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. Copyright © 2016 Elsevier Inc. All rights reserved.

One-pot, multicomponent synthesis of 2,3-disubstituted quinazolin-ones with potent and selective activity against Toxoplasma gondii.

PubMed

Brown, Carla E; Kong, Tiffany; Bordón, Claudia; Yolken, Robert; Jones-Brando, Lorraine; McNulty, James

2018-05-15

The discovery of two quinazolinones with selective, single-digit micromolar activity (IC 50  = 6-7 µM) against the tachyzoites of the apicomplexan parasite Toxoplasma gondii is reported. These potent and selective third generation derivatives contain a benzyloxybenzyl substituent at C2 and a bulky aliphatic moiety at N3. Here we show that these quinazolinones inhibit T. gondii tachyzoite replication in an established infection, but do not significantly affect host cell invasion by the tachyzoites. Copyright © 2018 Elsevier Ltd. All rights reserved.

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

CD11c- and CD11b-expressing mouse leukocytes transport single Toxoplasma gondii tachyzoites to the brain

PubMed Central

Courret, Nathalie; Darche, Sylvie; Sonigo, Pierre; Milon, Geneviève; Buzoni-Gâtel, Dominique; Tardieux, Isabelle

2006-01-01

The protozoan parasite Toxoplasma gondii enters hosts through the intestinal mucosa and colonizes distant tissues such as the brain, where its progeny persists for a lifetime. We investigated the role of CD11c- and CD11b-expressing leukocytes in T gondii transport during the early step of parasitism from the mouse small intestine and during subsequent parasite localization in the brain. Following intragastric inoculation of cyst-containing parasites in mice, CD11c+ dendritic cells from the intestinal lamina propria, the Peyer patches, and the mesenteric lymph nodes were parasitized while in the blood, parasites were associated with the CD11c- CD11b+ monocytes. Using adoptive transfer experiments, we demonstrated that these parasitized cells triggered a parasitic process in the brain of naive recipient mice. Ex vivo analysis of parasitized leukocytes showed that single tachyzoites remained at the cell periphery, often surrounded by the host cell plasma membrane, but did not divide. Using either a dye that labels circulating leukocytes or an antibody known to prevent CD11b+ circulating leukocytes from leaving the microvascular bed lumen, and chimeric mice in which the hematopoietic cells expressed the green fluorescent protein, we established that T gondii zoites hijacked CD11b+ leukocytes to reach the brain extravascular space. PMID:16051744

[Protein interaction site of Toxoplasma gondii microneme protein 6 and aldolase determined by site-directed mutagenesis].

PubMed

Zheng, Bin; Yin, Zhi-Kui; Zhan, Xi-Mei

2014-06-01

To identify the protein interaction site of Toxoplasma gondii microneme protein 6 (MIC6) and aldolase by using site-directed mutagenesis. Based on Toxoplasma gondii MIC6 gene sequence (GenBank Accession No. AF110270), the specific primers were designed. Tryptophan (W)-348 of MIC6 C terminus (MIC6C) was mutated to valine (V) via site-directed mutagenesis. MIC6C W/V gene was obtained from cDNA library by PCR amplification and subcloned into pGEX-4T-1. The mutant protein GST-MIC6C W/V was expressed in E. coli, induced by 0.8 mmol/L IPTG, and purified by affinity chromatography. Glutathione sepharose beads were incubated with GST-MIC6C W/V and GST-MIC6C, respectively, and then incubated with T. gondii tachyzoites lysate, and bound proteins were eluted using sample buffer. Bound products were resolved by SDS-PAGE and Western blotting. Glutathione sepharose beads were incubated with GST-MIC6C W/V and GST-MIC6C, respectively, and then incubated with aldolase-His6. After incubation, the resin was washed and subjected to SDS-PAGE. The MIC6C W/N gene was obtained, and the recombinant plasmid MIC6C W/V/pGEX-4T-1 was successfully constructed. The mutant protein GST-MIC6C W/V was expressed and purified in vitro. SDS-PAGE analysis indicated that GST-MIC6C was co-precipitated with aldolase from T. gondii tachyzoites lysate or aldolase-His6, whereas GST-MIC6C W/V failed to precipitate aldolase from T. gondii tachyzoites lysate or aldolase-His6. Western blotting analysis using anti-aldolase antibody indicated that GST-MIC6C could pull-down aldolase from T. gondii tachyzoites lysate. Tryptophan (W348) was the interaction site of MIC6 and aldolase in T. gondii.

Prevalence of Neospora caninum and Toxoplasma gondii antibodies in sera from camels (Camelus dromedarius) in Riyadh Province, Saudi Arabia.

PubMed

Al-Anazi, Abdullah D

2011-08-01

From April to December 2010, blood samples were collected from 412 healthy camels in Riyadh province, Saudi Arabia and used to evaluate serological screening for Neospora caninum and Toxoplasma gondii infection by an indirect fluorescent antibody test (IFAT). Of the 412 camels, antibodies to N. caninum were found in sixteen in titers of 1:20 and in seven in titers of 1:40 using whole N. caninum tachyzoites as IFAT slide (VMRD Inc., Pullman, WA 99163, USA). Antibodies to T. gondii were found in nineteen camels in titers 1:20 and in eight camels in titers 1:40 using whole T. gondii tachyzoites as IFAT slide.

Clinical Toxoplasma gondii, Hammondia heydorni, and Sarcocystis spp. infections in dogs.

PubMed

Dubey, J P; Ross, A D; Fritz, D

2003-12-01

Concurrent infections with coccidians Toxoplasma gondii, Sarcocystis spp., and a Hammondia heydorni-like parasite were identified in tissues of three littermate pups on a Kelpie dog breeding farm in Australia. In total, 20 pups in four litters had died following vaccination with an attenuated distemper virus vaccine. Toxoplasma gondii tachyzoites were identified immunohistochemically in tissues of two dogs. Sarcocystis sp. sporocysts were seen in the intestinal lamina propria of two dogs. Asexual and sexual stages of H. heydorni-like parasite were found in enterocytes of the small intestine of two dogs. Ultrastructural development of schizonts and gamonts of this parasite is described. None of the protozoa in these dogs reacted with antibodies to Neospora caninum. Feeding of uncooked tissue of sheep was considered to be the likely source of infection for these coccidians in dogs.

The Effect of Vitamin D3 Alone and Mixed With IFN-γ on Tachyzoites of Toxoplasma gondii (RH Strain) Proliferation and Nitric Oxide (NO) Production in Infected Macrophages of BALB/C Mice.

PubMed

Ghaffarifar, F; Abdolah Pour, M; Sharifi, Z; Dalimi Asl, A; Al-Kawaz, E

2010-09-01

Toxoplasma gondii is an obligatory interacelullar parasite that infects nucleated cells in its intermediate hosts. The aim of the present study was to determine the effect of vitamin D3 on the multiplication of T. gondii in peritoneal macrophage of Balb/c mice and nitric oxide production by macrophages. According to usage of vitamin D3 (one dose or seven doses) and INFγ in vitro and in vivo, this study was divided into four experiments. In all experiments, the macrophages were collected from peritoneum and cultured in RPMI-1640. Then the supernatants were collected after 24 h and their nitric oxide was measure. After 96 h, the macrophages were collected and stained and the number of tachyzoites was measured. The first experiment (the mice were infected with tachyzoites and after 2 h, got one dose vitamin D3 intraperitonealy) showed the best results. The mean of tachyzoites per macrophages was 2.37, and mean±SD of nitric oxide was 187.8±9. High-level production of nitric oxide may be related to the only one injection of vitamin D3. The injection in long time might suppress the immune system.

The Hsp90 co-chaperone p23 of Toxoplasma gondii: Identification, functional analysis and dynamic interactome determination

PubMed Central

Echeverria, Pablo C.; Figueras, Maria J.; Vogler, Malvina; Kriehuber, Thomas; de Miguel, Natalia; Deng, Bin; Dalmasso, Maria C.; Matthews, Dwight E.; Matrajt, Mariana; Haslbeck, Martin; Buchner, Johannes; Angel, Sergio O.

2010-01-01

Toxoplasma gondii is among the most successful parasites, with nearly half of the human population chronically infected. Recently a link between the T. gondii Hsp90 chaperone machinery and parasite development was observed. Here, the T. gondii Hsp90 co-chaperones p23 and Hip were identified mining the Toxoplasma- database (www.toxodb.org). Their identity was confirmed by domain structure and blast analysis. Additionally, analysis of the secondary structure and studies on the chaperone function of the purified protein verified the p23 identity. Studies of co-immunoprecipitation (co-IP) identified two different types of complexes, one comprising at least Hip-Hsp70-Hsp90 and another containing at least p23-Hsp90. Indirect immunofluorescence assays showed that Hip is localized in the cytoplasm in tachyzoites and as well in bradyzoites. For p23 in contrast, a solely cytoplasmic localization was only observed in the tachyzoite stage whereas nuclear and cytosolic distribution and colocalization with Hsp90 was observed in bradyzoites. These results indicate that the T. gondii Hsp90-heterocomplex cycle is similar to the one proposed for higher eukaryotes, further highlighting the implication of the Hsp90/p23 in parasite development. Furthermore, co-IP experiments of tachyzoite/bradyzoite lysates with anti-p23 antiserum and identification of the complexed proteins together with the use of the curated interaction data available from different source (orthologs and Plasmodium databases) allowed us to construct an interaction network (interactome) covering the dynamics of the Hsp90 chaperone machinery. PMID:20403389

In vitro effects of four macrolides (roxithromycin, spiramycin, azithromycin (CP-62,993), and A-56268) on Toxoplasma gondii

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chang, H.R.; Pechere, J.C.

1988-04-01

The effect of four macrolides against intracellular Toxoplasma gondii was determined in three different in vitro systems. Unactivated murine peritoneal macrophages were infected with the virulent RH strain of T. gondii. The activity of the macrolides was first measured with (/sup 3/H)uracil, which is incorporated by the parasite but not the host cell. The 50% inhibitory concentrations (IC50s) and 95% confidence limits were calculated at 54 (38 to 73), 140 (98 to 201), 147 (101 to 214), and 246 (187 to 325) micron for roxithromycin, azithromycin (CP-62,993), A-56268, and spiramycin, respectively. Inhibition of Toxoplasma growth was confirmed by microscopic examinationmore » of the infected macrophages after treatment with roxithromycin. Compared with untreated controls, roxithromycin concentrations near the IC50s decreased the number of infected cells, the number of tachyzoites per vacuole, and the number of cells containing rosettes (i.e., clusters of more than eight tachyzoites). After treatment with the four macrolides, tachyzoites were released from the macrophages and subcultured in HeLa cells, which are nonprofessional phagocytes, to assess the viability of the remaining parasites. This showed that the macrolides at concentrations corresponding to four times their 90% inhibitory concentrations (IC90s) had no significant killing effect. At 8 times the IC90, roxithromycin showed an incomplete killing effect, similar to that of the combination of pyrimethamine (0.41 microM)-sulfadiazine (99.42 microM). All macrolides tested showed inhibitory effects against intracellular T. gondii, but amounts of azithromycin and A-56268 corresponding to the IC90 appeared to be toxic against the host macrophages, which might have had nonspecific activity against Toxoplasma metabolism.« less

Fatal Disseminated Toxoplasma gondii Infection in a Captive Harbour Porpoise (Phocoena phocoena).

PubMed

Herder, V; van de Velde, N; Højer Kristensen, J; van Elk, C; Peters, M; Kilwinski, J; Schares, G; Siebert, U; Wohlsein, P

2015-11-01

A 7-year-old female harbour porpoise (Phocoena phocoena), born and held in captivity, suffered from reduced consciousness, imprecise and circling swimming movements and long phases of immobility over a period of 3 weeks. The animal died during treatment in a Danish open sea facility. Pathological examination revealed multifocal pyogranulomatous to necrotizing meningoencephalomyelitis, ganglioneuritis, plexus chorioiditis, myocarditis, hepatitis and adrenalitis with few intralesional protozoal tachyzoites and bradyzoites within cysts. Immunohistochemistry was positive for Toxoplasma gondii antigen within the lesions. Using polymerase chain reaction (PCR), the presence of T. gondii-specific genome fragments was confirmed. A multilocus PCR-restriction fragment length polymorphism analysis using nine unlinked marker regions (nSAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1 and Apico) resulted in the identification of T. gondii type II (variant Apico Type I), which is the T. gondii genotype dominating in Germany. This is the first description of disseminated fatal toxoplasmosis in a captive harbour porpoise that lived in an open sea basin. Surface water contaminated with toxoplasma oocysts is regarded as the most likely source of infection. Copyright © 2015 Elsevier Ltd. All rights reserved.

Evidence for glycosyl-phosphatidylinositol anchoring of Toxoplasma gondii major surface antigens

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tomavo, S.; Schwarz, R.T.; Dubremetz, J.F.

1989-10-01

The four major surface antigens of Toxoplasma gondii tachyzoites (P43, P35, P30, and P22) were made water soluble by phosphatidylinositol-specific phospholipase C (PI-PLC). These antigens were biosynthetically labeled with {sup 3}H-fatty acids, ({sup 3}H)ethanolamine, and ({sup 3}H)carbohydrates. Treatment of {sup 3}H-fatty-acid-labeled parasite lysates with PI-PLC removed the radioactive label from these antigens. A cross-reacting determinant was exposed on these antigens after PI-PLC treatment.

Infection by Toxoplasma gondii Specifically Induces Host c-Myc and the Genes This Pivotal Transcription Factor Regulates

PubMed Central

Franco, Magdalena; Shastri, Anjali J.

2014-01-01

Toxoplasma gondii infection has previously been described to cause dramatic changes in the host transcriptome by manipulating key regulators, including STATs, NF-κB, and microRNAs. Here, we report that Toxoplasma tachyzoites also mediate rapid and sustained induction of another pivotal regulator of host cell transcription, c-Myc. This induction is seen in cells infected with all three canonical types of Toxoplasma but not the closely related apicomplexan parasite Neospora caninum. Coinfection of cells with both Toxoplasma and Neospora still results in an increase in the level of host c-Myc, showing that c-Myc is actively upregulated by Toxoplasma infection (rather than repressed by Neospora). We further demonstrate that this upregulation may be mediated through c-Jun N-terminal protein kinase (JNK) and is unlikely to be a nonspecific host response, as heat-killed Toxoplasma parasites do not induce this increase and neither do nonviable parasites inside the host cell. Finally, we show that the induced c-Myc is active and that transcripts dependent on its function are upregulated, as predicted. Hence, c-Myc represents an additional way in which Toxoplasma tachyzoites have evolved to specifically alter host cell functions during intracellular growth. PMID:24532536

A new set of primers for the detection of Toxoplasma gondii in amniotic fluid using polymerase chain reaction.

PubMed

Pelloux, H; Weiss, J; Simon, J; Muet, F; Fricker-Hidalgo, H; Goullier-Fleuret, A; Ambroise-Thomas, P

1996-04-15

A new PCR system including a pair of primers, a probe and an internal control were designed from the B1 gene of Toxoplasma gondii. The system described allowed the detection of less than 10 tachyzoites of the RH strain of T. gondii. Among 21 amniotic fluid samples, this system diagnosed the cases of congenital toxoplasmosis which were simultaneously diagnosed using mice inoculation, in vitro culture, and serology from both amniotic fluid and fetal blood. These results show that these new primers allow for a highly sensitive detection of T. gondii DNA.

Porcine abortion outbreak associated with Toxoplasma gondii in Jeju Island, Korea.

PubMed

Kim, Jae Hoon; Kang, Kyung Il; Kang, Wan Cheul; Sohn, Hyun Joo; Jean, Young Hwa; Park, Bong Kyun; Kim, Yongbaek; Kim, Dae Yong

2009-06-01

This report deals with the acute onset of an abortion outbreak and high sow mortality in one pig herd consisted of 1,200 pigs and 120 sows on Jeju Island, Korea. Affected pregnant sows showed clinical signs, including high fever, gradual anorexia, vomiting, depression, recumbency, prostration, abortion, and a few deaths. Four dead sows, five aborted fetuses from the same litter, and 17 sera collected from sows infected or normal were submitted to the Pathology Division of the National Veterinary Research and Quarantine Service for diagnostic investigation. Grossly, hepatomegaly and splenomegaly were observed in sows. Multiple necrotic foci were scattered in the lungs, liver, spleen, and lymph nodes. Microscopically, multifocal necrotizing lesions and protozoan tachyzoites were present in the lesions. Tachyzoites of Toxoplasma (T.) gondii were detected immunohistochemically. Latex agglutination showed that the sera of 7 of 17 (41.2%) sows were positive for antibody to T. gondii. The disease outbreak in this herd was diagnosed as epizootic toxoplasmosis. To our knowledge, this is the first report of porcine toxoplasmosis with a high abortion rate and sow mortality in Korea.

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

Semen variables of sheep (Ovis aries) experimentally infected with Toxoplasma gondii.

PubMed

Lopes, W D Z; Costa, A J; Souza, F A; Rodrigues, J D F; Costa, G H N; Soares, V E; Silva, G S

2009-04-01

The influence of Toxoplasma gondii on semen variables and sperm morphology of sheep was evaluated in eight reproductive males distributed into three experimental groups: GI, three sheep inoculated with 2.0x10(5) of P strain oocytes; GII, three sheep infected with 1.0x10(6) of RH strain tachyzoites and; GIII two control sheep. Clinical (rectal temperature, cardiac and respiratory frequencies), parasite and serology exams (IIF) were realized. Sperm variables (volume, motility, vigor and concentration) and semen morphology for each sheep were also evaluated. Thus, semen and blood collections were assessed on post-inoculation days (PIDs)-1,3,5,7,11,14 and weekly thereafter up to PID 70. Clinical alterations were observed (hypothermia and anorexia) in infected sheep from groups GI and GII. Parasitic outbreaks were detected in five sheep. All the infected sheep produced antibodies against T. gondii from PID 5 onwards, reaching a peak of 4096 and 8192 for group GI and GII sheep, respectively. Differences (P<0.05) were observed regarding the ejaculate volume between the inoculated groups (oocytes and tachyzoites) and control. Even though experimental toxoplasmic infection resulted in clinical symptomology in the inoculated sheep, the minimal alterations in sperm pathologies could not be directly attributed to T. gondii.

Molecular cloning, organellar targeting and developmental expression of mitochondrial chaperone HSP60 in Toxoplasma gondii.

PubMed

Toursel, C; Dzierszinski, F; Bernigaud, A; Mortuaire, M; Tomavo, S

2000-12-01

The obligate intracellular protozoan parasite Toxoplasma gondii has a single tubular mitochondrion. During infection, it recruits the host cell's mitochondria abutting to the intracellular vacuole, that contains the parasites. The respective contribution of host and parasitic mitochondria in the intracellular growth of T. gondii remains unknown. Heat shock protein, HSP60 has been reported in all eukaryotes examined, as an essential chaperone required for the folding and multimeric complex assembly of mitochondrial proteins. Here, we report the isolation and molecular characterization of two cDNAs corresponding to a single T. gondii gene coding for HSP60. Using a model fusion protein, preHSP60-chloramphenicol acetyl transferase (CAT), we demonstrate that the classical 22 amino acid mitochondrial presequence and the adjacent 32 amino acids of the mature protein are both required for the in vivo import into T. gondii mitochondria. The T. gondii HSP60 gene composed of five introns and six exons is transcribed into two related but differently spliced transcripts. Whereas the two transcripts can be detected in both developmental stages within the intermediate host, their levels are significantly increased in bradyzoites when compared to tachyzoites. By immunoblot analysis, the predicted 60-kDa protien corresponding to HSP60 was detected in both tachyzoite and bradyzoite forms. Using immunofluorescence assays. the polyclonal antibodies specific to T. gondii HSP60 recognized the mitochondrion in tachyzoites, as expected. In contrast, these antibodies reacted against two unknown vesicular bodies which are distinct from the classical mitochondrial pattern in bradyzoites. Taken together. these expression patterns of mitochondrial chaperone HSP60 suggests stage-specific induction of the respiratory pathway in the protozoan parasite T. gondii.

AMA1-Deficient Toxoplasma gondii Parasites Transiently Colonize Mice and Trigger an Innate Immune Response That Leads to Long-Lasting Protective Immunity

PubMed Central

Lagal, Vanessa; Dinis, Márcia; Cannella, Dominique; Bargieri, Daniel; Gonzalez, Virginie; Andenmatten, Nicole; Meissner, Markus

2015-01-01

The apical membrane antigen 1 (AMA1) protein was believed to be essential for the perpetuation of two Apicomplexa parasite genera, Plasmodium and Toxoplasma, until we genetically engineered viable parasites lacking AMA1. The reduction in invasiveness of the Toxoplasma gondii RH-AMA1 knockout (RH-AMA1KO) tachyzoite population, in vitro, raised key questions about the outcome associated with these tachyzoites once inoculated in the peritoneal cavity of mice. In this study, we used AMNIS technology to simultaneously quantify and image the parasitic process driven by AMA1KO tachyzoites. We report their ability to colonize and multiply in mesothelial cells and in both resident and recruited leukocytes. While the RH-AMA1KO population amplification is rapidly lethal in immunocompromised mice, it is controlled in immunocompetent hosts, where immune cells in combination sense parasites and secrete proinflammatory cytokines. This innate response further leads to a long-lasting status immunoprotective against a secondary challenge by high inocula of the homologous type I or a distinct type II T. gondii genotypes. While AMA1 is definitively not an essential protein for tachyzoite entry and multiplication in host cells, it clearly assists the expansion of parasite population in vivo. PMID:25847964

In Vitro Effects of Novel Ruthenium Complexes in Neospora caninum and Toxoplasma gondii Tachyzoites

PubMed Central

Barna, Fabienne; Debache, Karim; Küster, Tatiana

2013-01-01

Upon the screening of 16 antiproliferative compounds against Toxoplasma gondii and Neospora caninum, two hydrolytically stable ruthenium complexes (compounds 16 and 18) exhibited 50% inhibitory concentrations of 18.7 and 41.1 nM (T. gondii) and 6.7 and 11.3 nM (N. caninum). To achieve parasiticidal activity with compound 16, long-term treatment (22 to 27 days at 80 to 160 nM) was required. Transmission electron microscopy demonstrated the rapid impact on and ultrastructural alterations in both parasites. These preliminary findings suggest that the potential of ruthenium-based compounds should thus be further exploited. PMID:23979747

Toxoplasma gondii

USDA-ARS?s Scientific Manuscript database

Toxoplasma gondii is perhaps the most widespread protozoan parasite affecting humans with an estimated 1-2 billion of the world’s population currently infected. T. gondii, which is the only species of this genus, also infects virtually all warm blooded animals including humans, livestock, birds, an...

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

USDA-ARS?s Scientific Manuscript database

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...

Detection of Toxolasma gondii in captive wild felids.

PubMed

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

2006-01-01

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

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. Published by Elsevier B.V.

A new atypical genotype mouse virulent strain of Toxoplasma gondii isolated from the heart of a wild caught puma (Felis concolor) from Durango, Mexico.

PubMed

Dubey, J P; Alvarado-Esquivel, C; Herrera-Valenzuela, V H; Ortiz-Diaz, J J; Oliveira, S; Verma, S K; Choudhary, S; Kwok, O C H; Su, C

2013-11-08

Nothing is known of the genetic diversity of Toxoplasma gondii circulating in wildlife in Mexico. In the present study, a mouse virulent T. gondii strain was isolated from the heart of a wild puma (Felis concolor). The puma was found roaming in outskirt of Durango City, Mexico and tranquilized for moving to a zoo. The puma died during translocation and a necropsy examination was performed. The puma had an antibody titer for T. gondii of 200 by the modified agglutination test. Its heart and brain tissue were bioassayed into 2 outbred Swiss Webster (SW) and 1 gamma interferon gene knockout (KO) mouse. The KO mouse and the 2 SW mice that became infected after inoculation with homogenate of puma heart died of acute toxoplasmosis 12, 19 and 20 days p.i. respectively and tachyzoites were found in lungs of all 3 mice. None of the 4 SW and 1 KO mouse inoculated with digest of the puma brain became infected with T. gondii. Tachyzoites from the lungs of mice were propagated in cell cultures. Tachyzoites from cell culture were inoculated into 5 SW; the mice died or had to be killed 14 days p.i. and a cat fed tissues of these mice shed T. gondii oocysts. Results of mortality and infectivity of tachyzoites and oocysts in SW mice indicated that the puma T. gondii strain (designated TgPumaMe1) was virulent for outbred mice. DNA isolated from culture-derived tachyzoites was characterized using 11 PCR-RFLP markers (SAG1, 5'- and 3'-SAG2, alt.SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1 and Apico) revealed a new genotype (ToxoDB PCR-RFLP #222). Isolation of atypical genotype T. gondii from wild puma indicates that mouse virulent strains are circulating in wildlife in Mexico. Published by Elsevier B.V.

Role of NETs in the difference in host susceptibility to Toxoplasma gondii between sheep and cattle.

PubMed

Yildiz, Kader; Gokpinar, Sami; Gazyagci, Aycan Nuriye; Babur, Cahit; Sursal, Neslihan; Azkur, Ahmet Kursat

2017-07-01

The main aim of this study was to compare extracellular traps (NETs) formation by polymorphonuclear neutrophils (PMNs) of cattle and sheep when exposed to T. gondii tachyzoites in vitro. The effects of parasite concentrations and different incubation periods on NETs development in cattle and sheep PMNs were studied. The effect of NET structures on host cell invasion by tachyzoites was also studied. This is the first report of NETs development by sheep and cattle PMNs against T. gondii in vitro. T. gondii-induced extracellular DNA production from PMNs was dependent on tachyzoite concentrations and incubation time in both sheep and cattle. Many nuclear and cytoplasmic changes were observed in sheep and cattle PMNs after exposure to T. gondii tachyzoites. The typical appearance of NETs, with MPO, NE and histone (H3) attached to extracellular DNA, was observed. Tachyzoites were entrapped within this structure. Myeloperoxidase (MPO) activity was higher in the cattle PMN-tachyzoite co-cultures than sheep. NETs structures released from sheep PMNs caused mechanical immobilisation of T. gondii tachyzoites, however, NET structures released from cattle PMNs may be lethal to tachyzoites. Bovine MPO may have a lethal effect on T. gondii tachyzoites in vitro during a 3h incubation. Besides other mechanisms that effect on host susceptibility to T. gondii in sheep and cattle, extracellular traps formation as a part of immunological reactions may be play a role in host susceptibility to T. gondii. Copyright © 2017 Elsevier B.V. All rights reserved.

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

PubMed

Dubey, J P; Randall, A R; Choudhary, S; Ferreira, L R; Verma, S K; Oliveira, S; Kwok, O C H; Su, C

2013-10-01

The ingestion of uncooked infected white-tailed deer (WTD) tissues can transmit Toxoplasma gondii infection to humans and mesocarnivores, including cats. In the present study, we tested 264 WTD from New Jersey for T. gondii infection during the 2011-2012 hunting season. Serum samples were tested for antibodies to T. gondii by the modified agglutination test (cutoff titer, 25); 76 (28.7%) of 264 WTD were seropositive. Heart muscle samples from 64 seropositive WTD were digested in pepsin, and the digests were bioassayed for the isolation of T. gondii . Viable T. gondii was isolated in mice from the myocardium of 9 WTD; tachyzoites from infected mouse tissues were further propagated in cell culture. One of the 9 strains was highly virulent for outbred Swiss Webster mice. The DNA isolated from culture-derived tachyzoites of these 9 T. gondii isolates was characterized using 11 PCR-RFLP markers (SAG1, 5'- and 3'-SAG2, alt.SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico). Six genotypes were found, including ToxoDB genotype no. 2 (Type III), no. 3 (Type II variant), no. 4 (Type 12), no. 216, no. 220, and no. 221. The last 2 were new genotypes that were reported for the first time. This is the first report of T. gondii infection in deer from this region of the United States.

Metallopeptidases of Toxoplasma gondii: in silico identification and gene expression.

PubMed

Escotte-Binet, Sandie; Huguenin, Antoine; Aubert, Dominique; Martin, Anne-Pascaline; Kaltenbach, Matthieu; Florent, Isabelle; Villena, Isabelle

2018-01-01

Metallopeptidases are a family of proteins with domains that remain highly conserved throughout evolution. These hydrolases require divalent metal cation(s) to activate the water molecule in order to carry out their catalytic action on peptide bonds by nucleophilic attack. Metallopeptidases from parasitic protozoa, including Toxoplasma, are investigated because of their crucial role in parasite biology. In the present study, we screened the T. gondii database using PFAM motifs specific for metallopeptidases in association with the MEROPS peptidase Database (release 10.0). In all, 49 genes encoding proteins with metallopeptidase signatures were identified in the Toxoplasma genome. An Interpro Search enabled us to uncover their domain/motif organization, and orthologs with the highest similarity by BLAST were used for annotation. These 49 Toxoplasma metallopeptidases clustered into 15 families described in the MEROPS database. Experimental expression analysis of their genes in the tachyzoite stage revealed transcription for all genes studied. Further research on the role of these peptidases should increase our knowledge of basic Toxoplasma biology and provide opportunities to identify novel therapeutic targets. This type of study would also open a path towards the comparative biology of apicomplexans. © S. Escotte-Binet et al., published by EDP Sciences, 2018.

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

First description of clonal lineage type II (genotype #1) of Toxoplasma gondii in abortion outbreak in goats.

PubMed

de Oliveira, Júnior Mário Baltazar; de Almeida, Jonatas Campos; de Melo, Renata Pimentel Bandeira; de Barros, Luiz Daniel; Garcia, João Luis; Andrade, Müller Ribeiro; Porto, Wagnner José Nascimento; Regidor-Cerrillo, Javier; Ortega-Mora, Luis Miguel; Oliveira, Andréa Alice da Fonseca; Mota, Rinaldo Aparecido

2018-05-01

The purpose of this study was to perform genotypic characterization and to evaluate the virulence of Toxoplasma gondii obtained from aborted fetuses in an abortion outbreak in goats from northeastern Brazil. Brain samples from 32 fetuses were submitted to mouse bioassay for T. gondii isolation. Two isolates were obtained and subjected to genotypic characterization. Isolate virulence was evaluated using murine model in different doses (from 10 5 to 10 1 tachyzoites/mL). In genotyping, both isolates were classified as clonal lineage type II (genotype #1 ToxoDB) and showed to be virulent for mice. This is the first description of genotype #1 in cases of goat abortion, showing the circulation of virulent T. gondii isolate producing reproductive disorders in pregnant goat. Copyright © 2018 Elsevier Inc. All rights reserved.

Distinct Strains of Toxoplasma gondii Feature Divergent Transcriptomes Regardless of Developmental Stage

DOE PAGES

Croken, Matthew; Ma, Yan Fen; Markillie, Lye Meng; ...

2014-11-13

Using high through-put RNA sequencing, we assayed the transcriptomes of three different strains of Toxoplasma gondii representing three common genotypes under both in vitro tachyzoite and in vitro bradyzoite-inducing alkaline stress culture conditions. Strikingly, the differences in transcriptional profiles between the strains, RH, PLK, and CTG, is much greater than differences between tachyzoites and alkaline stressed in vitro bradyzoites. With an FDR of 10%, we identify 241 genes differentially expressed between CTG tachyzoites and in vitro bradyzoites, including 5 putative AP2 transcription factors. We also observe close association between cell cycle regulated genes and differentiation. By Gene Set Enrichment Analysismore » (GSEA), there are a number of KEGG pathways associated with the in vitro bradyzoite transcriptomes of PLK and CTG, including pyrimidine metabolism and DNA replication. These functions are likely associated with cell-cycle arrest. When comparing mRNA levels between strains, we identify 1,526 genes that are differentially expressed regardless of culture-condition as well as 846 differentially expressed only in bradyzoites and 542 differentially expressed only in tachyzoites between at least two strains. Using GSEA, we identify ribosomal proteins as being expressed at significantly higher levels in the CTG strain than in either the RH or PLK strains. This association holds true regardless of life cycle stage.« less

Molecular analysis of Toxoplasma gondii Surface Antigen 1 (SAG1) gene cloned from Toxoplasma gondii DNA isolated from Javanese acute toxoplasmosis

NASA Astrophysics Data System (ADS)

Haryati, Sri; Agung Prasetyo, Afiono; Sari, Yulia; Dharmawan, Ruben

2018-05-01

Toxoplasma gondii Surface Antigen 1 (SAG1) is often used as a diagnostic tool due to its immunodominant-specific as antigen. However, data of the Toxoplasma gondii SAG1 protein from Indonesian isolate is limited. To study the protein, genomic DNA was isolated from a Javanese acute toxoplasmosis blood samples patient. A complete coding sequence of Toxoplasma gondii SAG1 was cloned and inserted into an Escherichia coli expression plasmid and sequenced. The sequencing results were subjected to bioinformatics analysis. The Toxoplasma gondii SAG1 complete coding sequences were successfully cloned. Physicochemical analysis revealed the 336 aa of SAG1 had 34.7 kDa of weight. The isoelectric point and aliphatic index were 8.4 and 78.4, respectively. The N-terminal methionine half-life in Escherichia coli was more than 10 hours. The antigenicity, secondary structure, and identification of the HLA binding motifs also had been discussed. The results of this study would contribute information about Toxoplasma gondii SAG1 and benefits for further works willing to develop diagnostic and therapeutic strategies against the parasite.

Toxoplasma gondii

USDA-ARS?s Scientific Manuscript database

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...

Isolation and molecular characterization of Toxoplasma gondii from captive slender-tailed meerkats (Suricata suricatta) with fatal toxoplasmosis in Argentina.

PubMed

Basso, W; Moré, G; Quiroga, M A; Pardini, L; Bacigalupe, D; Venturini, L; Valenzuela, M C; Balducchi, D; Maksimov, P; Schares, G; Venturini, M C

2009-05-12

In this study, the diagnosis of fatal disseminated toxoplasmosis in three captive slender-tailed meerkats (Suricata suricatta) in the zoo of La Plata, Argentina and the invitro isolation and molecular characterization of Toxoplasma gondii are reported. The animals showed depression, dyspnea and hypothermia, and also ataxia in one case, and died within 1-5 days. The main histopathological lesions included interstitial pneumonia, non-suppurative inflammatory changes and focal necrosis in liver, spleen, kidney and brain. Tachyzoites or tissue cysts were present in lung, liver, spleen, brain, striated muscle, kidney, intestine and mesenteric lymph node sections, and stained strongly with T. gondii antiserum in immunohistochemical analysis. T. gondii was isolated in Swiss mice and in bovine monocytes cultures from tissues of one of the meerkats. The isolate was cryopreserved and it was named TG-Suricata-1. T. gondii DNA was demonstrated in tissues of all three animals and in tachyzoites isolated in cell cultures. The PCR-RFLP analysis of markers based in the loci 3'-SAG2, 5'-SAG2, BTUB, GRA6, SAG3, c22-8, L358, PK1, c29-2 and Apico of T. gondii produced patterns corresponding to the clonal type III. Type III strains of T. gondii possess no or only little virulence in the mouse model, however their association with virulence in other animal species is uncertain. In the present case, T. gondii of the clonal lineage III was responsible for fatal cases in S. suricatta. To our knowledge, this is the first report of isolation and genotyping of T. gondii from S. suricatta.

Confocal microscope is able to detect calcium metabolic in neuronal infection by toxoplasma gondii

NASA Astrophysics Data System (ADS)

Sensusiati, A. D.; Priya, T. K. S.; Dachlan, Y. P.

2017-05-01

Calcium metabolism plays a very important role in neurons infected by Toxoplasma. Detection of change of calcium metabolism of neuron infected by Toxoplasma and Toxoplasma requires the calculation both quantitative and qualitative method. Confocal microscope has the ability to capture the wave of the fluorescent emission of the fluorescent dyes used in the measurement of cell calcium. The purpose of this study was to prove the difference in calcium changes between infected and uninfected neurons using confocal microscopy. Neuronal culture of human-skin-derived neural stem cell were divided into 6 groups, consisting 3 uninfected groups and 3 infected groups. Among the 3 groups were 2 hours, 24 hours and 48 hours. The neuron Toxoplasma gondii ratio was 1:5. Observation of intracellular calcium of neuron and tachyzoite, evidence of necrosis, apoptosis and the expression of Hsp 70 of neuron were examined by confocal microscope. The normality of the data was analysed by Kolmogorov-Smirnov Test, differentiation test was checked by t2 Test, and ANOVAs, for correlation test was done by Pearson Correlation Test. The calcium intensity of cytosolic neuron and T. gondii was significantly different from control groups (p<0.05). There was also significant correlation between calcium intensity with the evidence of necrosis and Hsp70 expression at 2 hours after infection. Apoptosis and necrosis were simultaneously shown with calcium contribution in this study. Confocal microscopy can be used to measure calcium changes in infected and uninfected neurons both in quantitatively and qualitatively.

[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.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vieira da Silva, Claudio; Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de Sao Paulo, Rua Botucatu, 862, 6o andar, 04023-062 Sao Paulo, SP; Alves da Silva, Erika

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 RHmore » 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.« less

Production, characterization and applications for Toxoplasma gondii-specific polyclonal chicken egg yolk immunoglobulins.

PubMed

Ferreira Júnior, Álvaro; Santiago, Fernanda M; Silva, Murilo V; Ferreira, Flávia B; Macêdo Júnior, Arlindo G; Mota, Caroline M; Faria, Matheus S; Silva Filho, Hercílio H; Silva, Deise A O; Cunha-Júnior, Jair P; Mineo, José R; Mineo, Tiago W P

2012-01-01

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. 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. 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.

Effect of 3-Bromopyruvate and Atovaquone on Infection during In Vitro Interaction of Toxoplasma gondii and LLC-MK2 Cells

PubMed Central

de Lima, Loyze Paola O.; Seabra, Sergio H.; Carneiro, Henrique

2015-01-01

Toxoplasma gondii infection can be severe during pregnancy and in immunocompromised patients. Current therapies for toxoplasmosis are restricted to tachyzoites and have little or no effect on bradyzoites, which are maintained in tissue cysts. Consequently, new therapeutic alternatives have been proposed as the use of atovaquone has demonstrated partial efficacy against tachyzoites and bradyzoites. This work studies the effect of 3-bromopyruvate (3-BrPA), a compound that is being tested against cancer cells, on the infection of LLC-MK2 cells with T. gondii tachyzoites, RH strain. No effect of 3-BrPA on host cell proliferation or viability was observed, but it inhibited the proliferation of T. gondii. The incubation of cultures with lectin Dolichos biflorus agglutinin (DBA) showed the development of cystogenesis, and an ultrastructural analysis of parasite intracellular development confirmed morphological characteristics commonly found in tissue cysts. Moreover, the presence of degraded parasites and the influence of 3-BrPA on endodyogeny were observed. Infected cultures were alternatively treated with a combination of this compound plus atovaquone. This resulted in a 73% reduction in intracellular parasites after 24 h of treatment and a 71% reduction after 48 h; cyst wall formation did not occur in these cultures. Therefore, we conclude that the use of 3-BrPA may serve as an important tool for the study of (i) in vitro cystogenesis; (ii) parasite metabolism, requiring a deeper understanding of the target of action of this compound on T. gondii; (iii) the alternative parasite metabolic pathways; and (iv) the molecular/cellular mechanisms that trigger parasite death. PMID:26077255

Diagnosis and treatment of Neospora caninum--associated dermatitis in a red fox (Vulpes vulpes) with concurrent Toxoplasma gondii infection.

PubMed

Duhey, Jitender P; Whitesell, Leah E; Culp, William E; Daye, Sharon

2014-06-01

A 3-mo-old red fox (Vulpes vulpes) developed generalized crusty plaques on its body during rehabilitation after an automobile accident requiring amputation of one leg. Histologic examination of skin lesion biopsy revealed granulomatous dermatitits with many intralesional protozoal tachyzoites. The protozoa stained positively with antibodies to Neospora caninum but not to Toxoplasma gondii. Treatment with clindamycin hydrochloride (10 mg/kg, twice daily, s.c.) for 1 mo completely resolved lesions, and protozoa were not demonstrable in biopsy of skin after treatment. The fox had agglutinating antibodies to T. gondii (modified agglutination test, titer 1:3200) and N. caninum (Neospora agglutination test, titer 1:25), and viable T. gondii (genotype III) was isolated from the skin biopsy after treatment. This is the first report of clinical neosporosis in a wild canid.

Imidazo[1,2-b]pyridazines targeting Toxoplasma gondii calcium-dependent protein kinase 1 decrease the parasite burden in mice with acute toxoplasmosis.

PubMed

Moine, Espérance; Moiré, Nathalie; Dimier-Poisson, Isabelle; Brunet, Kévin; Couet, William; Colas, Cyril; Van Langendonck, Nathalie; Enguehard-Gueiffier, Cécile; Gueiffier, Alain; Héraut, Bruno; Denevault-Sabourin, Caroline; Debierre-Grockiego, Françoise

2018-06-01

The current therapeutic arsenal for toxoplasmosis is restricted to drugs non-specific to the parasite which cause important side effects. Development of more efficient and specific anti-Toxoplasma compounds is urgently needed. Imidazo[1,2-b]pyridazines designed to inhibit the calcium-dependent protein kinase 1 of Toxoplasma gondii (TgCDPK1) and effective against tachyzoite growth in vitro at submicromolar ranges were modified into hydrochloride salts to be administered in vivo in a mouse model of acute toxoplasmosis. All protonated imidazo[1,2-b]pyridazine salts (SP230, SP231 and SP232) maintained their activity on TgCDPK1 and T. gondii tachyzoites. Rat and mouse liver microsomes were used to predict half-life and intrinsic clearance, and the pharmacokinetic profile of the most rapidly degraded imidazo[1,2b]pyridazine salt (SP230) was determined in serum, brain and lungs of mice after a single administration of 50 mg/kg. Compounds were then tested in vivo in a murine model of acute toxoplasmosis. Mice infected with tachyzoites of the ME49 strain of T. gondii were treated for 4, 7 or 8 days with 25 or 50 mg/kg/day of SP230, SP231 or SP232. The parasite burdens were strongly diminished (>90% reduction under some conditions) in the spleen and the lungs of mice treated with imidazo[1,2-b]pyridazine salts compared with untreated mice, without the need for pre-treatment. Moreover, no increases in the levels of hepatic and renal toxicity markers were observed, demonstrating no significant signs of short-term toxicity. To conclude, imidazo[1,2-b]pyridazine salts have strong efficacy in vivo on acute toxoplasmosis and should be further tested in a model of mouse congenital toxoplasmosis. Copyright © 2018 Australian Society for Parasitology. Published by Elsevier Ltd. All rights reserved.

The Epigenome, Cell Cycle, and Development in Toxoplasma.

PubMed

Kim, Kami

2018-06-22

Toxoplasma gondii is a common veterinary and human pathogen that persists as latent bradyzoite forms within infected hosts. The ability of the parasite to interconvert between tachyzoite and bradyzoite is key for pathogenesis of toxoplasmosis, particularly in immunocompromised individuals. The transition between tachyzoites and bradyzoites is epigenetically regulated and coupled to the cell cycle. Recent epigenomic studies have begun to elucidate the chromatin states associated with developmental switches in T. gondii. Evidence is also emerging that AP2 transcription factors both activate and repress the bradyzoite developmental program. Further studies are needed to understand the mechanisms by which T. gondii transduces environmental signals to coordinate the epigenetic and transcriptional machinery that are responsible for tachyzoite-bradyzoite interconversion. Expected final online publication date for the Annual Review of Microbiology Volume 72 is September 8, 2018. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Elucidating pathways of Toxoplasma gondii invasion in the gastrointestinal tract: involvement of the tight junction protein occludin.

PubMed

Weight, Caroline M; Jones, Emily J; Horn, Nikki; Wellner, Nikolaus; Carding, Simon R

2015-10-01

Toxoplasma gondii is an obligate intracellular parasite infecting one third of the world's population. The small intestine is the parasite's primary route of infection, although the pathway of epithelium transmigration remains unclear. Using an in vitro invasion assay and live imaging we showed that T. gondii (RH) tachyzoites infect and transmigrate between adjacent intestinal epithelial cells in polarized monolayers without altering barrier integrity, despite eliciting the production of specific inflammatory mediators and chemokines. During invasion, T. gondii co-localized with occludin. Reducing the levels of endogenous cellular occludin with specific small interfering RNAs significantly reduced the ability of T. gondii to penetrate between and infect epithelial cells. Furthermore, an in vitro invasion and binding assays using recombinant occludin fragments established the capacity of the parasite to bind occludin and in particular to the extracellular loops of the protein. These findings provide evidence for occludin playing a role in the invasion of T. gondii in small intestinal epithelial cells. Copyright © 2015 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

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.

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.

In vitro action of antiparasitic drugs, especially artesunate, against Toxoplasma gondii.

PubMed

Gomes, Thaís Cobellis; de Andrade Júnior, Heitor Franco; Lescano, Susana Angélica Zevallos; Amato-Neto, Vicente

2012-01-01

Toxoplasmosis is usually a benign infection, except in the event of ocular, central nervous system (CNS), or congenital disease and particularly when the patient is immunocompromised. Treatment consists of drugs that frequently cause adverse effects; thus, newer, more effective drugs are needed. In this study, the possible activity of artesunate, a drug successfully being used for the treatment of malaria, on Toxoplasma gondii growth in cell culture is evaluated and compared with the action of drugs that are already being used against this parasite. LLC-MK2 cells were cultivated in RPMI medium, kept in disposable plastic bottles, and incubated at 36ºC with 5% CO2. Tachyzoites of the RH strain were used. The following drugs were tested: artesunate, cotrimoxazole, pentamidine, pyrimethamine, quinine, and trimethoprim. The effects of these drugs on tachyzoites and LLC-MK2 cells were analyzed using nonlinear regression analysis with Prism 3.0 software. Artesunate showed a mean tachyzoite inhibitory concentration (IC50) of 0.075µM and an LLC MK2 toxicity of 2.003µM. Pyrimethamine was effective at an IC50 of 0.482µM and a toxicity of 11.178µM. Trimethoprim alone was effective against the in vitro parasite. Cotrimoxazole also was effective against the parasite but at higher concentrations than those observed for artesunate and pyrimethamine. Pentamidine and quinine had no inhibitory effect over tachyzoites. Artesunate is proven in vitro to be a useful alternative for the treatment of toxoplasmosis, implying a subsequent in vivo effect and suggesting the mechanism of this drug against the parasite.

Novel Fitc-Labeled Igy Antibody: Fluorescence Imaging Toxoplasma Gondii In Vitro.

PubMed

Sert, Mehtap; Cakir Koc, Rabia; Budama Kilinc, Yasemin

2017-04-12

Toxoplasmosis is caused by T. gondii and can create serious health problems in humans and also worldwide economic harm. Because of the clinical and veterinary importance of toxoplasmosis, its timely and accurate diagnosis has a major impact on disease-fighting strategies. T. gondii surface antigen 1 (SAG1), an immunodominant-specific antigen, is often used as a diagnostic tool. Therefore, the aim of this study was the optimization of novel fluorescein isothiocyanate (FITC) labeling of the SAG1-specific IgY antibody to show the potential for immunofluorescence imaging of T. gondii in vitro. The specificity of IgY antibodies was controlled by an enzyme-linked immunosorbent assay (ELISA), and the concentration of the IgY antibody was detected using a spectrophotometer. The optimum incubation time and FITC concentration were determined with a fluorescence spectrometer. The obtained FITC-labeled IgY was used for marking T. gondii tachyzoites, which were cultured in vitro and viewed using light microscopy. The interaction of the fluorescence-labeled antibody and the T. gondii tachyzoites was examined with a fluorescence microscope. In this study, for the first time, a FITC-labeled anti-SAG1 IgY antibody was developed according to ELISA, fluorescence spectrometer, and fluorescence imaging of cell culture. In the future, the obtained FITC-labeled T. gondii tachyzoites' specific IgY antibodies may be used as diagnostic tools for the detection of T. gondii infections in different samples.

Molecular docking to Toxoplasma gondii thymidylate synthase-dihydrofolate reductase and efficacy of raltitrexed in infected mice.

PubMed

de Paula Reis, Michelle; de Lima, Daniely Alves; Pauli, Karoline Bach; Andreotti, Carlos Eduardo Linhares; de Moraes, André Luiz Soares; Gonçalves, Daniela Dib; Navarro, Italmar Teodorico; Bueno, Paulo Sérgio Alves; Seixas, Flavio Augusto Vicente; Gasparotto Junior, Arquimedes; Lourenço, Emerson Luiz Botelho

2018-05-01

Toxoplasmosis is a zoonosis of worldwide distribution. Currently, two drugs, pyrimethamine and sulfadiazine, are used as a reference in the treatment of toxoplasmosis, but the resistance of Toxoplasma gondii appears as a relevant public health problem. In order to identify new drugs to toxoplasmosis treatment, we performed a molecular docking of raltitrexed to T. gondii thymidylate synthase-dihydrofolate reductase (TS-DHFR) and also evaluated its efficacy in infected mice. Initially, raltitrexed was docked on the crystallographic structures of TS-DHFR from T. gondii and Mus musculus. Then, 48 h after infection with the T. gondii RH strain, different groups of mice received an oral dose of raltitrexed (0.15, 0.75, and 1.5 mg kg -1 ). Two days after treatments, raltitrexed was able to prevent mortality and reduce the number of tachyzoites in the peritoneal fluid and liver imprints from infected mice. The results showed that raltitrexed has important protective activities against the T. gondii RH strain. Molecular docking still suggests that the effects against the parasite may be dependent on the inhibition of T. gondii thymidylate synthase. This study opens new perspectives for the use of raltitrexed in patients infected with T. gondii, especially when conventional treatments do not exhibit the expected efficacy.

Toxoplasma gondii: isolation, biological and molecular characterisation of samples from free-range Gallus gallus domesticus from countryside Southeast Brazil.

PubMed

Ferreira, Tamiris Cristine Ribeiro; Buery, Julyana Cerqueira; Moreira, Narcisa Imaculada Brant; Santos, Claudiney Biral; Costa, Júlia Gatti Ladeia; Pinto, Lorena Velozo; Baraviera, Ramon Castro de Araújo; Vitor, Ricardo Wagner Almeida; Fux, Blima

2018-05-24

Toxoplasma gondii presents a high prevalence worldwide, infecting several animals. Felines are considered the definitive hosts and among the intermediate hosts we highlight mammals and birds. The man can become infected by ingesting tissue cysts present in birds and mammals. Biological and molecular aspects of T. gondii allows a better understanding of the epidemiology of toxoplasmosis. This work is a serologic screening of 58 chickens grown (Gallus gallus domesticus) for human consumption in Espírito Santo State, by means of indirect haemagglutination assay (IHA). Thirteen chickens tested positive for anti-T. gondii antibodies. The heart and brain of five positive chickens were harvested, treated with pepsin and inoculated separately, in two Swiss mice, intraperitoneally. Tachyzoites were observed in the peritoneum of all the animals, between seven and 10 days after the inoculum. Ten isolates were obtained and biologically characterised in BALB/c mice inoculated with 101 to 104 tachyzoites. All isolates were classified as virulent or intermediately virulent. Isolates were genotyped by means of polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis, revealing three different genotypes. None of the isolates exhibited the clonal type I, II or III genotype. No genotypic differences were observed between the isolates from the brain or heart from the same bird.

Effects of Extracts from Thai Piperaceae Plants against Infection with Toxoplasma gondii

PubMed Central

Leesombun, Arpron; Boonmasawai, Sookruetai; Shimoda, Naomi; Nishikawa, Yoshifumi

2016-01-01

Herbal medicines and natural herb extracts are widely used as alternative treatments for various parasitic diseases, and such extracts may also have potential to decrease the side effects of the standard regimen drugs used to treat toxoplasmosis (sulfadiazine-pyrimethamine combination). We evaluated how effective the Thai piperaceae plants Piper betle, P. nigrum and P. sarmentosum are against Toxoplasma gondii infection in vitro and in vivo. Individually, we extracted the piperaceae plants with ethanol, passed them through a rotary evaporator and then lyophilized them to obtain crude extracts for each one. The in vitro study indicated that the P. betle extract was the most effective extract at inhibiting parasite growth in HFF cells (IC50 on RH-GFP: 23.2 μg/mL, IC50 on PLK-GFP: 21.4 μg/mL). Furthermore, treatment of experimental mice with the P. betle extract for 7 days after infection with 1,000 tachyzoites of the T. gondii PLK strain increased their survival (survival rates: 100% in 400 mg/kg-treated, 83.3% in 100 mg/kg-treated, 33.3% in 25 mg/kg-treated, 33.3% in untreated mice). Furthermore, treatment with 400 mg/kg of the P. betle extract resulted in 100% mouse survival following infection with 100,000 tachyzoites. The present study shows that P. betle extract has the potential to act as a medical plant for the treatment of toxoplasmosis. PMID:27213575

Fatal toxoplasmosis in an immunosuppressed domestic cat from Brazil caused by Toxoplasma gondii clonal type I.

PubMed

Pena, Hilda Fátima de Jesus; Evangelista, Camila Mariellen; Casagrande, Renata Assis; Biezus, Giovana; Wisser, Claudia Salete; Ferian, Paulo Eduardo; Moura, Anderson Barbosa de; Rolim, Veronica Machado; Driemeier, David; Oliveira, Solange; Alves, Bruna Farias; Gennari, Solange Maria; Traverso, Sandra Davi

2017-01-01

The objective of the study was to report on a fatal case of feline toxoplasmosis with coinfection with the feline leukemia virus (FeLV). A domestic cat (Felis silvestris catus) presented intense dyspnea and died three days later. In the necropsy, the lungs were firm, without collapse and with many white areas; moderate lymphadenomegaly and splenomegaly were also observed. The histopathological examination showed severe necrotic interstitial bronchopneumonia and mild necrotic hepatitis, associated with intralesional cysts and tachyzoites of Toxoplasma gondii that were positive by anti-T. gondii immunohistochemical (IHC) evaluation. The bone marrow showed chronic myeloid leukemia and the neoplastic cells were positive by anti-FeLV IHC evaluation. DNA extracted from lungs was positive for T. gondii by PCR targeting REP-529. T. gondii was characterized by PCR-RFLP and by the microsatellites technique. ToxoDB-PCR-RFLP #10, i.e. the archetypal type I, was identified. Microsatellite analysis showed that the strain was a variant of type I with two atypical alleles. This was the first time that a T. gondii clonal type I genotype was correlated with a case of acute toxoplasmosis in a host in Brazil.

Effect of 3-bromopyruvate and atovaquone on infection during in vitro interaction of Toxoplasma gondii and LLC-MK2 cells.

PubMed

de Lima, Loyze Paola O; Seabra, Sergio H; Carneiro, Henrique; Barbosa, Helene S

2015-09-01

Toxoplasma gondii infection can be severe during pregnancy and in immunocompromised patients. Current therapies for toxoplasmosis are restricted to tachyzoites and have little or no effect on bradyzoites, which are maintained in tissue cysts. Consequently, new therapeutic alternatives have been proposed as the use of atovaquone has demonstrated partial efficacy against tachyzoites and bradyzoites. This work studies the effect of 3-bromopyruvate (3-BrPA), a compound that is being tested against cancer cells, on the infection of LLC-MK2 cells with T. gondii tachyzoites, RH strain. No effect of 3-BrPA on host cell proliferation or viability was observed, but it inhibited the proliferation of T. gondii. The incubation of cultures with lectin Dolichos biflorus agglutinin (DBA) showed the development of cystogenesis, and an ultrastructural analysis of parasite intracellular development confirmed morphological characteristics commonly found in tissue cysts. Moreover, the presence of degraded parasites and the influence of 3-BrPA on endodyogeny were observed. Infected cultures were alternatively treated with a combination of this compound plus atovaquone. This resulted in a 73% reduction in intracellular parasites after 24 h of treatment and a 71% reduction after 48 h; cyst wall formation did not occur in these cultures. Therefore, we conclude that the use of 3-BrPA may serve as an important tool for the study of (i) in vitro cystogenesis; (ii) parasite metabolism, requiring a deeper understanding of the target of action of this compound on T. gondii; (iii) the alternative parasite metabolic pathways; and (iv) the molecular/cellular mechanisms that trigger parasite death. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

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

Role of an estradiol regulatory factor-hydroxysteroid dehydrogenase (HSD) in Toxoplasma gondii infection and pathogenicity.

PubMed

Zhang, Xiao; Liu, Jing; Li, Muzi; Fu, Yong; Zhang, Taotao; Han, Qian; Liu, Qun

2017-11-01

Toxoplasma gondii is an apicomplexan parasite that infects most species of warm-blooded animals, including humans, and causes abortions and severe damage to the fetal central nervous system. During pregnancy, the prevalence of toxoplasmosis increases throughout the second and third quarter of gestation, while the hormones progesterone and estradiol simultaneously increase. Thus, it has been suggested that these hormones could affect parasite reproduction. This study was mainly focused on an estradiol regulatory factor-Hydroxysteroid dehydrogenase (HSD) gene in T. gondii. Our data showed that estradiol promoted Pru (Type II) and VEG (Type III) infection and thus significantly contributed to the pathogenicity of T. gondii in mice. Subsequently, we found that this phenomenon may relate to the interplay of T. gondii and estradiol. We reported that estradiol can enter T. gondii tachyzoites. Bioinformatics analysis showed that T. gondii may have a residual estradiol metabolism-related gene HSD. To verify the gene function, HEK293T cells were transiently transfected with Tg-HSD and gene expression was induced. Then, HPLC (high-performance liquid chromatography) analysis showed that Tg-HSD can efficiently transform estrone into estradiol. Moreover, Tg-HSD -overexpressing parasites showed significantly enhanced pathogenicity and upregulation of estradiol levels in mice. In conclusion, estradiol can promote T. gondii infection in vitro and in vivo, and this may be related to its Tg- HSD gene. Copyright © 2017 Elsevier Ltd. All rights reserved.

Isolation and genetic characterization of Toxoplasma gondii from striped dolphin (Stenella coeruleoalba) from Costa Rica.

PubMed

Dubey, J P; Morales, J A; Sundar, N; Velmurugan, G V; González-Barrientos, C R; Hernández-Mora, G; Su, C

2007-06-01

Toxoplasma gondii infection in marine mammals is of interest because of mortality and mode of transmission. It has been suggested that marine mammals become infected with T. gondii oocysts washed from land to the sea. We report the isolation and genetic characterization of viable T. gondii from a striped dolphin (Stenella coeruleoalba), the first time from this host. An adult female dolphin was found stranded on the Pacific Coast of Costa Rica, and the animal died the next day. The dolphin had a high (1:6400) antibody titer to T. gondii in the modified agglutination test. Severe nonsuppurative meningoencephalomyelitis was found in its brain and spinal cord, but T. gondii was not found in histological sections of the dolphin. Portions of its brain and the heart were bioassayed in mice for the isolation of T. gondii. Viable T. gondii was isolated from the brain, but not from the heart, of the dolphin. A cat fed mice infected with the dolphin isolate (designated TgSdCol) shed oocysts. Genomic DNA from tachyzoites of this isolate was used for genotyping at 10 genetic loci, including SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico, and this TgSdCo1 isolate was found to be Type II.

An atypical genotype of Toxoplasma gondii as a cause of mortality in Hector's dolphins (Cephalorhynchus hectori).

PubMed

Roe, W D; Howe, L; Baker, E J; Burrows, L; Hunter, S A

2013-02-18

Hector's dolphins (Cephalorhynchus hectori) are a small endangered coastal species that are endemic to New Zealand. Anthropogenic factors, particularly accidental capture in fishing nets, are believed to be the biggest threat to survival of this species. The role of infectious disease as a cause of mortality has not previously been well investigated. This study investigates Toxoplasma gondii infection in Hector's dolphins, finding that 7 of 28 (25%) dolphins examined died due to disseminated toxoplasmosis, including 2 of 3 Maui's dolphins, a critically endangered sub-species. A further 10 dolphins had one or more tissues that were positive for the presence of T. gondii DNA using PCR. Genotyping revealed that 7 of 8 successfully amplified isolates were an atypical Type II genotype. Fatal cases had necrotising and haemorrhagic lesions in the lung (n=7), lymph nodes (n=6), liver (n=4) and adrenals (n=3). Tachyzoites and tissue cysts were present in other organs including the brain (n=5), heart (n=1), stomach (n=1) and uterus (n=1) with minimal associated inflammatory response. One dolphin had a marked suppurative metritis in the presence of numerous intra-epithelial tachyzoites. No dolphins had underlying morbillivirus infection. This study provides the first evidence that infectious agents could be important in the population decline of this species, and highlights the need for further research into the route of entry of T. gondii organisms into the marine environment worldwide. Copyright © 2012 Elsevier B.V. All rights reserved.

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

Differential Roles for Inner Membrane Complex Proteins across Toxoplasma gondii and Sarcocystis neurona Development

PubMed Central

Dubey, Rashmi; Harrison, Brooke; Dangoudoubiyam, Sriveny; Bandini, Giulia; Cheng, Katherine; Kosber, Aziz; Agop-Nersesian, Carolina; Howe, Daniel K.; Samuelson, John; Ferguson, David J. P.

2017-01-01

ABSTRACT The inner membrane complex (IMC) of apicomplexan parasites contains a network of intermediate filament-like proteins. The 14 alveolin domain-containing IMC proteins in Toxoplasma gondii fall into different groups defined by their distinct spatiotemporal dynamics during the internal budding process of tachyzoites. Here, we analyzed representatives of different IMC protein groups across all stages of the Toxoplasma life cycle and during Sarcocystis neurona asexual development. We found that across asexually dividing Toxoplasma stages, IMC7 is present exclusively in the mother’s cytoskeleton, whereas IMC1 and IMC3 are both present in mother and daughter cytoskeletons (IMC3 is strongly enriched in daughter buds). In developing macro- and microgametocytes, IMC1 and -3 are absent, whereas IMC7 is lost in early microgametocytes but retained in macrogametocytes until late in their development. We found no roles for IMC proteins during meiosis and sporoblast formation. However, we observed that IMC1 and IMC3, but not IMC7, are present in sporozoites. Although the spatiotemporal pattern of IMC15 and IMC3 suggests orthologous functions in Sarcocystis, IMC7 may have functionally diverged in Sarcocystis merozoites. To functionally characterize IMC proteins, we knocked out IMC7, -12, -14, and -15 in Toxoplasma. IMC14 and -15 appear to be involved in switching between endodyogeny and endopolygeny. In addition, IMC7, -12, and -14, which are all recruited to the cytoskeleton outside cytokinesis, are critical for the structural integrity of extracellular tachyzoites. Altogether, stage- and development-specific roles for IMC proteins can be discerned, suggesting different niches for each IMC protein across the entire life cycle. IMPORTANCE The inner membrane complex (IMC) is a defining feature of apicomplexan parasites key to both their motility and unique cell division. To provide further insights into the IMC, we analyzed the dynamics and functions of representative

Differential Roles for Inner Membrane Complex Proteins across Toxoplasma gondii and Sarcocystis neurona Development.

PubMed

Dubey, Rashmi; Harrison, Brooke; Dangoudoubiyam, Sriveny; Bandini, Giulia; Cheng, Katherine; Kosber, Aziz; Agop-Nersesian, Carolina; Howe, Daniel K; Samuelson, John; Ferguson, David J P; Gubbels, Marc-Jan

2017-01-01

The inner membrane complex (IMC) of apicomplexan parasites contains a network of intermediate filament-like proteins. The 14 alveolin domain-containing IMC proteins in Toxoplasma gondii fall into different groups defined by their distinct spatiotemporal dynamics during the internal budding process of tachyzoites. Here, we analyzed representatives of different IMC protein groups across all stages of the Toxoplasma life cycle and during Sarcocystis neurona asexual development. We found that across asexually dividing Toxoplasma stages, IMC7 is present exclusively in the mother's cytoskeleton, whereas IMC1 and IMC3 are both present in mother and daughter cytoskeletons (IMC3 is strongly enriched in daughter buds). In developing macro- and microgametocytes, IMC1 and -3 are absent, whereas IMC7 is lost in early microgametocytes but retained in macrogametocytes until late in their development. We found no roles for IMC proteins during meiosis and sporoblast formation. However, we observed that IMC1 and IMC3, but not IMC7, are present in sporozoites. Although the spatiotemporal pattern of IMC15 and IMC3 suggests orthologous functions in Sarcocystis , IMC7 may have functionally diverged in Sarcocystis merozoites. To functionally characterize IMC proteins, we knocked out IMC7, -12, -14, and -15 in Toxoplasma . IMC14 and -15 appear to be involved in switching between endodyogeny and endopolygeny. In addition, IMC7, -12, and -14, which are all recruited to the cytoskeleton outside cytokinesis, are critical for the structural integrity of extracellular tachyzoites. Altogether, stage- and development-specific roles for IMC proteins can be discerned, suggesting different niches for each IMC protein across the entire life cycle. IMPORTANCE The inner membrane complex (IMC) is a defining feature of apicomplexan parasites key to both their motility and unique cell division. To provide further insights into the IMC, we analyzed the dynamics and functions of representative alveolin

Multicenter Comparative Evaluation of Five Commercial Methods for Toxoplasma DNA Extraction from Amniotic Fluid▿

PubMed Central

Yera, H.; Filisetti, D.; Bastien, P.; Ancelle, T.; Thulliez, P.; Delhaes, L.

2009-01-01

Over the past few years, a number of new nucleic acid extraction methods and extraction platforms using chemistry combined with magnetic or silica particles have been developed, in combination with instruments to facilitate the extraction procedure. The objective of the present study was to investigate the suitability of these automated methods for the isolation of Toxoplasma gondii DNA from amniotic fluid (AF). Therefore, three automated procedures were compared to two commercialized manual extraction methods. The MagNA Pure Compact (Roche), BioRobot EZ1 (Qiagen), and easyMAG (bioMérieux) automated procedures were compared to two manual DNA extraction kits, the QIAamp DNA minikit (Qiagen) and the High Pure PCR template preparation kit (Roche). Evaluation was carried out with two specific Toxoplasma PCRs (targeting the 529-bp repeat element), inhibitor search PCRs, and human beta-globin PCRs. The samples each consisted of 4 ml of AF with or without a calibrated Toxoplasma gondii RH strain suspension (0, 1, 2.5, 5, and 25 tachyzoites/ml). All PCR assays were laboratory-developed real-time PCR assays, using either TaqMan or fluorescent resonance energy transfer probes. A total of 1,178 PCRs were performed, including 978 Toxoplasma PCRs. The automated and manual methods were similar in sensitivity for DNA extraction from T. gondii at the highest concentration (25 Toxoplasma gondii cells/ml). However, our results showed that the DNA extraction procedures led to variable efficacy in isolating low concentrations of tachyzoites in AF samples (<5 Toxoplasma gondii cells/ml), a difference that might have repercussions since low parasite concentrations in AF exist and can lead to congenital toxoplasmosis. PMID:19846633

Auranofin Is Highly Efficacious against Toxoplasma gondii In Vitro and in an In Vivo Experimental Model of Acute Toxoplasmosis

PubMed Central

Andrade, Rosa M.; Chaparro, Juan D.; Capparelli, Edmund; Reed, Sharon L.

2014-01-01

Background The mainstay of toxoplasmosis treatment targets the folate biosynthetic pathways and has not changed for the last 50 years. The activity of these chemotherapeutic agents is restricted to one lifecycle stage of Toxoplasma gondii, they have significant toxicity, and the impending threat of emerging resistance to these agents makes the discovery of new therapies a priority. We now demonstrate that auranofin, an orally administered gold containing compound that was FDA approved for treatment of rheumatoid arthritis, has activity against Toxoplasma gondii in vitro (IC50 = 0.28 µM) and in vivo (1 mg/kg). Methods/Principal Findings Replication within human foreskin fibroblasts of RH tachyzoites was inhibited by auranofin. At 0.4 µM, auranofin inhibited replication, as measured by percent infected fibroblasts at 24 hrs, (10.94% vs. 24.66% of controls; p = 0.0003) with no effect on parasite invasion (16.95% vs. 12.91% p = 0.4331). After 18 hrs, 62% of extracellular parasites treated with auranofin were non-viable compared to control using an ATP viability assay (p = 0.0003). In vivo, a previously standardized chicken embryo model of acute toxoplasmosis was used. Fourteen day old chicken embryos were injected through the chorioallantoic vein with 1×104 tachyzoites of the virulent RH strain. The treatment group received one dose of auranofin at the time of inoculation (1 mg/kg estimated body weight). On day 5, auranofin-treated chicken embryos were 100% protected against death (p = 0.0002) and had a significantly reduced parasite load as determined by histopathology, immunohistochemistry and by the number of parasites quantified by real-time PCR. Conclusions These results reveal in vitro and in vivo activity of auranofin against T. gondii, suggesting that it may be an effective alternative treatment for toxoplasmosis. PMID:25079790

Auranofin is highly efficacious against Toxoplasma gondii in vitro and in an in vivo experimental model of acute toxoplasmosis.

PubMed

Andrade, Rosa M; Chaparro, Juan D; Capparelli, Edmund; Reed, Sharon L

2014-01-01

The mainstay of toxoplasmosis treatment targets the folate biosynthetic pathways and has not changed for the last 50 years. The activity of these chemotherapeutic agents is restricted to one lifecycle stage of Toxoplasma gondii, they have significant toxicity, and the impending threat of emerging resistance to these agents makes the discovery of new therapies a priority. We now demonstrate that auranofin, an orally administered gold containing compound that was FDA approved for treatment of rheumatoid arthritis, has activity against Toxoplasma gondii in vitro (IC50 = 0.28 µM) and in vivo (1 mg/kg). Replication within human foreskin fibroblasts of RH tachyzoites was inhibited by auranofin. At 0.4 µM, auranofin inhibited replication, as measured by percent infected fibroblasts at 24 hrs, (10.94% vs. 24.66% of controls; p = 0.0003) with no effect on parasite invasion (16.95% vs. 12.91% p = 0.4331). After 18 hrs, 62% of extracellular parasites treated with auranofin were non-viable compared to control using an ATP viability assay (p = 0.0003). In vivo, a previously standardized chicken embryo model of acute toxoplasmosis was used. Fourteen day old chicken embryos were injected through the chorioallantoic vein with 1×104 tachyzoites of the virulent RH strain. The treatment group received one dose of auranofin at the time of inoculation (1 mg/kg estimated body weight). On day 5, auranofin-treated chicken embryos were 100% protected against death (p = 0.0002) and had a significantly reduced parasite load as determined by histopathology, immunohistochemistry and by the number of parasites quantified by real-time PCR. These results reveal in vitro and in vivo activity of auranofin against T. gondii, suggesting that it may be an effective alternative treatment for toxoplasmosis.

Experimental infection with the Toxoplasma gondii ME-49 strain in the Brazilian BR-1 mini pig is a suitable animal model for human toxoplasmosis.

PubMed

Miranda, Farlen José Bebber; Souza, Diogo Benchimol de; Frazão-Teixeira, Edwards; Oliveira, Fábio Conceição de; Melo, João Cardoso de; Mariano, Carlos Magno Anselmo; Albernaz, Antonio Peixoto; Carvalho, Eulógio Carlos Queiróz de; Oliveira, Francisco Carlos Rodrigues de; Souza, Wanderley de; DaMatta, Renato Augusto

2015-02-01

Toxoplasma gondii causes toxoplasmosis, a worldwide disease. Experimentation with pigs is necessary for the development of new therapeutic approaches to human diseases. BR-1 mini pigs were intramuscularly infected with T. gondii with tachyzoites (RH strain) or orally infected with cysts (ME-49 strain). Haematology and serum biochemistry were analysed and buffy coat cells were inoculated in mice to determine tachyzoite circulation. No alterations were observed in erythrocyte and platelet values; however, band neutrophils increased seven days after infection with ME-49. Serology of the mice inoculated with pig blood leucocytes revealed circulating ME-49 or RH strain tachyzoites in the pigs' peripheral blood at two and seven or nine days post-infection. The tachyzoites were also directly observed in blood smears from the infected pigs outside and inside leucocytes for longer periods. Alanine-aminotransferase was high at days 21 and 32 in the RH infected pigs. After 90 days, the pigs were euthanised and their tissue samples were processed and inoculated into mice. The mice serology revealed the presence of parasites in the hearts, ileums and mesenteric lymph nodes of the pigs. Additionally, cysts in the mice were only observed after pig heart tissue inoculation. The infected pigs presented similar human outcomes with relatively low pathogenicity and the BR-1 mini pig model infected with ME-49 is suitable to monitor experimental toxoplasmosis.

Experimental infection with the Toxoplasma gondii ME-49 strain in the Brazilian BR-1 mini pig is a suitable animal model for human toxoplasmosis

PubMed Central

Miranda, Farlen José Bebber; de Souza, Diogo Benchimol; Frazão-Teixeira, Edwards; de Oliveira, Fábio Conceição; de Melo, João Cardoso; Mariano, Carlos Magno Anselmo; Albernaz, Antonio Peixoto; de Carvalho, Eulógio Carlos Queiróz; de Oliveira, Francisco Carlos Rodrigues; de Souza, Wanderley; DaMatta, Renato Augusto

2015-01-01

Toxoplasma gondii causes toxoplasmosis, a worldwide disease. Experimentation with pigs is necessary for the development of new therapeutic approaches to human diseases. BR-1 mini pigs were intramuscularly infected with T. gondii with tachyzoites (RH strain) or orally infected with cysts (ME-49 strain). Haematology and serum biochemistry were analysed and buffy coat cells were inoculated in mice to determine tachyzoite circulation. No alterations were observed in erythrocyte and platelet values; however, band neutrophils increased seven days after infection with ME-49. Serology of the mice inoculated with pig blood leucocytes revealed circulating ME-49 or RH strain tachyzoites in the pigs' peripheral blood at two and seven or nine days post-infection. The tachyzoites were also directly observed in blood smears from the infected pigs outside and inside leucocytes for longer periods. Alanine-aminotransferase was high at days 21 and 32 in the RH infected pigs. After 90 days, the pigs were euthanised and their tissue samples were processed and inoculated into mice. The mice serology revealed the presence of parasites in the hearts, ileums and mesenteric lymph nodes of the pigs. Additionally, cysts in the mice were only observed after pig heart tissue inoculation. The infected pigs presented similar human outcomes with relatively low pathogenicity and the BR-1 mini pig model infected with ME-49 is suitable to monitor experimental toxoplasmosis. PMID:25742268

A plant/fungal-type phosphoenolpyruvate carboxykinase located in the parasite mitochondrion ensures glucose-independent survival of Toxoplasma gondii.

PubMed

Nitzsche, Richard; Günay-Esiyok, Özlem; Tischer, Maximilian; Zagoriy, Vyacheslav; Gupta, Nishith

2017-09-15

Toxoplasma gondii is considered to be one of the most successful intracellular pathogens, because it can reproduce in varied nutritional milieus, encountered in diverse host cell types of essentially any warm-blooded organism. Our earlier work demonstrated that the acute (tachyzoite) stage of T. gondii depends on cooperativity of glucose and glutamine catabolism to meet biosynthetic demands. Either of these two nutrients can sustain the parasite survival; however, what determines the metabolic plasticity has not yet been resolved. Here, we reveal two discrete phosphoenolpyruvate carboxykinase (PEPCK) enzymes in the parasite, one of which resides in the m i t ochondrion ( Tg PEPCK mt ), whereas the other protein is n ot e xpressed in t achyzoites ( Tg PEPCK net ). Parasites with an intact glycolysis can tolerate genetic deletions of Tg PEPCK mt as well as of Tg PEPCK net , indicating their nonessential roles for tachyzoite survival. Tg PEPCK net can also be ablated in a glycolysis-deficient mutant, while Tg PEPCK mt is refractory to deletion. Consistent with this, the lytic cycle of a conditional mutant of Tg PEPCK mt in the glycolysis-impaired strain was aborted upon induced repression of the mitochondrial isoform, demonstrating its essential role for the glucose-independent survival of parasites. Isotope-resolved metabolomics of the conditional mutant revealed defective flux of glutamine-derived carbon into RNA-bound ribose sugar as well as metabolites associated with gluconeogenesis, entailing a critical nodal role of PEPCK mt in linking catabolism of glucose and glutamine with anabolic pathways. Our data also suggest a homeostatic function of Tg PEPCK mt in cohesive operation of glycolysis and the tricarboxylic acid cycle in a normal glucose-replete milieu. Conversely, we found that the otherwise integrative enzyme pyruvate carboxylase ( Tg PyC) is dispensable not only in glycolysis-competent but also in glycolysis-deficient tachyzoites despite a mitochondrial

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. Copyright © 2013 Elsevier B.V. All rights reserved.

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. Copyright © 2014 Elsevier B.V. All rights reserved.

Toxoplasma Gondii and Pre-treatment Protocols for Polymerase Chain Reaction Analysis of Milk Samples: A Field Trial in Sheep from Southern Italy.

PubMed

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

2017-01-24

Toxoplasmosis is a zoonotic disease caused by the protozoan Toxoplasma gondii. Ingestion of raw milk has been suggested as a risk for transmission to humans. Here the authors evaluated pre-treatment protocols for DNA extraction on T. gondii tachyzoite-spiked sheep milk with the aim of identifying the method that resulted in the most rapid and reliable polymerase chain reaction (PCR) positivity. This protocol was then used to analyse milk samples from sheep of three different farms in Southern Italy, including real time PCR for DNA quantification and PCR-restriction fragment length polymorphism for genotyping. The pre-treatment protocol using ethylenediaminetetraacetic acid and Tris-HCl to remove casein gave the best results in the least amount of time compared to the others on spiked milk samples. One sample of 21 collected from sheep farms was positive on one-step PCR, real time PCR and resulted in a Type I genotype at one locus (SAG3). Milk usually contains a low number of tachyzoites and this could be a limiting factor for molecular identification. Our preliminary data has evaluated a rapid, cost-effective and sensitive protocol to treat milk before DNA extraction. The results of the present study also confirm the possibility of T. gondii transmission through consumption of raw milk and its unpasteurised derivatives.

Genetic diversity of Toxoplasma gondii isolates in Egyptian feral cats reveals new genotypes.

PubMed

Al-Kappany, Y M; Rajendran, C; Abu-Elwafa, S A; Hilali, M; Su, C; Dubey, J P

2010-12-01

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, 115 viable T. gondii isolates from tissues of cats from Egypt were genotyped using 10 PCR-restriction fragment length polymorphism markers (SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico) and DNA from tachyzoites. Seven genotypes were recognized including the clonal Type II, Type III (2 genotypes), and 4 atypical genotypes. Ninety percent (103 of 115) of isolates were clonal, i.e., Type II (n  =  61) and Type III (n  =  42) strains. Of the 61 Type II strains, all had the Type II alleles at all loci, except for 2 strains that had allele I at Apico. Eight isolates were divided into 4 atypical genotypes. One of these genotypes (with 4 isolates) was previously reported in dogs from Sri Lanka and in sand cats from the United Arab Emirates. Four isolates had mixed infections. These results revealed a strong clonal population structure with the dominance of clonal Type II and III lineages of T. gondii in feral cats from Egypt.

The heat shock protein 90 of Toxoplasma gondii is essential for invasion of host cells and tachyzoite growth

PubMed Central

Sun, Hongchao; Zhuo, Xunhui; Zhao, Xianfeng; Yang, Yi; Chen, Xueqiu; Yao, Chaoqun; Du, Aifang

2017-01-01

Toxoplasma gondii is an obligate intracellular apicomplexan parasite that infects almost all warm-blooded vertebrates. Heat shock proteins (HSP) regulate key signal transduction events in many organisms, and heat shock protein 90 (Hsp90) plays an important role in growth, development, and virulence in several parasitic protozoa. Here, we discovered increased transcription of the Hsp90 gene under conditions for bradyzoite differentiation, i.e. alkaline and heat shock conditions in vitro, suggesting that Hsp90 may be connected with bradyzoite development in T. gondii. A knockout of the TgHsp90 strain (ΔHsp90) and a complementation strain were constructed. The TgHsp90 knockout cells were found to be defective in host-cell invasion, were not able to proliferate in vitro in Vero cells, and did not show long-time survival in mice in vivo. These inabilities of the knockout parasites were restored upon complementation of TgHsp90. These data unequivocally show that TgHsp90 contributes to bradyzoite development, and to invasion and replication of T. gondii in host cells. PMID:28627357

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Francia, Maria E.; Wicher, Sarah; Pace, Douglas A.

2011-06-10

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

Seroepidemiology of Toxoplasma gondii infection in Tepehuanos in Durango, Mexico.

PubMed

Alvarado-Esquivel, Cosme; Estrada-Martínez, Sergio; García-López, Claudia Rosalba; Rojas-Rivera, Amparo; Sifuentes-Álvarez, Antonio; Liesenfeld, Oliver

2012-02-01

The epidemiology of Toxoplasma gondii infection is known to depend on a number of behavioral factors, including contact with animals and eating habits. The epidemiology in specific populations (i.e., in indigenous ethnic groups) is not well studied. We therefore investigated the presence of anti-Toxoplasma IgG and IgM antibodies in 156 Tepehuanos, an indigenous ethnic group in Durango State in northern Mexico, using ELISAs. Of the 156 Tepehuanos (mean age 31.03±16.71 years), 35 (22.4%) had anti-Toxoplasma IgG antibodies. IgG levels of 14-99, 100-150, and >150 IU/mL were found in 15 (42.9%), 1 (2.8%), and 19 (54.3%) anti-Toxoplasma IgG-positive Tepehuanos, respectively. Also, 15 (9.6%) subjects had anti-Toxoplasma IgM antibodies. Male Tepehuanos aged 31-50 years showed a significantly higher frequency of exposure to T. gondii than female Tepehuanos of the same age. Seroprevalence of anti-T. gondii IgM antibodies was significantly higher in Tepehuanos without education than those with 7-12 years of education. Tepehuanos suffering from frequent headaches had significantly higher seroprevalences of anti-T. gondii IgG and IgM antibodies than those without this clinical feature. In addition, Tepehuanos suffering from hearing impairment had significantly higher seroprevalence of anti-T. gondii IgM antibodies than those without this clinical feature. Logistic regression analysis did not show an association of T. gondii exposure with any behavioral characteristics, including contact with cats or eating habits. The seroprevalence of T. gondii exposure in Tepehuanos is comparable to that reported in other populations in North America; however, seroprevalence in the largely rural Tepehuanos is higher than that reported in a nearby urban center. Toxoplasma may be impacting the health of Tepehuanos. This is the first report of T. gondii infection in Tepehuanos, and the results should prove useful for the design of preventive measures.

Interrelations between the Parasitophorous Vacuole of Toxoplasma gondii and Host Cell Organelles

NASA Astrophysics Data System (ADS)

Cardoso Magno, Rodrigo; Cobra Straker, Lorian; de Souza, Wanderley; Attias, Marcia

2005-04-01

Toxoplasma gondii, the causative agent of toxoplasmosis, is capable of actively penetrating and multiplying in any nucleated cell of warm-blooded animals. Its survival strategies include escape from fusion of the parasitophorous vacuole with host cell lysosomes and rearrangement of host cell organelles in relation to the parasitophorous vacuole. In this article we report the rearrangement of host cell organelles and elements of the cytoskeleton of LLCMK2 cells, a lineage derived from green monkey kidney epithelial cells, in response to infection by T. gondii tachyzoites. Transmission electron microscopy made on flat embedded monolayers cut horizontally to the apical side of the cells or field emission scanning electron microscopy of monolayers scraped with scotch tape before sputtering showed that association of mitochondria to the vacuole is much less frequent than previously described. On the other hand, all parasitophorous vacuoles were surrounded by elements of the endoplasmic reticulum. These data were complemented by observations by laser scanning microscopy using fluorescent probes from mitochondria and endoplasmic reticulum and reinforced by three-dimensional reconstruction from serial sections observed by transmission electron microscopy and labeling of mitochondria and endoplasmic reticulum by fluorescent probes.

Seroprevalence of Toxoplasma gondii in cats from Colombo, Sri Lanka

USDA-ARS?s Scientific Manuscript database

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...

Experimental reinfection of BALB/c mice with different recombinant type I/III strains of Toxoplasma gondii: involvement of IFN-gamma and IL-10.

PubMed

Brandão, Geane Peroni; Melo, Maria Norma; Gazzinelli, Ricardo Tostes; Caetano, Braulia Costa; Ferreira, Adriana Melo; Silva, Letícia Azevedo; Vitor, Ricardo Wagner Almeida

2009-03-01

To assess reinfection of BALB/c mice with different Toxoplasma gondii strains, the animals were prime infected with the non-virulent D8 strain and challenged with virulent recombinant strains. Thirty days after challenge, brain cysts were obtained from surviving BALB/c mice and inoculated in Swiss mice to obtain tachyzoites for DNA extraction and PCR-RFLP analysis to distinguish the different T. gondii strains present in possible co-infections. Anti-Toxoplasma immune responses were evaluated in D8-primed BALB/c mice by detecting IFN-gamma and IL-10 produced by T cells and measuring immunoglobulin levels in serum samples. PCR-RFLP demonstrated that BALB/c mice were reinfected with the EGS strain at 45 days post prime infection (dpi) and with the EGS and CH3 strains at 180 dpi. High levels of IFN-gamma were detected after D8 infection, with no significant difference between 45 and 180-day intervals. However, higher IL-10 levels and higher plasmatic IgG1 and IgA were detected from samples obtained 180 days after infection. BALB/c mice were susceptible to reinfection with different recombinant T. gondii strains and this susceptibility correlated with enhancement of IL-10 production.

Interleukin-22-deficiency and microbiota contribute to the exacerbation of Toxoplasma gondii-induced intestinal inflammation.

PubMed

Couturier-Maillard, A; Froux, N; Piotet-Morin, J; Michaudel, C; Brault, L; Le Bérichel, J; Sénéchal, A; Robinet, P; Chenuet, P; Jejou, S; Dumoutier, L; Renauld, J C; Iovanna, J; Huber, S; Quesniaux, Vfj; Sokol, H; Ryffel, B

2018-05-04

Upon oral infection with Toxoplasma gondii cysts (76 K strain) tachyzoites are released into the intestinal lumen and cross the epithelial barrier causing damage and acute intestinal inflammation in C57BL/6 (B6) mice. Here we investigated the role of microbiota and IL-22 in T.gondii-induced small intestinal inflammation. Oral T.gondii infection in B6 mice causes inflammation with IFNγ and IL-22 production. In IL-22-deficient mice, T.gondii infection augments the Th1 driven inflammation. Deficiency in either IL-22bp, the soluble IL-22 receptor or Reg3γ, an IL-22-dependent antimicrobial lectin/peptide, did not reduce inflammation. Under germ-free conditions, T.gondii-induced inflammation was reduced in correlation with parasite load. But intestinal inflammation is still present in germ-free mice, at low level, in the lamina propria, independently of IL-22 expression. Exacerbated intestinal inflammation driven by absence of IL-22 appears to be independent of IL-22 deficiency associated-dysbiosis as similar inflammation was observed after fecal transplantation of IL-22 -/- or WT microbiota to germ-free-WT mice. Our results suggest cooperation between parasite and intestinal microbiota in small intestine inflammation development and endogenous IL-22 seems to exert a protective role independently of its effect on the microbiota. In conclusion, IL-22 participates in T.gondii induced acute small intestinal inflammation independently of microbiota and Reg3γ.

A protein extract and a cysteine protease inhibitor enriched fraction from Jatropha curcas seed cake have in vitro anti-Toxoplasma gondii activity.

PubMed

Soares, A M S; Carvalho, L P; Melo, E J T; Costa, H P S; Vasconcelos, I M; Oliveira, J T A

2015-06-01

Toxoplasma gondii is a parasite of great medical and veterinary importance that has worldwide distribution and causes toxoplasmosis. There are few treatments available for toxoplasmosis and the search for plant extracts and compounds with anti-Toxoplasma activity is of utmost importance for the discovery of new active drugs. The objective of this study was to investigate the action of a protein extract and a protease inhibitor enriched fraction from J. curcas seed cake on developing tachyzoites of T. gondii-infected Vero cells. The protein extract (JcCE) was obtained after solubilization of the J. curcas seed cake with 100 mM sodium borate buffer, pH 10, centrifugation and dialysis of the resulting supernatant with the extracting buffer. JcCE was used for the in vitro assays of anti-Toxoplasma activity at 0.01, 0.1, 0.5, 1.5, 3.0 and 5.0 mg/ml concentration for 24 h. The results showed that JcCE reduced the percentage of infection and the number of intracellular parasites, but had no effect on the morphology of Vero cells up to 3.0 mg/mL. The cysteine protease inhibitor enriched fraction, which was obtained after chromatography of JcCE on Sephadex G-75 and presented a unique protein band following SDS-PAGE, reduced both the number of T. gondii infected cells and intracellular parasites. These results suggest that both JcCE and the cysteine protease inhibitor enriched fraction interfere with the intracellular growth of T. gondii. Copyright © 2015 Elsevier Inc. All rights reserved.

Targeted Phenotypic Screening in Plasmodium falciparum and Toxoplasma gondii Reveals Novel Modes of Action of Medicines for Malaria Venture Malaria Box Molecules

PubMed Central

2018-01-01

ABSTRACT The Malaria Box collection includes 400 chemically diverse small molecules with documented potency against malaria parasite growth, but the underlying modes of action are largely unknown. Using complementary phenotypic screens against Plasmodium falciparum and Toxoplasma gondii, we report phenotype-specific hits based on inhibition of overall parasite growth, apicoplast segregation, and egress or host invasion, providing hitherto unavailable insights into the possible mechanisms affected. First, the Malaria Box library was screened against tachyzoite stage T. gondii and the half-maximal effective concentrations (EC50s) of molecules showing ≥80% growth inhibition at 10 µM were determined. Comparison of the EC50s for T. gondii and P. falciparum identified a subset of 24 molecules with nanomolar potency against both parasites. Thirty molecules that failed to induce acute growth inhibition in T. gondii tachyzoites in a 2-day assay caused delayed parasite death upon extended exposure, with at least three molecules interfering with apicoplast segregation during daughter cell formation. Using flow cytometry and microscopy-based examinations, we prioritized 26 molecules with the potential to inhibit host cell egress/invasion during asexual developmental stages of P. falciparum. None of the inhibitors affected digestive vacuole integrity, ruling out a mechanism mediated by broadly specific protease inhibitor activity. Interestingly, five of the plasmodial egress inhibitors inhibited ionophore-induced egress of T. gondii tachyzoites. These findings highlight the advantage of comparative and targeted phenotypic screens in related species as a means to identify lead molecules with a conserved mode of action. Further work on target identification and mechanism analysis will facilitate the development of antiparasitic compounds with cross-species efficacy. IMPORTANCE The phylum Apicomplexa includes many human and animal pathogens, such as Plasmodium falciparum

Antibody Detection and Molecular Characterization of Toxoplasma gondii from Bobcats (Lynx rufus), Domestic Cats (Felis catus), and Wildlife from Minnesota, USA.

PubMed

Verma, Shiv K; Minicucci, Larissa; Murphy, Darby; Carstensen, Michelle; Humpal, Carolin; Wolf, Paul; Calero-Bernal, Rafael; Cerqueira-Cézar, Camila K; Kwok, Oliver C H; Su, Chunlei; Hill, Dolores; Dubey, Jitender P

2016-09-01

Little is known of the epidemiology of toxoplasmosis in Minnesota. Here, we evaluated Toxoplasma gondii infection in 50 wild bobcats (Lynx rufus) and 75 other animals on/near 10 cattle farms. Antibodies to T. gondii were assayed in serum samples or tissue fluids by the modified agglutination test (MAT, cut-off 1:25). Twenty nine of 50 bobcats and 15 of 41 wildlife trapped on the vicinity of 10 farms and nine of 16 adult domestic cats (Felis catus) and six of 14 domestic dogs resident on farms were seropositive. Toxoplasma gondii oocysts were not found in feces of any felid. Tissues of all seropositive wild animals trapped on the farm were bioassayed in mice and viable T. gondii was isolated from two badgers (Taxidea taxus), two raccoons (Procyon lotor), one coyote (Canis latrans), and one opossum (Didelphis virginiana). All six T. gondii isolates were further propagated in cell culture. Multi-locus PCR-RFLP genotyping using 10 markers (SAG1, SAG2 (5'-3'SAG2, and alt.SAG2), SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico), and DNA from cell culture derived tachyzoites revealed three genotypes; #5 ToxoDataBase (1 coyote, 1 raccoon), #1 (1 badger, 1 raccoon, 1 opossum), and #2 (1 badger). This is the first report of T. gondii prevalence in domestic cats and in bobcats from Minnesota, and the first isolation of viable T. gondii from badger. Published 2016. This article is a U.S. Government work and is in the public domain in the USA.

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

NASA Astrophysics Data System (ADS)

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

2011-05-01

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

Ciprofloxacin Derivatives Affect Parasite Cell Division and Increase the Survival of Mice Infected with Toxoplasma gondii

PubMed Central

Martins-Duarte, Erica S.; Dubar, Faustine; Lawton, Philippe; França da Silva, Cristiane; C. Soeiro, Maria de Nazaré; de Souza, Wanderley; Biot, Christophe; Vommaro, Rossiane C.

2015-01-01

Toxoplasmosis, caused by the protozoan Toxoplasma gondii, is a worldwide disease whose clinical manifestations include encephalitis and congenital malformations in newborns. Previously, we described the synthesis of new ethyl-ester derivatives of the antibiotic ciprofloxacin with ~40-fold increased activity against T. gondii in vitro, compared with the original compound. Cipro derivatives are expected to target the parasite’s DNA gyrase complex in the apicoplast. The activity of these compounds in vivo, as well as their mode of action, remained thus far uncharacterized. Here, we examined the activity of the Cipro derivatives in vivo, in a model of acute murine toxoplasmosis. In addition, we investigated the cellular effects T. gondii tachyzoites in vitro, by immunofluorescence and transmission electron microscopy (TEM). When compared with Cipro treatment, 7-day treatments with Cipro derivatives increased mouse survival significantly, with 13–25% of mice surviving for up to 60 days post-infection (vs. complete lethality 10 days post-infection, with Cipro treatment). Light microscopy examination early (6 and 24h) post-infection revealed that 6-h treatments with Cipro derivatives inhibited the initial event of parasite cell division inside host cells, in an irreversible manner. By TEM and immunofluorescence, the main cellular effects observed after treatment with Cipro derivatives and Cipro were cell scission inhibition - with the appearance of ‘tethered’ parasites – malformation of the inner membrane complex, and apicoplast enlargement and missegregation. Interestingly, tethered daughter cells resulting from Cipro derivatives, and also Cipro, treatment did not show MORN1 cap or centrocone localization. The biological activity of Cipro derivatives against C. parvum, an apicomplexan species that lacks the apicoplast, is, approximately, 50 fold lower than that in T. gondii tachyzoites, supporting that these compounds targets the apicoplast. Our results show

Enrofloxacin and Toltrazuril Are Able to Reduce Toxoplasma gondii Growth in Human BeWo Trophoblastic Cells and Villous Explants from Human Third Trimester Pregnancy

PubMed Central

da Silva, Rafaela J.; Gomes, Angelica O.; Franco, Priscila S.; Pereira, Ariane S.; Milian, Iliana C. B.; Ribeiro, Mayara; Fiorenzani, Paolo; dos Santos, Maria C.; Mineo, José R.; da Silva, Neide M.; Ferro, Eloisa A. V.; de Freitas Barbosa, Bellisa

2017-01-01

Classical treatment for congenital toxoplasmosis is based on combination of sulfadiazine and pyrimethamine plus folinic acid. Due to teratogenic effects and bone marrow suppression caused by pyrimethamine, the establishment of new therapeutic strategies is indispensable to minimize the side effects and improve the control of infection. Previous studies demonstrated that enrofloxacin and toltrazuril reduced the incidence of Neospora caninum and Toxoplasma gondii infection. The aim of the present study was to evaluate the efficacy of enrofloxacin and toltrazuril in the control of T. gondii infection in human trophoblast cells (BeWo line) and in human villous explants from the third trimester. BeWo cells and villous were treated with several concentrations of enrofloxacin, toltrazuril, sulfadiazine, pyrimethamine, or combination of sulfadiazine+pyrimethamine, and the cellular or tissue viability was verified. Next, BeWo cells were infected by T. gondii (2F1 clone or the ME49 strain), whereas villous samples were only infected by the 2F1 clone. Then, infected cells and villous were treated with all antibiotics and the T. gondii intracellular proliferation as well as the cytokine production were analyzed. Finally, we evaluated the direct effect of enrofloxacin and toltrazuril in tachyzoites to verify possible changes in parasite structure. Enrofloxacin and toltrazuril did not decrease the viability of cells and villous in lower concentrations. Both drugs were able to significantly reduce the parasite intracellular proliferation in BeWo cells and villous explants when compared to untreated conditions. Regardless of the T. gondii strain, BeWo cells infected and treated with enrofloxacin or toltrazuril induced high levels of IL-6 and MIF. In villous explants, enrofloxacin induced high MIF production. Finally, the drugs increased the number of unviable parasites and triggered damage to tachyzoite structure. Taken together, it can be concluded that enrofloxacin and

Enrofloxacin and Toltrazuril Are Able to Reduce Toxoplasma gondii Growth in Human BeWo Trophoblastic Cells and Villous Explants from Human Third Trimester Pregnancy.

PubMed

da Silva, Rafaela J; Gomes, Angelica O; Franco, Priscila S; Pereira, Ariane S; Milian, Iliana C B; Ribeiro, Mayara; Fiorenzani, Paolo; Dos Santos, Maria C; Mineo, José R; da Silva, Neide M; Ferro, Eloisa A V; de Freitas Barbosa, Bellisa

2017-01-01

Classical treatment for congenital toxoplasmosis is based on combination of sulfadiazine and pyrimethamine plus folinic acid. Due to teratogenic effects and bone marrow suppression caused by pyrimethamine, the establishment of new therapeutic strategies is indispensable to minimize the side effects and improve the control of infection. Previous studies demonstrated that enrofloxacin and toltrazuril reduced the incidence of Neospora caninum and Toxoplasma gondii infection. The aim of the present study was to evaluate the efficacy of enrofloxacin and toltrazuril in the control of T. gondii infection in human trophoblast cells (BeWo line) and in human villous explants from the third trimester. BeWo cells and villous were treated with several concentrations of enrofloxacin, toltrazuril, sulfadiazine, pyrimethamine, or combination of sulfadiazine+pyrimethamine, and the cellular or tissue viability was verified. Next, BeWo cells were infected by T. gondii (2F1 clone or the ME49 strain), whereas villous samples were only infected by the 2F1 clone. Then, infected cells and villous were treated with all antibiotics and the T. gondii intracellular proliferation as well as the cytokine production were analyzed. Finally, we evaluated the direct effect of enrofloxacin and toltrazuril in tachyzoites to verify possible changes in parasite structure. Enrofloxacin and toltrazuril did not decrease the viability of cells and villous in lower concentrations. Both drugs were able to significantly reduce the parasite intracellular proliferation in BeWo cells and villous explants when compared to untreated conditions. Regardless of the T. gondii strain, BeWo cells infected and treated with enrofloxacin or toltrazuril induced high levels of IL-6 and MIF. In villous explants, enrofloxacin induced high MIF production. Finally, the drugs increased the number of unviable parasites and triggered damage to tachyzoite structure. Taken together, it can be concluded that enrofloxacin and

Calcium Signaling throughout the Toxoplasma gondii Lytic Cycle

PubMed Central

Borges-Pereira, Lucas; Budu, Alexandre; McKnight, Ciara A.; Moore, Christina A.; Vella, Stephen A.; Hortua Triana, Miryam A.; Liu, Jing; Garcia, Celia R. S.; Pace, Douglas A.; Moreno, Silvia N. J.

2015-01-01

Toxoplasma gondii is an obligate intracellular parasite that invades host cells, creating a parasitophorous vacuole where it communicates with the host cell cytosol through the parasitophorous vacuole membrane. The lytic cycle of the parasite starts with its exit from the host cell followed by gliding motility, conoid extrusion, attachment, and invasion of another host cell. Here, we report that Ca2+ oscillations occur in the cytosol of the parasite during egress, gliding, and invasion, which are critical steps of the lytic cycle. Extracellular Ca2+ enhances each one of these processes. We used tachyzoite clonal lines expressing genetically encoded calcium indicators combined with host cells expressing transiently expressed calcium indicators of different colors, and we measured Ca2+ changes in both parasites and host simultaneously during egress. We demonstrated a link between cytosolic Ca2+ oscillations in the host and in the parasite. Our approach also allowed us to measure two new features of motile parasites, which were enhanced by Ca2+ influx. This is the first study showing, in real time, Ca2+ signals preceding egress and their direct link with motility, an essential virulence trait. PMID:26374900

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.

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.

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

DOE PAGES

Ruan, Jiapeng; Mouveaux, Thomas; Light, Samuel H.; ...

2015-03-01

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

Toxoplasma lymphadenitis diagnosed by fine-needle aspiration cytology: a rare finding.

PubMed

Hosokawa, S; Kusama, Y; Ono, T; Mineta, H

2014-06-01

There are only very few reports of cervical toxoplasma lymphadenitis being diagnosed exclusively via fine-needle aspiration cytology (with serology). We describe a case of toxoplasma lymphadenitis that was successfully diagnosed by fine-needle aspiration cytology. The case involved a male patient who was immunocompromised as a result of recurrent acute myelogenous leukaemia with cervical lymphadenopathy. The biopsy showed typical features of a well-defined pseudocyst containing Toxoplasma gondii tachyzoites. Toxoplasma lymphadenitis is a common cause of lymph node enlargement. Fine-needle aspiration cytology is a useful method for diagnosing and differentiating toxoplasma lymphadenitis from more serious causes of lymphadenopathy, such as metastatic lymphadenopathy or lymphoma.

IDENTIFICATION OF A SPOROZOITE-SPECIFIC ANTIGEN FROM TOXOPLASMA GONDII

PubMed Central

Hill, Dolores; Coss, Cathleen; Dubey, J. P.; Wroblewski, Kristen; Sautter, Mari; Hosten, Tiffany; Muñoz-Zanzi, Claudia; Mui, Ernest; Withers, Shawn; Boyer, Kenneth; Hermes, Gretchen; Coyne, Jessica; Jagdis, Frank; Burnett, Andrew; McLeod, Patrick; Morton, Holmes; Robinson, Donna; McLeod, Rima

2013-01-01

Reduction of risk of human and food animal infection with Toxoplasma gondii is hampered by the lack of epidemiological data documenting the predominant routes of infection (oocyst versus tissue cyst consumption) in horizontally transmitted toxoplasmosis. Existing serological assays can determine previous exposure to the parasite, but not the route of infection. We have used difference gel electrophoresis in combination with tandem mass spectroscopy and Western blot to identify a sporozoite-specific protein (Toxoplasma gondii embryogenesis-related protein, TgERP) which elicited antibody and differentiated oocyst- versus tissue cyst-induced infection in pigs and mice. The recombinant protein was selected from a cDNA library constructed from T. gondii sporozoites, and this protein was used in Western blots and probed with sera from T. gondii infected humans. Serum antibody to TgERP was detected in humans within 6–8 mo of initial oocyst-acquired infection. Of 163 individuals in the acute stage of infection (anti-Toxoplasma IgM detected in sera, or <30 in the IgG avidity test), 103 (63.2%) had detectable antibodies that reacted with TgERP. Of 176 individuals with unknown infection route and in the chronic stage of infection (no anti-Toxoplasma IgM detected in sera, or >30 in the IgG avidity test), antibody to TgERP was detected in 31 (17.6%). None of the 132 uninfected individuals tested had detectable antibody to TgERP. These data suggest that TgERP may be useful in detecting exposure to sporozoites in early Toxoplasma infection and implicates oocysts as the agent of infection. PMID:21506817

21 CFR 866.3780 - Toxoplasma gondii serological reagents.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Toxoplasma gondii serological reagents. 866.3780 Section 866.3780 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3780 Toxoplasma...

21 CFR 866.3780 - Toxoplasma gondii serological reagents.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Toxoplasma gondii serological reagents. 866.3780 Section 866.3780 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3780 Toxoplasma...

21 CFR 866.3780 - Toxoplasma gondii serological reagents.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Toxoplasma gondii serological reagents. 866.3780 Section 866.3780 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3780 Toxoplasma...

21 CFR 866.3780 - Toxoplasma gondii serological reagents.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Toxoplasma gondii serological reagents. 866.3780 Section 866.3780 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3780 Toxoplasma...

21 CFR 866.3780 - Toxoplasma gondii serological reagents.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Toxoplasma gondii serological reagents. 866.3780 Section 866.3780 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3780 Toxoplasma...

Neutrophil Depletion during Toxoplasma gondii Infection Leads to Impaired Immunity and Lethal Systemic Pathology

PubMed Central

Bliss, Susan K.; Gavrilescu, L. Cristina; Alcaraz, Ana; Denkers, Eric Y.

2001-01-01

The immunomodulatory role of neutrophils during infection with Toxoplasma gondii was investigated. Monoclonal antibody-mediated depletion revealed that neutrophils are essential for survival during the first few days of infection. Moreover, neutrophil depletion was associated with a weaker type 1 immune response as measured by decreased levels of gamma interferon, interleukin-12 (IL-12) and tumor necrosis factor alpha. IL-10 was also decreased in depleted animals. Additionally, splenic populations of CD4+ T cells, CD8+ T cells, and NK1.1+ cells were decreased in depleted mice. Neutrophil-depleted mice exhibited lesions of greater severity in tissues examined and a greater parasite burden as determined by histopathology and reverse transcription-PCR. We conclude that neutrophils are critical near the time of infection because they influence the character of the immune response and control tachyzoite replication. PMID:11447166

Detection of Toxoplasma gondii DNA in the milk of naturally infected ewes.

PubMed

Camossi, L G; Greca-Júnior, H; Corrêa, A P F L; Richini-Pereira, V B; Silva, R C; Da Silva, A V; Langoni, H

2011-05-11

Toxoplasmosis is the major parasitic disease affecting sheep. It is important for veterinary medicine, animal science and public health since it causes reproductive and economic losses in the herd, as well as damaging human health due to consumption of contaminated meat and milk, which can facilitate zoonotic transmission. Detection of Toxoplasma gondii in ovine milk and lack of data in the literature describing differentiation between acute and chronic disease for this species stimulated the elaboration of the present research project. To achieve the aim of this study, the animals were allocated to two groups of 20 ewes each, of which group 1 was composed of animals with positive serology and group 2 with negative serology. Acute and chronic stages of the disease were differentiated by modified direct agglutination test (MAT), in which antigens were fixed with formalin (MAT-AF) and methanol (MAT-AM). The parasite was detected in milk by polymerase chain reaction (PCR), and the molecular identity of the amplified products was confirmed by sequencing. The serological results indicated that sheep had a chronic infection profile. T. gondii DNA was detected in seven milk samples from five seropositive sheep, and twice in milk of two sheep. Sequences of species shared 97-100% identity with T. gondii. These findings allowed the hypothesis that the peripartum period may also lead to the resurgence of tissue T. gondii tachyzoites cysts which can circulate again and be excreted in the milk. This study used sheep naturally infected with T. gondii as a prerequisite for further investigations on the possible participation of this species in toxoplasmosis epidemiology and as a potential transmission route related to consumption of milk from infected sheep. Copyright © 2010 Elsevier B.V. All rights reserved.

Molecular cloning and characterization of an SRCAP chromatin remodeling homologue in Toxoplasma gondii.

PubMed

Sullivan, William J; Monroy, M Alexandra; Bohne, Wolfgang; Nallani, Karuna C; Chrivia, John; Yaciuk, Peter; Smith, Charles K; Queener, Sherry F

2003-05-01

We have identified and mapped a gene in Toxoplasma gondii that encodes a homologue of SRCAP (Snf2-related CBP activator protein), a member of the SNF/SWI family of chromatin remodeling factors. The genomic locus (TgSRCAP) is present as a single copy and contains 16 introns. The predicted cDNA contains an open reading frame of 8,775 bp and encodes a protein of 2,924 amino acids. We have identified additional SRCAP-like sequences in Apicomplexa for comparison by screening genomic databases. An analysis of SRCAP homologues between species reveals signature features that may be indicative of SRCAP members. Expression of mRNA encoding TgSRCAP is upregulated when tachyzoite (invasive form) parasites are induced to differentiate into bradyzoites (encysted form) in vitro. Recombinant TgSRCAP protein is functionally equivalent to the human homologue, being capable of increasing transcription mediated by CREB.

GENETIC DIVERSITY OF TOXOPLASMA GONDII ISOLATES FROM CHICKENS FROM BRAZIL

USDA-ARS?s Scientific Manuscript database

Until recently, Toxoplasma gondii was considered clonal with very little genetic variability. Recent studies indicate that T. gondii isolates from Brazil are genetically and biologically different from T. gondii isolates from USA and Europe. In the present study, we retyped 151 free range chicken is...

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ruan, Jiapeng; Mouveaux, Thomas; Light, Samuel H.

2015-03-01

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

Intraocular cysts of toxoplasma gondii in patients with necrotizing retinitis following periocular/intraocular triamcinolone injection.

PubMed

Nijhawan, Raje; Bansal, Reema; Gupta, Nalini; Beke, Nikhil; Kulkarni, Pandurang; Gupta, Amod

2013-10-01

To report the detection of Toxoplasma gondii cysts in intraocular aspirates of patients with necrotizing retinitis following periocular/intraocular corticosteroid injection. Case report. Two patients (2 eyes) with widespread necrotizing retinitis in a steroid-exposed eye posed a diagnostic challenge and underwent pars plana vitrectomy (PPV). Intraocular samples (vitreous fluid, retinal tissue, and subretinal aspirate in case 1, and vitreous fluid in case 2) were subjected to cytological examination. The subretinal aspirate (case 1) revealed encysted bradyzoites of Toxoplasma gondii. Vitreous fluid (case 2) tested positive for anti-toxoplasma antibodies and the smear showed encysted forms of Toxoplasma gondii on cytology. CONCLUSION. Toxoplasma gondii cysts were detected in eyes with necrotizing retinitis that developed secondary to injudicious use of corticosteroids.

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).

Pravastatin and simvastatin inhibit the adhesion, replication and proliferation of Toxoplasma gondii (RH strain) in HeLa cells.

PubMed

Sanfelice, Raquel Arruda; da Silva, Suelen Santos; Bosqui, Larissa Rodrigues; Miranda-Sapla, Milena Menegazzo; Barbosa, Bellisa Freitas; Silva, Rafaela José; Ferro, Eloísa A Vieira; Panagio, Luciano Aparecido; Navarro, Italmar Teodorico; Bordignon, Juliano; Conchon-Costa, Ivete; Pavanelli, Wander Rogerio; Almeida, Ricardo Sergio; Costa, Idessania Nazareth

2017-03-01

The conventional treatment for toxoplasmosis with pyrimethamine and sulfadiazine shows toxic effects to the host, and it is therefore necessary to search for new drugs. Some studies suggest the use of statins, which inhibit cholesterol synthesis in humans and also the initial processes of isoprenoid biosynthesis in the parasite. Thus, the objective of this study was to evaluate the activity of the statins pravastatin and simvastatin in HeLa cells infected in vitro with the RH strain of T. gondii. HeLa cells (1×10 5 ) were infected with T. gondii tachyzoites (5×10 5 ) following two different treatment protocols. In the first protocol, T. gondii tachyzoites were pretreated with pravastatin (50 and 100μg/mL) and simvastatin (1.56 and 3.125μg/mL) for 30min prior to infection. In the second, HeLa cells were first infected (5×10 5 ) with tachyzoites and subsequently treated with pravastatin and simvastatin for 24h at the concentrations noted above. Initially, we evaluated the cytotoxicity of drugs by the MTT assay, number of tachyzoites adhered to cells, number of infected cells, and viability of tachyzoites by trypan blue exclusion. The supernatant of the cell cultures was collected post-treatment for determination of the pattern of Th1/Th2/Th17 cytokines by cytometric bead array. There was no cytotoxicity to HeLa cells with 50 and 100μg/mL pravastatin and 1.56 and 3.125μg/mL simvastatin. There was no change in the viability of tachyzoites that received pretreatment. Regarding the pre- and post-treatment of the cells with pravastatin and simvastatin alone, there was a reduction in adhesion, invasion and proliferation of cells to T. gondii. As for the production of cytokines, we found that IL-6 and IL-17 were significantly reduced in cells infected with T. gondii and treated with pravastatin and simvastatin, when compared to control. Based on these results, we can infer that pravastatin and simvastatin alone possess antiproliferative effects on tachyzoites forms

Disseminated toxoplasmosis Toxoplasma gondii in a wild Florida manatee Trichechus manatus latirostris and seroprevalence in two wild populations.

PubMed

Smith, Lauren N; Waltzek, Thomas B; Rotstein, David S; Francis-Floyd, Ruth; Walsh, Michael T; Wellehan, James F X; Gerhold, Rick; Chapman, Alycia E; de Wit, Martine

2016-11-22

Marine mammals are important indicators for ecosystem health and serve as sentinel species for infectious agents including zoonoses. Histological examination of tissues from a stranded Florida manatee Trichechus manatus latirostris revealed protozoal cysts in the cerebrum and intrahistiocytic tachyzoites in the liver and caudal mesenteric lymph node. Disseminated Toxoplasma gondii infection was confirmed by immunohistochemistry and sequencing of the nuclear ribosomal internal transcribed spacer region of formalin-fixed tissues. The lack of baseline information on Florida manatees' exposure to this pathogen prompted a study into the seroprevalence of T. gondii in 2 separate geographic habitats in Florida, USA, during the winters from 2011-2014. Serum was collected during routine health assessments of 44 apparently healthy manatees from Crystal River (n = 26) on the west central coast of Florida and Brevard County (n = 18) on the east coast of Florida. Serum was screened for detection of T. gondii immunoglobulin G (IgG) antibodies via the modified agglutination test. Two animals from Crystal River from 2011 and 2012 (7.7%) and one animal from Brevard County from 2011 (5.6%) tested positive for T. gondii antibodies. Overall seroprevalence for T. gondii was low in the 2 sampled populations and may reflect a low seroprevalence or animal susceptibility. However, continued monitoring of this pathogen in aquatic ecosystems is warranted due to both possible anthropogenic sources and zoonotic potential.

Modification of growth rate of Toxoplasma gondii by continuous passage in immune mice.

PubMed

Yano, K; Nakabayashi, T; Inoki, S

1987-05-01

Growth of the RH strain of Toxoplasma gondii, is suppressed in mice immunized with Toxoplasma antigens. At the second passage, the growth of T. gondii harvested from immune mice is suppressed more strongly in immune mice than that of T. gondii from control mice. After 52 passages in immune mice, the growth of T. gondii was still suppressed in immune mice than in control mice. T. gondii did not possess ability of antigenic variation (Pfefferkorn et al., 1983). After vaccination with the S-273 strain of T. gondii, mice were challenged twice with the RH strain. Cysts in brains caused death of all mice by inoculation at the 1st, 2nd, 3rd, 4th and 8th week after the second challenge of the RH strain. But the cysts from mice at the 16th and 30th week have decreased virulence, causing death in only 2 out of 4 and 1 out of 4 mice, respectively. Virulence of cysts had no definite relationship to Toxoplasma antibodies by indirect latex agglutination test and the numbers of cysts per brain. Growth variation of T. gondii is proposed under unfavourable conditions as in mice immunized with Toxoplasma antigens or vaccinated with the S-273 strain.

Identification of a sporozoite-specific antigen from Toxoplasma gondii

USDA-ARS?s Scientific Manuscript database

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...

Mast cell activator compound 48/40 is not an effective adjuvant for UV-attenuated Toxoplasma gondii vaccine.

PubMed

Li, Xi; Chen, Shengjie; Huang, Shiguang; Lu, Fangli

2017-08-01

Toxoplasma gondii (T. gondii, Tg) is a globally distributed parasitic protozoan causing different forms of toxoplasmosis in humans. Mast cells (MCs) play a role during T. gondii infection. Several studies suggest that MC activator compound 48/80 (C48/80) may be an effective vaccine adjuvant resulting in a potent and protective antigen-specific immune response against bacteria or virus infections. The present study was performed to determine whether C48/80 had adjuvant activity for ultraviolet (UV)-attenuated T. gondii vaccine to induce protective immune responses against T. gondii in mouse model. Kunming mice were divided into the following groups: naive mice, naive mice administrated with C48/80 intraperitoneal (i.p.) injection, mice infected by i.p. injection of 10 4 T. gondii RH strain alone (Tg group), mice infected with 10 4 RH tachyzoites plus C48/80 administration (Tg + C48/80), mice immunized with UV-Tg alone, and mice immunized with UV-Tg plus C48/80 administration (UV-Tg + C48/80). All the vaccinated mice were challenged with 10 4 tachyzoites of T. gondii RH strain at the same time as the primary infection. The survival rates, liver histopathologies, liver parasite burdens, and mRNA expression levels of Th1 and Th2 cytokines in the livers and spleens detected by quantitative real-time reverse transcription-polymerase chain reaction (qRT-PCR) were compared among the aforementioned groups after primary infection or challenge infection. The results showed that, compared to the Tg group or Tg + C48/80 group, the UV-Tg + Tg group and UV-Tg + C48/80 + Tg group had significantly prolonged survival time, lower liver histopathological scores, decreased liver parasite burdens, and increased levels of Th1 and Th2 cytokines in the livers and spleens. There was no significant difference of survival time between the UV-Tg + Tg group and the UV-Tg + C48/80 + Tg group; however, the UV-Tg + C48/80 + Tg group showed higher parasite burden, more severe

Toxoplasma growth in vitro is dependent on exogenous tyrosine and is independent of AAH2 even in tyrosine-limiting conditions.

PubMed

Marino, Nicole D; Boothroyd, John C

2017-05-01

Toxoplasma gondii is an obligate intracellular parasite capable of infecting virtually all nucleated cell types in almost all warm-blooded animals. Interestingly, Toxoplasma has a relatively full repertoire of amino acid biosynthetic machinery, perhaps reflecting its broad host range and, consequently, its need to adapt to a wide array of amino acid resources. Although Toxoplasma has been shown to be auxotrophic for tryptophan and arginine, it has not previously been determined if Toxoplasma is also auxotrophic for tyrosine. Toxoplasma tachyzoites and bradyzoites were recently found to express an amino acid hydroxylase (AAH2) that is capable of synthesizing tyrosine and dihydroxyphenylalanine (DOPA) from phenylalanine; however, the role of AAH2 in tachyzoite and bradyzoite infection has not yet been identified. To determine if Toxoplasma requires exogenous tyrosine for growth, we performed growth assays on tachyzoites and bradyzoites in nutrient-rich media titrated with varying amounts of tyrosine. We found that Toxoplasma tachyzoites form significantly smaller plaques in tyrosine-limiting media in a dose-dependent manner and that this phenotype is not affected by deletion of TgAAH2. To determine if bradyzoites require exogenous tyrosine for growth, we induced differentiation from tachyzoites in vitro in tyrosine-limiting media and found that replication and vacuole number are all decreased in tyrosine-deficient media. Importantly, culture of confluent human fibroblasts in tyrosine-deficient media does not affect their viability, indicating that, at least in vitro, the need for tyrosine is at the level of Toxoplasma, not the host cell supporting its growth. Copyright © 2017 Elsevier Inc. All rights reserved.

In Vitro Effect of the Synthetic cal14.1a Conotoxin, Derived from Conus californicus, on the Human Parasite Toxoplasma gondii

PubMed Central

De León-Nava, Marco A.; Romero-Núñez, Eunice; Luna-Nophal, Angélica; Bernáldez-Sarabia, Johanna; Sánchez-Campos, Liliana N.; Licea-Navarro, Alexei F.; Morales-Montor, Jorge; Muñiz-Hernández, Saé

2016-01-01

Toxins that are secreted by cone snails are small peptides that are used to treat several diseases. However, their effects on parasites with human and veterinary significance are unknown. Toxoplasma gondii is an opportunistic parasite that affects approximately 30% of the world’s population and can be lethal in immunologically compromised individuals. The conventional treatment for this parasitic infection has remained the same since the 1950s, and its efficacy is limited to the acute phase of infection. These findings have necessitated the search for new drugs that specifically target T. gondii. We examined the effects of the synthetic toxin cal14.1a (s-cal14.1a) from C. californicus on the tachyzoite form of T. gondii. Our results indicate that, at micromolar concentrations, s-cal14.1a lowers viability and inhibits host cell invasion (by 50% and 61%, respectively) on exposure to extracellular parasites. Further, intracellular replication decreased significantly while viability of the host cell was unaffected. Our study is the first report on the antiparasitic activity of a synthetic toxin of C. californicus. PMID:27070627

In Vitro Effect of the Synthetic cal14.1a Conotoxin, Derived from Conus californicus, on the Human Parasite Toxoplasma gondii.

PubMed

De León-Nava, Marco A; Romero-Núñez, Eunice; Luna-Nophal, Angélica; Bernáldez-Sarabia, Johanna; Sánchez-Campos, Liliana N; Licea-Navarro, Alexei F; Morales-Montor, Jorge; Muñiz-Hernández, Saé

2016-04-08

Toxins that are secreted by cone snails are small peptides that are used to treat several diseases. However, their effects on parasites with human and veterinary significance are unknown. Toxoplasma gondii is an opportunistic parasite that affects approximately 30% of the world's population and can be lethal in immunologically compromised individuals. The conventional treatment for this parasitic infection has remained the same since the 1950s, and its efficacy is limited to the acute phase of infection. These findings have necessitated the search for new drugs that specifically target T. gondii. We examined the effects of the synthetic toxin cal14.1a (s-cal14.1a) from C. californicus on the tachyzoite form of T. gondii. Our results indicate that, at micromolar concentrations, s-cal14.1a lowers viability and inhibits host cell invasion (by 50% and 61%, respectively) on exposure to extracellular parasites. Further, intracellular replication decreased significantly while viability of the host cell was unaffected. Our study is the first report on the antiparasitic activity of a synthetic toxin of C. californicus.

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.

Loop-mediated isothermal amplification (LAMP): early detection of Toxoplasma gondii infection in mice.

PubMed

Kong, Qing-Ming; Lu, Shao-Hong; Tong, Qun-Bo; Lou, Di; Chen, Rui; Zheng, Bin; Kumagai, Takashi; Wen, Li-Yong; Ohta, Nobuo; Zhou, Xiao-Nong

2012-01-03

Toxoplasmosis is a widespread zoonotic parasitic disease that occurs in both animals and humans. Traditional molecular assays are often difficult to perform, especially for the early diagnosis of Toxoplasma gondii infections. Here, we established a novel loop-mediated isothermal amplification targeting the 529 bp repeat element (529 bp-LAMP) to detect T. gondii DNA in blood samples of experimental mice infected with tachyzoites of the RH strain. The assay was performed with Bst DNA polymerase at 65°C for 1 h. The detection limit of the 529 bp-LAMP assay was as low as 0.6 fg of T. gondii DNA. The sensitivity of this assay was 100 and 1000 fold higher than that of the LAMP targeting B1 gene (B1-LAMP) and nested PCR targeting 529 bp repeat element (529 bp-nested PCR), respectively. The specificity of the 529 bp-LAMP assay was determined using the DNA samples of Trypanosoma evansi, Plasmodium falciparum, Paragonimus westermani, Schistosoma japonicum, Fasciola hepatica and Angiostrongylus cantonensis. No cross-reactivity with the DNA of any parasites was found. The assay was able to detect T. gondii DNA in all mouse blood samples at one day post infection (dpi). We report the following findings: (i) The detection limit of the 529 bp-LAMP assay is 0.6 fg of T. gondii DNA; (ii) The assay does not involve any cross-reactivity with the DNA of other parasites; (iii) This is the first report on the application of the LAMP assay for early diagnosis of toxoplasmosis in blood samples from experimentally infected mice. Due to its simplicity, sensitivity and cost-effectiveness for common use, we suggest that this assay should be used as an early diagnostic tool for health control of toxoplasmosis.

Ablation of an Ovarian Tumor Family Deubiquitinase Exposes the Underlying Regulation Governing the Plasticity of Cell Cycle Progression in Toxoplasma gondii.

PubMed

Dhara, Animesh; de Paula Baptista, Rodrigo; Kissinger, Jessica C; Snow, E Charles; Sinai, Anthony P

2017-11-21

The Toxoplasma genome encodes the capacity for distinct architectures underlying cell cycle progression in a life cycle stage-dependent manner. Replication in intermediate hosts occurs by endodyogeny, whereas a hybrid of schizogony and endopolygeny occurs in the gut of the definitive feline host. Here, we characterize the consequence of the loss of a cell cycle-regulated o varian tu mor (OTU family) deubiquitinase, OTUD3A of Toxoplasma gondii (TgOTUD3A; TGGT1_258780), in T. gondii tachyzoites. Rather than the mutation being detrimental, mutant parasites exhibited a fitness advantage, outcompeting the wild type. This phenotype was due to roughly one-third of TgOTUD3A-knockout (TgOTUD3A-KO) tachyzoites exhibiting deviations from endodyogeny by employing replication strategies that produced 3, 4, or 5 viable progeny within a gravid mother instead of the usual 2. We established the mechanistic basis underlying these altered replication strategies to be a dysregulation of centrosome duplication, causing a transient loss of stoichiometry between the inner and outer cores that resulted in a failure to terminate S phase at the attainment of 2N ploidy and/or the decoupling of mitosis and cytokinesis. The resulting dysregulation manifested as deviations in the normal transitions from S phase to mitosis (S/M) (endopolygeny-like) or M phase to cytokinesis (M/C) (schizogony-like). Notably, these imbalances are corrected prior to cytokinesis, resulting in the generation of normal progeny. Our findings suggest that decisions regarding the utilization of specific cell cycle architectures are controlled by a ubiquitin-mediated mechanism that is dependent on the absolute threshold levels of an as-yet-unknown target(s). Analysis of the TgOTUD3A-KO mutant provides new insights into mechanisms underlying the plasticity of apicomplexan cell cycle architecture. IMPORTANCE Replication by Toxoplasma gondii can occur by 3 distinct cell cycle architectures. Endodyogeny is used by asexual

Anti-Toxoplasma gondii secretory IgA in tears of patients with ocular toxoplasmosis: immunodiagnostic validation by ELISA.

PubMed

Lynch, Maria Isabel; Malagueño, Elizabeth; Lynch, Luiz Felipe; Ferreira, Silvana; Stheling, Raphael; Oréfice, Fernando

2009-09-01

Toxoplasma gondii causes posterior uveitis and the specific diagnosis is based on clinical criteria. The presence of anti-T. gondii secretory IgA (sIgA) antibodies in patients' tears has been reported and an association was found between ocular toxoplasmosis and the anti-T. gondii sIgA isotype in Brazilian patients. The purpose of this study was to provide an objective validation of the published ELISA test for determining the presence of anti-T. gondii sIgA in the tears of individuals with ocular toxoplasmosis. Tears from 156 patients with active posterior uveitis were analysed; 82 of them presented characteristics of ocular toxoplasmosis (standard lesion) and 74 patients presented uveitis due to other aetiologies. Cases of active posterior uveitis were considered standard when a new inflammatory focus satellite to old retinochoroidal scars was observed. The determination of anti-T. gondii sIgA was made using an ELISA test with crude tachyzoite antigenic extracts. Tears were collected without previous stimulation. Detection of sIgA showed 65.9% sensitivity (95% CI = 54.5-74.4), 71.6% specificity (95% CI = 59.8-81.2), a positive predictive value of 72% (95% CI = 60.3-81.5) and a negative predictive value of 65.4% (95% CI = 54.0-75.4). sIgA reactivity was higher in the tears of patients with active posterior uveitis due to T. gondii (p < 0.05). The test is useful for differentiating active posterior uveitis due to toxoplasmosis from uveitis caused by other diseases.

Genetic diversity of Toxoplasma gondii in animals and humans

USDA-ARS?s Scientific Manuscript database

Toxoplasma gondii is one of the most common parasites of domestic, wild, and companion animals, and it also infects approximately 25% of the world’s human population. T. gondii has a complex life cycle. Sexual development occurs only in the cat gut, while asexual replication and transmission occur i...

On the determination of Toxoplasma gondii virulence in mice

USDA-ARS?s Scientific Manuscript database

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...

Isolation and genetic characterization of viable Toxoplasma gondii from tissues and feces of cats from the central region of China.

PubMed

Yang, Yurong; Ying, Yuqing; Verma, S K; Cassinelli, A B M; Kwok, O C H; Liang, Hongde; Pradhan, A K; Zhu, X Q; Su, C; Dubey, J P

2015-07-30

Cats are important in the epidemiology of toxoplasmosis because they are the only definitive hosts that excrete environmentally resistant Toxoplasma gondii oocysts. Little is known of feline toxoplasmosis in China and most of the literature is in Chinese. Here we summarized all published reports on feline toxoplasmosis in English and report first identification of oocyst excretion by naturally infected cats in China. Unfrozen tissues of 42 cats and feces of 360 cats from China were bioassayed in mice for isolation of T. gondii. Antibodies to T. gondii were found in 21 of 42 (50%) of cats by the modified agglutination test (cut-off 1:25). Viable T. gondii was isolated from tissues of eight of 21 seropositive but not from 21 seronegative (<1:25) cats. Viable T. gondii was isolated from feces of one cat. DNA derived from cell cultured tachyzoites of all nine T. gondii isolates was characterized by PCR-RFLP at 10 loci (SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico). Four genotypes were found; the genotypes of tissue isolates were ToxoDB #9 in six, ToxoDB #2 in one, and ToxoDB #17 in one. The fecal isolate was ToxoDB #1.To our knowledge, the present study is the first isolation of T. gondii from cat feces from China. Copyright © 2015. Published by Elsevier B.V.

Immunization with a DNA vaccine encoding Toxoplasma gondii Superoxide dismutase (TgSOD) induces partial immune protection against acute toxoplasmosis in BALB/c mice.

PubMed

Liu, Yuan; Cao, Aiping; Li, Yawen; Li, Xun; Cong, Hua; He, Shenyi; Zhou, Huaiyu

2017-06-07

Toxoplasma gondii (T. gondii) is an obligate intracellular protozoan parasite that infects all warm-blooded animals including humans and causes toxoplasmosis. An effective vaccine could be an ideal choice for preventing and controlling toxoplasmosis. T. gondii Superoxide dismutase (TgSOD) might participate in affecting the intracellular growth of both bradyzoite and tachyzoite forms. In the present study, the TgSOD gene was used to construct a DNA vaccine (pEGFP-SOD). TgSOD gene was amplified and inserted into eukaryotic vector pEGFP-C1 and formed the DNA vaccine pEGFP-SOD. Then the BALB/c mice were immunized intramuscularly with the DNA vaccine and those injected with pEGFP-C1, PBS or nothing were treated as controls. Four weeks after the last immunization, all mouse groups followed by challenging intraperitoneally with tachyzoites of T. gondii ME49 strain. Results showed higher levels of total IgG, IgG2α in the sera and interferon gamma (IFN-γ) in the splenocytes from pEGFP-SOD inoculated mice than those unvaccinated, or inoculated with either empty plasmid vector or PBS. The proportions of CD4 + T cells and CD8 + T cells in the spleen from pEGFP-SOD inoculated mice were significantly (p < 0.05) increased compared to control groups. In addition, the survival time of mice immunized with pEGFP-SOD was significantly prolonged as compared to the controls (p < 0.05) although all the mice died. The present study revealed that the DNA vaccine triggered strong humoral and cellular immune responses, and aroused partial protective immunity against acute T. gondii infection in BALB/c mice. The collective data suggests the SOD may be a potential vaccine candidate for further development.

Discovery of New Inhibitors of Toxoplasma gondii via the Pathogen Box

PubMed Central

Spalenka, Jérémy; Escotte-Binet, Sandie; Bakiri, Ali; Hubert, Jane; Renault, Jean-Hugues; Velard, Frédéric; Duchateau, Simon; Aubert, Dominique; Huguenin, Antoine

2017-01-01

ABSTRACT Toxoplasma gondii is a cosmopolitan protozoan parasite which affects approximately 30% of the population worldwide. The drugs currently used against toxoplasmosis are few in number and show several limitations, such as drug intolerance, poor bioavailability, or drug resistance mechanism developed by the parasite. Thus, it is important to find new compounds able to inhibit parasite invasion or proliferation. In this study, the 400 compounds of the open-access Pathogen Box, provided by the Medicines for Malaria Venture (MMV) foundation, were screened for their anti-Toxoplasma gondii activity. A preliminary in vitro screening performed over 72 h by an enzyme-linked immunosorbent assay (ELISA) revealed 15 interesting compounds that were effective against T. gondii at 1 μM. Their cytotoxicity was estimated on Vero cells, and their 50% inhibitory concentrations (IC50) were further calculated. As a result, eight anti-Toxoplasma gondii compounds with an IC50 of less than 2 μM and a selectivity index (SI) value of greater than 4 were identified. The most active was MMV675968, showing an IC50 of 0.02 μM and a selectivity index value equal to 275. Two other compounds, MMV689480 and MMV687807, also showed a good activity against T. gondii, with IC50s of 0.10 μM (SI of 86.6) and 0.15 μM (SI of 11.3), respectively. Structure-activity relationships for the eight selected compounds also were discussed on the basis of fingerprinting similarity measurements using the Tanimoto method. The anti-Toxoplasma gondii compounds highlighted here represent potential candidates for the development of new drugs that could be used against toxoplasmosis. PMID:29133550

Discovery of New Inhibitors of Toxoplasma gondii via the Pathogen Box.

PubMed

Spalenka, Jérémy; Escotte-Binet, Sandie; Bakiri, Ali; Hubert, Jane; Renault, Jean-Hugues; Velard, Frédéric; Duchateau, Simon; Aubert, Dominique; Huguenin, Antoine; Villena, Isabelle

2018-02-01

Toxoplasma gondii is a cosmopolitan protozoan parasite which affects approximately 30% of the population worldwide. The drugs currently used against toxoplasmosis are few in number and show several limitations, such as drug intolerance, poor bioavailability, or drug resistance mechanism developed by the parasite. Thus, it is important to find new compounds able to inhibit parasite invasion or proliferation. In this study, the 400 compounds of the open-access Pathogen Box, provided by the Medicines for Malaria Venture (MMV) foundation, were screened for their anti- Toxoplasma gondii activity. A preliminary in vitro screening performed over 72 h by an enzyme-linked immunosorbent assay (ELISA) revealed 15 interesting compounds that were effective against T. gondii at 1 μM. Their cytotoxicity was estimated on Vero cells, and their 50% inhibitory concentrations (IC 50 ) were further calculated. As a result, eight anti- Toxoplasma gondii compounds with an IC 50 of less than 2 μM and a selectivity index (SI) value of greater than 4 were identified. The most active was MMV675968, showing an IC 50 of 0.02 μM and a selectivity index value equal to 275. Two other compounds, MMV689480 and MMV687807, also showed a good activity against T. gondii , with IC 50 s of 0.10 μM (SI of 86.6) and 0.15 μM (SI of 11.3), respectively. Structure-activity relationships for the eight selected compounds also were discussed on the basis of fingerprinting similarity measurements using the Tanimoto method. The anti- Toxoplasma gondii compounds highlighted here represent potential candidates for the development of new drugs that could be used against toxoplasmosis. Copyright © 2018 Spalenka et al.

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

USDA-ARS?s Scientific Manuscript database

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...

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.

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 ...

[The seroprevalence of Toxoplasma gondii in women from Sanliurfa, a province with a high raw meatball consumption].

PubMed

Tekay, Fikret; Ozbek, Erdal

2007-01-01

Toxoplasma gondii is an obligate intracellular protozoan that can infect all kind of birds and all mammals including humans and is common throughout the world. The prevalence varies according to social and cultural habits, pet cats in homes and geographic factors. Domestic cats are considered to be an important source of Toxoplasma gondii infection. From January to June 2006, the prevalence of toxoplasmosis was retrospectively monitored from blood samples that had been sent to our laboratory in order to determine the levels of IgM and IgG. All the subjects were women and 2,586 blood samples were investigated with the chemiluminescence immunoassay method. The rates of Toxoplasma gondii IgM antibodies were found to be 3.0% (78/2,586) and that of Toxoplasma gondii IgG antibodies, 69.5% (1.798/2,586). The total rate of positivity of Toxoplasma gondii antibodies was 69.6% (1,801/2,586) and the negativity, 30.4% (785/2,586). The highest positive rates have been reported in the southeastern region of Turkey and the 69.6% detected in our study seems to be the highest rate. Raw meatball consumption is common in our region and raw meat has a high risk of Toxoplasma gondii infection by direct ingestion of tissue cysts. As a result we consider that the high frequency of Toxoplasma gondii seropositivity in this region is due to raw meatball consumption.

Stress sensitivity in Toxoplasma gondii is linked to its uniquely flexible life cycle

USDA-ARS?s Scientific Manuscript database

Hammondia hammondi is the nearest relative of Toxoplasma gondii, but unlike T. gondii is obligately heteroxenous. We have compared H. hammondi and T. gondii development in vitro and identified multiple H. hammondi-specific growth states. Despite replicating slower than T. gondii, H. hammondi was res...

Mechanics of the Toxoplasma gondii oocyst wall

USDA-ARS?s Scientific Manuscript database

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...

Seroepidemiology of Toxoplasma gondii Infection among healthy blood donors in Taiwan.

PubMed

Chiang, Ting-Yi; Hsieh, Hwei-Ho; Kuo, Ming-Chu; Chiu, Kai-Tse; Lin, Wei-Chen; Fan, Chia-Kwung; Fang, Chi-Tai; Ji, Dar-Der

2012-01-01

Toxoplasma gondii is an opportunistic, zoonotic pathogen with a worldwide distribution. There are large variations in the seroprevalence of T. gondii infection in different regions of the world. Although toxoplasmosis became a notifiable communicable disease in Taiwan in 2007, little is known about its epidemiology among the general population. This cross-sectional study aimed to survey the seroprevalence of T. gondii infection and its risk factors among healthy blood donors in Taiwan. Through collaborating with the Taiwan Blood Services Foundation, a total of 1,783 healthy blood donors from all six-branch blood service centers participated in this study. The blood samples were tested for the presence of T. gondii antibodies and DNA using enzyme immunoassays and real-time PCR, respectively. Structured questionnaires were used to gather information on risk factors for T. gondii infection. Of the 1,783 participants, 166 (9.3%) tested positive for anti-Toxoplasma IgG, while 5 (0.28%) tested positive for anti-Toxoplasma IgM. The five IgM positive donors had high avidity antibodies suggestive of past infection. No active parasitemia was detected by real-time PCR assays. Multivariate logistic regression showed that undercooked pork meat consumption (adjusted odds ratio [OR] = 2.9; 95% confidence interval [CI]: 1.3-6.5), raw mussels consumption (adjusted OR = 5.3; 95% CI: 1.5-19.1), having a cat in the household (adjusted OR = 2.0; 95% CI: 1.2-3.2), a lower education level (adjusted OR = 1.6; 95% CI: 1.1-2.3), and donation place in eastern Taiwan (adjusted OR = 2.5; 95% CI: 1.6-3.9) were independent risk factors for Toxoplasma seropositivity. These findings provide information on the seroprevalence and epidemiology of T. gondii infection among healthy blood donors in Taiwan.

Seroepidemiology of Toxoplasma gondii Infection among Healthy Blood Donors in Taiwan

PubMed Central

Chiang, Ting-Yi; Hsieh, Hwei-Ho; Kuo, Ming-Chu; Chiu, Kai-Tse; Lin, Wei-Chen; Fan, Chia-Kwung; Fang, Chi-Tai; Ji, Dar-Der

2012-01-01

Toxoplasma gondii is an opportunistic, zoonotic pathogen with a worldwide distribution. There are large variations in the seroprevalence of T. gondii infection in different regions of the world. Although toxoplasmosis became a notifiable communicable disease in Taiwan in 2007, little is known about its epidemiology among the general population. This cross-sectional study aimed to survey the seroprevalence of T. gondii infection and its risk factors among healthy blood donors in Taiwan. Through collaborating with the Taiwan Blood Services Foundation, a total of 1,783 healthy blood donors from all six-branch blood service centers participated in this study. The blood samples were tested for the presence of T. gondii antibodies and DNA using enzyme immunoassays and real-time PCR, respectively. Structured questionnaires were used to gather information on risk factors for T. gondii infection. Of the 1,783 participants, 166 (9.3%) tested positive for anti-Toxoplasma IgG, while 5 (0.28%) tested positive for anti-Toxoplasma IgM. The five IgM positive donors had high avidity antibodies suggestive of past infection. No active parasitemia was detected by real-time PCR assays. Multivariate logistic regression showed that undercooked pork meat consumption (adjusted odds ratio [OR] = 2.9; 95% confidence interval [CI]: 1.3–6.5), raw mussels consumption (adjusted OR = 5.3; 95% CI: 1.5–19.1), having a cat in the household (adjusted OR = 2.0; 95% CI: 1.2–3.2), a lower education level (adjusted OR = 1.6; 95% CI: 1.1–2.3), and donation place in eastern Taiwan (adjusted OR = 2.5; 95% CI: 1.6–3.9) were independent risk factors for Toxoplasma seropositivity. These findings provide information on the seroprevalence and epidemiology of T. gondii infection among healthy blood donors in Taiwan. PMID:23133557

Evaluation of a real-time PCR assay based on the single-copy SAG1 gene for the detection of Toxoplasma gondii.

PubMed

Yu, Haijie; Huang, Bin; Zhuo, Xunhui; Chen, Xueqiu; Du, Aifang

2013-11-08

Real-time PCR-based detection of Toxoplasma gondii is very sensitive and convenient for diagnosing toxoplasmosis. However, the performance of the PCR assays could be influenced by the target gene chosen. Here we evaluate a real-time PCR assay using double-stranded DNA dyes (SYBR(®) Green I assay) with a new set of primers targeting the SAG1 gene for the fast and specific detection of T. gondii. The assay showed higher sensitivity than conventional PCR protocols using T. gondii DNA as template. The detection limit of the developed real-time PCR assay was in the order of 1 tachyzoite. The assay was also assessed by experimentally infected mice and showed positive results for blood (25%), spleen (50%) and lung (50%) as early as 1 dpi. The specificity of the assay was confirmed by using DNA from Neospora caninum, Escherichia coli, Babesia bovis, Trypanosoma brucei, Cryptosporidium parvum, and Toxocara canis. Assay applicability was successfully tested in blood samples collected from slaughtered pigs. These results indicate that, based on SYBR(®) green I, the quantitative SAG1 assay may also be useful in the study of the pathogenicity, immunoprophylaxis, and treatment of T. gondii. Copyright © 2013 Elsevier B.V. All rights reserved.

Isolation and RFLP Genotyping of Toxoplasma gondii in Free-Range Chickens (Gallus domesticus) in Grenada, West Indies, Revealed Widespread and Dominance of Clonal Type III Parasites.

PubMed

Chikweto, Alfred; Sharma, Ravindra N; Tiwari, Keshaw P; Verma, Shiv K; Calero-Bernal, Rafael; Jiang, Tiantian; Su, Chunlei; Kwok, Oliver C; Dubey, Jitender P

2017-02-01

The objectives of the present cross-sectional study were to isolate and genotype Toxoplasma gondii in free-range chickens from Grenada, West Indies. Using the modified agglutination test, antibodies to T. gondii were found in 39 (26.9%) of 145 free-range chickens with titers of 25 in 7 chickens, 50 in 6 chickens, 100 in 2 chickens, and 200 or higher in 24 chickens. The hearts of the 39 seropositive chickens were bioassayed in mice; viable T. gondii was isolated from 20 and further propagated in cell culture. Genotyping 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 4 genotypes, including ToxoDB PCR-RFLP no. 2 (Type III), no. 7, no. 13, and no. 259 (new). These results indicated that T. gondii population genetics in free-range chickens seems to be moderately diverse with ToxoDB no. 2 (Type III) as the most frequent (15/20 = 75%) compared to other genotypes in Grenada.

Immunization of lambs with the S48 strain of Toxoplasma gondii reduces tissue cyst burden following oral challenge with a complete strain of the parasite.

PubMed

Katzer, Frank; Canton, German; Burrells, Alison; Palarea-Albaladejo, Javier; Horton, Ben; Bartley, Paul M; Pang, Yvonne; Chianini, Francesca; Innes, Elisabeth A; Benavides, Julio

2014-09-15

This study evaluates the influence of immunizing lambs with the incomplete S48 strain of Toxoplasma gondii, on parasite dissemination following a live oral challenge with a complete strain of T. gondii (M4). Lambs were culled at 14, 28 and 42 days post challenge. Parasite DNA was detected at significantly (p<0.0001) lower levels in samples from the vaccinated/challenged group (0% in heart and 5.9% in skeletal muscles), when compared to the non-vaccinated/challenged animals (75% heart, 87.9% skeletal muscle). S48 T. gondii DNA was found in muscle or lymph nodes until 42 days post infection, suggesting that parasite DNA or tachyzoites could persist longer after immunization than previously thought. Non-vaccinated/challenged animals showed more frequent lesions in muscles and central nervous system than the vaccinated animals. These results demonstrate that vaccination of lambs with the incomplete S48 T. gondii strain, can protect against establishment of tissue cysts following challenge with a complete strain of T. gondii. Consumption of undercooked meat containing T. gondii cysts is a major route of transmission to people, therefore vaccination of food animals may improve the safety of meat for human consumption. Copyright © 2014 Elsevier B.V. All rights reserved.

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

Long-term antibody responses of cats fed toxoplasma gondii tissue cysts.

PubMed

Dubey, J P; Lappin, M R; Thulliez, P

1995-12-01

As part of a long-term study on immunity to oocyst shedding, 12 4-6-mo-old cats were inoculated orally with tissue cysts of the ME-49 strain (6 cats) or the TS-2 strain (6 cats) of Toxoplasma gondii. Two cats fed the ME-49 strain died or were killed because of acute toxoplasmosis 12 and 13 days after inoculation (DAI), respectively. On day 39 after primary infection, 5 cats (2 infected with the ME-49 strain and 3 infected with the TS-2 strain) were challenged orally with tissue cysts of the ME-49 strain. One cat died following rechallenge infection due to causes unrelated to toxoplasmosis. Seventy-seven months after primary infection, the remaining 9 cats were challenged orally with tissue cysts of the P89 strain of T. gondii. Blood samples were obtained weekly or monthly and sera were analyzed for antibodies to T. gondii using the modified agglutination test (MAT), the Sabin-Feldman dye test (DT), and the enzyme-linked immunosorbent assay (ELISA) for IgM (IgM-ELISA) or IgG (IgG-ELISA). The MAT was performed using both formalin-fixed (FF) and acetone-fixed (AF) tachyzoites. The MAT (FF) was the most sensitive test; cats seroconverted within 14 DAI and high titers (> 10,000) persisted > 6 yr, although cats had no clinical signs. The MAT titers using the AF detected recent exposure and titers declined sharply after 2 mo postinoculation. DT and ELISA titers were lower and developed slower than MAT titers. Fluctuations in antibody titers were limited to 8-fold during the 6-yr observation period. Anamnestic serum antibody responses were seen in 2 cats after the final challenge, but not after first challenge.

Toxoplasma gondii Requires Glycogen Phosphorylase for Balancing Amylopectin Storage and for Efficient Production of Brain Cysts.

PubMed

Sugi, Tatsuki; Tu, Vincent; Ma, Yanfen; Tomita, Tadakimi; Weiss, Louis M

2017-08-29

In immunocompromised hosts, latent infection with Toxoplasma gondii can reactivate from tissue cysts, leading to encephalitis. A characteristic of T. gondii bradyzoites in tissue cysts is the presence of amylopectin granules. The regulatory mechanisms and role of amylopectin accumulation in this organism are not fully understood. The T. gondii genome encodes a putative glycogen phosphorylase (TgGP), and mutants were constructed to manipulate the activity of TgGP and to evaluate the function of TgGP in amylopectin storage. Both a stop codon mutant (Pru/TgGP S25stop [expressing a Ser-to-stop codon change at position 25 in TgGP]) and a phosphorylation null mutant (Pru/TgGP S25A [expressing a Ser-to-Ala change at position 25 in TgGp]) mutated at Ser25 displayed amylopectin accumulation, while the phosphorylation-mimetic mutant (Pru/TgGP S25E [expressing a Ser-to-Glu change at position 25 in TgGp]) had minimal amylopectin accumulation under both tachyzoite and bradyzoite growth conditions. The expression of active TgGP S25S or TgGP S25E restored amylopectin catabolism in Pru/TgGP S25A To understand the relation between GP and calcium-dependent protein kinase 2 (CDPK2), which was recently reported to regulate amylopectin consumption, we knocked out CDPK2 in these mutants. Pru Δcdpk2 /TgGP S25E had minimal amylopectin accumulation, whereas the Δcdpk2 phenotype in the other GP mutants and parental lines displayed amylopectin accumulation. Both the inactive S25A and hyperactive S25E mutant produced brain cysts in infected mice, but the numbers of cysts produced were significantly less than the number produced by the S25S wild-type GP parasite. Complementation that restored amylopectin regulation restored brain cyst production to the control levels seen in infected mice. These data suggest that T. gondii requires tight regulation of amylopectin expression for efficient production of cysts and persistent infections and that GP phosphorylation is a regulatory mechanism

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

The sero-prevalence of Toxoplasma gondii in British marine mammals.

PubMed

Forman, Dan; West, Nathan; Francis, Janet; Guy, Edward

2009-03-01

Serum samples from 101 stranded or bycatch cetaceans from British waters were screened for Toxoplasma gondii-specific antibodies using the Sabin Feldman Dye Test. Relatively high seropositivity was recorded in short-beaked Delphinus delphis and this study presents the first documented case of Toxoplasma in a humpback whale Megaptera novaeangliae.

Toxoplasma gondii seroprevalence in pet cats in Norway and risk factors for seropositivity.

PubMed

Sævik, Bente Kristin; Krontveit, Randi Ingebjørg; Eggen, Kristine P; Malmberg, Nina; Thoresen, Stein I; Prestrud, Kristin W

2015-12-01

The aims of the study were to estimate Toxoplasma gondii seroprevalence in pet cats in Norway and to evaluate risk factors for seropositivity. Additionally, serum biochemistry and haematological variables for T gondii seropositive and seronegative cats were compared. A convenience sample of surplus sera submitted to the Central Laboratory, Norwegian University of Life Sciences, was collected. The samples were from healthy cats and cats with a variety of diseases. Analyses for IgG antibodies to T gondii were performed with a commercial direct agglutination test, with 1:40 as the threshold value. For risk factor analysis a logistic regression model of the relationship between predictors and the outcome was applied. One hundred and ninety-six of 478 cats were seropositive for T gondii, and the estimated seroprevalence in the study sample was 41.0% (95% confidence interval 36.6-45.4). Compared with domestic cats, pedigree cats had reduced risk for Toxoplasma seropositivity (odds ratio [OR] 0.42). Males had increased risk (OR 1.63) compared with females. The effect of age was highly significant, and an increase in the cats' age across the interquartile range (IQR; 52-160 months/4-13 years of age) doubled the risk of Toxoplasma seropositivity (OR 2.11). The risk for Toxoplasma seropositivity among cats living in Oslo was significantly reduced (OR 0.51) when compared with the rest of Norway. Pet cats in Norway appear to be commonly exposed to T gondii. Signalment and geographical region influenced the odds of Toxoplasma seropositivity, whereas health status did not. © ISFM and AAFP 2015.

Prime-boost vaccination with toxoplasma lysate antigen, but not with a mixture of recombinant protein antigens, leads to reduction of brain cyst formation in BALB/c mice.

PubMed

Wagner, Angelika; Schabussova, Irma; Ruttkowski, Bärbel; Peschke, Roman; Kur, Józef; Kundi, Michael; Joachim, Anja; Wiedermann, Ursula

2015-01-01

Infection with the ubiquitous parasite Toxoplasma gondii is a threat for immunocompromised patients and pregnant women and effective immune-prophylaxis is still lacking. Here we tested a mixture of recombinant T. gondii antigens expressed in different developmental stages, i.e., SAG1, MAG1 and GRA7 (SMG), and a lysate derived from T. gondii tachyzoites (TLA) for prophylactic vaccination against cyst formation. Both vaccine formulations were applied systemically followed by an oral TLA-booster in BALB/c mice. Systemic priming with SMG and oral TLA-booster did not show significant induction of protective immune responses. In contrast, systemic priming and oral booster with TLA induced higher levels of Toxoplasma-specific IgG, IgG1 and IgG2a in sera as well as high levels of Toxoplasma-specific IgG1 in small intestines. Furthermore, high levels of Toxoplasma-specific Th1-, Th17- and Th2-associated cytokines were only detected in restimulated splenocytes of TLA-vaccinated mice. Importantly, in mice orally infected with T. gondii oocysts, only TLA-vaccination and booster reduced brain cysts. Furthermore, sera from these mice reduced tachyzoites invasion of Vero cells in vitro, indicating that antibodies may play a critical role for protection against Toxoplasma infection. Additionally, supernatants from splenocyte cultures of TLA-vaccinated mice containing high levels of IFN-γ lead to substantial production of nitric oxide (NO) after incubation with macrophages in vitro. Since NO is involved in the control of parasite growth, the high levels of IFN-γ induced by vaccination with TLA may contribute to the protection against T. gondii. In conclusion, our data indicate that prime-boost approach with TLA, but not with the mixture of recombinant antigens SMG, induces effective humoral and cellular Toxoplasma-specific responses and leads to significant reduction of cerebral cysts, thereby presenting a viable strategy for further vaccine development against T. gondii

Prime-Boost Vaccination with Toxoplasma Lysate Antigen, but Not with a Mixture of Recombinant Protein Antigens, Leads to Reduction of Brain Cyst Formation in BALB/c Mice

PubMed Central

Wagner, Angelika; Schabussova, Irma; Ruttkowski, Bärbel; Peschke, Roman; Kur, Józef; Kundi, Michael; Joachim, Anja; Wiedermann, Ursula

2015-01-01

Introduction Infection with the ubiquitous parasite Toxoplasma gondii is a threat for immunocompromised patients and pregnant women and effective immune-prophylaxis is still lacking. Methods Here we tested a mixture of recombinant T. gondii antigens expressed in different developmental stages, i.e., SAG1, MAG1 and GRA7 (SMG), and a lysate derived from T. gondii tachyzoites (TLA) for prophylactic vaccination against cyst formation. Both vaccine formulations were applied systemically followed by an oral TLA-booster in BALB/c mice. Results Systemic priming with SMG and oral TLA-booster did not show significant induction of protective immune responses. In contrast, systemic priming and oral booster with TLA induced higher levels of Toxoplasma-specific IgG, IgG1 and IgG2a in sera as well as high levels of Toxoplasma-specific IgG1 in small intestines. Furthermore, high levels of Toxoplasma-specific Th1-, Th17- and Th2-associated cytokines were only detected in restimulated splenocytes of TLA-vaccinated mice. Importantly, in mice orally infected with T. gondii oocysts, only TLA-vaccination and booster reduced brain cysts. Furthermore, sera from these mice reduced tachyzoites invasion of Vero cells in vitro, indicating that antibodies may play a critical role for protection against Toxoplasma infection. Additionally, supernatants from splenocyte cultures of TLA-vaccinated mice containing high levels of IFN-γ lead to substantial production of nitric oxide (NO) after incubation with macrophages in vitro. Since NO is involved in the control of parasite growth, the high levels of IFN-γ induced by vaccination with TLA may contribute to the protection against T. gondii. Conclusion In conclusion, our data indicate that prime-boost approach with TLA, but not with the mixture of recombinant antigens SMG, induces effective humoral and cellular Toxoplasma-specific responses and leads to significant reduction of cerebral cysts, thereby presenting a viable strategy for further

Experimental Toxoplasmosis in Rats Induced Orally with Eleven Strains of Toxoplasma gondii of Seven Genotypes: Tissue Tropism, Tissue Cyst Size, Neural Lesions, Tissue Cyst Rupture without Reactivation, and Ocular Lesions.

PubMed

Dubey, Jitender P; Ferreira, Leandra R; Alsaad, Mohammad; Verma, Shiv K; Alves, Derron A; Holland, Gary N; McConkey, Glenn A

2016-01-01

The protozoan parasite Toxoplasma gondii is one of the most widely distributed and successful parasites. Toxoplasma gondii alters rodent behavior such that infected rodents reverse their fear of cat odor, and indeed are attracted rather than repelled by feline urine. The location of the parasite encysted in the brain may influence this behavior. However, most studies are based on the highly susceptible rodent, the mouse. Latent toxoplasmosis was induced in rats (10 rats per T. gondii strains) of the same age, strain, and sex, after oral inoculation with oocysts (natural route and natural stage of infection) of 11 T. gondii strains of seven genotypes. Rats were euthanized at two months post inoculation (p.i.) to investigate whether the parasite genotype affects the distribution, location, tissue cyst size, or lesions. Tissue cysts were enumerated in different regions of the brains, both in histological sections as well in saline homogenates. Tissue cysts were found in all regions of the brain. The tissue cyst density in different brain regions varied extensively between rats with many regions highly infected in some animals. Overall, the colliculus was most highly infected although there was a large amount of variability. The cerebral cortex, thalamus, and cerebellum had higher tissue cyst densities and two strains exhibited tropism for the colliculus and olfactory bulb. Histologically, lesions were confined to the brain and eyes. Tissue cyst rupture was frequent with no clear evidence for reactivation of tachyzoites. Ocular lesions were found in 23 (25%) of 92 rat eyes at two months p.i. The predominant lesion was focal inflammation in the retina. Tissue cysts were seen in the sclera of one and in the optic nerve of two rats. The choroid was not affected. Only tissue cysts, not active tachyzoite infections, were detected. Tissue cysts were seen in histological sections of tongue of 20 rats but not in myocardium and leg muscle. This study reevaluated in depth the

Identification of proteins interacting with Toxoplasma SRCAP by yeast two-hybrid screening.

PubMed

Nallani, Karuna C; Sullivan, William J

2005-03-01

Toxoplasma gondii is an opportunistic protozoan parasite that differentiates into latent cysts (bradyzoite) that can be reactivated during immunosuppression. TgSRCAP (Toxoplasma gondii Snf2-related CBP activator protein) is a SWI2/SNF2 family chromatin remodeler whose expression increases during cyst development. Identifying the proteins associating with TgSRCAP during the pre-cyst stage (tachyzoite) will increase our understanding of how parasite differentiation is initiated. We employed the yeast two-hybrid system to identify proteins that may interact directly with TgSRCAP. A stretch of 1,060 amino acids between ATPase subdomains IV and V of TgSRCAP was chosen as "bait" since the corresponding region in human SRCAP interacts with other proteins, including CREB binding protein. We have identified several novel parasite-specific transcription factors predicted to be in the T. gondii genome. Metabolic enzymes that may participate in cyst development were also identified as interacting with TgSRCAP.

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.

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...

The neurotropic parasite Toxoplasma gondii increases dopamine metabolism

USDA-ARS?s Scientific Manuscript database

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...

Migration of Toxoplasma gondii–Infected Dendritic Cells across Human Retinal Vascular Endothelium

PubMed Central

Furtado, João M.; Bharadwaj, Arpita S.; Ashander, Liam M.; Olivas, Antoinette; Smith, Justine R.

2012-01-01

Purpose. Toxoplasma gondii, the parasite responsible for ocular toxoplasmosis, accesses the retina from the bloodstream. We investigated the dendritic cell as a potential taxi for T. gondii tachyzoites moving across the human retinal endothelium, and examined the participation of adhesion molecules and chemokines in this process. Methods. CD14-positive monocytes were isolated from human peripheral blood by antibody-mediated cell enrichment, and cultured in granulocyte-macrophage colony-stimulating factor and interleukin-4 to generate dendritic cells. Transmigration assays were performed over 18 hours in transwells seeded with human retinal endothelial cells and using dendritic cells exposed to laboratory or natural strains of T. gondii tachyzoites. Parasites were tagged with yellow fluorescent protein to verify infection. In some experiments, endothelial monolayers were preincubated with antibody directed against adhesion molecules, or chemokine was added to lower chambers of transwells. Results. Human monocyte–derived dendritic cell preparations infected with laboratory or natural strain T. gondii tachyzoites transmigrated in larger numbers across simulated human retinal endothelium than uninfected dendritic cells (P ≤ 0.0004 in 5 of 6 experiments). Antibody blockade of intercellular adhesion molecule (ICAM)–1, vascular cell adhesion molecule (VCAM)–1, and activated leukocyte cell adhesion molecule (ALCAM) inhibited transmigration (P ≤ 0.007), and CCL21 or CXCL10 increased transmigration (P ≤ 0.031). Conclusions. Transmigration of human dendritic cells across retinal endothelium is increased following infection with T. gondii. Movement may be impacted by locally produced chemokines and is mediated in part by ICAM-1, VCAM-1, and ALCAM. These findings have implications for development of novel therapeutics aimed at preventing retinal infection by T. gondii. PMID:22952125

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

USDA-ARS?s Scientific Manuscript database

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...

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

USDA-ARS?s Scientific Manuscript database

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...

Toxoplasma gondii seroprevalence in breeding pigs in Estonia.

PubMed

Santoro, Azzurra; Tagel, Maarja; Must, Kärt; Laine, Miia; Lassen, Brian; Jokelainen, Pikka

2017-12-11

Toxoplasma gondii is a widespread occurring parasite infecting warm-blooded animals, including pigs and humans. The aims of this study were to estimate the prevalence of anti-T. gondii antibodies and to evaluate risk factors for T. gondii seropositivity in breeding pigs raised in Estonia. Sera from 382 pigs were tested with a commercial direct agglutination test, using a cut-off titer of 40 for seropositivity, for the presence of anti-T. gondii immunoglobulin G antibodies. Twenty-two (5.8%) of the 382 pigs tested seropositive for T. gondii, and 6 of the 14 herds had at least one seropositive pig. The proportion of seropositive pigs within the herds ranged between 0 and 43%. Gender appeared as a significant factor, with sows having 5.6 times higher odds to be seropositive to T. gondii than boars. Seroprevalence did not increase with age. Anti-T. gondii antibodies were present in a substantial proportion of breeding pig herds in Estonia. On the other hand, the presence of herds without seropositive pigs illustrates that porcine T. gondii infections can be avoided even in a country where the parasite is endemic and common in several other host species.

Genetic approaches to defining pathogenesis of Toxoplasma gondii

USDA-ARS?s Scientific Manuscript database

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

Fatal toxoplasmosis and enteroepithelial stages of Toxoplasma gondii in a Pallas cat (Felis manul).

PubMed

Dubey, J P; Gendron-Fitzpatrick, A P; Lenhard, A L; Bowman, D

1988-11-01

Toxoplasma gondii was found in tissues of a six-year-old female Pallas cat (Felis manul) from the Milwaukee County Zoo. Toxoplasma gondii meronts (types D and E), gamonts, and oocysts were present in the epithelium of the small intestine. Numerous unsporulated oocysts were present in the intestinal lumen. The cat died of acute, overwhelming toxoplasmosis. Necrotic enteritis, multifocal necrotizing granulomatous hepatitis, and pneumonia were the prominent lesions.

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. © H. Ma et al., published by EDP Sciences, 2015.

Toxoplasma gondii: epidemiology, feline clinical aspects, and prevention

USDA-ARS?s Scientific Manuscript database

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...

Toxoplasma gondii acetyl-CoA synthetase is involved in fatty acid elongation (of long fatty acid chains) during tachyzoite life stages.

PubMed

Dubois, David; Fernandes, Stella; Amiar, Souad; Dass, Sheena; Katris, Nicholas J; Botté, Cyrille Y; Yamaryo-Botté, Yoshiki

2018-06-01

Apicomplexan parasites are pathogens responsible for major human diseases such as toxoplasmosis caused by Toxoplasma gondii and malaria caused by Plasmodium spp. Throughout their intracellular division cycle, the parasites require vast and specific amounts of lipids to divide and survive. This demand for lipids relies on a fine balance between de novo synthesized lipids and scavenged lipids from the host. Acetyl-CoA is a major and central precursor for many metabolic pathways, especially for lipid biosynthesis. T. gondii possesses a single cytosolic acetyl-CoA synthetase ( Tg ACS). Its role in the parasite lipid synthesis is unclear. Here, we generated an inducible Tg ACS KO parasite line and confirmed the cytosolic localization of the protein. We conducted 13 C-stable isotope labeling combined with mass spectrometry-based lipidomic analyses to unravel its putative role in the parasite lipid synthesis pathway. We show that its disruption has a minor effect on the global FA composition due to the metabolic changes induced to compensate for its loss. However, we could demonstrate that Tg ACS is involved in providing acetyl-CoA for the essential fatty elongation pathway to generate FAs used for membrane biogenesis. This work provides novel metabolic insight to decipher the complex lipid synthesis in T. gondii . Copyright © 2018 by the American Society for Biochemistry and Molecular Biology, Inc.

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. Copyright 2010 Elsevier B.V. All rights reserved.

First genetic characterization of Toxoplasma gondii in stray cats from Algeria.

PubMed

Yekkour, Feriel; Aubert, Dominique; Mercier, Aurélien; Murat, Jean-Benjamin; Khames, Mammar; Nguewa, Paul; Ait-Oudhia, Khatima; Villena, Isabelle; Bouchene, Zahida

2017-05-30

Toxoplasmosis is a parasitic disease with worldwide distribution and a major public health problem. In Algeria, no data are currently available about genotypes of Toxoplasma gondii isolated from animals or humans. The present study assesses for the first time the seroprevalence of toxoplasmosis in stray cats, and provides molecular characterization of T. gondii strains circulating in this feline population in Algiers, the capital city of Algeria. Sera from 96 stray cats were tested for the presence of antibodies against T. gondii using the modified agglutination test. The seroprevalence was 50% (48/96) using 1:6 as the positivity cut-off. Different organs samples from stray cats, including heart samples, were tested for the presence of Toxoplasma DNA using real-time PCR. T. Gondii DNA was detected in 90.6% (87/96) of hearts. Of these parasitic DNAs, 22 were submitted to genotyping through the analysis of 15 microsatellite markers. The identified genotypes (12 of 22) mainly belonged to the type II lineage. Copyright © 2017 Elsevier B.V. All rights reserved.

ELISA-seroprevalence of Toxoplasma gondii in draught horses in Greater Cairo, Egypt.

PubMed

Haridy, Fouad M; Shoukry, Nahla M; Hassan, Aly Awad; Morsy, Tosson A

2009-12-01

Toxoplasma gondii is one of the important zoonotic parasites of worldwide. In this paper the seroprevalence of T. gondii in draught horses (3-15 years) including 90 males and 10 females in the first half of the year 2009 was studied. The result showed that the overall ELISA-T. gondii antibodies were 25% of the horses in Greater Cairo, 50% (females) and 22.2% (males).

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

USDA-ARS?s Scientific Manuscript database

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...

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

USDA-ARS?s Scientific Manuscript database

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 ...

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

USDA-ARS?s Scientific Manuscript database

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...

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

USDA-ARS?s Scientific Manuscript database

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....

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

USDA-ARS?s Scientific Manuscript database

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

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

USDA-ARS?s Scientific Manuscript database

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...

[Tuberculosis of the lymphatic nodes and coexisting invasion with Toxoplasma gondii].

PubMed

Kociecka, W; Simon, E; Szymaczek-Meyer, L; Pakuła, M

Six cases of the peripheral lymphatic nodes tuberculosis with positive serologic reactions to Toxoplasma gondii antigen are presented. It was shown, that independently of a complex of clinical examinations histologic examination is decisive for the diagnosis of lymphatic nodes tuberculosis with coexisting toxoplasmosis. A positive serologic reaction with T. gondii antigen in patients with lymphatic nodes tuberculosis may reflect inactive infection with T. gondii. Use of anti-toxoplasmosis drugs may be not necessary in such cases.

Isolation of Toxoplasma gondii from horse meat in Egypt.

PubMed

Shaapan, R M; Ghazy, A A

2007-01-01

Portions of heart, liver, skeletal and diaphragmatic muscles obtained from 150 slaughtered horses at Giza-Zoo abattoir were used for bioassays in mice and cats. T. gondii tachyzoites were isolated successfully from the peritoneal exudates of the inoculated mice 6-8 days post inoculation with pooled horse tissues. Whereas, T. gondii tissue cysts containing bradyzoites were detected in the impression smears of mice brain on the 45th days or more post infection. The oocysts were detected in feces of cats 3-6 days post feeding on horse tissues containing tissue cysts. The oocysts became sporulated within 3-5 days in 2.5% Potassium dichromate. A total of 79 out of 150 horse meat samples were found to be infected with an incidence rate of 52.6 %. This is the first trial for isolation of T. gondii infective stages from horses in Egypt. Moreover, this study pointed out to the high infection rate of T. gondii in horse meat which may be considered as an important source of infection to wild zoo-animals in Egypt and humans in some countries if consumed raw or insufficiently cooked.

The history and life cycle of Toxoplasma gondii

USDA-ARS?s Scientific Manuscript database

Infections by the protozoan parasite Toxoplasma gondii are widely prevalent in humans and other animals on all continents. There are many thousands of references to this parasite in the literature, and it is not possible to give equal treatment to all authors and discoveries. The objective of this c...

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.

Toxoplasma gondii Antigen-Pulsed-Dendritic Cell-Derived Exosomes Induce a Protective Immune Response against T. gondii Infection

PubMed Central

Aline, Fleur; Bout, Daniel; Amigorena, Sébastian; Roingeard, Philippe; Dimier-Poisson, Isabelle

2004-01-01

It was previously demonstrated that immunizing mice with spleen dendritic cells (DCs) that had been pulsed ex vivo with Toxoplasma gondii antigens triggers a systemic Th1-biased specific immune response and induces protection against infection. T. gondii can cause severe sequelae in the fetuses of mothers who acquire the infection during pregnancy, as well as life-threatening neuropathy in immunocompromised patients, in particular those with AIDS. Here, we investigate the efficacy of a novel cell-free vaccine composed of DC exosomes, which are secreted antigen-presenting vesicles that express functional major histocompatibility complex class I and II and T-cell-costimulatory molecules. They have already been shown to induce potent antitumor immune responses. We investigated the potential of DC2.4 cell line-derived exosomes to induce protective immunity against toxoplasmosis. Our data show that most adoptively transferred T. gondii-pulsed DC-derived exosomes were transferred to the spleen, elicited a strong systemic Th1-modulated Toxoplasma-specific immune response in vivo, and conferred good protection against infection. These findings support the possibility that DC-derived exosomes can be used for T. gondii immunoprophylaxis and for immunoprophylaxis against many other pathogens. PMID:15213158

Toxoplasma gondii infection in Kyrgyzstan: seroprevalence, risk factor analysis, and estimate of congenital and AIDS-related toxoplasmosis.

PubMed

Minbaeva, Gulnara; Schweiger, Alexander; Bodosheva, Aigerim; Kuttubaev, Omurbek; Hehl, Adrian B; Tanner, Isabelle; Ziadinov, Iskender; Torgerson, Paul R; Deplazes, Peter

2013-01-01

HIV-prevalence, as well as incidence of zoonotic parasitic diseases like cystic echinococcosis, has increased in the Kyrgyz Republic due to fundamental socio-economic changes after the breakdown of the Soviet Union. The possible impact on morbidity and mortality caused by Toxoplasma gondii infection in congenital toxoplasmosis or as an opportunistic infection in the emerging AIDS pandemic has not been reported from Kyrgyzstan. We screened 1,061 rural and 899 urban people to determine the seroprevalence of T. gondii infection in 2 representative but epidemiologically distinct populations in Kyrgyzstan. The rural population was from a typical agricultural district where sheep husbandry is a major occupation. The urban population was selected in collaboration with several diagnostic laboratories in Bishkek, the largest city in Kyrgyzstan. We designed a questionnaire that was used on all rural subjects so a risk-factor analysis could be undertaken. The samples from the urban population were anonymous and only data with regard to age and gender was available. Estimates of putative cases of congenital and AIDS-related toxoplasmosis in the whole country were made from the results of the serology. Specific antibodies (IgG) against Triton X-100 extracted antigens of T. gondii tachyzoites from in vitro cultures were determined by ELISA. Overall seroprevalence of infection with T. gondii in people living in rural vs. urban areas was 6.2% (95%CI: 4.8-7.8) (adjusted seroprevalence based on census figures 5.1%, 95% CI 3.9-6.5), and 19.0% (95%CI: 16.5-21.7) (adjusted 16.4%, 95% CI 14.1-19.3), respectively, without significant gender-specific differences. The seroprevalence increased with age. Independently low social status increased the risk of Toxoplasma seropositivity while increasing numbers of sheep owned decreased the risk of seropositivity. Water supply, consumption of unpasteurized milk products or undercooked meat, as well as cat ownership, had no significant influence

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

USDA-ARS?s Scientific Manuscript database

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 ...

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.

Toxoplasma gondii Infection in the United States, 2011-2014.

PubMed

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

2018-02-01

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

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

USDA-ARS?s Scientific Manuscript database

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...

Neutrophils, dendritic cells and Toxoplasma.

PubMed

Denkers, Eric Y; Butcher, Barbara A; Del Rio, Laura; Bennouna, Soumaya

2004-03-09

Toxoplasma gondii rapidly elicits strong Type 1 cytokine-based immunity. The necessity for this response is well illustrated by the example of IFN-gamma and IL-12 gene knockout mice that rapidly succumb to the effects of acute infection. The parasite itself is skilled at sparking complex interactions in the innate immune system that lead to protective immunity. Neutrophils are one of the first cell types to arrive at the site of infection, and the cells release several proinflammatory cytokines and chemokines in response to Toxoplasma. Dendritic cells are an important source of IL-12 during infection with T. gondii and other microbial pathogens, and they are also specialized for high-level antigen presentation to T lymphocytes. Tachyzoites express at least two types of molecules that trigger innate immune cell cytokine production. One of these involves Toll-like receptor/MyD88 pathways common to many microbial pathogens. The second pathway is less conventional and involves molecular mimicry between a parasite cyclophilin and host CC chemokine receptor 5-binding ligands. Neutrophils, dendritic cells and Toxoplasma work together to elicit the immune response required for host survival. Cytokine and chemokine cross-talk between parasite-triggered neutrophils and dendritic cells results in recruitment, maturation and activation of the latter. Neutrophil-empowered dendritic cells possess properties expected of highly potent antigen presenting cells that drive T helper 1 generation.

Toxoplasmic retinochoroiditis caused by Toxoplasma gondii strain ToxoDB#65.

PubMed

Brandão de Mattos, Cinara Cássia; Siqueira, Rubens Camargo; Frederico, Fábio Batista; Ferreira, Isabelle Martins Ribeiro; Ferreira, Ana Iara Costa; Previato, Mariana; Pereira-Chioccola, Vera Lucia; de Mattos, Luiz Carlos

2018-05-31

Ocular toxoplasmosis, caused by Toxoplasma gondii, is the most common cause of inflammation in the back of the eye. Analysis of the infecting strain may provide information regarding disease behavior and recurrence. Here, we describe clinical and epidemiological data for toxoplasmic retinochoroiditis in two Brazilian women infected by T. gondii strain ToxoDB#65, living in an urban region of São Paulo State, Brazil. Copyright © 2018 Elsevier B.V. All rights reserved.

ISOLATION OF TOXOPLASMA GONDII FROM ANIMALS IN DURANGO, MEXICO

USDA-ARS?s Scientific Manuscript database

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...

Serodiagnosis of Toxoplasma gondii infection in farm animals (horses, swine, and sheep) by enzyme-linked immunosorbent assay using chimeric antigens.

PubMed

Ferra, Bartłomiej; Holec-Gąsior, Lucyna; Kur, Józef

2015-10-01

Toxoplasma gondii infects all warm-blooded animals including humans, causing serious public health problems and great economic loss in the animal husbandry. Commonly used serological tests for diagnosis of toxoplasmosis involve preparation of whole Toxoplasma lysate antigen (TLA) from tachyzoites. The production of this antigen is associated with high costs and lengthy preparation and the possibility of staff infection. There are also some difficulties in the standardization of such tests. One approach in order to improve the diagnosis of T. gondii infection is to use recombinant chimeric antigens in place of the TLA, which was confirmed by studies in the serodiagnosis of toxoplasmosis in humans. In this paper, we assess, for the first time, the diagnostic utility of five T. gondii recombinant chimeric antigens (MIC1-MAG1-SAG1S, SAG1L-MIC1-MAG1, SAG2-GRA1-ROP1S, SAG2-GRA1-ROP1L, and GRA1-GRA2-GRA6) in immunoglobulin G (IgG) enzyme-linked immunosorbent assays (IgG ELISAs) with sera from three different groups of livestock animals (horses, pigs, and sheep). The reactivity of individual chimeric antigens was analyzed in relation to the results obtained in IgG ELISAs based on a mixture of three antigens (M1: rSAG1+rMIC1+rMAG1, M2: rSAG2+rGRA1+rROP1, and M3: rGRA1+rGRA2+rGRA6) and referenced to TLA. All chimeric antigens were characterized by high specificity (100%), and the sensitivity of the IgG ELISAs based on chimeric antigens was variable (between 28.4% and 100%) and mainly dependent on the animal species. The chimeric antigens were generally more reactive than mixtures of three antigens. The most effective for the diagnosis of toxoplasmosis was SAG2-GRA1-ROP1L, which can detect specific anti-T. gondii antibodies in 100%, 93.8%, and 100% of positive serum samples from horses, pigs, and sheep, respectively. The present study shows that recombinant chimeric antigens can be successfully used to diagnose T. gondii infection in farm animals, and can replace the commonly

Isolation of viable Toxoplasma gondii from guinea fowl (Numida meleagris) and rabbits from Brazil

USDA-ARS?s Scientific Manuscript database

Toxoplasma gondii was isolated from a feral guinea fowl (Numida meleagris) and domestic rabbits from Brazil for the first time. Serum and brains from 10 guinea fowl and 21 rabbits from Brazil were examined for T. gondii infection. Antibodies to T. gondii were found in 2 of 10 fowl and 2 of 21 rabbit...

Toxoplasma gondii seroprevalence varies by cat breed

PubMed Central

Hytönen, Marjo K.; Orro, Toomas; Lohi, Hannes; Jokelainen, Pikka

2017-01-01

Toxoplasma gondii is a widespread zoonotic parasite that is relevant for veterinary and public health. The domestic cat, the definitive host species with the largest worldwide population, has become evolutionarily and epidemiologically the most important host of T. gondii. The outcome of T. gondii infection is influenced by congenital and acquired host characteristics. We detected differences in T. gondii seroprevalence by cat breed in our previous studies. The aims of this study were to estimate T. gondii seroprevalence in selected domestic cat breeds, and to evaluate whether being of a certain breed is associated with T. gondii seropositivity, when the age and lifestyle of the cat are taken into account. The studied breeds were the Birman, British Shorthair, Burmese, Korat, Norwegian Forest Cat, Ocicat, Persian, and Siamese. Plasma samples were analyzed for the presence of immunoglobulin G antibodies against T. gondii with a commercial direct agglutination test at dilution 1:40. The samples were accompanied by owner-completed questionnaires that provided background data on the cats. Overall, 41.12% of the 1121 cats tested seropositive, and the seroprevalence increased with age. The Burmese had the lowest seroprevalence (18.82%) and the Persian had the highest (60.00%). According to the final multivariable logistic regression model, the odds to test seropositive were four to seven times higher in Birmans, Ocicats, Norwegian Forest Cats, and Persians when compared with the Burmese, while older age and receiving raw meat were also risk factors for T. gondii seropositivity. This study showed that T. gondii seroprevalence varies by cat breed and identified being of certain breeds, older age, and receiving raw meat as risk factors for seropositivity. PMID:28886182

Toxoplasma gondii seroprevalence varies by cat breed.

PubMed

Must, Kärt; Hytönen, Marjo K; Orro, Toomas; Lohi, Hannes; Jokelainen, Pikka

2017-01-01

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

Isolation and Genetic Characterization of Toxoplasma gondii from Black Bears (Ursus americanus), Bobcats (Lynx rufus), and Feral Cats (Felis catus) from Pennsylvania.

PubMed

Dubey, Jitender P; Verma, Shiv K; Calero-Bernal, Rafael; Cassinelli, Ana B; Kwok, Oliver C H; Van Why, Kyle; Su, Chunlei; Humphreys, Jan G

2015-01-01

Toxoplasma gondii infects virtually all warm-blooded hosts worldwide. Recently, attention has been focused on the genetic diversity of the parasite to explain its pathogenicity in different hosts. It has been hypothesized that interaction between feral and domestic cycles of T. gondii may increase unusual genotypes in domestic cats and facilitate transmission of potentially more pathogenic genotypes to humans, domestic animals, and wildlife. In the present study, we tested black bear (Ursus americanus), bobcat (Lynx rufus), and feral cat (Felis catus) from the state of Pennsylvania for T. gondii infection. Antibodies to T. gondii were found in 32 (84.2%) of 38 bears, both bobcats, and 2 of 3 feral cats tested by the modified agglutination test (cut off titer 1:25). Hearts from seropositive animals were bioassayed in mice, and viable T. gondii was isolated from 3 of 32 bears, 2 of 2 bobcats, and 2 of 3 feral cats. DNA isolated from culture-derived tachyzoites of these isolates was characterized using multilocus PCR-RFLP markers. Three genotypes were revealed, including ToxoDB PCR-RFLP genotype #1 or #3 (Type II, 1 isolate), #5 (Type 12, 3 isolates), and #216 (3 isolates), adding to the evidence of genetic diversity of T. gondii in wildlife in Pennsylvania. Pathogenicity of 3 T. gondii isolates (all #216, 1 from bear, and 2 from feral cat) was determined in outbred Swiss Webster mice; all three were virulent causing 100% mortality. Results indicated that highly mouse pathogenic strains of T. gondii are circulating in wildlife, and these strains may pose risk to infect human through consuming of game meat. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

High prevalence and genotypes of Toxoplasma gondii isolated from goats, from a retail meat store, destined for human consumption in the USA.

PubMed

Dubey, J P; Rajendran, C; Ferreira, L R; Martins, J; Kwok, O C H; Hill, D E; Villena, I; Zhou, H; Su, C; Jones, J L

2011-07-01

Little information is available concerning the presence of viable Toxoplasma gondii in tissues of goats worldwide. In the present study, hearts of 234 goats obtained from a local USA grocery store were examined for T. gondii infection. Blood clot or fluid removed from each heart was tested for antibodies to T. gondii by using the modified agglutination test (MAT). Antibodies to T. gondii were found in 125 (53.4%) of 234 goats, with titers of 1:5 in 20, 1:10 in 44, 1:20 in 16, 1:40 in five, 1:160 in five, 1:320 in five, and 1:640 or higher in 30 goats. Hearts of 112 goats (46 goats <1:5, and 66 goats 1:10 or higher) were used for isolation of viable T. gondii by bioassays in mice. For bioassays, 50 g of the myocardium were digested in an acid pepsin solution and the digest inoculated into mice; the recipient mice were examined for T. gondii infection. Toxoplasma gondii was isolated from 29 goats; from hearts of one of 46 with titers of <1:5, one of nine with titers of 1:10, one of three with titers of 1:40, and 26 of 40 with titers of 1:160 or higher. Two isolates were highly virulent to outbred Swiss Webster mice; all infected mice died of toxoplasmosis, irrespective of the dose. All T. gondii isolates were subsequently grown in cell cultures. Genotyping of the 29 T. gondii isolates using 10 PCR-restriction fragment length polymorphism markers (SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1 and Apico) from DNA obtained from cell culture grown tachyzoites revealed 12 genotypes. Nine isolates were clonal Type II lineage, four isolates had type II alleles at all loci except a type I allele at the Apico locus, and four isolates were clonal Type III. The remaining 12 strains were divided into nine atypical genotypes, including five new and four previously identified genotypes. DNA sequences of four introns (EF1, HP2, UPRT1 and UPRT7) and two genes (GRA6 and GRA7) were generated for the five new genotypes. Comparing these sequences with previously published data

Experimental Toxoplasmosis in Rats Induced Orally with Eleven Strains of Toxoplasma gondii of Seven Genotypes: Tissue Tropism, Tissue Cyst Size, Neural Lesions, Tissue Cyst Rupture without Reactivation, and Ocular Lesions

PubMed Central

Dubey, Jitender P.; Ferreira, Leandra R.; Alsaad, Mohammad; Verma, Shiv K.; Alves, Derron A.; Holland, Gary N.; McConkey, Glenn A.

2016-01-01

Background The protozoan parasite Toxoplasma gondii is one of the most widely distributed and successful parasites. Toxoplasma gondii alters rodent behavior such that infected rodents reverse their fear of cat odor, and indeed are attracted rather than repelled by feline urine. The location of the parasite encysted in the brain may influence this behavior. However, most studies are based on the highly susceptible rodent, the mouse. Methodology/Principal Findings Latent toxoplasmosis was induced in rats (10 rats per T. gondii strains) of the same age, strain, and sex, after oral inoculation with oocysts (natural route and natural stage of infection) of 11 T. gondii strains of seven genotypes. Rats were euthanized at two months post inoculation (p.i.) to investigate whether the parasite genotype affects the distribution, location, tissue cyst size, or lesions. Tissue cysts were enumerated in different regions of the brains, both in histological sections as well in saline homogenates. Tissue cysts were found in all regions of the brain. The tissue cyst density in different brain regions varied extensively between rats with many regions highly infected in some animals. Overall, the colliculus was most highly infected although there was a large amount of variability. The cerebral cortex, thalamus, and cerebellum had higher tissue cyst densities and two strains exhibited tropism for the colliculus and olfactory bulb. Histologically, lesions were confined to the brain and eyes. Tissue cyst rupture was frequent with no clear evidence for reactivation of tachyzoites. Ocular lesions were found in 23 (25%) of 92 rat eyes at two months p.i. The predominant lesion was focal inflammation in the retina. Tissue cysts were seen in the sclera of one and in the optic nerve of two rats. The choroid was not affected. Only tissue cysts, not active tachyzoite infections, were detected. Tissue cysts were seen in histological sections of tongue of 20 rats but not in myocardium and leg

Seroprevalence of Toxoplasma gondii infection Among Β-Thalassemia Major Pediatric Population: Implications for Transfusion Transmissible Toxoplasmosis.

PubMed

El-Tantawy, Nora; Darwish, Ahmad; Eissa, Eman

2018-05-14

Children with β-thalassemia major who regularly receive blood transfusion are at risk of developing transfusion-transmitted infection. Toxoplasmosis is a common and a serious parasitic disease with high prevalence and could be transmitted through blood transfusion from healthy asymptomatic donors. However, screening Toxoplasma gondii before blood donation has not been considered. To determine the prevalence of T. gondii antibodies among thalassemia children undergoing blood transfusion. In a case-control study, serum samples from 211 thalassemia children and 100 control children were investigated for Toxoplasma IgM and IgG using the enzyme-linked immunosorbent assay (ELISA). Positive serum samples for IgG antibodies to T. gondii were further subjected to IgG avidity ELISA. The seroprevalence of Toxoplasma infection among thalassemia children was 23.2% and 53.6% for IgM and IgG anti-Toxoplasma antibodies, respectively. Whereas in the contro group, the prevalence was 5% and 18% for IgM and IgG anti-Toxoplasma antibodies, respectively. There is a significant statistical difference between thalassemia and control groups regarding the prevalence of toxoplasmosis. From these positive IgG samples, 65.5% have low avidity indicating recent infection while 38.73% have high avidity indicating past infection. Due to the high serologic infection rate of toxoplasmosis among thalassemia pediatric population in this study with no existing effective therapies and no available T. gondii vaccine, appropriate strategies are critical for reducing the risk of that infection. Screening of blood for T. gondii antibodies should be considered before transmission to those children especially in countries with a high prevalence of toxoplasmosis.

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

USDA-ARS?s Scientific Manuscript database

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...

Detection of Toxoplasma gondii in raw caprine, ovine, buffalo, bovine, and camel milk using cell cultivation, cat bioassay, capture ELISA, and PCR methods in Iran.

PubMed

Dehkordi, Farhad Safarpoor; Borujeni, Mohammad Reza Haghighi; Rahimi, Ebrahim; Abdizadeh, Rahman

2013-02-01

This study was conducted to determine the presence of Toxoplasma gondii in animal milk samples in Iran. From a total of 395 dairy herds in three provinces of Iran, 66 bovine, 58 ovine, 54 caprine, 33 buffalo, and 30 camel herds were studied, and from these parts of Iran, 200 bovine, 185 ovine, 180 caprine, 164 buffalo, and 160 camel milk samples were collected from various seasons. Samples were tested for Toxoplasma gondii by cell line culture, enzyme-linked immunosorbent assay (ELISA), and polymerase chain reaction (PCR) technique. Only the results of cell line cultivation were confirmed by bioassay in cat. Results indicated that all herds were infected with Toxoplasma gondii. The culture method showed that 51 out of 889 milk samples (5.73%) were positive for Toxoplasma gondii, and all 51 positive culture results were positive with bioassay in cat. The Fars province had the highest prevalence of Toxoplasma gondii (6.84%). The ELISA test showed that 41 milk samples (4.61%) were positive for the presence of Toxoplasma gondii, while the PCR showed that 46 milk samples were positive for Toxoplasma gondii. The results showed higher sensitivity of PCR and higher specificity of ELISA. Caprine had the highest (10%) and camel had the lowest (3.12%) prevalence rate of parasite. The summer season had the highest (76.47%) but winter (3.92) had the lowest incidence of Toxoplasma gondii. This study is the first prevalence report of direct detection of Toxoplasma gondii in animal milk samples in Iran.

CXCL9 Is Important for Recruiting Immune T Cells into the Brain and Inducing an accumulation of the T Cells to the areas of tachyzoite proliferation to prevent reactivation of chronic cerebral infection with Toxoplasma gondii

USDA-ARS?s Scientific Manuscript database

T cells are required to maintain the latency of chronic infection with Toxoplasma gondii in the brain. In the present study, we examined the role of non-ELR (glutamic acid-leucine-arginine) CXC chemokine CXCL9 for T cell recruitment to prevent reactivation of infection with T. gondii. SCID mice were...

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

USDA-ARS?s Scientific Manuscript database

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...

Seroepidemiology of Toxoplasma gondii infection in human adults from three rural communities in Durango State, Mexico.

PubMed

Alvarado-Esquivel, C; Cruz-Magallanes, H M; Esquivel-Cruz, R; Estrada-Martínez, S; Rivas-González, M; Liesenfeld, O; Martínez-García, S A; Ramírez, E; Torres-Castorena, A; Castañeda, A; Dubey, J P

2008-08-01

There is scarce information concerning the epidemiology of Toxoplasma gondii infection in people of rural Mexico. Anti-T. gondii immunoglobulin (Ig)G and IgM antibodies were sought in 462 adult inhabitants from 3 rural communities of Durango, Mexico, using enzyme-linked immunoassays. In total, 110 (23.8%) of 463 persons had IgG anti-T. gondii antibodies. Ten (2.2%) of them also had IgM anti-T. gondii antibodies. Prevalences of T. gondii IgG antibodies in the 3 communities varied from 14.8 to 35.8%. The highest prevalence of infection was observed in participants older than 70 yr and in those with good housing conditions. Toxoplasma gondii infection was significantly associated with consumption of squirrel (adjusted odds ratio [OR] = 4.22; 95% confidence interval [CI] = 1.11-16.05) and turkey meat (adjusted OR = 4.58; 95% CI = 1.14-18.44). This is the first epidemiological study of T. gondii prevalence in rural Mexico.

Galectins expressed differently in genetically susceptible C57BL/6 and resistant BALB/c mice during acute ocular Toxoplasma gondii infection.

PubMed

Chen, S-J; Zhang, Y-X; Huang, S-G; Lu, F-L

2017-07-01

Ocular toxoplasmosis (OT) caused by Toxoplasma gondii is a major cause of infectious uveitis, however little is known about its immunopathological mechanism. Susceptible C57BL/6 (B6) and resistant BALB/c mice were intravitreally infected with 500 tachyzoites of the RH strain of T. gondii. B6 mice showed more severe ocular pathology and higher parasite loads in the eyes. The levels of galectin (Gal)-9 and its receptors (Tim-3 and CD137), interferon (IFN)-γ, IL-6 and IL-10 were significantly higher in the eyes of B6 mice than those of BALB/c mice; however, the levels of IFN-α and -β were significantly decreased in the eyes and CLNs of B6 mice but significantly increased in BALB/c mice after infection. After blockage of galectin-receptor interactions by α-lactose, neither ocular immunopathology nor parasite loads were different from those of infected BALB/c mice without α-lactose treatment. Although the expressions of Gal-9/receptor were significantly increased in B6 mice and Gal-1 and -3 were upregulated in both strains of mice upon ocular T. gondii infection, blockage of galectins did not change the ocular pathogenesis of genetic resistant BALB/c mice. However, IFN-α and -β were differently expressed in B6 and BALB/c mice, suggesting that type I IFNs may play a protective role in experimental OT.

Genotyping Toxoplasma gondii from wildlife in Pennsylvania and identification of natural recombinants virulent to mice.

PubMed

Dubey, J P; Van Why, K; Verma, S K; Choudhary, S; Kwok, O C H; Khan, A; Behinke, M S; Sibley, L D; Ferreira, L R; Oliveira, S; Weaver, M; Stewart, R; Su, C

2014-02-24

Recent studies indicated the predominance of Toxoplasma gondii haplogroup 12 in wildlife in the USA. However, still little is known of the genetic diversity of this parasite circulating in wildlife. In the present study, we tested coyotes (Canis latrans), red foxes (Vulpes vulpes), white-tailed deer (Odocoileus virginianus), and geese (Branta canadensis) from the state of Pennsylvania for T. gondii infection. Antibodies to T. gondii were found in 160 of 367 animals, including 92 (34.5%) of 266 coyotes, 49 (62.0%) of 79 white-tailed deer, 17 (85.0%) of 20 red fox, and two of two Canada geese tested by the modified agglutination test (cut off titer 1:25). Tissues from 105 seropositive animals were bioassayed in mice, and viable T. gondii was isolated from 29 animals, including 10 of 53 coyotes, 11 of 16 foxes, 7 of 49 deer, and one of one goose. DNA isolated from culture-derived tachyzoites of these isolates was characterized initially using multilocus PCR-RFLP markers. Nine genotypes were revealed, including ToxoDB PCR-RFLP #1 (4 isolates), #2 (2 isolates), #3 (4 isolates), #4 (6 isolates), #5 (4 isolates), #54 (1 isolate), #141 (1 isolate), #143 (1 isolate), and #216 (6 isolates), indicating high genetic diversity of T. gondii in wildlife in Pennsylvania. Pathogenicity of six T. gondii isolates (5 of #216 and #141) was determined in outbred Swiss Webster mice. Three of #216 and the #141 isolates were acute virulent to mice, and the other 2 #216 isolates were intermediate virulent. To determine the extent of genetic variation of these as well as a few recently reported virulent isolates from wildlife in North America, intron sequences were generated. Analysis of intron sequences and PCR-RFLP genotyping results indicated that the #216 isolates are likely derived from recombination of the clonal type I and III lineages. To determine if T. gondii virulence can be predicted by typing, we genotyped a collection of strains using PCR-RFLP markers for polymorphic genes ROP5

Seroepidemiology of Toxoplasma gondii infection in a mennonite community in Durango State, Mexico

USDA-ARS?s Scientific Manuscript database

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 IgG and IgM antibodies was examined in 152 Mennonites in Durango State, Mexic...

Isolation of viable Toxoplasma gondii, molecular characterization, and seroprevalence in elk (Cervus canadensis) in Pennsylvania, USA.

PubMed

Dubey, J P; Brown, J; Verma, S K; Cerqueira-Cézar, C K; Banfield, J; Kwok, O C H; Ying, Y; Murata, F H A; Pradhan, A K; Su, C

2017-08-30

Toxoplasmosis is a worldwide zoonosis. The ingestion of uncooked/undercooked meat and consumption of water contaminated with Toxoplasma gondii oocysts excreted by felids are the main modes of transmission of this parasite. T. gondii has been reported in multiple cervid species; however, little is known of the parasite in North American elk (Cervus canadensis). In the present study, antibodies to T. gondii were detected in serum of wild elk from Pennsylvania collected during 2013-2016 by the modified agglutination test (MAT, cut-off 1:25); 221 of 317 (69.7%) had MAT titers of 1:25 in 19, 1:50 in 28, 1:100 in 34, and 1:200 or higher in 140. Thus most (44.1%) elk had relatively high titers. Seroprevalence was slightly higher in males (76.9%) than females (67.5%, not statistically significant, Chi-square tests, P<0.0001) and was higher in adults (76.5%) than yearlings (46.4%, Odds ratio 3.82; 95% CL 1.72-8.47; P=0.001) or calves (21.7%, Odds ratio 12.58; 95% CL 4.51-35.10; P<0.0001). Annual seroprevalence was relatively stable throughout the period tested and ranged from 66.6% to 72.2%. Of the 101 elk harvested in 2016, hearts were bioassayed from 20 elk and tongues were bioassayed from 56; all tongue samples were negative. Viable T. gondii was isolated from hearts of two female elk, one of these was a seronegative adult and the other was a calf with no serum available for testing. Both T. gondii isolates were cultivated in cell culture and DNA derived from tachyzoites was characterized using the PCR-RFLP markers including SAG1, SAG2 (5'- 3'SAG2 and altSAG2), SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico. One isolate belongs to ToxoDB PCR-RFLP genotype #2 and the other is genotype #5. Both genotypes are frequently identified in animals in North America. Copyright © 2017. Published by Elsevier B.V.

Toxoplasma gondii Antibodies in Bulk Tank Milk Samples of Caprine Dairy Herds.

PubMed

Gazzonis, Alessia Libera; Zanzani, Sergio Aurelio; Stradiotto, Katia; Olivieri, Emanuela; Villa, Luca; Manfredi, Maria Teresa

2018-06-15

A major public health issue, Toxoplasma gondii infection can affect humans mainly via the consumption of animal products from certain species, including small ruminants. Therefore, a regular monitoring of the infection in ovine and caprine populations is advisable for the control of human and animal toxoplasmosis. Antibody detection in individual and bulk tank milk may represent a valid alternative to serological analysis, being its collection easy and not affecting animal welfare. Many serological tools for milk analysis have already been validated for several parasites, including Apicomplexa. Thus, the aim of the present study was to obtain epidemiological data on T. gondii infection through the detection of antibodies in bulk tank milk of dairy goat herds from an important area for caprine dairy production (Northern Italy). The performance of a commercial ELISA was first evaluated for analysis on caprine milk samples, using a panel of serum-milk pairs of goats naturally infected by T. gondii. The analysis on bulk tank milk confirmed the presence of antibodies anti-T. gondii in 59% of the samples. Toxoplasma gondii antibody positivity was more frequently found in farms reared under extensive (64.9%) or semi-intensive systems (68.7%) in comparison to intensive farms (51.1%). Analysis on milk revealed to be a valid alternative to serological tests, being easily applied in large-scale epidemiological surveys and for continuous monitoring of T. gondii infection.

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

PubMed

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

2018-03-01

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

BILATERAL RETINOCHOROIDITIS CAUSED BY AN ATYPICAL STRAIN OF TOXOPLASMA GONDII

PubMed Central

Bottós, Juliana; Miller, Robin H.; Belfort, Rubens N.; Macedo, Ana Carolina; Belfort, Rubens; Grigg, Michael E.

2012-01-01

Background A 53-year-old man presented with an acute bilateral posterior uveitis with extensive necrotizing retinochoroiditis but without chorioretinal scarring. A thorough workup did not reveal any underlying disease. The possibilities of atypical ocular toxoplasmosis as well as herpetic retinal necrosis were considered and specific therapy instituted, with little improvement. The patient died within two months as result of an undifferentiated squamous cell carcinoma. Methods Histopathological examination, immunohistochemistry and multi-locus polymerase chain reaction confirmed T. gondii infection of the retina Results Macroscopic examination of enucleated globe showed extensive retinal necrosis and vitreous detachment. Histological examination of retinal tissue identified numerous round–to-elliptical toxoplasmic cysts within the retina, with retinal necrosis and minimal choroidal inflammation. Immunohistochemical analyses confirmed the cysts were due to Toxoplasma gondii. DNA extracted from formalin-fixed, paraffin-embedded tissue sections was subjected to multi-locus PCR analysis at the following typing loci: SAG1, SAG2, SAG3, SAG4, B1, NTS2, GRA6, and GRA7. DNA sequencing of positive PCR products at the NTS2, SAG1, and GRA7 loci confirmed the presence of a non-archetypal strain of T. gondii infecting the eye of the patient experiencing a severe, atypical ocular toxoplasmosis Conclusion A highly divergent, non-archetypal strain of Toxoplasma gondii was responsible for causing a severe, atypical bilateral retinochoroiditis in a patient from Brazil. PMID:19666926

Detection of soluble antigens of Toxoplasma gondii by a four-layer modification of an enzyme immunoassay.

PubMed Central

Turunen, H J

1983-01-01

A sensitive four-layer modification of an enzyme immunoassay for the detection of soluble antigens of Toxoplasma gondii is described. Microtiter plates were sensitized with rabbit anti-toxoplasma immunoglobulins (6 micrograms/ml) used as the primary antibodies; guinea pig anti-toxoplasma immunoglobulins (6 micrograms/ml) were used as the secondary trapping antibodies. Horseradish peroxidase-conjugated anti-guinea pig immunoglobulins were used as the indicator antibodies. The specificity of the antigen assay was confirmed by using guinea pig immunoglobulins from preimmunization sera. The sensitivity of the antigen assay was found to be at least 10 ng of antigen protein per ml. The suitability of the method for detecting antigens of T. gondii in different specimens was studied by experimental toxoplasma infection in mice. Antigenic components of T. gondii could be detected in different tissue specimens from infected animals from the first day after infection onwards. Toxoplasma antigen in serum and urine samples from infected mice reached detectable levels on day 2 after infection followed by a linear increase in antigen concentration in succeeding samples. This method might offer a valuable aid for a rapid etiological diagnosis also in human cases of acute toxoplasmosis. PMID:6345574

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. Copyright © 2016 Elsevier Inc. All rights reserved.

Protective effect of DNA-mediated immunization with liposome-encapsulated GRA4 against infection of Toxoplasma gondii *

PubMed Central

Chen, Rui; Lu, Shao-hong; Tong, Qun-bo; Lou, Di; Shi, Dong-yan; Jia, Bing-bing; Huang, Guo-ping; Wang, Jin-fu

2009-01-01

The dense granule protein 4 (GRA4) is a granular protein from Toxoplasma gondii, and is a candidate for vaccination against this parasite. In this study, the plasmid pcDNA3.1-GRA4 (pGRA4), encoding for the GRA4 antigen, was incorporated by the dehydration-rehydration method into liposomes composed of 16 mmol/L egg phosphatidylcholine (PC), 8 mmol/L dioleoyl phosphatidylethanolamine (DOPE), and 4 mmol/L 1,2-diodeoyl-3-(trimethylammonium) propane (DOTAP). C57BL/6 mice and BALB/c mice were immunized intramuscularly three times with liposome-encapsulated pGRA4 to determine whether DNA immunization could elicit a protective immune response to T. gondii. Enzyme-linked immunosorbent assay (ELISA) of sera from immunized mice showed that liposome-encapsulated pGRA4 generated high levels of IgG antibodies to GRA4. Production of primary interferon (IFN)-γ and interleukin (IL)-2 in GRA4-stimulated splenocytes from vaccinated mice suggested a modulated Th1-type response. 72.7% of C57BL/6 mice immunized with liposome-encapsulated pGRA4 survived the challenge with 80 tissue cysts of ME49 strain, whereas C57BL/6 mice immunized with pGRA4 had only a survival rate of 54.5%. When immunized BALB/c mice were intraperitoneally challenged with 103 tachyzoites of the highly virulent RH strain, the survival time of mice immunized with liposome-encapsulated pGRA4 was markedly longer than that of other groups. Our observations show that liposome-encapsulated pGRA4 enhanced the protective effect against infection of T. gondii. PMID:19585669

Seroepidemiological study of Toxoplasma gondii infection in a population of Iranian epileptic patients.

PubMed

Babaie, Jalal; Sayyah, Mohammad; Gharagozli, Kourosh; Mostafavi, Ehsan; Golkar, Majid

2017-01-01

Epilepsy is one of the most common neurologic disorders. Underlying cause of epilepsy is unknown in 60 % of the patients. Toxoplasma gondii is an intracellular parasite which is capable of forming tissue cysts in brain of chronically infected hosts including humans. Some epidemiological studies suggested an association between toxoplasmosis and acquisition of epilepsy. In this study we determined seroprevalence of latent Toxoplasma infection in a population of Iranian epileptic patients. Participants were classified in three groups as Iranian epileptic patients (IEP, n = 414), non-epileptic patients who had other neurologic disorders (NEP, n = 150), and healthy people without any neurologic disorders (HP, n = 63). The presence of anti- Toxoplasma IgG antibodies and IgG titer in the sera were determined by ELISA method. Anti- T. gondii IgG seroprevalence obtained 35.3 %, 34.7 % and 38.1 % in IEP, NEP and HP, respectively. The seroprevalence rate was not significantly different among the three groups (P = 0.88). Anti- T. gondii IgG titer was 55.7 ± 78, 52.4 ± 74 and 69.7 ± 92 IU/ml in IEP, NEP and HP, respectively. There was not any statistically significant difference in the antibody titer between the study groups (P = 0.32). The rate of T. gondii infection in epileptic patients was not higher than non-epileptic patients and healthy people in the Iranian population.

Toxoplasma gondii infection in wild mustelids and cats across an urban-rural gradient.

PubMed

Barros, Macarena; Cabezón, Oscar; Dubey, Jitender P; Almería, Sonia; Ribas, María P; Escobar, Luis E; Ramos, Barbara; Medina-Vogel, Gonzalo

2018-01-01

The increase in human population and domestic pets, such as cats, are generating important consequences in terms of habitat loss and pathogen pollution of coastal ecosystems with potential to generate negative impacts in marine biodiversity. Toxoplasma gondii is the etiological agent of zoonotic disease toxoplasmosis, and is associated with cat abundance and anthropogenic disturbance. The presence of T. gondii oocysts in the ocean has negatively affected the health status of the threatened Southern sea otter (Enhydra lutris nereis) populations. The present study analyzed seroprevalence and presence of T. gondii DNA in American mink (Neovison vison), Southern river otters (Lontra provocax) and domestic cats (Felis silvestris catus) in four different areas in Southern Chile comprising studies in rivers and lakes in Andean foothills and mountains, marine habitat and island coastal ecosystems. Mean seroprevalence of T. gondii in the study was 64% of 151 total animals sampled: 59% of 73 American mink, 77% of 13 Southern river otters, 68% of 65 domestic cats and in two of two kodkods (Leopardus guigna). Toxoplasma gondii DNA was detected in tissues from one American mink and one Southern river otter. The present study confirms the widespread distribution of T. gondii in Southern Chile, and shows a high exposure of semiaquatic mustelids and domestic cats to the parasite. Cats and anthropogenic disturbance have a role in the maintenance of T. gondii infection in ecosystems of southern Chile.

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

USDA-ARS?s Scientific Manuscript database

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 ...

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

USDA-ARS?s Scientific Manuscript database

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...

Seroprevalence of Toxoplasma gondii Infection in Refugee and Migrant Pregnant Women along the Thailand–Myanmar Border

PubMed Central

van Enter, Bert J. D.; Lau, Yee-Ling; Ling, Clare L.; Watthanaworawit, Wanitda; Sukthana, Yaowalark; Lee, Wenn-Chyau; Nosten, François; McGready, Rose

2017-01-01

Abstract. Toxoplasma gondii primary infection in pregnancy is associated with poor obstetric outcomes. This study aimed to determine the seroprevalence of Toxoplasma infection in pregnant migrant and refugee women from Myanmar attending antenatal care in Thailand. A random selection of 199 residual blood samples from first antenatal screen in 2014–2015 was tested for Toxoplasma IgG and IgM antibodies. Seroprevalence of Toxoplasma infection was 31.7% (95% confidence interval = 25.6–38.4). Avidity testing in the three positive IgM cases indicated all were past infections. Multiparity (≥ 3 children) was significantly associated with higher Toxoplasma seropositivity rates. Seroprevalence of T. gondii infection in this pregnant population is similar to the only other report from Myanmar, where multiparity was also identified as a significant association. Toxoplasma infection is important in pregnant women. Nevertheless, in this marginalized population, this infection may be given less priority, due to resource constraints in providing the most basic components of safe motherhood programs. PMID:28719309

Metabolic Cooperation of Glucose and Glutamine Is Essential for the Lytic Cycle of Obligate Intracellular Parasite Toxoplasma gondii*

PubMed Central

Nitzsche, Richard; Zagoriy, Vyacheslav; Lucius, Richard; Gupta, Nishith

2016-01-01

Toxoplasma gondii is a widespread protozoan parasite infecting nearly all warm-blooded organisms. Asexual reproduction of the parasite within its host cells is achieved by consecutive lytic cycles, which necessitates biogenesis of significant energy and biomass. Here we show that glucose and glutamine are the two major physiologically important nutrients used for the synthesis of macromolecules (ATP, nucleic acid, proteins, and lipids) in T. gondii, and either of them is sufficient to ensure the parasite survival. The parasite can counteract genetic ablation of its glucose transporter by increasing the flux of glutamine-derived carbon through the tricarboxylic acid cycle and by concurrently activating gluconeogenesis, which guarantee a continued biogenesis of ATP and biomass for host-cell invasion and parasite replication, respectively. In accord, a pharmacological inhibition of glutaminolysis or oxidative phosphorylation arrests the lytic cycle of the glycolysis-deficient mutant, which is primarily a consequence of impaired invasion due to depletion of ATP. Unexpectedly, however, intracellular parasites continue to proliferate, albeit slower, notwithstanding a simultaneous deprivation of glucose and glutamine. A growth defect in the glycolysis-impaired mutant is caused by a compromised synthesis of lipids, which cannot be counterbalanced by glutamine but can be restored by acetate. Consistently, supplementation of parasite cultures with exogenous acetate can amend the lytic cycle of the glucose transport mutant. Such plasticity in the parasite's carbon flux enables a growth-and-survival trade-off in assorted nutrient milieus, which may underlie the promiscuous survival of T. gondii tachyzoites in diverse host cells. Our results also indicate a convergence of parasite metabolism with cancer cells. PMID:26518878

The history of Toxoplasma gondii--the first 100 years.

PubMed

Dubey, Jitender P

2008-01-01

In this paper the history of Toxoplasma gondii and toxoplasmosis is reviewed. This protozoan parasite was first discovered in 1908 and named a year later. Its medical importance remained unknown until 1939 when T. gondii was identified in tissues of a congenitally infected infant, and veterinary importance became known when it was found to cause abortion storms in sheep in 1957. The discovery of a T. gondii specific antibody test, Sabin-Feldman dye test in 1948 led to the recognition that T. gondii is a common parasite of warm-blooded hosts with a worldwide distribution. Its life cycle was not discovered until 1970 when it was found that felids are its definitive host and an environmentally resistant stage (oocyst) is excreted in feces of infected cats. The recent discovery of its common infection in certain marine wildlife (sea otters) indicates contamination of our seas with T. gondii oocysts washed from land. Hygiene remains the best preventive measure because currently there is no vaccine to prevent toxoplasmosis in humans.

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.

Risk factors for Toxoplasma gondii infection in the United States.

PubMed

Jones, Jeffrey L; Dargelas, Valerie; Roberts, Jacquelin; Press, Cindy; Remington, Jack S; Montoya, Jose G

2009-09-15

Toxoplasmosis can cause severe ocular and neurological disease. We sought to determine risk factors for Toxoplasma gondii infection in the United States. We conducted a case-control study of adults recently infected with T. gondii. Case patients were selected from the Palo Alto Medical Foundation Toxoplasma Serology Laboratory from August 2002 through May 2007; control patients were randomly selected from among T. gondii-seronegative persons. Data were obtained from serological testing and patient questionnaires. We evaluated 148 case patients with recent T. gondii infection and 413 control patients. In multivariate analysis, an elevated risk of recent T. gondii infection was associated with the following factors: eating raw ground beef (adjusted odds ratio [aOR], 6.67; 95% confidence limits [CLs], 2.09, 21.24; attributable risk [AR], 7%); eating rare lamb (aOR, 8.39; 95% CLs, 3.68, 19.16; AR, 20%); eating locally produced cured, dried, or smoked meat (aOR, 1.97; 95% CLs, 1.18, 3.28; AR, 22%); working with meat (aOR, 3.15; 95% CLs, 1.09, 9.10; AR, 5%); drinking unpasteurized goat's milk (aOR, 5.09; 95% CLs, 1.45, 17.80; AR, 4%); and having 3 or more kittens (aOR, 27.89; 95% CLs, 5.72, 135.86; AR, 10%). Eating raw oysters, clams, or mussels (aOR, 2.22; 95% CLs, 1.07, 4.61; AR, 16%) was significant in a separate model among persons asked this question. Subgroup results are also provided for women and for pregnant women. In the United States, exposure to certain raw or undercooked foods and exposure to kittens are risk factors for T. gondii infection. Knowledge of these risk factors will help to target prevention efforts.

Mechanisms and pathways of Toxoplasma gondii transepithelial migration.

PubMed

Jones, Emily J; Korcsmaros, Tamas; Carding, Simon R

2017-01-02

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.

Toxoplasma gondii strain-dependent effects on mouse behaviour.

PubMed

Kannan, Geetha; Moldovan, Krisztina; Xiao, Jian-Chun; Yolken, Robert H; Jones-Brando, Lorraine; Pletnikov, Mikhail V

2010-06-01

Toxoplasma gondii reportedly manipulates rodent behaviour to increase transmission to its definitive feline host. We compared the effects of mouse infection by two Type II strains of T. gondii, Prugniaud (PRU) and ME49, on attraction to cat odour, locomotor activity, anxiety, sensorimotor gating, and spatial working and recognition memory 2 months post-infection (mpi). Attraction to cat odour was reassessed 7 mpi. At 2 mpi, mice infected with either strain exhibited significantly more attraction to cat odour than uninfected animals did, but only PRU-infected mice exhibited this behaviour 7 mpi. PRU-infected mice had significantly greater body weights and hyperactivity, while ME49-infected mice exhibited impaired spatial working memory. No differences in parasite antibody titres were seen between PRU- and ME49-infected mice. The present data suggest the effect of T. gondii infection on mouse behaviour is parasite strain-dependent.

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

PubMed Central

Hwang, Young Sang; Shin, Ji-Hun; Yang, Jung-Pyo; Jung, Bong-Kwang; Lee, Sang Hyung; Shin, Eun-Hee

2018-01-01

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

Sporulation and survival of Toxoplasma gondii oocysts in different types of commercial cat litters

USDA-ARS?s Scientific Manuscript database

Toxoplasma gondii oocysts are environmentally resistant and can survive outdoors for months in the dry and cold climates. In the present study, sporulation and survival of T. gondii oocysts was studied in different types of cat litters commercially available in the US. Oocysts sporulated within 2-...

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

USDA-ARS?s Scientific Manuscript database

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...

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

USDA-ARS?s Scientific Manuscript database

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

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

USDA-ARS?s Scientific Manuscript database

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...

Toxoplasma gondii in sheep and goats: seroprevalence and potential risk factors under dairy husbandry practices.

PubMed

Tzanidakis, Nikolaos; Maksimov, Pavlo; Conraths, Franz J; Kiossis, Evaggelos; Brozos, Christos; Sotiraki, Smaragda; Schares, Gereon

2012-12-21

Sheep and goats are highly susceptible for infections with Toxoplasma gondii and may play a major role in the transmission of toxoplasmosis to humans. The aim of this study was to obtain up-to-date data on T. gondii infection in small ruminants and to identify putative risk factors in sheep and goats reared under dairy husbandry systems most commonly applied in Greece. To this end, ELISA tests were established for the examination of sheep and goat sera based on the use of TgSAG1, a major surface antigen of T. gondii tachyzoites. Serum samples from 2-4 years old small ruminants, 1501 from sheep and 541 from goats were examined. These samples had been collected on 69 farms in a mountainous and in a costal environment of Northern Greece from September 2008 to January 2009. In addition to farms containing only sheep (n=28) and farms containing only goats (n=9) also mixed farms with both animal species (n=32) were sampled. A standardized questionnaire was used to obtain information on putative risk factors. Sheep showed a higher seroprevalence (48.6% [729/1501]) for T. gondii than goats (30.7% [166/541]). Univariate multi-level modelling assuming random effects by the factor "farm" revealed that goats were statistically significantly less often seropositive than sheep (OR 0.475 [95% CI: 0.318-0.707]). No statistically significant regional differences in seroprevalence were observed. Risk factor analysis using univariate multi-level modelling revealed that sheep and goats that were kept under intensive (OR 4.30 [95% CI: 1.39-13.27]) or semi-intensive (OR 5.35 [95% CI: 2.33-12.28]) conditions had significantly higher odds of being seropositive. Further significant risk factors were "feeding concentrate" (OR 3.88 [95% CI: 1.81-8.29]) and providing "water from the public supply" (OR 1.67 [95% CI: 4.56-12.39]) to small ruminants. Copyright © 2012 Elsevier B.V. All rights reserved.

Phylogeography of Toxoplasma gondii points to a South American origin

USDA-ARS?s Scientific Manuscript database

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...

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...

Prevalence of Toxoplasma gondii infection in HIV-infected patients and food animals and direct genotyping of T. gondii isolates, Southern Ghana.

PubMed

Pappoe, Faustina; Cheng, Weisheng; Wang, Lin; Li, Yuanling; Obiri-Yeboah, Dorcas; Nuvor, Samuel Victor; Ambachew, Henock; Hu, Xiaodong; Luo, Qingli; Chu, Deyong; Xu, Yuanhong; Shen, Jilong

2017-06-01

Toxoplasma gondii is of public health and veterinary importance causing severe diseases in immunocompromised individuals including HIV/AIDS patients and in congenital cases and animals. There is limited information on the epidemiology of T. gondii infection in humans, particularly HIV patients and food animals and the parasite genotypes in Ghana. A total of 394 HIV-infected patients from three hospitals were screened for T. gondii anti-IgG and IgM using ELISA. DNAs from blood samples of seropositve participants and 95 brain tissues of food animals were PCR assayed to detect Toxoplasma gra6. DNA positive samples were genotyped using multilocus nested polymerase chain reaction restriction fragment length polymorphism at 10 loci: sag1, alt.sag2, sag3, btub, gra6, l358, c22-8, c29-2, pk1, and apico. The overall seroprevalence was 74.37% (293/394). Toxoplasma DNAs were detected in 3.07% of the seropositive participants and 9.47% of the animals. Six of the human DNA positive samples were partly typed at sag3: 33.33, 50, and 16.67% isolates had type I, II, and III alleles, respectively. All nine isolates from food animals typed at nine loci except apico were atypical: six isolates were identical to ToxoDB #41 and #145, and one was identical to TgCkBrRj2 all identified in Brazil. The genotype of two isolates has not been reported previously and was named as TgCtGh1. T. gondii seroprevalence is high among the HIV-infected individuals with T. gondii circulating in Ghana being genetically diverse.

Significant Reduction of Brain Cysts Caused by Toxoplasma gondii after Treatment with Spiramycin Coadministered with Metronidazole in a Mouse Model of Chronic Toxoplasmosis

PubMed Central

Chew, Wai Kit; Ambu, Stephen; Mak, Joon Wah

2012-01-01

Toxoplasma gondii is a parasite that generates latent cysts in the brain; reactivation of these cysts may lead to fatal toxoplasmic encephalitis, for which treatment remains unsuccessful. We assessed spiramycin pharmacokinetics coadministered with metronidazole, the eradication of brain cysts and the in vitro reactivation. Male BALB/c mice were fed 1,000 tachyzoites orally to develop chronic toxoplasmosis. Four weeks later, infected mice underwent different treatments: (i) infected untreated mice (n = 9), which received vehicle only; (ii) a spiramycin-only group (n = 9), 400 mg/kg daily for 7 days; (iii) a metronidazole-only group (n = 9), 500 mg/kg daily for 7 days; and (iv) a combination group (n = 9), which received both spiramycin (400 mg/kg) and metronidazole (500 mg/kg) daily for 7 days. An uninfected control group (n = 10) was administered vehicle only. After treatment, the brain cysts were counted, brain homogenates were cultured in confluent Vero cells, and cysts and tachyzoites were counted after 1 week. Separately, pharmacokinetic profiles (plasma and brain) were assessed after a single dose of spiramycin (400 mg/kg), metronidazole (500 mg/kg), or both. Metronidazole treatment increased the brain spiramycin area under the concentration-time curve from 0 h to ∞ (AUC0–∞) by 67% without affecting its plasma disposition. Metronidazole plasma and brain AUC0–∞ values were reduced 9 and 62%, respectively, after spiramycin coadministration. Enhanced spiramycin brain exposure after coadministration reduced brain cysts 15-fold (79 ± 23 for the combination treatment versus 1,198 ± 153 for the untreated control group [P < 0.05]) and 10-fold versus the spiramycin-only group (768 ± 125). Metronidazole alone showed no effect (1,028 ± 149). Tachyzoites were absent in the brain. Spiramycin reduced in vitro reactivation. Metronidazole increased spiramycin brain penetration, causing a significant reduction of T. gondii brain cysts, with potential clinical

High prevalence of anti-toxoplasma antibodies and absence of Toxoplasma gondii infection risk factors among pregnant women attending routine antenatal care in two Hospitals of Addis Ababa, Ethiopia.

PubMed

Gelaye, Woyneshet; Kebede, Tadesse; Hailu, Asrat

2015-05-01

Toxoplasmosis is an infection caused by the protozoan parasite Toxoplasma gondii. It is acquired mainly by eating raw or undercooked meat containing Toxoplasma gondii tissue cyst, eating food or water contaminated with oocyst, and acquiring congenital infection through the placenta. This study was conducted to determine the prevalence of toxoplasmosis and assess possible risk factors associated with the infection among pregnant women in Addis Ababa, Ethiopia. Cross sectional study was designed, and 288 serum samples were collected from November 1(st) 2010 to January 2011. The serum samples were tested for anti- Toxoplasma gondii antibodies using latex agglutination test. The risk factors were tested for significance using Bivariate and multivariate analysis. P-value <0.05 was considered statistically significant. 85.4% were positive for anti Toxoplasma gondii antibody. No significant association was observed between seroprevalence and age, gestational age, socio demographic characters, history of abortion, consumption of raw or undercooked meat, consumption of raw vegetable, owning of cat, and blood transfusion. Prevalence of toxoplasmosis among pregnant women in Addis Ababa, Ethiopia is higher than that reported from other countries. Efforts to describe risk factors for toxoplasma infection among Ethiopians should focus in children. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Screening for small molecule inhibitors of Toxoplasma gondii.

PubMed

Kortagere, Sandhya

2012-12-01

Toxoplasma gondii, the agent that causes toxoplasmosis, is an opportunistic parasite that infects many mammalian species. It is an obligate intracellular parasite that causes severe congenital neurological and ocular disease mostly in immunocompromised humans. The current regimen of therapy includes only a few medications that often lead to hypersensitivity and toxicity. In addition, there are no vaccines available to prevent the transmission of this agent. Therefore, safer and more effective medicines to treat toxoplasmosis are urgently needed. The author presents in silico and in vitro strategies that are currently used to screen for novel targets and unique chemotypes against T. gondii. Furthermore, this review highlights the screening technologies and characterization of some novel targets and new chemical entities that could be developed into highly efficacious treatments for toxoplasmosis. A number of diverse methods are being used to design inhibitors against T. gondii. These include ligand-based methods, in which drugs that have been shown to be efficacious against other Apicomplexa parasites can be repurposed to identify lead molecules against T. gondii. In addition, structure-based methods use currently available repertoire of structural information in various databases to rationally design small-molecule inhibitors of T. gondii. Whereas the screening methods have their advantages and limitations, a combination of methods is ideally suited to design small-molecule inhibitors of complex parasites such as T. gondii.

Toxoplasma gondii dissemination: a parasite's journey through the infected host.

PubMed

Harker, K S; Ueno, N; Lodoen, M B

2015-03-01

Toxoplasma gondii is a highly successful global pathogen that is remarkable in its ability to infect nearly any nucleated cell in any warm-blooded animal. Infection with T. gondii typically occurs through the ingestion of contaminated food or water, but the parasite then breaches the intestinal epithelial barrier and spreads from the lamina propria to a large variety of other organs in the body. A key feature of T. gondii pathogenesis is the parasite's ability to cross formidable biological barriers in the infected host and enter tissues such as the brain, eye and placenta. The dissemination of T. gondii into these organs underlies the severe disease that accompanies human toxoplasmosis. In this review, we will focus on seminal studies as well as exciting recent findings that have shaped our current understanding of the cellular and molecular mechanisms by which T. gondii journeys throughout the host and enters organs to cause disease. © 2014 John Wiley & Sons Ltd.

Toxoplasma gondii Infection in Kyrgyzstan: Seroprevalence, Risk Factor Analysis, and Estimate of Congenital and AIDS-Related Toxoplasmosis

PubMed Central

Bodosheva, Aigerim; Kuttubaev, Omurbek; Hehl, Adrian B.; Tanner, Isabelle; Ziadinov, Iskender; Torgerson, Paul R.; Deplazes, Peter

2013-01-01

Background HIV-prevalence, as well as incidence of zoonotic parasitic diseases like cystic echinococcosis, has increased in the Kyrgyz Republic due to fundamental socio-economic changes after the breakdown of the Soviet Union. The possible impact on morbidity and mortality caused by Toxoplasma gondii infection in congenital toxoplasmosis or as an opportunistic infection in the emerging AIDS pandemic has not been reported from Kyrgyzstan. Methodology/Principal Findings We screened 1,061 rural and 899 urban people to determine the seroprevalence of T. gondii infection in 2 representative but epidemiologically distinct populations in Kyrgyzstan. The rural population was from a typical agricultural district where sheep husbandry is a major occupation. The urban population was selected in collaboration with several diagnostic laboratories in Bishkek, the largest city in Kyrgyzstan. We designed a questionnaire that was used on all rural subjects so a risk-factor analysis could be undertaken. The samples from the urban population were anonymous and only data with regard to age and gender was available. Estimates of putative cases of congenital and AIDS-related toxoplasmosis in the whole country were made from the results of the serology. Specific antibodies (IgG) against Triton X-100 extracted antigens of T. gondii tachyzoites from in vitro cultures were determined by ELISA. Overall seroprevalence of infection with T. gondii in people living in rural vs. urban areas was 6.2% (95%CI: 4.8–7.8) (adjusted seroprevalence based on census figures 5.1%, 95% CI 3.9–6.5), and 19.0% (95%CI: 16.5–21.7) (adjusted 16.4%, 95% CI 14.1–19.3), respectively, without significant gender-specific differences. The seroprevalence increased with age. Independently low social status increased the risk of Toxoplasma seropositivity while increasing numbers of sheep owned decreased the risk of seropositivity. Water supply, consumption of unpasteurized milk products or undercooked meat, as

Toxoplasma gondii and Epilepsy.

PubMed

Ayaz, Erol; Türkoğlu, Şule Aydın; Orallar, Hayriye

2016-06-01

Toxoplasma gondii is a zoonotic parasite can be seen in all the vital organ; in the acute phase, it can be found in the blood, cerebrospinal fluid, semen, tears, saliva, urine, and in almost all body fluids. Transplasental infection can lead to fetal damage and miscarriage. Its last hosts are felines and intermediate hosts are all mammals, including humans. People infected by the ingestion of meat containing cysts in undercooked or raw, are thrown oocysts with cat felines By taking in water and food, from mother to fetus transplacental way, the infected organ transplantation, blood transfusion, laboratory accidents and kaprofaj transmitted by mechanical vectors of the invertebrates. Suppression of the immune system is being transformed to the shape and texture of the cysts with bradyzoite. The parasite settles in the cells of the tissue cysts and causes change in the cellular mechanisms, such as cytokinin task. Depending on changes and type of neurotransmitter (GABA, glutamate, serotonin, dopamine) levels in CSF in ions (Ca, K, Cl, Mg), it is believed that there is a change in their concentration. In this review, literature about the relationship between T. gondii and epilepsy and epileptiform activity the importance of parasites, which settle in the brain, will be highlighted.

Seroprevalence of Toxoplasma gondii in wild kangaroos using an ELISA

PubMed Central

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

2009-01-01

Infection with Toxoplasma gondii is a significant problem in Australian marsupials, and can lead to devastating disease and predispose animals to predation. T. gondii infection in kangaroos is also of public health significance due to the kangaroo meat trade. A moderate seroprevalence of T. gondii was observed in a study of western grey kangaroos located in the Perth metropolitan area in Western Australia. Of 219 kangaroos tested, 15.5% (95%CI: 10.7-20.3) were positive for T. gondii antibodies using an ELISA developed to detect T. gondii IgG in macropod marsupials. When compared with the commercially available MAT (modified agglutination test), the ELISA developed was in absolute agreement and yielded a κ coefficient of 1.00. Of 18 kangaroos tested for the presence of T. gondii DNA by PCR, the 9 ELISA positive kangaroos tested PCR positive and the 9 ELISA negative kangaroos tested PCR negative indicating the ELISA protocol was both highly specific and sensitive and correlated 100% with the more labour intensive PCR assay. PMID:19567231

Toxoplasma gondii as a parasite in food: analysis and control

USDA-ARS?s Scientific Manuscript database

Toxoplasmosis, caused by Toxoplasma gondii, is one of the most common parasitic infections of humans and other warmblooded animals. Nearly one third of humans have been exposed to the parasite. Congenital infection occurs when a woman becomes infected during pregnancy and transmits the parasite to t...

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

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. Copyright © 2014 Elsevier B.V. All rights reserved.

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

USDA-ARS?s Scientific Manuscript database

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...

Global Analysis of Palmitoylated Proteins in Toxoplasma gondii.

PubMed

Foe, Ian T; Child, Matthew A; Majmudar, Jaimeen D; Krishnamurthy, Shruthi; van der Linden, Wouter A; Ward, Gary E; Martin, Brent R; Bogyo, Matthew

2015-10-14

Post-translational modifications (PTMs) such as palmitoylation are critical for the lytic cycle of the protozoan parasite Toxoplasma gondii. While palmitoylation is involved in invasion, motility, and cell morphology, the proteins that utilize this PTM remain largely unknown. Using a chemical proteomic approach, we report a comprehensive analysis of palmitoylated proteins in T. gondii, identifying a total of 282 proteins, including cytosolic, membrane-associated, and transmembrane proteins. From this large set of palmitoylated targets, we validate palmitoylation of proteins involved in motility (myosin light chain 1, myosin A), cell morphology (PhIL1), and host cell invasion (apical membrane antigen 1, AMA1). Further studies reveal that blocking AMA1 palmitoylation enhances the release of AMA1 and other invasion-related proteins from apical secretory organelles, suggesting a previously unrecognized role for AMA1. These findings suggest that palmitoylation is ubiquitous throughout the T. gondii proteome and reveal insights into the biology of this important human pathogen. Copyright © 2015 Elsevier Inc. All rights reserved.

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. PMID:28452683

Molecular diagnosis of Toxoplasma gondii infection in Libya.

PubMed

Gashout, Aisha; Amro, Ahmad; Erhuma, Mabruk; Al-Dwibe, Hamida; Elmaihub, Eanas; Babba, Hamouda; Nattah, Nabil; Abudher, Abdalhafid

2016-04-16

Toxoplasma gondii infections are prevalent in humans and animals throughout Libya. Current diagnosis is based on detection of Toxoplasma-specific IgM and IgG. In this study, we established and optimized a diagnostic PCR assay for molecular diagnosis of T. gondii in Libya. From January to December, 2010, 177 blood and serum samples were collected from suspected patients. This includes: 140 women who have had spontaneous abortions, 26 HIV-positive patients, nine patients with leukemia and lymphoma, and two infants with ocular infection. Samples were screened for anti-Toxoplasma IgG and IgM antibodies before DNA extraction. The surface antigen gene 2 (SAG2) was targeted in a semi-nested PCR to amplify a 999 bp and a 614 bp fragment in the first and the second run respectively. A total of 54/140 (38.5 %) women who have had spontaneous abortions, 23/26 (88 %) HIV patients, 6/9 (66.6 %) of the leukaemia and lymphoma patients, and one child with ocular infection were seropositive for anti-Toxoplasma IgG and/or IgM. Genomic DNA was extracted from 38 selected seropositive samples. The PCR was sensitive enough to detect DNA concentration of 12 ng/μL. PCR analysis was performed for 38 selected seropositive patients (16 women who have had spontaneous abortions, 15 positive HIV patients, six leukaemia patients and one child with ocular infection). Our designed primers were successfully amplified in 22/38 (57.9 %) samples; 5/12 (35.7 %) from serum and 17/26 (65.8 %) from whole blood samples. All PCR positive samples were IgG-positive except two samples which were IgM and IgG & IgM-positive serum samples respectively. The semi-nested PCR confirmed five more samples. These included two leukaemia and two HIV-positive whole blood samples and one serum sample from an aborted woman. The ability of PCR to diagnose active toxoplasmosis is needed in immunocompromised patients and congenital toxoplasmosis cases, especially when serological techniques fail. For the first time in

Seroprevalence of Toxoplasma gondii in seabirds from Abrolhos Archipelago, Brazil

USDA-ARS?s Scientific Manuscript database

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...

EFFECTS OF HIGH PRESSURE PROCESSING ON TOXOPLASMA GONDII OOCYSTS ON RASPBERRIES

USDA-ARS?s Scientific Manuscript database

Oocysts of Toxoplasma gondii are environmentally resistant stages. Humans can become infected by accidentally ingesting the oocysts in water or on contaminated produce. Severe disease can occur in immunocompromised individuals and non-immune pregnant women can infect their offspring. Chronic infect...

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

USDA-ARS?s Scientific Manuscript database

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...

Functional analysis of rhomboid proteases during Toxoplasma invasion.

PubMed

Shen, Bang; Buguliskis, Jeffrey S; Lee, Tobie D; Sibley, L David

2014-10-21

Host cell invasion by Toxoplasma gondii and other apicomplexan parasites requires transmembrane adhesins that mediate binding to receptors on the substrate and host cell to facilitate motility and invasion. Rhomboid proteases (ROMs) are thought to cleave adhesins within their transmembrane segments, thus allowing the parasite to disengage from receptors and completely enter the host cell. To examine the specific roles of individual ROMs during invasion, we generated single, double, and triple knockouts for the three ROMs expressed in T. gondii tachyzoites. Analysis of these mutants demonstrated that ROM4 is the primary protease involved in adhesin processing and host cell invasion, whereas ROM1 or ROM5 plays negligible roles in these processes. Deletion of ROM4 blocked the shedding of adhesins such as MIC2 (microneme protein 2), causing them to accumulate on the surface of extracellular parasites. Increased surface adhesins led to nonproductive attachment, altered gliding motility, impaired moving junction formation, and reduced invasion efficiency. Despite the importance of ROM4 for efficient invasion, mutants lacking all three ROMs were viable and MIC2 was still efficiently removed from the surface of invaded mutant parasites, implying the existence of ROM-independent mechanisms for adhesin removal during invasion. Collectively, these results suggest that although ROM processing of adhesins is not absolutely essential, it is important for efficient host cell invasion by T. gondii. Importance: Apicomplexan parasites such as Toxoplasma gondii express surface proteins that bind host cell receptors to aid invasion. Many of these adhesins are subject to cleavage by rhomboid proteases (ROMs) within their transmembrane segments during invasion. Previous studies have demonstrated the importance of adhesin cleavage for parasite invasion and proposed that the ROMs responsible for processing would be essential for parasite survival. In T. gondii, ROM5 was thought to be the

Disseminated toxoplasmosis in black-footed penguins (Spheniscus demersus).

PubMed

Ploeg, Margreet; Ultee, Ton; Kik, Marja

2011-12-01

Three 1- to 3-mo-old black-footed penguins (Spheniscus Demersus) died within 24 hr of showing central nervous signs such as ataxia. The birds were housed in a baby penguin crèche. At necropsy, peritonitis, pneumonia, hepatomegaly, splenomegaly, and renomegaly were evident. Histologically, the liver, lung, brain, and small intestine contained numerous tachyzoites and a few cysts of Toxoplasma. Immunohistochemistry identified the protozoal parasites as Toxoplasma gondii. Ultrastructurally, this was confirmed by the presence of many tachyzoites of T. gondii in the liver and lungs.

Shedding of Toxoplasma gondii oocysts by Felidae in zoos in the Czech Republic.

PubMed

Lukesová, D; Literák, I

1998-01-15

In 1995 and 1996, the shedding of Toxoplasma gondii oocysts was monitored in the faeces of Felidae in six zoos in the Czech Republic. In all, 2287 samples of faeces from 19 species of Felidae were examined. In Ostrava Zoo, four episodes of shedding of Toxoplasma-like oocysts were identified, using a flotation examination, in a pair of wild cats (Felis silvestris), six episodes in a wild cat held separately, and three episodes in a pair of Amur leopard cats (F. euptilurus). After the passage of sporulated oocysts through laboratory mice, T. gondii was confirmed in the pair of wild cats (three episodes), in the wild cat held separately (three episodes) and in the pair of Amur leopard cats (one episode). In Jihlava Zoo, one episode of shedding of T. gondii oocyst was identified in Geoffroy's cat (Oncifelis geoffroyi) using flotation and isolation examination. The possible sources of toxoplasmosis of the Felidae in zoos are discussed.

High seroprevalence of Toxoplasma gondii infection in a subset of Mexican patients with work accidents and low socioeconomic status.

PubMed

Alvarado-Esquivel, Cosme; Torres-Castorena, Alejandro; Liesenfeld, Oliver; Estrada-Martínez, Sergio; Urbina-Álvarez, Jesús D

2012-01-11

Toxoplasma gondii has been associated with reflex impairment and traffic accidents. It is unknown whether Toxoplasma infection might be associated with work accidents. Therefore, using a case-control seroprevalence study design, 133 patients with a recent work accident and 266 control subjects of the general population from the same region were examined with enzyme-linked immunoassays for the presence and levels of anti-Toxoplasma IgG antibodies and anti-Toxoplasma IgM antibodies. Socio-demographic, work, clinical and behavioral characteristics from each worker were obtained. Eleven (8.3%) of 133 patients, and 14 (5.3%) of 266 controls had anti-T. gondii IgG antibodies. Anti-T. gondii IgG levels were higher than 150 IU/ml in 8 (6%) patients and 10 (3.8%) controls. Anti-T. gondii IgM antibodies were found in one (0.8%) of the workers, and in 6 (2.3%) of the controls. No statistically significant differences in the IgG seroprevalences, frequencies of high IgG levels, and IgM seroprevalences among patients and controls were found. In contrast, a low socio-economic level in patients with work accidents was associated with Toxoplasma seropositivity (P = 0.01). Patients with work accidents and low socioeconomic status showed a significantly (OR = 3.38; 95% CI: 0.84-16.06; P = 0.04) higher seroprevalence of T. gondii infection than controls of the same socioeconomic status (15.1% vs. 5%, respectively). Multivariate analysis showed a positive association of T. gondii infection with boar meat consumption (OR = 3.04; 95% CI: 1.03-8.94; P = 0.04). In contrast, a negative association between T. gondii infection and national trips (OR = 0.40; 95% CI: 0.17-0.96; P = 0.04), sausage consumption (OR = 0.20; 95% CI: 0.05-0.68; P = 0.01), and ham consumption (OR = 0.16; 95% CI: 0.05-0.51; P = 0.002) was found. In the study described here seropositivity to T. gondii was associated to work accidents in a subset of patients with low socioeconomic status. This is the first report of an

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

USDA-ARS?s Scientific Manuscript database

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...

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

USDA-ARS?s Scientific Manuscript database

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 ...

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

USDA-ARS?s Scientific Manuscript database

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...

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...

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

USDA-ARS?s Scientific Manuscript database

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 ...

Toxoplasma gondii Recombinant Antigens as Tools for Serodiagnosis of Human Toxoplasmosis: Current Status of Studies

PubMed Central

2013-01-01

Toxoplasma gondii is a parasitic protozoan which is the cause of toxoplasmosis. Although human toxoplasmosis in healthy adults is usually asymptomatic, serious disease can occur in the case of congenital infections and immunocompromised individuals. Furthermore, despite the exact recognition of its etiology, it still presents a diagnostic problem. Diagnosis of toxoplasmosis is mainly based on the results of serological tests detecting anti-T. gondii-specific antibodies in the patient's serum sample. The specificities and sensitivities of serology tests depend mostly on the diagnostic antigen(s) used. Most of the commercial serological kits currently available are based on Toxoplasma lysate antigens (TLAs). In recent years, many studies showed that recombinant antigenic proteins of T. gondii may be an alternative source of antigens which are very useful for the serodiagnosis of toxoplasmosis. This article presents a review of current studies on the application and usefulness of different T. gondii recombinant antigens in serological tests for the diagnosis of human toxoplasmosis. PMID:23784855

Toxoplasmosis in sand fox (Vulpes rueppelli).

PubMed

Pas, An; Dubey, J P

2008-08-01

Fatal toxoplasmosis was diagnosed in a sand fox (Vulpes rueppelli) from United Arab Emirates. Toxoplasma gondii-like tachyzoites were found associated with necrosis in the intestine, spleen, liver, pancreas, lungs, mesenteric lymph nodes, and heart. Tachyzoites reacted positively with T. gondii-specific polyclonal antibodies. Antibodies to T. gondii were detected in 8 captive V. rueppelli assayed by the modified direct agglutination test in titers of 1:800 or higher.

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'.

Seroprevalence of Toxoplasma gondii in southern districts of Tamil Nadu using IgG-ELISA.

PubMed

Sucilathangam, G; Palaniappan, N; Sreekumar, C; Anna, T

2012-10-01

The present study was conducted to assess the seroprevalence of Toxoplasma gondii in and around Tirunelveli by in-house IgG assay using ELISA. Serum samples from 175 immunodeficient and 175 immunocompetent patients were collected at Tirunelveli district, Tamil Nadu from May 2006 to October 2007. They were subjected into in-house IgG assay using enzyme-linked immune sorbent assay (ELISA) in which tachyzoite soluble antigen derived from solubilised whole organisms was used. Out of 350 patients tested by IgG ELISA, 46 patients (13.14%) had antibodies for toxoplasmosis with mean OD value of 0.2 ± 0.073 and the OD value ranged from 0.144 to 0.444. Among the immunocompetent group of 175 patients, 19 patients (10.86%) had antibodies to toxoplasmosis whereas, in immunodeficient group of 175 patients, 27 patients (15.43%) had antibodies for toxoplasmosis. There was no statistical difference (P > 0.05) between the immunocompetent and immunodeficient group. The sensitivity and specificity of IgG ELISA in detecting toxoplasmosis was 90 and 100%, respectively. The overall seroprevalence of toxoplasmosis in and around Tirunelveli district of Tamil Nadu was 13.14% based on IgG ELISA. The study has proved ELISA to be a sensitive and specific procedure for the serodiagnosis of toxoplasmosis.

Protective mucosal Th2 immune response against Toxoplasma gondii by murine mesenteric lymph node dendritic cells.

PubMed

Dimier-Poisson, Isabelle; Aline, Fleur; Mévélec, Marie-Noëlle; Beauvillain, Céline; Buzoni-Gatel, Dominique; Bout, Daniel

2003-09-01

Toxoplasma gondii, an obligate intracellular parasite pathogen which initially invades the intestinal epithelium before disseminating throughout the body, may cause severe sequelae in fetuses and life-threatening neuropathy in immunocompromised patients. Immune protection is usually thought to be performed through a systemic Th1 response; considering the route of parasite entry it is important to study and characterize the local mucosal immune response to T. gondii. Despite considerable effort, Toxoplasma-targeted vaccines have proven to be elusive using conventional strategies. We report the use of mesenteric lymph node dendritic cells (MLNDCs) pulsed ex vivo with T. gondii antigens (TAg) as a novel investigation approach to vaccination against T. gondii-driven pathogenic processes. Using a murine model, we demonstrate in two genetically distinct mouse strains (C57BL/6 and CBA/J) that adoptively transferred TAg-pulsed MLNDCs elicit a mucosal Toxoplasma-specific Th2-biased immune response in vivo and confer strong protection against infection. We also observe that MLNDCs mostly traffic to the intestine where they enhance resistance by reduction in the mortality and in the number of brain cysts. Thus, ex vivo TAg-pulsed MLNDCs represent a powerful tool for the study of protective immunity to T. gondii, delivered through its natural route of entry. These findings might impact the design of vaccine strategies against other invasive microorganisms known to be delivered through digestive tract.

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.

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

USDA-ARS?s Scientific Manuscript database

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...

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.

Metabolic Cooperation of Glucose and Glutamine Is Essential for the Lytic Cycle of Obligate Intracellular Parasite Toxoplasma gondii.

PubMed

Nitzsche, Richard; Zagoriy, Vyacheslav; Lucius, Richard; Gupta, Nishith

2016-01-01

Toxoplasma gondii is a widespread protozoan parasite infecting nearly all warm-blooded organisms. Asexual reproduction of the parasite within its host cells is achieved by consecutive lytic cycles, which necessitates biogenesis of significant energy and biomass. Here we show that glucose and glutamine are the two major physiologically important nutrients used for the synthesis of macromolecules (ATP, nucleic acid, proteins, and lipids) in T. gondii, and either of them is sufficient to ensure the parasite survival. The parasite can counteract genetic ablation of its glucose transporter by increasing the flux of glutamine-derived carbon through the tricarboxylic acid cycle and by concurrently activating gluconeogenesis, which guarantee a continued biogenesis of ATP and biomass for host-cell invasion and parasite replication, respectively. In accord, a pharmacological inhibition of glutaminolysis or oxidative phosphorylation arrests the lytic cycle of the glycolysis-deficient mutant, which is primarily a consequence of impaired invasion due to depletion of ATP. Unexpectedly, however, intracellular parasites continue to proliferate, albeit slower, notwithstanding a simultaneous deprivation of glucose and glutamine. A growth defect in the glycolysis-impaired mutant is caused by a compromised synthesis of lipids, which cannot be counterbalanced by glutamine but can be restored by acetate. Consistently, supplementation of parasite cultures with exogenous acetate can amend the lytic cycle of the glucose transport mutant. Such plasticity in the parasite's carbon flux enables a growth-and-survival trade-off in assorted nutrient milieus, which may underlie the promiscuous survival of T. gondii tachyzoites in diverse host cells. Our results also indicate a convergence of parasite metabolism with cancer cells. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Carbohydrate Metabolism in the Toxoplasma gondii Apicoplast: Localization of Three Glycolytic Isoenzymes, the Single Pyruvate Dehydrogenase Complex, and a Plastid Phosphate Translocator▿ †

PubMed Central

Fleige, Tobias; Fischer, Karsten; Ferguson, David J. P.; Gross, Uwe; Bohne, Wolfgang

2007-01-01

Many apicomplexan parasites, such as Toxoplasma gondii and Plasmodium species, possess a nonphotosynthetic plastid, referred to as the apicoplast, which is essential for the parasites’ viability and displays characteristics similar to those of nongreen plastids in plants. In this study, we localized several key enzymes of the carbohydrate metabolism of T. gondii to either the apicoplast or the cytosol by engineering parasites which express epitope-tagged fusion proteins. The cytosol contains a complete set of enzymes for glycolysis, which should enable the parasite to metabolize imported glucose into pyruvate. All the glycolytic enzymes, from phosphofructokinase up to pyruvate kinase, are present in the T. gondii genome, as duplicates and isoforms of triose phosphate isomerase, phosphoglycerate kinase, and pyruvate kinase were found to localize to the apicoplast. The mRNA expression levels of all genes with glycolytic products were compared between tachyzoites and bradyzoites; however, a strict bradyzoite-specific expression pattern was observed only for enolase I. The T. gondii genome encodes a single pyruvate dehydrogenase complex, which was located in the apicoplast and absent in the mitochondrion, as shown by targeting of epitope-tagged fusion proteins and by immunolocalization of the native pyruvate dehydrogenase complex. The exchange of metabolites between the cytosol and the apicoplast is likely to be mediated by a phosphate translocator which was localized to the apicoplast. Based on these localization studies, a model is proposed that explains the supply of the apicoplast with ATP and the reduction power, as well as the exchange of metabolites between the cytosol and the apicoplast. PMID:17449654

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

USDA-ARS?s Scientific Manuscript database

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...

Risk factors associated with Toxoplasma gondii infection in captive Sapajus spp

USDA-ARS?s Scientific Manuscript database

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 ...

Toxoplasma gondii in horse meat intended for human consumption in Romania

USDA-ARS?s Scientific Manuscript database

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...

Atypical Strain of Toxoplasma gondii Causing Fatal Reactivation after Hematopoietic Stem Cell Transplantion in a Patient with an Underlying Immunological Deficiency

PubMed Central

Štajner, Tijana; Vasiljević, Zorica; Vujić, Dragana; Marković, Marija; Ristić, Goran; Mićić, Dragan; Pašić, Srdjan; Ivović, Vladimir; Ajzenberg, Daniel

2013-01-01

In immunocompromized patients, including hematopoietic stem cell transplant (HSCT) recipients, life-threatening toxoplasmosis may result from reactivation of previous infection. We report a case of severe disseminated toxoplasmosis that developed early after allogeneic HSCT for T-cell lymphoblastic leukemia/lymphoma in a 15-year-old Toxoplasma gondii-seropositive boy with Nijmegen breakage syndrome, a rare genetic DNA repair disorder associated with immunodeficiency. The donor was the patient's HLA-identical brother. Prophylaxis with cotrimoxazole was discontinued a day before the HSCT procedure. Signs of lung infection appeared as early as day 14 post-HSCT. The presence of tachyzoite-like structures on Giemsa-stained bronchoalveolar lavage (BAL) fluid smears suggested toxoplasmosis. Real-time PCR targeted at the T. gondii AF146527 gene revealed extremely high parasite burdens in both blood and BAL fluid. Although immediate introduction of specific treatment resulted in a marked reduction of the parasite load and transient clinical improvement, the patient deteriorated and died of multiple organ failure on day 39 post-HSCT. Direct genotyping of T. gondii DNA from blood and BAL fluid with the PCR-restriction fragment length polymorphism method revealed type II alleles with SAG1, SAG2, and GRA6 markers but alleles of both type I and type II with GRA7. Additional analysis with 15 microsatellite markers showed that the T. gondii DNA was atypical and genetically divergent from that of the clonal type I, II, and III strains. This is the first report of increased clinical severity of toxoplasmosis associated with an atypical strain in the setting of immunosuppression, which emphasizes the need to diagnose and monitor toxoplasmosis by quantitative molecular methods in cases of reactivation risk. PMID:23761151

[Detection of Toxoplasma gondii DNA in human lymph node tissue by in situ hybridization].

PubMed

Liu, C; Ke, O; Tan, D; Zhang, Z

1998-01-01

To detect the presence of Toxoplasma gondii in lymph node tissue in patients with Toxoplasma infection. T. gondii (RH strain) specific DNA fragment clones were obtained by using PCR and gene recombination technique. The DNA fragments used as hybridization probes were labelled with digoxigenin by random primer method. The technique of in situ hybridization (ISH) was used to detect T. g DNA in the lymph node sections. Four out of 120 samples T. g DNA were found positive, one with Hodgkin's disease (HD) (1/32), one with non-Hodgkin's lymphoma (NHL) (1/41) and 2 with chronic lymphadenitis (CL) (2/47). The total positive rate was 3.3%. It was demonstrated that this highly specific probe could detect 10 pg of the total RH strain T. g DNA. ISH was applicable in detecting pathogens in the lymph node tissues of individuals with Toxoplasma infection.

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.

Re-infection of Toxoplasma gondii after HSCT presenting lymphadenopathy resembling recurrence of lymphoma.

PubMed

Hashiguchi, Junichi; Onozawa, Masahiro; Naka, Tomoaki; Hatanaka, Kanako C; Shiratori, Souichi; Sugita, Junichi; Fujimoto, Katsuya; Matsuno, Yoshihiro; Teshima, Takanori

2018-06-01

Toxoplasma gondii (T. gondii) reactivation is one of the fatal complications after hematopoietic stem cell transplantation (HSCT); however, re-infection has not been reported. Here, we report a case of mycosis fungoides in which cervical lymphadenopathy developed after HSCT. Initially, recurrent lymphoma was suspected. However, biopsy of the lymph node showed typical histology of toxoplasmosis and serology showed re-infection of T. gondii. Toxoplasmosis needs to be differentiated for cases with lymphoadenopthy after HSCT. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

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

Prevalence of Toxoplasma gondii and Toxocara canis among Patients with Uveitis.

PubMed

Lim, Su Jin; Lee, Sang Eun; Kim, Sun Hyun; Hong, Sung-Hee; You, Yong Sung; Kwon, Oh Woong; Kim, Hyeun Seung

2015-04-01

To investigate the prevalence of Toxoplasma gondii and Toxocara canis in patients with uveitis. Patients with uveitis were examined. Serum antibodies to T. gondii and T. canis were tested by using the enzyme-linked immunosorbent assay. Polymerase chain reaction (PCR) was done using blood and aqueous humor (AH). Ninety-eight patients were enrolled. Mean age was 43.5 ± 13.2 years. Six patients were seropositive for T. gondii with the following pattern: anterior uveitis, 1; posterior uveitis with retinitis, 2; pan uveitis, 2. One patient had a positive PCR result for T. gondii in AH, who showed panuveitis. Twenty-three patients were positive to serum IgG for T. canis with the following clinical manifestation: granuloma, 6; pigmented scar, 3; vitritis, 6--but none were PCR positive. T. gondii and T. canis are still important causes of uveitis. Ocular toxocariasis is not an uncommon cause of uveitis, even in adults.

Prevalence of Toxoplasma gondii and Toxocara canis among patients with uveitis.

PubMed

Lim, Su Jin; Lee, Sang Eun; Kim, Sun Hyun; Hong, Sung-Hee; You, Yong Sung; Kwon, Oh Woong; Kim, Hyeun Seung

2014-10-01

To investigate the prevalence of Toxoplasma gondii and Toxocara canis in patients with uveitis. Patients with uveitis were examined. Serum antibodies to T. gondii and T. canis were tested by using enzyme-linked immunosorbent assay (ELISA). Polymerase chain reaction (PCR) was done using blood and aqueous humor (AH). 98 patients were enrolled. Mean age was 43.5 ± 13.2 years. Six patients were seropositive for T. gondii with the following pattern-anterior uveitis: 1; posterior uveitis with retinitis: 2; pan uveitis: 2. One patient had a positive result of PCR for T.gondii in AH, who showed pan uveitis. 23 patients were positive to serum IgG for T. canis with the following clinical manifestation-granuloma: 6; pigmented scar: 3; virtrits: 6-but none were PCR positive. T.gondii and T.canis are still one of the important causes of uveitis. Ocular toxocariasis is not an uncommon cause of uveitis even in adult.

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.

Isolation and Genotyping of Toxoplasma gondii in Brazilian Dogs.

PubMed

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

2017-06-01

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

Sleep onset insomnia, daytime sleepiness and sleep duration in relationship to Toxoplasma gondii IgG seropositivity and serointensity

PubMed Central

Ahmad, Zaki; Moustafa, Yara W.; Stiller, John W.; Pavlovich, Mary A.; Raheja, Uttam K.; Gragnoli, Claudia; Snitker, Soren; Nazem, Sarra; Dagdag, Aline; Fang, Beverly; Fuchs, Dietmar; Lowry, Christopher A.; Postolache, Teodor T.

2018-01-01

Toxoplasma gondii (T. gondii) infects central nervous tissue and is kept in relative dormancy by a healthy immune system. Sleep disturbances have been found to precipitate mental illness, suicidal behavior and car accidents, which have been previously linked to T. gondii as well. We speculated that if sleep disruption, particularly insomnia, would mediate, at least partly, the link between T. gondii infection and related behavioral dysregulation, then we would be able to identify significant associations between sleep disruption and T. gondii. The mechanisms for such an association may involve dopamine (DA) production by T. gondii, or collateral effects of immune activation necessary to keep T. gondii in check. Sleep questionnaires from 2031 Old Order Amish were analyzed in relationship to T. gondii-IgG antibodies measured by enzyme-linked immunosorbent assay (ELISA). Toxoplasma gondii seropositivity and serointensity were not associated with any of the sleep latency variables or Epworth Sleepiness Scale (ESS). A secondary analysis identified, after adjustment for age group, a statistical trend toward shorter sleep duration in seropositive men (p = 0.07). In conclusion, it is unlikely that sleep disruption mediates links between T. gondii and mental illness or behavioral dysregulation. Trending gender differences in associations between T. gondii and shorter sleep need further investigation. PMID:29657364

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

USDA-ARS?s Scientific Manuscript database

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...

A multi-event capture-recapture analysis of Toxoplasma gondii seroconversion dynamics in farm cats.

PubMed

Simon, Julie Alice; Pradel, Roger; Aubert, Dominique; Geers, Régine; Villena, Isabelle; Poulle, Marie-Lazarine

2018-06-08

Domestic cats play a key role in the epidemiology of the parasite Toxoplasma gondii by excreting environmentally-resistant oocysts that may infect humans and other warm-blooded animals. The dynamics of Toxoplasma gondii seroconversion, used as a proxy for primo-infection dynamics, was investigated in five cat populations living on farms. Serological tests on blood samples from cats were performed every three months over a period of two years, for a total of 400 serological tests performed on 130 cats. Variations in seroconversion rates and associated factors were investigated using a multi-event capture-recapture modelling approach that explicitly accounted for uncertainties in cat age and serological status. Seroprevalence varied between farms, from 15 to 73%, suggesting differential exposure of cats to T. gondii. In farms with high exposure, cats could become infected before reaching the age of six months. Seroconversion rates varied from 0.42 to 0.96 seroconversions per cat per year and were higher in autumn and winter than in spring and summer. Our results suggest inter-farm and seasonal variations in the risks of exposure to T. gondii oocysts for humans and livestock living on farms. The paper also discusses the role of young cats in the maintenance of environmental contamination by T. gondii oocysts on farms.

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...

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

USDA-ARS?s Scientific Manuscript database

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 ...

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

USDA-ARS?s Scientific Manuscript database

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...

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

USDA-ARS?s Scientific Manuscript database

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...

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

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.

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.

Seroepidemiology of infection with Toxoplasma gondii in migrant agricultural workers living in poverty in Durango, Mexico.

PubMed

Alvarado-Esquivel, Cosme; Campillo-Ruiz, Federico; Liesenfeld, Oliver

2013-04-20

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. 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. 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. 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.

Seroepidemiology of Toxoplasma gondii infection in pregnant women in rural Durango, Mexico.

PubMed

Alvarado-Esquivel, C; Torres-Castorena, A; Liesenfeld, O; García-López, C R; Estrada-Martínez, S; Sifuentes-Alvarez, A; Marsal-Hernández, J F; Esquivel-Cruz, R; Sandoval-Herrera, F; Castañeda, J A; Dubey, J P

2009-04-01

The epidemiology of Toxoplasma gondii infection in pregnant women in rural Mexico is largely unknown. The seroepidemiology of T. gondii infection in 439 pregnant women from 9 communities in rural Durango State, Mexico was investigated. Using commercial enzyme-linked immunoassays, sera were tested for T. gondii IgG, IgM, and avidity antibodies. Prevalences of T. gondii IgG antibodies in the communities varied from 0% to 20%. Overall, 36 (8.2%) of the 439 women had IgG T. gondii antibodies. Ten (2.3%) women had also T. gondii IgM antibodies; IgG avidity was high in all IgM-positive women, suggesting chronic infection. None of the women, however, had delivered a known T. gondii-infected child. The seroprevalence was significantly higher (P < 0.05) in women from low socio-economic conditions (14%) than in those with higher socio-economic status (6.6%). Multivariate analysis showed that T. gondii infection was associated with soil floors at home (adjusted OR = 2.89; 95% CI: 1.12-7.49). This is the first epidemiological study of T. gondii infection in pregnant women in rural Mexico.

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

PubMed

Boucher, Lauren E; Bosch, Jürgen

2014-09-01

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.

[Awareness and infection of Toxoplasma gondii in married childbearing women in Chengde Region].

PubMed

Li, Xue-jing; Xu, Tao; Song, Ren-hao

2014-08-01

To understand Toxoplasma gondii infection and awareness condition of married childbearing women in Chengde Region, so as to provide the evidence for the establishment of control measures. Totally 733 married childbearing women who took physical examination in Chengde Hospital of Traditional Chinese Medicine from July to December in 2013 were investigated by questionnaire to understand the awareness condition on T. gondii infection, then 490 women among them from 3 counties and 2 districts were randomly chosen to detect the Toxoplasma antibodies by ELISA. A total of 733 questionnaires were returned, and 126 women knew related knowledge about T. gondii infection, and the awareness rate was 17.19%( 126/733). Sixty-three women were determined as infected cases, and the infection rate was 12.86%( 63/490). The infection rates of the women who with higher educational level, working as medical staff and living in urban were lower, and the awareness rates of them were higher. The infection rate of T. gondii among the married childbearing women in Chengde Region is high, and the awareness rate of them is low. In order to decrease the infection rate as well as to increase the awareness rate of the population, the health education should be strengthened.

Toxoplasma gondii seroprevalence and association with equine protozoal myeloencephalitis: A case-control study of Californian horses.

PubMed

James, K E; Smith, W A; Packham, A E; Conrad, P A; Pusterla, N

2017-06-01

While toxoplasmosis is not commonly considered a clinical disease of equines, previous seroprevalence studies have reported differing background rates of Toxoplasma gondii infection in horses globally. The objective of this study was to evaluate possible associations between T. gondii seroprevalence and clinical signs of equine protozoal myeloencephalitis (EPM) in horses. Using a case-control study design, 720 Californian horses with neurologic signs compatible with EPM were compared to healthy, non-neurologic horses for the presence of T. gondii antibodies (using indirect fluorescent antibody tests [IFAT]). Toxoplasma gondii seroprevalence among cases and controls was determined at standard serum cut-offs: 40, 80, 160, 320, and 640. At a T. gondii titre cut-off of 320, horses with clinical signs compatible with EPM had 3.55 times the odds of a seropositive test compared to those without clinical signs (P<0.01) when adjusted for covariates. When restricted to the autumn season and at the same titre cut-off, an EPM suspect horse had 6.4 times the odds of testing seropositive to T. gondii, compared to non-neurologic horses. The association between high T. gondii titres and clinical signs compatible with EPM is potentially reflective of toxoplasmosis in equines. Serologic testing of cerebrospinal fluid and isolation of T. gondii in EPM suspect cases should be considered. Future studies investigating the relationship between T. gondii and EPM are warranted. Copyright © 2017 Elsevier Ltd. All rights reserved.

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. Copyright © 2015 Elsevier B.V. All rights reserved.

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...

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

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

USDA-ARS?s Scientific Manuscript database

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...

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

USDA-ARS?s Scientific Manuscript database

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 ...

New Toxoplasma gondii genotypes isolated from free-range chickens from the Fernando de Noronha, Brazil: unexpected findings

USDA-ARS?s Scientific Manuscript database

Worldwide comparison of Toxoplasma gondii isolates from free range chickens has indicated that T. gondii isolates from Brazil are phenotypically and genetically different than isolates from other countries; most strains from Brazil are pathogenic to mice, there is great genetic variability, most iso...

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boucher, Lauren E.; Bosch, Jürgen, E-mail: jbosch@jhu.edu; Johns Hopkins Bloomberg School of Public Health, 615 North Wolfe Street, Baltimore, MD 21205

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 aldolasemore » 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.« less

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

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

PubMed

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.

A brief history and overview of Toxoplasma gondii.

PubMed

Innes, E A

2010-02-01

Toxoplasma gondii was discovered by scientists working in North Africa and Brazil around 100 years ago. The parasite has since been found to be capable of infecting all warm-blooded animals including humans making it one of the most successful parasitic organisms worldwide. The pathogenic potential of T. gondii was recognized in the 1920s and 1930s, in congenitally infected children presenting with the classic triad of symptoms, namely hydrocephalus, retinochoroiditis and encephalitis. In addition, around the same time T. gondii parasites were found to be associated with severe intraocular inflammation. In the 1980s, T. gondii emerged as a major cause of death in patients with acquired immunodeficiency syndrome, illustrating the importance of the immune system in controlling T. gondii infection. T. gondii was reported as a major cause of abortion in sheep in New Zealand in the 1950s, which raised questions about potential new transmission routes for the parasite. The discovery of the cat as the definitive host in the 1960s was a very important finding as it helped to complete our understanding of the parasite's life cycle, and the oocyst stage of T. gondii shed in the faeces of infected cats was found to be an important source of infection for many intermediate hosts and helped to explain infection in herbivorous animals and people with a vegetarian diet. In addition, this stage of the parasite was very robust and could survive in the environment, depending on the climatic conditions, for up to 12-18 months. Knowledge of the parasite's life cycle, transmission routes, risk groups and host immune responses has helped in the development of strategies to control the disease, reduce transmission of the parasite and limit environmental contamination.

High frequency detection of Toxoplasma gondii DNA in human neonatal tissue from Libya.

PubMed

Haq, Sameena Z H; Abushahama, Muftah S; Gerwash, Omar; Hughes, Jacqueline M; Wright, Elizabeth A; Elmahaishi, Mohamed S; Lun, Zhao-Rong; Thomasson, Denise; Hide, Geoff

2016-09-01

Toxoplasma gondii is a parasite that causes significant disease in humans. Toxoplasmosis is normally asymptomatic, unless associated with congenital transmission, or in immunocompromised people. Congenital transmission generally occurs at low frequencies. In this study, we use PCR to investigate possible congenital transmission of T. gondii during pregnancy in a cohort of mothers from Libya. Two hundred and seventy two pregnant women (producing 276 neonates) were recruited to obtain umbilical cord tissue from their neonates at birth; DNA was extracted from that tissue and tested for T. gondii DNA using two specific PCR protocols based on the sag 1 and sag 3 genes. Toxoplasma gondii DNA was detected in the umbilical cord DNA from 27 of the 276 neonates giving a prevalence of 9.9% (95% CI 6.8-13.9%). Compared with more commonly reported rates of congenital transmission of 0.1% of live births, this is high. There was no association of infection with unsuccessful pregnancy. This study shows a high frequency presence of T. gondii DNA associated with neonatal tissue at birth in this cohort of 276 neonates from Libya. Although PCR cannot detect living parasites, there is the possibility that this indicates a higher than usual frequency of congenital transmission. © The Author 2016. Published by Oxford University Press on behalf of Royal Society of Tropical Medicine and Hygiene. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Seroepidemiology of Toxoplasma Gondii Infection in People Applying for Medical Certificates

PubMed Central

Alvarado-Esquivel, Cosme; Sánchez-Anguiano, Luis Francisco; Hernández-Tinoco, Jesús; Pulido-Montoya, Rosa Angélica; Acosta-Rojas, Guadalupe; Estrada-Martínez, Sergio; Pérez-Álamos, Alma Rosa; Vaquera-Enriquez, Raquel; Díaz-Herrera, Arturo; Segura-Moreno, Raúl; Guerrero-Carbajal, María de Lourdes; Liesenfeld, Oliver; García, Isabel Beristain; Rentería-López, María Guadalupe

2016-01-01

Medical certificates are documents that state the health status of a person. This study aimed to determine the seroprevalence and risk factors for Toxoplasma gondii infection in applicants of medical certificates and to investigate seroprevalence association with characteristics of these individuals. We examined 404 applicants in a public health center in Durango City, Mexico for the presence of anti-Toxoplasma IgG and IgM antibodies using enzyme-linked immunoassays. Of the 404 subjects (mean age of 35.94 ± 13.01) studied, 29 (7.2%) were positive for anti-T. gondii IgG antibodies and 9 (31.0%) of them were also positive for anti-T. gondii IgM antibodies. IgG and IgM seropositivities were associated with vision impairment (P = 0.04) and a history of surgery (P = 0.03), respectively. Prevalence of high (>150 IU/ml) IgG antibody levels was associated with hearing impairment (P = 0.03), and histories of lymphadenopathy (P = 0.04) and miscarriages (P = 0.03). Multivariate analysis showed that T. gondii seropositivity was associated with being born out of Durango State (odds ratio [OR] = 4.65; 95% confidence interval [CI]: 1.25–17. 29; P = 0.02) and soil contact (OR = 4.27; 95% CI: 1.71–10.67; P = 0.002) and negatively associated with consumption of sheep meat (OR = 0.12; 95% CI: 0.02–0.65; P = 0.01). These results could be used for the design of optimal preventive measures against toxoplasmosis and its sequelae. PMID:27429791

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.

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...

Seroprevalence of Toxoplasma gondii in Iberian pig sows.

PubMed

Pablos-Tanarro, Alba; Ortega-Mora, Luis Miguel; Palomo, Antonio; Casasola, Francisco; Ferre, Ignacio

2018-05-01

The objective of the present study was to investigate the seroprevalence of Toxoplasma gondii infection in Iberian sows reared in extensive and intensive management conditions and to compare two serologic techniques used for diagnosis. In addition, some possible risk factors associated with the presence of serum antibodies to T. gondii were also studied. Serum samples were collected from 2492 Iberian sows on 14 pig farms. Three types of management systems were included, traditional extensive outdoor farms (five farms), intensive farms with outdoor access (n = 4), and conventional intensive indoor farms (n = 5). The presence of serum antibodies to T. gondii was evaluated by two commercially available tests: an indirect enzyme-linked immunosorbent assay (ELISA) and a direct agglutination test (DAT). Serum antibodies against T. gondii were detected in 237 sows (9.5%) by at least one of the techniques used. The mean seroprevalence of toxoplasmosis in Iberian sows was 5.8% by ELISA and 8.9% by DAT. An agreement kappa-value of 0.68 (95%, CI = 0.63-0.74) was found between both tests. The results from this study suggest that the prevalence of T. gondii antibodies among Iberian sows seems to be moderate-low. The presence of serum antibodies against T. gondii in Iberian sows was associated to an extensive management system and low-level facilities of the farm, sow number (> 1000 animals), presence of cats, absence of rodent control and bird-proof nets in windows, well-water source, feed sources and storage (from the same farm and not stored in silo), absence of fences, and low farm worker qualification.

Contributions of HLA haplotypes, IL8 level and Toxoplasma gondii infection in defining celiac disease's phenotypes.

PubMed

Rostami-Nejad, Mohammad; Hejazi, Seyed Hossein; Peña, Amado Salvador; Asadzadeh-Aghdaei, Hamid; Rostami, Kamran; Volta, Umberto; Zali, Mohammad Reza

2018-05-18

It is not clear why some patients with coeliac disease (CD) present with severe symptoms and small intestinal mucosal damages while others present with milder symptoms and no frank enteropathy. There is no study to assess the associated factors with mild/severe symptoms and enteropathy. The terminologies like latent, silent and potential are difficult to use and are unrepresentative. In the present study we describe coeliac disease's phenotypes based on HLA haplotypes, IL8 production and past infection with Toxoplasma gondii (T. gondii) infection. In this case-control study, sera originating from 150 healthy subjects and 150 patients diagnosed with CD during the years 2013-14 were analyzed for the presence of antibodies specific T. gondii of the IgG and IgM subclasses. The level of IL8 were measured and HLA-DQ2 and HLA-DQ8 alleles were genotyped. The correlation between these parameters and the damages in intestinal mucosal were assessed using an accepted histopathological classification. High levels of IgG antibodies against T. gondii were found in the sera of control group compared to the CD group (52.6% vs. 39.4%, P = 0.02). Mean serum levels of IL8 was significantly higher in CD patients compared with control (P ≤ 0.05). By comparing the level of anti- T. gondii IgG and mucosal damage in celiac disease, we found a significant relationship between the severity of mucosal damages and anti- T. gondii IgG level (P = 0.02). No correlation was detected between Toxoplasma gondii infection and types of HLA (P > 0.05). However, patients with severely abnormal histology carried HLA-DQ2 risk alleles (92 patients (61%)) more often than the controls and those with mild histological abnormalities. CD patients with severe histological changes had more often Toxoplasma gondii infection than those affected with mild histological features. This suggests that CD's phenotypes are correlated to additional factors like infections and to particular HLA DQ2 alleles

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.

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.

Seroprevalence of Toxoplasma gondii infection in feral cats in Qatar.

PubMed

Boughattas, Sonia; Behnke, Jerzy; Sharma, Aarti; Abu-Madi, Marawan

2017-01-18

Cats are essential in the life cycle of Toxoplasma gondii as they can shed the environmentally resistant oocysts after acquiring infection. Human populations living in cities with high densities of feral cats are therefore likely to be at risk of infection. The current study is the first to estimate the seroprevalence of T. gondii in the feral cat population in Qatar. We investigated the seroprevalence of T. gondii among 495 adult cats from urban and suburban districts in Qatar. Using results from the Modified Agglutination Test, we fitted statistical models with host sex, area and season as explanatory factors and seropositivity as the outcome. The analysis revealed an overall seroprevalence of 82%. Seroprevalence was significantly higher in the summer season (P = 0.006). No significant difference was detected (P > 0.05) between seroprevalence in female and male cats and in cats from urban and suburban districts of Qatar. Despite the seasonal difference, the observed seroprevalence of T. gondii suggests high environmental contamination throughout the year, with some female cats generating more intense responses compared to males. Both findings merit further investigations.

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

PubMed

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

2015-02-05

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

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

PubMed

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

2012-04-01

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

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. Published by Elsevier B.V.

Molecular Evidence of Toxoplasma gondii, Neospora caninum, and Encephalitozoon cuniculi in Red Foxes ( Vulpes vulpes).

PubMed

Lukášová, Radka; Marková, Jiřina; Bártová, Eva; Murat, Jean-Benjamin; Sedlák, Kamil

2018-05-07

Toxoplasma gondii, Neospora caninum, and Encephalitozoon cuniculi are important infectious agents, with T. gondii and E. cuniculi having zoonotic potential. There are two main clonal lineages (types I and II) of T. gondii in Europe, but little is known about genotypes of T. gondii in wild animals. The aim of our study was molecular detection of these three pathogens in tissues of wild red foxes ( Vulpes vulpes) from the Czech Republic. Using PCR (B1 gene), we detected T. gondii in 10% of the animals that we tested ( n=100); N. caninum and E. cuniculi were not detected. The T. gondii samples were genotyped by single multiplex PCR assay with 15 microsatellite markers. Five samples were successfully genotyped as genotype II, a unique finding for T. gondii isolated from red foxes from the Czech Republic.

Surface binding properties of aged and fresh (recently excreted) Toxoplasma gondii oocysts

USDA-ARS?s Scientific Manuscript database

The surface properties of aged (stored for 10 years) and fresh (recently excreted) oocysts of Toxoplasma gondii were investigated using monoclonal antibody (mAb) and lectin-binding assays. Fresh oocysts bound a wall-specific mAb labeled with fluorescein isothiocyanate while aged oocysts did not. In ...

Toxoplasmosis in the Caribbean islands: literature review, seroprevalence in pregnant women in ten countries, isolation of viable Toxoplasma gondii from dogs from St. Kitts, West Indies with report of new T. gondii genetic types.

PubMed

Dubey, Jitender P; Verma, Shiv Kumar; Villena, Isabelle; Aubert, Dominique; Geers, Régine; Su, Chunlei; Lee, Elise; Forde, Martin S; Krecek, Rosina C

2016-04-01

Little is currently known of clinical toxoplasmosis in humans and animals in the Caribbean. We investigated the prevalence of IgG and IgM antibodies in 437 pregnant women from 10 English speaking Caribbean countries. Overall, antibodies (IgG) to Toxoplasma gondii (modified agglutination test, MAT, cut-off 1:6) were found in 174 (39.8 %) of 437 human sera; specifically 12 of 38 from Antigua-Barbuda, 26 of 52 from Belize, 9 of 50 from Bermuda, 29 of 49 from Dominica, 18 of 49 from Grenada, 16 of 47 from Jamaica, 5 of 15 from Montserrat, 8 of 44 from St. Kitts/Nevis, 24 of 45 from St. Lucia, and 27 of 50 from St. Vincent/Grenadines were seropositive. All IgG-positive sera were tested for IgM antibodies using the immunocapture method; all sera were negative for IgM antibodies. Additionally, tissues and sera of 45 dogs from St. Kitts were examined for T. gondii infection. Antibodies (IgG, MAT, 1:≥25) were found in 19 (42.2 %) of 45 dogs. Muscle samples (tongue, leg) of 19 seropositive dogs were digested in pepsin, and homogenates were bioassayed in mice. Viable T. gondii were isolated from 6 dogs. T. gondii isolates were further propagated in cell culture. PCR-RFLP genotyping of cell culture derived tachyzoites using 10 genetic markers, SAG1, SAG2 (5' and 3' SAG2, and alt.SAG2) SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico revealed that 4 isolates were ToxoDB PCR-RFLP genotype #2, and 2 were new genotypes #264 and #265. Review of 22 viable T. gondii isolates from chickens, dogs, and cats from Grenada and St. Kitts revealed that 1 isolate was type II, 13 were type III, and 8 were atypical. Thus, type III strains were predominant. Overall, the study revealed high prevalence of T. gondii in the Caribbean islands.

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

USDA-ARS?s Scientific Manuscript database

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...

Prevalence of Toxoplasma gondii infection in household and feral cats in Korea.

PubMed

Kim, Sung-Eon; Choi, Ran; Kang, Seung-Won; Hyun, Changbaig

2017-09-01

This study was designed to investigate the prevalence rate of Toxoplasma gondii ( T. gondii ) infection in household cats in Korea. One hundred household cats and 50 feral cats from nine of the largest cities in Korea were enrolled in this study. The tests performed in this survey was an in-house rapid screen IgG and IgM combo test, faecal PCR test for T. gondii oocysts, and an ELISA immunoassay for IgG antibodies. There were no household cats positive for T. gondii infection detected using the in-house IgG and IgM rapid screen combo test, although 6/50 and 0/50 feral cats were positive in IgG and IgM tests, respectively. This initial finding was confirmed by subsequent ELISA test for IgG antibody and PCR for T. gondii in faeces. Despite the higher prevalence rate of the disease in feral cats in Korea, we did not find any household cats that were either infected or exposed previously to T. gondii in our study population. Our study indicates that there is minimal risk of T. gondii transmission from household cats to human in Korea.

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

PubMed

Prestrud, Kristin Wear; Dubey, J P; Asbakk, Kjetil; Fuglei, Eva; Su, C

2008-02-14

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 isolate and genetically characterize the parasite from arctic foxes in Svalbard. Eleven foxes were trapped live in Grumant (78 degrees 11'N, 15 degrees 09'E), Svalbard, in September 2005 and 2006. One of the foxes was found to be seropositive to T. gondii by the modified agglutination test (MAT). The fox was euthanized and its heart and brain were bioassayed in mice for the isolation of T. gondii. All 10 mice inoculated with brain tissue and one of the five inoculated with heart developed MAT antibodies, and tissue cysts were found in the brains of seropositive mice. Two cats fed tissues from infected mice shed T. gondii oocysts. Genotyping using 10 PCR-RFLP markers and DNA sequencing of gene loci BSR4, GRA6, UPRT1 and UPRT2 determined the isolate to be Type II strain, the predominant T. gondii lineage in the world.

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

Movement of Toxoplasma gondii Oocysts in Unsaturated Natural Soils

NASA Astrophysics Data System (ADS)

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

2017-04-01

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

Adenosine metabolism in Toxoplasma gondii: potential targets for chemotherapy.

PubMed

el Kouni, Mahmoud H

2007-01-01

Toxoplasma gondii is an intracellular parasitic protozoan that infects approximately a billion people worldwide. Infection with T. gondii represents a major health problem for immunocompromised individuals, such as AIDS patients, organ transplant recipients, and the unborn children of infected mothers. Currently available drugs usually do not eradicate infection and as many as 50% of the patients do not respond to this therapy. Furthermore, they are ineffective against T. gondii tissue cysts. In addition, prolonged exposure to these drugs induces serious host toxicity forcing the discontinuation of the therapy. Finally, there is no effective vaccine currently available for the treatment of toxoplasmosis. Therefore, it is necessary to develop new and effective drugs for the treatment and management of toxoplasmosis. The rational design of a drug depends on the exploitation of fundamental biochemical or physiological differences between pathogens and their host. Some of the most striking differences between T. gondii and their mammalian host are found in purine metabolism. T. gondii, like most parasites studied, lack the ability to synthesize purines do novo and depend on the salvage of purines from their host to satisfy their requirements of purines. In this respect, the salvage of adenosine is the major source of purines in T. gondii. Therefore, interference with adenosine uptake and metabolism in T. gondii can be selectively detrimental to the parasite. The host cells, on the other hand, can still obtain their purine requirements by their de novo pathways. This review will focus on the broad aspects of the adenosine transport and the enzyme adenosine kinase (EC 2.7.1.20) which are the two primary routes for adenosine utilization in T. gondii, in an attempt to illustrate their potentials as targets for chemotherapy against this parasite.

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

PubMed

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

2016-02-01

Serological assays for the diagnosis of toxoplasmosis mostly rely on the tachyzoite specific antigens of Toxoplasma gondii, which are difficult to produce by conventional methods. The aim of this study was to clone and express of GRA7 protein of T. gondii and evaluate its potential for immunodiagnosis of toxoplasmosis in cancer patients. As well as validate the results using a new molecular assay, LAMP technique. The GRA7 gene was successfully cloned, expressed and purified by affinity chromatography and the production was evaluated by SDS PAGE, dot blot and western blot analyses. The rGRA7 was used for developing an ELISA based on the rGRA7 using sera from patients with toxoplasmosis and healthy controls. Furthermore, 50 serum samples from leukemic children infected with toxoplasmosis and 50 seronegative controls were included to evaluate the sensitivity and specificity of rGRA7 based ELISA. Finally, the LAMP technique was used to assess the accuracy and validity of the results obtained by rGRA7 based ELISA. The consistency of the results of two tests was determined by using the Kappa coefficient of agreement. The rGRA7 showed higher and optimum immunoreactivity with 1:100 dilution of serum from Toxoplasma infected patients. The sensitivity and specificity of test were calculated as 92 and 94%, respectively. According to the Kappa coefficient of agreement, there was a significant conformance between the results obtained by ELISA based on the rGRA7 and the results of LAMP technique (≈96%, P<0.001). Findings of the present study showed that rGRA7 can be used as a potential immunogenic antigen for developing immunodiagnostic tools for immunodiagnosis of toxoplasmosis in patients including patients with cancer. Copyright © 2015. Published by Elsevier GmbH.

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

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

USDA-ARS?s Scientific Manuscript database

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...

Molecular diagnosis of toxoplasmosis: value of the buffy coat for the detection of circulating Toxoplasma gondii.

PubMed

Brenier-Pinchart, Marie-Pierre; Capderou, Elodie; Bertini, Rose-Laurence; Bailly, Sébastien; Fricker-Hidalgo, Hélène; Varlet-Marie, Emmanuelle; Murat, Jean-Benjamin; Sterkers, Yvon; Touafek, Fériel; Bastien, Patrick; Pelloux, Hervé

2015-08-01

Early detection of Toxoplasma tachyzoites circulating in blood using PCR is recommended for immunosuppressed patients at high risk for disseminated toxoplasmosis. Using a toxoplasmosis mouse model, we show that the sensitivity of detection is higher using buffy coat isolated from a large blood volume than using whole blood for this molecular monitoring. Copyright © 2015 Elsevier Inc. All rights reserved.

Can the common brain parasite, Toxoplasma gondii, influence human culture?

PubMed Central

Lafferty, Kevin D

2006-01-01

The latent prevalence of a long-lived and common brain parasite, Toxoplasma gondii, explains a statistically significant portion of the variance in aggregate neuroticism among populations, as well as in the ‘neurotic’ cultural dimensions of sex roles and uncertainty avoidance. Spurious or non-causal correlations between aggregate personality and aspects of climate and culture that influence T. gondii transmission could also drive these patterns. A link between culture and T. gondii hypothetically results from a behavioural manipulation that the parasite uses to increase its transmission to the next host in the life cycle: a cat. While latent toxoplasmosis is usually benign, the parasite's subtle effect on individual personality appears to alter the aggregate personality at the population level. Drivers of the geographical variation in the prevalence of this parasite include the effects of climate on the persistence of infectious stages in soil, the cultural practices of food preparation and cats as pets. Some variation in culture, therefore, may ultimately be related to how climate affects the distribution of T. gondii, though the results only explain a fraction of the variation in two of the four cultural dimensions, suggesting that if T. gondii does influence human culture, it is only one among many factors. PMID:17015323

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

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

PubMed

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

2012-06-01

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

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

USDA-ARS?s Scientific Manuscript database

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...

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

USDA-ARS?s Scientific Manuscript database

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...

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

PubMed Central

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

2012-01-01

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

First report of genotype #65 of Toxoplasma gondii in pigs.

PubMed

Samico-Fernandes, Erika Fernanda Torres; de Melo, Renata Pimentel Bandeira; de Cássia Peixoto Kim, Pomy; de Almeida, Jonatas Campos; de Barros, Luiz Daniel; Garcia, João Luis; da Silva, Jean Carlos Ramos; Mota, Rinaldo Aparecido

2015-10-01

The aim of the present study was to isolate and genotype Toxoplasma gondii from pigs slaughtered for human consumption in northeastern Brazil. Indirect immunofluorescence antibody test (IFAT) was used to screen positive pigs. Tissues samples of animals with antibody titers ≥64 were submitted to bioassay in mice. One isolate of T. gondii was obtained, and the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique, using 11 markers (SAG1, SAG2, altSAG2, SAG3, BTUB, GRA6, c228, c292, L358, PK1, and APICO), was applied to evaluate the genetic variability. DNA from reference strains was used as a positive control. By means of genetic analysis, genotype ToxoDB #65 was identified, which is considered an atypical strain. This is the first record of genotype #65 in pigs. Thus, further studies in this region are necessary to determine the genetic variability of T. gondii in pigs and possible impact on public health.

Isolation of purified oocyst walls and sporocysts from Toxoplasma gondii.

PubMed

Everson, William V; Ware, Michael W; Dubey, J P; Lindquist, H D Alan

2002-01-01

Toxoplasma gondii oocysts are environmentally resistant and can infect virtually all warm-blooded hosts, including humans and livestock. Little is known about the biochemical basis for this resistance of oocysts, and mechanism for excystation of T. gondii sporozoites. The objective of the present study was to evaluate different methods (mechanical fragmentation, gradients, flow cytometry) to separate and purify T. gondii oocyst walls and sporocysts. Oocyst walls were successfully separated and purified using iodixanol gradients. Sporocysts were successfully separated and purified using iodixanol and Percoll gradients. Purification was also achieved by flow cytometry. Flow cytometry with fluorescence-activated cell sorting (FACS) yielded analytical quantities of oocyst walls and intact sporocysts. Flow cytometry with FACS also proved useful for quantitation of purity obtained following iodixanol gradient fractionation. Methods reported in this paper will be useful for analytical purposes, such as proteomic analysis of components unique to this life cycle stage, development of detection methods, or excystation studies.

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

USDA-ARS?s Scientific Manuscript database

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...

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

USDA-ARS?s Scientific Manuscript database

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...

Seroprevalence, isolation, and co-infection of multiple Toxoplasma gondii strains in individual bobcats (Lynx rufus) from Mississippi, USA

USDA-ARS?s Scientific Manuscript database

Toxoplasma gondii causes lifelong chronic infection in both feline definitive hosts and intermediate hosts. Multiple exposures of the parasite are likely to occur in nature because of high environmental contamination. Here, we present data of high seroprevalence and multiple T. gondii strain co-infe...

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

USDA-ARS?s Scientific Manuscript database

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...

Toxoplasma gondii-A Gastrointestinal Pathogen Associated with Human Brain Diseases.

PubMed

Severance, E G; Xiao, J; Jones-Brando, L; Sabunciyan, S; Li, Y; Pletnikov, M; Prandovszky, E; Yolken, R

2016-01-01

Serious psychiatric disorders such as schizophrenia, bipolar disorder, and major depression are important causes of mortality and morbidity worldwide. While these are primarily diseases involving altered brain functioning, numerous studies have documented increased rates of gastrointestinal inflammation and dysfunction in many individuals with these disorders. Toxoplasma gondii is an apicomplexan protozoan intracellular parasite with a widespread distribution in both developed and developing countries. Toxoplasma organisms enter the ecosystem through the shedding of oocysts by Toxoplasma-infected felines. In almost all cases of postnatal human infection, Toxoplasma enters its hosts through the intestinal tract either by the ingestion of oocysts or by the consumption of meat from food animals which themselves were infected by Toxoplasma oocysts. It had previously been thought that most cases of Toxoplasma infection in immune competent children and adults were inapparent and asymptomatic. However, recent studies cast doubt on this concept as exposure to Toxoplasma has been associated with a range of acute and chronic symptoms. Of particular note has been the finding of an increased rate of a range of neurological and psychiatric disorders associated with serological evidence of Toxoplasma exposure. A role of Toxoplasma infection in brain diseases is also supported by the consistent finding of altered cognition and behavior in animal models of infections. Much of the attention relating to the role of Toxoplasma infection in neuropsychiatric disorders has focused on the brain, where Toxoplasma tissue cysts can persist for extended periods of time. However, recent discoveries relating to the role of the gastrointestinal tract in cognition and behavior suggest that Toxoplasma may also increase susceptibility to human brain diseases through immune activation, particularly involving the gastrointestinal mucosa. The study of the pathways relating to the pathobiology and

Seroepidemiology of infection with Toxoplasma gondii in patients with vision and hearing impairments, cancer, HIV, or undergoing hemodialysis in Durango, Mexico

USDA-ARS?s Scientific Manuscript database

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...

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

PubMed

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

2017-07-11

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

Isolation of Toxoplasma gondii from animals in Durango, Mexico.

PubMed

Dubey, J P; Velmurugan, G V; Alvarado-Esquivel, C; Alvarado-Esquivel, D; Rodríguez-Peña, S; Martínez-García, S; González-Herrera, A; Ferreira, L R; Kwok, O C H; Su, C

2009-04-01

Little is known concerning the epidemiology of Toxoplasma gondii infection in people and animals in rural Mexico. Serum samples and tissues from 150 dogs (Canis familaris), 150 cats (Felis catus), 65 opossums (Didelphis virginianus), 249 rats (Rattus spp.), 127 mice (Mus musculus), and 69 squirrels (Spermophilus variegatus) from the Durango area were evaluated for T. gondii infection. Using a modified agglutination test and a serum dilution of 1:25, antibodies to this parasite were found in 68 (45.3%) of 150 dogs, 14 (9.3%) of 150 cats, 11 (16.6%) of 66 opossums, 2 (0.8%) of 249 rats, 4 (3.1%) of 127 mice, and 0 of 69 squirrels. Tissues (brain and heart) of dogs, cats, opossums, rats, mice, and squirrels were bioassayed in mice for the presence of T. gondii. Viable T. gondii was isolated in tissues from 3 of 28 seropositive dogs and 5 of 8 seropositive cats, but not from the other animals. The DNA obtained from the 3 T. gondii isolates from dogs, 6 isolates from 5 cats, and 4 isolates from free-range chickens from Mexico, previously isolated, were genotyped. The PCR-RFLP typing, which used 11 markers (B 1, SAGI, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico), identified 5 genotypes. One genotype (the 4 chicken isolates) belongs to the clonal Type III lineage, three genotypes were reported in previous reports, and 1 genotype is unique.

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. Copyright © 2015 Elsevier B.V. All rights reserved.

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

USDA-ARS?s Scientific Manuscript database

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...

Seroprevalence of Toxoplasma gondii in captive antillean manatee (Trichechus manatus manatus) in Brazil

USDA-ARS?s Scientific Manuscript database

Antillean manatees (Trichechus manatus manatus) are aquatic mammals that inhabit marine waters from Central America to the northeastern region of Brazil and they are an endangered species. Infection with Toxoplasma gondii through intake of water or food contaminated with oocysts has been reported am...

Antibodies to Toxoplasma gondii and Leishmania spp. in domestic cats from Luanda, Angola

USDA-ARS?s Scientific Manuscript database

Toxoplasma gondii and Leishmania spp. are zoonotic agents of importance to public health, with domestic cats as potential reservoirs for both protozoal infections. The present study aimed at assessing for the first time the seroprevalence of these zoonotic parasites in a domestic feline population l...

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. © N. Zhang et al., published by EDP Sciences, 2016.

Prevalence of Toxoplasma gondii and HIV infection among pregnant women in Ibadan North Local Government, Oyo State.

PubMed

Awobode, H O; Olubi, I C

2014-12-01

Toxoplasmosis, a disease caused by Toxoplasma gondii poses a risk of congenital infection during pregnancy in infected women. The disease poses a threat of ocular and neurological sequelae in congenitally ilfected infants and HIV patients; however, there is little valuable information on its prevalence in Ibadan. A cross sectional study of pregnant women attending antenatal care in three primary healthcare centres in Ibadan was carried out. 179 women were screened for T gondii infection using PCR, 83 of these were also screened for HIV. Forty nine (27.4%) were positive for T gondii, and 2(2.4%) were HIV positive (P = 0.002, OR = 0.28, CL = 95%). 27 (15.1%) of the infected women were in third trimester, with 20 (11.2%) and 2 (1.1%) in second and first trimester respectively. 18 (10.1%) positive cases were identified among the primigravidas and 31 (17.2%) among the multigravidas. Risk factors associated with Toxoplasma infection were assessed, and the source of drinking water and the types of animals around habitation were found to be significantly associated with the presence of Toxoplasma infection (P = 0.002, OR = 2.109 and P = 0.004, OR = 1.693 respectively). The high prevalence among women in third trimester may indicate high risk of congenital infection, and the significant association found between the source of drinking water and infection suggests environmental contamination as a major possible mode of infection. The need to educate pregnant women about the transmission mechanisms of T. gondii, and the effects of the infection on neonates and babies is pertinent in order to effectively control Toxoplasma infection.

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

PubMed

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

2011-12-29

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 (n=492). Overall, antibodies to T. gondii were found in 174 (31%) of 562 goats, with titers of 1:25 in 18, 1:50 in 12, 1:100 in 10, 1:200 in 30, 1:400 in 32, 1:800 in 40, 1:1600 in 17, and 1:3200 or higher in 15. Seroprevalence of T. gondii increased with age, and varied with breed and geographic region; goats raised in the semi-desert region (Nubian breed) had a significantly higher seroprevalence (32.7%) than those raised in the mountains (mixed breed) (18.6%). Seropositive goats were found in all 12 (100%) farms sampled. This is the first report of T. gondii infection in goats in Durango State, Mexico. Results indicate that infected goats are likely an important source of T. gondii infection in humans in Durango State. Copyright © 2011 Elsevier B.V. All rights reserved.

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

PubMed

Alvarado-Esquivel, C; Rodríguez-Peña, S; Villena, I; Dubey, J P

2012-10-01

The seroprevalence of Toxoplasma gondii infection in horses in Mexico is unknown. Therefore, antibodies to T. gondii were assessed 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. Antibodies to T. gondii were found in 30 (6.1%) of 495 horses, with MAT titers of 1:25 in 19, 1:50 in 6, and 1:100 in 5. Seropositive horses were found in 8 (44.4%) of 18 farms sampled in all 3 municipalities. Age, gender, and breed of horses did not influence significantly the seroprevalence of T. gondii infection. The seroprevalence in horses was higher in rural (7.8%) versus urban (0%) areas, and in larger herds (30-64 horses, 7.8%) versus smaller ones (3-28, 3.5%). The seroprevalence was higher in stall fed (16.5%) than in pastured horses (3.1%). Results indicate that infected horses represent a potential source of T. gondii infection for humans in Mexico. This is the first report of T. gondii infection in horses in Mexico.

Toxoplasma gondii tissue cyst purification using Percoll gradients

PubMed Central

Watts, Elizabeth A.; Dhara, Animesh; Sinai, Anthony P.

2017-01-01

The protozoan parasite Toxoplasma gondii is capable of infecting all warm blooded animals and humans. Infectious, transmissible forms of the parasite include oocysts produced by the sexual cycle within the definitive feline host and tissue cysts that form Toxoplasma in the CNS and muscle during the asexual cycle within all chronically infected warm-blooded hosts. These tissue cysts are populated with slow growing bradyzoites which have been until recently thought to be dormant entities in the context of immune sufficiency. Reactivation to active growth during immune suppression is of critical clinical importance. Yet we know little about tissue cysts or the bradyzoites they house as the diversity of tissue cysts cannot be replicated in cell culture systems. Our optimization of tissue cyst purification from the brains of infected mice using Percoll gradients provides an efficient means to recover in vivo derived tissue cysts that can be applied to imaging, cell-biologic, biochemical, transcriptomic and proteomic analyses. PMID:28510363

Urine sample used for detection of toxoplasma gondii infection by loop-mediated isothermal amplification (LAMP).

PubMed

Hu, Xin; Pan, Chang-Wang; Li, Ya-Fei; Wang, Han; Tan, Feng

2012-02-01

In this study, a loop-mediated isothermal amplification (LAMP) assay was established to detect Toxoplasma gondii DNA in mice infected with T. gondii PRU strain. This LAMP assay was based on the sequence of highly repetitive B1 gene. The detection limit of T. gondii LAMP assay was 1 pg of T. gondii DNA, which was evaluated using 10-fold serially diluted DNA of cultured parasites. The LAMP assay was also highly specific for T. gondii and able to detect T. gondii DNA in urine of mice treated with dexamethasone at 90 day post infection (p.i.), although this assay could not detect the DNA in mice urine 2-6 days p.i. These results demonstrated that LAMP is effective for evaluation of therapy effectiveness for T. gondii infection. The established LAMP assay may represent a useful and practical tool for the routine diagnosis and therapeutic evaluation of human toxoplasmosis.

Detection of Toxoplasma gondii oocysts in different water resources by Loop Mediated Isothermal Amplification (LAMP).

PubMed

Gallas-Lindemann, Carmen; Sotiriadou, Isaia; Mahmoodi, Mohammad Reza; Karanis, Panagiotis

2013-02-01

Human toxoplasmosis is potentially contracted due to consumption of contaminated drinking water and represents an increasing public health risk worldwide. Toxoplasma gondii oocysts can be resistant to standard disinfection processes, including UV radiation. Increased awareness of the risk of waterborne toxoplasmosis outbreaks has led to an increase in research interest in the detection of oocysts in environmental water systems. Ninety-five environmental water samples from the Lower Rhine area in Germany have been included in the study and examined for the presence of Toxoplasma. Water samples were filtered or flocculated by aluminum sulfate and purified by sucrose density gradient. DNA was then extracted, and the DNA samples were then examined by LAMP analysis. T. gondii DNA was detected in eight out of 83 (9.6%) influent and effluent samples obtained from wastewater treatment plants. All samples (n=12) from the surface, ground, raw and tap waters tested negative. The purpose of this work was to investigate the occurrence and distribution of Toxoplasma oocysts on the Lower Rhine in Germany. Our study provides evidence that the assay is a sensitive, specific, rapid and cost effective method for the detection of T. gondii and is useful for both the investigations of cases of waterborne outbreaks and for identifying the source of contamination. Copyright © 2012 Elsevier B.V. All rights reserved.

Antibody detection and molecular characterization of Toxoplasma gondii from bobcats (Lynx rufus),domestic cats (Felis catus),and wildlife from Minnesota, USA

USDA-ARS?s Scientific Manuscript database

Toxoplasma gondii and Sarcocystis felis are protozoan parasites that infect both, domestic and wild felids. Bobcats are the definitive host in the life cycle of T. gondii. Limited information’s are available concerning T. gondii infection in different populations of bobcats. In the paper, the preval...

Anti-gluten immune response following Toxoplasma gondii infection in mice.

PubMed

Severance, Emily G; Kannan, Geetha; Gressitt, Kristin L; Xiao, Jianchun; Alaedini, Armin; Pletnikov, Mikhail V; Yolken, Robert H

2012-01-01

Gluten sensitivity may affect disease pathogenesis in a subset of individuals who have schizophrenia, bipolar disorder or autism. Exposure to Toxoplasma gondii is a known risk factor for the development of schizophrenia, presumably through a direct pathological effect of the parasite on brain and behavior. A co-association of antibodies to wheat gluten and to T. gondii in individuals with schizophrenia was recently uncovered, suggesting a coordinated gastrointestinal means by which T. gondii and dietary gluten might generate an immune response. Here, we evaluated the connection between these infectious- and food-based antigens in mouse models. BALB/c mice receiving a standard wheat-based rodent chow were infected with T. gondii via intraperitoneal, peroral and prenatal exposure methods. Significant increases in the levels of anti-gluten IgG were documented in all infected mice and in offspring from chronically infected dams compared to uninfected controls (repetitive measures ANOVAs, two-tailed t-tests, all p≤0.00001). Activation of the complement system accompanied this immune response (p≤0.002-0.00001). Perorally-infected females showed higher levels of anti-gluten IgG than males (p≤0.009) indicating that T. gondii-generated gastrointestinal infection led to a significant anti-gluten immune response in a sex-dependent manner. These findings support a gastrointestinal basis by which two risk factors for schizophrenia, T. gondii infection and sensitivity to dietary gluten, might be connected to produce the immune activation that is becoming an increasingly recognized pathology of psychiatric disorders.

Seroprevalence of Toxoplasma gondii in humans and pigs in North Sulawesi, Indonesia.

PubMed

Tuda, Josef; Adiani, Sri; Ichikawa-Seki, Madoka; Umeda, Kousuke; Nishikawa, Yoshifumi

2017-10-01

Toxoplasma gondii, an intracellular protozoan parasite, is a major public health concern throughout the world. Importantly, toxoplasmosis has several adverse effects, including neurological and ocular diseases. There are currently no data on the prevalence of T. gondii infection in humans or animals in North Sulawesi, although Indonesia is known to have a high seroprevalence of this parasite. In this study, the prevalence of T. gondii was determined in samples of humans and pigs from North Sulawesi using the latex agglutination test. In total, 856 human were sampled and 58.5% of whom were positive for T. gondii. Although the antibody prevalence in male and female children aged 0-9years was <10%, the prevalence in individuals over 10years old was >40% in both sexes, suggesting that the transmission rate of the parasite to humans is extremely high in this area. However, the overall prevalence of T. gondii in pigs was only 2.3%. Our study indicates a high incidence of T. gondii infection in humans. Therefore, a survey of the prevalence of T. gondii among different infection sources is required to determine the major risk factors for infection in North Sulawesi. Copyright © 2017 Elsevier B.V. All rights reserved.

Evaluation of Anti-Toxoplasma gondii Effect of Ursolic Acid as a Novel Toxoplasmosis Inhibitor.

PubMed

Choi, Won Hyung; Lee, In Ah

2018-05-09

This study was carried out to evaluate the anti-parasitic effect of ursolic acid against Toxoplasma gondii ( T. gondii ) that induces toxoplasmosis, particularly in humans. The anti-parasitic effects of ursolic acid against T. gondii -infected cells and T. gondii were evaluated through different specific assays, including immunofluorescence staining and animal testing. Ursolic acid effectively inhibited the proliferation of T. gondii when compared with sulfadiazine, and consistently induced anti- T. gondii activity/effect. In particular, the formation of parasitophorous vacuole membrane (PVM) in host cells was markedly decreased after treating ursolic acid, which was effectively suppressed. Moreover, the survival rate of T. gondii was strongly inhibited in T. gondii group treated with ursolic acid, and then 50% inhibitory concentration (IC 50 ) against T. gondii was measured as 94.62 μg/mL. The T. gondii -infected mice treated with ursolic acid indicated the same survival rates and activity as the normal group. These results demonstrate that ursolic acid causes anti- T. gondii action and effect by strongly blocking the proliferation of T. gondii through the direct and the selective T. gondii -inhibitory ability as well as increases the survival of T. gondii -infected mice. This study shows that ursolic acid has the potential to be used as a promising anti- T. gondii candidate substance for developing effective anti-parasitic drugs.

Localization of azithromycin in Toxoplasma gondii-infected cells.

PubMed Central

Schwab, J C; Cao, Y; Slowik, M R; Joiner, K A

1994-01-01

Agents effective against intracellular pathogens must enter infected cells, crossing vacuolar membranes surrounding the organisms and then penetrating into the microbe and localizing to the microbial target site. We have characterized these parameters for azithromycin entry into Toxoplasma gondii-infected Chinese hamster ovary cells and murine macrophage-like J774 cells. Azithromycin uptake into infected host cells was concentrative and was dependent upon proton gradients. Subcellular fractionation of azithromycin-loaded infected CHO cells demonstrated > 95% intracellular drug in host cell lysosomes and cytosol, with < 5% associated with the parasite. Uptake of azithromycin into the T. gondii vacuole increased if parasites were coated with antibody prior to internalization by murine J774 cells, conditions which result in the formation of acidified phagolysosomes. No redistribution or retention of azithromycin in the parasite was observed when drug efflux from antibiotic-loaded infected CHO cells was monitored. Azithromycin entry into extracellular T. gondii was concentrative, was temperature and pH dependent, and was not different when azithromycin-sensitive and -resistant parasites were compared. These results demonstrate that azithromycin concentrates primarily in acidified compartments in parasites and host cells. The high concentration of azithromycin within these compartments may not be biologically relevant to inhibition of intracellular parasite growth by this agent. PMID:7979295

Dynamic two-photon imaging of the immune response to Toxoplasma gondii infection.

PubMed

Luu, L; Coombes, J L

2015-03-01

Toxoplasma gondii is a highly successful parasite that can manipulate host immune responses to optimize its persistence and spread. As a result, a highly complex relationship exists between T. gondii and the immune system of the host. Advances in imaging techniques, and in particular, the application of two-photon microscopy to mouse infection models, have made it possible to directly visualize interactions between parasites and the host immune system as they occur in living tissues. Here, we will discuss how dynamic imaging techniques have provided unexpected new insight into (i) how immune responses are dynamically regulated by cells and structures in the local tissue environment, (ii) how protective responses to T. gondii are generated and (iii) how the parasite exploits the immune system for its own benefit. © 2014 John Wiley & Sons Ltd.

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

USDA-ARS?s Scientific Manuscript database

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...

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

USDA-ARS?s Scientific Manuscript database

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...

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

USDA-ARS?s Scientific Manuscript database

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 ...

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

USDA-ARS?s Scientific Manuscript database

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...

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

USDA-ARS?s Scientific Manuscript database

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...

Genetic Polymorphisms and Phenotypic Profiles of Sulfadiazine-Resistant and Sensitive Toxoplasma gondii Isolates Obtained from Newborns with Congenital Toxoplasmosis in Minas Gerais, Brazil.

PubMed

Silva, Letícia Azevedo; Reis-Cunha, João Luís; Bartholomeu, Daniella Castanheira; Vítor, Ricardo Wagner Almeida

2017-01-01

Previous Toxoplasma gondii studies revealed that mutations in the dhps (dihydropteroate synthase) gene are associated with resistance to sulfonamides. Although Brazilian strains are genotypically different, very limited data are available regarding the susceptibility of strains obtained from human to sulfonamides. The aim of this study was to evaluate the efficacy of sulfadiazine (SDZ) against Brazilian isolates of T. gondii and verify whether isolates present polymorphisms in the dhps gene. We also investigated whether the virulence-phenotype and/or genotype were associated with the profile of susceptibility to SDZ. Five T. gondii isolates obtained from newborns with congenital toxoplasmosis were used to verify susceptibility. Mice were infected with 104 tachyzoites and orally treated with different doses of SDZ. The mortality curve was evaluated by the Log-rank test. The presence of polymorphisms in the dhps gene was verified using sequencing. A descriptive analysis for 11 Brazilian isolates was used to assess the association between susceptibility, genotype, and virulence-phenotype. Statistical analysis showed that TgCTBr03, 07, 08, and 16 isolates were susceptible to SDZ, whereas TgCTBr11 isolate presented a profile of resistance to SDZ. Nineteen polymorphisms were identified in dhps exons. Seven polymorphisms corresponded to non-synonymous mutations, with four being new mutations, described for the first time in this study. No association was found between the profile of susceptibility and the virulence-phenotype or genotype of the parasite. There is a high variability in the susceptibilities of Brazilian T. gondii strains to SDZ, with evidence of drug resistance. Despite the large number of polymorphisms identified, the profile of susceptibility to SDZ was not associated with any of the dhps variants identified in this study. Other genetic factors, not yet determined, may be associated with the resistance to SDZ; thus, further studies are needed as a basis

Genetic Polymorphisms and Phenotypic Profiles of Sulfadiazine-Resistant and Sensitive Toxoplasma gondii Isolates Obtained from Newborns with Congenital Toxoplasmosis in Minas Gerais, Brazil

PubMed Central

Silva, Letícia Azevedo; Reis-Cunha, João Luís; Bartholomeu, Daniella Castanheira; Vítor, Ricardo Wagner Almeida

2017-01-01

Background Previous Toxoplasma gondii studies revealed that mutations in the dhps (dihydropteroate synthase) gene are associated with resistance to sulfonamides. Although Brazilian strains are genotypically different, very limited data are available regarding the susceptibility of strains obtained from human to sulfonamides. The aim of this study was to evaluate the efficacy of sulfadiazine (SDZ) against Brazilian isolates of T. gondii and verify whether isolates present polymorphisms in the dhps gene. We also investigated whether the virulence-phenotype and/or genotype were associated with the profile of susceptibility to SDZ. Methods Five T. gondii isolates obtained from newborns with congenital toxoplasmosis were used to verify susceptibility. Mice were infected with 104 tachyzoites and orally treated with different doses of SDZ. The mortality curve was evaluated by the Log-rank test. The presence of polymorphisms in the dhps gene was verified using sequencing. A descriptive analysis for 11 Brazilian isolates was used to assess the association between susceptibility, genotype, and virulence-phenotype. Results Statistical analysis showed that TgCTBr03, 07, 08, and 16 isolates were susceptible to SDZ, whereas TgCTBr11 isolate presented a profile of resistance to SDZ. Nineteen polymorphisms were identified in dhps exons. Seven polymorphisms corresponded to non-synonymous mutations, with four being new mutations, described for the first time in this study. No association was found between the profile of susceptibility and the virulence-phenotype or genotype of the parasite. Conclusions There is a high variability in the susceptibilities of Brazilian T. gondii strains to SDZ, with evidence of drug resistance. Despite the large number of polymorphisms identified, the profile of susceptibility to SDZ was not associated with any of the dhps variants identified in this study. Other genetic factors, not yet determined, may be associated with the resistance to SDZ; thus

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

PubMed

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

2017-02-13

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. Case-control study. Cases and controls were enrolled in Durango City, Mexico. 65 patients with Parkinson's disease and 195 age- and gender-matched control subjects without Parkinson's disease. 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. 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. 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 is warranted. Published by the BMJ Publishing Group Limited. For permission to use (where not

Screening of chemical compound libraries identified new anti-Toxoplasma gondii agents.

PubMed

Adeyemi, Oluyomi Stephen; Sugi, Tatsuki; Han, Yongmei; Kato, Kentaro

2018-02-01

Toxoplasma gondii is the etiological agent of toxoplasmosis, a common parasitic disease that affects nearly one-third of the human population. The primary infection can be asymptomatic in healthy individuals but may prove fatal in immunocompromised individuals. Available treatment options for toxoplasmosis patients are limited, underscoring the urgent need to identify and develop new therapies. Non-biased screening of libraries of chemical compounds including the repurposing of well-characterized compounds is emerging as viable approach to achieving this goal. In the present investigation, we screened libraries of natural product and FDA-approved compounds to identify those that inhibited T. gondii growth. We identified 32 new compounds that potently inhibit T. gondii growth. Our findings are new and promising, and further strengthen the prospects of drug repurposing as well as the screening of a wide range of chemical compounds as a viable source of alternative anti-parasitic therapeutic agents.

Seroprevalence and correlates of Toxoplasma gondii infection in Yoremes (Mayos) in Mexico: a cross-sectional study

PubMed Central

Alvarado-Esquivel, Cosme; Rascón-Careaga, Antonio; Hernández-Tinoco, Jesús; Corella-Madueño, María Alba Guadalupe; Sánchez-Anguiano, Luis Francisco; Aldana-Madrid, María Lourdes; Almada-Balderrama, Gerardo Javier; Nuñez-Aguirre, Alan Daniel; Liesenfeld, Oliver

2016-01-01

Objectives We sought to determine the prevalence of anti-Toxoplasma gondii antibodies in Yoremes and to identify associations of T. gondii exposure with sociodemographic, clinical and behavioural characteristics of Yoremes. Design A cross-sectional survey. Setting Yoremes were enrolled in the locality of Tierra Blanca in the municipality of Navojoa in Sonora State, Mexico. Participants We studied 200 Yoremes (Mayos); they are an indigenous ethnic group living in a coastal region in northwestern Mexico. Primary and secondary outcome measures We assessed the prevalence of anti-Toxoplasma IgG and IgM antibodies in participants using enzyme-linked immunoassays. We used a standardised questionnaire to obtain the characteristics of Yoremes. The association of T. gondii exposure and Yoremes’ characteristics was assessed by bivariate and multivariate analyses. Results Of the 200 Yoremes studied (mean age: 31.50±18.43 years), 26 (13.0%) were positive for anti-T. gondii IgG antibodies and 19 (73.1%) of them were also positive for anti-T. gondii IgM antibodies. Seroprevalence of T. gondii infection did not vary with sex, educational level, occupation or socioeconomic status. In contrast, multivariate analysis of sociodemographic and behavioural characteristics showed that T. gondii exposure was associated with increasing age (OR=1.02; 95% CI 1.00 to 1.04; p=0.03) and consumption of squirrel meat (OR=4.99; 95% CI 1.07 to 23.31; p=0.04). Furthermore, seroprevalence of T. gondii infection was significantly higher in Yoremes with a history of lymphadenopathy (p=0.03) and those suffering from frequent abdominal pain (p=0.03). In women, T. gondii exposure was associated with a history of caesarean sections (p=0.03) and miscarriages (p=0.02). Conclusions We demonstrate, for the first time, serological evidence of T. gondii exposure among Yoremes in Mexico. Results suggest that infection with T. gondii might be affecting the health of Yoremes. Results may be useful for an

Toxoplasma gondii and Neospora caninum seroprevalence in dairy sheep and goats mixed stock farming.

PubMed

Diakoua, Anastasia; Anastasia, Diakou; Papadopoulos, Elias; Elias, Papadopoulos; Panousis, Nikolaos; Nikolaos, Panousis; Karatzias, Charilaos; Charilaos, Karatzias; Giadinis, Nektarios; Nektarios, Giadinis

2013-12-06

Toxoplasma and Neospora infections are important causes of abortions and economic losses in animal production. Mixed stock farming of sheep and goats is a common practice in Mediterranean countries and could serve as a suitable model for the evaluation of differences between the two animal species regarding parasitic infections. In order to investigate the seroprevalence of T. gondii and N. caninum among flocks of small ruminants in Greece and to evaluate any prevalence difference between sheep and goats kept in mixed flocks, 833 sera samples (458 sheep and 375 goats) from 50 mixed flocks in different areas of the country were examined by ELISA for the detection of specific antibodies. Specific IgG against T. gondii were detected in 53.71% and 61.3% and against N. caninum in 16.8% and 6.9% of the sheep and goats, respectively. Goats had higher Toxoplasma seroprevalence than sheep (p<0.05), while sheep had higher Neospora seroprevalence than goats (p<0.05). The present study is the first report world wide, on the seroprevalence of T. gondii and N. caninum in sheep and goats that are kept together in mixed flocks. Copyright © 2013 Elsevier B.V. All rights reserved.

Induction of dendritic cell migration upon Toxoplasma gondii infection potentiates parasite dissemination.

PubMed

Lambert, Henrik; Hitziger, Niclas; Dellacasa, Isabel; Svensson, Mattias; Barragan, Antonio

2006-10-01

The processes leading to systemic dissemination of the obligate intracellular parasite Toxoplasma gondii remain unelucidated. In vitro studies on human and murine dendritic cells (DC) revealed that active invasion of DC by Toxoplasma induces a state of hypermotility in DC, enabling transmigration of infected DC across endothelial cell monolayers in the absence of chemotactic stimuli. Infected DC exhibited upregulation of maturation markers and co-stimulatory molecules. While modulation of cell adhesion molecules CD11/CD18 was similar for Toxoplasma-infected DC and lipopolysaccharide (LPS)-matured DC, Toxoplasma-infected DC did not exhibit upregulation of CD54/ICAM-1. Induction of host cell migration in vitro required live intracellular parasite(s) and was inhibited by uncoupling the Gi-protein signalling pathway with pertussis toxin, but did not depend on CCR5, CCR7 or Toll/interleukin-1 receptor signalling. When migration of Toxoplasma-infected DC was compared with migration of LPS-stimulated DC in vivo, similar or higher numbers of Toxoplasma-infected DC reached the mesenteric lymph nodes and spleen respectively. Adoptive transfer of Toxoplasma-infected DC resulted in more rapid dissemination of parasites to distant organs and in exacerbation of infection compared with inoculation with free parasites. Altogether, these findings show that Toxoplasma is able to subvert the regulation of host cell motility and likely exploits the host's natural pathways of cellular migration for parasite dissemination.

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

USDA-ARS?s Scientific Manuscript database

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 ...

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

USDA-ARS?s Scientific Manuscript database

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...

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

USDA-ARS?s Scientific Manuscript database

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

Is Toxoplasma Gondii Infection Related to Brain and Behavior Impairments in Humans? Evidence from a Population-Representative Birth Cohort.

PubMed

Sugden, Karen; Moffitt, Terrie E; Pinto, Lauriane; Poulton, Richie; Williams, Benjamin S; Caspi, Avshalom

2016-01-01

Toxoplasma gondii (T. gondii) is a protozoan parasite present in around a third of the human population. Infected individuals are commonly asymptomatic, though recent reports have suggested that infection might influence aspects of the host's behavior. In particular, Toxoplasma infection has been linked to schizophrenia, suicide attempt, differences in aspects of personality and poorer neurocognitive performance. However, these studies are often conducted in clinical samples or convenience samples. In a population-representative birth-cohort of individuals tested for presence of antibodies to T. gondii (N = 837) we investigated the association between infection and four facets of human behavior: neuropsychiatric disorder (schizophrenia and major depression), poor impulse control (suicidal behavior and criminality), personality, and neurocognitive performance. Suicide attempt was marginally more frequent among individuals with T. gondii seropositivity (p = .06). Seropositive individuals also performed worse on one out of 14 measures of neuropsychological function. On the whole, there was little evidence that T. gondii was related to increased risk of psychiatric disorder, poor impulse control, personality aberrations or neurocognitive impairment.

Is Toxoplasma Gondii Infection Related to Brain and Behavior Impairments in Humans? Evidence from a Population-Representative Birth Cohort

PubMed Central

Sugden, Karen; Moffitt, Terrie E.; Pinto, Lauriane; Poulton, Richie; Williams, Benjamin S.; Caspi, Avshalom

2016-01-01

Background Toxoplasma gondii (T. gondii) is a protozoan parasite present in around a third of the human population. Infected individuals are commonly asymptomatic, though recent reports have suggested that infection might influence aspects of the host’s behavior. In particular, Toxoplasma infection has been linked to schizophrenia, suicide attempt, differences in aspects of personality and poorer neurocognitive performance. However, these studies are often conducted in clinical samples or convenience samples. Methods/Results In a population-representative birth-cohort of individuals tested for presence of antibodies to T. gondii (N = 837) we investigated the association between infection and four facets of human behavior: neuropsychiatric disorder (schizophrenia and major depression), poor impulse control (suicidal behavior and criminality), personality, and neurocognitive performance. Suicide attempt was marginally more frequent among individuals with T. gondii seropositivity (p = .06). Seropositive individuals also performed worse on one out of 14 measures of neuropsychological function. Conclusion On the whole, there was little evidence that T. gondii was related to increased risk of psychiatric disorder, poor impulse control, personality aberrations or neurocognitive impairment. PMID:26886853

A role of carboxy-terminal region of Toxoplasma gondii-heat shock protein 70 in enhancement of T. gondii infection in mice

PubMed Central

Mun, Hye-Seong; Norose, Kazumi; Aosai, Fumie; Chen, Mei

2000-01-01

We investigated the role of recombinant Toxoplasma gondii heat shock protein (rT.g.HSP) 70-full length, rT.g.HSP70-NH2-terminal region, or rT.g.HSP70-carboxy-terminal region in prophylactic immunity in C57BL/6 mice perorally infected with Fukaya cysts of T. gondii. At 3, 4, 5, and 6 weeks after infection, the number of T. gondii in the brain tissue of each mouse was measured by quantitative competitive-polymerase chain reaction (QC-PCR) targeting the surface antigen (SAG) 1 gene. Immunization with rT.g.HSP70-full length or rT.g.HSP70-carboxy-terminal region increased the number of T.gondii in the brain tissue after T. gondii infection, whereas immunization with rT.g.HSP70-NH2-terminal region did not. These results suggest that T.g.HSP70-carboxy-terminal region as well as T.g.HSP70-full length may induce deleterious effects on the protective immunity of mice infected with a cyst-forming T. gondii strain, Fukaya. PMID:10905074

Biological and molecular characterizations of Toxoplasma gondii strains obtained from Southern sea otters (Enhydra lutris nereis)

USGS Publications Warehouse

Cole, Rebecca 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.

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.

Detection of Human Toxoplasma-Specific Immunoglobulins A, M, and G with a Recombinant Toxoplasma gondii Rop2 Protein

PubMed Central

Martin, Valentina; Arcavi, Miriam; Santillan, Graciela; Amendoeira, Maria Regina R.; De Souza Neves, Elizabeth; Griemberg, Gloria; Guarnera, Eduardo; Garberi, Juan C.; Angel, Sergio O.

1998-01-01

The Toxoplasma gondii rhoptry protein Rop2 was expressed in Escherichia coli as a fusion protein containing 44 kDa of the 55-kDa mature Rop2, supplied with six histidyl residues at the N-terminal end (Rop2196–561). Humoral response during Toxoplasma infection of humans was analyzed by immunoglobulin G (IgG), IgA, and IgM enzyme-linked immunosorbent assay with Rop2196–561 as the antigen substrate. The analyzed sera were divided according to T. gondii-specific serological tests (IgG, IgA, or IgM indirect immunofluorescence and IgA or IgM immunosorbent agglutination assay) as group A (IgG+ IgA− IgM−; n = 35), group B (IgG+ IgA+ IgM+; n = 21), group C (IgG+ IgA+ IgM−; n = 5), and group D (IgG+ IgA− IgM+; n = 16). Twenty-six T. gondii-seronegative sera from individuals with other infections were also included (group E). Anti-Rop2 IgG antibodies were detected in 82.8% of group A sera and in 97.6% of the sera with acute-phase marker immunoglobulins (groups B, C, and D). The percentage of IgA antibody reactivity against Rop2196–561 was 17.1% in group A, 50% in group D, and 80.8% in groups B and C. The percentage of IgM antibody reactivity was 0% in groups A and C and 62% in groups B and D. Sera from group E failed to show IgA, IgM, or IgG antibody reactivity. Since T. gondii Rop2 elicits a strong humoral response from an early stage of infection, it is suggested that recombinant Rop2196–561 would be suitable for use in diagnostic systems, in combination with other T. gondii antigens, to detect specific IgG, IgA, and IgM antibodies. PMID:9729528

DNA Amplification Techniques for the Detection of Toxoplasma gondii Tissue Cysts in Meat Producing Animals: A Narrative Review Article

PubMed Central

RIAZ, Farooq; RASHID, Imran; AKBAR, Haroon; SHEHZAD, Wasim; ISLAM, Saher; BAJWA, Amna Arshad; SAEED, Khalid; ASHRAF, Kamran

2016-01-01

Background: Toxoplasma gondii is an intracellular parasite, which infects one-third population of world. Humans and animals acquire infection by ingesting oocytes from feces of cats or by meat of other animals having cysts that may lead to congenital, ocular or cephalic toxoplasmosis. Either it is important to detect T. gondii from meat of food animals from retail shops or directly at slaughterhouses, which is meant for export. Methods: The current research was done without time limitation using such terms as follows: “Toxoplasma gondii”, “Meat”, “Tissue cyst”, “PCR”, “LAMP”, “Screening” and “Immunological assay” alone or in combination, in English language. The used electronic databases for searching included as follows: Pub-Med, Scopus, Google Scholar, Web of Science and Science Direct. The searches were limited to the published papers to English language. Results: Sensitivity of different molecular techniques for diagnosis of Toxoplasma is real-time PCR > LAMP > conventional PCR. In addition to these DNA analysis tools, bioassay in mice and cats is considered as “gold standard” to detect T. gondii. Conclusion: This review article will help the readers for grasping advantages and limitations of different diagnostic tools for screening meat samples for T. gondii. This review also makes bibliography about the type of meat sample to be processed for diagnosis and different primers or sequences to be targeted for T. gondii by number of researches for its detection from meat or tissue sample using DNA amplification techniques. PMID:28127354

Decreased seroprevalence for Toxoplasma gondii in Seventh Day Adventists in Maryland.

PubMed

Roghmann, M C; Faulkner, C T; Lefkowitz, A; Patton, S; Zimmerman, J; Morris, J G

1999-05-01

Despite its widespread prevalence, uncertainties remain about the relative contribution of various routes of transmission to the overall rate of infection with Toxoplasma gondii, particularly in developed countries. To explore the hypothesis that meat consumption is an important risk factor for infection, a cross-sectional seroprevalence study was performed on healthy adults in one region in the state of Maryland. The population included Seventh Day Adventists who as a group follow a diet containing no meat, and control community volunteers who were not Seventh Day Adventists. Thirty-one percent of the population had serologic evidence of T. gondii infection. People with T. gondii infection were older (49 versus 42 years old; P < 0.01, by t-test) and less likely to be Seventh Day Adventists (24% versus 50%; P < 0.01, by chi-square test) than people without T. gondii infection. When adjustments were made for age and gender through multiple logistic regression, Seventh Day Adventists had a significantly decreased risk of T. gondii infection (odds ratio = 0.21, 95% confidence interval = 0.09-0.46, P = 0.0001) compared with the controls. While the basis for this effect remains to be determined, one possible protective factor is the general adherence of Seventh Day Adventists to a diet that does not contain meat.

Quantifying the risk of human Toxoplasma gondii infection due to consumption of domestically-produced lamb in the United States

USDA-ARS?s Scientific Manuscript database

Toxoplasma gondii is a widely prevalent protozoan parasite worldwide. Human toxoplasmosis is responsible for considerable morbidity and mortality in the United States. Meat products have been identified as an important source of T. gondii infections in humans. The goal of this study was to develop a...

Seroprevalence of Toxoplasma gondii in mainland and sub-Antarctic New Zealand sea lion (Phocarctos hookeri) populations.

PubMed

Michael, S A; Howe, L; Chilvers, B L; Morel, Pch; Roe, W D

2016-09-01

To investigate the seroprevalence of antibodies to Toxoplasma gondii in New Zealand sea lions (Phocarctos hookeri), as a potential contributor to reproductive failure. Archived sera were sourced from New Zealand sea lions from two recolonising mainland populations in the Otago Peninsula (n=15) and Stewart Island (n=12), as well as a declining population at Enderby Island (n=28) in the New Zealand sub-Antarctic. Sera were tested for antibodies to T. gondii using a commercially available ELISA (with samples considered positive if the sample to positive ratio was >30%), and latex agglutination test (LAT; with titres ≥1:32 considered positive). Western blot analysis was used to validate the results of a subset of 14 samples. Five samples from sea lions in mainland locations were confirmed positive for antibodies to T. gondii. Two adult females exhibited high LAT antibody titres (min 1:2048, max 1:4096) on both occasions when sampled 1 and 2 years apart, respectively. No animals from Enderby Island were seropositive. Toxoplasma gondii infection is unlikely to be a major contributor to poor reproductive success in New Zealand sea lions. However, continued surveillance is pertinent to assess subclinical and clinical impacts of the parasite on these threatened populations. The commercial tests evaluated here, with further species-specific threshold refinement could provide a fast, inexpensive and reliable indicator of T. gondii exposure in New Zealand sea lions.

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

USDA-ARS?s Scientific Manuscript database

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...

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

PubMed Central

Lima, Tatiane S.; Gov, Lanny

2018-01-01

ABSTRACT Neutrophils are a major player in host immunity to infection; however, the mechanisms by which human neutrophils respond to the intracellular protozoan parasite Toxoplasma gondii are still poorly understood. In the current study, we found that, whereas primary human monocytes produced interleukin-1beta (IL-1β) in response to T. gondii infection, human neutrophils from the same blood donors did not. Moreover, T. gondii inhibited lipopolysaccharide (LPS)-induced IL-1β synthesis in human peripheral blood neutrophils. IL-1β suppression required active parasite invasion, since heat-killed or mycalolide B-treated parasites did not inhibit IL-1β release. By investigating the mechanisms involved in this process, we found that T. gondii infection of neutrophils treated with LPS resulted in reduced transcript levels of IL-1β and NLRP3 and reduced protein levels of pro-IL-1β, mature IL-1β, and the inflammasome sensor NLRP3. In T. gondii-infected neutrophils stimulated with LPS, the levels of MyD88, TRAF6, IKKα, IKKβ, and phosphorylated IKKα/β were not affected. However, LPS-induced IκBα degradation and p65 phosphorylation were reduced in T. gondii-infected neutrophils, and degradation of IκBα was reversed by treatment with the proteasome inhibitor MG-132. Finally, we observed that T. gondii inhibited the cleavage and activity of caspase-1 in human neutrophils. These results indicate that T. gondii suppression of IL-1β involves a two-pronged strategy whereby T. gondii inhibits both NF-κB signaling and activation of the NLRP3 inflammasome. These findings represent a novel mechanism of T. gondii evasion of human neutrophil-mediated host defense by targeting the production of IL-1β. PMID:29440572

Anti-Gluten Immune Response following Toxoplasma gondii Infection in Mice

PubMed Central

Severance, Emily G.; Kannan, Geetha; Gressitt, Kristin L.; Xiao, Jianchun; Alaedini, Armin; Pletnikov, Mikhail V.; Yolken, Robert H.

2012-01-01

Gluten sensitivity may affect disease pathogenesis in a subset of individuals who have schizophrenia, bipolar disorder or autism. Exposure to Toxoplasma gondii is a known risk factor for the development of schizophrenia, presumably through a direct pathological effect of the parasite on brain and behavior. A co-association of antibodies to wheat gluten and to T. gondii in individuals with schizophrenia was recently uncovered, suggesting a coordinated gastrointestinal means by which T. gondii and dietary gluten might generate an immune response. Here, we evaluated the connection between these infectious- and food-based antigens in mouse models. BALB/c mice receiving a standard wheat-based rodent chow were infected with T. gondii via intraperitoneal, peroral and prenatal exposure methods. Significant increases in the levels of anti-gluten IgG were documented in all infected mice and in offspring from chronically infected dams compared to uninfected controls (repetitive measures ANOVAs, two-tailed t-tests, all p≤0.00001). Activation of the complement system accompanied this immune response (p≤0.002–0.00001). Perorally-infected females showed higher levels of anti-gluten IgG than males (p≤0.009) indicating that T. gondii-generated gastrointestinal infection led to a significant anti-gluten immune response in a sex-dependent manner. These findings support a gastrointestinal basis by which two risk factors for schizophrenia, T. gondii infection and sensitivity to dietary gluten, might be connected to produce the immune activation that is becoming an increasingly recognized pathology of psychiatric disorders. PMID:23209841

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.

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. Published by Elsevier B.V.

Antibodies to Toxoplasma gondii in patients with schizophrenia: a meta-analysis.

PubMed

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

2007-05-01

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.

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.

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

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

USDA-ARS?s Scientific Manuscript database

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...

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

USDA-ARS?s Scientific Manuscript database

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...

Isolation and RFLP genotyping of Toxoplasma gondii from the gray wolf (Canis lupus).

PubMed

Dubey, J P; Choudhary, S; Ferreira, L R; Kwok, O C H; Butler, E; Carstensen, M; Yu, L; Su, C

2013-11-08

Little is known of the genetic diversity of Toxoplasma gondii circulating in wildlife. In the present study feral gray wolves (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 (cut-off titer of 25). Tissues (hearts, brains or both) of 109 wolves were bioassayed in mice for protozoal isolation. Viable T. gondii was isolated from 25 and the isolates were further propagated in cell culture. T. gondii DNA from these isolates was characterized using 10 PCR-RFLP markers (SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1 and Apico). Four genotypes were detected. Twenty-one isolates were Type 12 (ToxoDB PCR-RFLP genotype #5), 2 were Type II clonal (ToxoDB #1), 1 was Type II variant (ToxoDB #3), and 1 was a new genotype designated as ToxoDB genotype #219. Published by Elsevier B.V.

Seroprevalence of Toxoplasma gondii in wild boars, red deer and roe deer in Poland

PubMed Central

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. PMID:25993468

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. © L. Witkowski et al., published by EDP Sciences, 2015.

Acute Toxoplasma gondii infection in children with reactive hyperplasia of the cervical lymph nodes.

PubMed

Bilal, Jalal A; Alsammani, Mohamed A; Ahmed, Mohamed I

2014-07-01

To determine the seroprevalence of Toxoplasma gondii (T. gondii) in children with reactive hyperplasia of the cervical lymph nodes. This cross-sectional prospective study was conducted in Khartoum Children Emergency Hospital, Khartoum, Sudan between January 2010 and April 2011. Eighty children with cervical lymphadenopathy were selected using random sampling. Their lymph nodes were aspirated for cytology, and a blood sample was collected from all patients for routine laboratory analysis and T. gondii IgG and IgM antibodies. Among 80 children with cervical lymphadenopathy, 60 (75%) had non-specific reactive hyperplasia. The seroprevalence of T. gondii among children with cervical lymphadenopathy was 27.5% (n=22), and the seropositivity of acute T. gondii among those with reactive hyperplasia was 36.7% (n=22/60). Lymph nodes in the T. gondii positive group were mobile and warm (p<0.05). The clinical features and laboratory tests were insignificant predictors of acute T. gondii infection with reactive hyperplasia of the cervical lymph nodes. The prevalence of acute T. gondii infection is high among children with non-specific reactive hyperplasia of the cervical lymph nodes. Routine laboratory studies are not helpful in the diagnosis of T. gondii infection with reactive hyperplasia of the lymph nodes however, serological studies may be requested prior to invasive procedures.

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

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

USDA-ARS?s Scientific Manuscript database

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 (...

Seroprevalence of Toxoplasma gondii in free-ranging and feral cats on Amami Oshima Island, Japan.

PubMed

Matsuu, Aya; Yokota, Shin-Ichi; Ito, Keiko; Masatani, Tatsunori

2017-11-17

On Amami Oshima Island, free-ranging and feral cats are harmful to wildlife populations. In this study, the seroprevalence of Toxoplasma gondii in these cats was examined using a newly developed Gaussia luciferase immunoprecipitation system assay. Of 1,363 cats, 123 cats (9.0%) was positive for T. gondii. The prevalence was significantly different in different areas; among cats in the rural area, where many wild animals live, including endangered species, T. gondii infection was more prevalent than in the urban area of the island. This finding indicates a possible risk to wildlife of infection from free-ranging and feral cats. Therefore, management of cats is important for wildlife conservation.

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

USDA-ARS?s Scientific Manuscript database

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 ...

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.

Effects of Monovalent and Divalent Salt Solutions on the Transport of Toxoplasma gondii in Saturated Porous Media

NASA Astrophysics Data System (ADS)

Darnault, C. J. G.; Pullano, C. P.; Mutty, T.; L'Ollivier, C.; Dubey, J. P.; Dumetre, A.

2017-12-01

The pathogenic microorganism Toxoplasma gondii is a current public health threat. Knowledge of the fate and transport of T. gondii in the environment, especially the subsurface, is critical to evaluate the risk of soil and groundwater contaminations. The physico-chemcial properties of groundwater systems, i.e. solution chemistry and aquifer materials, play a key role in the interaction of biocolloids with surfaces and therefore their mobility. This research examines how different salt solutions alter the mobility of T. gondii through saturated porous media. Salt solutions containing varying ionic strengths and concentrations of sodium chloride, calcium chloride, and magnesium chloride were used to test the transport of the T. gondii oocysts. These tests were performed using quartz silica sand columns fed by a peristaltic pump in order to generate flow and transport of the biocolloids. The salt solution was pumped though the column followed by a pulse of the T. gondii oocysts, then a pulse of salt solution without oocysts, and then lastly a pulse of distilled water. Sampling of the solution exiting the columns was tested for T. gondii oocysts using qPCR in order to quantify the oocysts present. The breakthough curve results were then compared to a conservative bromide tracer test in order to determine the factors associated with the movement of these biocolloids through the sand columns. A model of the flow of the toxoplasma colloids through the sand matrix was made in order to characterize the parameters affecting the transport and retention of T. gondii occysts though saturated porous media.

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.

Neospora caninum and Toxoplasma gondii antibodies in dogs from Durango City, Mexico.

PubMed

Dubey, J P; Alvarado-Esquivel, C; Liesenfeld, O; Herrera-Flores, R G; Ramírez-Sánchez, B E; González-Herrera, A; Martínez-García, S A; Bandini, L A; Kwok, O C H

2007-10-01