. Here, we evaluated the immunogenicity of 17 peptides derived from SAG1 surface protein of Toxoplasma gondii in CH3 mice. Only 8 of 16 peptides induced specific antibodies. After a lethal challenge, only the vaccination with 4 of 17 peptides that were from the carboxy terminal end of the protein conferred significant survival. Our work shows that vaccination with peptides from the carboxy-terminal positions of SAG1 major surface protein of Toxoplasma protects mice against a lethal challenge.

  6. Autophagy-Related Protein ATG8 Has a Noncanonical Function for Apicoplast Inheritance in Toxoplasma gondii

    PubMed Central

    Lévêque, Maude F.; Berry, Laurence; Cipriano, Michael J.; Nguyen, Hoa-Mai; Striepen, Boris

    2015-01-01

    ABSTRACT Autophagy is a catabolic process widely conserved among eukaryotes that permits the rapid degradation of unwanted proteins and organelles through the lysosomal pathway. This mechanism involves the formation of a double-membrane structure called the autophagosome that sequesters cellular components to be degraded. To orchestrate this process, yeasts and animals rely on a conserved set of autophagy-related proteins (ATGs). Key among these factors is ATG8, a cytoplasmic protein that is recruited to nascent autophagosomal membranes upon the induction of autophagy. Toxoplasma gondii is a potentially harmful human pathogen in which only a subset of ATGs appears to be present. Although this eukaryotic parasite seems able to generate autophagosomes upon stresses such as nutrient starvation, the full functionality and biological relevance of a canonical autophagy pathway are as yet unclear. Intriguingly, in T. gondii, ATG8 localizes to the apicoplast under normal intracellular growth conditions. The apicoplast is a nonphotosynthetic plastid enclosed by four membranes resulting from a secondary endosymbiosis. Using superresolution microscopy and biochemical techniques, we show that TgATG8 localizes to the outermost membrane of this organelle. We investigated the unusual function of TgATG8 at the apicoplast by generating a conditional knockdown mutant. Depletion of TgATG8 led to rapid loss of the organelle and subsequent intracellular replication defects, indicating that the protein is essential for maintaining apicoplast homeostasis and thus for survival of the tachyzoite stage. More precisely, loss of TgATG8 led to abnormal segregation of the apicoplast into the progeny because of a loss of physical interactions of the organelle with the centrosomes. PMID:26507233

  7. Toxoplasma gondii infection among sheep and goats in Iran: a systematic review and meta-analysis.

    PubMed

    Sharif, M; Sarvi, Sh; Shokri, A; Hosseini Teshnizi, S; Rahimi, M T; Mizani, A; Ahmadpour, E; Daryani, A

    2015-01-01

    Toxoplasmosis, a cosmopolitan parasitic infection caused by Toxoplasma gondii, is frequently found in meat-producing animals and human beings. This review and meta-analysis study was performed to evaluate the overall prevalence of T. gondii infection among sheep and goats in Iran. Data were systematically collected from 1977 to 2012 in Iran on the following electronic databases: PubMed, Google Scholar, Science Direct, Scopus, Web of Science, Magiran, Irandoc, IranMedex, and Scientific Information Database (SID). Additionally, abstracts of national scientific congresses and dissertations were included. A total of 34 articles in field of sheep and 18 articles about goat toxoplasmosis, totalizing to the examination of 14,372 sheep and 3,120 goats, reporting prevalence of toxoplasmosis from different regions of Iran fulfilled our eligibility criteria. The overall prevalence rate of toxoplasmosis in Iran was estimated to be 31% (95% confidence interval (CI) = 0.259825 to 0.352382) in sheep and 27% (95% CI = 0.140097 to 0.424782) in goats, respectively. There was no significant difference in infection rate between males and females among sheep (odds ratio (OR) = 1.002, 95% CI = 0.59 to 1.696) and goats (OR = 1.027, 95% CI = 0.685 to 1.541). Analysis revealed that infection rate in sheep over than 1 year old was 2.4 times more than that in less than 1 year old (OR = 2.396, 95% CI = 1.050 to 5.467). This systematic review and meta-analysis study revealed that infection is widespread in Iran. Further studies are required to improve strategies for controlling infection among flocks and consequently in human population.

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

    PubMed Central

    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

  9. Clonal types of Toxoplasma gondii among immune compromised and immune competent individuals in Accra, Ghana.

    PubMed

    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.

  10. High Seroprevalence of Toxoplasma Gondii Infection in Female Sex Workers: A Case-Control Study

    PubMed Central

    Alvarado-Esquivel, Cosme; Sánchez-Anguiano, Luis Francisco; Hernández-Tinoco, Jesús; Arreola-Cháidez, Emilio; López, Juan; Salcido-Meraz, Karla Itzel; Estrada-Martínez, Sergio; Navarrete-Flores, José Antonio; Pérez-Álamos, Alma Rosa; Hernández-Ochoa, Marcia; Rábago-Sánchez, Elizabeth; Liesenfeld, Oliver

    2015-01-01

    Through an age- and sex-matched case-control study, we sought to determine whether female sex workers have an increased risk of Toxoplasma gondii exposure and to determine the sociodemographic, work, clinical, and behavioral characteristics of these workers associated with T. gondii exposure. Female workers (n = 136) and controls (n = 272) were examined with enzyme-linked immunoassays (EIA) for the presence of anti-Toxoplasma IgG and IgM antibodies. IgM positive sera were additionally tested with enzyme linked-fluorescence immunoassay (ELFA). Anti-T. gondii IgG antibodies were found in 21 (15.44%) of 136 cases and in 10 (3.67%) of 272 controls (OR = 4.05; 95% CI: 1.84–8.89; P = 0.0001). Anti-T. gondii IgG levels higher than 150 IU/ml were found in 13 (9.6%) of 136 cases and in 8 (2.9%) of 272 controls (P = 0.007). Anti-T. gondii IgM antibodies were found in two cases and in six controls by EIA, but all were negative by ELFA. T. gondii seropositivity was associated with being born out of Durango State (OR = 10.47; 95% CI: 2.9–36.8; P < 0.01), injuries during sex work (OR = 6.30; 95% CI: 1.1–33.7; P = 0.03), and soil contact (OR = 4.11; 95% CI: 1.2–14.0; P = 0.02). This is the first report of an association of T. gondii infection and female sex workers. PMID:26716017

  11. Mouse-virulent Toxoplasma gondii isolated from feral cats on Mona Island, Puerto Rico.

    PubMed

    Dubey, J P; López-Torres, H Y; Sundar, N; Velmurugan, G V; Ajzenberg, D; Kwok, O C H; Hill, R; Dardé, M L; Su, C

    2007-12-01

    Cats are essential in the life cycle of Toxoplasma gondii because they are the only hosts that can excrete the environmentally resistant oocysts. Samples of serum, feces, and tissues from cats from Mona, a remote island off the coast of Puerto Rico, were examined for T. gondii infection. Antibodies to T. gondii were assayed by the modified agglutination test and found in 16 of 19 (84.2%) of cats, with titers of 1:10 in 2, 1:80 in 1, 1:160 in 4, 1:320 in 3, and 1:1,280 or higher in 6. Tissues of 19 of the 20 cats were bioassayed in mice for T. gondii infection. Toxoplasma gondii was isolated from tissues of 12 cats: from the hearts of 9, skeletal muscle of 10, and brain of 1 cat. All infected mice from 10 of 12 isolates died of acute toxoplasmosis during primary infection. Genotyping of these 12 T. gondii isolates (designated (TgCatPr 1-12) by 10 multilocus PCR-RFLP markers, i.e., SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and an apicoplast marker Apico, and the 6 multilocus microsatellite markers TUB2, W35, TgM-A, B18, B17, and M33, revealed 7 genotypes; 5 isolates had Type I alleles at all loci except at 1 microsatellite locus, and the remainder were atypical. The latter isolates of T. gondii were different biologically and phenotypically from the feline isolates from the rest of the Americas. One isolate (TgCatPr 12) was a mixed infection with 2 genotypes.

  12. Prevalence and genotyping ofToxoplasma gondii among Saudi pregnant women in Saudi Arabia.

    PubMed

    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.

  13. TgPRELID, a Mitochondrial Protein Linked to Multidrug Resistance in the Parasite Toxoplasma gondii

    PubMed Central

    Kamau, Edwin T.; Srinivasan, Ananth R.; Harper, Jonathan; Sankaran, Preethi; Post, Sarah E.; Varberg, Joseph M.

    2017-01-01

    ABSTRACT New drugs to control infection with the protozoan parasite Toxoplasma gondii are needed as current treatments exert toxic side effects on patients. Approaches to develop novel compounds for drug development include screening of compound libraries and targeted inhibition of essential cellular pathways. We identified two distinct compounds that display inhibitory activity against the parasite’s replicative stage: F3215-0002, which we previously identified during a compound library screen, and I-BET151, an inhibitor of bromodomains, the “reader” module of acetylated lysines. In independent studies, we sought to determine the targets of these two compounds using forward genetics, generating resistant mutants and identifying the determinants of resistance with comparative genome sequencing. Despite the dissimilarity of the two compounds, we recovered resistant mutants with nonsynonymous mutations in the same domain of the same gene, TGGT1_254250, which we found encodes a protein that localizes to the parasite mitochondrion (designated TgPRELID after the name of said domain). We found that mutants selected with one compound were cross resistant to the other compound, suggesting a common mechanism of resistance. To further support our hypothesis that TgPRELID mutations facilitate resistance to both I-BET151 and F3215-0002, CRISPR (clustered regularly interspaced short palindromic repeat)/CAS9-mediated mutation of TgPRELID directly led to increased F3215-0002 resistance. Finally, all resistance mutations clustered in the same subdomain of TgPRELID. These findings suggest that TgPRELID may encode a multidrug resistance factor or that I-BET151 and F3215-0002 have the same target(s) despite their distinct chemical structures. IMPORTANCE We report the discovery of TgPRELID, a previously uncharacterized mitochondrial protein linked to multidrug resistance in the parasite Toxoplasma gondii. Drug resistance remains a major problem in the battle against parasitic

  14. Toxoplasma gondii AP2IX-4 Regulates Gene Expression during Bradyzoite Development

    PubMed Central

    Huang, Sherri; Holmes, Michael J.; Radke, Joshua B.; Hong, Dong-Pyo; Liu, Ting-Kai; White, Michael W.

    2017-01-01

    ABSTRACT Toxoplasma gondii is a protozoan parasite of great importance to human and animal health. In the host, this obligate intracellular parasite persists as a tissue cyst that is imperceptible to the immune response and unaffected by current therapies. The tissue cysts facilitate transmission through predation and give rise to chronic cycles of toxoplasmosis in immunocompromised patients. Transcriptional changes accompany conversion of the rapidly replicating tachyzoites into the encysted bradyzoites, and yet the mechanisms underlying these alterations in gene expression are not well defined. Here we show that AP2IX-4 is a nuclear protein exclusively expressed in tachyzoites and bradyzoites undergoing division. Knockout of AP2IX-4 had no discernible effect on tachyzoite replication but resulted in a reduced frequency of tissue cyst formation following alkaline stress induction—a defect that is reversible by complementation. AP2IX-4 has a complex role in regulating bradyzoite gene expression, as the levels of many bradyzoite mRNAs dramatically increased beyond those seen under conditions of normal stress induction in AP2IX-4 knockout parasites exposed to alkaline media. The loss of AP2IX-4 also resulted in a modest virulence defect and reduced cyst burden in chronically infected mice, which was reversed by complementation. These findings illustrate that the transcriptional mechanisms responsible for tissue cyst development operate across the intermediate life cycle from the dividing tachyzoite to the dormant bradyzoite. IMPORTANCE Toxoplasma gondii is a single-celled parasite that persists in its host as a transmissible tissue cyst. How the parasite converts from its replicative form to the bradyzoites housed in tissue cysts is not well understood, but the process clearly involves changes in gene expression. Here we report that parasites lacking a cell cycle-regulated transcription factor called AP2IX-4 display reduced frequencies of tissue cyst formation in

  15. Seroprevalence of Toxoplasma gondii in slaughtered horses and donkeys in Liaoning province, northeastern China

    PubMed Central

    2013-01-01

    Background Toxoplasma gondii is an important zoonotic pathogen infecting humans and almost all warm-blooded animals. The most common sources of human infection are ingestion of tissue cysts in raw or undercooked meat. However, limited information is available about T. gondii infection in horses and donkeys in China. In the present study, we report the seroprevalence of T. gondii infection in horses and donkeys in Liaoning province, northeastern China. Methods Serum samples were collected from 711 and 738 slaughtered horses and donkeys, respectively, in 13 regions of Liaoning province. The modified agglutination test (MAT) was used to test the specific antibodies to T. gondii. Results In this study, 178 of 711 (25.0%) horses were seropositive for T. gondii with titers of 1:25 in 81, 1:50 in 62, 1:100 in 33, and 1:200 in 2, and seroprevalence of T. gondii infection from 13 regions ranged from 8.2% to 37.0%. Antibodies to T. gondii were found in 174 of 738 (23.6%) donkeys with titers of 1:25 in 66, 1:50 in 54, 1:100 in 49, and 1:200 in 5, and seroprevalence varied in 13 different regions, ranging from 9.1% to 32.6%. Conclusions The results of the present study indicated that the rate of infection with T. gondii in horses and donkeys is a little high in Liaoning province, northeastern China in comparison to other surveys in China, which suggests that consumption of horse and donkey meat in this area may represent a potential source for human infection with T. gondii. PMID:23680297

  16. Soil contamination of Toxoplasma gondii oocysts in pig farms in central China.

    PubMed

    Du, Fen; Zhang, Qingli; Yu, Qian; Hu, Min; Zhou, Yanqin; Zhao, Junlong

    2012-06-08

    Toxoplasmosis in pigs is a large threat to pig industry as well as pork consumers. Most pigs become infected by ingestion of oocysts from contaminated environment (soil, water and feed) or infected animal tissues postnatally. In the present study, field studies were conducted to evaluate the relationship between soil contamination status of Toxoplasma gondii oocysts and T. gondii infection in pigs in 12 pig farms with different density of cats in central China. The presence of T. gondii oocysts in soil were determined by PCR and loop-mediated isothermal amplification (LAMP). T. gondii DNA was found in 11 farms with different cat density excepting one farm exposed to low cat density. Twenty (21.1%) and 36 (37.9%) of 95 soil samples were T. gondii positive by PCR and LAMP, respectively (0.01gondii using AG-ELISA. Antibodies were found in 453 of 1238 (36.6%) samples from pig farms with high cat density and 220 of 1039 (21.2%) samples from pig farms with low cat density (P<0.01). The results indicated that a high seroprevalence of T. gondii in pigs was found in the pig farms with high soil contamination by T. gondii oocysts in Hubei Province. The soil contamination status of pig farms was significantly influenced by cat density and may be an indicator of T. gondii infection in pigs.

  17. Involvement of Toxoplasma gondii in reproductive disorders in Swiss pig farms.

    PubMed

    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.

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

    PubMed Central

    Cabezón, Oscar; Cerdà-Cuéllar, Marta; Morera, Virginia; García-Bocanegra, Ignacio; González-Solís, Jacob; Napp, Sebastian; Ribas, Maria P.; Blanch-Lázaro, Berta; Fernández-Aguilar, Xavier; Antilles, Noelia; López-Soria, Sergio; Lorca-Oró, Cristina; Dubey, Jitender P.; Almería, Sonia

    2016-01-01

    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. PMID:26974667

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

    PubMed

    Cabezón, Oscar; Cerdà-Cuéllar, Marta; Morera, Virginia; García-Bocanegra, Ignacio; González-Solís, Jacob; Napp, Sebastian; Ribas, Maria P; Blanch-Lázaro, Berta; Fernández-Aguilar, Xavier; Antilles, Noelia; López-Soria, Sergio; Lorca-Oró, Cristina; Dubey, Jitender P; Almería, Sonia

    2016-01-01

    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.

  20. High seroprevalence of Toxoplasma gondii infection in inmates: A case control study in Durango City, Mexico

    PubMed Central

    Hernández-Tinoco, J.; Sánchez-Anguiano, L. F.; Ramos-Nevárez, A.; Cerrillo-Soto, S. M.; Sáenz-Soto, L.; Liesenfeld, O.

    2014-01-01

    Purpose The seroprevalence of infection with the parasite Toxoplasma gondii and the association with risk factors has not been determined in inmates. Through a case-control study, 166 inmates from a state correctional facility in Durango City, Mexico and 166 age- and gender-matched non-incarcerated subjects were examined for the presence of anti-T. gondii IgG and IgM antibodies using enzyme-linked immunoassays. Results Seroprevalence of anti-T. gondii IgG antibodies was higher in inmates (35, 21.1%) than in controls (14, 8.4%) (OR = 2.90; 95% CI: 1.43–5.94; P = 0.001). Anti-T. gondii IgM antibodies were detected in two (1.2%) inmates and in seven (4.2%) controls (P = 0.17). Multivariate analysis of socio-demographic, incarceration, and behavioral characteristics of inmates revealed that T. gondii seropositivity was associated with being born out of Durango State (OR = 3.91; 95% CI: 1.29–11.79; P = 0.01). In addition, T. gondii seroprevalence was higher (P = 0.03) in inmates that had suffered from injuries (17/56: 30.4%) than those without such history (18/110: 16.4%). Conclusions The seroprevalence of T. gondii infection in inmates in Durango City is higher than the seroprevalences found in the general population in the same city, indicating that inmates may represent a new risk group for T. gondii infection. Further research on T. gondii infection in inmates is needed. PMID:24678408

  1. Toxoplasma gondii infection and cerebral toxoplasmosis in HIV-infected patients.

    PubMed

    Pereira-Chioccola, Vera Lucia; Vidal, José Ernesto; Su, Chunlei

    2009-12-01

    Cerebral toxoplasmosis is a major cause of morbidity and mortality among HIV-infected patients, particularly from developing countries. This article summarizes current literature on cerebral toxoplasmosis. It focuses on: Toxoplasma gondii genetic diversity and its possible relationship with disease presentation; host responses to the parasite antigens; host immunosupression in HIV and cerebral toxoplasmosis as well as different diagnostic methods; clinical and radiological features; treatment; and the direction that studies on cerebral toxoplasmosis will likely take in the future.

  2. Elevated Toxoplasma gondii Infection Rates for Retinas from Eye Banks, Southern Brazil.

    PubMed

    Commodaro, Alessandra G; Chiasson, Melissa; Sundar, Natarajan; Rizzo, Luiz Vicente; Belfort, Rubens; Grigg, Michael E

    2016-04-01

    We found significantly higher incidence of Toxoplasma gondii DNA in eye bank specimens from Joinville in southern Brazil (13/15, 87%) than in São Paulo (3/42, 7%; p = 2.1 × 10E-8). PCR DNA sequence analysis was more sensitive at locus NTS2 than at locus B1; a high frequency of mixed co-infections was detected.

  3. Seroprevalence of Toxoplasma Gondii antibodies in cats from Durango City, Mexico.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The prevalence of antibodies to Toxoplasma gondii was determined in sera from 105 domestic cats from Durango City, Mexico. Using a modified agglutination test, antibodies to this parasite were found in (21%) of the 105 cats with titers of 1:25 in 3, 1:50 in 4, 1:200 in 5, 1:400 in 2, 1:800 in 2, 1...

  4. Seroprevalence of toxoplasma gondii in cats from Sr. Kitts, West Indies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The prevalence of antibodies to Toxoplasma gondii was determined in sera from 106 domestic cats from St. Kitts, West Indies. Using a modified agglutination test, antibodies to this parasite were found in 90 (84.9%) of the cats with titers of 1:20 in 23, 1:40 in 34, 1:80 in 18, 1:160 in 2, 1:32...

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

    EPA Science Inventory

    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...

  6. Factors affecting seroprevalence of Toxoplasma gondii in the endangered Iberian lynx (Lynx pardinus).

    PubMed

    García-Bocanegra, I; Dubey, J P; Martínez, F; Vargas, A; Cabezón, O; Zorrilla, I; Arenas, A; Almería, S

    2010-01-20

    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 (Lynx pardinus) is the most endangered felid species in the world. In the present study, seroprevalence and associated risk factors for T. gondii infection in a large population of Iberian lynx in Spain were determined. Serum samples from 129 Iberian lynx collected from 2005 to 2009 and 85 wild rabbits (Oryctolagus cuniculus), sharing the habitat with the Iberian lynx, were tested for antibodies to T. gondii by the modified agglutination test (MAT) using a cut-off value of 1:25. Antibodies to T. gondii were found in 81 of 129 (62.8%) Iberian lynx. Seroprevalence to T. gondii in Iberian lynx significantly increased with age (P<0.001). T. gondii seroprevalences were similar in free-ranging (66.7% of 93) and wild-caught captive lynx (69% of 84) but significantly lower in captive-born lynx (22.5% of 40). Seroprevalence was higher in lynx with concurrent Cytauxzoonfelis (88% of 25) but not with concurrent Feline Leukemia Virus (FeLV) infection (53.8% of 13). There were no significant differences in seroprevalence between sexes, geographic region and year of sample collection (2005-2009). Oocysts of T. gondii were not detected microscopically in fecal samples from 58 lynx. Wild rabbits are considered the most important food for the lynx. Antibodies to T. gondii were found in 14 (11.9%) of 85 rabbits tested. The present results indicate that T. gondii infection is widespread in the two areas where Iberian lynx survive in Spain. The fact that four captive-born lynx seroconverted was indication of contact with T. gondii also in the Captive Breeding Centers, hence, control measures to prevent T. gondii infection would be necessary in these centers.

  7. Coinfection of Leptospira spp and Toxoplasma gondii among stray dogs in Bangkok, Thailand.

    PubMed

    Jittapalapong, Sathaporn; Sittisan, Patsima; Sakpuaram, Thavajchai; Kabeya, Hidenori; Maruyama, Soichi; Inpankaew, Tawin

    2009-03-01

    Leptospirosis and toxoplasmosis are zoonotic diseases with global importance. Asymptomatic animals harboring these pathogens may act as carriers to other animals including humans. The objective of this study was to investigate the seroprevalence of Leptospira and Toxoplasma infections in stray dogs in Bangkok. A total of 230 stray dogs from monasteries in a Bangkok district were examined for specific antibodies to T. gondii and Leptospira. The seroprevalence of T. gondii was determined by a modified latex agglutination test (cut off 1 > or = 64). A microscopic agglutination test was performed to detect antibodies to Leptospira (cut off, 1:100). The seroprevalences of T. gondii and Leptospira were 10.9% (25/ 230) and 83.5% (192/230), respectively. Leptospira serovar bataviae was the most predominant (20.3%) serovar. Co-infection with Leptospira and Toxoplasma was found in 22 dogs (9.6%). The prevalence of Toxoplasma in females was significantly higher than in males (p < 0.05), but no significant differences was observed for Leptospira. The high seroprevalence of these two diseases in dogs is of public health concern because close contact between dogs and humans may provide a link between a reservoir in the environment and susceptible humans.

  8. Serological evidence of Toxoplasma gondii infection in captive marine mammals in Mexico.

    PubMed

    Alvarado-Esquivel, C; Sánchez-Okrucky, R; Dubey, J P

    2012-03-23

    Toxoplasma gondii infection in marine mammals is important because they are considered as a sentinel for contamination of seas with T. gondii oocysts, and toxoplasmosis causes mortality in these animals, particularly sea otters. Serological evidence of T. gondii infection was determined in 75 captive marine mammals from four facilities in southern and central geographical regions in Mexico using the modified agglutination test (MAT). Antibodies (MAT, 1:25 or higher) to T. gondii were found in 55 (87.3%) of 63 Atlantic bottlenose dolphins (Tursiops truncatus truncatus), 3 of 3 Pacific bottlenose dolphins (Tursiops truncatus gillii), 2 of 4 California sea lions (Zalophus californianus), but not in 3 West Indian manatees (Trichechus manatus), and 2 Patagonian sea lions (Otaria flavescens). Seropositive marine mammals were found in all 4 (100%) facilities sampled. All marine mammals were healthy and there has not been any case of clinical toxoplasmosis in the facilities sampled for at least the last 15 years. The seroprevalence of T. gondii infection in marine mammals of the same species did not vary significantly with respect to sex and age. This is the first report on the detection of antibodies to T. gondii in marine mammals in Mexico.

  9. Is Toxoplasma gondii a threat to the conservation of free-ranging Australian marsupial populations?

    PubMed

    Hillman, Alison E; Lymbery, Alan J; Thompson, R C Andrew

    2016-04-01

    It has often been asserted that Australian marsupial species are particularly susceptible to Toxoplasma gondii infection and to clinical toxoplasmosis following infection. This implicates T. gondii as a potential threat to marsupial population viability, and contrasts to what is known of T. gondii in populations of several other host species. We reviewed the literature, and found a lack of scientifically robust evidence addressing the occurrence of T. gondii infection in free-ranging populations of Australian marsupial species, and the impacts of the infection on population health. Key limitations included a lack of studies in free-ranging marsupial populations, study findings susceptible to substantial chance influences, and selection, misclassification and confounding biases. The lack of scientifically robust data available on this topic indicates that assertions that free-ranging populations of Australian marsupials are particularly susceptible to T. gondii infection and to toxoplasmosis are premature. The threat of T. gondii to the viability of free-ranging marsupial populations should therefore be regarded, at this stage, as a hypothesis.

  10. Seroepidemiology of Toxoplasma gondii infection in Bai and Han ethnic groups in southwestern China.

    PubMed

    Li, H-L; Dong, L; Li, Q; Zhang, L; Chen, J; Zou, F-C; Zhu, X-Q

    2015-03-01

    Eating raw pork and/or liver is a custom of the Bai ethnic group in China. Most people living in Dali Bai Autonomous Prefecture, Yunnan Province, southwestern China are of Bai ethnicity. Little is known of the seroprevalence of Toxoplasma gondii in Bai and Han ethnic populations in this region. In the present survey, a total of 555 and 595 blood samples were obtained from Bai and Han ethnic groups in Dali urban and rural areas, respectively. Enzyme-linked immunosorbent assay was performed to examine T. gondii IgG antibodies. Total positive rate of anti-T. gondii IgG in Bai and Han groups in this region was 21·6% (248/1150). The total seroprevalence of T. gondii was significantly higher in the Bai ethnic group (32·3%, 179/555) than in the Han ethnic group (11·6%, 69/595) (P < 0·01). The results of statistical analysis indicated that there was no significant difference between cat feeding/non-cat feeding groups in the Bai ethnic group, the most important risk factor was consumption of raw pork and/or liver for the Bai group, but feeding a cat may be the main route of T. gondii infection for the Han group. Therefore, it is essential to implement integrated strategies to prevent and control T. gondii infection in this unique region of the world.

  11. Toxoplasma gondii seroprevalence in dairy and beef cattle: Large-scale epidemiological study in Estonia.

    PubMed

    Jokelainen, Pikka; Tagel, Maarja; Mõtus, Kerli; Viltrop, Arvo; Lassen, Brian

    2017-03-15

    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 was set as cut-off: samples that tested positive at the dilution 1:100 were defined as positive. The apparent animal-level seroprevalence was 18.62%. At least one seropositive animal was found on 68.86% of the farms, and seropositive cattle were detected in all counties. The seroprevalence appeared to increase with age until five years (60-71 months) of age, but had no obvious pattern in the older animals. Animals of the local Estonian Red breed had higher odds to test seropositive than did animals of the Estonian Holstein breed. Whether the farm focused on dairy or beef cattle was not associated with an animal testing T. gondii seropositive nor with finding at least one T. gondii seropositive animal on the farm. The odds of finding at least one T. gondii seropositive animal on the farm were higher if the herd size was above median (105 in dairy and mixed dairy farms; 35 in beef and mixed beef farms). The results indicate that T. gondii is endemic within the agricultural setting in Estonia and present on the majority of cattle farms.

  12. The Knowns Unknowns: Exploring the Homologous Recombination Repair Pathway in Toxoplasma gondii

    PubMed Central

    Fenoy, Ignacio M.; Bogado, Silvina S.; Contreras, Susana M.; Gottifredi, Vanesa; Angel, Sergio O.

    2016-01-01

    Toxoplasma gondii is an apicomplexan parasite of medical and veterinary importance which causes toxoplasmosis in humans. Great effort is currently being devoted toward the identification of novel drugs capable of targeting such illness. In this context, we believe that the thorough understanding of the life cycle of this model parasite will facilitate the identification of new druggable targets in T. gondii. It is important to exploit the available knowledge of pathways which could modulate the sensitivity of the parasite to DNA damaging agents. The homologous recombination repair (HRR) pathway may be of particular interest in this regard as its inactivation sensitizes other cellular models such as human cancer to targeted therapy. Herein we discuss the information available on T. gondii's HRR pathway from the perspective of its conservation with respect to yeast and humans. Special attention was devoted to BRCT domain-containing and end-resection associated proteins in T. gondii as in other experimental models such proteins have crucial roles in early/late steps or HRR and in the pathway choice for double strand break resolution. We conclude that T. gondii HRR pathway is a source of several lines of investigation that allow to to comprehend the extent of diversification of HRR in T. gondii. Such an effort will serve to determine if HRR could represent a potential targer for the treatment of toxoplasmosis. PMID:27199954

  13. Toxoplasma gondii and Neospora caninum antibodies in dogs from Grenada, West Indies.

    PubMed

    Dubey, J P; Stone, D; Kwok, O C H; Sharma, R N

    2008-06-01

    Toxoplasma gondii and Neospora caninum are structurally similar parasites with many common hosts. The prevalence of antibodies to T. gondii and N. caninum was determined in sera from dogs in Grenada, West Indies. Using a modified agglutination test, antibodies to T. gondii were found in 52 (48.5%) of the 107 dogs, with titers of 1:25 in 17, 1:50 in 19, 1:100 in 7, 1:1,600 in 5, and 1:3,200 or higher in 4. Seroprevalence increased with age from 2.2% in dogs <6 mo old to 18.9% in dogs older than 2 yr, indicating postnatal transmission of T. gondii in this population of canines. There was no correlation between the health of the dogs and the seroprevalence or magnitude of the T. gondii titer. Antibodies to N. caninum were determined by the indirect immunofluorescent antibody test (IFAT). Two of the 107 dogs had N. caninum antibodies (IFAT titers 1:100 and 1:400); these dogs had T. gondii titers of 1:1,600 and 1:50, respectively. Results indicate that these 2 structurally similar protozoa are antigenically different.

  14. GABAergic Signaling Is Linked to a Hypermigratory Phenotype in Dendritic Cells Infected by Toxoplasma gondii

    PubMed Central

    Kumar Mendu, Suresh; Jin, Zhe; Wallin, Robert P. A.; Rethi, Bence; Birnir, Bryndis; Barragan, Antonio

    2012-01-01

    During acute infection in human and animal hosts, the obligate intracellular protozoan Toxoplasma gondii infects a variety of cell types, including leukocytes. Poised to respond to invading pathogens, dendritic cells (DC) may also be exploited by T. gondii for spread in the infected host. Here, we report that human and mouse myeloid DC possess functional γ-aminobutyric acid (GABA) receptors and the machinery for GABA biosynthesis and secretion. Shortly after T. gondii infection (genotypes I, II and III), DC responded with enhanced GABA secretion in vitro. We demonstrate that GABA activates GABAA receptor-mediated currents in T. gondii-infected DC, which exhibit a hypermigratory phenotype. Inhibition of GABA synthesis, transportation or GABAA receptor blockade in T. gondii-infected DC resulted in impaired transmigration capacity, motility and chemotactic response to CCL19 in vitro. Moreover, exogenous GABA or supernatant from infected DC restored the migration of infected DC in vitro. In a mouse model of toxoplasmosis, adoptive transfer of infected DC pre-treated with GABAergic inhibitors reduced parasite dissemination and parasite loads in target organs, e.g. the central nervous system. Altogether, we provide evidence that GABAergic signaling modulates the migratory properties of DC and that T. gondii likely makes use of this pathway for dissemination. The findings unveil that GABA, the principal inhibitory neurotransmitter in the brain, has activation functions in the immune system that may be hijacked by intracellular pathogens. PMID:23236276

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

    PubMed

    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. A qualitative assessment of Toxoplasma gondii risk in ready-to-eat smallgoods processing.

    PubMed

    Mie, Tanya; Pointon, Andrew M; Hamilton, David R; Kiermeier, Andreas

    2008-07-01

    Toxoplasma gondii is one of the most common parasitic infections of humans and other warm-blooded animals. In most adults, it does not cause serious illness, but severe disease may result from infection in fetuses and immunocompromised people. Consumption of raw or undercooked meats has consistently been identified as an important source of exposure to T. gondii. Several studies indicate the potential failure to inactivate T. gondii in the processes of cured meat products, This article presents a qualitative risk-based assessment of the processing of ready-to-eat smallgoods, which include cooked or uncooked fermented meat, pâté, dried meat, slow cured meat, luncheon meat, and cooked muscle meat including ham and roast beef. The raw meat ingredients are rated with respect to their likelihood of containing T. gondii cysts and an adjustment is made based on whether all the meat from a particular source is frozen. Next, the effectiveness of common processing steps to inactivate T. gondii cysts is assessed, including addition of spices, nitrates, nitrites and salt, use of fermentation, smoking and heat treatment, and the time and temperature during maturation. It is concluded that processing steps that may be effective in the inactivation of T. gondii cysts include freezing, heat treatment, and cooking, and the interaction between salt concentration, maturation time, and temperature. The assessment is illustrated using a Microsoft Excel-based software tool that was developed to facilitate the easy assessment of four hypothetical smallgoods products.

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

    PubMed

    Brasil, Arthur Willian de Lima; Parentoni, Roberta Nunes; Feitosa, Thais Ferreira; Bezerra, Camila de Sousa; Vilela, Vinicius Longo Ribeiro; Pena, Hilda Fátima de Jesus; de Azevedo, Sergio Santos

    2015-01-01

    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.

  18. Is Toxoplasma gondii a threat to the conservation of free-ranging Australian marsupial populations?

    PubMed Central

    Hillman, Alison E.; Lymbery, Alan J.; Thompson, R.C. Andrew

    2015-01-01

    It has often been asserted that Australian marsupial species are particularly susceptible to Toxoplasma gondii infection and to clinical toxoplasmosis following infection. This implicates T. gondii as a potential threat to marsupial population viability, and contrasts to what is known of T. gondii in populations of several other host species. We reviewed the literature, and found a lack of scientifically robust evidence addressing the occurrence of T. gondii infection in free-ranging populations of Australian marsupial species, and the impacts of the infection on population health. Key limitations included a lack of studies in free-ranging marsupial populations, study findings susceptible to substantial chance influences, and selection, misclassification and confounding biases. The lack of scientifically robust data available on this topic indicates that assertions that free-ranging populations of Australian marsupials are particularly susceptible to T. gondii infection and to toxoplasmosis are premature. The threat of T. gondii to the viability of free-ranging marsupial populations should therefore be regarded, at this stage, as a hypothesis. PMID:27141439

  19. Cross-sectional survey of Toxoplasma gondii infection in colony cats from urban Florence (Italy).

    PubMed

    Mancianti, Francesca; Nardoni, Simona; Ariti, Gaetano; Parlanti, Dario; Giuliani, Giovanna; Papini, Roberto A

    2010-04-01

    Cats are the key species in the epidemiology of Toxoplasma gondii infection, even if the proportion of subjects excreting oocysts is low. The aim of the present paper was to obtain information about seroprevalence, oocyst shedding rate and presence of T gondii DNA in faeces collected from an urban population of colony cats in Florence (Tuscany). Fifty European shorthair feral cats were examined for anti-T gondii specific antibodies by a modified agglutination test (MAT), and for oocysts by microscopic examination and for faecal protozoal DNA, by means of a nested polymerase chain reaction (n-PCR) protocol. Twenty-two out of 50 serum samples (44%) were MAT positive. T gondii oocysts were not detected in any of the examined faecal samples. Eight out of 50 faecal specimens (16%) were n-PCR positive and sequencing of the bands was specific for T gondii. Detection by combination of the two methods was higher than single techniques and enhanced the detection of T gondii up to 48%. Our results suggest that the use of MAT plus PCR in faeces may be the best choice for diagnosis of feline toxoplasmosis. Further studies to ascertain the real infectivity of the copro-PCR positive subjects are required.

  20. Land use and soil contamination with Toxoplasma gondii oocysts in urban areas.

    PubMed

    Gao, Xiang; Wang, Hongbin; Wang, Huan; Qin, Hongyu; Xiao, Jianhua

    2016-10-15

    Because soil contaminated with Toxoplasma gondii oocysts is increasingly recognized as a major source of infection for humans, in this study, we investigated the spatial pattern of soil contamination with T. gondii oocysts in urban area of northeastern Mainland China. From April 2014 to May 2015, more than 9000 soil samples were collected. Detection of T. gondii oocysts was performed applying real-time quantitative PCR. Sensitivity was improved by analyzing four replicates for each sampling point. T. gondii was detected in 30.3% of all samples. Subsequently, a maximum entropy model was used to evaluate the effect of land use and intrinsic soil properties on the risk of contamination with oocysts. Jackknife analysis revealed that the likelihood for positive results is significantly enhanced in soil originating from foci of human habitation, wood land and grass land. Furthermore, soil temperature and humidity significantly influence the probability of contamination with T. gondii oocysts. Our findings indicate that land use may affect distribution of T. gondii oocysts in urban areas.

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

    PubMed

    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.

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

    PubMed

    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.

  3. Triplex PCR using new primers for the detection of Toxoplasma gondii.

    PubMed

    Rahumatullah, Anizah; Khoo, Boon Yin; Noordin, Rahmah

    2012-06-01

    Molecular methods are used increasingly for the detection of Toxoplasma gondii infection. This study developed a rapid, sensitive, and specific conventional triplex PCR for the detection of the B1 gene and ITS1 region of T. gondii using newly designed primers and an internal control based on the Vibrio cholerae HemM gene. The annealing temperature and concentrations of the primers, MgCl(2), and dNTPs were optimized. Two sets of primers (set 1 and 2) were tested, which contained different segments of the T. gondii B1 gene, 529 repeat region and ITS1 region. A series of sensitivity tests were performed using parasite DNA, whole parasites, and spiked human body fluids. Specificity tests were performed using DNA from common protozoa and bacteria. The newly developed assay based on set 2 primers was found to be specific and sensitive. The test was capable of detecting as little as 10 pg T. gondii DNA, 10(4) tachyzoites in spiked body fluids, and T. gondii DNA in the organ tissues of experimentally infected mice. The assay developed in this study will be useful for the laboratory detection of T. gondii infection.

  4. Population genetics of Toxoplasma gondii: new perspectives from parasite genotypes in wildlife

    PubMed Central

    Wendte, Jered M.; Gibson, Amanda K.; Grigg, Michael E.

    2011-01-01

    Toxoplasma gondii, a zoonotic protozoal parasite, is well-known for its global distribution and its ability to infect virtually all warm-blooded vertebrates. Nonetheless, attempts to describe the population structure of T. gondii have been primarily limited to samples isolated from humans and domesticated animals. More recent studies, however, have made efforts to characterize T. gondii isolates from a wider range of host species and geographic locales. These findings have dramatically changed our perception of the extent of genetic diversity in T. gondii and the relative roles of sexual recombination and clonal propagation in the parasite’s lifecycle. In particular, identification of novel, disease-causing T. gondii strains in wildlife has raised concerns from both a conservation and public health perspective as to whether distinct domestic and sylvatic parasite gene pools exist. If so, overlap of these cycles may represent regions of high probability of disease emergence. Here, we attempt to answer these key questions by reviewing recent studies of T. gondii infections in wildlife, highlighting those which have advanced our understanding of the genetic diversity and population biology of this important zoonotic pathogen. PMID:21824730

  5. Genetic characterization of Toxoplasma gondii from domestic animals in central China.

    PubMed

    Qian, W F; Yan, W C; Wang, T Q; Shao, X D; Zhai, K; Han, L F; Lv, C C

    2015-09-01

    Toxoplasma gondii is an obligate intracellular parasite that has a remarkable ability to infect almost all warm-blooded animals, including humans. This study was aimed to determine the genetic characteristics of T. gondii isolates from domestic animals in Henan Province, central China. A total of 363 DNA samples, including 208 from hilar lymph nodes of pigs, 36 from blood samples of cats, 12 from tissues of aborted bovine fetuses and 107 from blood samples of dams with history of abortion in Henan Province, were examined for the presence of T. gondii by nested PCR based on B1 gene. The positive DNA samples were further genotyped by PCR-RFLP at 11 markers, including SAG1, (3'+ 5') SAG2, alt.SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico. DNA samples from 9 pigs, 5 cats, and 4 dairy cows were T. gondii B1 gene positive. Nine samples were successfully genotyped at all genetic loci, of which 5 samples from pigs, and 2 from cats were identified as ToxoDB genotype #9, and 2 samples from cows belonged to ToxoDB genotype #225. To our knowledge, the present study is the second report of genetic typing of T. gondii isolates from cattle in China, and the first report of T. gondii ToxoDB#225 from cattle.

  6. FlowCytomix analysis for Toxoplasma gondii infection in pregnant women in central Taiwan.

    PubMed

    Chou, C S; Lin, L Y; Chen, K M; Lai, S C

    2011-07-01

    The study was to determine the seroprevalence of toxoplasmosis in the sera of pregnant women in central Taiwan and to investigate the levels of cytokine in the sera of pregnant women with Toxoplasma gondii infection. The 220 blood samples were collected from pregnant women. The haematological parameters of peripheral blood were analysed by a haematology analyser. Serum samples of the pregnant women were analysed by a commercially available anti-T. gondii IgM/IgG antibody enzyme-linked immunosorbent assay (ELISA) kit and FlowCytomix assays. Six (2.7%) of the sera samples had IgM anti-T. gondii antibodies, and twenty (9.1%) had T. gondii IgG seropositive. All six IgM seropositive samples had low IgG avidity, indicative of acute infection. Total white blood cells and eosinophils were statistically significantly increased (p<0.05) in pregnant women with T. gondii infection, as compared with healthy pregnant women. Th1 cytokines IFN-γ, IL-1β, IL-2 and IL-12 p70, and Th2 cytokines IL-10 in pregnant women with T. gondii IgM/IgG seropositive were significantly increased (p<0.05), as compared with healthy pregnant women. These results showed that both of Th1 and Th2 cytokines play an important role in the toxoplasmosis of pregnant women.

  7. rROP2186–533: A Novel Peptide Antigen for Detection of IgM Antibodies Against Toxoplasma gondii

    PubMed Central

    Liu, Lili; Liu, Tingting; Yu, Li; Cai, Yihong; Zhang, Aimei; Xu, Xiucai; Luo, Qingli; Hu, Yuansheng; Song, Wenjian; Lun, Zhaorong; Lu, Fangli; Wang, Yong

    2012-01-01

    Abstract Toxoplasma gondii infections are prevalent in a wide range of mammalian hosts including humans. Infection in pregnant women may cause the transmission of parasite to the fetus that makes serious problems. IgM antibodies against Toxoplasma (Toxo-IgM) have been believed to be significant indicators for both recently acquired and congenital toxoplasmosis. So far, however, there has not been any recognized protein of T. gondii that specifically reacts to IgM antibodies. Here, an antigen exclusively for detection of IgM antibodies screened by two-dimensional electrophoresis and mass spectrometry has been reported. The study identified 13 Toxoplasma proteins probed by IgG antibodies and one (rhpotry protein 2 [ROP2]) by IgM antibodies with human sera of Toxo-IgM–-IgG+ and -IgM+-IgG–, respectively, which had been prescreened by Toxo-IgM and -IgG commercial kits from the suspected cases. Following cloning, expression, and purification of the fragment of ROP2186–533, an enzyme-linked immunosorbent assay with rROP2186–533 to measure IgM and IgG antibodies was developed. As a result, 100%(48/48) of sera with Toxo-IgM+-IgG–showed positive Toxo-IgM but none of them (0%) showed positive Toxo-IgG when rROP2186–533 was used as antigen. Neither Toxo-IgG nor Toxo-IgM antibodies were found when tested with 59 sera of Toxo-IgM–-IgG+. These results indicate that rROP2186–533 could be used as an antigen that specifically capture Toxo-IgM antibodies and may have a high potential in the serological diagnosis of both acute acquired and congenital toxoplasmosis. PMID:22085219

  8. SEROPREVALENCE AND RISK FACTORS ASSOCIATED WITH Toxoplasma gondii INFECTION AMONG RURAL COMMUNITIES IN NORTHERN IRAN

    PubMed Central

    ROSTAMI, Ali; SEYYEDTABAEI, Seyyed Javad; AGHAMOLAIE, Somayeh; BEHNIAFAR, Hamed; LASJERDI, Zohreh; ABDOLRASOULI, Alireza; MEHRAVAR, Saeed; ALVARADO-ESQUIVEL, Cosme

    2016-01-01

    SUMMARY Toxoplasmosis is the fourth most common cause of hospitalization and the second cause of death due to food-borne infections. We conducted a cross-sectional study to determine the prevalence, disease awareness and risk factors associated with toxoplasmosis among rural communities in Northern Iran. Data were obtained from serological testing and from participant's questionnaires and were analyzed using a logistic regression. Of the 630 participants, 465 (73.8%), and 12 (1.9%) had IgG and both IgG and IgM anti-Toxoplasma gondii antibodies, respectively. In the logistic regression analysis, T. gondii seropositivity was associated with the following factors: age, occupation, consumption of undercooked meat, and of unwashed raw vegetables or fruits (p < 0.001). Our study showed a high prevalence of T. gondii infection in the general population of Northern Iran. A health program is needed to increase the public awareness of toxoplasmosis, and its associated risk factors. PMID:27680175

  9. Congenital toxoplasmosis in wild boar (Sus scrofa) and identification of the Toxoplasma gondii types involved.

    PubMed

    Calero-Bernal, Rafael; Gómez-Gordo, Luis; Saugar, José María; Frontera, Eva; Pérez-Martín, Juan Enrique; Reina, David; Serrano, Francisco Javier; Fuentes, Isabel

    2013-10-01

    Congenital toxoplasmosis has been little described in wild animals. We report a case of vertical transmission in wild boar (Sus scrofa). Necropsy and histopathologic examination of a pregnant female and her three fetuses revealed all to have lesions compatible with acute toxoplasmosis. Nested polymerase chain reaction B1 gene detected Toxoplasma gondii in maternal (heart and diaphragm) and fetal (central nervous system, retina, optic nerve, heart, lung, tongue, and diaphragm) samples. The mother had a mixed infection of T. gondii types I and III. One fetus with type III infection developed no malformations, but the others-one with type I infection and one infected by types I and III-showed bilateral ocular agenesis, prognathism, and agenesis of the nasal cartilage. These results suggest the pathogenicity of the various T. gondii types may differ in wild boars.

  10. Toxoplasma gondii in Vancouver Island cougars (Felis concolor vancouverensis): serology and oocyst shedding.

    PubMed

    Aramini, J J; Stephen, C; Dubey, J P

    1998-04-01

    One of 12 necropsied cougars (Felis concolor vancouverensis) from Vancouver Island, British Columbia, Canada, shed Toxoplasma gondii oocysts confirmed by mouse bioassay. Eleven of the 12 cougars (92%) had antibodies to T. gondii by the modified agglutination test with titers of <1:25 (1 cougar), 1:50 (8 cougars), and 1:500 (3 cougars). One additional cougar fecal sample collected from the Victoria watershed environment also contained T. gondii oocysts. In 1995, the largest reported outbreak of human toxoplasmosis was linked to municipal drinking water in Victoria, British Columbia. This study supports the initial hypothesis at the time of the outbreak that not only domestic cats, but also cougars, pose a risk to Victoria's water supply.

  11. Toxoplasma gondii from liquid nitrogen for continuous cell culture: methods to maximise efficient retrieval.

    PubMed

    Mavin, S; Evans, R; Chatterton, J M W; Ashburn, D; Joss, A W L; Ho-Yen, D O

    2003-01-01

    This study aims to increase the efficiency of continuous growth of Toxoplasma gondii in HeLa cells from tachyzoite stocks frozen in liquid nitrogen. Freezing and retrieval of tachyzoites for continuous cell culture requires more stringent protocols than those published for animal culture. The freezing and retrieval conditions are optimised so that a quality harvest (> or = 1 x 10(6) tachyzoites/mL, > or = 90% viability) can be produced using T. gondii recovered from liquid nitrogen as fast and reliably as possible. Retrieval success rate increased from 36% to 100%. An improved freezing procedure using chilled reagents and freshly harvested parasites, and adoption of an effective recovery protocol with retrieval of 3 x 10(7) tachyzoites into 75 cm2 flasks, change of maintenance media after six hours and subsequent blind passage all contributed to this success. The result is faster and more dependable production of T. gondii for diagnostic and experimental use.

  12. Toxoplasma gondii from liquid nitrogen for continuous cell culture:methods to maximise efficient retrieval.

    PubMed

    Mavin, S; Evans, R; Chatterton, J M W; Ashburn, D; Joss, A W L; Ho-Yen, D O

    2003-01-01

    This study aims to increase the efficiency of continuous growth of Toxoplasma gondii in HeLa cells from tachyzoite stocks frozen in liquid nitrogen. Freezing and retrieval of tachyzoites for continuous cell culture requires more stringent protocols than those published for animal culture. The freezing and retrieval conditions are optimised so that a quality harvest (≥ 1 x 10(6) tachyzoites/mL, ≥ 90% viability) can be produced using T. gondii recovered from liquid nitrogen as fast and reliably as possible. Retrieval success rate increased from 36% to 100%. An improved freezing procedure using chilled reagents and freshly harvested parasites, and adoption of an effective recovery protocol with retrieval of 3 x 10(7) tachyzoites into 75cm(2) flasks, change of maintenance media after six hours and subsequent blind passage all contributed to this success. The result is faster and more dependable production of T. gondii for diagnostic and experimental use.

  13. Seroprevalence of Toxoplasma gondii infection in zoo and domestic animals in Jiangxi Province, China

    PubMed Central

    Luo, Houqiang; Li, Kun; Zhang, Hui; Gan, Ping; Shahzad, Muhammad; Wu, Xiaoxing; Lan, Yanfang; Wang, Jiaxiang

    2017-01-01

    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. PMID:28224883

  14. Toxoplasma gondii calcium-dependent protein kinase 1 is a target for selective kinase inhibitors

    PubMed Central

    Ojo, Kayode K; Larson, Eric T; Keyloun, Katelyn R; Castaneda, Lisa J; DeRocher, Amy E; Inampudi, Krishna K; Kim, Jessica E; Arakaki, Tracy L; Murphy, Ryan C; Zhang, Li; Napuli, Alberto J; Maly, Dustin J; Verlinde, Christophe LMJ; Buckner, Frederick S; Parsons, Marilyn; Hol, Wim GJ; Merritt, Ethan A; Van Voorhis, Wesley C

    2010-01-01

    New drugs are needed to treat toxoplasmosis. Toxoplasma gondii calcium-dependent protein kinases (TgCDPKs) are attractive targets because they are absent in mammals. We show that TgCDPK1 is inhibited by low nanomolar levels of bumped kinase inhibitors (BKIs), compounds designed to be inactive against mammalian kinases. Cocrystal structures of TgCDPK1 with BKIs confirm that the structural basis for selectivity is due to the unique glycine gatekeeper residue in the ATP-binding site at residue 128. We show that BKIs interfere with an early step in T. gondii infection of human cells in culture. Furthermore, we show that TgCDPK1 is the in vivo target of BKIs because T. gondii cells expressing a glycine to methionine gatekeeper mutant enzyme show significantly decreased sensitivity to this class of selective kinase inhibitors. Thus, design of selective TgCDPK1 inhibitors with low host toxicity may be achievable. PMID:20436472

  15. Seroprevalence of antibodies to Toxoplasma gondii in the Pennsylvania bobcat (Lynx rufus rufus).

    PubMed

    Mucker, Eric M; Dubey, J P; Lovallo, Matthew J; Humphreys, Jan G

    2006-01-01

    From 2000 to 2002 bobcat blood samples were collected, in association with the Pennsylvania Game Commission, during the recently reactivated bobcat hunting and trapping season. Sex, age, and county/township data were recorded for each animal. Blood was tested for antibodies to Toxoplasma gondii using the modified agglutination test. In the 2-yr study, 131 bobcat samples were collected in 14 Pennsylvania counties and 109 (83%) of these had antibodies to T. gondii (titer>or=25). A two-way Chi-Square test (95% confidence interval) yielded no significance differences in antibody prevalence between males (83%) and females (88%) or adults (83%) and juveniles (77%). All 14 counties had at least one bobcat with antibodies to T. gondii.

  16. Atypical Toxoplasma gondii strain from a free-living jaguar (Panthera onca) in French Guiana.

    PubMed

    Demar, M; Ajzenberg, D; Serrurier, B; Dardé, M L; Carme, B

    2008-02-01

    Like domestic cats, wild felids are involved in the complete infective cycle of Toxoplasma gondii because they can host in their gastrointestinal tract sexually mature parasites and shed infective oocysts in their feces. We report, to our knowledge, the first isolation and molecular characterization of a T. gondii strain from the heart tissue of a free-living jaguar (Panthera onca) in French Guiana. Sequencing at six polymorphic markers indicated that the jaguar isolate had an atypical genotype, including an allele at TgM-A previously found only in isolates from South America, and an allele at GRA6, which was previously reported only in Californian sea otter isolates. These findings are consistent with the recent description of atypical T. gondii strains involved in severe toxoplasmoses in immunocompetent patients in French Guiana that seemed to be linked to a neotropical forest-based cycle involving wild cats and their prey.

  17. Detection of Toxoplasma gondii by PCR and Mouse Bioassay in Rodents of Ahvaz District, Southwestern Iran

    PubMed Central

    Saki, J.; Khademvatan, S.

    2014-01-01

    Toxoplasma gondii is obligate coccidian zoonotic parasite. Felidae family is definitive and wide ranges of warm-blooded vertebrates are intermediate hosts for the parasite. Rodents are measured as an important source of T. gondii infection for the definitive host. Thus, this study aimed to investigate Toxoplasm infection in rodents of Ahvaz district, southwest of Iran. A total of 100 rodents (73 Rattus norvegicus, 21 Rattus rattus, and 6 Mus musculus) were collected and studied by GRA6PCR and mouse bioassay. The finding indicated that 6 out of 100 (6%) and 2 out of 100 (2%) samples were positive by PCR and mouse bioassay, respectively. The results show notable chronic infection in the rodent and potential transmission of the infection among animal and men in the region. Accordingly, this study recommended investigating of the T. gondii infection in definitive and other intermediate hosts in other points of Khuzestan province, Southwest, Iran. PMID:24605327

  18. Antibodies to Toxoplasma gondii and Neospora caninum in captive neotropical and exotic wild canids and felids.

    PubMed

    André, M R; Adania, C H; Teixeira, R H F; Silva, K F; Jusi, M M G; Machado, S T Z; de Bortolli, C P; Falcade, M; Sousa, L; Alegretti, S M; Felippe, P A N; Machado, R Z

    2010-10-01

    This study was designed to detect antibodies to Toxoplasma gondii and Neospora caninum in wild captive carnivores maintained in Brazilian zoos. Blood samples were collected from 142 Brazilian wild felids and 19 exotic felids in zoos, and 3 European wolves (Canis lupus) and 94 Brazilian wild canids maintained in captivity in Brazilian zoos of São Paulo, Mato Grosso states and Federal District. One hundred and two (63.4%) and 70 (50.3%) of the 161 wild felids tested were seropositive for T. gondii and N. caninum by indirect immunofluorescent assay test (IFAT), respectively. Among sampled wild canids, 49 (50.5%) and 40 (41.2%) animals were seropositive for T. gondii and N. caninum antigens by IFAT, respectively. To our knowledge, this is the first serological detection of antibodies to N. caninum in Brazilian wild captive felids and bush dogs (Speothos venaticus (Lund)).

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

    SciTech Connect

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

    2009-01-16

    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{sub 2} and PIP{sub 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.

  20. Frequency of antibodies to Toxoplasma gondii in stray dogs of Oaxaca, México.

    PubMed

    Cedillo-Peláez, C; Díaz-Figueroa, I D; Jiménez-Seres, M I; Sánchez-Hernández, G; Correa, D

    2012-08-01

    We studied the frequency of antibodies against Toxoplasma gondii in stray dogs in the city of Oaxaca, Mexico through the evaluation of 154 sera by indirect ELISA. A frequency of 61.7% was found; it was higher in males (45 of 65, 69.2%) than in females (49 of 89, 55.0%), although this difference was not statistically significant. An increase in frequency was observed with age, the lowest being among animals younger than 1 yr (4 of 20, 20.0%) and the highest in dogs older than 7 yr (21 of 25, 84.0%). This is the first study in dogs of this region of Mexico and revealed high T. gondii transmission and evidence of early exposure in animals that are in close contact with contaminated water or raw meat, or both. Further studies are needed in order to understand the role of T. gondii infection in public health.

  1. Occurrence of antibodies to Toxoplasma gondii in mules and donkeys in the northeast of Brazil.

    PubMed

    de Oliveira, Elizete; de Albuquerque, Pedro Paulo Feitosa; de Souza Neto, Orestes Luiz; Faria, Eduardo Bento; Júnior, José Wilton Pinheiro; Mota, Rinaldo Aparecido

    2013-04-01

    The aim of the present study was to investigate antibodies to Toxoplasma gondii in the serum of mules and donkeys bred in the northeast of Brazil. In total, 483 samples were used (395 mules and 88 donkeys) from 4 states (Pernambuco, Rio Grande do Norte, Paraíba, and Sergipe). The indirect immunofluorescence reaction (IFI) technique was used to investigate antibodies to T. gondii with a cut-off point of 64. Positive frequencies of 23.8% and 43.2% were recorded for mules and donkeys, respectively. The state of Pernambuco had the highest prevalence of positive samples (29%) with statistically significant differences for species (P < 0.001) and state (P = 0.048). This is the first study of antibodies to T. gondii in mules and donkeys in these 4 states of the northeastern region of Brazil and serves as a warning to health authorities regarding the risks of ingesting equine meat.

  2. Toxoplasma gondii infection and testosterone congruently increase tolerance of male rats for risk of reward forfeiture.

    PubMed

    Tan, Donna; Vyas, Ajai

    2016-03-01

    Decision making under risk involves balancing the potential of gaining rewards with the possibility of loss and/or punishment. Tolerance to risk varies between individuals. Understanding the biological basis of risk tolerance is pertinent because excessive tolerance contributes to adverse health and safety outcomes. Yet, not much is known about biological factors mediating inter-individual variability in this regard. We investigate if latent Toxoplasma gondii infection can cause risk tolerance. Using a rodent model of the balloon analogous risk task, we show that latent T. gondii infection leads to a greater tolerance of reward forfeiture. Furthermore, effects of the infection on risk can be recapitulated with testosterone supplementation alone, demonstrating that greater testosterone synthesis by the host post-infection is sufficient to change risk tolerance. T. gondii is a frequent parasite of humans and animals. Thus, the infection status can potentially explain some of the inter-individual variability in the risky decision making.

  3. Seroprevalence of Toxoplasma gondii infection in zoo and domestic animals in Jiangxi Province, China.

    PubMed

    Luo, Houqiang; Li, Kun; Zhang, Hui; Gan, Ping; Shahzad, Muhammad; Wu, Xiaoxing; Lan, Yanfang; Wang, Jiaxiang

    2017-01-01

    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.

  4. Detection and genotyping of Toxoplasma gondii isolated from soil in Ahvaz, southwest of Iran.

    PubMed

    Saki, J; Khademvatan, S; Yousefi, E; Tavalla, M; Abdizadeh, R

    2017-03-01

    To detection and genotype of Toxoplasma gondii isolated from soil in Ahvaz, southwest of Iran. Between August 2011 and May 2012 at different sites located in the area of the Ahvaz city south west Iran. A total of 200 soil samples were taken from different points of the region. Oocysts were recovered using the flotation method. Then, PCR reactions targeting the GRA6 gene were performed for specific T. gondii detection. The positive samples were studied by RFLP (random amplified fragment length polymorphism) using MseI enzymes to confirm the parasite linage. Toxoplasma DNA was found in 18 samples. Among them, 12 samples were successfully genotyped as GRA6 type III and 6 as GRA6 Type II. This is the first investigation detecting and genotyping T. gondii oocyst in environmental soil samples of Ahvaz, South west of Iran. The results of this study indicated that soil contaminated with T. gondii oocysts especially in public park may play a role in the epidemiology of human toxoplasmosis in southwest of Iran.

  5. A study on the status of inflammatory systems in camels naturally infected with Toxoplasma gondii.

    PubMed

    Azma, Fatemeh; Razavi, Seyed Mostafa; Nazifi, Saeed; Rakhshandehroo, Ehsan; Sanati, Ahmad Reza

    2015-06-01

    Toxoplasma gondii is a unique intracellular parasite with a worldwide distribution. This parasite infects a variety of cells in a wide range of animal species such as dromedary camels (Camelus dromedarius). In order to evaluate the pattern of possible changes in the blood level of some inflammatory mediators and antioxidant enzymes in camels infected with T. gondii, blood samples were taken from a total of 493 dromedary camels and serum concentrations of inflammatory mediators, acute phase proteins and antioxidant enzymes were measured. According to serological data, no seropositivity was found for anti-T. gondii IgM in serum samples; however, 49 camels (9.93 %) showed positive titrations for anti-Toxoplasma IgG. The analyses of data in seropositive animals showed significant increases (P < 0.05) in the serum level of IL-1β and adenosine deaminase activity; however, IFN-γ and TNF-α demonstrated no significant changes in serum samples of the infected camels. In addition, while major acute phase proteins (haptoglobin (Hp) and serum amyloid A (SAA)) were markedly elevated in infected camels, the activity of antioxidant enzymes (SOD and GPX) was remarkably decreased in the blood samples of infected animals. Thus, during the chronic infection in camels, T. gondii can promote significant rises in concentrations of some cytokines (such as IL-1β), acute phase proteins and adenosine deaminase.

  6. Establishment of replacement International Standard 13/132 for human antibodies to Toxoplasma gondii.

    PubMed

    Rijpkema, Sjoerd; Hockley, Jason; Rigsby, Peter; Guy, Edward C

    2016-09-01

    Sixteen laboratories carried out a collaborative study to validate 13/132 as a replacement International Standard (IS) for TOXM (3rd IS for anti-Toxoplasma Serum, Human, 1000 IU). 13/132 is a freeze dried preparation of pooled human plasma from six donors who experienced a recent Toxoplasma gondii infection. The potency of 13/132 was compared to TOXM and 01/600 (1st IS for anti-Toxoplasma IgG, Human, 20 IU). Samples were tested for IgA, IgG, IgG avidity and IgM in agglutination assays; enzyme linked immunosorbent assays (ELISA), enzyme linked fluorescent assays, immunoblots, immunofluorescence assays and the Sabin-Feldman dye test for Ig. 13/132 was strongly positive for Ig, IgA, IgG and IgM and the reproducibility was very good. 13/132 contains high levels of anti-Toxoplasma Ig, IgG and IgM and its potency falls between TOXM and 01/600. The avidity of IgG was found to be low, similar to the avidity of IgG from TOXM. 13/132 was established by the Expert Committee on Biological Standardization as the 4th IS for Antibodies, Human, to T. gondii with an assigned unitage of 160 IU per ampoule for Ig by dye test and 263 U per ampoule for IgG by ELISA.

  7. Seroepidemiology of Toxoplasma gondii amongst Pregnant Women in Jazan Province, Saudi Arabia

    PubMed Central

    Aqeely, Hussein; El-Gayar, Eman K.; Najmi, Abdullah; Alvi, Ayesha; Bani, Ibrahim; Mahfouz, Mohamed Salih; Abdalla, Saif Elden; Elhassan, Ibrahim M.

    2014-01-01

    Background. Toxoplasma gondii (T. gondii) is an obligate intracellular protozoan parasite of worldwide distribution. There is limited information about the seroprevalence of toxoplasmosis in the southern area of Saudi Arabia. The current study was carried out to determine the prevalence of T. gondii in pregnant women in Jazan province. Materials and Methods. The study was conducted between January and June 2013 and included 195 pregnant women, data on sociodemographic and predisposing factors were collected from each participant. Venous blood samples were collected following standard operating procedures. Serological analysis for latent toxoplasmosis (levels of IgG) and active toxoplasmosis (IgM) was done using Enzyme Linked Immunosorbent Assay (ELISA). Results. The overall seroprevalence of T. gondii in the study area was 24.1%. The seroprevalence of anti-Toxoplasma IgG was 20% (39 out of 195), whereas IgM seropositivity was 6.2% (12 out of 195). Only 4 pregnant women tested positive for both IgG and IgM. The highest IgG and IgM seroprevalence was among the study participants aged 35 to 39 years (13.5% and 35.1%, resp.). The seropositivity rate of T. gondii-specific antibodies was higher among pregnant women from the urban areas than those from rural communities (7.4% versus 0% and 21% versus 15.4% for IgM and IgG, resp.). Conclusions. The seroprevalence of T. gondii was high in pregnant woman in Jazan. The prevalence of toxoplasmosis increases with increase of age. Awareness health education program in Jazan needs to be maintained and developed to targeted pregnant women. PMID:25484905

  8. Recombinant Toxoplasma gondii phosphoglycerate mutase 2 confers protective immunity against toxoplasmosis in BALB/c mice

    PubMed Central

    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. PMID:26984115

  9. Increased expressions of ADAMTS-13 and apoptosis contribute to neuropathology during Toxoplasma gondii encephalitis in mice.

    PubMed

    Dincel, Gungor Cagdas; Atmaca, Hasan Tarik

    2016-06-01

    Toxoplasma gondii (T. gondii) is a protozoan parasite with the potential of causing severe encephalitis among immunocompromised humans and animals. Our previous study showed that T. gondii induces high nitric oxide (NO) production, high glial activation (GFAP) and neurofilament expressions, leading to severe neurodegeneration in toxoplasma encephalitis (TE) in the central nervous system (CNS). The aim of this experimental study was to investigate ADAMTS-13 expression and apoptosis in CNS and to identify whether they have any correlation with toxoplasmosis neuropathology and neurodegeneration. Mice were infected with ME49 strain T. gondii and the levels of ADAMTS-13, caspase 3, caspase 8, caspase 9, TNFR1 and Bcl-xL expressions were examined in brain tissues by immunohistochemistry, during the development and establishment of chronic infections at 10, 30 and 60 days post-infection. Results of the study revealed that the levels of ADAMTS-13 (P < 0.005), caspase 3 (P < 0.05), caspase 8 (P < 0.05), caspase 9 (P < 0.005) and TNFR1 (P < 0.05) expressions in the brain markedly increased while Bcl-xL expression decreased (P < 0.005). The most prominent finding from our study was that 10, 30 and 60 days post-infection ADAMTS-13 increased significantly and this may play an important role in the regulation and protection of the blood-brain barrier integrity and CNS microenvironment in TE. These results also suggest that T. gondii-mediated apoptosis might play a pivotal role and a different type of role in the mechanism of neurodegeneration and neuropathology in the process of TE. Furthermore, expression of ADAMTS-13 might give an idea of the progress and is critical for diagnosis of this disease. To the best of the authors' knowledge, this is the first report on ADAMTS-13 expression in the CNS of T. gondii-infected mice.

  10. Recombinant Toxoplasma gondii phosphoglycerate mutase 2 confers protective immunity against toxoplasmosis in BALB/c mice.

    PubMed

    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.

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

    PubMed Central

    Alvarado-Esquivel, Cosme; Mercado-Suarez, Miguel Francisco; Rodríguez-Briones, Alfredo; Fallad-Torres, Laura; Ayala-Ayala, Julio Octavio; Nevarez-Piedra, Luis Jorge; Duran-Morales, Ehecatl; Estrada-Martínez, Sergio; Liesenfeld, Oliver; Márquez-Conde, José Ángel; Martínez-García, Sergio Arturo

    2007-01-01

    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 with educational

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

    PubMed

    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).

  13. Novel Triazine JPC-2067-B Inhibits Toxoplasma gondii In Vitro and In Vivo

    PubMed Central

    Mui, Ernest J.; Schiehser, Guy A.; Milhous, Wilbur K.; Hsu, Honghue; Roberts, Craig W.; Kirisits, Michael; Muench, Stephen; Rice, David; Dubey, J. P.; Fowble, Joseph W.; Rathod, Pradipsinh K.; Queener, Sherry F.; Liu, Susan R.; Jacobus, David P.; McLeod, Rima

    2008-01-01

    Background and Methodology 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-trifluoromethoxyphenoxy)propyloxy)-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-trifluoromethoxyphenyloxy)propyl 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. Principal Findings and Conclusions 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. Significance JPC-2056/JPC-2067-B have potential to be more effective and possibly less toxic treatments for toxoplasmosis than currently available medicines. PMID:18320016

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

    PubMed

    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

  15. Toxoplasma gondii: Pig seroprevalence, associated risk factors and viability in fresh pork meat.

    PubMed

    Herrero, Laura; Gracia, María Jesús; Pérez-Arquillué, Consuelo; Lázaro, Regina; Herrera, Marta; Herrera, Antonio; Bayarri, Susana

    2016-07-15

    This study was conducted on 161 fattening pig farms located in Aragón (Northeast Spain). Serum samples from 1200 pigs were tested for antibodies against T. gondii by indirect immunofluorescence assay (IFA). Antibodies to T. gondii (≥1:20) were detected in 301 pigs (24.52%). The seroprevalence observed in the present study indicates a widespread exposure to T. gondii, as seropositive pigs were found in 96.67% of the farms studied although low pig titers were determined. Risk factors associated with T. gondii seroprevalence were presence of cats in or around the farms, presence of dogs around the facilities, low number of animals in the farms, poor hygiene and bad maintenance of the farms. Finally, it was observed that where rodent baits were used, Toxoplasma prevalence was lower. Risk management measures including control of cats and rodents on the farms, among others, could help to reduce the observed prevalence levels. By mouse bioassay, T. gondii was detected in 73.7% and isolated from 42.1% of seropositive pigs and a significant relation between the titers of pigs and the presence and viability of T. gondii in the tissues was found. The detection of T. gondii is not possible by currently practiced meat inspection. Nevertheless, the increased probability of detecting viable forms of T. gondii in tissues of pigs with titers ≥1: 80 could be used as the cutoff for discriminating higher risk animals, and could be used as an effective control tool for the industry of cured meat products. In practical terms, we propose that this value could be used as a critical limit in the HACCP system.

  16. The role of hormones on Toxoplasma gondii infection: a systematic review

    PubMed Central

    Galván-Ramírez, María de la Luz; Gutiérrez-Maldonado, Adrián Fernando; Verduzco-Grijalva, Fabiola; Jiménez, Judith Marcela Dueñas

    2014-01-01

    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 T. 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: Thirty 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 17β-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 T. gondii infection and its relationship with hormones. This systematic review suggests that hormones modulate T. 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 T. gondii infectious process. PMID:25346725

  17. Prevalence of Toxoplasma gondii infection in wild birds in Durango, Mexico.

    PubMed

    Alvarado-Esquivel, C; Rajendran, C; Ferreira, L R; Kwok, O C H; Choudhary, S; Alvarado-Esquivel, D; Rodríguez-Peña, S; Villena, I; Dubey, J P

    2011-10-01

    There is a lack of information concerning the prevalence of Toxoplasma gondii infection in wild birds in Mexico. In the present study, serum samples and tissues from 653 birds from Durango State, Mexico, were evaluated for T. gondii infection. Antibodies to T. gondii (modified agglutination test, titer 1∶25 or higher) were found in 17 (2.6%) of the 653 birds, including 1 of 2 curve-billed thrashers (Toxostoma curvirostre), 2 (1 Anas platyrhynchos, 1 Anas diazi) of 4 ducks, 1 of 2 eagles (Aquila sp.), 5 (27.8%) of 18 great-tailed grackles (Quiscalus mexicanus), 7 (1.3%) of 521 rock pigeons (Columba livia), and 1 (14.3%) of 7 quail (Coturnix coturnix). The seroprevalence of T. gondii infection in birds captured in a park outside the city zoo (11.6%, 8/69) was significantly higher than that found in birds from other regions (1.5%, 9/584, OR  =  8.38; 95% CI: 2.82-24.77; P  =  0.0001). Brains and hearts of 23 birds (17 seropositive, 6 seronegative) were bioassayed in mice for the isolation of T. gondii . Viable T. gondii was isolated from 1 of 7 seropositive pigeons. The DNA obtained from the T. gondii isolate from the pigeon was genotyped using the PCR-RFLP typing using 11 markers (B1, SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico) and revealed an atypical genotype. This is the first report of T. gondii infection in great-tailed grackles, the Mexican duck, and curved-billed thrashers and the first survey of wild birds in Mexico.

  18. Isolation and genetic characterization of Toxoplasma gondii from alpaca (Vicugna pacos) and sheep (Ovis aries).

    PubMed

    Dubey, Jitender Prakash; Casey, Sarah Jane; Zajac, Anne Marie; Wildeus, Stephen Arthur; Lindsay, David Scott; Verma, Shiv Kumar; Oliveira, Solange; Kwok, Oliver Chun Hung; Su, Chunlei

    2014-12-01

    Alpacas are important to the economy of several countries. Little is known of Toxoplasma gondii infection in alpacas worldwide. In the present study, T. gondii was isolated and genetically characterized from alpacas for the first time. Alpacas (n = 16) and rams (n = 12) pastured on a farm in Virginia, USA, were examined at necropsy. Antibodies to T. gondii were determined by the modified agglutination test (MAT, 1:25) and found in 6 of 16 alpacas with titers of 1:100 (2 alpaca), 1:400 (2 alpacas), 1:800 (1 alpaca), and 1:1,600 (1 alpaca), and 5 of 12 rams in titers of 1:50 in one, 1:400 in one, 1:800 in one, 1:1,600 in one, and 1:3,200 in one. Tissues of all 16 alpacas were bioassayed in mice or in cats. Muscles (heart, skeletal muscle) of nine alpacas with MAT titers of 1:25 were fed to T. gondii-free cats; the cats did not shed oocysts. Viable T. gondii was isolated from tissues of two of six seropositive alpacas by bioassay in mice. Viable T. gondii was isolated from three of three seropositive sheep by bioassay in mice. Genotyping using cell-cultured tachyzoites revealed four genotypes, including one for ToxoDB PCR-RFLP genotype #2 (type III), one for genotype #3 (type II variant), one for genotype #170, and two for a new genotype designated as ToxoDB PCR-RFLP genotype #230. Thus, four of the five T. gondii isolates in the present study belonged to different genotypes. These results indicate a higher genetic diversity among T. gondii isolates circulating in the USA than previously realized.

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

    PubMed

    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.

  20. HLA-DQBl*0402 alleles polymorphisms detected in Javanese HIV patients with positive anti-Toxoplasma gondii IgM

    NASA Astrophysics Data System (ADS)

    Sari, Yulia; Haryati, Sri; Prasetyo, Afiono Agung; Hartono, Adnan, Zainal Arifin

    2017-02-01

    The human leukocyte antigen (HLA)-DQB1 gene polymorphisms may associated with the infection risk of Toxoplasma gondii in HIV patients. The HLA-DQB1*0402 in HIV-1-positive patients could be considered risk factors for developing neurological opportunistic infections, mainly Toxoplasma encephalitis. However, the HLA-DQB1*0402 gene polymorphisms status in the Javanese HIV patients is unknown. This study evaluated the prevalence of HLA-DQB*0402 alleles polymorphisms in Javanese HIV patients with positive anti-Toxoplasma gondii IgM status. Since 2009 our research group performing a molecular epidemiology of blood borne viruses in Central Java Indonesia, by collecting the epidemiological and clinical data from the high risk communities. All blood samples were screened for blood borne pathogens by serological and molecular assays including for HIV and Toxoplasma gondii. The genomic DNA was isolated from the whole blood samples. Genetic polymorphisms of HLA-DQB1*0402 alleles were detected with polymerase chain reaction-sequence-specific primers (PCR-SSPs) technique. The genotypes were defined according to generated fragment patterns in the agarose gel electrophoresis analysis of PCR products. All of the samples were tested at least in duplicate. HLA-DQB1*0402 alleles were detected in 20.8% (16/77) patients and not detected in all HIV positive samples with negative anti-Toxoplasma gondii IgM status (n= 200). The HLA-DQB1*0402 alleles polymorphisms were detected in Javanese HIV patients with positive anti-Toxoplasma gondii IgM. The polymorphisms found may have association with the infection risk of Toxoplasma gondii in HIV patients.

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

    PubMed

    Sroka, Jacek; Wójcik-Fatla, Angelina; Dutkiewicz, Jacek

    2006-01-01

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

  2. Toxoplasma gondii infection in marrow transplant recipients: a 20 year experience.

    PubMed

    Slavin, M A; Meyers, J D; Remington, J S; Hackman, R C

    1994-05-01

    Twelve of 3803 consecutive marrow allograft patients treated at this center over the past 20 years have had a post-transplant tissue diagnosis of toxoplasmosis: 10 at autopsy and 2 by brain biopsy. This infection was identified in none of 509 autologous marrow recipients. Occurrence of toxoplasmosis was 0.31 cases per 100 allogeneic transplants and 1.0 per 100 autopsies. An estimated 15% of allogeneic transplant recipients were seropositive for Toxoplasma gondii and 2% of seropositive patients developed toxoplasmosis. Pre-transplant serology was positive by both dye and agglutination tests in 11 infected patients tested. Sequential IgG, IgM, IgA, IgE antibody titers to T. gondii and the differential agglutination ratio were not helpful in diagnosing toxoplasmosis. Median day of clinical presentation was day 59 post-transplant (35-97 days) and of diagnosis, day 62 after transplant (37-143 days). Eleven patients had graft-versus-host disease (GVHD) of grades II-IV. All 12 patients died. Infection was diagnosed prior to death in only 16% of patients and contributed to death in at least 40%. Histopathology revealed tachyzoites of T. gondii most prevalent in brain (100%), heart (67%) and lungs (33%), and toxoplasma cysts alone in heart (33%) and lungs (22%). Toxoplasma infection was diagnosed in two patients receiving trimethoprim-sulfamethoxazole for Pneumocystis carinii pneumonia prophylaxis suggesting this was insufficient prophylaxis for toxoplasmosis. Toxoplasmosis appeared to occur by reactivation within the first 6 months after marrow transplant. Infection developed in patients who were seropositive for T. gondii pre-transplant, had received allogeneic marrow and had severe GVHD.

  3. Seroprevalence of Toxoplasma gondii and Neospora spp. Infections in Arab Horses, Southwest of Iran

    PubMed Central

    Tavalla, Mehdi; Sabaghan, Mohammad; Abdizadeh, Rahman; Khademvatan, Shahram; Rafiei, Abdollah; Razavi Piranshahi, Anahita

    2015-01-01

    Background: Because of the economic importance of the Arab race horses and also the role of Toxoplasma gondii and Neospora spp. in abortion and reproductive failure of these animals, we decided to perform this study. Objectives: We designed this study to investigate the seroprevalence of anti-Toxoplasma gondii and anti-Neospora spp. antibodies in Arab horses from 12 cities of Khuzestan province in southwest of Iran. Materials and Methods: From October 2009 to March 2011, a total of 235 blood samples were collected from jugular veins of Arab horses of different ages and genders from 12 cities of Khuzestan province. All the sera were tested for anti-Toxoplasma antibodies using the modified agglutination test (MAT) and the existence of anti-Neospora antibodies were tested using N-MAT for Neospora spp. Results: According to the MAT results, antibodies to T. gondii were found in 114 (48.5%) of 235 sera with titers of 1:20 in 84, 1:40 in 19, 1:80 in four, 1:160 in four, and 1:320 in three horses. According to the N-MAT results, antibodies to Neospora spp. were found in 47 (20%) of 235 sera with titers of 1:40 in 39, 1:80 in five, and 1:160 in three horses. We did not observe any statistically significant differences regarding age groups and genders between seropositive and seronegative horses for Neospora spp. using chi-square (χ2) test, but it seemed that anti-Toxoplasma antibodies were more prevalent in older horses (≥ 10 years old). Conclusions: The results indicated that Arab horses are exposed to these parasites in southwest of Iran. Further research is required to determine the genomic structures of these parasites in Arab horses in southwest of Iran. PMID:25834714

  4. Expression and Single-step Purification of GRA8 Antigen of Toxoplasma gondii in Escherichia coli

    PubMed Central

    Babaie, Jalal; Miri, Mandana; Sadeghiani, Ghazaleh; Zare, Mehrak; Khalili, Ghader; Golkar, Majid

    2011-01-01

    Diagnosis of Toxoplasma gondii (T.gondii) infection is of great medical importance especially for pregnant women and immunosuppressed patients. Numerous studies have shown that the recombinant production of several toxoplasma antigens, including dense granule antigens (GRAs) has a great potential as diagnostic reagents. Previous studies reported expression of amino terminal GRA8 protein in fusion with large tags. In the present study, we produced truncated GRA8 (GRA8), excluded from the signal peptide and C-terminal transmembrane domain, with a short fusion tag in Escherichia coli (E.coli). GRA8 was purified using an optimized single-step Immobilized Metal ion Affinity Chromatography (IMAC). The purity and yield of GRA8 was highest at pH = 9.25. At this pH, 13.6 mg of GRA8 was obtained with the purity of 97.97%. Immunogenicity of the protein was evaluated in Western blot analysis showing the serum sample from a rabbit immunized with GRA8 recognized a single antigen of T.gondii tachyzoite at the expected molecular weight of native GRA8. To diagnosis acute toxoplasma infection in pregnant women, an indirect immunoglobulin M (IgM) enzyme-linked immunosorbent assay (ELISA) was developed using GRA8 resulting in a test specificity and sensitivity of 97.1% and 60.6%, respectively. These results demonstrated that immunogenic GRA8 can be produced in fusion with a short tag and purified near to homogeneity using an optimized IMAC. GRA8-IgM-ELISA was useful for detection of acute toxoplasma infection. PMID:23407862

  5. First report of Toxoplasma gondii seroprevalence in pet parrots in China.

    PubMed

    Zhang, Xiao-Xuan; Zhang, Nian-Zhang; Tian, Wei-Peng; Zhou, Dong-Hui; Xu, Ying-Tian; Zhu, Xing-Quan

    2014-06-01

    Toxoplasmosis, caused by the obligate intracellular protozoan parasite Toxoplasma gondii, has become a serious public health problem worldwide. T. gondii can infect almost all warm-blooded animals, including parrots. However, little is known of T. gondii infection in parrots in China. Antibodies against T. gondii in 311 parrots including 202 Budgerigars (Melopsittacus undulatus), 26 Lovebirds (Agapornis sp.), 22 Cockatiels (Nymphicus hollandicus), and 61 Alexandrine Parakeets (Psittacula eupatria) in the cities of Beijing and Weifang in north China were tested using the modified agglutination test (MAT). Twenty-six (8.36%) out of 311 serum samples were positive for T. gondii at the cutoff of 1:5. Among the four species, a higher seroprevalence of T. gondii was found in Cockatiels (13.64%, 95% confidence interval [CI] 0.00-27.98), although the difference was not statistically significant (p=0.61). Seropositivity rates against T. gondii in male parrots (10.43%, 95% CI 5.74-15.12) were not statistically different from that in female parrots (6.08%, 95% CI 2.23-9.93, p=0.17). The seropositivity of T. gondii in parrots from Weifang and Beijing was 11.11% (95% CI 6.13-16.09) and 5.70% (95% CI 2.08-9.31), respectively. The seroprevalence varied in parrots of different age groups, ranging from 5.71% (95% CI 1.27-10.15) to 13.00% (95% CI 6.41-19.69), however, the difference among age groups was not statistically significant (p=0.12). The seroprevalence of T. gondii infection in parrots in summer (11.63%, 95% CI 6.84-16.42) was significantly higher than in spring (4.32%, 95% CI 0.94-7.70, p=0.02). The results of the present survey indicated that parrots in China are exposed to T. gondii. To our knowledge, this is the first report of T. gondii seroprevalence in parrots in China.

  6. Seroepidemiology of Toxoplasma gondii infection in psychiatric inpatients in a northern Mexican city

    PubMed Central

    Alvarado-Esquivel, Cosme; Alanis-Quiñones, Olga-Patricia; Arreola-Valenzuela, Miguel-Ángel; Rodríguez-Briones, Alfredo; Piedra-Nevarez, Luis-Jorge; Duran-Morales, Ehecatl; Estrada-Martínez, Sergio; Martínez-García, Sergio-Arturo; Liesenfeld, Oliver

    2006-01-01

    Background Patients with psychiatric disorders were found to show a high seroprevalence of Toxoplasma gondii infection. There is scarce information about the epidemiology of T. gondii infection in psychiatric patients 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 psychiatric patients in Durango City, Mexico. Seroprevalence in patients was compared with that obtained in a control population. Methods One hundred and thirty seven inpatients of a public psychiatric hospital and 180 controls were examined for the presence of IgG and IgM antibodies against T. gondii by enzyme-linked immunoassay (Diagnostic Automation Inc., Calabasas, CA, USA). The control population consisted of blood donors of a public blood bank and elderly persons attending a senior center in the same city. Age in controls (42 years +/- 20.2) was comparable with that of the psychiatric patients (43.7 years +/-13.8) (p = 0.42). Socio-demographic, clinical and behavioral characteristics from the patients were also obtained. Results Anti-T. gondii IgG antibodies indicating latent infection with T. gondii was found in 25 (18.2%) of 137 psychiatric inpatients and 16 (8.9%) of 180 controls (p = 0.02). Ten (26.3%) of 38 schizophrenic patients had latent infection and this prevalence was also significantly higher than that observed in controls (p = 0.005). Prevalence of anti-T. gondii IgM antibodies was comparable among patients and controls (4.4% vs 2.2%, respectively, p = 0.22). Multivariate analysis showed that T. gondii infection in inpatients was positively associated with sexual promiscuity (adjusted OR = 15.8; 95% CI: 3.8–64.8), unwashed raw fruit consumption (adjusted OR = 5.19; 95% CI: 2.3–11.3), and a history of surgery (adjusted OR = 6.5; 95% CI: 2.6–16), and negatively associated with lamb meat consumption (adjusted OR = 0.26; 95% CI: 0.10–0.63). Conclusion In

  7. Molecular and biological characterisation of Toxoplasma gondii isolates from free-range chickens from Guyana, South America identified several unique and common parasite genotypes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The prevalence of Toxoplasma gondii in free-ranging chickens (Gallus domesticus) is a good indicator of the prevalence of T. gondii oocysts in the soil because chickens feed from the ground. The prevalence of T. gondii in 76 free-range chickens from Guyana, South America was determined. Antibodies t...

  8. Seroepidemiology of infection with Toxoplasma gondii in patients with vision and hearing impairments, cancer, HIV, or undergoing hemodialysis in Durango, Mexico

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Toxoplasma gondii infection may cause a variety of symptoms involving virtually all organs. Little is known of the epidemiology of T. gondii infection in different patient groups in Mexico. We sought to determine the prevalence of T. gondii infection and associated epidemiological characteristics in...

  9. Genetic diversity among capybara (Hydrochaeris hydrochaeris) isolates of Toxoplasma gondii from Brazil.

    PubMed

    Yai, Lucia E O; Ragozo, Alessandra M A; Soares, Rodrigo M; Pena, Hilda F J; Su, C; Gennari, Solange M

    2009-06-10

    Recent studies indicate that Toxoplasma gondii isolates of many domestic hosts from Brazil are genetically and biologically different from T. gondii isolates from USA and Europe. However, little is known about genetics of T. gondii isolates from wild mammals in Brazil. In this study, genotypes of 36 T. gondii isolates from capybaras (Hydrochaeris hydrochaeris) from six counties in São Paulo state, Brazil, were determined. Sixteen genotypes were identified using 11 genetic markers including SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, Apico and CS3. No classical clonal Type I and Type II isolates were found, confirming other findings that these lineages are rare in Brazil. Eight of these 36 isolates were grouped into the common clonal lineages in Brazil, previously designed as Types BrI, BrII and BrIII. Seven of the 16 genotypes were reported for the first time in this study. Three of the 36 isolates showed mixed infections. Analysis of mortality rates in infected mice indicated that Type BrI is highly virulent, Type BrII is intermediately virulent and Type BrIII is non-virulent, which is in agreement with previous report. The allele types at the CS3 locus are strongly linked to mouse-virulence of the parasite. These genotyping results support previous findings that the T. gondii population is highly diverse in Brazil.

  10. iTRAQ-based differential proteomic analysis in Mongolian gerbil brains chronically infected with Toxoplasma gondii.

    PubMed

    Lv, Lin; Wang, Yapei; Feng, Weili; Hernandez, Jorge A; Huang, Wanyi; Zheng, Yuxiang; Zhou, Xue; Lv, Shumei; Chen, Yajun; Yuan, Zi-Guo

    2017-03-17

    The aim of our study was to detect differentially regulated proteins and specific signaling pathways in Mongolian gerbil brains during chronic Toxoplasma gondii (T.gondii) PRU strain infection. We use a iTRAQ-based strategy to detecte 4935 proteins, out of which 110 proteins were differentially expressed (>/=2.0-fold, p value <0.05) when the brain of gerbils infected with T.gondii was compared to control brain tissues. We confirmed the authenticity and the accuracy of iTRAQ results through quantitative real-time PCR and western blot (WB), which was consistent with mass spectrometry analysis. Pathway analysis and GO (Gene Ontology) annotations indicated the deregulation of several pathways related to immune response, metabolism and neurological processes, like neuronal growth and neurotransmitter transport. Through the iTRAQ-based strategy, we obtained a comparative proteome profile of brain tissues from Mongolian gerbils with chronic infection of T.gondii. Several differentially expressed proteins involved in neurological pathways, like Parvalbumin, Drebrin or Synaptotagmin, can be further investigated to enhance our understanding of central nervous system (CNS) injury caused by T.gondii.

  11. Cloning, expression and immunoreactivity of recombinant Toxoplasma gondii GRA5 protein

    PubMed Central

    Arab-Mazar, Zahra; Fallahi, Shirzad; Koochaki, Ameneh; Mirahmadi, Hadi; Tabaei, Seyyed Javad Seyyed

    2016-01-01

    Background and Objectives: Toxoplasma gondii is an obligatory intracellular parasite which causes severe diseases in the fetus of pregnant women and immunocopmromised patients. Serological tests based on recombinant protein are one of the main diagnosis methods for the detection of specific antibodies in serum samples. Dense granule antigenic proteins derived from T. gondii (TgGRAs) are potential antigens for the development of diagnostic tools. Materials and Methods: DNA was extracted from T. gondii (RH-strain) tachyzoites and PCR reaction was done using corresponding primers for GRA5 antigen. The PCR product was purified and ligated into pTG19-t vector and then subcloned into XhoI and BamHI digested pGEX6p-1 expression vector. Recombinant plasmid was transformed into E. coli (BL21 DE3) and induced by 1mM IPTG and analyzed by 15% SDS-PAGE. Expressed protein was confirmed by western blot analysis. Results: There was no difference among the sequences of T. gondii GRA5 gene from different isolates. The recombinant plasmid pGEX-6p-1/GRA5 induced by IPTG was expressed in E. coli. It was a GST fusion protein and could react with human positive sera analyzed by western blot. Conclusion: The GRA5 gene of T. gondii isolates is highly conservative. This antigen as a recombinant protein was successfully expressed in E. coli, which showed high immunoreactivity. PMID:28149494

  12. Replication of Toxoplasma gondii in chicken erythrocytes and thrombocytes compared to macrophages.

    PubMed

    Malkwitz, Irene; Berndt, Angela; Zhang, Runhui; Daugschies, Arwid; Bangoura, Berit

    2017-01-01

    Toxoplasma (T.) gondii is able to infect various cell types in different hosts. The replication of this parasite within different peripheral mononuclear blood cell populations in chicken has not yet been fully understood. Aim of the present study was to investigate the impact of chicken erythrocytes and thrombocytes as potential host cells for T. gondii. Cultures of primary avian erythrocytes and thrombocytes were inoculated with tachyzoites of T. gondii type II strain ME49. Parasite replication was detected by a quantitative real-time PCR at different times postinoculation until 24 or 48 h, respectively, displaying long-term investigations for the chosen cultures. The parasite replication curve showed a continuous decrease of parasite stages in erythrocytes and thrombocytes. Observations by light microscopy showed massive destruction for both cell populations. Few macrophages in between the infected thrombocytes were viable during the investigation period and showed internalised tachyzoites by confocal laser scanning microscopy. These findings show that T. gondii is not capable of replication in chicken erythrocytes and thrombocytes; therefore, both cannot be considered as potential host cells. In further consequence, monocyte-derived macrophages seem to be the key to the dissemination mechanisms for T. gondii in chicken.

  13. Toxoplasma gondii peptide ligands open the gate of the HLA class I binding groove

    PubMed Central

    McMurtrey, Curtis; Trolle, Thomas; Sansom, Tiffany; Remesh, Soumya G; Kaever, Thomas; Bardet, Wilfried; Jackson, Kenneth; McLeod, Rima; Sette, Alessandro; Nielsen, Morten; Zajonc, Dirk M; Blader, Ira J; Peters, Bjoern; Hildebrand, William

    2016-01-01

    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 cells and characterize the peptide ligands using LCMS. We identify 195 T. gondii encoded ligands originating from both secreted and cytoplasmic proteins. Surprisingly, T. gondii ligands are significantly longer than uninfected host ligands, and these longer pathogen-derived peptides maintain a canonical 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. DOI: http://dx.doi.org/10.7554/eLife.12556.001 PMID:26824387

  14. Toxoplasma gondii Infection in Immunocompromised Patients: A Systematic Review and Meta-Analysis

    PubMed Central

    Wang, Ze-Dong; Liu, Huan-Huan; Ma, Zhan-Xi; Ma, Hong-Yu; Li, Zhong-Yu; Yang, Zhi-Bin; Zhu, Xing-Quan; Xu, Bin; Wei, Feng; Liu, Quan

    2017-01-01

    Toxoplasma gondii has been suggested as an important opportunistic pathogen in immunocompromised patients. We conducted a global meta-analysis to assess the prevalence and odds ratios (ORs) of T. gondii infection in immunocompromised individuals. Electronic databases were reviewed for T. gondii infection in HIV/AIDS patients, cancer patients, and transplant recipients, and meta-analyses were conducted to calculate overall estimated prevalence and ORs using random or fixed-effects models. Totally, 72 eligible studies were included. The estimated pooled prevalence of T. gondii infection in immunocompromised patients and the control was 35.9 and 24.7% (p < 0.001), with an OR of 2.24, i.e., 42.1 and 32.0% for HIV/AIDS patients and the control (p < 0.05), 26.0 and 12.1% for cancer patients and the control (p < 0.001), and 42.1 and 34.5% for transplant recipients and the control (p > 0.05), whose estimated pooled ORs were 1.92 (95% CI, 1.44–2.55), 2.89 (95% CI, 2.36–3.55), and 1.51 (95% CI, 1.16–1.95), respectively. This study is the first to demonstrate that the immunocompromised patients are associated with higher odds of T. gondii infection, and appropriate prevention and control measures are highly recommended for these susceptible populations. PMID:28337191

  15. Toxoplasma gondii Myocarditis after Adult Heart Transplantation: Successful Prophylaxis with Pyrimethamine

    PubMed Central

    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

  16. Toxoplasma gondii infection can induce retinal DNA damage: an experimental study

    PubMed Central

    El-Sayed, Nagwa Mostafa; Aly, Eman Mohamed

    2014-01-01

    AIM To detect whether Toxoplasma gondii (T. gondii) infection of mice can induce retinal DNA damage. METHODS A total of 20 laboratory-bred male Swiss albino mice were used and divided into four groups: control group (non-infected animals); T. gondii infected group; immunosuppressed infected group; and infected group treated with sulfadiazine and pyrimethamine. Mice eyes were collected 6wk post infection and retinas were obtained. Each retina was immediately processed for comet assay and the frequency of tailed nuclei (DNA damage) was calculated. In addition, retinal DNA damage was revealed by various comet assay parameters that were provided by the image analysis software including tail length, percentage of DNA in the tail, percentage of tailed cells and tail moment. RESULTS The obtained results showed that T. gondii infection induced a statistically significant increase in the frequency of tailed nuclei, tail length, percentage of DNA in the tail, and tail moment in mice retinal cells compared to the control group (which showed some degree of DNA damage). In immunosuppressed infected group, retinal DNA damage was severing and there was significant increase in various comet assay parameters compared to both control and infected groups. After treatment with sulfadiazine and pyrimethamine, retinal DNA damage decreased and all comet assay parameters showed a statistical significant decrease compared to infected groups. CONCLUSION T. gondii infection can induce DNA damage in mice retinal cells. PMID:24967186

  17. Seroprevalence of Toxoplasma gondii in Dairy Cattle with Reproductive Problems in Sudan

    PubMed Central

    Elfahal, Abdelghafar M.; Elhassan, Amira M.; Hussien, Mohammed O.; Enan, Khalid A.; Musa, Azza B.; El Hussein, Abdelrahim M.

    2013-01-01

    Toxoplasmosis, caused by Toxoplasma gondii, is one of the most common parasitic infections of humans and other warm-blooded animals in most parts of the world. The disease is common among sheep and goats and it is recognized as one of the major causes of reproductive failure in these animals. Cattle, on the other hand, can be infected, but abortion or perinatal mortality has not been recorded. This survey was carried out to study the prevalence of this disease in cattle in Khartoum and Gazira States (Sudan). 181 sera samples collected from dairy cattle with reproductive problems were assayed for antibodies to T. gondii by ELISA. The prevalence rate of T. gondii antibodies in cattle at herd level was 44.8% (13/29). Herd level infection rates were 50% and 33.3% in Khartoum and Gazira States, respectively. The overall prevalence of T. gondii at individual level in both states was 13.3% (24/181). The prevalence was 12.7% (17/134), was 14.9% (7/47) in Khartoum and Gazira State, respectively. There was significantly higher (P < 0.05) prevalence of T. gondii antibodies in the age group less than one year old (36.4%) than in other age groups and in males (30.8%) than in females (11.9%) while no significant relationship was discerned regarding breed, location, season, or signs of reproductive disease. PMID:24171116

  18. Improved Techniques for Endogenous Epitope Tagging and Gene Deletion in Toxoplasma gondii

    PubMed Central

    Upadhya, Rajendra; Kim, Kami; Hogue-Angeletti, Ruth; Weiss, Louis M

    2011-01-01

    Toxoplasma gondii is an excellent model organism for studies on the biology of the Apicomplexa due to its ease of in vitro cultivation and genetic manipulation. Large-scale reverse genetic studies in T. gondii have, however, been difficult due to the low frequency of homologous recombination. Efforts to ensure homologous recombination have necessitated engineering long flanking regions in the targeting construct. This requirement makes it difficult to engineer chromosomally targeted epitope tags or gene knock out constructs only by restriction enzyme mediated cloning steps. To address this issue we employed multisite Gateway® recombination techniques to generate chromosomal gene manipulation targeting constructs. Incorporation of 1.5 to 2.0 kb flanking homologous sequences in PCR generated targeting constructs resulted in 90% homologous recombination events in wild type T. gondii (RH strain) as determined by epitope tagging and target gene deletion experiments. Furthermore, we report that split marker constructs were equally efficient for targeted gene disruptions using the T. gondii UPRT gene locus as a test case. The methods described in this paper represent an improved strategy for efficient epitope tagging and gene disruptions in T. gondii. PMID:21352857

  19. Seroprevalence of Toxoplasma gondii in wild boars, red deer and roe deer in Poland.

    PubMed

    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.

  20. Pantothenic Acid Biosynthesis in the Parasite Toxoplasma gondii: a Target for Chemotherapy

    PubMed Central

    Mageed, Sarmad N.; Cunningham, Fraser; Hung, Alvin Wei; Silvestre, Hernani Leonardo; Wen, Shijun; Blundell, Tom L.; Abell, Chris

    2014-01-01

    Toxoplasma gondii is a major food pathogen and neglected parasitic infection that causes eye disease, birth defects, and fetal abortion and plays a role as an opportunistic infection in AIDS. In this study, we investigated pantothenic acid (vitamin B5) biosynthesis in T. gondii. Genes encoding the full repertoire of enzymes for pantothenate synthesis and subsequent metabolism to coenzyme A were identified and are expressed in T. gondii. A panel of inhibitors developed to target Mycobacterium tuberculosis pantothenate synthetase were tested and found to exhibit a range of values for inhibition of T. gondii growth. Two inhibitors exhibited lower effective concentrations than the currently used toxoplasmosis drug pyrimethamine. The inhibition was specific for the pantothenate pathway, as the effect of the pantothenate synthetase inhibitors was abrogated by supplementation with pantothenate. Hence, T. gondii encodes and expresses the enzymes for pantothenate synthesis, and this pathway is essential for parasite growth. These promising findings increase our understanding of growth and metabolism in this important parasite and highlight pantothenate synthetase as a new drug target. PMID:25049241

  1. A Novel Polyclonal Antiserum against Toxoplasma gondii Sodium Hydrogen Exchanger 1.

    PubMed

    Xiao, Bin; Kuang, Zhenzhan; Zhan, Yanli; Chen, Daxiang; Gao, Yang; Li, Ming; Luo, Shuhong; Hao, Wenbo

    2016-02-01

    The sodium hydrogen exchanger 1 (NHE1), which functions in maintaining the ratio of Na(+) and H(+) ions, is widely distributed in cell plasma membranes. It plays a prominent role in pH balancing, cell proliferation, differentiation, adhesion, and migration. However, its exact subcellular location and biological functions in Toxoplasma gondii are largely unclear. In this study, we cloned the C-terminal sequence of T. gondii NHE1 (TgNHE1) incorporating the C-terminal peptide of NHE1 (C-NHE1) into the pGEX4T-1 expression plasmid. The peptide sequence was predicted to have good antigenicity based on the information obtained from an immune epitope database. After induction of heterologous gene expression with isopropyl-b-D-thiogalactoside, the recombinant C-NHE1 protein successfully expressed in a soluble form was purified by glutathione sepharose beads as an immunogen for production of a rabbit polyclonal antiserum. The specificity of this antiserum was confirmed by western blotting and immunofluorescence. The antiserum could reduce T. gondii invasion into host cells, indicated by the decreased TgNHE1 expression in T. gondii parasites that were pre-incubated with antiserum in the process of cell entry. Furthermore, the antiserum reduced the virulence of T. gondii parasites to host cells in vitro, possibly by blocking the release of Ca(2+). In this regard, this antiserum has potential to be a valuable tool for further studies of TgNHE1.

  2. Toxoplasma gondii peptide ligands open the gate of the HLA class I binding groove.

    PubMed

    McMurtrey, Curtis; Trolle, Thomas; Sansom, Tiffany; Remesh, Soumya G; Kaever, Thomas; Bardet, Wilfried; Jackson, Kenneth; McLeod, Rima; Sette, Alessandro; Nielsen, Morten; Zajonc, Dirk M; Blader, Ira J; Peters, Bjoern; Hildebrand, William

    2016-01-29

    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 cells and characterize the peptide ligands using LCMS. We identify 195 T. gondii encoded ligands originating from both secreted and cytoplasmic proteins. Surprisingly, T. gondii ligands are significantly longer than uninfected host ligands, and these longer pathogen-derived peptides maintain a canonical 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.

  3. Seroprevalence of Toxoplasma gondii and Neospora caninum in dairy goats from Romania.

    PubMed

    Iovu, Anamaria; Györke, Adriana; Mircean, Viorica; Gavrea, Raluca; Cozma, Vasile

    2012-05-25

    Little information is available about the seroprevalence of Toxoplasma gondii and Neospora caninum infections in goats in Romania and even in Europe. During 2007-2010, 735 serum samples were collected from dairy goats located in 4 historical regions (Crişana, Maramureş, Transylvania and Muntenia) of Romania. Sera were analyzed for T. gondii and N. caninum antibodies (IgG type) by enzyme-linked immunosorbent assay (ELISA) using two commercial kits (Chekit Toxotest Antibody ELISA and Chekit Neospora caninum Antibody ELISA; Idexx-Bommeli, Switzerland). Three hundred and eighty-eight out of 735 (52.8%) goats presented T. gondii antibodies and 12 out of 512 (2.3%) goats had N. caninum antibodies. The high seroprevalence of T. gondii suggests that infection with this parasite is common in dairy goats in Romania, and less common the infection with N. caninum. This is the first time that infection with N. caninum in goats has been reported in Romania and the first extended study on seroepidemiology of T. gondii.

  4. Toxoplasma gondii infection in dairy ewes: Vertical transmission and influence on milk production and reproductive performance.

    PubMed

    Klauck, Vanderlei; Pazinato, Rafael; Radavelli, Willian M; Custódio, Edimar; Bianchi, Anderson E; Camillo, Giovana; Cezar, Alfredo S; Vogel, Fernanda F; Tonin, Alexandre A; Ferreira, Rogério; Stefani, Lenita M; Da Silva, Aleksandro S

    2016-10-01

    The present study aimed to evaluate the transmission of toxoplasmosis (vertical and venereal) and its influence on milk production and reproductive problems of Lacaune sheep seropositives for Toxoplasma gondii. Males and females were serologically selected using indirect immunofluorescence method in three steps of the study. Step 1: In order to evaluate the influence of toxoplasmosis on milk production, the volume of milk produced by 40 sheep (22 seronegatives and 18 seropositives for T. gondii) was weekly measured throughout the lactation period. There were no significant differences between these two groups; in other words, toxoplasmosis did not affect milk production. Step 2: In order to assess T. gondii venereal transmission, five samples of semen from seropositive rams (n = 5) were tested by endpoint and real time PCR with two days of interval; however, these semen samples were PCR negatives for T. gondii. Step 3: To evaluate reproductive problems, 12 seropositive animals out of a flock of 68 pregnant ewes showed signs of reproductive problems, such as abortion or fetal resorption. T. gondii transplacental transmission was evaluated on blood drawn from newborn lambs (n = 41), and their respective seropositive mothers (n = 30) after single, double or triple births. Serological tests showed that 65.8% of the lambs had antibodies against this protozoan, indicating a high transmission from ewe to fetus during pregnancy. Therefore, it is concluded that toxoplasmosis in sheep may impair reproduction with a high percentage of vertical transmission.

  5. Molecular detection and genetic characterization of Toxoplasma gondii infection in sika deer (Cervus nippon) in China.

    PubMed

    Cong, Wei; Qin, Si-Yuan; Meng, Qing-Feng; Zou, Feng-Cai; Qian, Ai-Dong; Zhu, Xing-Quan

    2016-04-01

    The objective of the present study was to investigate the prevalence and genetic characterization of Toxoplasma gondii infection in sika deer in China. During August 2014 to November 2014, a total of 450 tissue samples coming from 150 sika deer were collected to detect the T. gondii B1 gene using a nested PCR, and the positive samples were genotyped at 11 genetic markers (SAG1, 5'- and 3'-SAG2, alternative SAG2, SAG3, BTUB, GRA6, L358, PK1, c22-8, c29-2, and Apico) using multilocus polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technology. Seventeen of 150 sika deer (11.33%) were tested positive by nested PCR. Six DNA samples from the 17 positive samples were completely typed, in which 4 samples from lung tissues, and 2 from muscular tissues, were identified as ToxoDB Genotype #9 (http://toxodb.org/toxo/). The results of the present study revealed the existence of T. gondii infection in sika deer in China, which provided the information of T. gondii genetic diversity in this host species. This study also indicated that ToxoDB Genotype #9 has a wide distribution in sika deer that could be potential reservoirs for T. gondii transmission, which may pose a threat to human health.

  6. Low Seroprevalence of Leishmania infantum and Toxoplasma gondii in the Horse Population in Israel.

    PubMed

    Aharonson-Raz, Karin; Baneth, Gad; Lopes, Ana Patrícia; Brancal, Hugo; Schallig, Henk; Cardoso, Luís; Steinman, Amir

    2015-12-01

    A cross-sectional investigation was done on the seroprevalence of Leishmania infantum and Toxoplasma gondii infection among apparently healthy horses in Israel. This survey included 383 horses distributed in 22 farms throughout Israel during the years 2011-2013. Serum samples were tested for the presence of immunoglobulin G (IgG) antibodies using the direct agglutination test (DAT) specific to Leishmania and by the modified agglutination test (MAT) for the presence of IgG antibodies to T. gondii. Low seroprevalences were detected for both L. infantum and T. gondii in the horse population in Israel; of the 338 horses tested, 6 (1.4%) were found to be seropositive for L. infantum and 11 (2.5%) for T. gondii, with no significant association between seroprevalence and demographic/environmental factors. An ongoing geographical expansion of L. infantum, previously reported in humans and dogs in Israel, was also supported by our results in horses. Here we present evidence of exposure of horses to L. infantum and T. gondii in Israel. Continuous seroprevalence surveillance in horses, such as the one performed in this study, might further elucidate the eco-epidemiology of these two important zoonotic parasites in this country.

  7. Toxoplasma gondii infection blocks the development of allergic airway inflammation in BALB/c mice.

    PubMed

    Fenoy, I; Giovannoni, M; Batalla, E; Martin, V; Frank, F M; Piazzon, I; Goldman, A

    2009-02-01

    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 orofaecal and foodborne microbes such as Toxoplasma gondii. Infection with T. gondii induces a strong cell-mediated immunity with a highly polarized T helper type 1 (Th1) response in early stages of infection. Using a well-known murine model of allergic lung inflammation, we sought to investigate whether T. gondii infection could modulate the susceptibility to develop respiratory allergies. Both acute and chronic infection with T. gondii before allergic sensitization resulted in a diminished allergic inflammation, as shown by a decrease in bronchoalveolar lavage (BAL) eosinophilia, mononuclear and eosinophil cell infiltration around airways and vessels and goblet cell hyperplasia. Low allergen-specific immunoglobulin (Ig)E and IgG1 and high levels of allergen-specific IgG2a serum antibodies were detected. A decreased interleukin (IL)-4 and IL-5 production by lymph node cells was observed, while no antigen-specific interferon-gamma increase was detected. Higher levels of the regulatory cytokine IL-10 were found in BAL from infected mice. These results show that both acute and chronic parasite infection substantially blocked development of airway inflammation in adult BALB/c mice. Our results support the hypothesis that T. gondii infection contributes to protection against allergy in humans.

  8. Production, Characterization and Applications for Toxoplasma gondii-Specific Polyclonal Chicken Egg Yolk Immunoglobulins

    PubMed Central

    Ferreira Júnior, Álvaro; Santiago, Fernanda M.; Silva, Murilo V.; Ferreira, Flávia B.; Macêdo Júnior, Arlindo G.; Mota, Caroline M.; Faria, Matheus S.; Filho, Hercílio H. Silva; Silva, Deise A. O.; Cunha-Júnior, Jair P.; Mineo, José R.; Mineo, Tiago W. P.

    2012-01-01

    Background Toxoplasma gondii may cause abortions, ocular and neurological disorders in warm-blood hosts. Immunized mammals are a wide source of hyperimmune sera used in different approaches, including diagnosis and the study of host-parasite interactions. Unfortunately, mammalian antibodies present limitations for its production, such as the necessity for animal bleeding, low yield, interference with rheumatoid factor, complement activation and affinity to Fc mammalian receptors. IgY antibodies avoid those limitations; therefore they could be an alternative to be applied in T. gondii model. Methodology/Principal Findings In this study we immunized hens with soluble tachyzoite antigens of T. gondii (STAg) and purified egg yolk antibodies (IgY) by an inexpensive and simple method, with high yield and purity degree. IgY anti-STAg antibodies presented high avidity and were able to recognize a broad range of parasite antigens, although some marked differences were observed in reactivity profile between antibodies produced in immunized hens and mice. Interestingly, IgY antibodies against Neospora caninum and Eimeria spp. did not react to STAg. We also show that IgY antibodies were suitable to detect T. gondii forms in paraffin-embedded sections and culture cell monolayers. Conclusions/Significance Due to its cost-effectiveness, high production yield and varied range of possible applications, polyclonal IgY antibodies are useful tools for studies involving T. gondii. PMID:22808150

  9. Strain hypothesis of Toxoplasma gondii infection on the outcome of human diseases

    PubMed Central

    Xiao, Jianchun; Yolken, Robert H.

    2015-01-01

    The intracellular protozoan Toxoplasma gondii is an exceptionally successful food- and waterborne parasite that infects approximately 1 billion people worldwide. Genotyping of T. gondii isolates from all continents revealed a complex population structure. Recent research supports the notion that T. gondii genotype may be associated with disease severity. Here, we (1) discuss molecular and serological approaches for designation of T. gondii strain type, (2) overview the literatures on the association of T. gondii strain type and the outcome of human disease, and (3) explore possible mechanisms underlying these strain specific pathology and severity of human toxoplasmosis. Although no final conclusions can be drawn, it is clear that virulent strains (e. g. strains containing type I or atypical alleles) are significantly more often associated with increased frequency and severity of human toxoplasmosis. The significance of highly virulent strains can cause severe diseases in immunocompetent patients and might implicated in brain disorders such as schizophrenia should led to reconsideration of toxoplasmosis. Further studies that combine parasite strain typing and human factor analysis (e.g. immune status and genetic background) are required for better understanding of human susceptibility or resistance to toxoplasmosis. PMID:25600911

  10. ISOLATION OF TOXOPLASMA GONDII FROM GOATS FROM BRAZIL

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Goats are economically important in many countries and little is known of caprine toxoplasmosis in Brazil. Antibodies to T. gondii were assayed in the sera of 143 goats from 3 Brazilian States, using modified agglutination test (MAT titer =1:25); 46 (32.2%) tested positive. Samples of brain, heart, ...

  11. Oxidative stress generated during monensin treatment contributes to altered Toxoplasma gondii mitochondrial function

    PubMed Central

    Charvat, Robert A.; Arrizabalaga, Gustavo

    2016-01-01

    The ionophore monensin displays potent activities against several coccidian parasites of veterinary and medical importance including the opportunistic pathogen of humans, Toxoplasma gondii. While monensin is used widely in animals, toxicity impedes its use in humans. Nonetheless, given its potency, understanding its mode of action would reveal vulnerable aspects of the parasite that can be exploited for drug development. We previously established that monensin induces Toxoplasma to undergo cell cycle arrest and an autophagy-like cell death. Interestingly, these effects are dependent on the mitochondrion-localized TgMSH-1 protein, suggesting that monensin disrupts mitochondrial function. We demonstrate that monensin treatment results in decreased mitochondrial membrane potential and altered morphology. These effects are mitigated by the antioxidant compound N-acetyl-cysteine suggesting that monensin causes an oxidative stress, which was indeed the case based on direct detection of reactive oxygen species. Moreover, over-expression of the antioxidant proteins glutaredoxin and peroxiredoxin 2 protect Toxoplasma from the deleterious effects of monensin. Thus, our studies show that the effects of monensin on Toxoplasma are due to a disruption of mitochondrial function caused by the induction of an oxidative stress and implicate parasite redox biology as a viable target for the development of drugs against Toxoplasma and related pathogenic parasites. PMID:26976749

  12. Effects of (+)-usnic acid and (+)-usnic acid-liposome on Toxoplasma gondii.

    PubMed

    Si, Kaiwei; Wei, Linlin; Yu, Xiaozhuo; Wu, Feng; Li, Xiaoqi; Li, Chen; Cheng, Yanbin

    2016-07-01

    Toxoplasma gondii pathogen is a threat to human health that results in economic burden. Unfortunately, there are very few high-efficiency and low-toxicity drugs for toxoplasmosis in the clinic. (+)-Usnic acid derived from lichen species has been reported to have anti-inflammatory, antibacterial, anti-parasitology, and even anti-cancer activities. Herein, the systematic effect of (+)-usnic acid and (+)-usnic acid-liposome on toxoplasma were studied in vitro and in vivo. The viability of toxoplasma tachyzoite was assayed with trypan blue and Giemsa staining; while the invasive capability of tachyzoite to cardiofibroblasts was detected using Giemsa staining. The survival time of mice and the changes in tachyzoite ultrastructure were studied in vivo. The results showed that (+)-usnic acid inhibited the viability of tachyzoite; pretreatment with (+)-usnic acid significantly decreased the invasion of tachyzoite to cardiofibroblasts in vitro; (+)-usnic acid and (+)-usnic acid-liposome extensively prolonged the survival time of mice about 90.9% and 117%, respectively; and improved the ultrastructural changes of tachyzoite, especially in dense granules, rhoptries, endoplasmic reticulum, mitochondria and other membrane organelles. In summary, these results demonstrate that (+)-usnic acid and (+)-usnic acid-liposome with low toxicity have an inhibitory effect on the viability of toxoplasma tachyzoite, and mainly destructed membrane organelles which are connected with the virulence of toxoplasma. These findings provide the basis for further study and development of usnic acid as a potential agent for treating toxoplasmosis.

  13. Optimization of the cryopreservation of biological resources, Toxoplasma gondii tachyzoites, using flow cytometry.

    PubMed

    Mzabi, Alexandre; Escotte-Binet, Sandie; Le Naour, Richard; Ortis, Naïma; Audonnet, Sandra; Dardé, Marie-Laure; Aubert, Dominique; Villena, Isabelle

    2015-12-01

    The conservation of Toxoplasma gondii strains isolated from humans and animals is essential for conducting studies on Toxoplasma. Conservation is the main function of the French Biological Toxoplasma Resource Centre (BRC Toxoplasma, France, http://www.toxocrb.com/). In this study, we have determined the suitability of a standard cryopreservation methodology for different Toxoplasma strains using the viability of tachyzoites assayed by flow cytometry with dual fluorescent labelling (calcein acetoxymethyl ester and propidium iodide) of tachyzoites. This method provides a comparative quantitative assessment of viability after thawing. The results helped to define and refine quality criteria before tachyzoite cryopreservation and optimization of the cryopreservation parameters. The optimized cryopreservation method uses a volume of 1.0 mL containing 8 × 10(6) tachyzoites, in Iscove's Modified Dulbecco's Medium (IMDM) containing 10% foetal calf serum (FCS). The cryoprotectant additive is 10% v/v Me2SO without incubation. A cooling rate of ∼1 °C/min to -80 °C followed, after 48 h, by storage in liquid nitrogen. Thawing was performed using a 37 °C water bath that produced a warming rate of ∼100 °C/min, and samples were then diluted 1:5 in IMDM with 5% FCS, and centrifuged and resuspended for viability assessment.

  14. Oxidative stress generated during monensin treatment contributes to altered Toxoplasma gondii mitochondrial function.

    PubMed

    Charvat, Robert A; Arrizabalaga, Gustavo

    2016-03-15

    The ionophore monensin displays potent activities against several coccidian parasites of veterinary and medical importance including the opportunistic pathogen of humans, Toxoplasma gondii. While monensin is used widely in animals, toxicity impedes its use in humans. Nonetheless, given its potency, understanding its mode of action would reveal vulnerable aspects of the parasite that can be exploited for drug development. We previously established that monensin induces Toxoplasma to undergo cell cycle arrest and an autophagy-like cell death. Interestingly, these effects are dependent on the mitochondrion-localized TgMSH-1 protein, suggesting that monensin disrupts mitochondrial function. We demonstrate that monensin treatment results in decreased mitochondrial membrane potential and altered morphology. These effects are mitigated by the antioxidant compound N-acetyl-cysteine suggesting that monensin causes an oxidative stress, which was indeed the case based on direct detection of reactive oxygen species. Moreover, over-expression of the antioxidant proteins glutaredoxin and peroxiredoxin 2 protect Toxoplasma from the deleterious effects of monensin. Thus, our studies show that the effects of monensin on Toxoplasma are due to a disruption of mitochondrial function caused by the induction of an oxidative stress and implicate parasite redox biology as a viable target for the development of drugs against Toxoplasma and related pathogenic parasites.

  15. Seroprevalence of Toxoplasma gondii in North-eastern Atlantic harbor seal (Phoca vitulina vitulina) and grey seal (Halichoerus grypus).

    PubMed

    Cabezón, O; Hall, A J; Vincent, C; Pabón, M; García-Bocanegra, I; Dubey, J P; Almería, S

    2011-06-30

    Antibodies to Toxoplasma gondii 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) were found in 14 (13.6%; IC(95%): 7.0-20.2) of 103 seals tested, with titres of 1:25 in 13 seals and 1:50 in 1 seal. Seroprevalence against T. gondii (MAT 1:25 or higher) was significantly higher in grey seals (23.4%) compared to harbor seals (5.4%). No significant differences were found between seroprevalence against T. gondii and sex, age or geographical locations. These results show natural exposure of European harbor and grey seals to T. gondii oocysts in the Atlantic Ocean. To the best of our knowledge, this is the first serological survey of T. gondii in European grey and harbor seals.

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

    PubMed

    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.

  17. Toxoplasma gondii in Capybara (Hydrochaeris hydrochaeris) antibodies and DNA detected by IFAT and PCR.

    PubMed

    Truppel, Jessé Henrique; Reifur, Larissa; Montiani-Ferreira, Fabiano; Lange, Rogério Ribas; de Castro Vilani, Ricardo Guilherme D'Otaviano; Gennari, Solange Maria; Thomaz-Soccol, Vanete

    2010-06-01

    Toxoplasmosis is considered nowadays as one of the most important foodborne diseases in the world. One of the emerging risks in acquiring infection with Toxoplasma gondii is the increasing popularity of wild animals and game meat. Capybara (Hydrochaeris hydrochaeris) is the world's largest extant rodent and is used for human consumption in many areas of South America, and in case it carries T. gondii cysts, it may act as a source of infection. In the present study, we detected infection with T. gondii in capybaras from the south of Brazil. Antibodies to T. gondii were assayed in the serum of capybaras using the indirect fluorescent antibody test (IFAT > or = 1:16). Blood, liver, heart, lymph nodes, and spleen tissues were collected and tested by polymerase chain reaction (PCR) for B1 gene and ITS1 region. The results showed that 61.5% (16/26) capybaras were seropositive to T. gondii. Titers of specific antibodies to T. gondii ranged from 1:16 to 1:512. Among the feral rodents studied, 7.7% (2/26) were PCR positive for B1 gene assay and 11.5% (3/26) were positive for ITS1 PCR assay; for both test, the prevalence was 15.4%. Liver, heart, and blood tissues were those which tested positive for the apicomplexan. Our findings show a high percentage of infection with T. gondii in asymptomatic capybaras. Based on those data, we hypothesize that the consumption of raw or undercooked capybara meat could be a source of infection for humans.

  18. Toxoplasma gondii Infection in Farmed Wild Boars (Sus scrofa) in Three Cities of Northeast China.

    PubMed

    Bai, Meng-Jie; Zou, Yang; Elsheikha, Hany M; Ma, Jian-Gang; Zheng, Wen-Bin; Zhao, Quan; Zhang, Xiao-Xuan; Zhu, Xing-Quan

    2017-04-07

    The apicomplexan protozoan parasite Toxoplasma gondii is a widely distributed etiological agent of foodborne illness. This parasite can cause production losses in livestock and serious disease in humans through consumption of contaminated meat. Pig meat is the most likely source of human infection, and wild boars may play a role in the transmission of T. gondii by serving as a reservoir host. This study aimed to investigate the seroprevalence of antibodies to T. gondii among farmed wild boars in China. In an 11-month survey, a total of 882 serum samples were obtained from farmed wild boars from three cities (Jilin City, Siping City, and Baishan City) in Jilin province, Northeast China and were tested for antibodies specific for T. gondii. Using modified agglutination test and a cutoff titer of 1:25, the prevalence of T. gondii infection in the examined samples was 10.0% (88 of 882). The highest seroprevalence was observed in animals from Jilin city (15.3%, 43/281) and followed by Siping (11.4%, 30/263) and Baishan (4.4%, 15/338). Logistic regression analysis revealed a significant correlation between the investigated geographic region and T. gondii infection. In addition, prevalence was higher in females compared to males, and the highest prevalence was detected in piglets. These findings indicate that farmed wild boars may become a source of foodborne toxoplasmosis, posing a food safety threat to the public health in the investigated areas. Implementation of effective measures to control T. gondii infection in farmed wild boars in China may be warranted.

  19. Clustering of Toxoplasma gondii Infections Within Families of Congenitally Infected Infants

    PubMed Central

    Contopoulos-Ioannidis, Despina; Wheeler, Kelsey M.; Ramirez, Raymund; Press, Cindy; Mui, Ernest; Zhou, Ying; Van Tubbergen, Christine; Prasad, Sheela; Maldonado, Yvonne; Withers, Shawn; Boyer, Kenneth M.; Noble, A. Gwendolyn; Rabiah, Peter; Swisher, Charles N.; Heydemann, Peter; Wroblewski, Kristen; Karrison, Theodore; Grigg, Michael E.; Montoya, Jose G.; McLeod, Rima

    2015-01-01

    Background. Family clusters and epidemics of toxoplasmosis in North, Central, and South America led us to determine whether fathers of congenitally infected infants in the National Collaborative Chicago-Based Congenital Toxoplasmosis Study (NCCCTS) have a high incidence of Toxoplasma gondii infection. Methods. We analyzed serum samples collected from NCCCTS families between 1981 and 2013. Paternal serum samples were tested for T. gondii antibodies with immunoglobulin (Ig) G dye test and IgM enzyme-linked immunosorbent assay. Additional testing of paternal serum samples was performed with differential-agglutination and IgG avidity tests when T. gondii IgG and IgM results were positive and serum samples were collected by the 1-year visit of the congenitally infected child. Prevalence of paternal seropositivity and incidence of recent infection were calculated. We analyzed whether certain demographics, maternal parasite serotype, risk factors, or maternal/infant clinical manifestations were associated with paternal T. gondii infection status. Results. Serologic testing revealed a high prevalence (29 of 81; 36%) of T. gondii infection in fathers, relative to the average seropositivity rate of 9.8% for boys and men aged 12–49 years in the United States between 1994 and 2004 (P < .001). Moreover, there was a higher-than-expected incidence of recent infections among fathers with serum samples collected by the 1-year visit of their child (6 of 45; 13%; P < .001). No demographic patterns or clinical manifestations in mothers or infants were associated with paternal infections, except for sandbox exposure. Conclusions. The high prevalence of chronic and incidence of recent T. gondii infections in fathers of congenitally infected children indicates that T. gondii infections cluster within families in North America. When a recently infected person is identified, family clustering and community risk factors should be investigated for appropriate clinical management

  20. Detection and determination of Toxoplasma gondii seroprevalence in native Korean goats (Capra hircus coreanae).

    PubMed

    Jung, Byeong Yeal; Gebeyehu, Eyerusalem Bizuneh; Lee, Seung-Hun; Seo, Min-Goo; Byun, Jae-Won; Oem, Jae Ku; Kim, Ha-Young; Kwak, Dongmi

    2014-05-01

    Toxoplasma gondii is an important zoonotic protozoan pathogen that causes serious illness in immunocompromised humans and infection in animals worldwide. The current study was conducted for detection of T. gondii infection and determination of the seroprevalence of the pathogen in native Korean goats (Capra hircus coreanae). Analysis of a total of 610 sera samples collected from 60 herds between 2009 and 2011 were performed using a commercial enzyme-linked immunosorbent assay (ELISA) kit for detection of anti-T. gondii IgG antibodies. Among the animals tested, 5.1% (31/610) showed seropositivity for anti-T. gondii antibodies, and 38.3% (23/60) of the herds were seropositive. The prevalence rates between young (<1 year) and adult (≥1 and ≤3 years) goats were 7.0% and 4.1%, respectively, without statistical significance (p>0.05). Likewise, the prevalence rates observed during cold season (October-March) and warm season (April-September) were 2.9% and 5.5%, respectively, without statistical significance. Seroprevalence rates observed in the northern, central, and southern regions were 7.9%, 3.8%, and 4.2%, respectively. In conclusion, we report for the first time on the seroprevalence of anti-T. gondii antibodies in native Korean goats (Capra hircus coreanae). The results of this study also indicate that there is a nationwide distribution of T. gondii infection among goats. Therefore, the implementation of integrated control strategies as well as measures for prevention and control of T. gondii infection within goats is recommended.

  1. Seroprevalence of Toxoplasma gondii infection in domestic sheep and goats in Borno state, Nigeria.

    PubMed

    Kamani, Joshua; Mani, Aliyu U; Egwu, Godwin O

    2010-04-01

    Serum samples were collected from 372 sheep and same number of goats from the three geopolitical zones of Borno state, Nigeria. The samples were tested for the presences of Toxoplasma gondii antibodies by enzyme-linked immunosorbent assay. Of these, 6.7% (25/372) and 4.6% (17/372) of sheep and goats, respectively, were found to be seropositive to T. gondii antibodies, both far less than the estimated global average of 31%. Results were statistically analyzed by chi-square (chi(2)) test. The results showed that age, environmental conditions, and farm location are the main determinants of prevalence of antibodies against T. gondii in the study area. Older animals (>3 years) are significantly more infected than younger animals (between 6 months and 1 year).The prevalence of anti T. gondii antibodies is significantly higher (P < 0.05) in both sheep and goats sampled from the southern zone than the northern zone. Animals from the southern zones are about four times more likely to be exposed to T. gondii infection than those in the northern zone, (sheep; odds ratio (OR) = 4.25, 95% confidence interval (CI) = 1.177-15.36, P = 0.018), (goats; OR = 4.38, 95% CI = 0.925-20.73, P = 0.04). Farm location in urban area was identified as a risk factor for sheep (OR = 6.06, 95% CI = 2.53-14.54, P = 0.000), and goats (OR = 4.99, 95% CI = 1.59-15.62, P = 0.004). Current data on prevalence of ovine and caprine T. gondii in Borno state are provided by the study as well as identifying the main risk factors associated with T. gondii infection in the area.

  2. Overlapping Toxoplasma gondii Genotypes Circulating in Domestic Animals and Humans in Southeastern Brazil

    PubMed Central

    Silva, Letícia A.; Andrade, Renata O.; Carneiro, Ana Carolina A. V.; Vitor, Ricardo W. A.

    2014-01-01

    Although several Toxoplasma gondii genotyping studies have been performed in Brazil, studies of isolates from animals in the state of Minas Gerais are rare. The objective of this study was to conduct a genotypic characterization of T. gondii isolates obtained from dogs, free-range chickens, and humans in Minas Gerais and to verify whether the T. gondii genotypes circulating in domestic animals correspond to the genotypes detected in humans. Genetic variability was assessed by restricted fragment length polymorphism at 11 loci (SAG1, 5′+3′SAG2, SAG2 alt, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico). Twelve different genotypes were identified among the 24 isolates studied, including 8 previously identified genotypes and 4 new genotypes. The genetic relationship of the 24 T. gondii isolates, together with the genotypes previously described from 24 human newborns with congenital toxoplasmosis, revealed a high degree of similarity among the genotypes circulating in humans and animals in Minas Gerais. The most common genotypes among these species were BrII, BrIII, ToxoDB #108, and ToxoDB #206. Restricted fragment length polymorphism at the CS3 locus of these 48 isolates showed that the majority of isolates presented alleles I (50%) or II (27%). Isolates harboring allele III at the CS3 locus presented low virulence for mice, whereas those harboring alleles I or II presented higher virulence. These results confirm the utility of marker CS3 for predicting the virulence of Brazilian isolates of T. gondii in mice. No association was found between the allele type and clinical manifestations of human congenital toxoplasmosis. This is the first report of T. gondii genotyping that verifies the overlapping genotypes of T. gondii from humans and animals in the same geographic region of Brazil. Our results suggest that there is a common source of infection to the species studied, most likely oocysts contaminating the environment. PMID:24587295

  3. A Systematic Meta-Analysis of Toxoplasma gondii Prevalence in Food Animals in the United States.

    PubMed

    Guo, Miao; Mishra, Abhinav; Buchanan, Robert L; Dubey, Jitender P; Hill, Dolores E; Gamble, H Ray; Jones, Jeffrey L; Pradhan, Abani K

    2016-03-01

    Toxoplasma gondii is a widely distributed protozoan parasite. The Centers for Disease Control and Prevention reported that T. gondii is one of three pathogens (along with Salmonella and Listeria), that together account for >70% of all deaths due to foodborne illness in the United States. Food animals are reservoirs for T. gondii and act as one of the sources for parasite transmission to humans. Based on limited population-based data, the Food and Agriculture Organization/World Health Organization estimated that approximately 22% of human T. gondii infections are meatborne. The objective of the current study was to conduct a systematic meta-analysis to provide a precise estimation of T. gondii infection prevalence in food animals produced in the United States. Four databases were searched to collect eligible studies. Prevalence was estimated in six animal categories (confinement-raised market pigs, confinement-raised sows, non-confinement-raised pigs, lamb, goats, and non-confinement-raised chickens) by a quality-effects model. A wide variation in prevalence was observed in each animal category. Animals raised outdoors or that have outdoor access had a higher prevalence as compared with animals raised indoors. T. gondii prevalence in non-confinement-raised pigs ranked the highest (31.0%) followed by goats (30.7%), non-confinement-raised chickens (24.1%), lambs (22.0%), confinement-raised sows (16.7%), and confinement-raised market pigs (5.6%). These results indicate that T. gondii-infected animals are a food safety concern. The computed prevalence can be used as an important input in quantitative microbial risk assessment models to further predict public health burden.

  4. Overlapping Toxoplasma gondii genotypes circulating in domestic animals and humans in Southeastern Brazil.

    PubMed

    Silva, Letícia A; Andrade, Renata O; Carneiro, Ana Carolina A V; Vitor, Ricardo W A

    2014-01-01

    Although several Toxoplasma gondii genotyping studies have been performed in Brazil, studies of isolates from animals in the state of Minas Gerais are rare. The objective of this study was to conduct a genotypic characterization of T. gondii isolates obtained from dogs, free-range chickens, and humans in Minas Gerais and to verify whether the T. gondii genotypes circulating in domestic animals correspond to the genotypes detected in humans. Genetic variability was assessed by restricted fragment length polymorphism at 11 loci (SAG1, 5'+3'SAG2, SAG2 alt, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico). Twelve different genotypes were identified among the 24 isolates studied, including 8 previously identified genotypes and 4 new genotypes. The genetic relationship of the 24 T. gondii isolates, together with the genotypes previously described from 24 human newborns with congenital toxoplasmosis, revealed a high degree of similarity among the genotypes circulating in humans and animals in Minas Gerais. The most common genotypes among these species were BrII, BrIII, ToxoDB #108, and ToxoDB #206. Restricted fragment length polymorphism at the CS3 locus of these 48 isolates showed that the majority of isolates presented alleles I (50%) or II (27%). Isolates harboring allele III at the CS3 locus presented low virulence for mice, whereas those harboring alleles I or II presented higher virulence. These results confirm the utility of marker CS3 for predicting the virulence of Brazilian isolates of T. gondii in mice. No association was found between the allele type and clinical manifestations of human congenital toxoplasmosis. This is the first report of T. gondii genotyping that verifies the overlapping genotypes of T. gondii from humans and animals in the same geographic region of Brazil. Our results suggest that there is a common source of infection to the species studied, most likely oocysts contaminating the environment.

  5. Occurrence of Neospora caninum and Toxoplasma gondii infections in ovine and caprine abortions.

    PubMed

    Moreno, B; Collantes-Fernández, E; Villa, A; Navarro, A; Regidor-Cerrillo, J; Ortega-Mora, L M

    2012-06-08

    Neospora caninum and Toxoplasma gondii are closely related cyst-forming apicomplexan parasites identified as important causes of reproductive failure in cattle and small ruminants, respectively. Protozoan abortion in small ruminants is traditionally associated with T. gondii, but the importance of N. caninum remains uncertain. The aim of this study was to investigate the presence of N. caninum and T. gondii infections in abortion cases in small ruminants submitted for diagnosis. For this purpose, 74 ovine and 26 caprine aborted foetuses were recovered from different areas in Spain. Foetal histopathology was used to detect the presence of protozoal-associated lesions in brain. The presence of N. caninum and T. gondii was confirmed by PCR. Protozoal infection was detected in 17 out of 100 (17%) foetuses examined by at least one of the diagnostic techniques used. Lesions suggestive of protozoal infection were observed in 10.8% (8/74) and 15.4% (4/26) of the ovine and caprine abortions respectively. N. caninum and T. gondii infection was detected by PCR in 6.8% (5/74) and 5.4% (4/74) of sheep foetuses, respectively, of which five showed protozoal-associated lesions. N. caninum DNA was detected in 11.5% (3/26) of goat foetuses, of which two showed protozoal-associated lesions, whereas T. gondii DNA was detected in one goat foetus with no lesions. The simultaneous presence of N. caninum and T. gondii DNA was detected in one sheep foetus with severe lesions. This study demonstrates that N. caninum plays a significant role in abortion in small ruminants in the studied population. In addition, our results highlight the importance of differentiating between protozoa whenever characteristic lesions are observed.

  6. Detection of Toxoplasma gondii in water by an immunomagnetic separation method targeting the sporocysts.

    PubMed

    Dumètre, Aurélien; Dardé, Marie-Laure

    2007-09-01

    An immunomagnetic separation (IMS) method was developed to detect Toxoplasma gondii in fresh waters by using the monoclonal antibody 4B6 targeting the sporocyst wall of T. gondii, Hammondia hammondi, Hammondia heydorni, and Neospora caninum. Water concentrates obtained by filtering 10- to 20-l samples samples were spiked with Toxoplasma oocysts, sonicated to release the sporocysts, and analyzed by IMS-4B6. Mean sporocyst recoveries were 74.5 +/- 5.3% in drinking water, 30.6 +/- 2.4 and 37.1 +/- 3.2% in surface waters, and 81.6 +/- 2.1% in IMS buffer. Then, this IMS method was integrated in a multistep procedure (i.e., filtration, IMS, immunofluorescence and autofluorescence) to detect Toxoplasma in unspiked and spiked water samples (10-30 l) of various qualities. Sporocyst recoveries ranged from 14.4 to 44.7% in drinking water samples spiked with 1-10 oocysts/l, and from 17.8 to 32.5% in surface water samples spiked with 10 oocysts/l. Sporocysts were not detected in 25 unspiked water samples. A sporocyst-like structure was seen in one of these unspiked samples, but its coccidian nature could not be proved by three polymerase chain reaction (PCR) methods targeting sequences of coccidian small and large subunit rRNA genes and Toxoplasma repetitive elements. In conclusion, IMS-4B6 is relevant for the detection of Toxoplasma in water generating small concentrates (<1 ml). Due to 4B6 cross-reactions, a PCR would be useful to further characterize coccidian sporocysts found microscopically.

  7. Seroepidemiology of infection with Toxoplasma gondii in migrant agricultural workers living in poverty in Durango, Mexico

    PubMed Central

    2013-01-01

    Background Migrant agricultural workers are a group of people living in poverty with poor housing, sanitary conditions and hygiene practices. Little is known about the epidemiology of infection with Toxoplasma gondii in migrant agricultural workers. Methods We investigated the presence of anti-Toxoplasma IgG and IgM antibodies in 173 migrant workers hired for seasonal agricultural work in Durango State in northern Mexico using enzyme-linked immunoassays. Results Of the 173 migrant workers (mean age 34.82 ± 14.01 years), 50 (28.9%) had anti-Toxoplasma IgG antibodies and 36 (20.8%) had anti-Toxoplasma IgM antibodies. Seroprevalence was not influenced by gender, age, birth place, or educational level. In contrast, seroprevalence was significantly higher in workers residing in rural areas than those in urban or suburban areas. Migrant workers suffering from memory impairment, dizziness, or syncope had significantly higher seroprevalence of anti-T. gondii IgG antibodies than those without such clinical features. Logistic regression analysis showed that T. gondii exposure was positively associated with consumption of unwashed raw vegetables (OR = 2.39; 95% CI: 1.06-5.35; P = 0.03) and low frequency of eating out of home (OR = 3.87; 95% CI: 1.43-10.42; P = 0.007), and negatively associated with national trips (OR = 0.30; 95% CI: 0.13-0.65; P = 0.003) and consumption of raw milk (OR = 0.40; 95% CI: 0.18-0.87; P = 0.02). Other behavioral characteristics including consumption of meat or untreated water were not associated with T. gondii infection. Conclusions This is the first report of T. gondii infection in internal migrant agricultural workers living in poverty. Results deserve further investigation of causal relations between clinical symptoms and infection, and may be useful for optimal planning of preventive measures. PMID:23601076

  8. MicroRNA-132 dysregulation in Toxoplasma gondii infection has implications for dopamine signaling pathway

    PubMed Central

    Xiao, Jianchun; Li, Ye; Prandovszky, Emese; Karuppagounder, Senthilkumar S.; Talbot, C. Conover; Dawson, Valina L.; Dawson, Ted M.; Yolken, Robert H.

    2014-01-01

    Congenital toxoplasmosis and toxoplasmic encephalitis can be associated with severe neuropsychiatric symptoms. However, which host cell processes are regulated and how Toxoplasma gondii affects these changes remain unclear. MicroRNAs (miRNAs) are small noncoding RNA sequences critical to neurodevelopment and adult neuronal processes by coordinating the activity of multiple genes within biological networks. We examined the expression of over 1000 miRNAs in human neuroepithelioma cells in response to infection with Toxoplasma. MiR-132, a cyclic AMP-responsive element binding (CREB)-regulated miRNA, was the only miRNA that was substantially upregulated by all three prototype Toxoplasma strains. The increased expression of miR-132 was also documented in mice following infection with Toxoplasma. To identify cellular pathways regulated by miR-132, we performed target prediction followed by pathway enrichment analysis in the transcriptome of Toxoplasma-infected mice. This led us to identify 20 genes and dopamine receptor signaling was their strongest associated pathway. We then examined myriad aspects of the dopamine pathway in the striatum of Toxoplasma infected mice 5 days after infection. Here we report decreased expression of D1-like dopamine receptors (DRD1, DRD5), metabolizing enzyme (MAOA) and intracellular proteins associated with the transduction of dopamine-mediated signaling (DARPP-32 phosphorylation at Thr34 and Ser97). Increased concentrations of dopamine and its metabolites, serotonin and 5-hydroxyindoleacetic acid were documented by HPLC analysis; however, the metabolism of dopamine was decreased and serotonin metabolism was unchanged. Our data show that miR-132 is upregulated following infection with Toxoplasma and is associated with changes in dopamine receptor signaling. Our findings provide a possible mechanism for how the parasite contributes to the neuropathology of infection. PMID:24657774

  9. Toxoplasma gondii seroprevalence in donkeys (Equus asinus) from the U.S.A. and isolation of T. gondii from cats on donkey farms

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  10. Dolphin Morbillivirus and Toxoplasma gondii coinfection in a Mediterranean fin whale (Balaenoptera physalus)

    PubMed Central

    2012-01-01

    Background Although Morbillivirus and Toxoplasma gondii have emerged as important pathogens for several cetaceans populations over the last 20 years, they have never been identified together in a Mysticete. In particular, morbilliviral infection has been never described in the Mediterranean fin whale population. Case presentation On January 2011 an adult male of fin whale (Balaenoptera physalus) stranded along the Tyrrhenian coastline of Italy. During necropsy, tissue samples from heart, skeletal muscle, mesenteric lymph nodes, liver, spleen, lung, and kidney were collected and subsequently analyzed for Morbillivirus and Toxoplasma gondii by microscopic and molecular methods. Following the detailed necropsy carried out on this whale, molecular analysis revealed, for the first time, the simultaneous presence of a Dolphin Morbillivirus (DMV) and T. gondii infection coexisting with each other, along with high organochlorine pollutant concentrations, with special reference to DDT. Conclusion This report, besides confirming the possibility for Mysticetes to be infected with DMV, highlights the risk of toxoplasmosis in sea water for mammals, already immunodepressed by concurrent factors as infections and environmental contaminants. PMID:22397492

  11. Identification and characterization of a Fc receptor activity on the Toxoplasma gondii tachyzoite.

    PubMed

    Vercammen, M; el Bouhdidi, A; Ben Messaoud, A; de Meuter, F; Bazin, H; Dubremetz, J F; Carlier, Y

    1998-01-01

    The Immunoglobulin (Ig) binding capacity of Toxoplasma gondii tachyzoites was investigated using fluorescence flow-cytometry analysis. Polyclonal mouse, human and rat immunoglobulins without specific anti-Toxoplasma activity bound to parasites in a concentration-dependent manner, saturating them at circulating serum concentrations. The immunoglobulin class and subclass specificity of binding was investigated using irrelevant monoclonal antibodies. IgM, IgA and IgG reacted with the parasite membrane. The attachment of mouse IgM to the parasite surface was hampered by mouse IgG1, IgG2a, IgG2b and IgG3. The binding of mouse IgG was proportionally reduced with increasing concentrations of mouse monoclonal IgM. The binding of murine immunoglobulin was diminished when in presence of human IgG. Purified Fc- but not Fab portions of immunoglobulins, fixed to parasites. Using labelled calibrated beads, the Ig binding capacity of parasites was estimated to be 6900 +/- 500 sites per tachyzoite. The Kd of the T. gondii Fc Receptor (FcR) activity was determined at 1.4 +/- 0.1 microM (mean +/- SEM). Such FcR activity was reduced by phospholipase C, trypsin and pronase treatment of the parasites. These data show a low affinity FcR activity on T. gondii tachyzoites which recognizes Ig of different species and isotypes and is likely supported by a glycosyl-phosphatidylinositol (GPI)-anchored surface protein of the parasite.

  12. Parasite-augmented mate choice and reduction in innate fear in rats infected by Toxoplasma gondii.

    PubMed

    Vyas, Ajai

    2013-01-01

    Typically, female rats demonstrate clear mate choice. Mate preference is driven by the evolutionary need to choose males with heritable parasite resistance and to prevent the transmission of contagious diseases during mating. Thus, females detect and avoid parasitized males. Over evolutionary time scales, parasite-free males plausibly evolve to advertise their status. This arrangement between males and females is obviously detrimental to parasites, especially for sexually transmitted parasites. Yet Toxoplasma gondii, a sexually transmitted parasite, gets around this obstacle by manipulating mate choice of uninfected females. Males infected with this parasite become more attractive to uninfected females. The ability of T. gondii to not only advantageously alter the behavior and physiology of its host but also secondarily alter the behavior of uninfected females presents a striking example of the 'extended phenotype' of parasites. Toxoplasma gondii also abolishes the innate fear response of rats to cat odor; this likely increases parasite transmission through the trophic route. It is plausible that these two manipulations are not two distinct phenotypes, but are rather part of a single pattern built around testosterone-mediated interplay between mate choice, parasitism and predation.

  13. SURVEY OF TOXOPLASMA GONDII ANTIBODIES IN MAGELLANIC PENGUINS (SPHENISCUS MAGELLANICUS FORSTER, 1781).

    PubMed

    Gennari, Solange M; Niemeyer, Cláudia; Catão-Dias, José L; Soares, Herbert S; Acosta, Igor C L; Dias, Ricardo A; Ribeiro, Jéssica D; Lassalvia, Cristiane; Maracini, Pryscilla; Kolesnikovas, Cristiane K M; Mayorga, Luis F S P; Dubey, Jitender P

    2016-03-01

    Magellanic penguins (Spheniscus magellanicus) breed on the Atlantic and Pacific coasts of the southernmost parts of South America and migrate northward as far as Peru and Brazil. Serum samples (n = 100) from Magellanic penguins from three zoos and two rehabilitation centers (RCs) in Brazil were assayed for the presence of antibodies to Toxoplasma gondii by means of the modified agglutination test (MAT, cut-off ≥ 20). The penguins were categorized as young (≤4 yr old) or adults (≥4 yr old) and sexed (male, female, or not identified), and data were analyzed using the chi-square test (P ≤ 0.05). Toxoplasma gondii antibodies were found in 28% of penguins: 25.8% males, 27.8% females, 30.3% unknown sex, 25.4% young, and 31.1% adults. Statistical analyses did not find any difference (P > 0.05) with respect to age, sex, or source of birds. This is the first report of T. gondii antibodies in S. magellanicus.

  14. Prevalence of Toxoplasma gondii infection in Myocastor coypus in a protected Italian wetland

    PubMed Central

    2011-01-01

    Background Toxoplasma gondii is the causative agent for a major zoonosis with cosmopolitan distribution. Water has been implicated in outbreaks of toxoplasmosis in recent years. Coypus (Myocastor coypus), commonly nutria, are large semi-aquatic invasive rodents, naturalized throughout European countries, including most wetlands of Central Italy. The habitat of these animals is both terrestrial and aquatic, making them a species highly exposed to the parasite. Findings The occurrence of the infection was evaluated using a modified agglutination test (MAT) in 74 adult coypus from a naturalized population living in a wetland of Central Italy. Nested PCR (n-PCR) assay was carried out on some of them. Positive T. gondii MAT results were found in 44 animals (59·4%), 30 males (68·2%) and 14 females (31·8%). Antibody titers were ranging from 20 to 40960, while 12 out of 23 (52·2%), examined animals, 8 males (66·7%) and 4 females (33·3%), resulted positive to n-PCR. All n-PCR positive animals were seropositive, showing antibody titers ranging from 640 to 40960. Conclusions Our results indicate that examined animals are heavily parasitized with Toxoplasma. This suggests that coypus could be a reservoir of this parasite, because they can be eaten both by scavenger animals and by humans, and that these animals would play a role in maintaining the cycle of T. gondii. PMID:22196032

  15. Frequency of Toxoplasma gondii in pork meat in Ocotlán, Jalisco, Mexico.

    PubMed

    Galván-Ramirez, M L; Madriz Elisondo, A L; Rico Torres, C P; Luna-Pastén, H; Rodríguez Pérez, L R; Rincón-Sánchez, A R; Franco, R; Salazar-Montes, A; Correa, D

    2010-06-01

    Toxoplasmosis is an infection caused by Toxoplasma gondii, an intracellular obligate parasite. Its transmission has usually been attributed to ingestion of undercooked or raw meat. The frequency of T. gondii in pork, the most common meat for human consumption in Jalisco, Mexico, is unknown; in Guadalajara city high prevalence of human toxoplasmosis has been documented. Forty-eight samples of pork meat from butcher shops in Ocotlán city were analyzed. Through bioassay, 50 g of tissue was homogenized in an acidic pepsin solution and inoculated subcutaneously to previously immunosuppressed mice. Blood samples from the mice tail vein were obtained before inoculation and 7, 14, 28, and 45 days postinoculation to analyze anti-Toxoplasma immunoglobulin (Ig) M and IgG antibody kinetics by indirect enzyme-linked immunosorbent assay. For histopathology, small fragments of the brain, lungs, heart, and skeletal muscle were extracted on day 45 and were stained with hematoxylin and eosin. Also, DNA was extracted from the pork meat for PCR amplification of the B1 gene. Even though all pork samples were negative by histopathology and PCR, IgG and IgM antibodies against T. gondii were detected in 1 of the 48 inoculated mice, reflecting a frequency of 2.1% positive pork meat, which is lower than expected but similar to that found in other regions.

  16. A preliminary study on the quality and safety of milk in donkeys positive for Toxoplasma gondii.

    PubMed

    Martini, M; Altomonte, I; Mancianti, F; Nardoni, S; Mugnaini, L; Salari, F

    2014-12-01

    Toxoplasmosis is one of the five parasitic diseases considered as a priority for public health action. The consumption of raw milk products represents a possible risk, in particular for certain categories of people. The aim of this study was to evaluate the possible effects of Toxoplasma gondii on milk yield and quality in sero-positive animals with parasitemia. Eighteen healthy lactating Amiata jennies, between 90 and 180 days were included in the study. Four donkeys scored positive for immunofluorescent antibody test (IFAT), and each IFAT positive donkey presented parasitic DNA both in the blood and milk. No significant differences were found between milk yield in PCR-positive donkeys compared with the negative cases, however the former tended to have a greater production. Milk quality in the positive donkeys showed a significantly lower percentage of casein (0.72% v. 0.81%) and ash (0.32% v. 0.37%). Positive cases had a highly significant larger average diameter of globules (2.35 µm) and fewer globules/ml (2.39 × 10(8)). Somatic cell and bacterial counts were normal and in agreement with the literature. Toxoplasma gondii did not seem to present clinical forms in lactating jennies. Further in vivo studies are needed to further assess the risk of T. gondii transmission through donkey milk, together with the impact of different stages of infection on milk quality.

  17. The Effect of Latent Toxoplasma gondii Infection on the Immune Response in HIV-Infected Patients.

    PubMed

    Beran, Ondrej; Kodym, Petr; Maly, Marek; Davidova, Alzbeta; Reinvartova, Gabriela; Jilich, David; Holub, Michal; Rozsypal, Hanus

    2015-01-01

    A relationship between latent toxoplasmosis and the immune system during HIV disease is poorly understood. Therefore, the aim of this follow-up study was to characterize immunological parameters in HIV-infected patients with latent toxoplasmosis and noninfected individuals. A total of 101 HIV-infected patients were enrolled in the study. The patients were classified into two groups based on anti-Toxoplasma gondii antibodies: a group of 55 toxoplasma-positive persons (TP) and a group of 46 toxoplasma-negative persons (TN). Absolute counts of several lymphocyte subsets decreased in the TP group, namely, T cells (p = 0.007), B cells (p = 0.002), NK cells (p = 0.009), CD4 T cells (p = 0.028), and CD8 T cells (p = 0.004). On the other hand, the percentage of CD8 T cells expressing CD38 and HLA-DR significantly increased during the follow-up in the TP group (p = 0.003, p = 0.042, resp.) as well as the intensity of CD38 and HLA-DR expression (MFI) on CD8 T cells (p = 0.001, p = 0.057, resp.). In the TN group, analysis of the kinetics of immunological parameters revealed no significant changes over time. In conclusion, the results suggest that latent T. gondii infection modulates the immune response during HIV infection.

  18. Toxoplasma gondii, Neospora caninum, Sarcocystis neurona, and Sarcocystis canis-like infections in marine mammals

    USGS Publications Warehouse

    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).

  19. Toxoplasma gondii, Neospora caninum, Sarcocystis neurona, and Sarcocystis canis-like infections in marine mammals.

    PubMed

    Dubey, J P; Zarnke, R; Thomas, N J; Wong, S K; Van Bonn, W; Briggs, M; Davis, J W; Ewing, R; Mense, M; Kwok, O C H; Romand, S; Thulliez, P

    2003-10-30

    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 > or =1:25) 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 (Eumetopias jubatus) [corrected] 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).

  20. Seroprevalence of Toxoplasma gondii and Neospora caninum in dogs from Korea.

    PubMed

    Nguyen, Thuy Thi-Dieu; Choe, Se-Eun; Byun, Jae-Won; Koh, Hong-Bum; Lee, Hee-Soo; Kang, Seung-Won

    2012-03-01

    Toxoplasma gondii and Neospora caninum are closely related protozoan parasites, they share many common hosts, and can cause neurological diseases in dogs. Dogs can have close contacts with humans and livestock and therefore they can act as reservoirs of these parasites. The aim of this study was to survey the seroprevalence of antibodies against T. gondii and N. caninum and their co-infection rate in dogs in Korea. In total, sera from 553 domestic dogs were collected from different breeds, sexes, and ages of dogs from nine provinces across the country of Korea during 2006 and 2007. The presence of antibodies against T. gondii and N. caninum was analyzed using the latex agglutination test (LAT) with a cut-off value of 1:32, and the indirect fluorescent antibody test (IFAT) using a serum titer of 1:100. In the total dog population, 71 (12.8%) dogs were positive for anti-T. gondii antibodies and only 20 (3.6%) were positive for anti-N. caninum antibodies. Relatively higher seropositive frequencies of antibodies against T. gondii (20.1%) and N. caninum (4.9%) were detected in the dog population from the Gyeonggi. A higher proportion of animals seropositive for anti-T. gondii antibodies was found in stray dog populations as compared to household dog populations: 18.5% (59/319) vs 5.1% (12/234), respectively. The Chi-square tests revealed significant differences in the seropositive frequencies of antibodies against T. gondii between stray and household dogs in the total population (p<0.0001), and in dogs from the Gyeonggi (p<0.01). No significant differences were observed for the presence of antibodies against T. gondii or N. caninum when compared across the sex or age (p>0.05). The first serological survey on antibodies against both T. gondii and N. caninum parasites across the entire country showed that co-infection was not common in these canine populations with a seropositive level of 0.72%. The significantly higher positive frequency of T. gondii antibodies in stray