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Sample records for posterior por toxoplasma

  1. 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...

  2. Toxoplasmosis (Toxoplasma infection) Treatment

    MedlinePlus

    ... The CDC Cancel Submit Search The CDC Parasites - Toxoplasmosis (Toxoplasma infection) Note: Javascript is disabled or is ... message, please visit this page: About CDC.gov . Toxoplasmosis General Information Toxoplasmosis FAQs Toxoplasmosis & Pregnancy FAQs Epidemiology & ...

  3. Toxoplasmosis (Toxoplasma infection) Disease Symptoms

    MedlinePlus

    ... Toxoplasma infection can result from congenital infection or infection after birth by any of the modes of transmission discussed on the epidemiology and risk factors page. Eye lesions from congenital ...

  4. Posterior scleritis.

    PubMed

    Benson, W E

    1988-01-01

    Posterior scleritis must be considered in the differential diagnosis of many ocular conditions, including angle closure glaucoma, choroidal folds, optic disk edema, circumscribed fundus mass, choroidal detachment, and exudative retinal detachment. Because it is rare, a high index of suspicion is necessary. Anterior scleritis, pain, or a history of collagen-vascular disease, when present, help to alert the clinician to the correct diagnosis. Posterior scleritis affects women more often than men, but annular ciliochoroidal effusion and choroidal folds are more common in men. Exudative macular detachment and a circumscribed fundus mass are more common in women. This paper reviews the world literature on posterior scleritis and describes findings in a series of 43 patients seen at Wills Eye Hospital. It stresses the clinical features and ancillary diagnostic tests that help to establish the diagnosis.

  5. Toxoplasma gondii and Schizophrenia

    PubMed Central

    Yolken, Robert H.

    2003-01-01

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

  6. Lytic Cycle of Toxoplasma gondii

    PubMed Central

    Black, Michael W.; Boothroyd, John C.

    2000-01-01

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

  7. [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.

  8. Toxoplasma gondii proteomics

    PubMed Central

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

    2009-01-01

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

  9. Salicylanilide inhibitors of Toxoplasma gondii

    USDA-ARS?s Scientific Manuscript database

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

  10. Toxoplasma, or the discovery of a heterophage.

    PubMed

    Coppens, Isabelle

    2014-10-01

    In mammalian cells, the protozoan pathogen Toxoplasma resides in a nonfusiogenic vacuole that segregates it from host cell resources. How the parasite acquires nutrients and whether it is capable of internalizing host macromolecules have been long-standing mysteries. By exploiting a mutant of Toxoplasma lacking the cathepsin protease L, Dou et al. observed the accumulation of host cytosolic-derived proteins in a multivesicular post-Golgi compartment, which establishes the existence of a functional heterophagic pathway in Toxoplasma.

  11. The Toxoplasma gondii oocyst from cat feces.

    PubMed

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

    1970-10-01

    Coccidian oocysts resembling those of Isospora bigemina were excreted by cats fed Toxoplasma. In order to identify these oocysts with Toxoplasma infectivity a number of critical comparisons were made. The appearance of oocysts and Toxoplasma infectivity was simultaneous in the feces of 23 of 24 adult cats, 3-5 days after feeding of Toxoplasma cysts; in the feces of 4 out of 9 cats, 7-10 days after feeding of trophozoites; and in 8 out of 17 cats, 20-24 days after feeding of cat feces containing oocysts. Oocysts and infectivity were present in similar numbers, and they disappeared simultaneously from the feces of cats. Oocysts and infectivity were also observed simultaneously in the feces of 9 kittens, 1-2 days old, fed Toxoplasma cysts. Oocysts could not be separated from infectivity by filtration, by continuous particle electrophoresis, or by density gradient centrifugation. Excystation of oocysts was followed by an increase in titer of Toxoplasma infectivity. Unsporulated oocysts in fresh cat feces were noninfectious to mice, but oocyst sporulation was associated quantitatively with the development of infectivity at different temperatures and conditions of oxygenation. Maximum oocyst sporulation at 48 hr correlated with the development of maximum Toxoplasma infectivity. 1 and 2% sulfuric acid, and 2.5% potassium dichromate were found to be the best preservatives for sporulation of oocysts and for the development of Toxoplasma infectivity. Low sporulation rates in 0.1% formalin, 20% ethanol, and in water were associated with low infectivity in these reagents. Neither Toxoplasma infectivity nor oocysts developed in 0.3% formalin, 1% ammonium hydroxide, or 1% iodine in 20% ethanol. Oocysts, sporocysts, and sporozoites were stained specifically with Toxoplasma antibody in the indirect fluorescent antibody test. Typical coccidian stages, schizonts, and male and female gametocytes were found in the epithelium of the small intestine of kittens fed Toxoplasma cysts. The

  12. THE TOXOPLASMA GONDII OOCYST FROM CAT FECES

    PubMed Central

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

    1970-01-01

    Coccidian oocysts resembling those of Isospora bigemina were excreted by cats fed Toxoplasma. In order to identify these oocysts with Toxoplasma infectivity a number of critical comparisons were made. The appearance of oocysts and Toxoplasma infectivity was simultaneous in the feces of 23 of 24 adult cats, 3–5 days after feeding of Toxoplasma cysts; in the feces of 4 out of 9 cats, 7–10 days after feeding of trophozoites; and in 8 out of 17 cats, 20–24 days after feeding of cat feces containing oocysts. Oocysts and infectivity were present in similar numbers, and they disappeared simultaneously from the feces of cats. Oocysts and infectivity were also observed simultaneously in the feces of 9 kittens, 1–2 days old, fed Toxoplasma cysts. Oocysts could not be separated from infectivity by filtration, by continuous particle electrophoresis, or by density gradient centrifugation. Excystation of oocysts was followed by an increase in titer of Toxoplasma infectivity. Unsporulated oocysts in fresh cat feces were noninfectious to mice, but oocyst sporulation was associated quantitatively with the development of infectivity at different temperatures and conditions of oxygenation. Maximum oocyst sporulation at 48 hr correlated with the development of maximum Toxoplasma infectivity. 1 and 2% sulfuric acid, and 2.5% potassium dichromate were found to be the best preservatives for sporulation of oocysts and for the development of Toxoplasma infectivity. Low sporulation rates in 0.1% formalin, 20% ethanol, and in water were associated with low infectivity in these reagents. Neither Toxoplasma infectivity nor oocysts developed in 0.3% formalin, 1% ammonium hydroxide, or 1% iodine in 20% ethanol. Oocysts, sporocysts, and sporozoites were stained specifically with Toxoplasma antibody in the indirect fluorescent antibody test. Typical coccidian stages, schizonts, and male and female gametocytes were found in the epithelium of the small intestine of kittens fed Toxoplasma

  13. Posterior ankle impingement.

    PubMed

    Giannini, Sandro; Buda, Roberto; Mosca, Massimiliano; Parma, Alessandro; Di Caprio, Francesco

    2013-03-01

    Posterior ankle impingement is a common cause of chronic ankle pain and results from compression of bony or soft tissue structures during ankle plantar flexion. Bony impingement is most commonly related to an os trigonum or prominent trigonal process. Posteromedial soft tissue impingement generally arises from an inversion injury, with compression of the posterior tibiotalar ligament between the medial malleolus and talus. Posterolateral soft tissue impingement is caused by an accessory ligament, the posterior intermalleolar ligament, which spans the posterior ankle between the posterior tibiofibular and posterior talofibular ligaments. Finally, anomalous muscles have also been described as a cause of posterior impingement.

  14. Kinematic analysis of Toxoplasma gondii motility.

    PubMed

    Frixione, E; Mondragón, R; Meza, I

    1996-01-01

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

  15. Cathepsin proteases in Toxoplasma gondii

    PubMed Central

    Dou, Zhicheng; Carruthers, Vern B.

    2014-01-01

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

  16. [Progress in transgenics on Toxoplasma gondii].

    PubMed

    Zhang, Yan-Lei; Zhang, Hou-Shuang; Zhou, Jin-Lin

    2011-12-01

    The application of transgenes in Toxoplasma gondii research facilitates its genetic analysis. This article reviews the progress in construction of transgenes vector, transgenics in the research of T. gondii.

  17. Presumptive Toxoplasma gondii abortion in a sheep

    PubMed Central

    Weissmann, Judith

    2003-01-01

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

  18. Percutaneous Posterior Calcaneal Osteotomy.

    PubMed

    Lui, Tun Hing

    2015-01-01

    Different types of posterior calcaneal osteotomy are used for calcaneal realignment in the management of hindfoot deformity. We describe a percutaneous technique of posterior calcaneal osteotomy that can be either a Dwyer-type closing wedge osteotomy or displacement osteotomy.

  19. 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

  20. Salicylanilide inhibitors of Toxoplasma gondii.

    PubMed

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

    2012-10-11

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

  1. Toxoplasma

    EPA Science Inventory

    T. gondii is an obligate intracellular protozoan parasite that can infect all warm blooded animals ranging from: humans, pets, livestock, to marine aquatic animals. The definitive host is the feline species (both domestic and wild cats), where the sexual stage of the life cycle o...

  2. Toxoplasma

    EPA Science Inventory

    T. gondii is an obligate intracellular protozoan parasite that can infect all warm blooded animals ranging from: humans, pets, livestock, to marine aquatic animals. The definitive host is the feline species (both domestic and wild cats), where the sexual stage of the life cycle o...

  3. Effects of Toxoplasma on Human Behavior

    PubMed Central

    Flegr, Jaroslav

    2007-01-01

    Although latent infection with Toxoplasma gondii is among the most prevalent of human infections, it has been generally assumed that, except for congenital transmission, it is asymptomatic. The demonstration that latent Toxoplasma infections can alter behavior in rodents has led to a reconsideration of this assumption. When infected human adults were compared with uninfected adults on personality questionnaires or on a panel of behavioral tests, several differences were found. Other studies have demonstrated reduced psychomotor performance in affected individuals. Possible mechanisms by which T. gondii may affect human behavior include its effect on dopamine and on testosterone. PMID:17218612

  4. Effects of toxoplasma on human behavior.

    PubMed

    Flegr, Jaroslav

    2007-05-01

    Although latent infection with Toxoplasma gondii is among the most prevalent of human infections, it has been generally assumed that, except for congenital transmission, it is asymptomatic. The demonstration that latent Toxoplasma infections can alter behavior in rodents has led to a reconsideration of this assumption. When infected human adults were compared with uninfected adults on personality questionnaires or on a panel of behavioral tests, several differences were found. Other studies have demonstrated reduced psychomotor performance in affected individuals. Possible mechanisms by which T. gondii may affect human behavior include its effect on dopamine and on testosterone.

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

    PubMed

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

    1979-01-01

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

  6. Purine metabolism in Toxoplasma gondii

    SciTech Connect

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

    1989-06-25

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

  7. 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 ...

  8. 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...

  9. 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 ...

  10. Macrophages as a Battleground for Toxoplasma Pathogenesis

    PubMed Central

    Murray, Peter J.

    2011-01-01

    Summary sentence In this issue of Cell Host & Microbe, Jensen et al. show clonal lineages of Toxoplasma gondii have evolved distinct ways of subverting their favored host cell, the macrophage. The results suggest that T. gondii and the ROP kinases can be used to probe immune signaling pathways. PMID:21669391

  11. Toxoplasma: guess who's coming to dinner.

    PubMed

    Gruenberg, Jean; van der Goot, F Gisou

    2006-04-21

    In this issue of Cell, Coppens and coworkers (Coppens et al., 2006) describe how Toxoplasma gondii, an obligate intracellular parasite, feeds on the host. Coppens et al. provide evidence that the parasite takes host cell endosomes and lysosomes hostage by sequestering them where the parasite resides, within invaginations of the parasitophorous vacuole.

  12. Toxoplasma gondii in Costa Rican cats.

    PubMed

    Ruiz, A; Frenkel, J K

    1980-11-01

    Toxoplasma gondii infection of cats was studied in seven localities in Costa Rica. A total of 237 cats were tested for antibody by the dye test, and for oocysts by injection into mice. Toxoplasma was isolated from 55 (23%) and antibody was found in 109 (46%). Sixty percent of cats were infected as shown by shedding or antibody. Of the 55 isolations, 64% were from kittens without antibody and 36% from kittens with antibody. Almost half of the Toxoplasma isolations were made from the feces of kittens weighing less than 600 g, 35 cm in length, or under 2 months of age, of which 41% were shedding Toxoplasma. Six hundred and seventy-six homeowners in the seven towns were questioned about the number of owned and stray cats visiting their houses, the cats' pattern of roaming, food sources, types of food foraged, defecation sites outdoors and indoors, and location of fecal deposits in houses. Seventy-six percent of houses reported cats, which averaged 2.1 cats per house; about 80% were strays, and 99% lived outdoors part or all of the time. The cats visited from 5-12 (average 6) houses, foraging for food in garbage, hunting mice, rats, sparrows and insects. Of the 516 households reporting cats, 29% supplied some food in addition. In 14% of these houses cats defecated in the house, including the false attic and crawl space; they commonly defecated in front and backyards of houses, close to human habitation and accessible to intermediate hosts.

  13. Acidocalcisomes in Toxoplasma gondii tachyzoites.

    PubMed Central

    Moreno, S N; Zhong, L

    1996-01-01

    Toxoplasma gondii tachyzoites were loaded with the fluorescent indicator fura 2 to investigate the transport mechanisms involved in maintaining their intracellular Ca2+ homoeostasis. The mitochondrial ATPase inhibitor oligomycin and the endoplasmic-reticulum Ca(2+)-ATPase inhibitor thapsigargin increased the intracellular Ca2+ concentration ([Ca2+]i), thus indicating the requirement for ATP and the involvement of the endoplasmic reticulum in maintaining intracellular Ca2+ homoeostasis. The effect of thapsigargin was more accentuated in the presence of extracellular Ca2+, clearly showing that, as occurs with other eukaryotic cells, depletion of intracellular Ca2+ pools led to an increase in the uptake of Ca2+ from the extracellular medium. In addition to these results, we found evidence that, in contrast with what occurs in mammalian cells, T. gondii tachyzoites possess a significant amount of Ca2+ stored in an acidic compartment, termed the acidocalcisome, as indicated by: (1) the increase in [Ca2+]i induced by bafilomycin A1 (a specific inhibitor of H(+)-ATPases), nigericin (a K+/H+ exchanger) or the weak base NH4Cl, in the nominal absence of extracellular Ca2+ to preclude Ca2+ entry; and (2) the effect of ionomycin, a Ca(2+)-releasing ionophore that cannot take Ca2+ out of acidic organelles and that was more effective after alkalinization of these compartments by addition of bafilomycin A1, nigericin or NH4Cl. Considering the relative importance of the ionomycin-releasable and the ionomycin + NH4Cl-releasable Ca2+ pools, it is apparent that T. gondii tachyzoites contain a significant amount of Ca2+ stored in acidocalcisomes. PMID:8573106

  14. Posterior ankle impingement syndrome.

    PubMed

    Maquirriain, Javier

    2005-10-01

    Posterior ankle impingement syndrome is a clinical disorder characterized by posterior ankle pain that occurs in forced plantar flexion. The pain may be acute as a result of trauma or chronic from repetitive stress. Pathology of the os trigonum-talar process is the most common cause of this syndrome, but it also may result from flexor hallucis longus tenosynovitis, ankle osteochondritis, subtalar joint disease, and fracture. Patients usually report chronic or recurrent posterior ankle pain caused or exacerbated by forced plantar flexion or push-off maneuvers, such as may occur during dancing, kicking, or downhill running. Diagnosis of posterior ankle impingement syndrome is based primarily on clinical history and physical examination. Radiography, scintigraphy, computed tomography, and magnetic resonance imaging depict associated bone and soft-tissue abnormalities. Symptoms typically improve with nonsurgical management, but surgery may be required in refractory cases.

  15. Posterior Cruciate Ligament Injury

    MedlinePlus

    ... tear. Contact sports. Athletes in sports such as football and soccer can tear their posterior cruciate ligament ... vehicle accident and participating in sports such as football and soccer are the most common risk factors ...

  16. Experimental Models of Ocular Infection with Toxoplasma Gondii

    PubMed Central

    Dukaczewska, Agata; Tedesco, Roberto; Liesenfeld, Oliver

    2015-01-01

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

  17. Experimental Models of Ocular Infection with Toxoplasma Gondii.

    PubMed

    Dukaczewska, Agata; Tedesco, Roberto; Liesenfeld, Oliver

    2015-12-01

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

  18. Pathology of Toxoplasma myocarditis in acquired immunodeficiency syndrome.

    PubMed

    Sahasrabudhe, Neil S; Jadhav, M V; Deshmukh, S D; Holla, V V

    2003-10-01

    Involvement of the myocardium by Toxoplasma gondii is seen in patients of acquired immunodeficiency syndrome (AIDS), mostly in association with toxoplasma encephalitis. Only few patients die as a direct result of cardiac dysfunction. Clinico-pathological findings of three cases of toxoplasma myocarditis are reported, one of which presented and died due to massive pericardial effusion. All cases showed diffuse myocarditis with parasites on histopathological examination. Incidence of toxoplasma myocarditis in patients dying with AIDS was 8.3% (3 out of 36 cases).

  19. Toxoplasma peritonitis in a patient with acquired immunodeficiency syndrome.

    PubMed

    Israelski, D M; Skowron, G; Leventhal, J P; Long, I; Blankenship, C F; Barrio, G W; Prince, J B; Araujo, F G; Remington, J S

    1988-07-01

    Toxoplasma gondii was identified in a stained slide preparation of, and isolated from, peritoneal fluid specimens obtained from a patient with the acquired immunodeficiency syndrome (AIDS). At the time of admission to the hospital, the patient's serologic tests were positive for Toxoplasma. Toxoplasma was isolated from samples of the patient's blood by mouse inoculation. Findings of newly developed methods for diagnosis of the presence of T gondii in body fluids by assay for Toxoplasma-specific antigen and by use of a DNA probe were positive.

  20. 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

  1. Mechanisms of Toxoplasma gondii persistence and latency

    PubMed Central

    Sullivan, William J.; Jeffers, Victoria

    2011-01-01

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

  2. The tibialis posterior tendon.

    PubMed

    Lhoste-Trouilloud, A

    2012-02-01

    The tibialis posterior tendon is the largest and anteriormost tendon in the medial ankle. It produces plantar flexion and supination of the ankle and stabilizes the plantar vault. Sonographic assessment of this tendon is done with high-frequency, linear-array transducers; an optimal examination requires transverse retromalleolar, longitudinal retromalleolar, and distal longitudinal scans, as well as dynamic studies. Disorders of the posterior tibial tendon include chronic tendinopathy with progressive rupture, tenosynovitis, acute rupture, dislocation and instability, enthesopathies. The most common lesion is a progressive "chewing gum" lesion that develops in a setting of chronic tendinopathy; it is usually seen in overweight women over 50 years of age with valgus flat feet. Medial ankle pain must also be carefully investigated, and the presence of instability assessed with dynamic maneuvers (forced inversion, or dorsiflexion) of the foot. Sonography plays an important role in the investigation of disorders involving the posterior tibial tendon.

  3. Posterior vitreous detachment.

    PubMed

    Thimons, J J

    1992-01-01

    Posterior vitreous detachment is an expected consequence of aging, but it can also be the initiating cause of a retinal detachment. To understand the mechanism of posterior vitreous detachment and its sequelae, it is necessary to appreciate the anatomy of the vitreous, its development, and the pathogenesis of vitreous degeneration. This paper is a discussion of these considerations, the types of complications that may result from vitreous detachment, the proper examination of patients who present with the symptoms of vitreous detachment, and appropriate patient management.

  4. Posterior crossbites in children.

    PubMed

    Zhu, J F; Crevoisier, R; King, D L; Henry, R; Mills, C M

    1996-11-01

    Posterior crossbite, the most common malocclusion in young children, can be caused by a variety of skeletal, muscular, or dental factors. This condition produces insufficient maxillary arch width and is frequently associated with various oral sucking and postural habits. If left untreated, this problem can result in adverse skeletal growth changes. Various mechanical treatment modalities designed to expand the posterior maxillary arch width are available to correct this problem. The appropriate treatment method depends on the patient's age and level of cooperation as well as the determined etiology of the constriction.

  5. Posterior Fossa Tumors.

    PubMed

    Brandão, Lara A; Young Poussaint, Tina

    2017-02-01

    Pediatric brain tumors are the leading cause of death from solid tumors in childhood. The most common posterior fossa tumors in children are medulloblastoma, atypical teratoid/rhabdoid tumor, cerebellar pilocytic astrocytoma, ependymoma, and brainstem glioma. Location, and imaging findings on computed tomography (CT) and conventional MR (cMR) imaging may provide important clues to the most likely diagnosis. Moreover, information obtained from advanced MR imaging techniques increase diagnostic confidence and help distinguish between different histologic tumor types. Here we discuss the most common posterior fossa tumors in children, including typical imaging findings on CT, cMR imaging, and advanced MR imaging studies.

  6. Tibialis Posterior Tendon Entrapment Within Posterior Malleolar Fracture Fragment.

    PubMed

    Fantry, Amanda; Lareau, Craig; Vopat, Bryan; Blankenhorn, Brad

    2016-01-01

    Management of posterior malleolus fractures continues to be controversial, with respect to both need for fixation and fixation methods. Fixation methods include an open posterior approach to the ankle as well as percutaneous reduction and fixation with or without arthroscopy for visualization of the articular surface. Plain radiographs are unreliable in identifying fracture pattern and intraoperative reduction, making arthroscopy a valuable adjunct to posterior malleolus fracture management. In this article, we report a case of tibialis posterior tendon entrapment within a posterior malleolus fracture, as identified by arthroscopy and managed with open reduction. Tibialis posterior tendon entrapment within a posterior malleolus has not been previously reported. Ankle arthroscopy for posterior malleolus fractures provides an opportunity to identify soft-tissue or tendinous entrapment, articular surface reduction, and articular cartilage injuries unlikely to be identified with fluoroscopy alone and should be considered in reduction and fixation of posterior malleolus fractures.

  7. Posterior Knee Loose Bodies: Treated by Posterior Knee Arthroscopy

    PubMed Central

    Chai, Ho Lam; Lui, Tun Hing

    2017-01-01

    Introduction: The posterior portion of the knee joint, which includes the tibial attachment of the posterior cruciate ligament and the posterior horn of the menisci, has been called a “blind spot” because it is difficult to observe this area under arthroscopy through standard anterior portals. Posteromedial, posterolateral, and posterior transseptal portals have been developed for visualization and instrumentation of the posteromedial and posterolateral compartments of the knee joint. Case Report: A 57-year-old man presented of persistent left posterior knee pain for 1 year. Radiographs and magnetic resonance imaging showed posterior knee encapsulated loose bodies. The symptoms did not respond to physiotherapy and analgesics. The loose bodies were removed via posterior knee arthroscopy. The symptoms subsided afterward. Conclusion: Lateral portal of the knee allows establishment of the posterolateral portal under endoscopic visualization, and the loose bodies of the posterior compartment of the knee can be effectively removed via the posterior knee arthroscopy. PMID:28819604

  8. 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...

  9. Activation of toxoplasma retinochoroiditis during pregnancy and evaluation of ocular findings in newborns.

    PubMed

    Türkcü, Fatih Mehmet; Şahin, Alparslan; Yüksel, Harun; Çınar, Yasin; Cingü, Kürşat; Altındağ, Suat; Deveci, Özcan; Özkurt, Zeynep; Çaça, İhsan

    2017-06-01

    The purpose of this study was to evaluate patients with activation of toxoplasma retinochoroiditis during pregnancy and ocular findings in newborns. A total of 17 pregnant patients who were clinically and serologically diagnosed with ocular toxoplasmosis were retrospectively reviewed. After birth, ocular findings for all infants were recorded. The mean age of the patients was 29.08 ± 5.71 years. In all cases, activation was present in only one eye. In 13 cases, anterior uveitis was associated with posterior uveitis. Visual acuity in all cases prior to treatment was 0.3 ± 0.21 and increased to 0.55 ± 0.29 after treatment. The mean gestational age of the patients was 19.76 ± 8.71 weeks at the time of hospital admission. No case of toxoplasmic ocular involvement was identified in the infants on postnatal examination. In the case of toxoplasma retinochoroiditis during pregnancy, appropriate treatment and follow-up is very important to protect the newborns and to prevent impaired vision in mothers.

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

    USDA-ARS?s Scientific Manuscript database

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

  11. Posterior Circulation Ischemic Stroke.

    PubMed

    Go, Steven

    2015-01-01

    Approximately 20-25% of all acute strokes occur in the posterior circulation. These strokes can be rather difficult to diagnose because they present in such diverse ways, and can easily be mistaken for more benign entities. A fastidious history, physical exam, high clinical suspicion, and appropriate use of imaging are essential for the emergency physician to properly diagnose and treat these patients. Expert stroke neurologist consultation should be utilized liberally.

  12. Contribution of the Residual Body in the Spatial Organization of Toxoplasma gondii Tachyzoites within the Parasitophorous Vacuole

    PubMed Central

    Muñiz-Hernández, S.; González del Carmen, M.; Mondragón, M.; Mercier, C.; Cesbron, M. F.; Mondragón-González, S. L.; González, S.; Mondragón, R.

    2011-01-01

    Toxoplasma gondii proliferates and organizes within a parasitophorous vacuole in rosettes around a residual body and is surrounded by a membranous nanotubular network whose function remains unclear. Here, we characterized structure and function of the residual body in intracellular tachyzoites of the RH strain. Our data showed the residual body as a body limited by a membrane formed during proliferation of tachyzoites probably through the secretion of components and a pinching event of the membrane at the posterior end. It contributes in the intravacuolar parasite organization by the membrane connection between the tachyzoites posterior end and the residual body membrane to give place to the rosette conformation. Radial distribution of parasites in rosettes favors an efficient exteriorization. Absence of the network and presence of atypical residual bodies in a ΔGRA2-HXGPRT knock-out mutant affected the intravacuolar organization of tachyzoites and their exteriorization. PMID:22190852

  13. [Posterior cortical atrophy].

    PubMed

    Solyga, Volker Moræus; Western, Elin; Solheim, Hanne; Hassel, Bjørnar; Kerty, Emilia

    2015-06-02

    Posterior cortical atrophy is a neurodegenerative condition with atrophy of posterior parts of the cerebral cortex, including the visual cortex and parts of the parietal and temporal cortices. It presents early, in the 50s or 60s, with nonspecific visual disturbances that are often misinterpreted as ophthalmological, which can delay the diagnosis. The purpose of this article is to present current knowledge about symptoms, diagnostics and treatment of this condition. The review is based on a selection of relevant articles in PubMed and on the authors' own experience with the patient group. Posterior cortical atrophy causes gradually increasing impairment in reading, distance judgement, and the ability to perceive complex images. Examination of higher visual functions, neuropsychological testing, and neuroimaging contribute to diagnosis. In the early stages, patients do not have problems with memory or insight, but cognitive impairment and dementia can develop. It is unclear whether the condition is a variant of Alzheimer's disease, or whether it is a separate disease entity. There is no established treatment, but practical measures such as the aid of social care workers, telephones with large keypads, computers with voice recognition software and audiobooks can be useful. Currently available treatment has very limited effect on the disease itself. Nevertheless it is important to identify and diagnose the condition in its early stages in order to be able to offer patients practical assistance in their daily lives.

  14. Posterior Shoulder Instability.

    PubMed

    Brelin, Alaina; Dickens, Jonathan F

    2017-09-01

    Posterior shoulder instability is a relatively uncommon condition, occurring in ∼10% of those with shoulder instability. Because of the rarity of the condition and the lack of knowledge in treatment, it is often misdiagnosed or patients experience a delay in diagnosis. Posterior instability typically affects athletes participating in contact or overhead sports and is usually the result of repetitive microtrauma or blunt force with the shoulder in the provocative position of flexion, adduction, and internal rotation, leading to recurrent subluxation events. Acute traumatic posterior dislocations are rare injuries with an incidence rate of 1.1 per 100,000 person years. This rate is ∼20 times lower than that of anterior shoulder dislocations. Risk factors for recurrent instability are: (1) age below 40 at time of first instability; (2) dislocation during a seizure; (3) a large reverse Hill-Sachs lesion; and (4) glenoid retroversion. A firm understanding of the pathoanatomy, along with pertinent clinical and diagnostic modalities is required to accurately diagnosis and manage this condition.

  15. Persistent occiput posterior.

    PubMed

    Barth, William H

    2015-03-01

    Persistent occiput posterior (OP) is associated with increased rates of maternal and newborn morbidity. Its diagnosis by physical examination is challenging but is improved with bedside ultrasonography. Occiput posterior discovered in the active phase or early second stage of labor usually resolves spontaneously. When it does not, prophylactic manual rotation may decrease persistent OP and its associated complications. When delivery is indicated for arrest of descent in the setting of persistent OP, a pragmatic approach is suggested. Suspected fetal macrosomia, a biparietal diameter above the pelvic inlet or a maternal pelvis with android features should prompt cesarean delivery. Nonrotational operative vaginal delivery is appropriate when the maternal pelvis has a narrow anterior segment but ample room posteriorly, like with anthropoid features. When all other conditions are met and the fetal head arrests in an OP position in a patient with gynecoid pelvic features and ample room anteriorly, options include cesarean delivery, nonrotational operative vaginal delivery, and rotational procedures, either manual or with the use of rotational forceps. Recent literature suggests that maternal and fetal outcomes with rotational forceps are better than those reported in older series. Although not without significant challenges, a role remains for teaching and practicing selected rotational forceps operations in contemporary obstetrics.

  16. Detection Method of TOXOPLASMA GONDII Tachyzoites

    NASA Astrophysics Data System (ADS)

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

    2011-06-01

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

  17. Posterior interosseous neuropathy

    PubMed Central

    Kele, Henrich; Xia, Annie; Weiler, Markus; Schwarz, Daniel; Bendszus, Martin; Pham, Mirko

    2016-01-01

    Objective: To investigate the spatial pattern of lesion dispersion in posterior interosseous neuropathy syndrome (PINS) by high-resolution magnetic resonance neurography. Methods: This prospective study was approved by the local ethics committee and written informed consent was obtained from all patients. In 19 patients with PINS and 20 healthy controls, a standardized magnetic resonance neurography protocol at 3-tesla was performed with coverage of the upper arm and elbow (T2-weighted fat-saturated: echo time/repetition time 52/7,020 milliseconds, in-plane resolution 0.27 × 0.27 mm2). Lesion classification of the radial nerve trunk and its deep branch (which becomes the posterior interosseous nerve) was performed by visual rating and additional quantitative analysis of normalized T2 signal of radial nerve voxels. Results: Of 19 patients with PINS, only 3 (16%) had a focal neuropathy at the entry of the radial nerve deep branch into the supinator muscle at elbow/forearm level. The other 16 (84%) had proximal radial nerve lesions at the upper arm level with a predominant lesion focus 8.3 ± 4.6 cm proximal to the humeroradial joint. Most of these lesions (75%) followed a specific somatotopic pattern, involving only those fascicles that would form the posterior interosseous nerve more distally. Conclusions: PINS is not necessarily caused by focal compression at the supinator muscle but is instead frequently a consequence of partial fascicular lesions of the radial nerve trunk at the upper arm level. Neuroimaging should be considered as a complementary diagnostic method in PINS. PMID:27683851

  18. Toxoplasma gondii: Laboratory Maintenance and Growth.

    PubMed

    Khan, Asis; Grigg, Michael E

    2017-02-06

    Toxoplasma gondii is a highly successful apicomplexan protozoan capable of infecting any warm-blooded animal worldwide. In humans, Toxoplasma infections are life-long, with approximately one-third of the world's population chronically infected. Although normally controlled by the host immune system, T. gondii infection can lead to a variety of clinical outcomes in individuals with immature or suppressed immune systems. After penetrating the intestine, parasites rapidly disseminate throughout the body and stimulate production of the cytokines interleukin (IL)-12, IL-18, and interferon (IFN)-γ by immune cells. These cytokines play a key role in host resistance to T. gondii by promoting a strong Th1 response. Recent reports show that gut commensal bacteria can act as molecular adjuvants during T. gondii infection. Thus, T. gondii is an excellent model system to study host-pathogen interactions. This unit outlines the protocols for in vitro and in vivo maintenance and growth of T. gondii. © 2017 by John Wiley & Sons, Inc. Copyright © 2017 John Wiley & Sons, Inc.

  19. Symptomatic posterior mediastinal angioleiomyoma.

    PubMed

    I, Hoseok; Jeong, Yeon Joo; Choi, Kyung Un; Kim, Yeong-Dae

    2008-08-30

    We report a case of a symptomatic angioleiomyoma in the left posterior mediastinum. A 66-year-old woman presented with left back and flank pain for 6 months. Chest computed tomography (CT) and magnetic resonance imaging (MRI) revealed a well-circumscribed 4.3 cm round mass. The mass was initially diagnosed as nerve sheath tumor, because of her symptoms and its close location to the sympathetic trunk and intercostal nerve. It was uneventfully removed through video-assisted thoracoscopic surgery. The pathology revealed an angioleiomyoma.

  20. Posterior Urethral Strictures

    PubMed Central

    Gelman, Joel; Wisenbaugh, Eric S.

    2015-01-01

    Pelvic fracture urethral injuries are typically partial and more often complete disruptions of the most proximal bulbar and distal membranous urethra. Emergency management includes suprapubic tube placement. Subsequent primary realignment to place a urethral catheter remains a controversial topic, but what is not controversial is that when there is the development of a stricture (which is usually obliterative with a distraction defect) after suprapubic tube placement or urethral catheter removal, the standard of care is delayed urethral reconstruction with excision and primary anastomosis. This paper reviews the management of patients who suffer pelvic fracture urethral injuries and the techniques of preoperative urethral imaging and subsequent posterior urethroplasty. PMID:26691883

  1. Targeting tumors with nonreplicating Toxoplasma gondii uracil auxotroph vaccines

    PubMed Central

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

    2013-01-01

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

  2. Toxoplasma histone acetylation remodelers as novel drug targets

    PubMed Central

    Vanagas, Laura; Jeffers, Victoria; Bogado, Silvina S; Dalmasso, Maria C; Sullivan, William J; Angel, Sergio O

    2013-01-01

    Toxoplasma gondii is a leading cause of neurological birth defects and a serious opportunistic pathogen. The authors and others have found that Toxoplasma uses a unique nucleosome composition supporting a fine gene regulation together with other factors. Post-translational modifications in histones facilitate the establishment of a global chromatin environment and orchestrate DNA-related biological processes. Histone acetylation is one of the most prominent post-translational modifications influencing gene expression. Histone acetyltransferases and histone deacetylases have been intensively studied as potential drug targets. In particular, histone deacetylase inhibitors have activity against apicomplexan parasites, underscoring their potential as a new class of antiparasitic compounds. In this review, we summarize what is known about Toxoplasma histone acetyltransferases and histone deacetylases, and discuss the inhibitors studied to date. Finally, the authors discuss the distinct possibility that the unique nucleosome composition of Toxoplasma, which harbors a nonconserved H2Bv variant histone, might be targeted in novel therapeutics directed against this parasite. PMID:23199404

  3. Posterior Cortical Atrophy

    PubMed Central

    Crutch, Sebastian J; Lehmann, Manja; Schott, Jonathan M; Rabinovici, Gil D; Rossor, Martin N; Fox, Nick C

    2013-01-01

    Posterior cortical atrophy (PCA) is a neurodegenerative syndrome that is characterized by a progressive decline in visuospatial, visuoperceptual, literacy and praxic skills. The progressive neurodegeneration affecting parietal, occipital and occipito-temporal cortices which underlies PCA is attributable to Alzheimer's disease (AD) in the majority of patients. However, alternative underlying aetiologies including Dementia with Lewy Bodies (DLB), corticobasal degeneration (CBD) and prion disease have also been identified, and not all PCA patients have atrophy on clinical imaging. This heterogeneity has led to diagnostic and terminological inconsistencies, caused difficulty comparing studies from different centres, and limited the generalizability of clinical trials and investigations of factors driving phenotypic variability. Significant challenges remain in identifying the factors associated with both the selective vulnerability of posterior cortical regions and the young age of onset seen in PCA. Greater awareness of the syndrome and agreement over the correspondence between syndrome-and disease-level classifications are required in order to improve diagnostic accuracy, research study design and clinical management. PMID:22265212

  4. Posterior Fossa Meningioma

    PubMed Central

    Saleh, Essam A.; Taibah, Abdel Kader; Achilli, Vittorio; Aristegui, Miguel; Mazzoni, Antonio; Sanna, Mario

    1994-01-01

    Posterior fossa meningioma is the second most common tumor in the cerebellopontine angle. It has a higher rate of postoperative morbidity and mortality compared to acoustic neuroma. Forty posterior fossa meningioma patients managed in our centers were reviewed. Thirty-nine patients were managed surgically with 42 surgical procedures. The approaches used were the translabyrinthine approach in 18 patients (43%), the modified transcochlear in 11 cases (26%), the petro-occipital transsigmoid in 5 cases (12%), the suboccipital in 4 cases (10%), the petro-occipital trassigmoid transcervical in 2 cases (5%), the petro-occipital transsigmoid transtentorial in 1 case (2%), and a subtemporal transtentorial for another case (2%). Facial nerve anatomical integrity was preserved in 87% of procedures but was interrupted in 5 cases, with 4 of the latter subsequently repaired. Total tumor removal was accomplished in 38 cases. A second-stage total tumor removal is planned for the remaining case. There was only one case of perioperative death and no cases of radiological recurrence so far. ImagesFigure 1Figure 2Figure 3Figure 4p206-bFigure 5p207-bFigure 5 PMID:17171173

  5. Toxoplasma gondii decreases the reproductive fitness in mice.

    PubMed

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

    2014-01-01

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

  6. Toxoplasma gondii infection in schizophrenia and associated clinical features.

    PubMed

    Esshili, Awatef; Thabet, Sihem; Jemli, Achraf; Trifa, Fatma; Mechri, Anouar; Zaafrane, Ferid; Gaha, Lotfi; Juckel, Georg; Babba, Hamouda; Bel Hadj Jrad, Besma

    2016-11-30

    The belief that latent toxoplasmosis is asymptomatic has been questioned, in particular due to the repeated highlighted link between the Toxoplasma gondii infection and an increased incidence of schizophrenia. However, to understand this relationship, the effect of infection with Toxoplasma gondii on the severity of schizophrenia has been poorly studied. Our work focused on comparing the prevalence of Toxoplasma infection between schizophrenic patients and healthy controls, as well as comparing the clinical features and the demographic characteristics between Toxoplasma-seronegative and Toxoplasma-seropositive patients with schizophrenia. The rate of IgG antibody in the schizophrenia patients was 74.8% compared 53.8% in controls. Patients with schizophrenia had a significantly higher mean of serum IgG antibodies to T. gondii compared to controls. The seropositive male patients had a higher age of disease onset, a higher BPRS score, a greater negative PANSS score and a lower GAF score than the seronegative male patients. These results suggest a higher severity of clinical symptoms in the male patients with schizophrenia. This study provides further evidence to the hypothesis that exposure to Toxoplasma may be a risk factor for schizophrenia. Moreover, toxoplasmosis in men with schizophrenia may lead to more severe negative and cognitive symptoms and a less favorable course of schizophrenia. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

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

    NASA Astrophysics Data System (ADS)

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

    2009-07-01

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

  8. Opposing Transcriptional Mechanisms Regulate Toxoplasma Development

    PubMed Central

    Hong, Dong-Pyo; Radke, Joshua B.

    2017-01-01

    ABSTRACT The Toxoplasma biology that underlies human chronic infection is developmental conversion of the acute tachyzoite stage into the latent bradyzoite stage. We investigated the roles of two alkaline-stress-induced ApiAP2 transcription factors, AP2IV-3 and AP2IX-9, in bradyzoite development. These factors were expressed in two overlapping waves during bradyzoite development, with AP2IX-9 increasing expression earlier than AP2IV-3, which peaked as AP2IX-9 expression was declining. Disruption of the AP2IX-9 gene enhanced, while deletion of AP2IV-3 gene decreased, tissue cyst formation, demonstrating that these factors have opposite functions in bradyzoite development. Conversely, conditional overexpression of FKBP-modified AP2IX-9 or AP2IV-3 with the small molecule Shield 1 had a reciprocal effect on tissue cyst formation, confirming the conclusions of the knockout experiments. The AP2IX-9 repressor and AP2IV-3 activator tissue cyst phenotypes were borne out in gene expression studies that determined that many of the same bradyzoite genes were regulated in an opposite manner by these transcription factors. A common gene target was the canonical bradyzoite marker BAG1, and mechanistic experiments determined that, like AP2IX-9, AP2IV-3 regulates a BAG1 promoter-luciferase reporter and specifically binds the BAG1 promoter in parasite chromatin. Altogether, these results suggest that the AP2IX-9 transcriptional repressor and the AP2IV-3 transcriptional activator likely compete to control bradyzoite gene expression, which may permit Toxoplasma to better adapt to different tissue environments and select a suitable host cell for long-term survival of the dormant tissue cyst. IMPORTANCE Toxoplasma infections are lifelong because of the development of the bradyzoite tissue cyst, which is effectively invisible to the immune system. Despite the important clinical consequences of this developmental pathway, the molecular basis of the switch mechanisms that control tissue

  9. Novel posterior fixation keratoprosthesis

    NASA Astrophysics Data System (ADS)

    Lacombe, Emmanuel

    1992-08-01

    The keratoprosthesis is the last solution for corneally blind patients that cannot benefit from corneal transplants. Keratoprostheses that have been designed to be affixed anteriorly usually necessitate multi-step surgical procedures and are continuously subjected to the extrusion forces generated by the positive intraocular pressure; therefore, clinical results in patients prove inconsistent. We proposed a novel keratoprosthesis concept that utilizes posterior corneal fixation which `a priori' minimizes the risk of aqueous leakage and expulsion. This prosthesis is implanted in a single procedure thereby reducing the number of surgical complications normally associated with anterior fixation devices. In addition, its novel design makes this keratoprosthesis implantable in phakic eyes. With an average follow-up of 13 months (range 3 to 25 months), our results on 21 cases are encouraging. Half of the keratoprostheses were implanted in severe burn cases, with the remainder in cases of pseudo- pemphigus. Good visual results and cosmetic appearance were obtained in 14 of 21 eyes.

  10. [Posterior reversible encephalopathy syndrome].

    PubMed

    Petrović, Branko; Kostić, Vladimir; Sternić, Nadezda; Kolar, Jovo; Tasić, Nebojsa

    2003-01-01

    Reversible Posterior Leukoencephalopathy Syndrome was introduced into clinical practice in 1996 in order to describe unique syndrome, clinically expressed during hypertensive and uremic encephalopathy, eclampsia and during immunosuppressive therapy [1]. First clinical investigations showed that leucoencephalopathy is major characteristic of the syndrome, but further investigations showed no significant destruction in white cerebral tissue [2, 3, 4]. In majority of cases changes are localise in posterior irrigation area of the brain and in the most severe cases anterior region is also involved. Taking into consideration all above mentioned facts, the suggested term was Posterior Reversible Encephalopathy Syndrome (PRES) for the syndrome clinically expressed by neurological manifestations derived from cortical and subcortical changes localised in posterior regions of cerebral hemispheres, cerebral trunk and cerebellum [5]. Patient, aged 53 years, was re-hospitalized in Cardiovascular Institute "Dediwe" two months after successful aorto-coronary bypass performed in June 2001 due to the chest bone infection. During the treatment of the infection (according to the antibiogram) in September 2001, patient in evening hours developed headache and blurred vision. The recorded blood pressure was 210/120 mmHg so antihypertensive treatment was applied (Nifedipin and Furosemid). After this therapy there was no improvement and intensive headache with fatigue and loss of vision developed. Neurological examination revealed cortical blindness and left hemiparesis. Manitol (20%, 60 ccm every 3 hours) and i.v. Nytroglicerin (high blood pressure). Brain CT revealed oedema of parieto-occipital regions of both hemispheres, more emphasized on the right. (Figure 1a, b, c). There was no sign of focal ischemia even in deeper sections (Figure 1d, e, f). Following three days enormous high blood pressure values were registered. On the fourth day the significant clinical improvement occurred

  11. Posterior pole tumor update.

    PubMed

    Ou, Judy I; Wheeler, Sharon M; O'Brien, Joan M

    2002-12-01

    This chapter focuses on the diagnosis and management of choroidal melanoma in light of recent findings from the COMS. Retinoblastoma is emphasized to describe recent trends in primary treatment away from EBRT and toward chemoreduction with local therapy. In addition, vascular and glial tumors of the retina and tumors of the retinal pigment epithelium are described because of the association between these lesions and systemic disease. Recent advances in treatment and genetic testing for these diseases are discussed. Finally, ocular metastasis, intraocular lymphoid tumors, and intraocular leukemia are included because of their importance in determining systemic treatment and prognosis. The chapter gives an overview of important posterior pole tumors and highlights recent developments in the management of each intraocular disease process.

  12. 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

  13. Toxoplasma gondii: history and diagnostic test development.

    PubMed

    Wyrosdick, Heidi M; Schaefer, John J

    2015-12-01

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

  14. 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

  15. Cytoskeleton assembly in Toxoplasma gondii cell division

    PubMed Central

    Anderson-White, Brooke; Beck, Josh R.; Chen, Chun-Ti; Meissner, Markus; Bradley, Peter J.; Gubbels, Marc-Jan

    2014-01-01

    Cell division across members of the protozoan parasite phylum Apicomplexa displays a surprising diversity between different species as well as between different life stages of the same parasite. In most cases, infection of a host cell by a single parasite results in the formation of a polyploid cell from which individual daughters bud in a process dependent on a final round of mitosis. Unlike other apicomplexans, Toxoplasma gondii divides by a binary process consisting of internal budding that results in only two daughter cells per round of division. Since T. gondii is experimentally accessible and displays the simplest division mode, it has manifested itself as a model for apicomplexan daughter formation. Here we review newly emerging insights in the prominent role that assembly of the cortical cytoskeletal scaffold plays in the process of daughter parasite formation. PMID:22878103

  16. 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.

  17. Reduction of the abortion rate due to Toxoplasma in 3 goat herds following administration of sulfadimidine

    PubMed Central

    Giadinis, Nektarios D.; Lafi, Shawkat Q.; Ioannidou, Evi; Papadopoulos, Elias; Terpsidis, Konstantinos; Karanikolas, George; Petridou, Evanthia J.; Brozos, Christos; Karatzias, Harilaos

    2013-01-01

    The efficacy of sulfadimidine (4 doses of 33 mg/kg body weight, IM, q48h) against Toxoplasma abortion was assessed in 3 dairy goat herds suffering from Toxoplasma abortions during the 4th month of gestation. This protocol was very effective for the control of Toxoplasma abortions (P < 0.01). PMID:24179245

  18. Clinical spectrum, diagnostic criteria, and polymerase chain reaction of aqueous humor in viral and toxoplasma detection in Fuchs’ uveitis syndrome

    PubMed Central

    Sabhapandit, Swapnali; Murthy, Somasheila I; Balne, Praveen K; Sangwan, Virender Singh; Sumanth, V; Reddy, Ashok K

    2016-01-01

    Aim: The aim of this study is to describe the clinical features and diagnostic criteria of Fuchs’ uveitis (FU) and to determine whether it has an association with virus and toxoplasma in the aqueous humor during cataract surgery. Setting and Design: This is a prospective, case–control study. Materials and Methods: Patients with FU (n = 25), anterior uveitis (n = 15), and no uveitis (normal) (n = 50) were included based on predefined inclusion and exclusion criteria for all three groups. Polymerase chain reaction (PCR) of aqueous humor and serum for rubella, herpes simplex virus (HSV), cytomegalovirus (CMV), varicella-zoster virus (VZV), and toxoplasma was done using conventional uniplex PCR. Statistical Analysis: It was done using SPSS software using Chi-square test for categorical variables, and P < 0.05 was considered statistically significant. Results: Ninety patients were enrolled in the study in three groups, comparable for age, gender, and laterality of ocular involvement. All patients had diffuse keratic precipitates in FU group (P = 0001) with none having posterior synechiae (P = 0.046) which was statistically significant when compared to anterior uveitis patients. Iris nodules were noted in one case in both groups. Serum and aqueous PCR was negative for detection of VZV, CMV, toxoplasma, and rubella in all groups. PCR for HSV was positive in one patient in “normal” group but was not statistically significant. Conclusion: Our study shows that diagnosis of FU is mainly clinical. There appears to be no role of aqueous humor testing for viruses by PCR to aid in etiological diagnosis. PMID:27688274

  19. Posterior sampling with improved efficiency

    SciTech Connect

    Hanson, K.M.; Cunningham, G.S.

    1998-12-01

    The Markov Chain Monte Carlo (MCMC) technique provides a means to generate a random sequence of model realizations that sample the posterior probability distribution of a Bayesian analysis. That sequence may be used to make inferences about the model uncertainties that derive from measurement uncertainties. This paper presents an approach to improving the efficiency of the Metropolis approach to MCMC by incorporating an approximation to the covariance matrix of the posterior distribution. The covariance matrix is approximated using the update formula from the BFGS quasi-Newton optimization algorithm. Examples are given for uncorrelated and correlated multidimensional Gaussian posterior distributions.

  20. Use and abuse of dendritic cells by Toxoplasma gondii

    PubMed Central

    Sanecka, Anna; Frickel, Eva-Maria

    2012-01-01

    The ubiquitous apicomplexan parasite Toxoplasma gondii stimulates its host’s immune response to achieve quiescent chronic infection. Central to this goal are host dendritic cells. The parasite exploits dendritic cells to disseminate through the body, produce pro-inflammatory cytokines, present its antigens to the immune system and yet at the same time subvert their signaling pathways in order to evade detection. This carefully struck balance by Toxoplasma makes it the most successful parasite on this planet. Recent progress has highlighted specific parasite and host molecules that mediate some of these processes particularly in dendritic cells and in other cells of the innate immune system. Critically, there are several important factors that need to be taken into consideration when concluding how the dendritic cells and the immune system deal with a Toxoplasma infection, including the route of administration, parasite strain and host genotype. PMID:23221473

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

    PubMed Central

    Ryning, Frank W.; Mills, John

    1979-01-01

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

  2. 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.

  3. Synthesis and Evaluation of Oryzalin Analogs against Toxoplasma gondii

    PubMed Central

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

    2010-01-01

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

  4. Detection of Toxoplasma gondii Oocysts in Drinking Water

    PubMed Central

    Isaac-Renton, Judith; Bowie, William R.; King, Arlene; Irwin, G. Stewart; Ong, Corinne S.; Fung, C. P.; Shokeir, M. Omar; Dubey, J. P.

    1998-01-01

    The world’s largest outbreak of waterborne toxoplasmosis occurred in a municipality in the western Canadian province of British Columbia. When drinking water emerged as a possible source of infection during the outbreak investigation, a laboratory method was needed to attempt detection of the parasite, Toxoplasma gondii. The method developed was based on the current U.S. Environmental Protection Agency method for detection of Cryptosporidium oocysts. Collection of large-volume drinking water samples and cartridge filter processing were unchanged, although identification of Toxoplasma oocysts in the filter retentate was carried out by using a previously described rodent model. Validation of the method developed was tested by using oocysts from a well-characterized Toxoplasma strain. PMID:9603850

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

    PubMed

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

    2014-12-05

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

  6. Hypernatremia in a Cat with Toxoplasma-Induced Panencephalitis.

    PubMed

    Weingart, Christiane; Gruber, Achim D; Brunnberg, Mathias; Kohn, Barbara

    2016-01-01

    A 12 yr old female neutered Carthusian crossbreed cat was presented due to progressive neurological signs. Clinical signs included dehydration, stupor, and anisocoria. Laboratory examination revealed severe hypernatremia, azotemia, hyperglobulinemia, and an erythrocytosis. Clinical signs and hypernatremia suggested an intracranial process. Imaging studies revealed a loss of structure in the cerebrum, hypothalamus, and pituitary gland. Due to a poor prognosis, the cat was euthanatized. Histopathological examination revealed a subacute granulomatous and necrotizing panencephalitis with Toxoplasma-typical protozoa. The Toxoplasma-induced dysfunction of the hypothalamus and pituitary gland led to diabetes insipidus, which was, in combination with insufficient water intake, the most likely cause for the hypernatremia.

  7. Fetal Toxoplasma infection after oocyst inoculation of pregnant rats.

    PubMed

    Freyre, A; Falcón, J; Mendez, J; González, M; Venzal, J M; Morgades, D

    2003-03-01

    Six groups totalling 53 Wistar rats were fed 10(4)oocysts from one of six different Toxoplasma strains at 15 days of pregnancy. The overall transplacental transmission rate was 51%. This varied between 10% and 80%, dependent on the strain used. The strains of Toxoplasma which are more pathogenic for mice were transmitted transplacentally more frequently than the strains of intermediate or low pathogenicity. There were no statistically significant differences in the rate of congenital transmission of Toxoplasmain rats fed oocysts (present work) or cysts (previous work).

  8. Mechanics of the Toxoplasma gondii oocyst wall

    PubMed Central

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

    2013-01-01

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

  9. Toxoplasma gondii Chitinase Induces Macrophage Activation

    PubMed Central

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

    2015-01-01

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

  10. Structures of the Toxoplasma gliding motility adhesin

    PubMed Central

    Song, Gaojie; Springer, Timothy A.

    2014-01-01

    Micronemal protein 2 (MIC2) is the key adhesin that supports gliding motility and host cell invasion by Toxoplasma gondii. With a von Willebrand factor A (VWA) domain and six thrombospondin repeat domains (TSR1–6) in its ectodomain, MIC2 connects to the parasite actomyosin system through its cytoplasmic tail. MIC2-associated protein (M2AP) binds noncovalently to the MIC2 ectodomain. MIC2 and M2AP are stored in micronemes as proforms. We find that the MIC2–M2AP ectodomain complex is a highly elongated 1:1 monomer with M2AP bound to the TSR6 domain. Crystal structures of N-terminal fragments containing the VWA and TSR1 domains for proMIC2 and MIC2 reveal a closed conformation of the VWA domain and how it associates with the TSR1 domain. A long, proline-rich, disulfide-bonded pigtail loop in TSR1 overlaps the VWA domain. Mannose α-C-linked to Trp-276 in TSR1 has an unusual 1C4 chair conformation. The MIC2 VWA domain includes a mobile α5-helix and a 22-residue disordered region containing two disulfide bonds in place of an α6-helix. A hydrophobic residue in the prodomain binds to a pocket adjacent to the α7-helix that pistons in opening of the VWA domain to a putative high-affinity state. PMID:24639528

  11. Recent Advances in Toxoplasma gondii Immunotherapeutics

    PubMed Central

    Othman, Rofina Yasmin

    2014-01-01

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

  12. Characterization of aspartyl aminopeptidase from Toxoplasma gondii

    PubMed Central

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

    2016-01-01

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

  13. 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.

  14. [Treatment of recurrent posterior epistaxis].

    PubMed

    Bro, Søren Pauli; Bille, Jesper; Petersen, Kristian Bruun

    2017-08-21

    30% of the patients presenting with epistaxis at emergency wards and otorhinolaryngeal specialist departments have posterior bleeding. Traditional treatment with packing often leads to initial treatment failure, and many patients experience recurrent bleeding within the following month. Recurrent posterior epistaxis should be treated with local electrocautery or endoscopic ligation of the sphenopalatine artery to reduce patient discomfort, hospital stay, risk of treatment failure and recurrence.

  15. Syphilitic posterior placoid chorioretinitis as initial presentation of early neurosyphilis.

    PubMed

    Molina-Sócola, F E; López-Herrero, F; Medina-Tapia, A; Rueda-Rueda, T; Contreras-Díaz, M; Sánchez-Vicente, J L

    2017-10-01

    A 36 year-old male with a recent HIV diagnosis, presented with loss of vision of his left eye. Ophthalmoscopy revealed a unilateral yellowish placoid lesion in the macula. After fluorescein angiography, optical coherence tomography, optical coherence tomography angiography, syphilis serology, and cerebrospinal fluid results, he was diagnosed with neurosyphilis and syphilitic posterior placoid chorioretinitis. Acute syphilitic posterior placoid chorioretinitis is a rare ocular manifestation of syphilis. All patients with characteristic clinical and angiographic findings of acute syphilitic posterior placoid chorioretinitis should be tested for a neurosyphilis and human immunodeficiency virus co-infection. Early treatment with intravenous penicillin is usually effective with good visual results. Copyright © 2016 Sociedad Española de Oftalmología. Publicado por Elsevier España, S.L.U. All rights reserved.

  16. 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.

  17. [Seroprevalance Differences of Toxoplasma Between Syrian Refugees Pregnants and Indigenous Turkish Pregnants in Kahramanmaraş].

    PubMed

    Bakacak, Murat; Serin, Salih; Aral, Murat; Ercan, Önder; Köstü, Bülent; Kireçci, Ahmet; Bostancı, Mehmet Sühha; Bakacak, Zeyneb

    2015-06-01

    In this study, we aimed to compare the Syrian refugees and resident Turkish pregnant population in terms of Toxoplasma seroprevalence. Data acquired from Kahramanmaraş Necip Fazıl City Hospital Department of Obstetrics and Gynecology between 2012 and 2013 were analyzed retrospectively. Results of 7201 Toxoplasma IgM tests and 4113 Toxoplasma IgG tests were evaluated. For 2012 and 2013 Toxoplasma IgM seropositivity was found in Syrian refugees 4.76% and 4.84% respectively in our study. In the same population Toxoplasma IgG seropositivity rates were 80% and 62.6%, respectively. Toxoplasma IgM seropositivity rates for the native peoples in Turkey in 2012 and 2013 was 1.96% and 2.34%, while in the same population Toxoplasma IgG seropositivity was detected 49.7% and 45.7% respectively. Toxoplasma IgM seropositivity was statistically higher in Syrian refugees for each year (p <0.001 and 0.019, respectively). Toxoplasma IgG seropositivity of Syrian refugees was statistically higher (p <0.001 and <0.001 respectively). Since it was found in our study that toxoplasma seropositivity rates of Syrian refugees living in the region of Kahramanmaraş were statistically higher than the rates of local inhabitants, we consider that this condition should be taken into account in the follow-ups of Syrian pregnant refugees outnumbering in Kahramanmaraş and its vicinity.

  18. 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

  19. Combined posterior Bankart lesion and posterior humeral avulsion of the glenohumeral ligaments associated with recurrent posterior shoulder instability.

    PubMed

    Hill, J David; Lovejoy, John F; Kelly, Robert A

    2007-03-01

    Recurrent posterior glenohumeral instability is uncommon and is often misdiagnosed. Damage to the posterior capsule, posteroinferior glenohumeral ligament, and posterior labrum have all been implicated as sources of traumatic posterior instability. We describe a case of traumatic recurrent posterior instability resulting from a posterior Bankart lesion accompanied by posterior humeral avulsion of the glenohumeral ligaments. The Bankart lesion was repaired using a single arthroscopic suture anchor at the glenoid articular margin. The posterior humeral avulsion of the glenohumeral ligaments was addressed with 3 suture anchors placed at the capsular origin at the posterior humeral head. Using these anchors, the posterior capsule was advanced laterally and superiorly for a secure repair. Arthroscopic anatomic reconstruction of both lesions resulted in an excellent clinical outcome.

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

    USDA-ARS?s Scientific Manuscript database

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

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

    PubMed

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

    2017-02-01

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

  2. 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...

  3. 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...

  4. 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...

  5. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2008-12-01

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

  7. Genetic diversity among sea otter isolates of Toxoplasma gondii

    USDA-ARS?s Scientific Manuscript database

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

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

    USDA-ARS?s Scientific Manuscript database

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

  9. 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...

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

    USDA-ARS?s Scientific Manuscript database

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

  11. 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...

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

    USDA-ARS?s Scientific Manuscript database

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

  13. 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...

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

    USDA-ARS?s Scientific Manuscript database

    Twenty-three striped skunks (Mephitis mephitis) without demonstrable antibodies in 1:25 serum dilution in the modified agglutination test (MAT) were fed sporulated Toxoplasma gondii oocysts (9 skunks) or tissue cysts (10 skunks), and 4 skunks (controls) were not given T. gondii. Skunks were bled be...

  15. SEROPREVALENCE OF TOXOPLASMA GONDII ANTIBODIES IN CATS FROM PENNSLYVANIA

    USDA-ARS?s Scientific Manuscript database

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

  16. Toxoplasma gondii: The changing paradigm of congenital toxoplasmosis

    USDA-ARS?s Scientific Manuscript database

    Researchers have learned much concerning the population biology of Toxoplasma gondii over the past two decades. It is now apparent that many atypical genotypes exist besides the typical 3 genotypes (type I, type II & type III) first described from samples from Europe and the United States. These gen...

  17. Toxoplasma Co-opts Host Cells It Does Not Invade

    PubMed Central

    Koshy, Anita A.; Dietrich, Hans K.; Christian, David A.; Melehani, Jason H.; Shastri, Anjali J.; Hunter, Christopher A.; Boothroyd, John C.

    2012-01-01

    Like many intracellular microbes, the protozoan parasite Toxoplasma gondii injects effector proteins into cells it invades. One group of these effector proteins is injected from specialized organelles called the rhoptries, which have previously been described to discharge their contents only during successful invasion of a host cell. In this report, using several reporter systems, we show that in vitro the parasite injects rhoptry proteins into cells it does not productively invade and that the rhoptry effector proteins can manipulate the uninfected cell in a similar manner to infected cells. In addition, as one of the reporter systems uses a rhoptry:Cre recombinase fusion protein, we show that in Cre-reporter mice infected with an encysting Toxoplasma-Cre strain, uninfected-injected cells, which could be derived from aborted invasion or cell-intrinsic killing after invasion, are actually more common than infected-injected cells, especially in the mouse brain, where Toxoplasma encysts and persists. This phenomenon has important implications for how Toxoplasma globally affects its host and opens a new avenue for how other intracellular microbes may similarly manipulate the host environment at large. PMID:22910631

  18. 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...

  19. 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...

  20. 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...

  1. 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...

  2. 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...

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

    USDA-ARS?s Scientific Manuscript database

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

  4. 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.

  5. 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

  6. Posterior Glottic Insufficiency in Children.

    PubMed

    Padia, Reema; Smith, Marshall E

    2017-04-01

    Dysphonia secondary to posterior glottic insufficiency (PGI) can be difficult to identify and correct. Inadequate arytenoid approximation from medial arytenoid erosion results in a breathy, soft voice. The anatomical location of the gap is difficult to correct by vocal fold injection laryngoplasty. This study reviews the presentation, evaluation, and treatment for pediatric patients who were identified with PGI. An Institutional Review Board-approved chart review was performed on all patients who were diagnosed with PGI at our institution from 2013 to 2015. We studied the presentation, workup, and treatment for these patients, including laryngoscopy, parent or patient-based voice impairment ratings, and response to treatment. Seven patients were identified. Erosion of the medial arytenoid was identified on microlaryngoscopy for all of these patients. The patients had suboptimal improvement from injection laryngoplasty. Three patients underwent surgical correction with an endoscopic posterior cricoid reduction laryngoplasty (EPCRL) with significant improvement in voice, assessed by perceptual, laryngoscopic, and patient-based measures. The key diagnostic procedures to identify posterior glottic insufficiency include laryngoscopic findings of a posterior glottal gap, microlaryngoscopy with close inspection of the posterior glottis and medial arytenoids, and suboptimal response to injection laryngoplasty. The EPCRL is an effective procedure to treat dysphonia from PGI.

  7. Toxoplasma gondii infection and schizophrenia: a case control study in a low Toxoplasma seroprevalence Mexican population.

    PubMed

    Alvarado-Esquivel, Cosme; Urbina-Álvarez, Jesús David; Estrada-Martínez, Sergio; Torres-Castorena, Alejandro; Molotla-de-León, Gabriel; Liesenfeld, Oliver; Dubey, Jitender P

    2011-06-01

    There are conflicting reports concerning the association of Toxoplasma gondii infection and schizophrenia in humans. Therefore, we determined such association in a Mexican population of Mestizo ethnicity. Through a case-control study design, 50 schizophrenic patients and 150 control subjects matched by gender, age, residence place, and ethnicity were examined with enzyme-linked immunoassays for the presence and levels of T. gondii IgG antibodies and for the presence of T. gondii IgM antibodies. Schizophrenic patients attended a public psychiatric hospital in Durango City, Mexico, and the control group consisted of individuals of the general population of the same city. Socio-demographic, clinical and behavioral characteristics from the study subjects were also obtained. Both the seroprevalence and the level of T.gondii IgG antibodies were higher in schizophrenic patients (10/50; 20%) than in control subjects (8/150; 5.3%) (OR=4.44; 95% CI: 1.49-13.37; P=0.003). The IgG T. gondii levels higher than 150 IU/ml were more frequently observed in patients than in controls (10% versus 2%, respectively; P=0.02). One (50%) of the two patients with recently diagnosed schizophrenia and none of the controls had T. gondii IgM antibodies (P=0.01). T. gondii seropositivity was significantly higher in patients with a history of cleaning cat excrement (P=0.005), and suffering from simple schizophrenia (ICD-10 classification: F20.6) (P=0.03) than patients without these characteristics. Toxoplasma seroprevalence was also significantly higher in patients with simple schizophrenia (F20.6) than in those with paranoid schizophrenia (F20.0) (P=0.02). This study provides elements to clarify the controversial information on the association of T. gondii infection and schizophrenia. Published by Elsevier Ireland Ltd.

  8. Rethinking "posterior" tongue-tie.

    PubMed

    Douglas, Pamela Sylvia

    2013-12-01

    Currently, many clinicians who help with breastfeeding problems are diagnosing "posterior" tongue-tie in infants and performing or referring for frenotomy. In this "Speaking Out" article, I argue that the diagnosis of "posterior" tongue-tie has successfully raised awareness of the importance of impaired tongue function in breastfeeding difficulty. However, the diagnosis of "posterior" tongue-tie also applies a reductionist, medicalized theoretical frame to the complex problem of impaired tongue function, risking unintended outcomes. Impaired tongue function arises out of multiple interacting and co-evolving factors, including the interplay between social behaviors concerning breastfeeding and mother-infant biology. Consideration of theoretical frames is vital if we are to build an evidence base through efficient use of the scarce resources available for clinical breastfeeding research and minimize unintended outcomes.

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

    PubMed

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

    2010-10-01

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

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

    DTIC Science & Technology

    2008-08-01

    1-0574 TITLE: The Dialogue of Metastasis-Uncovering Juxtacrine Genetic Cascades with a Toxoplasma Gondii Enzyme PRINCIPAL...a Toxoplasma Gondii Enzyme 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Richard A. Steinman, M.D., Ph.D. 5d. PROJECT NUMBER...with the toxoplasma gondii enzyme uracil phosphoribosyl transferase (UPRT) constructed as a fusion protein with a C-terminal fluorescent tag

  11. TOXOPLASMA AND VIRAL ANTIBODIES AMONG HIV PATIENTS AND INMATES IN CENTRAL JAVA, INDONESIA.

    PubMed

    Sari, Yulia; Haryati, Sri; Raharjo, Irvan; Prasetyo, Afiono Agung

    2015-11-01

    In Indonesia, Toxoplasma and its associations with blood-borne viruses have been poorly studied. In order to study the association between anti-Toxoplasma antibodies and blood-borne viral antibodies, blood samples from 497 participants (375 inmates from four prisons in Central Java, Indonesia and 122 HIV patients at a Voluntary Counseling and Testing Clinic in Surakarta, Indonesia) were tested for serological markers of Toxoplasma, human immunodeficiency virus (HIV), hepatitis B virus (HBV), hepatitis C virus (HCV), hepatitis D virus (HDV) and human T-lymphotropic virus types I and II (HTLV-1/2). Anti-Toxoplasma IgG and IgM positivity rates were 41.6% and 3.6%, respectively. One point two percent of participants was positive for both anti-Toxoplasma IgG and IgM antibodies. Sixteen point five percent, 11.3%, 2.6% and 2.8% of participants were positive for anti- Toxoplasma IgG combined with anti-HCV antibodies, anti-Toxoplasma IgG combined with anti-HIV antibodies, anti-Toxoplasma IgM combined with anti-HIV antibodes and anti-Toxoplasma IgG combined with both anti-HIV and anti-HCV antibodies, respectively. Anti-Toxoplasma IgM seropositivity was associated with anti-HIV (aOR = 4.3; 95% CI: 1.112-16.204, p = 0.034). Anti-Toxoplasma IgG antibodies were associated with anti-HCV (aOR = 2.8; 95% CI: 1.749-4.538, p < 0.001) and history of injection drug use (aOR = 3.1; 95% CI: 1.905-5.093, p < 0.001). In conclusion, we recommend patients with HIV, HCV infection and injection drug users should be screened for Toxoplasma infection in Indonesia.

  12. Identification of the Moving Junction Complex of Toxoplasma gondii: A Collaboration between Distinct Secretory Organelles

    PubMed Central

    2005-01-01

    Apicomplexan parasites, including Toxoplasma gondii and Plasmodium sp., are obligate intracellular protozoa. They enter into a host cell by attaching to and then creating an invagination in the host cell plasma membrane. Contact between parasite and host plasma membranes occurs in the form of a ring-shaped moving junction that begins at the anterior end of the parasite and then migrates posteriorly. The resulting invagination of host plasma membrane creates a parasitophorous vacuole that completely envelops the now intracellular parasite. At the start of this process, apical membrane antigen 1 (AMA1) is released onto the parasite surface from specialized secretory organelles called micronemes. The T. gondii version of this protein, TgAMA1, has been shown to be essential for invasion but its exact role has not previously been determined. We identify here a trio of proteins that associate with TgAMA1, at least one of which associates with TgAMA1 at the moving junction. Surprisingly, these new proteins derive not from micronemes, but from the anterior secretory organelles known as rhoptries and specifically, for at least two, from the neck portion of these club-shaped structures. Homologues for these AMA1-associated proteins are found throughout the Apicomplexa strongly suggesting that this moving junction apparatus is a conserved feature of this important class of parasites. Differences between the contributing proteins in different species may, in part, be the result of selective pressure from the different niches occupied by these parasites. PMID:16244709

  13. Toxoplasma gondii in Individuals With Schizophrenia: Association With Clinical and Demographic Factors and With Mortality

    PubMed Central

    Dickerson, Faith; Boronow, John; Stallings, Cassie; Origoni, Andrea; Yolken, Robert

    2007-01-01

    Background: Increased rates of exposure to Toxoplasma gondii have been found in individuals with schizophrenia as compared with control groups, but the correlates of Toxoplasma exposure in schizophrenia have not been defined. Methods: We measured IgG class antibodies to Toxoplasma gondii in 358 individuals with schizophrenia. We correlated Toxoplasma antibody status with clinical and demographic variables and examined the effect of Toxoplasma seropositivity on mortality in a follow-up period of up to 5 years. Results: Individuals with schizophrenia who had serological evidence of Toxoplasma infection were more likely to be female but did not differ in age, race, total symptom score, or other demographic or clinical characteristics. However, we found that serological evidence of Toxoplasma was associated with a significantly increased risk of dying of natural causes during the follow-up period (Cox proportional hazard ratio of 4.70; 95% confidence interval, 1.27–17.31, P = .020) adjusted for age, gender, and other clinical and demographic variables. Conclusions: Toxoplasma infection may confer an increased risk for mortality from natural causes in schizophrenia. An understanding of the pathogenesis of Toxoplasma infections in individuals with schizophrenia might lead to new approaches to the management of this disorder. PMID:17314085

  14. Toxoplasma gondii in individuals with schizophrenia: association with clinical and demographic factors and with mortality.

    PubMed

    Dickerson, Faith; Boronow, John; Stallings, Cassie; Origoni, Andrea; Yolken, Robert

    2007-05-01

    Increased rates of exposure to Toxoplasma gondii have been found in individuals with schizophrenia as compared with control groups, but the correlates of Toxoplasma exposure in schizophrenia have not been defined. We measured IgG class antibodies to Toxoplasma gondii in 358 individuals with schizophrenia. We correlated Toxoplasma antibody status with clinical and demographic variables and examined the effect of Toxoplasma seropositivity on mortality in a follow-up period of up to 5 years. Individuals with schizophrenia who had serological evidence of Toxoplasma infection were more likely to be female but did not differ in age, race, total symptom score, or other demographic or clinical characteristics. However, we found that serological evidence of Toxoplasma was associated with a significantly increased risk of dying of natural causes during the follow-up period (Cox proportional hazard ratio of 4.70; 95% confidence interval, 1.27-17.31, P = .020) adjusted for age, gender, and other clinical and demographic variables. Toxoplasma infection may confer an increased risk for mortality from natural causes in schizophrenia. An understanding of the pathogenesis of Toxoplasma infections in individuals with schizophrenia might lead to new approaches to the management of this disorder.

  15. A Role for Activated Macrophages in Resistance to Infection with Toxoplasma

    PubMed Central

    Remington, Jack S.; Krahenbuhl, James L.; Mendenhall, Joy W.

    1972-01-01

    Activated macrophages from mice which were chronically infected with Toxoplasma gondii or Besnoitia jellisoni, or which had received Freund complete adjuvant, had an enhanced capacity to to kill intracellular Toxoplasma. Enhanced killing by activated macrophages was demonstrated by decreased incorporation of isotopically labeled uridine by intracellular Toxoplasma and by inhibition of plaque formation. The latter resulted from lack of proliferation of the intracellular Toxoplasma which is normally followed by destruction of the host cell (macrophage) and secondary invasion and destruction of fibroblast monolayers. Images PMID:4637298

  16. The Simplified Posterior Interosseous Flap.

    PubMed

    Cavadas, Pedro C; Thione, Alessandro; Rubí, Carlos

    2016-09-01

    Several technical modifications have been described to avoid complications and simplify dissection. The authors describe some technical tips that make posterior interosseous flap dissection safer and more straightforward. Copyright © 2016 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  17. Children's Understanding of Posterior Probability

    ERIC Educational Resources Information Center

    Girotto, Vittorio; Gonzalez, Michael

    2008-01-01

    Do young children have a basic intuition of posterior probability? Do they update their decisions and judgments in the light of new evidence? We hypothesized that they can do so extensionally, by considering and counting the various ways in which an event may or may not occur. The results reported in this paper showed that from the age of five,…

  18. Children's Understanding of Posterior Probability

    ERIC Educational Resources Information Center

    Girotto, Vittorio; Gonzalez, Michael

    2008-01-01

    Do young children have a basic intuition of posterior probability? Do they update their decisions and judgments in the light of new evidence? We hypothesized that they can do so extensionally, by considering and counting the various ways in which an event may or may not occur. The results reported in this paper showed that from the age of five,…

  19. Stereolithography for Posterior Fossa Cranioplasty

    PubMed Central

    Agner, Celso; Dujovny, Manuel; Evenhouse, Raymond; Charbel, Fady T.; Sadler, Lewis

    1998-01-01

    Posterior fossa cranioplasty has been suggested for improvement of neurological symptoms following craniectomy. However, there is no particular recommendation in the literature about techniques for prosthesis manufacture and implantation. We report our experience using rapid prototyping technology and stereolithography for pre-surgical implant design and production of cranioplasties. ImagesFigure 1Figure 2Figure 3Figure 4Figure 5 PMID:17171056

  20. 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...

  1. 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...

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

    NASA Astrophysics Data System (ADS)

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

    2008-12-01

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

  3. In vivo anti-Toxoplasma activity of aripiprazole

    PubMed Central

    Saraei, Mehrzad; Samadzadeh, Nafiseh; Khoeini, Javad; Shahnazi, Mojtaba; Nassiri-Asl, Marjan; Jahanihashemi, Hasan

    2015-01-01

    Objective(s): There are supportive evidences about the possible role of latent Toxoplasma. gondii infections on the behavior and neurologic functions, such as increased dopamine levels in the brain. The aim of this study was to examine anti-toxoplasma activity of aripiprazole that is an atypical anti-psychotic drug in mice. Materials and Methods: Mice were randomly divided into four groups, including; control, vehicle, aripiprazole 10 mg/kg, and aripiprazole 20 mg/kg. The mice were inoculated intraperitoneally with mice brain suspension containing tissue cysts. At the end of second month, the number of cysts was counted in smears prepared from brain homogenate by optical microscope. Results: There was no significant difference between mean logarithms of brain cyst numbers of aripiprazole groups compared with control. Conclusion: Results indicate that in aripiprazole groups, the brain cystogenesis was not decrease. Further study needs to investigate the role of anti-psychotic drugs on T. gondii. PMID:26523226

  4. Review of Experimental Compounds Demonstrating Anti-Toxoplasma Activity

    PubMed Central

    McFarland, Madalyn M.; Zach, Sydney J.; Wang, Xiaofang; Potluri, Lakshmi-Prasad; Neville, Andrew J.; Vennerstrom, Jonathan L.

    2016-01-01

    Toxoplasma gondii is a ubiquitous apicomplexan parasite capable of infecting humans and other animals. Current treatment options for T. gondii infection are limited and most have drawbacks, including high toxicity and low tolerability. Additionally, no FDA-approved treatments are available for pregnant women, a high-risk population due to transplacental infection. Therefore, the development of novel treatment options is needed. To aid this effort, this review highlights experimental compounds that, at a minimum, demonstrate inhibition of in vitro growth of T. gondii. When available, host cell toxicity and in vivo data are also discussed. The purpose of this review is to facilitate additional development of anti-Toxoplasma compounds and potentially to extend our knowledge of the parasite. PMID:27600037

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

    PubMed

    Hartley, M P

    2006-03-01

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

  6. Toxoplasma gondii pneumonia in immunocompetent subjects: case report and review.

    PubMed

    Leal, Fabio Eudes; Cavazzana, Cinthya Luzia; de Andrade, Heitor Franco; Galisteo, Andrés Jimenez; de Mendonça, João Silva; Kallas, Esper Georges

    2007-03-15

    Pulmonary toxoplasmosis is rare in immunocompetent subjects. Here, we describe a 41-year-old previously healthy male patient who presented to the emergency department of a hospital with a life-threatening case of pneumonia due to Toxoplasma gondii infection, which responded to specific therapy. Clinical and image-based findings overlap with those for atypical pneumonias, and toxoplasmosis should be considered in the differential diagnosis--especially if immunoglobulin M-specific antibodies are detected.

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

    PubMed

    Dubey, J P; Pas, An

    2008-05-06

    Fatal toxoplasmosis was diagnosed in a Blanford's fox (Vulpes cana) from the United Arab Emirates. Toxoplasma gondii-like tachyzoites were found associated with necrosis in intestine, spleen, liver, kidneys, lungs, skeletal muscle, brain and heart. Protozoal tachyzoites reacted positively with T. gondii-specific polyclonal antibodies. Antibodies to T. gondii were detected in 10 of 12 V. cana assayed by the latex agglutination or the modified direct agglutination test.

  8. Distortions of posterior visual space.

    PubMed

    Phillips, Flip; Voshell, Martin G

    2009-01-01

    The study of spatial vision is a long and well traveled road (which, of course, converges to a vanishing point at the horizon). Its various distortions have been widely investigated empirically, and most concentrate, pragmatically, on the space anterior to the observer. The visual world behind the observer has received relatively less attention and it is this perspective the current experiments address. Our results show systematic perceptual distortions in the posterior visual world when viewed statically. Under static viewing conditions, observer's perceptual representation was consistently 'spread' in a hyperbolic fashion. Directions to distant, peripheral locations were consistently overestimated by about 11 degrees from the ground truth and this variability increased as the target was moved toward the center of the observer's back. The perceptual representation of posterior visual space is, no doubt, secondary to the more immediate needs of the anterior visual world. Still, it is important in some domains including certain sports, such as rowing, and in vehicular navigation.

  9. Is Toxoplasma gondii a Trigger of Bipolar Disorder?

    PubMed Central

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

    2017-01-01

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

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

    PubMed Central

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

    2011-01-01

    Toxoplasmosis is caused by an intracellular protozoan, Toxoplasma gondii, which has a wide geographical distribution. The congenital form results in a gestational form that can present a temporary parasiteamia that will infect the fetus. For this reason early diagnosis in pregnancy is highly desirable, allowing prompt intervention in cases of infection. The aim of this study was to determine the seroprevalence of Toxoplasma gondii antibodies among pregnant women attending the Douala General Hospital. The study was carried out between March and July 2009, whereby 110 pregnant women were tested for IgG and IgM antibodies and information about eating habits and hygienic conditions was collected using a questionnaire. These women's ages ranged from 20–44 years old with an average of 29.9 years; the overall IgG and IgM seroprevalence was 70% and 2.73 % respectively. Seroprevalence was significantly high amongst women who ate raw vegetables (76.39%, P<0.05) and there was a significant trend towards a higher seroprevalence in women who did not have a good source of water (75.58%, P<0.05). This research showed that consumption of raw vegetables and poor quality drinking water are two risk factors associated with Toxoplasma gondii infection amongst pregnant women attending the Douala General Hospital in Cameroon. PMID:28299065

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

    PubMed

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

    2013-03-01

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

  12. Women infected with parasite Toxoplasma have more sons

    NASA Astrophysics Data System (ADS)

    Kaňková, Š.; Šulc, J.; Nouzová, K.; Fajfrlík, K.; Frynta, D.; Flegr, J.

    2007-02-01

    The boy-to-girl ratio at birth (secondary sex ratio) is around 0.51 in most populations. The sex ratio varies between societies and may be influenced by many factors, such as stress and immunosuppression, age, primiparity, the sex of the preceding siblings and the socioeconomic status of the parents. As parasite infection affects many immunological and physiological parameters of the host, we analyzed the effect of latent toxoplasmosis on sex ratios in humans. Clinical records of 1,803 infants born from 1996 to 2004 contained information regarding the mother’s age, concentration of anti- Toxoplasma antibodies, previous deliveries and abortions and the sex of the newborn. The results of our retrospective cohort study suggest that the presence of one of the most common parasites (with a worldwide prevalence from 20 to 80%), Toxoplasma gondii, can influence the secondary sex ratio in humans. Depending on the antibody concentration, the probability of the birth of a boy can increase up to a value of 0.72, C.I.95 = (0.636, 0.805), which means that for every 260 boys born, 100 girls are born to women with the highest concentration of anti- Toxoplasma antibodies. The toxoplasmosis associated with immunosuppression or immunomodulation might be responsible for the enhanced survival of male embryos. In light of the high prevalence of latent toxoplasmosis in most countries, the impact of toxoplasmosis on the human population might be considerable.

  13. Virus-Like Nanoparticle Vaccine Confers Protection against Toxoplasma gondii

    PubMed Central

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

    2016-01-01

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

  14. Virus-Like Nanoparticle Vaccine Confers Protection against Toxoplasma gondii.

    PubMed

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

    2016-01-01

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

  15. Seroprevalence of cytomegalovirus, toxoplasma and parvovirus in pregnancy.

    PubMed

    Wong, A; Tan, K H; Tee, C S; Yeo, G S

    2000-04-01

    The aim of our study was to determine the seroprevalence of cytomegalovirus (CMV), toxoplasma and parvovirus infection in our local antenatal population, and to see the effects, if any, of age, race, parity and nationality on its seroprevalence. The sera of 120 consecutive antenatal women seen in KK Women's and Children's Hospital between the period of October 1997 and March 1998 were screened for cytomegalovirus (CMV) IgG, toxoplasma IgG and parvovirus B19 IgG and IgM. An antibody titer greater than 1:32 was regarded as positive. A total of 87.0% of patients were tested seropositive for CMV IgG, 17.2% seropositive for toxoplasma IgG and 30.0% seropositive for parvovirus IgG. There seemed to be a trend of increasing seropositivity with age in all three groups, however only parovirus B19 reached statistical significance. The incidence of all three infections were higher among the Malays, Indians and other races compared to the Chinese. CMV is endemic in our population and hence the most common infection. Toxoplasmosis and parvovirus is relatively low in our population but this implies that a large proportion of our antenatal women are still susceptible to these infections. Prevention of congenital CMV, toxoplasmosis and parvovirus infection is mainly by educating the antenatal population.

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

    PubMed

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

    2014-06-01

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

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

    PubMed

    Dubey, J P

    1981-01-01

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

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

    USDA-ARS?s Scientific Manuscript database

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

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

    USDA-ARS?s Scientific Manuscript database

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

  20. Some factors influencing transmission of toxoplasma in pregnant rats fed cysts.

    PubMed

    Freyre, A; Correa, O; Falcón, J; Mendez, J; González, M; Venzal, J M

    2001-11-01

    An overall 44% transplacental transmission rate was observed in 221 rats fed cysts of 12 Toxoplasma strains at 15 days of pregnancy, with a range of 0-90% transmission. Considerable variability in the transmission rate was seen among different groups of rats that received similar Toxoplasma inocula; this is attributed to genetically based susceptibility to Toxoplasma among individuals of the outbred Wistar strain of rats. Transplacental transmission was more frequent in Long Evans than in Wistar rats. Significant differences in the rate of transmission were not found between rats that were fed similar Toxoplasma inocula 6-8 days or 15 days after conception. The frequency of transmission was not affected by the strain or dose of Toxoplasma used.

  1. [Clinical experience on treating Toxoplasma gondii infection during pregnancy by using acetyl spiramycin combined with azithromycin].

    PubMed

    Tang, Hong-xia; Xiong, Xue-feng; Qin, Zhi-qiang

    2013-10-01

    To explore an effective therapy for pregnant Toxoplasma gondii infection by using acetyl spiramycin combined with azithromycin. ELISA and PCR were used to diagnose and evaluate the therapy efficiency to toxoplasmosis in pregnant women. The serological test showed that the positive rates of specific antibodies IgM and IgG to Toxoplasma gondii in 285 pregnant women were 1.05% (3/285) and 5.97% (17/285), respectively. All the 3 cases of serum IgM positive pregnant women received the amniotic fluid PCR tests for Toxoplasma gondii DNA and 2 were positive, and they received spiramycin combined with azithromycin. After the therapy, their serum IgM antibody specific to Toxoplasma gondii and positive amniotic fluid PCR test for Toxoplasma gondii DNA turned to be negative. Acetyl spiramycin in combination with azithromycin is effective in the treatment of pregnant toxoplasmosis.

  2. Morbid attraction to leopard urine in Toxoplasma-infected chimpanzees.

    PubMed

    Poirotte, Clémence; Kappeler, Peter M; Ngoubangoye, Barthelemy; Bourgeois, Stéphanie; Moussodji, Maick; Charpentier, Marie J E

    2016-02-08

    Parasites are sometimes capable of inducing phenotypic changes in their hosts to improve transmission [1]. Toxoplasma gondii, a protozoan that infects a broad range of warm-blooded species, is one example that supports the so-called 'parasite manipulation hypothesis': it induces modifications in rodents' olfactory preferences, converting an innate aversion for cat odor into attraction and probably favoring trophic transmission to feline species, its only definitive hosts [2]. In humans, T. gondii induces behavioral modifications such as personality changes, prolonged reaction times and decreased long-term concentration [3]. However, modern humans are not suitable intermediate hosts because they are no longer preyed upon by felines. Consequently, behavioral modifications in infected people are generally assumed to be side effects of toxoplasmosis or residual manipulation traits that evolved in appropriate intermediate hosts. An alternative hypothesis, however, states that these changes result from parasite manipulative abilities that evolved when human ancestors were still under significant feline predation [3,4]. As such, T. gondii also alters olfactory preferences in humans; infected men rate cat urine, but not tiger urine, as pleasant while non-infected men do not [5]. To unravel the origin of Toxoplasma-induced modifications in humans, we performed olfactory tests on a living primate still predated by a feline species. We found in our closest relative, the chimpanzee (Pan troglodytes troglodytes), that Toxoplasma-infected (TI) animals lost their innate aversion towards the urine of leopards (Panthera pardus), their only natural predator. By contrast, we observed no clear difference in the response of TI and Toxoplasma-non-infected (TN) animals towards urine collected from other definitive feline hosts that chimpanzees do not encounter in nature. Although the adaptive value of parasitically induced behavior should be assessed carefully, we suggest that the

  3. Influence of latent Toxoplasma infection on human personality, physiology and morphology: pros and cons of the Toxoplasma-human model in studying the manipulation hypothesis.

    PubMed

    Flegr, Jaroslav

    2013-01-01

    The parasitic protozoan Toxoplasma gondii infects about one-third of the population of developed countries. The life-long presence of dormant stages of this parasite in the brain and muscular tissues of infected humans is usually considered asymptomatic from the clinical point of view. In the past 20 years, research performed mostly on military personnel, university students, pregnant women and blood donors has shown that this 'asymptomatic' disease has a large influence on various aspects of human life. Toxoplasma-infected subjects differ from uninfected controls in the personality profile estimated with two versions of Cattell's 16PF, Cloninger's TCI and Big Five questionnaires. Most of these differences increase with the length of time since the onset of infection, suggesting that Toxoplasma influences human personality rather than human personality influencing the probability of infection. Toxoplasmosis increases the reaction time of infected subjects, which can explain the increased probability of traffic accidents in infected subjects reported in three retrospective and one very large prospective case-control study. Latent toxoplasmosis is associated with immunosuppression, which might explain the increased probability of giving birth to a boy in Toxoplasma-infected women and also the extremely high prevalence of toxoplasmosis in mothers of children with Down syndrome. Toxoplasma-infected male students are about 3 cm taller than Toxoplasma-free subjects and their faces are rated by women as more masculine and dominant. These differences may be caused by an increased concentration of testosterone. Toxoplasma also appears to be involved in the initiation of more severe forms of schizophrenia. At least 40 studies confirmed an increased prevalence of toxoplasmosis among schizophrenic patients. Toxoplasma-infected schizophrenic patients differ from Toxoplasma-free schizophrenic patients by brain anatomy and by a higher intensity of the positive symptoms of the

  4. [Posterior reversible encephalopathy: beyond the original description].

    PubMed

    Avecillas-Chasín, Josué M; Matías-Guiu, Jordi A; Bautista-Balbás, Luis

    2015-07-16

    Introduccion. La encefalopatia posterior reversible (EPR) es una entidad clinicorradiologica caracterizada tipicamente por cuadros de cefalea, alteraciones visuales y crisis epilepticas, asociada a edema vasogeno corticosubcortical reversible en la neuroimagen. Objetivo. Presentar una revision de los aspectos fisiopatologicos de esta entidad y tambien de las asociaciones de la EPR descritas en la bibliografia. Desarrollo. Existe una serie de factores desencadenantes bien conocidos, como las crisis hipertensivas, la eclampsia o ciertos medicamentos. La descripcion de cada vez mas casos atipicos desde un punto de vista clinico y radiologico, asi como de posibles nuevos factores desencadenantes, obliga a una redefinicion de la entidad. Conclusiones. La EPR es un conjunto de manifestaciones clinicas y radiologicas que no se pueden enmarcar dentro la palabra 'sindrome'. Aunque la EPR se ha comunicado como irreversible en ciertos casos, el concepto de reversibilidad debe mantenerse en la definicion de esta entidad, ya que, en la mayor parte de los casos, el rapido control de la condicion desencadenante de la EPR permite la reversibilidad de las lesiones.

  5. Posterior commissure of the human larynx revisited.

    PubMed

    Tucker, John A; Tucker, Sean T

    2010-05-01

    The existence of the posterior commissure (PC) of the human larynx has been disputed (Hirano M, Sato K, et al. The posterior glottis. Trans Am Laryngol Assoc. 1986;107:70-75). "The term posterior commissure has no relevance to anatomical structure. The term commissure means a joining together. The bilateral vocal folds never join at their posterior ends. The posterior aspect of the glottis is a wall. The posterior lateral aspect of the posterior glottis is also the lateral wall of the posterior glottis" (Hirano M, Sato K, et al. The posterior glottis. Trans Am Laryngol Assoc. 1986;107:70-75). This study is intended to clarify the development of anatomical and morphological aspects of the PC in conjunction with a clinical classification of the larynx in sagittal view. This study uses human embryo and fetal laryngeal sections from the Carnegie Collection of Human Embryos (the world standard) and whole organ laryngeal sections from the Tucker Laryngeal Fetal Collection. Correlation of histologic and gross anatomical structure is made with the Hirano et al atlas, the Vidić Photographic Atlas of the Human Body, and the O'Rahilly Embryonic Atlas. Embryologic data clearly describe and illustrate the posterior union of the cricoid cartilage with formation of the PC. The anatomical functional aspects of the posterior lateral cricoid lamina as the supporting buttress of the articulating arytenoid cartilages are illustrated.

  6. Isolated posterior cruciate ligament calcification

    PubMed Central

    Koukoulias, Nikolaos E; Papastergiou, Stergios G

    2011-01-01

    The authors present a case of calcified posterior cruciate ligament (PCL). A 61-year-old female presented in our department reporting 12 months history of knee pain that was getting worse during the night. The patient was under medication for epileptic seizure, osteoporosis and hyperthyroidism. X-rays demonstrated calcification of the PCL. CT and MRI excluded any other intra-articular and extra-articular pathology. Arthroscopic debridement of the calcium deposits was performed and the symptoms resolved immediately, while the postoperative x-rays were normal. Histological examination confirmed the calcium nature of the lesion. Two years postoperatively the patient remains asymptomatic. PMID:22669889

  7. Posterior tibial slope and femoral sizing affect posterior cruciate ligament tension in posterior cruciate-retaining total knee arthroplasty.

    PubMed

    Kuriyama, Shinichi; Ishikawa, Masahiro; Nakamura, Shinichiro; Furu, Moritoshi; Ito, Hiromu; Matsuda, Shuichi

    2015-08-01

    During cruciate-retaining total knee arthroplasty, surgeons sometimes encounter increased tension of the posterior cruciate ligament. This study investigated the effects of femoral size, posterior tibial slope, and rotational alignment of the femoral and tibial components on forces at the posterior cruciate ligament in cruciate-retaining total knee arthroplasty using a musculoskeletal computer simulation. Forces at the posterior cruciate ligament were assessed with the standard femoral component, as well as with 2-mm upsizing and 2-mm downsizing in the anterior-posterior dimension. These forces were also determined with posterior tibial slope angles of 5°, 7°, and 9°, and lastly, were measured in 5° increments when the femoral (tibial) components were positioned from 5° (15°) of internal rotation to 5° (15°) of external rotation. Forces at the posterior cruciate ligament increased by up to 718N with the standard procedure during squatting. The 2-mm downsizing of the femoral component decreased the force at the posterior cruciate ligament by up to 47%. The 2° increment in posterior tibial slope decreased the force at the posterior cruciate ligament by up to 41%. In addition, posterior cruciate ligament tension increased by 11% during internal rotation of the femoral component, and increased by 18% during external rotation of the tibial component. These findings suggest that accurate sizing and bone preparation are very important to maintain posterior cruciate ligament forces in cruciate-retaining total knee arthroplasty. Care should also be taken regarding malrotation of the femoral and tibial components because this increases posterior cruciate ligament tension. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Foraminotomia cervical posterior en el tratamiento de conflictos foraminales

    PubMed Central

    Campero, Álvaro; Barrera, Ramiro; Ajler, Pablo

    2012-01-01

    Introducción: La foraminomotima cervical posterior es un procedimiento utilizado para la descompresion radicular por via posterior y constituye una alternativa a la via clásica anterior. En este trabajo evaluamos nuestra serie de pacientes tratados por esta via. Método: Desde enero de 2008 a diciembre de 2011, 17 pacientes (18 foraminotomías) fueron operados por presentar cervicobraquialgia a causa de un conflicto foraminal, realizando un foraminotomía cervical posterior. Los pacientes fueron evaluados en el postoperatorio inmediato, al mes y a los 3 meses de la cirugía. Los parámetros para valorar los resultados fueron la Escala Análoga del Dolor (VAS), la Neck Disability Index y los criterios de Odom. Resultados: El dolor radicular por conflicto foraminal secundario a hernia de disco cervical fue el síntoma y la patología predominante. El nivel más afectado fue C5-C6. La resolución completa del dolor radicular se observó en casi todos los pacientes. La VAS preoperatoria en promedio fue de 8.8 (mínimo 8 – máximo 10), con una franca mejoría en todos los casos (0.4 en el último control). La media en la Neck Disability Index al inicio fue de 35.3 (mínimo 32 – máximo 45), con una evolución favorable en la evaluación final (0.6). Los Criterios de Odom para la evaluación de pacientes operados de columna cervical fueron satisfactorios con un promedio de 1.17. Se observaron complicaciones en 4 pacientes (23%), todas tuvieron una evolución favorable. No hubo infecciones, discitis ni empeoramiento de los síntomas preexistentes en ningún paciente. Conclusión: La foraminotomía cervical posterior es un procedimiento efectivo para el tratamiento del dolor radicular en los conflictos foraminales PMID:23596556

  9. Huge interparietal posterior fontanel meningohydroencephalocele

    PubMed Central

    Dos Santos, Manuel Filipe Dias; de Santa Barbara, Rita de Cassia

    2015-01-01

    Congenital encephalocele is a neural tube defect characterized by a sac-like protrusion of the brain, meninges, and other intracranial structures through the skull, which is caused by an embryonic development abnormality. The most common location is at the occipital bone, and its incidence varies according to different world regions. We report a case of an 1-month and 7-day-old male child with a huge interparietal-posterior fontanel meningohydroencephalocele, a rare occurrence. Physical examination and volumetric computed tomography were diagnostic. The encephalocele was surgically resected. Intradural and extradural approaches were performed; the bone defect was not primarily closed. Two days after surgery, the patient developed hydrocephaly requiring ventriculoperitoneal shunting. The surgical treatment of the meningohydroencephalocele of the interparietal-posterior fontanel may be accompanied by technical challenges and followed by complications due to the presence of large blood vessels under the overlying skin. In these cases, huge sacs herniate through large bone defects including meninges, brain, and blood vessels. The latter present communication with the superior sagittal sinus and ventricular system. A favorable surgical outcome generally follows an accurate strategy taking into account individual features of the lesion. PMID:26484324

  10. Longevity of Posterior Composite Restorations

    PubMed Central

    Opdam, N.J.M.; van de Sande, F.H.; Bronkhorst, E.; Cenci, M.S.; Bottenberg, P.; Pallesen, U.; Gaengler, P.; Lindberg, A.; Huysmans, M.C.D.N.J.M.; van Dijken, J.W.

    2014-01-01

    The aim of this meta-analysis, based on individual participant data from several studies, was to investigate the influence of patient-, materials-, and tooth-related variables on the survival of posterior resin composite restorations. Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we conducted a search resulting in 12 longitudinal studies of direct posterior resin composite restorations with at least 5 years’ follow-up. Original datasets were still available, including placement/failure/censoring of restorations, restored surfaces, materials used, reasons for clinical failure, and caries-risk status. A database including all restorations was constructed, and a multivariate Cox regression method was used to analyze variables of interest [patient (age; gender; caries-risk status), jaw (upper; lower), number of restored surfaces, resin composite and adhesive materials, and use of glass-ionomer cement as base/liner (present or absent)]. The hazard ratios with respective 95% confidence intervals were determined, and annual failure rates were calculated for subgroups. Of all restorations, 2,816 (2,585 Class II and 231 Class I) were included in the analysis, of which 569 failed during the observation period. Main reasons for failure were caries and fracture. The regression analyses showed a significantly higher risk of failure for restorations in high-caries-risk individuals and those with a higher number of restored surfaces. PMID:25048250

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

    PubMed

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

    2016-05-01

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

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

    PubMed

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

    2016-04-01

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

  13. Significance of a Positive Toxoplasma Immunoglobulin M Test Result in the United States.

    PubMed

    Dhakal, Reshika; Gajurel, Kiran; Pomares, Christelle; Talucod, Jeanne; Press, Cynthia J; Montoya, Jose G

    2015-11-01

    A positive Toxoplasma immunoglobulin M (IgM) result is often interpreted as a marker of an acute infection. However, IgM can persist for several years, and Toxoplasma commercial IgM diagnostic test kits can yield a number of false-positive results. For these reasons, a chronic Toxoplasma infection can be erroneously classified as an acute infection, resulting in serious adverse consequences, especially in pregnant women, leading to emotional distress and unnecessary interventions, including termination of pregnancy. Interpretation of Toxoplasma serology at a reference laboratory can help differentiate a recently acquired infection from a chronic infection. Serological test results for 451 patients with positive Toxoplasma IgM and IgG test results obtained at nonreference laboratories (NRLs) that were referred to Palo Alto Medical Foundation Toxoplasma Serology Laboratory (PAMF-TSL) to determine whether the patient was acutely or chronically infected were retrospectively reviewed. PAMF-TSL results established that of the 451 patients, 335 (74%) had a chronic infection, 100 (22%) had an acute infection, and 7 (2%) were not infected, and for 9 (2%), results were indeterminate. Positive Toxoplasma IgM and IgG test results obtained at NRLs cannot accurately distinguish between acute and chronic infections. To do so, testing at reference laboratories is required, as mandated in 1997 in a letter from the Food and Drug Administration (FDA) to clinicians and laboratories in the United States.

  14. Detection of Acanthamoeba and Toxoplasma in River Water Samples by Molecular Methods in Iran

    PubMed Central

    MAHMOUDI, Mohammad Reza; KAZEMI, Bahram; HAGHIGHI, Ali; KARANIS, Panagiotis

    2015-01-01

    Background: Free-living amoebae such as Acanthamoeba species may act as carriers of Cryptosporidium and Toxoplasma oocysts, thus, may play an important role in the water-borne transmission of these parasites. In the present study, a loop mediated isothermal amplification (LAMP) method for detection of Toxoplasma and a PCR assay were developed for investigation of Acanthamoeba in environmental water samples. Methods: A total of 34 samples were collected from the surface water in Guilan Province. Water samples were filtrated with membrane filters and followed by DNA extraction. PCR and LAMP methods used for detection of the protozoan parasites Acanthamoeba and Toxoplasma respectively. Results: Totally 30 and 2 of 34 samples were positive for Acanthamoeba and Toxoplasma oocysts respectively. Two samples were positive for both investigated parasites. Conclusion: The investigated water supplies, are contaminated by Toxoplasma and Acanthamoeba (oo)cystes. Acanthamoeba may play an important role in water-borne transmission of Toxoplasma in the study area. For the first time in Iran, protocol of LAMP method was used effectively for the detection of Toxoplasma in surface water samples in Iran. PMID:26246823

  15. Significance of a Positive Toxoplasma Immunoglobulin M Test Result in the United States

    PubMed Central

    Gajurel, Kiran; Pomares, Christelle; Talucod, Jeanne; Press, Cynthia J.

    2015-01-01

    A positive Toxoplasma immunoglobulin M (IgM) result is often interpreted as a marker of an acute infection. However, IgM can persist for several years, and Toxoplasma commercial IgM diagnostic test kits can yield a number of false-positive results. For these reasons, a chronic Toxoplasma infection can be erroneously classified as an acute infection, resulting in serious adverse consequences, especially in pregnant women, leading to emotional distress and unnecessary interventions, including termination of pregnancy. Interpretation of Toxoplasma serology at a reference laboratory can help differentiate a recently acquired infection from a chronic infection. Serological test results for 451 patients with positive Toxoplasma IgM and IgG test results obtained at nonreference laboratories (NRLs) that were referred to Palo Alto Medical Foundation Toxoplasma Serology Laboratory (PAMF-TSL) to determine whether the patient was acutely or chronically infected were retrospectively reviewed. PAMF-TSL results established that of the 451 patients, 335 (74%) had a chronic infection, 100 (22%) had an acute infection, and 7 (2%) were not infected, and for 9 (2%), results were indeterminate. Positive Toxoplasma IgM and IgG test results obtained at NRLs cannot accurately distinguish between acute and chronic infections. To do so, testing at reference laboratories is required, as mandated in 1997 in a letter from the Food and Drug Administration (FDA) to clinicians and laboratories in the United States. PMID:26354818

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

    PubMed Central

    Reyes, L; Frenkel, J K

    1987-01-01

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

  17. Early detection of Toxoplasma gondii-infected cats by interferon-gamma release assay.

    PubMed

    Yin, Qing; El-Ashram, Saeed; Liu, Xian-Yong; Suo, Xun

    2015-10-01

    Felines, the only definitive hosts that shed the environmentally-durable oocysts, are the key in the transmission of Toxoplasma gondii to all warm-blooded animals. They seroconvert as late as the third week and begin to shed oocysts as early as 3-8 days after being fed tissue cysts. Early detection of Toxoplasma-infected cats is crucial to evaluate Toxoplasma-contaminated environment and potential risks to public health. Moreover, it is fundamental for Toxoplasma infection control. Interferon-gamma release assay (IGRA) is a blood-based test assessing the presence of IFN-γ released by the T-lymphocytes directed against specific antigens, which is an ideal assay for early detection of Toxoplasma-infected cats. Here, cats were orally infected with the tissue cysts and blood was collected for toxoplasmic antigen stimulation, and the released IFN-γ was measured by ELISA. Results showed that Toxoplasma-infection was detected by IGRA as early as 4 days post-infection (dpi); while serum Toxoplasma IgM and IgG were detected by ELISA at 10 dpi and 14 dpi, respectively. Our findings demonstrated that IGRA-positive and ELISA-negative samples revealed an early Toxoplasma infection in cats, indicating a new strategy for the early diagnosis of Toxoplasma infection by combining IGRA and ELISA. Therefore, IGRA could emerge as a reliable diagnostic tool for the exploration of cat toxoplasmosis prevalence and its potential risks to public health. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. Antenatal screening for Toxoplasma gondii, Cytomegalovirus, rubella and Treponema pallidum infections in northern Benin.

    PubMed

    De Paschale, Massimo; Ceriani, Cristina; Cerulli, Teresa; Cagnin, Debora; Cavallari, Serena; Cianflone, Annalisa; Diombo, Kouma; Ndayaké, Joseph; Aouanou, Guy; Zaongo, Dieudonné; Priuli, Gianbattista; Viganò, Paolo; Clerici, Pierangelo

    2014-06-01

    Toxoplasma gondii, cytomegalovirus (HCMV) and rubella virus infections are among the most serious of those contracted during pregnancy in terms of foetal consequences. Toxoplasma, HCMV and rubella antibody screening is unusual in Africa, and there are few published data. The aim of this study was to evaluate the prevalence of these markers among pregnant women in northern Benin on the occasion of routine syphilis screening. Toxoplasma, HCMV and rubella IgG and IgM antibodies were determined in the serum of 283 women attending Saint Jean de Dieu de Tanguiéta hospital, using an enzyme immunoassay, and IgM were confirmed using an enzyme-linked fluorescent assay (ELFA). In the case of IgM positivity, the avidity of anti-HCMV and anti-Toxoplasma IgG was measured. Total anti-Treponema pallidum antibodies were determined using an enzyme immunoassay and confirmed by immunoblotting. In the case of positivity, the Venereal Disease Research Laboratory (VDRL) test was used. The prevalence of anti-Toxoplasma, anti-HCMV, anti-rubella IgG and total anti-Treponema antibodies was, respectively, 30.0%, 100%, 94% and 2.5%. The VDRL test was positive in 62.5% of the anti-Treponema-positive samples. The prevalence of anti-Toxoplasma, anti-HCMV and anti-rubella IgM was, respectively, 0.4%, 1.4% and 0%. There were no statistically significant differences in terms of age class or trimester of pregnancy. Anti-Toxoplasma and anti-HCMV IgG avidity was always high. The prevalence of HCMV and rubella antibodies is high in northern Benin, whereas that of Toxoplasma antibodies is lower. As nearly two-thirds of the pregnant women were anti-Toxoplasma seronegative, antibody screening should be introduced. © 2014 John Wiley & Sons Ltd.

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

    PubMed

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

    2013-04-01

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

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

    PubMed

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

    1997-04-01

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

  1. Toxoplasma antibodies among bobcats and other carnivores of norther California.

    PubMed

    Riemann, H P; Howarth, J A; Ruppanner, R; Franti, C E; BEHYMER, D E

    1975-04-01

    The prevalence of antibodies to Toxoplasma gondii was investigated among five species of wild carnivores in Norther Ccalifornia. The highest prevalence was among bobcats (Lynx rufus), with 15 of 21 tested being serologically positive. Other results included serological evidence of toxoplasmosis in two of seven raccoons (Procyon lotor), one of three badgers (taxidea taxus) and two of three coyotes (Canis latrans). Two gray foxes (Urocyon cinereoargenteus) were serologically negative. Oone badger with an indirect hemagglutination antibody titer of 1:8192 was found to harbor T. gondii in its brain tissues.

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

    PubMed

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

    2013-02-18

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

  3. Lifelong Persistence of Toxoplasma Cysts: A Questionable Dogma?

    PubMed

    Rougier, Solène; Montoya, Jose G; Peyron, François

    2017-02-01

    It is believed that infection by Toxoplasma gondii triggers a lifelong protective immunity due to the persistence of parasitic cysts which induce immunoprotection against reinfection. A review of the scientific literature since the 1950s did not yield any definitive data regarding the duration of cysts in the host or the presence of lifelong protective immunity, which led us to question this dogma. We put forward the hypothesis that sustained immunity to T. gondii requires repeated antigenic stimulations. The decline of seroprevalence recently observed in many countries might contribute to explain the loss of immunity. We address the potential consequences of this phenomenon, should it persist and worsen.

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

    PubMed

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

    2001-09-01

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

  5. Biological and molecular characterizations of Toxoplasma gondii strains

    USGS Publications Warehouse

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

    2000-01-01

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

  6. 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

  7. Psychiatric Disorders in Toxoplasma Seropositive Patients—The CD8 Connection

    PubMed Central

    Khan, Imtiaz A.

    2013-01-01

    Although the highest numbers of studies linking an infectious agent with schizophrenia has involved the parasite Toxoplasma gondii, the mechanistic underpinnings of this correlation has remained unaddressed. Incidentally, CD8 T cells, which play a pivotal role in mediating long-term immunity to Toxoplasma, are downregulated in schizophrenia patients. Recent studies have demonstrated that CD8 response is also impaired during chronic toxoplasmosis in murine models. In light of these new findings, in this article, we discuss the potential role of CD8 T cells in causing altered mental status in Toxoplasma seropositive schizophrenia patients. PMID:23427221

  8. Toxoplasma encephalitis in a HIV patient: unusual involvement of the corpus callosum.

    PubMed

    Supiot, F; Guillaume, M P; Hermanus, N; Telerman-Toppet, N; Karmali, R

    1997-12-01

    In patients with acquired immuno-deficiency syndrome, the differential diagnosis between primary brain lymphoma and toxoplasma encephalitis is not radiologically always straightforward, especially in the presence of a solitary cerebral lesion. In this context, involvement of the corpus callosum is almost exclusively associated with primary brain lymphoma. We describe here an HIV-infected patient who presented with a single and large cerebral lesion affecting the corpus callosum, suggestive of primary brain lymphoma on MRI-scan but who nonetheless responded clinically and radiologically to an anti-toxoplasma drug trial confirming the diagnosis of toxoplasma encephalitis.

  9. Comparative study on Toxoplasma infection between Malaysian and Myanmar pregnant women.

    PubMed

    Andiappan, Hemah; Nissapatorn, Veeranoot; Sawangjaroen, Nongyao; Nyunt, Myat Htut; Lau, Yee-Ling; Khaing, Si Lay; Aye, Khin Myo; Mon, Nan Cho Nwe; Tan, Tian-Chye; Kumar, Thulasi; Onichandran, Subashini; bin Mat Adenan, Noor Azmi

    2014-12-12

    Toxoplasma gondii, an obligate intracellular protozoan parasite, causes a disease called toxoplasmosis which can sometimes be acquired congenitally by a newborn from an infected mother. This study aimed to determine the seroprevalence of Toxoplasma infection and its associated risks among 219 and 215 pregnant women from Malaysia and Myanmar, respectively. Anti-Toxoplasma IgG and IgM antibodies were screened by using standard commercial ELISA kits. The socio-demographic, obstetrics and risk factors associated with Toxoplasma infection data were compared between the two countries. The overall prevalence of Toxoplasma infection in Malaysian pregnant women (42.47%; 95% CI = 36.11-49.09) was significantly higher (p < 0.05) than Myanmar pregnant women (30.70%; 95% CI = 27.92-37.16). By univariate analysis, this study identified that age group, education, parity, awareness on toxoplasmosis and consumption of undercooked meat were significantly associated (p < 0.05) with Toxoplasma seropositive Malaysian pregnant women but none of these factors associated with Toxoplasma seropositive Myanmar pregnant women. In comparison using univariate analysis between the two countries, it was found that Toxoplasma seropositive Malaysian pregnant women was associated with aged 30 years and above, secondary or lower-secondary level of education, the third trimester of pregnancy, having one child or more, lacking awareness of toxoplasmosis, absence of bad obstetrics history, having no history of close contact with cats or soil, living on a farm and also consumption of undercooked meat, unpasterized milk or untreated water. Avidity measurement was used to confirm the stages of Toxoplasma infection in pregnant women who were positive for both IgG and IgM antibodies and found all were infected in the past. From our study, Toxoplasma screening and its risk measurement in pregnant women is firmly recommended for monitoring purposes and assisting proper management, including diagnosis and

  10. The early years of Toxoplasma research: What’s past is prologue

    PubMed Central

    Morrissette, Naomi S.; Ajioka, James W.

    2009-01-01

    In the century since the first description of Toxoplasma gondii, history and circumstance have led scientists to define this organism in diverse contexts. From its discovery by researchers shaped by early 20th century versions of the germ theory to its more recent roles as an important globally distributed pathogen and a model apicomplexan, our definitions of Toxoplasma are as much a reflection of our frame of reference as they are an absolute definition of this organism. Although these transformations act as portals for new avenues of investigation, the essential questions that inform current research are founded in the work of early investigators who studied Toxoplasma. PMID:19250939

  11. Posterior peritoneal recesses: assessment using CT

    SciTech Connect

    Rubenstein, W.A.; Auh, Y.H.; Zirinsky, K.; Kneeland, J.B.; Whalen, J.P.; Kazam, E.

    1985-08-01

    Intraperitoneal compartments may extend posteriorly to the level of known retroperitoneal structures at several locations within the abdomen. These locations include the posterior subhepatic or hepatorenal space, the splenorenal space, the retropancreatic recess, the paracolic gutters, and the pararectal fossae. Because of their posterior location, fluid collections within these compartments may be mistaken radiologically for retroperitoneal masses. The sectional anatomy of these spaces and particularly their appearance on computed tomographic scans, are illustrated in this paper.

  12. Posterior ankle impingement in the dancer.

    PubMed

    Moser, Brad R

    2011-01-01

    Dancers spend a lot of time in the relevé position in demi-pointe and en pointe in their training and their careers. Pain from both osseous and soft tissue causes may start to occur in the posterior aspect of their ankle. This article reviews the potential causes of posterior ankle impingement in dancers. It will discuss the clinical evaluation of a dancer and the appropriate workup and radiographic studies needed to further evaluate a dancer with suspected posterior ankle impingement.

  13. Imaging of the Posterior Skull Base.

    PubMed

    Job, Joici; Branstetter, Barton F

    2017-01-01

    The posterior skull base can be involved by a variety of pathologic processes. They can be broadly classified as: traumatic, neoplastic, vascular, and inflammatory. Pathology in the posterior skull base usually involves the lower cranial nerves, either as a source of pathology or a secondary source of symptoms. This review will categorize pathology arising in the posterior skull base and describe how it affects the skull base itself and surrounding structures. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. The posterior reversible encephalopathy syndrome.

    PubMed

    Sanjay, K Mandal; Partha, P Chakraborty

    2008-09-01

    The posterior/potentially reversible encephalopathy syndrome is a unique syndrome encountered commonly in hypertensive encephalopathy. A 13-year-old boy presented with of intermittent high grade fever, throbbing headache and non-projective vomiting for 5 days. The patient had a blood pressure of 120/80 mmHg but fundoscopy documented grade 3 hypertensive retinopathy. The patient improved symptomatically following conservative management. However, on the 5(th) post-admission day headache reappeared, and blood pressure measured at that time was 240/120 mmHg. Neuroimaging suggested white matter abnormalities. Search for the etiology of secondary hypertension led to the diagnosis of pheochromocytoma. Repeated MRI after successful surgical excision of the tumor patient showed reversal of white matter abnormalities. Reversible leucoencephalopathy due to pheochromocytoma have not been documented in literature previously.

  15. Identification, production and assessment of two Toxoplasma gondii recombinant proteins for use in a Toxoplasma IgG avidity assay.

    PubMed

    Teh, Ai Ying; Amerizadeh, Atefeh; Osman, Sabariah; Yunus, Muhammad Hafiznur; Noordin, Rahmah

    The IgG avidity assay is an important tool in the management of suspected toxoplasmosis in pregnant women. This study aimed to produce new Toxoplasma gondii recombinant proteins and to assess their usefulness in an IgG avidity assay. Toxoplasma positive and negative serum samples were used, the former were categorized into low (LGA) and high (HGA) IgG avidity samples. Immunoblots were performed on 30 T. gondii cDNA clones to determine the reactivity and IgG avidity to the expressed proteins. Two of the clones were found to have diagnostic potential and were analyzed further; AG12b encoded T. gondii apical complex lysine methyltransferase (AKMT) protein and AG18 encoded T. gondii forkhead-associated (FHA) domain-containing protein. The His-tagged recombinant proteins, rAG12b and rAG18, were expressed and tested with LGA and HGA samples using an IgG avidity western blot and ELISA. With the IgG avidity western blot, rAG12b identified 86.4% of LGA and 90.9% of HGA samples, whereas rAG18 identified 81.8% of both LGA and HGA samples. With the IgG avidity ELISA, rAG12b identified 86.4% of both LGA and HGA samples, whereas rAG18 identified 77.3% of LGA and 86.4% of HGA serum samples. This study showed that the recombinant antigens were able to differentiate low avidity and high avidity serum samples, suggesting that they are potential candidates for use in the Toxoplasma IgG avidity assay.

  16. Toxoplasma gondii Ingests and Digests Host Cytosolic Proteins

    PubMed Central

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

    2014-01-01

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

  17. 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'.

  18. Nucleotide variation in the Toxoplasma gondii micronemal protein 8 gene.

    PubMed

    Li, Z Y; Song, H Q; Wang, C R; Zhu, X Q

    2016-05-09

    Toxoplasma gondii is a successful opportunistic protozoan distributed worldwide, which can infect all vertebrates, leading to serious infection, blindness, and abortion. Micronemal (MIC) proteins are critically important for T. gondii infection, as they participate in various stages of the Toxoplasma life cycle, including invasion and attachment to host cells. MIC8 secretion relies on the concentration of intracellular calcium, and can mediate the invasion of T. gondii by interacting with soluble MIC3. To investigate genetic diversity of the MIC8 gene, 16 T. gondii strains from different hosts and geographical locations, and two reference isolates (ToxoDB: TGME49_245490 and TGVEG_245490) were examined in this study. The results showed that all the examined MIC8 genes are 2055 bp, with an A+T content ranging from 50.2 to 50.6%. Conversely, lower levels of variation were detected within their nucleotide and amino acid sequences. Phylogenetic analyses indicated that three classical genotypes of T. gondii and the ToxoDB#9 genotype did not group exclusively via Bayesian inference, maximum parsimony, neighbor joining, and/or maximum likelihood assays based on the nucleotide and amino acid sequences of the MIC8 gene. In summary, the T. gondii MIC8 gene is not a suitable marker for population genetic studies of this parasite.

  19. Identification of new Palmitoylated Proteins in Toxoplasma gondii

    PubMed Central

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

    2016-01-01

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

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

    PubMed

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

    2017-02-16

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

  1. Evidence for high levels of vertical transmission in Toxoplasma gondii.

    PubMed

    Hide, G; Morley, E K; Hughes, J M; Gerwash, O; Elmahaishi, M S; Elmahaishi, K H; Thomasson, D; Wright, E A; Williams, R H; Murphy, R G; Smith, J E

    2009-12-01

    Toxoplasma gondii is a highly ubiquitous and prevalent parasite. Despite the cat being the only definitive host, it is found in almost all geographical areas and warm blooded animals. Three routes of transmission are recognised: ingestion of oocysts shed by the cat, carnivory and congenital transmission. In natural populations, it is difficult to establish the relative importance of these routes. This paper reviews recent work in our laboratory which suggests that congenital transmission may be much more important than previously thought. Using PCR detection of the parasite, studies in sheep show that congenital transmission may occur in as many as 66% of pregnancies. Furthermore, in families of sheep on the same farm, exposed to the same sources of oocysts, significant divergent prevalences of Toxoplasma infection and abortion are found between different families. The data suggest that breeding from infected ewes increases the risk of subsequent abortion and infection in lambs. Congenital transmission rates in a natural population of mice were found to be 75%. Interestingly, congenital transmission rates in humans were measured at 19.8%. The results presented in these studies differ from those of other published studies and suggest that vertical transmission may be much more important than previously thought.

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

    PubMed

    Dubey, J P

    2002-08-01

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

  3. Mitochondrial behaviour throughout the lytic cycle of Toxoplasma gondii

    PubMed Central

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

    2017-01-01

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

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

    PubMed

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

    2009-02-01

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

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

    PubMed

    Anquetin, Guillaume; Greiner, Jacques; Vierling, Pierre

    2005-09-01

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

  6. 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...

  7. Tissue tropism and parasite burden of Toxoplasma gondii RH strain in experimentally infected mice.

    PubMed

    Dadimoghaddam, Yousef; Daryani, Ahmad; Sharif, Mehdi; Ahmadpour, Ehsan; Hossienikhah, Zahra

    2014-07-01

    To evaluate parasite distribution and tissue tropism of Toxoplasma gondii tachyzoites in experimentally infected mice using real time QPCR. In this survey 16 Balb/c mice were inoculated with 1 × 10(4) alive tachyzoites of Toxoplasma gondii RH strain. After 1, 2, 3 days post infection and the last day (before death), different tissues of mice including blood, brain, eye, liver, spleen, kidney, heart and muscle were harvested. Following tissues DNA extraction, the parasite burden was quantified using real time QPCR targeting the B1 gene (451 bp). It showed that Toxoplasma after intraperitoneal injection was able to movement to various tissues in 24 hours. Parasite burden was high in all tissues but the most number of parasites were observed in kidney, heart and liver, respectively. These data provide significant baseline information about Toxoplasma pathogenesis, vaccine monitoring and drug efficiency. Copyright © 2014 Hainan Medical College. Published by Elsevier B.V. All rights reserved.

  8. 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.

  9. 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...

  10. 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...

  11. Evaluation of a Candidate International Standard Preparation for Human Anti-Toxoplasma Immunoglobulin G

    PubMed Central

    Rigsby, Peter; Rijpkema, Sjoerd; Guy, Edward C.; Francis, Janet; Gaines Das, Rose

    2004-01-01

    A freeze-dried human serum preparation containing immunoglobulin G (IgG) to Toxoplasma gondii was assessed for its suitability as an international reference reagent in an international collaborative study by 24 laboratories from 17 countries. This candidate standard was compared with the third international standard (IS) for human anti-Toxoplasma serum, TOXM, with the previous second IS, TOXS, and with a range of other serum samples. Samples were tested with the Sabin-Feldman dye test and a range of agglutination assays and enzyme immunoassays. This study emphasizes the need for appropriate standards if intermethod agreement of estimates is to be achieved. On the basis of the results of this study, the preparation was established by the World Health Organization as the first IS for human anti-Toxoplasma IgG, with an assigned potency of 20 IU per ampoule of total anti-Toxoplasma antibodies. PMID:15528706

  12. 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...

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

    PubMed Central

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

    1981-01-01

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

  14. Consistently inconsistent, the posterior vaginal wall.

    PubMed

    Hale, Douglass S; Fenner, Dee

    2016-03-01

    Posterior vaginal wall prolapse is one of the most common prolapses encountered by gynecological surgeons. What appears to be a straightforward condition to diagnose and treat surgically for physicians has proven to be frustratingly unpredictable with regard to symptom relief for patients. Functional disorders such as dyssynergic defecation and constipation are often attributed to posterior vaginal wall prolapse. Little scientific evidence supports this assumption, emphasizing that structure and function are not synonymous when treating posterior vaginal wall prolapse. Rectoceles, enteroceles, sigmoidoceles, peritoneoceles, rectal and intraanal intussusception, rectal prolapse, and descending perineal syndrome are all conditions that have an impact on the posterior vaginal wall. All too often these different anatomic conditions are treated with the same surgical approach, addressing a posterior vaginal wall bulge with a traditional posterior colporrhaphy. Studies that examine the correlation between stage of posterior wall prolapse and patient symptoms have failed to reliably do so. Surgical outcomes measured by prolapse staging appear successful, yet patient expectations are often not met. As increasing attention is being placed on patient satisfaction outcomes concerning surgical treatments, this fact will need to be addressed. Surgeons will have to clearly communicate what can and what cannot be expected with surgical repair of posterior vaginal wall prolapse. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. Developmental abnormalities of the posterior pituitary gland.

    PubMed

    di Iorgi, Natascia; Secco, Andrea; Napoli, Flavia; Calandra, Erika; Rossi, Andrea; Maghnie, Mohamad

    2009-01-01

    While the molecular mechanisms of anterior pituitary development are now better understood than in the past, both in animals and in humans, little is known about the mechanisms regulating posterior pituitary development. The posterior pituitary gland is formed by the evagination of neural tissue from the floor of the third ventricle. It consists of the distal axons of the hypothalamic magnocellular neurones that shape the neurohypophysis. After its downward migration, it is encapsulated together with the ascending ectodermal cells of Rathke's pouch which form the anterior pituitary. By the end of the first trimester, this development is completed and vasopressin and oxytocin can be detected in neurohypophyseal tissue. Abnormal posterior pituitary migration such as the ectopic posterior pituitary lobe appearing at the level of median eminence or along the pituitary stalk have been reported in idiopathic GH deficiency or in subjects with HESX1, LHX4 and SOX3 gene mutations. Another intriguing feature of abnormal posterior pituitary development involves genetic forms of posterior pituitary neurodegeneration that have been reported in autosomal-dominant central diabetes insipidus and Wolfram disease. Defining the phenotype of the posterior pituitary gland can have significant clinical implications for management and counseling, as well as providing considerable insight into normal and abnormal mechanisms of posterior pituitary development in humans.

  16. Restoration of Toxoplasma gondii-specific immune responses in patients with AIDS starting HAART.

    PubMed

    Furco, André; Carmagnat, Maryvonnick; Chevret, Sylvie; Garin, Yves J-F; Pavie, Juliette; De Castro, Nathalie; Charron, Dominique; Derouin, Francis; Rabian, Claire; Molina, Jean-Michel

    2008-10-18

    To study the kinetics and identify factors associated with Toxoplasma-specific immune responses in patients with AIDS starting antiretroviral therapy. A prospective study of 38 HIV-infected patients seropositive for Toxoplasma who started antiretroviral therapy with CD4 T cells less than 200 cells/microl. T-cell and B-cell phenotypes, anti-Toxoplasma antibodies titers, Th-1 and Th-2 cytokine production and lymphocyte proliferative responses (LPRs) to Toxoplasma were assessed over 12 months. Median CD4 cell count increased from 122 cells/microl at baseline to 260 cells/microl at 12 months, and the incidence of a positive LPR from 18.4 to 70.5%. A Toxoplasma IgG titer more than 150 IU/ml was the only baseline variable associated with a positive LPR (hazard ratio: 4.6, P = 0.003). Among time-dependent covariates, the number of effector memory (CD45RA-CCR7-) CD4 T cells was associated with a positive LPR (P < 0.02) and the number of terminally differentiated (CD45RA+CCR7-) CD8 T cells was associated with in-vitro production of gamma-IFN (P < 0.008). Among patients with low CD4 cell counts, high anti-Toxoplasma IgG titers were associated with LPR to Toxoplasma antigen. After starting antiretroviral therapy, the number of effector memory CD4 T cells and terminally differentiated CD8 T cells were associated with the restoration of Toxoplasma LPR and gamma-IFN production, respectively.

  17. Toxoplasma gondii Serology and Outcomes After Heart Transplantation: Contention in the Literature.

    PubMed

    Chehrazi-Raffle, A; Luu, M; Yu, Z; Liou, F; Kittleson, M; Hamilton, M; Kobashigawa, J

    2015-01-01

    Toxoplasma gondii is an endemic pathogen to which approximately half of healthy patients develop antibodies. Toxoplasma serology is routinely assessed prior to heart transplantation. It has been suggested that donor or recipient toxoplasma serologic status may be associated with poor long-term outcomes post-transplantation, but current literature reveals conflicting results. From 1995 to 2012 at our single center, we retrospectively reviewed 785 heart transplant patients for pre-transplantation T. gondii serology. Patients were divided into T. gondii seronegative and seropositive groups. Subgroups in each group were created based on whether the donor was seropositive or seronegative. We assessed survival, freedom from nonfatal major adverse cardiac events, and freedom from cardiac allograft vasculopathy at 5 years post-transplantation. No significant difference was found between 5-year outcomes of pre-transplant T. gondii seronegative and T. gondii seropositive recipients post-heart transplantation. However, in the donor-seropositive/recipient-seronegative subgroup (D+/R-), there was a significantly lower 5-year survival rate compared to the cohort of donor-seronegative/recipient-seronegative (D-/R-) patients (60% vs 87%, P = .04). After adjustment by multivariate analysis, D+/R- status conferred a trend towards increased mortality (HR 3.0, P = .06). Toxoplasma serology prior to heart transplantation does not appear to impact post-transplantation outcome. However, toxoplasma seronegative patients who receive toxoplasma seropositive hearts appear to have poorer 5-year survival compared to toxoplasma seronegative patients who received toxoplasma seronegative hearts. Due to the small sample size, the association between T. gondii serology mismatch and long-term survival warrants further study. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. Impact of ApoE genotypes variations on Toxoplasma patients with dementia.

    PubMed

    Yahya, Raida S; Awad, Soha I; El-Baz, Hatim A; Saudy, Niveen; Abdelsalam, Osama A; Al-Din, Mohamed S Shehab

    2017-05-01

    Toxoplasma deprives host neuron cells from cholesterol and leads to its ability to potentiate dementia. ApoE intermediates neuronal transmission of cholesterol, which is a key constituent for axonal development, redesigning occasions that are important for education and synaptic arrangement, development of memory and repair of neuron. The aim of this work is to investigate the effect of ApoE genotypes on dementia associated with neurodegeneration in latent Toxoplasma gondii in elderly population. This study comprised: 133 patients with dementia (78 were positive for toxoplasma IgG and 55 were negative) and 95 subjects as control group without dementia (30 were positive for toxoplasma IgG and 65 were negative). All of them were subjected to a cognitive assessment, T. gondii seropositivity (ELISA) and determination of ApoE allelic forms (PCR). The ApoE genotype distribution shows that the most predominant genotype is ApoE3/3 and the most widely recognized allele is E3. Both patients and control were further divided into Toxoplasma IgG positive group (n=108) and Toxoplasma IgG negative group (n=120). ApoE4 non carrier, ApoE 2/3 and ApoE 3/3 alleles have highly significant differences (P<0.001) between dementia and non-dementia patients in Toxoplasma infected patients in comparison to non-infected ones. Toxoplasma positive patients have more risk to develop dementia regardless ApoE4 carriage. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. The organization of the wall filaments and characterization of the matrix structures of Toxoplasma gondii cyst form.

    PubMed

    Lemgruber, Leandro; Lupetti, Pietro; Martins-Duarte, Erica S; De Souza, Wanderley; Vommaro, Rossiane C

    2011-12-01

    The encystation process is a key step in Toxoplasma gondii life cycle, allowing the parasite to escape from the host immune system and the transmission among the hosts. A detailed characterization of the formation and structure of the cyst stage is essential for a better knowledge of toxoplasmosis. Here we isolated cysts from mice brains and analysed the cyst wall structure and cyst matrix organization using different electron microscopy techniques. Images obtained showed that the cyst wall presented a filamentous aspect, with circular openings on its surface. The filaments were organized in two layers: a compact one, facing the exterior of the whole cyst and a more loosen one, facing the matrix. Within the cyst wall, we observed tubules and a large number of vesicles. The cyst matrix presented vesicles of different sizes and tubules, which were organized in a network connecting the bradyzoites to each other and to the cyst wall. Large vesicles, with a granular material in their lumen of glycidic nature were observed. Similar vesicles were also found associated with the posterior pole of the bradyzoites and in proximity to the cyst wall. © 2011 Blackwell Publishing Ltd.

  20. Unilateral posterior crossbite and mastication.

    PubMed

    Rilo, Benito; da Silva, José Luis; Mora, María Jesús; Cadarso-Suárez, Carmen; Santana, Urbano

    2007-05-01

    This study was designed to characterize masticatory-cycle morphology, and distance of the contact glide in the closing masticatory stroke, in adult subjects with uncorrected unilateral posterior crossbite (UPXB), comparing the results obtained with those obtained in a parallel group of normal subjects. Mandibular movements (masticatory movements and laterality movements with dental contact) were registered using a gnathograph (MK-6I Diagnostic System) during unilateral chewing of a piece of gum. Traces were recorded on the crossbite and non-crossbite sides in the crossbite group, and likewise on both sides in the non-crossbite group. Mean contact glide distance on the crossbite side in the UPXB group was significantly lower than in the control group (p<0.001), and mean contact glide distance on the non-crossbite side in the UPXB group was significantly lower than in the control group (p=0.042). Cycle morphology was abnormal during chewing on the crossbite side, with the frequency distribution of cycle types differing significantly from that for the noncrossbite side and that for the control group (p<0.001). Patients with crossbite showed alterations in both contact glide distances and masticatory cycle morphology. These alterations are probably adaptive responses allowing maintenance of adequate masticatory function despite the crossbite.

  1. [Posterior uveitis: sarcoidosis or tuberculosis].

    PubMed

    Ness, T; Virchow, J C

    2001-02-01

    To demonstrate the difficulties of the differential diagnosis between tuberculosis and sarcoidosis as the cause of posterior uveitis. A 56-year-old woman suffered from bilateral anterior uveitis, snow-ball like infiltrates in the vitreous, and peripheral retinochoroidal granulomas with marked exudation shown in fluorescein angiography. Angiotensin-converting enzyme, as a marker of sarcoidosis, was elevated; the tuberculin test, however, was negative. Chest X-ray revealed an infiltrate and numerous smaller granulomas. The presumptive diagnosis was sarcoidosis. Surprisingly, in the biopsy of the pulmonal lesion tubercle bacilli were detected by Ziehl-Neelsen staining. Thus, a diagnosis of pulmonal and also retinochoroidal tuberculosis was made. After tuberculostatic therapy the choroidal lesions healed off. In a second case, a 30-year-old man suffered from bilateral panuveitis with candle wax exudates near the retinal vessels. Chest X-ray revealed lymphomas in the hilus, and the lymph node biopsy showed granulomas with epitheloid cells, indicating sarcoidosis. Detection of mycobacterium tuberculosis by culture or histological criteria was negative. Only in the PCR was mycobacterium tuberculosis DNA detectable. Tuberculostatic therapy had no benefit. Under therapy with steroids, however, pulmonal and ophthalmologic findings rapidly disappeared. The difficult differential diagnosis between sarcoidosis and tuberculosis cannot always be made by laboratory tests or diagnostic imaging alone. Clinical manifestations, including response to therapy, are essential.

  2. Posterior repair and sexual function

    PubMed Central

    Komesu, Yuko M.; Rogers, Rebecca G.; Kammerer-Doak, Dorothy N.; Barber, Matthew D.; Olsen, Ambre L.

    2011-01-01

    OBJECTIVE The purpose of this study was to determine the effect of posterior repair (PR) on sexual function in patients who have undergone incontinence and/or pelvic reconstructive surgery. STUDY DESIGN A cohort study of women who underwent incontinence and/or prolapse surgery was performed. Participants completed the pelvic organ prolapse urinary incontinence sexual questionnaire (PISQ) before and after the operation. PISQ scores were compared between women who underwent PR and women who did not. RESULTS Of 73 study participants, 30 women underwent PR; 43 women did not (no PR). Although there was no difference in dyspareunia between groups pre-op, dyspareunia prevalence post-op was significantly lower in the no PR group. Preoperative PISQ scores were similar between groups. After the operation, both groups significantly improved their PISQ scores, without a difference between groups. CONCLUSION Although the incidence of dyspareunia differed between PR and no PR groups, overall improvement in sexual function was reflected in improved total PISQ scores that occurred irrespective of PR performance. PMID:17618777

  3. Reconstruction of posterior trunk defects.

    PubMed

    Ramasastry, S S; Schlechter, B; Cohen, M

    1995-01-01

    A high rate of success can be expected in the management of posterior trunk defects with muscle flaps. The surgeon has to adhere closely to the basic reconstructive principles of adequate debridement of all necrotic or devitalized tissues; management of infection with local wound care and appropriate antibiotic therapy; and coverage with well-vascularized tissue to obliterate any residual dead space and to cover bone grafts, orthopedic hardware, and vital structures such as the dura and spinal cord. Flap selection is also of paramount importance for success, and only muscles with appropriate arc of rotation, vascularity (vascular pedicles outside the field of radiation injury, or intact vascularity following previous procedures) and bulk should be used. Adequate flap mobilization to obtain a tension-free closure and judicious use of drains and perioperative antibiotic agents are essential. Occasionally, microvascular free-tissue transfer may be necessary if local flaps are unavailable. The complications of flap reconstruction include partial flap loss, persistent dead space for lack of adequate muscle bulk, and persistent infection. Debridement and re-advancement of the flap is adequate in most cases. If there is significant or total flap loss, however, a second flap reconstruction is often necessary to obliterate the dead space and protect vital structures.

  4. Pig and herd level prevalence of Toxoplasma gondii in Ontario finisher pigs in 2001, 2003, and 2004

    PubMed Central

    Poljak, Zvonimir; Dewey, Catherine E.; Friendship, Robert M.; Martin, S. Wayne; Christensen, Jette; Ojkic, Davor; Wu, John; Chow, Eva

    2008-01-01

    The objective of this study was to estimate the apparent and true prevalence of exposure to Toxoplasma gondii in Ontario finisher pigs. During the study period (2001 to 2004), sera from 6048 pigs were tested with a commercial enzyme-linked immunosorbent assay (ELISA); 103 farms were included 1 to 3 times in the study. True prevalence was estimated using a Bayesian approach. Apparent prevalence at the pig level was 1.59% [95% confidence interval (CI): 0.45, 2.99] in 2001, 0.06% (95% CI: 0.00, 0.46) in 2003, and 0.26% (95% CI: 0.00, 0.82) in 2004. Apparent prevalence at the herd-level was 13.7% (95% CI: 7.5, 22.3) in 2001; 1.25% (95% CI: 0.03, 6.77) in 2003, and 3.75% (95% CI: 0.78, 10.6) in 2004. Similarly, posterior Bayesian estimates of true prevalence at the pig level were 1.7% [95% probability interval (PI): 1.2, 2.2] in 2001, 0.2% (95% PI: 0.04, 0.4) in 2003, and 0.3% (95% PI: 0.1, 0.7) in 2004. At the herd level, posterior estimates of prevalence were 11.6% (95% PI: 7.4, 16.8) in 2001, 0% (95% PI: 0.0, 2.5) in 2003, and 1.2% (95% PI: 0.0, 5.0) in 2004 when a herd cut-point ≥ 1 was used. Exposure to T. gondii in finishing pig farms in Ontario appears to be infrequent. PMID:18783018

  5. Meibography for eyes with posterior blepharitis.

    PubMed

    AlDarrab, Abdulrahman; Alrajeh, Mohammed; Alsuhaibani, Adel H

    2017-01-01

    To study the effect of posterior blepharitis on meibomian glands using infrared meibography and to correlate the results with tear film parameters. This is a prospective cohort study. The study included eyes from two groups: 86 eyes of healthy volunteers' eyes and 72 eyes with posterior blepharitis. Participants were examined, and diagnosis of posterior blepharitis was achieved clinically based on signs of posterior blepharitis. Clinical assessment of dryness was performed including slit lamp examination looking for signs of posterior blepharitis, tear breakup time (TBUT), superficial punctate keratopathy (SPK), Schirmer II test (with anesthesia) and meibum score. Non-contact meibography was performed for both upper and lower eyelids using the meibo-grade system which involved distortion of meibomian gland, shortening and dropout. Lid margin abnormalities (Telangiectasia, lid margin swelling and hyperemia) were all significantly higher in the posterior blepharitis group. SPK, meibum score, meibography dropout, distortion, shortening, and total meibography were all significantly higher in the posterior blepharitis group as well as meibum score (P value < 0.001). TBUT was significantly shorter in the posterior blepharitis group (P value < 0.001). There was no significant difference between the two groups in Schirmer's II test. Meibography can be a helpful non-invasive tool for the clinical evaluation of the extent of the anatomical damage in patients having meibomian glands loss due to posterior blepharitis. Knowing the extent of damage in meibomian glands may help in selecting the appropriate treatment modality and expect the response to treatment in patients with posterior blepharitis.

  6. Predator cat odors activate sexual arousal pathways in brains of Toxoplasma gondii infected rats.

    PubMed

    House, Patrick K; Vyas, Ajai; Sapolsky, Robert

    2011-01-01

    Cat odors induce rapid, innate and stereotyped defensive behaviors in rats at first exposure, a presumed response to the evolutionary pressures of predation. Bizarrely, rats infected with the brain parasite Toxoplasma gondii approach the cat odors they typically avoid. Since the protozoan Toxoplasma requires the cat to sexually reproduce, this change in host behavior is thought to be a remarkable example of a parasite manipulating a mammalian host for its own benefit. Toxoplasma does not influence host response to non-feline predator odor nor does it alter behavior on olfactory, social, fear or anxiety tests, arguing for specific manipulation in the processing of cat odor. We report that Toxoplasma infection alters neural activity in limbic brain areas necessary for innate defensive behavior in response to cat odor. Moreover, Toxoplasma increases activity in nearby limbic regions of sexual attraction when the rat is exposed to cat urine, compelling evidence that Toxoplasma overwhelms the innate fear response by causing, in its stead, a type of sexual attraction to the normally aversive cat odor.

  7. Cyst burden in the brains of Wistar rats fed Toxoplasma oocysts.

    PubMed

    Freyre, A; Falcón, J; Correa, O; Mendez, J; González, M; Venzal, J M; Morgades, D

    2003-03-01

    Six strains of Toxoplasma oocysts were used to infect groups of 4-24 Wistar rats, with each rat being fed 10(1)-10(4) oocysts from a single strain. After 2 months, the rats were killed, their brains screened for Toxoplasma cysts and then bioassayed in mice if negative. Toxoplasma was either observed in the form of brain cysts or was recovered using the bioassay, from 113 out of 138 (82%) rat brains. As few as ten oocysts were capable of initiating a brain infection that lasted for at least 2 months in eight of the nine rats inoculated. However, judging from bioassay 10(2)-10(4) oocysts did not give rise to progressively higher rates of infection. Brain cysts were seen in only 68 of 138 rats (49%). The number of Toxoplasma cysts formed in the brains of rats was generally in the order of tens to hundreds. The frequency of infection in the brains with Toxoplasma and the number of brain cysts formed appeared to be influenced by the individual resistance of the rats as well as by the doses of oocysts and the Toxoplasma strains used. The information gathered is considered to be a basis for a rat model of immunity against acquired toxoplasmosis.

  8. Posterior microphthalmos, retinitis pigmentosa and optic disc drusen with white dots. A case report.

    PubMed

    Plaza, P; Iturralde, O; Abascal, C

    2017-05-13

    To present the case of a patient with a posterior microphthalmos-optic disc drusen-retinitis pigmentosa syndrome associated, for the first time, with white dots in the posterior pole. The posterior microphthalmos, retinitis pigmentosa and optic disc drusen syndrome was described for the first time in literature in 1991. Later, it was associated with a pattern of foveal thickening and/or foveoschisis. Different forms of mutations on chromosomes 11 and 14 have been identified as being responsible for the appearance of this syndrome, but the inheritance pattern is unknown. The case is reported of a 37 year-old man, with no personal or family history of interest, diagnosed with this syndrome in association with white dots in the posterior pole. Such a morphological association has never been published before in literature. The posterior microphthalmos, retinitis pigmentosa and optic disc drusen syndrome is a very rare entity, and has never been described associated with white dots in the posterior pole. More case reports are needed to establish clear patterns of both the disease and inheritance. Copyright © 2017 Sociedad Española de Oftalmología. Publicado por Elsevier España, S.L.U. All rights reserved.

  9. Contrasting Effect of Prepulse Signals on Performance of Toxoplasma-Infected and Toxoplasma-Free Subjects in an Acoustic Reaction Times Test

    PubMed Central

    Příplatová, Lenka; Šebánková, Blanka; Flegr, Jaroslav

    2014-01-01

    Background About 30% of people on Earth have latent toxoplasmosis. Infected subjects do not express any clinical symptoms, however, they carry dormant stages of parasite Toxoplasma for the rest of their life. This form of toxoplasmosis is mostly considered harmless, however, recent studies showed its specific effects on physiology, behaviour and its associations with various diseases, including psychiatric disorders such as schizophrenia. Individuals who suffer from schizophrenia have about 2.7 times higher prevalence of Toxoplasma-seropositivity than controls, which suggests that some traits characteristic of schizophrenic patients, including the sex difference in schizophrenia onset, decrease of grey matter density in specific brain areas and modification of prepulse inhibition of startle reaction could in fact be caused by toxoplasmosis for those patients who are Toxoplasma-seropositive. Methodology/Principal Findings We measured the effect of prepulse inhibition/facilitation of the startle reaction on reaction times. The students, 170 women and 66 men, were asked to react as quickly as possible to a startling acoustic signal by pressing a computer mouse button. Some of the startling signals were without the prepulse, some were 20 msec. preceded by a short (20 msec.) prepulse signal of lower intensity. Toxoplasma-seropositive subjects had longer reaction times than the controls. Acoustic prepulse shorted the reaction times in all subjects. This effect of prepulse on reaction times was stronger in male subjects and increased with the duration of infection, suggesting that it represented a cumulative effect of latent toxoplasmosis, rather than a fading out after effect of past acute toxoplasmosis. Conclusions Different sensitivity of Toxoplasma-seropositive and Toxoplasma-seronegative subjects on effect of prepulses on reaction times (the toxoplasmosis-prepulse interaction) suggested, but of course did not prove, that the alternations of prepulse inhibition of

  10. Recurrent posterior shoulder instability. Diagnosis and treatment.

    PubMed

    Pollock, R G; Bigliani, L U

    1993-06-01

    Recurrent posterior glenohumeral instability is regarded as a difficult problem to diagnose and treat. A careful history and physical examination are the most helpful tools in making this diagnosis. A positive posterior stress test, demonstrable posterior subluxation, and a sulcus sign are frequently present on examination. Special roentgenographic studies, such as the computerized arthrotomography (arthro-CT) scan, may be used in cases in which plain roentgenographs suggest bony glenoid abnormalities. When conservative therapy fails, there is no consensus on the operative treatment. Procedures that address the soft tissues, such as capsulorrhaphy and posterior labral repair, as well as those that alter the bony geometry of the joint, such as posterior bone blocks and glenoid or humeral osteotomies, have been described. Capsular laxity is the most common pathologic finding in the authors' experience, and they favor the use of a posterior-inferior capsular shift procedure to correct this problem. Augmentation of the repair with a posterior bone block is reserved for unusual cases, such as when glenoid hypoplasia is present or in certain revision situations.

  11. Posterior labral injury in contact athletes.

    PubMed

    Mair, S D; Zarzour, R H; Speer, K P

    1998-01-01

    Nine athletes (seven football offensive linemen, one defensive lineman, and one lacrosse player) were found at arthroscopy to have posterior labral detachment from the glenoid. In our series, this lesion is specific to contact athletes who engage their opponents with arms in front of the body. All patients had pain with bench pressing and while participating in their sport, diminishing their ability to play effectively. Conservative measures were ineffective in relieving their symptoms. Examination under anesthesia revealed symmetric glenohumeral translation bilaterally, without evidence of posterior instability. Treatment consisted of glenoid rim abradement and posterior labral repair with a bioabsorbable tack. All patients returned to complete at least one full season of contact sports and weightlifting without pain (minimum follow-up, > or = 2 years). Although many injuries leading to subluxation of the glenohumeral joint occur when an unanticipated force is applied, contact athletes ready their shoulder muscles in anticipation of impact with opponents. This leads to a compressive force at the glenohumeral joint. We hypothesize that, in combination with a posteriorly directed force at impact, the resultant vector is a shearing force to the posterior labrum and articular surface. Repeated exposure leads to posterior labral detachment without capsular injury. Posterior labral reattachment provides consistently good results, allowing the athlete to return to competition.

  12. Congenital basis of posterior fossa anomalies

    PubMed Central

    Cotes, Claudia; Bonfante, Eliana; Lazor, Jillian; Jadhav, Siddharth; Caldas, Maria; Swischuk, Leonard

    2015-01-01

    The classification of posterior fossa congenital anomalies has been a controversial topic. Advances in genetics and imaging have allowed a better understanding of the embryologic development of these abnormalities. A new classification schema correlates the embryologic, morphologic, and genetic bases of these anomalies in order to better distinguish and describe them. Although they provide a better understanding of the clinical aspects and genetics of these disorders, it is crucial for the radiologist to be able to diagnose the congenital posterior fossa anomalies based on their morphology, since neuroimaging is usually the initial step when these disorders are suspected. We divide the most common posterior fossa congenital anomalies into two groups: 1) hindbrain malformations, including diseases with cerebellar or vermian agenesis, aplasia or hypoplasia and cystic posterior fossa anomalies; and 2) cranial vault malformations. In addition, we will review the embryologic development of the posterior fossa and, from the perspective of embryonic development, will describe the imaging appearance of congenital posterior fossa anomalies. Knowledge of the developmental bases of these malformations facilitates detection of the morphological changes identified on imaging, allowing accurate differentiation and diagnosis of congenital posterior fossa anomalies. PMID:26246090

  13. Treatment implications of posterior fossa ependymoma subgroups.

    PubMed

    Ramaswamy, Vijay; Taylor, Michael D

    2016-11-15

    Posterior fossa ependymoma comprises two distinct molecular entities, ependymoma_posterior fossa A (EPN_PFA) and ependymoma_posterior fossa B (EPN_PFB), with differentiable gene expression profiles. As yet, the response of the two entities to treatment is unclear. To determine the relationship between the two molecular subgroups of posterior fossa ependymoma and treatment, we studied a cohort of 820 patients with molecularly profiled, clinically annotated posterior fossa ependymomas. We found that the strongest predictor of poor outcome in patients with posterior fossa ependymoma across the entire age spectrum was molecular subgroup EPN_PFA, which was recently reported in the paper entitled "Therapeutic impact of cytoreductive surgery and irradiation of posterior fossa ependymoma in the molecular era: a retrospective multicohort analysis" in the Journal of Clinical Oncology. Patients with incompletely resected EPN_PFA tumors had a very poor outcome despite receiving adjuvant radiation therapy, whereas a substantial proportion of patients with EPN_PFB tumors can be cured with surgery alone.

  14. Outcome of Posterior Tibial Plateau Fixation.

    PubMed

    Jiwanlal, Aneel; Jeray, Kyle James

    2016-01-01

    Isolated posterior tibial plateau fractures are rare injuries that encompass a wide variety of fracture patterns. Based on the variation in fracture pattern, the surgical approach varies, with both anterior and posterior approaches described for surgical fixation. Postoperative protocol also varies among studies. The aim of this article is to summarize the outcomes related to posterior column tibial plateau fractures. The papers reviewed, primarily small retrospective case series, showed functional knee range of motion is preserved, a low incidence of wound complications, and patient outcome scores comparable to other reported lower extremity injury outcome scores. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  15. 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.

  16. Toxoplasma gondii Exposure and the Risk of Schizophrenia

    PubMed Central

    Khademvatan, Shahram; Saki, Jasem; Khajeddin, Niloufar; Izadi-Mazidi, Maryam; Beladi, Reza; Shafiee, Behnaz; Salehi, Zahra

    2014-01-01

    Background: Schizophrenia is a major psychiatric disorder with a deeply destructive pathophysiology. There are evidences to indicate that infectious agents such as Toxoplasma gondii may play some roles in etiology of the disorder. Objectives: The current study aimed to determine the association between T. gondii exposure and the risk of schizophrenia. Materials and Methods: T. gondii IgG antibodies of 100 patients with schizophrenia as well as 200 healthy volunteers were assessed. The subjects also completed demographic questionnaires. Data was analyzed using the chi-square and Fisher exact tests. Results: The analyses confirmed the significant differences between healthy women and ones with schizophrenia (P = 0.001) as well as between males and females with schizophrenia (P = 0.009) in IgG positivity. Conclusions: The present study supported the contamination with T. gondii as a risk factor for schizophrenia just in women. PMID:25774275

  17. The schizophrenia and Toxoplasma gondii connection: infectious, immune or both?

    PubMed

    Tamer, Gulden Sonmez; Dundar, Devrim; Yalug, Irem; Caliskan, Seyda; Yazar, Suleyman; Aker, Ahmet

    2008-07-01

    Recent research has suggested a possible link between toxoplasmic agents and schizophrenia. We aimed to assess this by measuring Toxoplasma gondii-associated antibodies in schizophrenia patients and controls We used a commercially available enzyme-linked immunosorbent assay (ELISA) kit to measure the level of immunoglobulin G (IgG) and IgM antibodies in serum samples from schizophrenia patients (n=40) and from a group of non-schizophrenic control subjects (n=37) Among schizophrenic patients, 16 (40%) showed IgG seropositivity and two (5%) showed IgM seropositivity. Among the control group, five (13.5%) were found have IgG seropositivity and one (2.7%) showed IgM seropositivity. In our study we found that IgG T gondii antibodies were significantly higher in schizophrenia patients compared with controls This study supports the theory that toxoplasmic agents may have a role in the aetiology of schizophrenia.

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

    PubMed

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

    2014-03-01

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

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed Central

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

    2015-01-01

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

  1. 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.

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

    PubMed

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

    2013-02-01

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

  3. Bartonella and Toxoplasma infections in stray cats from Iraq.

    PubMed

    Switzer, Alexandra D; McMillan-Cole, Audrey C; Kasten, Rickie W; Stuckey, Matthew J; Kass, Philip H; Chomel, Bruno B

    2013-12-01

    Because of overpopulation, stray/feral cats were captured on military bases in Iraq as part of the US Army Zoonotic Disease Surveillance Program. Blood samples were collected from 207 cats, mainly in Baghdad but also in North and West Iraq, to determine the prevalence of Bartonella and Toxoplasma infections. Nine (4.3%) cats, all from Baghdad, were bacteremic with B. henselae type I. Seroprevalence was 30.4% for T. gondii, 15% for B. henselae, and 12.6% for B. clarridgeiae. Differences in Bartonella prevalence by location were statistically significant, because most of the seropositive cats were from Baghdad. There was no association between T. gondii seropositivity and either of the two Bartonella species surveyed. This report is the first report on the prevalence of Bartonella and T. gondii among stray cats in Iraq, which allows for better evaluation of the zoonotic risk potential to the Iraqi people and deployed military personnel by feral cat colonies.

  4. Modulation of innate immunity by Toxoplasma gondii virulence effectors

    PubMed Central

    Hunter, Christopher A.; Sibley, L. David

    2013-01-01

    Preface Toxoplasma gondii is a common parasite of animals and humans that can cause serious opportunistic infections. However, the majority of infections are asymptomatic possibly because the organism has co-evolved with its many vertebrate hosts and has developed multiple strategies to persist asymptomatically for the lifetime of the host. Over the past two decades, infection studies in the mouse, combined with forward genetic approaches aimed at unraveling the molecular basis of infection, have revealed that T. gondii virulence is mediated, in part, by secretion of effector proteins into the host cell during invasion. Here, we review recent advances that illustrate how these virulence factors disarm innate immunity and promote survival of the parasite. PMID:23070557

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

    PubMed

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

    2013-03-01

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

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

    PubMed

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

    2013-03-31

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

  7. Clinically Available Medicines Demonstrating Anti-Toxoplasma Activity

    PubMed Central

    Neville, Andrew J.; Zach, Sydney J.; Wang, Xiaofang; Larson, Joshua J.; Judge, Abigail K.; Davis, Lisa A.; Vennerstrom, Jonathan L.

    2015-01-01

    Toxoplasma gondii is an apicomplexan parasite of humans and other mammals, including livestock and companion animals. While chemotherapeutic regimens, including pyrimethamine and sulfadiazine regimens, ameliorate acute or recrudescent disease such as toxoplasmic encephalitis or ocular toxoplasmosis, these drugs are often toxic to the host. Moreover, no approved options are available to treat infected women who are pregnant. Lastly, no drug regimen has shown the ability to eradicate the chronic stage of infection, which is characterized by chemoresistant intracellular cysts that persist for the life of the host. In an effort to promote additional chemotherapeutic options, we now evaluate clinically available drugs that have shown efficacy in disease models but which lack clinical case reports. Ideally, less-toxic treatments for the acute disease can be identified and developed, with an additional goal of cyst clearance from human and animal hosts. PMID:26392504

  8. Fatal Toxoplasma gondii infection in the giant panda

    PubMed Central

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

    2015-01-01

    Toxoplasma gondii can infect nearly all warm-blooded animals. We report an acute fatal T. gondii infection in the endangered giant panda (Ailuropoda melanoleuca) in a zoo in China, characterized by acute gastroenteritis and respiratory symptoms. T. gondii infection was confirmed by immunological and molecular methods. Multilocus nested PCR-RFLP revealed clonal type I at the SAG1 and c29-2 loci, clonal type II at the SAG2, BTUB, GRA6, c22-8, and L358 loci, and clonal type III at the alternative SAG2 and SAG3 loci, thus, a potential new genotype of T. gondii in the giant panda. Other possible pathogens were not detected. To our knowledge, this is the first report of clinical toxoplasmosis in a giant panda. PMID:26514595

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

    PubMed Central

    Boucher, Lauren E.; Bosch, Jürgen

    2014-01-01

    The apicomplexan parasite Toxoplasma gondii must invade host cells to continue its lifecycle. It invades different cell types using an actomyosin motor that is connected to extracellular adhesins via the bridging protein fructose-1,6-­bisphosphate aldolase. During invasion, aldolase serves in the role of a structural bridging protein, as opposed to its normal enzymatic role in the glycolysis pathway. Crystal structures of the homologous Plasmodium falciparum fructose-1,6-bisphosphate aldolase have been described previously. Here, T. gondii fructose-1,6-bisphosphate aldolase has been crystallized in space group P22121, with the biologically relevant tetramer in the asymmetric unit, and the structure has been determined via molecular replacement to a resolution of 2.0 Å. An analysis of the quality of the model and of the differences between the four chains in the asymmetric unit and a comparison between the T. gondii and P. falciparum aldolase structures is presented. PMID:25195889

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

    PubMed

    Vyas, Ajai

    2015-01-01

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

  11. Bartonella and Toxoplasma Infections in Stray Cats from Iraq

    PubMed Central

    Switzer, Alexandra D.; McMillan-Cole, Audrey C.; Kasten, Rickie W.; Stuckey, Matthew J.; Kass, Philip H.; Chomel, Bruno B.

    2013-01-01

    Because of overpopulation, stray/feral cats were captured on military bases in Iraq as part of the US Army Zoonotic Disease Surveillance Program. Blood samples were collected from 207 cats, mainly in Baghdad but also in North and West Iraq, to determine the prevalence of Bartonella and Toxoplasma infections. Nine (4.3%) cats, all from Baghdad, were bacteremic with B. henselae type I. Seroprevalence was 30.4% for T. gondii, 15% for B. henselae, and 12.6% for B. clarridgeiae. Differences in Bartonella prevalence by location were statistically significant, because most of the seropositive cats were from Baghdad. There was no association between T. gondii seropositivity and either of the two Bartonella species surveyed. This report is the first report on the prevalence of Bartonella and T. gondii among stray cats in Iraq, which allows for better evaluation of the zoonotic risk potential to the Iraqi people and deployed military personnel by feral cat colonies. PMID:24062480

  12. Toxoplasma polymerase chain reaction on experimental blood samples.

    PubMed

    Joss, A W; Chatterton, J M; Evans, R; Ho-Yen, D O

    1993-01-01

    A two-stage polymerase chain reaction (PCR) assay employing oligonucleotide primers from the B1 gene of Toxoplasma gondii was developed and assessed for sensitivity and specificity. It was able to detect T. gondii DNA from as little as one parasite/sample in mock-infected rat or mouse leucocyte preparations. Parasitaemia was also identified in animals at five stages between 16 and 66 h after infection with the virulent RH strain, and at 12 stages between 2 and 38 days after infection with the cyst-forming Beverley strain. In the latter case, PCR was more sensitive than animal culture. No cross-reactions were observed in samples containing various opportunist pathogens which may also be found in the blood of immunocompromised patients.

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

    PubMed Central

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

    1999-01-01

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

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

    PubMed

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

    2007-03-01

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

  15. 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.

  16. Genetic and biochemical analysis of development in Toxoplasma gondii.

    PubMed Central

    Boothroyd, J C; Black, M; Bonnefoy, S; Hehl, A; Knoll, L J; Manger, I D; Ortega-Barria, E; Tomavo, S

    1997-01-01

    Toxoplasma gondii has recently come under intense study as a model for intracellular parasitism because it has a number of properties that facilitate experimental manipulation. Attention is now being turned towards understanding the developmental biology of this complex parasite. The differentiation between the two asexual stages, the rapidly growing tachyzoites and the more slowly dividing, encysted bradyzoites, is of particular interest. Progression from the former to the latter is influenced by the host's immune response. This paper describes current progress on a number of research fronts, all aimed at understanding the triggers that push the tachyzoite-bradyzoite equilibrium in one or other direction and the changes that occur in gene expression (and ultimately metabolism and function). Chief among the techniques used for these studies are genetics and molecular genetics. Recent progress in these areas is described. PMID:9355126

  17. Vertical transmission of Toxoplasma gondii in Australian marsupials

    PubMed Central

    Parameswaran, N.; O’Handley, R.M.; Grigg, M.E.; Wayne, A.; Thompson, R.C.A.

    2012-01-01

    SUMMARY To date, little is known about the dynamics of vertical transmission of Toxoplasma gondii in Australian marsupials. Studies in mice demonstrate that vertical transmission of T. gondii is common and that chronically infected mice can transmit T. gondii to successive generations. In this study, PCR and immunohistochemistry were used to detect T. gondii in chronically infected marsupial dams and their offspring. T. gondii was detected in the unfurred pouch young of 2 out of 10 chronically infected western grey kangaroos (Macropus fuliginosus) and in the unfurred pouch young of a brush-tailed bettong (Bettongia penicillata). Results of the study suggest vertical transmission of T. gondii can occur in chronically infected Australian marsupials. PMID:19549348

  18. [Toxoplasma gondii infection in pet dogs and owners in Hangzhou].

    PubMed

    Wang, Jia; Xu, Wei-min; Wang, Heng; Yang, Yang; Jin, Xing-yi; Huang, Yang-mei

    2014-12-01

    Sixty pet feeding families were obtained by random sampling in Hangzhou. The positive rate of IgG antibodies to Toxoplasma gondii in pet owners was 3.3% (4/120). The rate in males and females was 8.6% (3/35) and 1.2% (1/85) (χ2=4.207, P<0.05). The positive rate in pet dogs was 13.3% (8/60). The positive rate in dogs fed with a raw-meat diet (33.3%, 4/12) were significantly higher than that of others (4.2%, 2/48) (χ2=6.123, P<0.05).

  19. 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.

  20. 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.

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

    PubMed

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

    2016-12-01

    The obligate intracellular protozoan parasite Toxoplasma gondii actively invades virtually all warm-blooded nucleated cells. This process results in a non-fusogenic vacuole, inside which the parasites replicate continuously until egress signaling is triggered. In this work, we investigated the role of the large GTPase dynamin in the interaction of T. gondii with the host cell by using laser and electron microscopy during three key stages: invasion, development and egress. The detection of dynamin during invasion indicates the occurrence of endocytosis, while T. gondii egress appeared to be independent of dynamin participation. However, the presence of dynamin during T. gondii development suggests that this molecule plays undescribed roles in the tachyzoite's cell cycle. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  2. Serological survey of Toxoplasma gondii in captive Neotropical felids from Southern Brazil.

    PubMed

    Ullmann, Leila Sabrina; da Silva, Rodrigo Costa; de Moraes, Wanderlei; Cubas, Zalmir Silvino; dos Santos, Leonilda Correia; Hoffmann, Juliano Leônidas; Moreira, Nei; Guimaraes, Ana Marcia Sa; Montaño, Patrícia; Langoni, Helio; Biondo, Alexander Welker

    2010-08-27

    Toxoplasma gondii is the causative intracellular protozoan of toxoplasmosis in human being and animals. Members of the Felidae family are considered the single definitive host for the infection; both wild and domestic cats are able to excrete oocysts in the environment. Wild cats maintained in captivity may serve as source of infection for other clinically susceptible animals in the same environment. The aim of this study was to determine the frequency of T. gondii IgG antibodies in 57 neotropical felids (1 Leopardus geoffroyi; 3 Puma yagouaroundi; 17 Leopardus wiedii; 22 Leopardus tigrinus; and 14 Leopardus pardalis) kept at the Bela Vista Biological Sanctuary, Itaipu Binacional, Southern Brazil, by the modified agglutination test (MAT) using titer 16 as cut-off point. Seropositivity was observed in 38/57 (66.67%; 95% CI 53.66-77.51%) samples, with higher frequency in ocelots (71.43%). Wild-caught felids were three times more likely to be infected when compared to zoo-born animals (P=0.05) and age of wild-caught animals (P=0.6892; 95% CI=0.7528-1.66) was not significant as a risk factor for the infection, the same occurring with zoo-born animals (P=0.05; 95% CI=0.6267-24.052). These results suggest that, despite efforts to control T. gondii infection in zoo facilities, such as individual pens, hygiene monitoring, veterinary care and pre-frozen meat offered as food, non-domestic felids kept in captivity, particularly the wild-caught specimens, may be invariably exposed to infection due to other environmental sources.

  3. [Toxoplasma infections in early pregnancy: consequences and management].

    PubMed

    Wallon, M; Gaucherand, P; Al Kurdi, M; Peyron, F

    2002-09-01

    To assess the consequences for the fetus of maternal toxoplasma infection acquired during the first 8 weeks of gestation and to set guidelines on how to manage these maternal infections. Data were prospectively analyzed on 360 pregnancies followed-up in our department due to a toxoplasma infection during the 8 first weeks of pregnancy. Estimates of the risk of fetal infection were based on all cases, including those which could not be followed up until infection was ruled out or confirmed. Severity of infection was estimated based on ultrasound findings during pregnancy, neonatal and long-term postnatal clinical, neurological and ophthalmologic work up. Out of the 360 included women, 336 gave birth to a live born child: 7 (2%) were infected, 302 (90%) were free of infection and follow-up was insufficient to conclude about the 27 (8%) remaining infants. The estimated risk of fetal infection ranged between 2 and 10% based on live born children and between 3 and 14% when the 24 interrupted pregnancies were included. At their last clinical evaluation at 70 months of age, all 7 children, including the 2 who had inactive peripheral eye lesions and the one who had a unique intracranial calcification were free of any ophthalmologic or neurological impairment. Our study confirms that in the event of a maternal infection during the first 8 weeks of pregnancy the risk of fetal infection is low and results mainly in a spontaneous termination of pregnancy. Future parents should be assured that conversely to a common opinion, the prognosis of congenital toxoplasmosis in live-born children is good. For these early maternal infections as for those acquired later, we recommend immediate treatment with spiramycin, monthly ultrasound surveillance, amniocentesis and treatment with pyrimethamine and sulphamides if the PCR is positive. Abortion should be restricted to cases with ultrasound lesions

  4. Keratoconjunctivitis associated with Toxoplasma gondii in a dog.

    PubMed

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

    2009-01-01

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

  5. Toxoplasma gondii: Induction of egress by the potassium ionophore nigericin

    PubMed Central

    Fruth, Ingrid A.; Arrizabalaga, Gustavo

    2007-01-01

    The obligate intracellular parasite Toxoplasma gondii is an important pathogen of humans and animals. Some of the devastating consequences of toxoplasmosis are in part due to the lysis of the host cell during parasite egress. The process of egress is poorly understood and since it is asynchronous in tissue culture its study has been limited to those conditions that induce it, such as artificial permeabilization of the host cell and induction of calcium fluxes with ionophores. Given that permeabilization leads to egress by the activation of motility upon a drop in host cell potassium concentration, we investigated whether the ionophore nigericin, which selectively causes efflux of potassium from the cell without the need for permeabilization, would cause egress. Nigericin effectively causes intracellular parasites to exit their host cell within 30 min of treatment with the drug. Our results show that nigericin-induced egress depends on an efflux of potassium from the cell and requires phospholipase C function and parasite motility. This novel method of inducing and synchronizing egress mimics the effect of artificial permeabilization in all respects. Nevertheless, since the membrane remains intact during the treatment, in our nigericin-induced egress we are able to detect parasite-dependent permeabilization of the host cell, a known step in induced egress. In addition, consistent with the model that loss of host cell potassium leads to egress through the activation of intraparasitic calcium fluxes, a previously isolated Toxoplasma mutant lacking a sodium hydrogen exchanger and defective in responding to calcium fluxes does not undergo nigericin-induced egress. Thus, the discovery that nigericin induces egress presents a novel assay that allows for the genetic and biochemical analysis of the signaling mechanisms that lead to the induction of motility and egress. PMID:17618633

  6. Toxoplasma gondii: induction of egress by the potassium ionophore nigericin.

    PubMed

    Fruth, Ingrid A; Arrizabalaga, Gustavo

    2007-12-01

    The obligate intracellular parasite Toxoplasma gondii is an important pathogen of humans and animals. Some of the devastating consequences of toxoplasmosis are in part due to the lysis of the host cell during parasite egress. The process of egress is poorly understood and since it is asynchronous in tissue culture its study has been limited to those conditions that induce it, such as artificial permeabilisation of the host cell and induction of calcium fluxes with ionophores. Given that permeabilisation leads to egress by the activation of motility upon a drop in host cell potassium concentration, we investigated whether the ionophore nigericin, which selectively causes efflux of potassium from the cell without the need for permeabilisation, would cause egress. Nigericin effectively causes intracellular parasites to exit their host cell within 30 min of treatment with the drug. Our results show that nigericin-induced egress depends on an efflux of potassium from the cell and requires phospholipase C function and parasite motility. This novel method of inducing and synchronising egress mimics the effect of artificial permeabilisation in all respects. Nevertheless, since the membrane remains intact during the treatment, in our nigericin-induced egress we are able to detect parasite-dependent permeabilisation of the host cell, a known step in induced egress. In addition, consistent with the model that loss of host cell potassium leads to egress through the activation of intraparasitic calcium fluxes, a previously isolated Toxoplasma mutant lacking a sodium hydrogen exchanger and defective in responding to calcium fluxes does not undergo nigericin-induced egress. Thus, the discovery that nigericin induces egress presents a novel assay that allows for the genetic and biochemical analysis of the signalling mechanisms that lead to the induction of motility and egress.

  7. Mechanism of dexamethasone in the context of Toxoplasma gondii infection.

    PubMed

    Zhang, Jing; Qin, Xin; Zhu, Y U; Zhang, Shuang; Zhang, Xue-Wei; Lu, H E

    2017-09-01

    Toxoplasmosis is a serious zoonoses disease and opportunistic, and can be life-threatening. Dexamethasone (DEX) is widely used in the clinic for treatment of inflammatory and autoimmune diseases. However, long-term use of DEX is often easy to lead to acute toxoplasmosis in patients, and the potential molecular mechanism is still not very clear. The aims of this study were to investigate the effect of DEX on proliferation of Toxoplasma and its molecular mechanisms, and to establish the corresponding control measures. All the results showed that dexamethasone could enhance the proliferation of Toxoplasma gondii tachyzoites. After 72 h of DEX treatment, 566 (±7) tachyzoites were found in 100 host cells, while only 86 (±8) tachyzoites were counted from the non-treated control cells (P < 0·01). Gas chromatography (GC) analysis showed changes in level and composition of fatty acids in DEX-treated host cells, and T. gondii. Fish oil was added as a modulator of lipid metabolism in experimental mice. It was found that mice fed with fish oil did not develop the disease after infection with T. gondii, and the structure of fatty acids in plasma changed significantly. The metabolism of fatty acid in the parasites was limited, and the desaturase gene expression was downregulated. These results indicate that the molecular mechanism of dexamethasone to promote the proliferation of T. gondii may be that dexamethasone induces the change of fatty acids composition of tachyzoites and host cells. Therefore, we recommend supplementation of fatty acid in immunosuppressive and immunocompromised patients in order to inhibit toxoplasmosis.

  8. The Crystal Structure of Toxoplasma gondii Pyruvate Kinase 1

    SciTech Connect

    Bakszt, R.; Wernimont, A; Allali-Hassani, A; Mok, M; Hills, T; Hui, R; Pizarro, J

    2010-01-01

    Pyruvate kinase (PK), which catalyzes the final step in glycolysis converting phosphoenolpyruvate to pyruvate, is a central metabolic regulator in most organisms. Consequently PK represents an attractive therapeutic target in cancer and human pathogens, like Apicomplexans. The phylum Aplicomplexa, a group of exclusively parasitic organisms, includes the genera Plasmodium, Cryptosporidium and Toxoplasma, the etiological agents of malaria, cryptosporidiosis and toxoplasmosis respectively. Toxoplasma gondii infection causes a mild illness and is a very common infection affecting nearly one third of the world's population. We have determined the crystal structure of the PK1 enzyme from T. gondii, with the B domain in the open and closed conformations. We have also characterized its enzymatic activity and confirmed glucose-6-phosphate as its allosteric activator. This is the first description of a PK enzyme in a closed inactive conformation without any bound substrate. Comparison of the two tetrameric TgPK1 structures indicates a reorientation of the monomers with a concomitant change in the buried surface among adjacent monomers. The change in the buried surface was associated with significant B domain movements in one of the interacting monomers. We hypothesize that a loop in the interface between the A and B domains plays an important role linking the position of the B domain to the buried surface among monomers through two {alpha}-helices. The proposed model links the catalytic cycle of the enzyme with its domain movements and highlights the contribution of the interface between adjacent subunits. In addition, an unusual ordered conformation was observed in one of the allosteric binding domains and it is related to a specific apicomplexan insertion. The sequence and structural particularity would explain the atypical activation by a mono-phosphorylated sugar. The sum of peculiarities raises this enzyme as an emerging target for drug discovery.

  9. Posterior retroperitoneoscopic approach to the adrenal arteries.

    PubMed

    Lotti, Marco; Giulii Capponi, Michela

    2016-12-01

    Differently from transperitoneal adrenalectomy, with the posterior retroperitoneoscopic approach adrenal arteries are dissected first [1, 2]. Knowledge of their position is pivotal as they are covered by peri-adrenal fat [3, 4]. Four posterior retroperitoneoscopic adrenalectomies were selected, in which adrenal arteries are dissected to show their path and how they can be localized among peri-adrenal fat. A video is presented herein, which focuses on surgical anatomy of adrenal arteries when approached during a posterior retroperitoneoscopic adrenalectomy. Details about relative positions between adrenal arteries and adjacent structures are considered and shown during their dissection. The posterior retroperitoneoscopic approach offers a direct view of adrenal arteries and allows for their exposure and safe division in the early steps of adrenalectomy.

  10. Posterior cruciate ligament (PCL) injury - aftercare

    MedlinePlus

    Adib F, Curtis C, Bienkowski P Micheli LJ. Posterior cruciate ligament sprain. In: Frontera WR, Silver JK, Rizzo TD Jr, eds. Essentials of Physical Medicine and Rehabilitation: Musculoskeletal Disorders, ...

  11. Posterior Hip Pain in an Athletic Population

    PubMed Central

    Frank, Rachel M.; Slabaugh, Mark A.; Grumet, Robert C.; Virkus, Walter W.; Bush-Joseph, Charles A.; Nho, Shane J.

    2010-01-01

    Context: Posterior hip pain is a relatively uncommon but increasingly recognized complaint in the orthopaedic community. Patient complaints and presentations are often vague or nonspecific, making diagnosis and subsequent treatment decisions difficult. The purposes of this article are to review the anatomy and pathophysiology related to posterior hip pain in the athletic patient population. Evidence Acquisition: Data were collected through a thorough review of the literature via a MEDLINE search of all relevant articles between 1980 and 2010. Results: Many patients who complain of posterior hip pain actually have pain referred from another part of the body—notably, the lumbar spine or sacroiliac joint. Treatment options for posterior hip pain are typically nonoperative; however, surgery is warranted in some cases. Conclusions: Recent advancements in the understanding of hip anatomy, pathophysiology, and treatment options have enabled physicians to better diagnosis athletic hip injuries and select patients for appropriate treatment. PMID:23015944

  12. Host lipid droplets: An important source of lipids salvaged by the intracellular parasite Toxoplasma gondii

    PubMed Central

    Romano, Julia D.

    2017-01-01

    Toxoplasma is an obligate intracellular parasite that replicates in mammalian cells within a parasitophorous vacuole (PV) that does not fuse with any host organelles. One mechanism developed by the parasite for nutrient acquisition is the attraction of host organelles to the PV. Here, we examined the exploitation of host lipid droplets (LD), ubiquitous fat storage organelles, by Toxoplasma. We show that Toxoplasma replication is reduced in host cells that are depleted of LD, or impaired in TAG lipolysis or fatty acid catabolism. In infected cells, the number of host LD and the expression of host LD-associated genes (ADRP, DGAT2), progressively increase until the onset of parasite replication. Throughout infection, the PV are surrounded by host LD. Toxoplasma is capable of accessing lipids stored in host LD and incorporates these lipids into its own membranes and LD. Exogenous addition of oleic acid stimulates LD biogenesis in the host cell and results in the overaccumulation of neutral lipids in very large LD inside the parasite. To access LD-derived lipids, Toxoplasma intercepts and internalizes within the PV host LD, some of which remaining associated with Rab7, which become wrapped by an intravacuolar network of membranes (IVN). Mutant parasites impaired in IVN formation display diminished capacity of lipid uptake from host LD. Moreover, parasites lacking an IVN-localized phospholipase A2 are less proficient in salvaging lipids from host LD in the PV, suggesting a major contribution of the IVN for host LD processing in the PV and, thus lipid content release. Interestingly, gavage of parasites with lipids unveils, for the first time, the presence in Toxoplasma of endocytic-like structures containing lipidic material originating from the PV lumen. This study highlights the reliance of Toxoplasma on host LD for its intracellular development and the parasite’s capability in scavenging neutral lipids from host LD. PMID:28570716

  13. MicroRNA-132 dysregulation in Toxoplasma gondii infection has implications for dopamine signaling pathway

    PubMed Central

    Xiao, Jianchun; Li, Ye; Prandovszky, Emese; Karuppagounder, Senthilkumar S.; Talbot, C. Conover; Dawson, Valina L.; Dawson, Ted M.; Yolken, Robert H.

    2014-01-01

    Congenital toxoplasmosis and toxoplasmic encephalitis can be associated with severe neuropsychiatric symptoms. However, which host cell processes are regulated and how Toxoplasma gondii affects these changes remain unclear. MicroRNAs (miRNAs) are small noncoding RNA sequences critical to neurodevelopment and adult neuronal processes by coordinating the activity of multiple genes within biological networks. We examined the expression of over 1000 miRNAs in human neuroepithelioma cells in response to infection with Toxoplasma. MiR-132, a cyclic AMP-responsive element binding (CREB)-regulated miRNA, was the only miRNA that was substantially upregulated by all three prototype Toxoplasma strains. The increased expression of miR-132 was also documented in mice following infection with Toxoplasma. To identify cellular pathways regulated by miR-132, we performed target prediction followed by pathway enrichment analysis in the transcriptome of Toxoplasma-infected mice. This led us to identify 20 genes and dopamine receptor signaling was their strongest associated pathway. We then examined myriad aspects of the dopamine pathway in the striatum of Toxoplasma infected mice 5 days after infection. Here we report decreased expression of D1-like dopamine receptors (DRD1, DRD5), metabolizing enzyme (MAOA) and intracellular proteins associated with the transduction of dopamine-mediated signaling (DARPP-32 phosphorylation at Thr34 and Ser97). Increased concentrations of dopamine and its metabolites, serotonin and 5-hydroxyindoleacetic acid were documented by HPLC analysis; however, the metabolism of dopamine was decreased and serotonin metabolism was unchanged. Our data show that miR-132 is upregulated following infection with Toxoplasma and is associated with changes in dopamine receptor signaling. Our findings provide a possible mechanism for how the parasite contributes to the neuropathology of infection. PMID:24657774

  14. Toxoplasma prevalence among pregnant women in Norway: a cross-sectional study.

    PubMed

    Findal, Gry; Barlinn, Regine; Sandven, Irene; Stray-Pedersen, Babill; Nordbø, Svein A; Samdal, Helvi H; Vainio, Kirsti; Dudman, Susanne G; Jenum, Pål A

    2015-04-01

    Infection by Toxoplasma gondii may lead to complications in the foetus if the mother suffers from primary infection during pregnancy. Previously infected women have produced toxoplasma-specific IgG antibodies. The most recent study on prevalence of toxoplasma IgG in the Norwegian pregnant population was conducted 20 years ago. The present study is part of a research programme initiated by the Norwegian Institute of Public Health. We aimed to update the knowledge regarding the prevalence of toxoplasma IgG among pregnant women in Norway. In this cross-sectional study, sera from 1922 pregnant women in Buskerud (992) and Sør-Trøndelag counties (930) in Norway were collected consecutively. The presence of toxoplasma IgG was identified by values ≥8 IU/mL using an ELISA test. The overall prevalence of toxoplasma IgG seropositivity was 9.3% (95% CI 8.1-10.7); Sør-Trøndelag 10.4% (95% CI 8.6-12.6) and Buskerud 8.3% (95% CI 6.7-10.2). There was no difference between the counties (p = 0.13), and the result did not differ from prevalences found in 1974 (12.1%) and 1994 (10.7%). We found a higher prevalence among women ≥40 years (OR 2.65, 95% CI 1.30-5.42). The prevalence of toxoplasma IgG among pregnant women in Norway is low and has been stable during the last decades.

  15. [Posterior cortical atrophy (Benson-syndrome)].

    PubMed

    Rózsa, Anikó; Szilvássy, Ildikó; Kovács, Krisztina; Boór, Krisztina; Gács, Gyula

    2010-01-30

    We present the characteristics of posterior cortical atrophy--a very rare cortical dementia--in a 69 year old woman's case. Our patient's symptoms began with a visual problem which was initially explained by ophthalmological disorder. After neurological exam visual agnosia was diagnosed apart from other cognitive disorder (alexia without agraphia, acalculia, prosopagnosia, constructional disorder, clock-time recognition disorder, dressing apraxia, visuospatial disorientation). The brain MRI showed bilateral asymmetric parieto-occipital atrophy which is characteristic of posterior cortical atrophy.

  16. Gibbs Sampling for Marginal Posterior Expectations

    DTIC Science & Technology

    1991-11-19

    Achcar and Smith (1989) shows that performance of the Laplace method is often very sensitive to parametrization. Morris (1988) offers expansions based on...Berkeley Symp. 1, 453-468. Lindley, D.V. (1980). "Approximate Bayesian Methods" in Bayesian Statistics, J.M. Bernardo, M.H. DeGroot , D.V. Lindley...A.F.M. Smith, University Press, Valencia, Spain. Morris , C. "Approximating Posterior Distributions and Posterior Moments" In: Bayesian Statistics 3, J.M

  17. Posterior Wnts Have Distinct Roles in Specification and Patterning of the Planarian Posterior Region.

    PubMed

    Sureda-Gómez, Miquel; Pascual-Carreras, Eudald; Adell, Teresa

    2015-11-05

    The wnt signaling pathway is an intercellular communication mechanism essential in cell-fate specification, tissue patterning and regional-identity specification. A βcatenin-dependent signal specifies the AP (Anteroposterior) axis of planarians, both during regeneration of new tissues and during normal homeostasis. Accordingly, four wnts (posterior wnts) are expressed in a nested manner in central and posterior regions of planarians. We have analyzed the specific role of each posterior wnt and the possible cooperation between them in specifying and patterning planarian central and posterior regions. We show that each posterior wnt exerts a distinct role during re-specification and maintenance of the central and posterior planarian regions, and that the integration of the different wnt signals (βcatenin dependent and independent) underlies the patterning of the AP axis from the central region to the tip of the tail. Based on these findings and data from the literature, we propose a model for patterning the planarian AP axis.

  18. Vertigo due to posterior circulation stroke.

    PubMed

    Kim, Ji Soo; Lee, Hyung

    2013-07-01

    Stroke in the distribution of the posterior circulation may present as acute onset spontaneous vertigo and imbalance. Although vertigo due to posterior circulation stroke is usually associated with other neurologic symptoms or signs, small infarcts in the cerebellum or brainstem can present with vertigo without other localizing symptoms. Approximately 17% of patients with isolated posterior inferior cerebellar artery territory infarction presented with isolated vertigo, nystagmus, and postural unsteadiness. A head impulse test can differentiate acute isolated vertigo associated with cerebellar stroke from more benign disorders involving the inner ear. Sometimes acute isolated audiovestibular loss can be the initial symptom of impending posterior circulation ischemic stroke (particularly within the territory of the anterior inferior cerebellar artery). In this case, evaluation of isolated audiovestibular loss may prevent the progression of acute vertigo and hearing loss into more widespread areas of infarction in the posterior circulation. In this article, the clinical syndromes and signs of acute vestibular syndrome due to posterior circulation stroke involving the brainstem and cerebellum are summarized.

  19. Posterior urethral polyp with type I posterior urethral valves: a rare association in a neonate.

    PubMed

    Kesan, Krushnakumar V; Gupta, Rahul Kumar; Kothari, Paras; Gupta, Abhaya; Mudkhedkar, Kedar; Kamble, Ravikiran; Dikshit, K Vishesh

    2014-06-01

    Urethral polyp is a rare cause of bladder outlet obstruction, voiding dysfunction, and hematuria in the pediatric age group. Urethral polyps are rarely associated with other congenital urinary tract anomalies. In this study, we report a case of solitary posterior urethral polyp with type I posterior urethral valve in a 7-day-old neonate presented with urinary retention and deranged renal function. The polyp was diagnosed on cystoscopy. Transurethral resection of the polyp with posterior urethral valve fulguration was performed. Pathologic assessment revealed a fibroepithelial lesion, which was consistent with congenital posterior urethral polyp.

  20. Arthroscopic classification of posterior labrum glenoid insertion.

    PubMed

    Nourissat, G; Radier, C; Aim, F; Lacoste, S

    2014-04-01

    We performed a prospective arthroscopic study to explore the variability of the posterior labrum glenoid insertion. We aimed to classify the insertions and to explore whether these insertions can be identified by pre-operative arthro-CT scan. From January to December 2011, 86 patients were prospectively included in the current study. During arthroscopy, anterior labrum was evaluated and posterior labrum was assessed in 3 different locations: superior, medial, and inferior. For each segment, the labrum was considered normally inserted (directly to the glenoid cartilage), medialized (inserted at the posterior part of the glenoid bone, without direct contact with the cartilage), torn (macroscopic degenerative changes, tears, fragments) or absent (agenesis). Imaging was analyzed segment by segment by an experienced osteoarticular radiologist, using the same classification. Four types of posterior labrum insertions were identified. Type 1, 60% of the cases, corresponded to a posterior labrum totally inserted in the glenoid, with direct contact with the cartilage. Type 2, 20% of the cases, represented medialized insertion of the superior segment. Type 3, 15% of the cases, represented an associated medialization of the superior and medial segment of the posterior labrum. Type 4 is a medialized insertion of the all-posterior labrum. Fifty-six shoulders were used for arthro-CT and arthroscopy correlation: for the superior segment (n=22/56), the sensitivity of arthro-CT to identify an abnormal insertion when the labrum is medialized was 68.18%, specificity 70.59%, positive predictive value (PPV) 60%, and negative predictive value (NPV) 77.42%. For the medial segment (n=16/56), the sensitivity of arthro-CT to identify an abnormal insertion when the labrum is medialized was 81.25%, specificity 57.50%, PPV 43.33% and NPV 88.46%. For the inferior segment (n=5/56), the sensitivity was 100%, specificity 47.60%, PPV 15.63% and NPV 100%. The current study points out the high

  1. The Effect of Fluphenazine and Thioridazine on Toxoplasma gondii In Vivo

    PubMed Central

    SARAEI, Mehrzad; GHADERI, Yosef; MOSAVI, Tahereh; SHAHNAZI, Mojtaba; NASSIRI-ASL, Marjan; JAHANIHASHEMI, Hassan

    2016-01-01

    Background: Toxoplasma gondii is the most common parasite causing latent cerebral infections in human. It has been shown that some anti-psychotic drugs are able to inhibit the proliferation of the parasite in in vitro study. There is very limited data regarding the inhibitory effect of anti-psychotics on Toxoplasma in in vivo. In this study, we evaluated anti-Toxoplasma activity of fluphenazine and thioridazine drugs on T. gondii in mice. Methods: Mice were divided into six groups: Control, sesame as vehicle, thioridazine 10 mg/kg, thioridazine 20 mg/kg, fluphenazine 0.06 mg/kg and fluphenazine 0.6 mg/kg. They were inoculated intraperitoneally with brain suspension containing tissue cysts of T. gondii Tehran strain. Two months after inoculation, the number of cysts in crushed smears of mice brain were counted microscopically and considered as an indicator of anti-Toxoplasma activity. This work has conducted in Qazvin, central Iran, 2014. Results: Our study showed that fluphenazine and thioridazine could not significantly inhibit the brain cystogenesis of T. gondii in mice. However, the number of brain cysts was less at higher dose compared to lower doses for both drugs. Conclusion: Further studies need to clear the mechanism of different structure of anti-psychotic drugs on activity of Toxoplasma. PMID:28096857

  2. 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.

  3. A possible relationship between Toxoplasma gondii and schizophrenia: A seroprevalence study.

    PubMed

    Dogruman-Al, Funda; Aslan, Selcuk; Yalcin, Safak; Kustimur, Semra; Turk, Songul

    2009-01-01

    Objective. Schizophrenia is a pervasive neuropsychiatric disease of uncertain etiology. We aimed to investigate a possible association between Toxoplasma gondii infection and schizophrenia in this study. Method. We selected individuals with schizophrenia (n=88) and tested them with commercially available enzyme-linked immunosorbent assay (ELISA) for anti-Toxoplasma IgG and IgM antibodies and compared these seropositivity rate to those of controls without psychiatric disease (n=88). Results. The rate of IgG antibody in the schizophrenia patients (47.7%) was higher than the control groups (20.4%) (P<0.001). We did not find any anti-Toxoplasma IgM seropositivity in both schizophrenia patients and control group. In schizophrenic patients with and without anti-Toxoplasma IgG groups statistical analysis did not reveal any correlation between demographic variables and Toxoplasma infection. Conclusion. Our findings supported previous studies indicate that T.gondii may play a role in etiopathogenesis in some cases of schizophrenia.

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

    PubMed Central

    Reiff, Sarah B.; Vaishnava, Shipra

    2012-01-01

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

  5. Toxoplasma gondii seropositivity and cognitive functions in school-aged children.

    PubMed

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

    2015-08-01

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

  6. Base excision repair apurinic/apyrimidinic endonucleases in apicomplexan parasite Toxoplasma gondii

    PubMed Central

    Onyango, David O.; Naguleswaran, Arunasalam; Delaplane, Sarah; Reed, April; Kelley, Mark R.; Georgiadis, Millie M.; Sullivan, William J.

    2011-01-01

    DNA repair is essential for cell viability and proliferation. In addition to reactive oxygen produced as a byproduct of their own metabolism, intracellular parasites also have to manage oxidative stress generated as a defense mechanism by the host. The spontaneous loss of DNA bases due to hydrolysis and oxidative DNA damage in intracellular parasites is great, but little is known about the type of DNA repair machineries that exist in these early-branching eukaryotes. However, it is clear processes similar to DNA base excision repair (BER) must exist to rectify spontaneous and host-mediated damage in Toxoplasma gondii. Here we report that Toxoplasma gondii, an opportunistic protozoan pathogen, possesses two apurinic/apyrimidinic (AP) endonucleases that function in DNA BER. We characterize the enzymatic activities of Toxoplasma exonuclease III (ExoIII, or Ape1) and endonuclease IV (EndoIV, or Apn1), designated TgAPE and TgAPN, respectively. Over-expression of TgAPN in Toxoplasma conferred protection from DNA damage, and viable knockouts of TgAPN were not obtainable. We generated an inducible TgAPN knockdown mutant using a ligand-controlled destabilization domain to establish that TgAPN is critical for Toxoplasma to recover from DNA damage. The importance of TgAPN and the fact that humans lack any observable APN family activity highlights TgAPN as a promising candidate for drug development to treat toxoplasmosis. PMID:21353648

  7. Residual infection of 15 toxoplasma strains in the brain of rats fed cysts.

    PubMed

    Freyre, A; Falcón, J; Correa, O; Mendez, J; González, M; Venzal, J M

    2001-11-01

    Thirty-seven groups of 4-32 Wistar rats were 2-10(3) cysts of 15 Toxoplasma strains. After 2 months, the rats were euthanized and their brains screened for Toxoplasma cysts and bioassayed in mice if negative. The brains of 323 of 411 rats (78.6%) were found to be infected 2 months after inoculation with Toxoplasma cysts. Two hundred cysts were necessary to infect nearly 90% of the rats. With lower doses, only 60% of the rats had residual brain infection. Brain cysts were formed only in 146 of 411 rats (35.5%). The numbers of cysts formed were in the order of tens to hundreds, only occasionally one or two thousands. The mean percentage of rats with brain cysts, and the number of cysts formed in rat brains by different inocula, increased with higher doses of cysts and then declined. This pattern is difficult to explain and similar results regarding the number of cysts formed have been published. In relation to the mean percentage of rats infected, there appears to be a plateau in infection with the higher inocula. Neither the number of rats with cysts in their brains nor the numbers of cysts formed were dependent on the Toxoplasma strain used, with the exception of one strain. Instead, individual variations were marked, and are presumably related to variations in the individual genetic resistance to Toxoplasma infection in the rat. The information gathered is considered a preliminary step for a rat model of immunity against acquired toxoplasmosis.

  8. Effects of (+)-usnic acid and (+)-usnic acid-liposome on Toxoplasma gondii.

    PubMed

    Si, Kaiwei; Wei, Linlin; Yu, Xiaozhuo; Wu, Feng; Li, Xiaoqi; Li, Chen; Cheng, Yanbin

    2016-07-01

    Toxoplasma gondii pathogen is a threat to human health that results in economic burden. Unfortunately, there are very few high-efficiency and low-toxicity drugs for toxoplasmosis in the clinic. (+)-Usnic acid derived from lichen species has been reported to have anti-inflammatory, antibacterial, anti-parasitology, and even anti-cancer activities. Herein, the systematic effect of (+)-usnic acid and (+)-usnic acid-liposome on toxoplasma were studied in vitro and in vivo. The viability of toxoplasma tachyzoite was assayed with trypan blue and Giemsa staining; while the invasive capability of tachyzoite to cardiofibroblasts was detected using Giemsa staining. The survival time of mice and the changes in tachyzoite ultrastructure were studied in vivo. The results showed that (+)-usnic acid inhibited the viability of tachyzoite; pretreatment with (+)-usnic acid significantly decreased the invasion of tachyzoite to cardiofibroblasts in vitro; (+)-usnic acid and (+)-usnic acid-liposome extensively prolonged the survival time of mice about 90.9% and 117%, respectively; and improved the ultrastructural changes of tachyzoite, especially in dense granules, rhoptries, endoplasmic reticulum, mitochondria and other membrane organelles. In summary, these results demonstrate that (+)-usnic acid and (+)-usnic acid-liposome with low toxicity have an inhibitory effect on the viability of toxoplasma tachyzoite, and mainly destructed membrane organelles which are connected with the virulence of toxoplasma. These findings provide the basis for further study and development of usnic acid as a potential agent for treating toxoplasmosis.

  9. Optimization of the cryopreservation of biological resources, Toxoplasma gondii tachyzoites, using flow cytometry.

    PubMed

    Mzabi, Alexandre; Escotte-Binet, Sandie; Le Naour, Richard; Ortis, Naïma; Audonnet, Sandra; Dardé, Marie-Laure; Aubert, Dominique; Villena, Isabelle

    2015-12-01

    The conservation of Toxoplasma gondii strains isolated from humans and animals is essential for conducting studies on Toxoplasma. Conservation is the main function of the French Biological Toxoplasma Resource Centre (BRC Toxoplasma, France, http://www.toxocrb.com/). In this study, we have determined the suitability of a standard cryopreservation methodology for different Toxoplasma strains using the viability of tachyzoites assayed by flow cytometry with dual fluorescent labelling (calcein acetoxymethyl ester and propidium iodide) of tachyzoites. This method provides a comparative quantitative assessment of viability after thawing. The results helped to define and refine quality criteria before tachyzoite cryopreservation and optimization of the cryopreservation parameters. The optimized cryopreservation method uses a volume of 1.0 mL containing 8 × 10(6) tachyzoites, in Iscove's Modified Dulbecco's Medium (IMDM) containing 10% foetal calf serum (FCS). The cryoprotectant additive is 10% v/v Me2SO without incubation. A cooling rate of ∼1 °C/min to -80 °C followed, after 48 h, by storage in liquid nitrogen. Thawing was performed using a 37 °C water bath that produced a warming rate of ∼100 °C/min, and samples were then diluted 1:5 in IMDM with 5% FCS, and centrifuged and resuspended for viability assessment.

  10. Oxidative stress generated during monensin treatment contributes to altered Toxoplasma gondii mitochondrial function.

    PubMed

    Charvat, Robert A; Arrizabalaga, Gustavo

    2016-03-15

    The ionophore monensin displays potent activities against several coccidian parasites of veterinary and medical importance including the opportunistic pathogen of humans, Toxoplasma gondii. While monensin is used widely in animals, toxicity impedes its use in humans. Nonetheless, given its potency, understanding its mode of action would reveal vulnerable aspects of the parasite that can be exploited for drug development. We previously established that monensin induces Toxoplasma to undergo cell cycle arrest and an autophagy-like cell death. Interestingly, these effects are dependent on the mitochondrion-localized TgMSH-1 protein, suggesting that monensin disrupts mitochondrial function. We demonstrate that monensin treatment results in decreased mitochondrial membrane potential and altered morphology. These effects are mitigated by the antioxidant compound N-acetyl-cysteine suggesting that monensin causes an oxidative stress, which was indeed the case based on direct detection of reactive oxygen species. Moreover, over-expression of the antioxidant proteins glutaredoxin and peroxiredoxin 2 protect Toxoplasma from the deleterious effects of monensin. Thus, our studies show that the effects of monensin on Toxoplasma are due to a disruption of mitochondrial function caused by the induction of an oxidative stress and implicate parasite redox biology as a viable target for the development of drugs against Toxoplasma and related pathogenic parasites.

  11. Oxidative stress generated during monensin treatment contributes to altered Toxoplasma gondii mitochondrial function

    PubMed Central

    Charvat, Robert A.; Arrizabalaga, Gustavo

    2016-01-01

    The ionophore monensin displays potent activities against several coccidian parasites of veterinary and medical importance including the opportunistic pathogen of humans, Toxoplasma gondii. While monensin is used widely in animals, toxicity impedes its use in humans. Nonetheless, given its potency, understanding its mode of action would reveal vulnerable aspects of the parasite that can be exploited for drug development. We previously established that monensin induces Toxoplasma to undergo cell cycle arrest and an autophagy-like cell death. Interestingly, these effects are dependent on the mitochondrion-localized TgMSH-1 protein, suggesting that monensin disrupts mitochondrial function. We demonstrate that monensin treatment results in decreased mitochondrial membrane potential and altered morphology. These effects are mitigated by the antioxidant compound N-acetyl-cysteine suggesting that monensin causes an oxidative stress, which was indeed the case based on direct detection of reactive oxygen species. Moreover, over-expression of the antioxidant proteins glutaredoxin and peroxiredoxin 2 protect Toxoplasma from the deleterious effects of monensin. Thus, our studies show that the effects of monensin on Toxoplasma are due to a disruption of mitochondrial function caused by the induction of an oxidative stress and implicate parasite redox biology as a viable target for the development of drugs against Toxoplasma and related pathogenic parasites. PMID:26976749

  12. 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

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

    PubMed Central

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

    2012-01-01

    Purpose: Toxoplasma gondii is a widespread protozoan parasite that infects a broad range of warm blooded animals as well as humans. The present study was investigated to evaluate the effects of allium cepa on renal failur in male rats which experimentally infected by Toxoplasma gondii, RH strain. Methods: Wistar male rat (n=40) were allocated into four groups, group one that received tachyzoites of T. gondii (ip) (n=10), group two that received tachyzoites of T. gondii (ip), plus fresh onion juice by gavages method (n=10), group three received just fresh onion juice by gavages method (n=10) and control group (n=10) that received nothing. Animals were kept in standard condition. In 30 day after inducing Toxoplasma infection, 5cc blood was collected for serum protein and TAC levels. Kidney tissues of Rat in whole groups were removed and prepared for apopetosis analysis. Results: Serum protein and kidneys weights were significantly decreased in groups that were infected with T. gondii, in comparison to control and onions groups. Kidneys Apopetosis in toxoplasma group significantly increased in comparison to control group (P<0.05).level of TAC was significantly increased in groups that received onio juice (P<0.05). Conclusion: This study showed that T. gondii have significantly effect on serum protein and TAC, apopetosis and fresh onion juice returned and treated this harmful effect, so it is suggested that eating of onion is useful in toxoplasma infection. PMID:24312764

  14. Transnasal endoscopic repair of posterior table fractures.

    PubMed

    Chaaban, Mohamad R; Conger, Bryant; Riley, Kristen O; Woodworth, Bradford A

    2012-12-01

    Conventional treatment of frontal sinus posterior table fractures has included osteoplastic flap or cranialization procedures despite considerable advances in endoscopic technique and experience. The objective of the current study was to evaluate outcomes of frontal sinus fractures involving the posterior table managed using endoscopic approaches. Prospective cohort. Tertiary care, academic university hospital. Prospective evaluation of patients with posterior table fractures was performed. Data were collected regarding demographics, etiology, technique, operative site, length involving the posterior table, size of the skull base defect, complications, and clinical follow-up. Thirteen patients (average age 37 years) with posterior table fractures were treated using endoscopic techniques from 2008 to 2012. Mean follow-up time was 68 weeks (range, 2-206 weeks). Patients were primarily managed using Draf IIb frontal sinusotomies with 1 individual requiring a concomitant trephine. A Draf III procedure was performed in 1 patient. Average fracture defect (length vs width) was 13 × 4.5 mm, and average length involving the posterior table was 9.7 mm (1-30 mm). Skull base defects were covered with a septal flap and/or free tissue grafts. Although 1 individual required a revision frontal sinusotomy and follow-up was short in several patients, all sinuses remained patent on last clinical examination. Management of frontal sinus posterior table fractures using minimally invasive endoscopic techniques provides excellent outcomes in selected cases. Fractures of up to 30 mm in length were adequately managed in this series and indicate this approach can be a viable alternative in the treatment of these fractures.

  15. Is posterior delamination in arthroscopic rotator cuff repair hidden to the posterior viewing portal?

    PubMed

    Han, Yung; Shin, Jin-Hyup; Seok, Chang-Woo; Lee, Chang-Hyun; Kim, Seung-Ho

    2013-11-01

    The purposes of this study were (1) to examine whether posterior delamination is hidden to the most commonly used posterior viewing portal compared with differential rotator cuff portals and (2) to observe posterior delamination patterns so that a treatment-based classification system may be proposed. One-hundred thirty consecutive patients undergoing arthroscopic rotator cuff repair by 4 different surgeons were evaluated for the presence of posterior delamination viewable through the posterior, posterolateral, and lateral portals. Randomized arthroscopic pictures were viewed by 2 independent blinded observers, and the Fleiss κ was used to assess inter-reliability agreement. In addition, patterns of posterior delamination and surgical treatment were assessed. The incidence of posterior delamination was 88%. Only 11% of cases were visualized through the posterior portal, whereas 70% and 100% were visualized through the posterolateral and lateral portals, respectively. The Fleiss κ was 0.78 (95% confidence interval, 0.73 to 0.83), indicating substantial agreement. Three general patterns of posterior delamination with specific surgical repair strategies were identified and subclassified into 5 types: type A1, full-thickness tears with extensive posterior delamination separating the rotator cuff into 2 layers and sometimes with dissociation of the rotator cable; type A2, bursal-sided partial-thickness tears with posterior delamination; type B1, delamination with an L-shaped bursal layer tear and crescent-shaped articular layer tear; type B2, a partial-thickness articular-sided tear with extensive posterior delamination; and type C, extensive degeneration with multiple longitudinal bursal-sided tears. The incidence of posterior delamination is extremely high, and most of these lesions are missed if one is viewing from just the posterior portal. Differential rotator cuff portals are needed to appreciate and treat posterior delamination. Patterns of delamination can be

  16. Toxoplasma gondii infection in workers occupationally exposed to unwashed raw fruits and vegetables: a case control seroprevalence study

    PubMed Central

    2011-01-01

    Background Through a case control seroprevalence study, we sought to determine the association of Toxoplasma gondii infection with occupational exposure to unwashed raw fruits and vegetables. Methods Subjects, numbering 200, who worked growing or selling fruits and vegetables, and 400 control subjects matched by age, gender, and residence were examined by enzyme immunoassays for the presence of anti-Toxoplasma IgG and IgM antibodies. Socio-demographic, clinical, and behavioral characteristics from the study subjects were obtained. Results Of the 200 fruit and vegetable workers, 15 (7.5%) of whom, and 31 (7.8%) of the 400 controls were positive for anti-Toxoplasma IgG antibodies (P = 0.96). Anti-Toxoplasma IgM antibodies were found in 2 (1%) of the fruit workers and in 11 (2.8%) of the control subjects (P = 0.23). Seroprevalence of Toxoplasma antibodies increased with age (P = 0.0004). In addition, seropositivity to Toxoplasma was associated with ill status (P = 0.04), chronic tonsillitis (P = 0.03), and reflex impairment (P = 0.03). Multivariate analysis showed that Toxoplasma infection was associated with consumption of raw meat (OR = 5.77; 95% CI: 1.15-28.79; P = 0.03), unwashed raw fruits (OR = 2.50; 95% CI: 1.11-5.63; P = 0.02), and living in a house with soil floors (OR = 3.10; 95% CI: 1.22-7.88; P = 0.01), whereas Toxoplasma infection was negatively associated with traveling abroad (OR = 0.28; 95% CI: 0.12-0.67; P = 0.005). Conclusions This is the first report of seroprevalence and contributing factors for Toxoplasma infection in workers occupationally exposed to unwashed raw fruits and vegetables, and the results may help in the design of optimal preventive measures against Toxoplasma infection especially in female workers at reproductive age. PMID:22177118

  17. Bayesian estimation of diagnostic accuracy of a new bead-based antibody detection test to reveal Toxoplasma gondii infections in pig populations.

    PubMed

    Bokken, Gertie C A M; Portengen, Lützen; Cornelissen, Jan B W J; Bergwerff, Aldert A; van Knapen, Frans

    2015-01-15

    The success of a Toxoplasma gondii surveillance program in European pig production systems depends partly on the quality of the test to detect infection in the population. The test accuracy of a recently developed serological bead-based assay (BBA) was investigated earlier using sera from experimentally infected animals. In this study, the accuracy of the BBA was determined by the use of sera from animals from two field subpopulations. As no T. gondii infection information of these animals was available, test accuracy was determined through a Bayesian approach allowing for conditional dependency between BBA and an ELISA test. The priors for prevalence were based on available information from literature, whereas for specificity vague non-informative priors were used. Priors for sensitivity were based either on available information or specified as non-informative. Posterior estimates for BBA sensitivity and specificity were (mode) 0.855 (Bayesian 95% credibility interval (bCI) 0.702-0.960) and 0.913 (bCI 0.893-0.931), respectively. Comparing the results of BBA and ELISA, sensitivity was higher for the BBA while specificity was higher for ELISA. Alternative priors for the sensitivity affected posterior estimates for sensitivity of both BBA and ELISA, but not for specificity. Because the difference in prevalence between the two subpopulations is small, and the number of infected animals is small as well, the precision of the posterior estimates for sensitivity may be less accurate in comparison to the estimates for specificity. The estimated value for specificity of BBA is at least optimally defined for testing pigs from conventional and organic Dutch farms.

  18. Posterior cruciate ligament removal contributes to abnormal knee motion during posterior stabilized total knee arthroplasty.

    PubMed

    Cromie, Melinda J; Siston, Robert A; Giori, Nicholas J; Delp, Scott L

    2008-11-01

    Abnormal anterior translation of the femur on the tibia has been observed in mid flexion (20-60 degrees ) following posterior stabilized total knee arthroplasty. The underlying biomechanical causes of this abnormal motion remain unknown. The purpose of this study was to isolate the effects of posterior cruciate ligament removal on knee motion after total knee arthroplasty. We posed two questions: Does removing the posterior cruciate ligament introduce abnormal anterior femoral translation? Does implanting a posterior stabilized prosthesis change the kinematics from the cruciate deficient case? Using a navigation system, we measured passive knee kinematics of ten male osteoarthritic patients during surgery after initial exposure, after removing the anterior cruciate ligament, after removing the posterior cruciate ligament, and after implanting the prosthesis. Passively flexing and extending the knee, we calculated anterior femoral translation and the flexion angle at which femoral rollback began. Removing the posterior cruciate ligament doubled anterior translation (from 5.1 +/- 4.3 mm to 10.4 +/- 5.1 mm) and increased the flexion angle at which femoral rollback began (from 31.2 +/- 9.6 degrees to 49.3 +/- 7.3 degrees). Implanting the prosthesis increased the amount of anterior translation (to 16.1 +/- 4.4 mm), and did not change the flexion angle at which femoral rollback began. Abnormal anterior translation was observed in low and mid flexion (0-60 degrees) after removing the posterior cruciate ligament, and normal motion was not restored by the posterior stabilized prosthesis.

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

    PubMed

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

    2014-04-01

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

  20. The Toxoplasma Centrocone Houses Cell Cycle Regulatory Factors.

    PubMed

    Naumov, Anatoli; Kratzer, Stella; Ting, Li-Min; Kim, Kami; Suvorova, Elena S; White, Michael W

    2017-08-22

    Our knowledge of cell cycle regulatory mechanisms in apicomplexan parasites is very limited. In this study, we describe a novel Toxoplasma gondii factor that has a vital role in chromosome replication and the regulation of cytoplasmic and nuclear mitotic structures, and we named this factor ECR1 for essential for chromosome replication 1. ECR1 was discovered by complementation of a temperature-sensitive (ts) mutant that suffers lethal, uncontrolled chromosome replication at 40°C similar to a ts mutant carrying a defect in topoisomerase. ECR1 is a 52-kDa protein containing divergent RING and TRAF-Sina-like zinc binding domains that are dynamically expressed in the tachyzoite cell cycle. ECR1 first appears in the unique spindle compartment of the Apicomplexa (centrocone) of the nuclear envelope in early S phase and then in the nucleus in late S phase where it reaches maximum expression. Following nuclear division, but before daughter parasites separate from the mother parasite, ECR1 is downregulated and is absent in new daughter parasites. The proteomics of ECR1 identified interactions with the ubiquitin-mediated protein degradation machinery and the minichromosome maintenance complex, and the loss of ECR1 led to increased stability of a key member of this complex, MCM2. ECR1 also forms a stable complex with the cyclin-dependent kinase (CDK)-related kinase, Tgondii Crk5 (TgCrk5), which displays a similar cell cycle expression and localization during tachyzoite replication. Importantly, the localization of ECR1/TgCrk5 in the centrocone indicates that this Apicomplexa-specific spindle compartment houses important regulatory factors that control the parasite cell cycle.IMPORTANCE Parasites of the apicomplexan family are important causes of human disease, including malaria, toxoplasmosis, and cryptosporidiosis. Parasite growth is the underlying cause of pathogenesis, yet despite this importance, the molecular basis for parasite replication is poorly understood. Filling

  1. Toxoplasma gondii Development of Its Replicative Niche: in Its Host Cell and Beyond

    PubMed Central

    2014-01-01

    Intracellular pathogens can replicate efficiently only after they manipulate and modify their host cells to create an environment conducive to replication. While diverse cellular pathways are targeted by different pathogens, metabolism, membrane and cytoskeletal architecture formation, and cell death are the three primary cellular processes that are modified by infections. Toxoplasma gondii is an obligate intracellular protozoan that infects ∼30% of the world's population and causes severe and life-threatening disease in developing fetuses, in immune-comprised patients, and in certain otherwise healthy individuals who are primarily found in South America. The high prevalence of Toxoplasma in humans is in large part a result of its ability to modulate these three host cell processes. Here, we highlight recent work defining the mechanisms by which Toxoplasma interacts with these processes. In addition, we hypothesize why some processes are modified not only in the infected host cell but also in neighboring uninfected cells. PMID:24951442

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

    PubMed

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

    2016-12-01

    The inner membrane complex sub-compartment has a critical role in Toxoplasma gondii endodyogeny. In this study, we investigated the protection upon intraperitoneal route (IP) challenge induced by the virus-like particles (VLPs) vaccine containing Toxoplasma gondii IMC ISP (RH strain) (Type I). Intranasal immunization with the VLPs in mice elicited enhanced systemic and mucosal Toxoplasma gondii-specific IgG, IgG1, IgG2a and IgA antibody responses, and CD4+ and CD8+ responses. Immunized mice significantly reduced T. gondii cyst burden and size in brain, resulting in cross-protection upon T. gondii (ME49) (Type II) challenge infection. These results indicate that the IP route challenge infection induced by T. gondii IMC ISP VLPs might be a very good target for vaccination representing novel approach to reduce infection. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Toxoplasma Infection in an Immunocompetent Host: Possible Risk of Living with Multiple Cats

    PubMed Central

    Sotello, David; Ameri, Allen; Abuzaid, Ahmed S; Rivas, Ana Marcella; Vashisht, Priyanka

    2017-01-01

    A 32-year-old man presented with agitation, headache, and confusion. He was immunocompetent and had been living with multiple cats for many years. His vital signs were stable. He was afebrile. Multiple blood tests did not show any serious problem. Brain magnetic resonance imaging (MRI) revealed multiple ring-enhancing white matter lesions. Cerebrospinal fluid analysis did not show any signs of infection. Based on a presumptive diagnosis of multiple sclerosis, high-dose corticosteroid treatment was started. However, this caused worsening of the symptoms and increased the size of the lesions. Corticosteroids were discontinued and biopsy was done. Biopsy of the lesions confirmed Toxoplasma gondii infection, and treatment with pyrimethamine/sulfadiazine was initiated. Treatment decreased the size of the lesions dramatically. Toxoplasma infection of the central nervous system (CNS) is rare in immunocompetent hosts. Living with multiple cats is believed to be a risk factor for Toxoplasma infection in immunocompetent hosts. PMID:28435763

  4. Survey for Toxoplasma gondii by PCR detection in meat for human consumption in Colombia.

    PubMed

    Franco-Hernandez, Erika N; Acosta, Alejandro; Cortés-Vecino, Jesús; Gómez-Marín, Jorge Enrique

    2016-02-01

    The overall risk for toxoplasmosis in meat produced in Colombia is unknown. We analyzed by PCR assay meat samples for human consumption in two types of plants in Colombia: 120 samples from class I plants (60 samples from chicken, 30 from swine and 30 from beef) and 60 from class II plants (30 samples from beef and 30 from swine). Presence of Toxoplasma DNA was established by targeted B1 nested PCR assay. We detected 79 (43%) samples that were positive by B1 nested PCR (33 from chicken, 22 from beef, and 24 from pork). No differences were found by region or species. Eleven positive samples were confirmed by sequencing of the B1 repeated region. Some polymorphisms were detected without relation with clonal groups nor meat species. Food animals are highly exposed to Toxoplasma in Colombia. Detailed studies are needed to establish the reasons for differences in Toxoplasma prevalence between farms, regarding practices of animal food production.

  5. Exploitation of auxotrophies and metabolic defects in Toxoplasma as therapeutic approaches.

    PubMed

    Coppens, Isabelle

    2014-02-01

    Like any obligate intracellular pathogen, the parasite Toxoplasma gondii has lost its capacity for living independently of another organism. Toxoplasma lacks many genes that encode for entire metabolic pathways and has, in return, expanded genes that promote nutrient scavenging to meet its basic metabolic requirements. Although sequestrated in a parasitophorous vacuole and thus insulated from the nutrient-rich host cytosol and organelles by a membrane, T. gondii has evolved efficient strategies to acquire essential metabolites from mammalian cells. This review explores the natural auxotrophies and nutrient scavenging activities of the parasite, emphasising unique transport systems and salvage pathways. We describe the mechanisms deployed by Toxoplasma to modify its parasitophorous vacuole to gain access to host cytosolic molecules and to hijack host organelles to retrieve their nutrient content. From a therapeutic perspective, we survey the different possibilities to starve T. gondii by nutrient depletion or disruption of salvage pathways.

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

    PubMed

    Hari Dass, Shantala Arundhati; Vyas, Ajai

    2014-12-01

    Male rats (Rattus novergicus) infected with protozoan Toxoplasma gondii relinquish their innate aversion to the cat odours. This behavioural change is postulated to increase transmission of the parasite to its definitive felid hosts. Here, we show that the Toxoplasma gondii infection institutes an epigenetic change in the DNA methylation of the arginine vasopressin promoter in the medial amygdala of male rats. Infected animals exhibit hypomethylation of arginine vasopressin promoter, leading to greater expression of this nonapeptide. The infection also results in the greater activation of the vasopressinergic neurons after exposure to the cat odour. Furthermore, we show that loss of fear in the infected animals can be rescued by the systemic hypermethylation and recapitulated by directed hypomethylation in the medial amygdala. These results demonstrate an epigenetic proximate mechanism underlying the extended phenotype in the Rattus novergicus-Toxoplasma gondii association.

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

    PubMed

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

    2016-12-08

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

  8. Long-term discission rate after placing posterior chamber lenses with the convex surface posterior.

    PubMed

    Downing, J E

    1986-11-01

    The incidence of secondary capsulotomy was studied in a group of 757 posterior chamber intraocular lenses placed with the convex surface posterior within the capsular bag. Minimum follow-up was 12 months and ranged up to 61 months, with a mean of 33 months. In the first year, only 2.9% of cases required discission, but this rose to 15.7% at five years. The need for capsulotomy with angled-haptic lenses was 7.9% at three years; it was 15.0% with uniplanar lenses (P = .04). This difference appeared to be due to better apposition of the optic to the posterior capsule in the angled lenses, creating a more effective barrier to epithelial pearl migration. Capsulotomy carries significant risks and lens designs that minimize the long-term need for capsulotomy should be sought. Convex posterior lenses with angled haptics have a low incidence of posterior capsule opacification.

  9. Posterior scleritis: clinical profile and imaging characteristics.

    PubMed

    Biswas, J; Mittal, S; Ganesh, S K; Shetty, N S; Gopal, L

    1998-12-01

    Posterior scleritis is relatively uncommon and is often misdiagnosed due to its protean manifestations. We report eight cases of posterior scleritis to analyse the clinical profile, ultrasonographic and computed tomography (CT) scan features of this rare disorder. Fundus findings included serous retinal detachment, choroidal folds, retinal folds, subretinal mass, choroidal detachment, disc edema, and macular edema. There was associated anterior scleritis and anterior uveitis in the majority of the cases. In all cases ultrasound with or without CT scan confirmed the clinical diagnosis. All patients responded to systemic steroids except one who required immunosuppressive therapy. This paper describes the clinical profile of a series of posterior scleritis cases highlighting varied clinical presentation, and the role of ultrasound and CT scan findings in the diagnosis.

  10. Fundus autofluorescence imaging in posterior uveitis.

    PubMed

    Durrani, Khayyam; Foster, C Stephen

    2012-01-01

    Although the phenomenon of fundus autofluorescence has been known for decades, it has only recently been recognized as a measure of retinal pigment epithelial function and health. Characteristic fundus autofluorescence patterns have been described in eyes affected by inflammation of the posterior segment, and these patterns have provided insights into the pathogenesis of posterior uveitis entities. In addition, preliminary data indicate that fundus autofluorescence characteristics may serve as markers of disease activity, allow prediction of visual prognosis, and may help determine the adequacy of therapy. We provide an overview of the current state of fundus autofluorescence imaging technology and review our current knowledge of fundus autoflourescence findings and their clinical use in the posterior uveitis entities.

  11. A technique of anterior screw removal through a posterior costotransversectomy approach for posterior-based osteotomies.

    PubMed

    Lewis, Stephen J; David, Kenny; Singer, Syndie; Bacon, Sarah A; Kopka, Michaela; Gray, Randolph; Magana, Sofia

    2010-05-15

    Case report. To describe a novel technique to remove anterior instrumentation from a posterior approach while performing posterior-based osteotomies for spinal deformities. Posterior-based osteotomies such as pedicle subtraction osteotomies (PSOs) and vertebral column resections are performed to restore sagittal alignment. The removal of previously placed anterior implants at the desired osteotomy level can often be challenging. We propose a technique for the removal of anterior instrumentation through a posterior approach to facilitate osteotomy closure and deformity correction, while avoiding the need for an anterior incision. A 34-year-old woman presented with a residual deformity after several anterior and posterior procedures. The residual coronal Cobb angle measured 60 degrees between T7 and L2, with a 46 degrees thoracolumbar kyphosis between T10 and L2. The screw head at the desired osteotomy level was in close proximity to the liver after the previous right-sided thoracoabdominal approach. Therefore, the T11 anterior screw was accessed through a posterior costotransversectomy approach and disconnected from the rod proximally and distally with a high-speed side-cutting burr. A portion of the right lateral vertebral body of T11 was removed to expose the neck of the screw, which was separated from the shaft with the same burr. A PSO was performed at T11 and the remaining screw shank was removed with the posterior-based osteotomy. No major complications were encountered during the procedure. The anterior screw at T11 was removed from posteriorly, and the PSO was completed successfully. Postoperative recovery was without incident, and the patient was very satisfied with her results. This technique describes a novel, safe, and effective method to deal with anterior instrumentation from the posterior approach while performing posterior-based osteotomies for rigid spinal deformities.

  12. Comparison of Four Commercially Available Avidity Tests for Toxoplasma gondii-Specific IgG Antibodies

    PubMed Central

    Breit, L.; Cimon, B.; Franck, J.; Fricker-Hidalgo, H.; Godineau, N.; Houze, S.; Paris, L.; Pelloux, H.; Villena, I.

    2013-01-01

    Toxoplasma infection in pregnant women may cause congenital toxoplasmosis. Diagnosis of infection is based on serological tests aimed at detecting IgM and IgG antibodies against Toxoplasma gondii. However, IgM antibodies are not an accurate marker for discriminating between acute and latent infection. Detection of residual or persistent IgM may occur months or even years after primary infection, while the IgG avidity test is a rapid means of identifying latent infections in pregnant women who exhibit both IgG and IgM anti-Toxoplasma antibodies on initial testing during pregnancy. In this study, we assessed and compared the performances of four commercially available Toxoplasma IgG avidity tests in immunocompetent and immunocompromised patients with acute and latent toxoplasmosis. The positive predictive value of high avidity to confirm latent toxoplasmosis was 100% for all the assays, indicating that high avidity is a hallmark of latent infection. However, the negative predictive value of high avidity ranged from 99.2% (bioMérieux) to 95.3% (Abbott), indicating that acute toxoplasmosis could not be reliably diagnosed based on low IgG avidity alone. Thus, the avidity test provides a rapid means for identifying latent Toxoplasma infection in immunocompetent pregnant women presenting both IgG and IgM anti-Toxoplasma antibodies on initial testing. In terms of cost-effectiveness, avidity testing is a powerful tool that optimizes screening and follow-up of pregnant women while minimizing the costs of screening by avoiding subsequent costly maternal and fetal investigation and unnecessary treatment. The cheapest assay, Vidas Toxo IgG Avidity, also had the best performance for the diagnosis of latent toxoplasmosis. PMID:23239801

  13. Fierce Competition between Toxoplasma and Chlamydia for Host Cell Structures in Dually Infected Cells

    PubMed Central

    Romano, Julia D.; de Beaumont, Catherine; Carrasco, Jose A.; Ehrenman, Karen; Bavoil, Patrik M.

    2013-01-01

    The prokaryote Chlamydia trachomatis and the protozoan Toxoplasma gondii, two obligate intracellular pathogens of humans, have evolved a similar modus operandi to colonize their host cell and salvage nutrients from organelles. In order to gain fundamental knowledge on the pathogenicity of these microorganisms, we have established a cell culture model whereby single fibroblasts are coinfected by C. trachomatis and T. gondii. We previously reported that the two pathogens compete for the same nutrient pools in coinfected cells and that Toxoplasma holds a significant competitive advantage over Chlamydia. Here we have expanded our coinfection studies by examining the respective abilities of Chlamydia and Toxoplasma to co-opt the host cytoskeleton and recruit organelles. We demonstrate that the two pathogen-containing vacuoles migrate independently to the host perinuclear region and rearrange the host microtubular network around each vacuole. However, Toxoplasma outcompetes Chlamydia to the host microtubule-organizing center to the detriment of the bacterium, which then shifts to a stress-induced persistent state. Solely in cells preinfected with Chlamydia, the centrosomes become associated with the chlamydial inclusion, while the Toxoplasma parasitophorous vacuole displays growth defects. Both pathogens fragment the host Golgi apparatus and recruit Golgi elements to retrieve sphingolipids. This study demonstrates that the productive infection by both Chlamydia and Toxoplasma depends on the capability of each pathogen to successfully adhere to a finely tuned developmental program that aims to remodel the host cell for the pathogen's benefit. In particular, this investigation emphasizes the essentiality of host organelle interception by intravacuolar pathogens to facilitate access to nutrients. PMID:23243063

  14. Comparison of four commercially available avidity tests for Toxoplasma gondii-specific IgG antibodies.

    PubMed

    Villard, O; Breit, L; Cimon, B; Franck, J; Fricker-Hidalgo, H; Godineau, N; Houze, S; Paris, L; Pelloux, H; Villena, I; Candolfi, E

    2013-02-01

    Toxoplasma infection in pregnant women may cause congenital toxoplasmosis. Diagnosis of infection is based on serological tests aimed at detecting IgM and IgG antibodies against Toxoplasma gondii. However, IgM antibodies are not an accurate marker for discriminating between acute and latent infection. Detection of residual or persistent IgM may occur months or even years after primary infection, while the IgG avidity test is a rapid means of identifying latent infections in pregnant women who exhibit both IgG and IgM anti-Toxoplasma antibodies on initial testing during pregnancy. In this study, we assessed and compared the performances of four commercially available Toxoplasma IgG avidity tests in immunocompetent and immunocompromised patients with acute and latent toxoplasmosis. The positive predictive value of high avidity to confirm latent toxoplasmosis was 100% for all the assays, indicating that high avidity is a hallmark of latent infection. However, the negative predictive value of high avidity ranged from 99.2% (bioMérieux) to 95.3% (Abbott), indicating that acute toxoplasmosis could not be reliably diagnosed based on low IgG avidity alone. Thus, the avidity test provides a rapid means for identifying latent Toxoplasma infection in immunocompetent pregnant women presenting both IgG and IgM anti-Toxoplasma antibodies on initial testing. In terms of cost-effectiveness, avidity testing is a powerful tool that optimizes screening and follow-up of pregnant women while minimizing the costs of screening by avoiding subsequent costly maternal and fetal investigation and unnecessary treatment. The cheapest assay, Vidas Toxo IgG Avidity, also had the best performance for the diagnosis of latent toxoplasmosis.

  15. Insights into inflammatory bowel disease using Toxoplasma gondii as an infectious trigger

    PubMed Central

    Egan, Charlotte E; Cohen, Sara B; Denkers, Eric Y

    2014-01-01

    Oral infection of certain inbred mouse strains with the protozoan Toxoplasma gondii triggers inflammatory pathology resembling lesions seen during human inflammatory bowel disease, in particular Crohn's disease (CD). Damage triggered by the parasite is largely localized to the distal portion of the small intestine, and as such is one of only a few models for ileal inflammation. This is important because ileal involvement is a characteristic of CD in over two-thirds of patients. The disease induced by Toxoplasma is mediated by Th1 cells and the cytokines tumor necrosis factor-α and interferon-γ. Inflammation is dependent upon IL-23, also identified by genome-wide association studies as a risk factor in CD. Development of lesions is concomitant with emergence of E. coli that display enhanced adhesion to the intestinal epithelium and subepithelial translocation. Furthermore, depletion of gut flora renders mice resistant to Toxoplasma-triggered ileitis. Recent findings suggest complex CCR2-dependent interactions between lamina propria T cells and intraepithelial lymphocytes in fueling proinflammatory pathology in the intestine. The advantage of the Toxoplasma model is that disease develops rapidly (within 7–10 days of infection) and can be induced in immunodeficient mice by adoptive transfer of mucosal T cells from infected donors. We propose that Toxoplasma acts as a trigger setting into motion a series of events culminating in loss of tolerance in the intestine and emergence of pathogenic T cell effectors. The Toxoplasma trigger model is providing new leaps in our understanding of immunity in the intestine. PMID:22064707

  16. Fierce competition between Toxoplasma and Chlamydia for host cell structures in dually infected cells.

    PubMed

    Romano, Julia D; de Beaumont, Catherine; Carrasco, Jose A; Ehrenman, Karen; Bavoil, Patrik M; Coppens, Isabelle

    2013-02-01

    The prokaryote Chlamydia trachomatis and the protozoan Toxoplasma gondii, two obligate intracellular pathogens of humans, have evolved a similar modus operandi to colonize their host cell and salvage nutrients from organelles. In order to gain fundamental knowledge on the pathogenicity of these microorganisms, we have established a cell culture model whereby single fibroblasts are coinfected by C. trachomatis and T. gondii. We previously reported that the two pathogens compete for the same nutrient pools in coinfected cells and that Toxoplasma holds a significant competitive advantage over Chlamydia. Here we have expanded our coinfection studies by examining the respective abilities of Chlamydia and Toxoplasma to co-opt the host cytoskeleton and recruit organelles. We demonstrate that the two pathogen-containing vacuoles migrate independently to the host perinuclear region and rearrange the host microtubular network around each vacuole. However, Toxoplasma outcompetes Chlamydia to the host microtubule-organizing center to the detriment of the bacterium, which then shifts to a stress-induced persistent state. Solely in cells preinfected with Chlamydia, the centrosomes become associated with the chlamydial inclusion, while the Toxoplasma parasitophorous vacuole displays growth defects. Both pathogens fragment the host Golgi apparatus and recruit Golgi elements to retrieve sphingolipids. This study demonstrates that the productive infection by both Chlamydia and Toxoplasma depends on the capability of each pathogen to successfully adhere to a finely tuned developmental program that aims to remodel the host cell for the pathogen's benefit. In particular, this investigation emphasizes the essentiality of host organelle interception by intravacuolar pathogens to facilitate access to nutrients.

  17. A retrospective study of posterior malleolus fractures.

    PubMed

    Xu, Hai-lin; Li, Xuan; Zhang, Dian-ying; Fu, Zhong-guo; Wang, Tian-bing; Zhang, Pei-xun; Jiang, Bao-guo; Shen, Hui-liang; Wang, Gang; Wang, Guang-lin; Wu, Xin-bao

    2012-09-01

    In this retrospective study, we evaluated the treatment effect of ankle joint fracture surgery involving the posterior malleolus, and discuss relevant factors influencing the occurrence of traumatic arthritis of the ankle joint. A total of 102 cases of ankle joint fractures involving the posterior malleolus in five large-scale skeletal trauma centres in China, from January 2000 to July 2009, were retrospectively analysed in terms of surgical treatment and complete follow-up. Ankle joint mobility, posterior malleolus fragment size, articular surface evenness, Ankle-Hindfoot Scale of the American Orthopedic Foot and Ankle Society (AOFAS) score, and imaging scale score for arthritis were recorded. The degree of fracture pain during rest, active movement, and weight-bearing walking, and satisfaction with treatment were evaluated using a visual analogue scale (VAS). The average AOFAS score was 95.9, excellence rate was 92.2 %, and average VAS scores for degree of fracture pain during rest, active movement, and weight-bearing walking were 0.15, 0.31, and 0.68, respectively. Thirty-six cases showed arthritic manifestations. Ankle joint mobility along all directions on the injured side was lower than that on the unaffected side. There was no obvious difference in treatment effect between the fixed and unfixed posterior malleolus fragment groups for all and for fragment size of < 25 %; between fixing the posterior malleolus fragment from front to back or from back to front; or between elderly patients (≥ 60 years old) and young patients (< 60 years old). There was a distinct difference in the treatment effect between articular surface evenness and unevenness for all and for fragment size of ≥ 25 %. For all 102 cases of ankle joint fracture involving the posterior malleolus, the treatment effect was satisfactory. Restoration of an even articular surface, especially when fragment size ≥ 25 %, should be attempted during treatment.

  18. Posterior predictive checking of multiple imputation models.

    PubMed

    Nguyen, Cattram D; Lee, Katherine J; Carlin, John B

    2015-07-01

    Multiple imputation is gaining popularity as a strategy for handling missing data, but there is a scarcity of tools for checking imputation models, a critical step in model fitting. Posterior predictive checking (PPC) has been recommended as an imputation diagnostic. PPC involves simulating "replicated" data from the posterior predictive distribution of the model under scrutiny. Model fit is assessed by examining whether the analysis from the observed data appears typical of results obtained from the replicates produced by the model. A proposed diagnostic measure is the posterior predictive "p-value", an extreme value of which (i.e., a value close to 0 or 1) suggests a misfit between the model and the data. The aim of this study was to evaluate the performance of the posterior predictive p-value as an imputation diagnostic. Using simulation methods, we deliberately misspecified imputation models to determine whether posterior predictive p-values were effective in identifying these problems. When estimating the regression parameter of interest, we found that more extreme p-values were associated with poorer imputation model performance, although the results highlighted that traditional thresholds for classical p-values do not apply in this context. A shortcoming of the PPC method was its reduced ability to detect misspecified models with increasing amounts of missing data. Despite the limitations of posterior predictive p-values, they appear to have a valuable place in the imputer's toolkit. In addition to automated checking using p-values, we recommend imputers perform graphical checks and examine other summaries of the test quantity distribution. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Posterior cortical atrophy: a brief review.

    PubMed

    Kirshner, Howard S; Lavin, Patrick J M

    2006-11-01

    Posterior cortical atrophy is a striking clinical syndrome in which a dementing illness begins with visual symptoms. Initially, the problem may seem to be loss of elementary vision, but over time the patient develops features of visual agnosia, topographical difficulty, optic ataxia, simultanagnosia, ocular apraxia (Balint's syndrome), alexia, acalculia, right-left confusion, and agraphia (Gerstmann's syndrome), and later a more generalized dementia. Occasional patients have visual hallucinations and signs of Parkinson's disease or Lewy body dementia. A number of different neuropathologic disorders are associated with posterior cortical atrophy.

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

    PubMed

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

    2010-08-01

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

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

    NASA Astrophysics Data System (ADS)

    Soldati, Dominique; Boothroyd, John C.

    1993-04-01

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

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

    PubMed

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

    2006-09-01

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

  3. Characterization of Toxoplasma gondii 5' UTR with encyclopedic TSS information.

    PubMed

    Yamagishi, J; Watanabe, J; Goo, Y K; Masatani, T; Suzuki, Y; Xuan, X

    2012-04-01

    The 5' UTR is widely involved in gene expression via post-transcriptional regulation. However, a detailed profile of the 5' UTR for Toxoplasma gondii has not yet been demonstrated. To investigate the issue, we compared the predicted open reading frames (ORFs) and transcription start sites (TSSs) of T. gondii obtained by TSS-seq, a method that enables analysis of encyclopedic TSSs with next-generation sequencers. As a result, it was demonstrated that the mode length of the 5' UTR is between 120 and 140 nucleotides (nts) when a subset of genes with predicted signal peptides was examined. However, when genes without the signal peptide were examined, the length was extended to approximately 600 nts. Because additional information on the predicted signal peptide generates increased reliability to the 5' end estimation of each ORF, we believe that the former value was more reliable as a representative of the 5' UTR length of T. gondii. The discrepancy suggests that current predictions of the 5' end of the ORF were less accurate and considerably more discordant with the natural status. The 5' untranslated region (5' UTR) is defined as that between the 5' end of the transcripts and just in front of a start codon of an ORF. Therefore, the 5' UTR does not contain any information for a protein sequence; however, it is involved in the control of protein expression via the modulation of translational efficiency (Kozak, 1991b; Hughes, 2006).

  4. Inhibition and Structure of Toxoplasma gondii Purine Nucleoside Phosphorylase

    PubMed Central

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

    2014-01-01

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

  5. Deciphering the Draft Genome of Toxoplasma gondii RH Strain

    PubMed Central

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

    2016-01-01

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

  6. Effects of Toxoplasma gondii infection on the brain.

    PubMed

    Carruthers, Vern B; Suzuki, Yasuhiro

    2007-05-01

    Toxoplasma gondii, an intracellular protozoan parasite, can infect humans in 3 different ways: ingestion of tissue cysts, ingestion of oocysts, or congenital infection with tachyzoites. After proliferation of tachyzoites in various organs during the acute stage, the parasite forms cysts preferentially in the brain and establishes a chronic infection, which is a balance between host immunity and the parasite's evasion of the immune response. A variety of brain cells, including astrocytes and neurons, can be infected. In vitro studies using non-brain cells have demonstrated profound effects of the infection on gene expression of host cells, including molecules that promote the immune response and those involved in signal transduction pathways, suggesting that similar effects could occur in infected brain cells. Interferon-gamma is the essential mediator of the immune response to control T. gondii in the brain and to maintain the latency of chronic infection. Infection also induces the production of a variety of cytokines by microglia, astrocytes, and neurons, which promote or suppress inflammatory responses. The strain (genotype) of T. gondii, genetic factors of the host, and probably the route of infection and the stage (tachyzoite, cyst, or oocyst) of the parasite initiating infection all contribute to the establishment of a balance between the host and the parasite and affect the outcome of the infection.

  7. Effects of Toxoplasma gondii Infection on the Brain

    PubMed Central

    Carruthers, Vern B.; Suzuki, Yasuhiro

    2007-01-01

    Toxoplasma gondii, an intracellular protozoan parasite, can infect humans in 3 different ways: ingestion of tissue cysts, ingestion of oocysts, or congenital infection with tachyzoites. After proliferation of tachyzoites in various organs during the acute stage, the parasite forms cysts preferentially in the brain and establishes a chronic infection, which is a balance between host immunity and the parasite's evasion of the immune response. A variety of brain cells, including astrocytes and neurons, can be infected. In vitro studies using non-brain cells have demonstrated profound effects of the infection on gene expression of host cells, including molecules that promote the immune response and those involved in signal transduction pathways, suggesting that similar effects could occur in infected brain cells. Interferon-γ is the essential mediator of the immune response to control T. gondii in the brain and to maintain the latency of chronic infection. Infection also induces the production of a variety of cytokines by microglia, astrocytes, and neurons, which promote or suppress inflammatory responses. The strain (genotype) of T. gondii, genetic factors of the host, and probably the route of infection and the stage (tachyzoite, cyst, or oocyst) of the parasite initiating infection all contribute to the establishment of a balance between the host and the parasite and affect the outcome of the infection. PMID:17322557

  8. Multidisciplinary approach to congenital Toxoplasma infection: an Italian nationwide survey.

    PubMed

    Tomasoni, Lina R; Meroni, Valeria; Bonfanti, Carlo; Bollani, Lina; Lanzarini, Paolo; Frusca, Tiziana; Castelli, Francesco

    2014-07-01

    Italy provides a free voluntary serological screening for toxoplasmosis in pregnancy supported by public health system, as there is an estimated congenital toxoplasmosis rate of 1-2/10,000. The aim of this study was to make an inventory of diagnostic and therapeutic protocols in use in Italy in the absence of a national guideline. A semistructured questionnaire was distributed to AMCLI (Italian Association of Clinical Microbiologists) members who were asked to involve other specialists to fill in the form. Data from 26 centers show: a) a general use of the IgG avidity test to solve diagnosis in IgG/IgM positive, pregnant women; b) a widespread attitude to spyramicin antenatal treatment in suspected, unconfirmed maternal infection; c) avoidance of invasive antenatal diagnosis only in suspected early or late (>24 weeks), even confirmed, maternal infection d) fetal diagnosis performed by PCR assays on amniotic fluid; e) variability of both indications and dosage of pyrimethamine-sulfadiazine (P-S) as fetal treatment; f) use of comparative mother and newborn IgG/IgM Immuneblot in most centers; g) no diagnostic tests performed on placenta and cord blood; h) spyramicin is no longer used in congenital infections; i) no P-S-based treatment for children at high risk of congenital infection (late maternal infection) in the absence of diagnosis. As there is the opportunity to test pregnant women for Toxoplasma gondii infection in Italy free of charge, standardized diagnostic and therapeutic national guidelines would focus on a more uniform approach.

  9. Detection of Toxoplasma gondii antibodies in Antarctic pinnipeds.

    PubMed

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

    2012-11-23

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

  10. Genetic diversity among sea otter isolates of Toxoplasma gondii

    USGS Publications Warehouse

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

    2008-01-01

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

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

    PubMed Central

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

    2014-01-01

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

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

    SciTech Connect

    Boucher, Lauren E.; Bosch, Jürgen

    2014-08-29

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

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

    PubMed

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

    2015-12-01

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

  14. The Import of Proteins into the Mitochondrion of Toxoplasma gondii.

    PubMed

    van Dooren, Giel G; Yeoh, Lee M; Striepen, Boris; McFadden, Geoffrey I

    2016-09-09

    Outside of well characterized model eukaryotes, relatively little is known about the translocons that transport proteins across the two membranes that surround the mitochondrion. Apicomplexans are a phylum of intracellular parasites that cause major diseases in humans and animals and are evolutionarily distant from model eukaryotes such as yeast. Apicomplexans harbor a mitochondrion that is essential for parasite survival and is a validated drug target. Here, we demonstrate that the apicomplexan Toxoplasma gondii harbors homologues of proteins from all the major mitochondrial protein translocons present in yeast, suggesting these arose early in eukaryotic evolution. We demonstrate that a T. gondii homologue of Tom22 (TgTom22), a central component of the translocon of the outer mitochondrial membrane (TOM) complex, is essential for parasite survival, mitochondrial protein import, and assembly of the TOM complex. We also identify and characterize a T. gondii homologue of Tom7 (TgTom7) that is important for parasite survival and mitochondrial protein import. Contrary to the role of Tom7 in yeast, TgTom7 is important for TOM complex stability, suggesting the role of this protein has diverged during eukaryotic evolution. Together, our study identifies conserved and modified features of mitochondrial protein import in apicomplexan parasites. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  15. 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.

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

    PubMed

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

    2017-05-01

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

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

    PubMed

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

    2017-03-01

    Toxoplasma gondii is one of the most successful pathogens on earth, capable of infecting an extremely broad range of mammals and birds and causing potentially fatal disease in humans. The house mouse (Mus musculus) has been used as the primary laboratory animal model for determining the virulence of T. gondii strains. Epidemiological evidence also suggests a potential association between virulence in mice and disease severity in human toxoplasmosis. However, many factors can affect virulence measurements, including route of infection, life stage of the parasite, number of passages of the parasite in mice or cell culture, and the mouse host line used. Variability among these factors makes it difficult to compare results between different studies in different laboratories. Here, we discuss important factors that should be considered when carrying out T. gondii murine virulence assays and propose a standardized methodology that should facilitate integration of T. gondii virulence data throughout the research community in future studies and thereby enable more efficient and effective analysis of genetic and virulence patterns for this important parasite. Copyright © 2017 Elsevier Inc. All rights reserved.

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

    PubMed

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

    2015-08-01

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

  19. Membrane Topology and Transient Acylation of Toxoplasma gondii Glycosylphosphatidylinositols

    PubMed Central

    Kimmel, Jürgen; Smith, Terry K.; Azzouz, Nahid; Gerold, Peter; Seeber, Frank; Lingelbach, Klaus; Dubremetz, Jean-François; Schwarz, Ralph T.

    2006-01-01

    Using hypotonically permeabilized Toxoplasma gondii tachyzoites, we investigated the topology of the free glycosylphosphatidylinositols (GPIs) within the endoplasmic reticulum (ER) membrane. The morphology and permeability of parasites were checked by electron microscopy and release of a cytosolic protein. The membrane integrity of organelles (ER and rhoptries) was checked by protease protection assays. In initial experiments, GPI biosynthetic intermediates were labeled with UDP-[6-3H]GlcNAc in permeabilized parasites, and the transmembrane distribution of the radiolabeled lipids was probed with phosphatidylinositol-specific phospholipase C (PI-PLC). A new early intermediate with an acyl modification on the inositol was identified, indicating that inositol acylation also occurs in T. gondii. A significant portion of the early GPI intermediates (GlcN-PI and GlcNAc-PI) could be hydrolyzed following PI-PLC treatment, indicating that these glycolipids are predominantly present in the cytoplasmic leaflet of the ER. Permeabilized T. gondii parasites labeled with either GDP-[2-3H]mannose or UDP-[6-3H]glucose showed that the more mannosylated and side chain (Glc-GalNAc)-modified GPI intermediates are also preferentially localized in the cytoplasmic leaflet of the ER. PMID:16896225

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

    SciTech Connect

    Swartz, R.P.

    1982-01-01

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

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

    PubMed

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

    2016-04-01

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

  2. The Ultrastructural Effects of Sulfachloropyrazine on Toxoplasma gondii Tachyzoites

    PubMed Central

    Zeng, YB; Dong, H; Han, HY; Jiang, LL; Zhao, QP; Zhu, SH; Ma, WJ; Cheng, J; Huang, B

    2013-01-01

    Background Toxoplasmosis is one of the most common parasitic infections of humans and other mammals. This study was aimed to understand the mechanism of action of veterinary medicine-sulfachloropyrazine (SPZ, 99.97%) against Toxoplasma gondii. Methods T. gondii tachyzoites were soaked in PBS (as a control) or SPZ (250 mg/mL) for 2 h at 37 °C. After being processed, any ultrastructural changes of the tachyzoites that had occurred were observed by Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). Results The tachyzoites from control groups with a uniform size had a smooth surface and intact cell or nuclear membranes. In addition, an oval-shaped nucleus, conoids and micronemes were also observed. By contrast, many parasites from the SPZ-treated groups were detrimentally affected by the treatment. Some appeared to be of the vacuolization in their cytoplasm, with the substantial reduction in the number of dense granules and the blur of some organelles. Conclusion The morphology and ultrastructure of tachyzoites can be affected significantly by SPZ, which might kill the parasite by inhibiting its energy metabolism, inducing apoptosis and damaging its structure. The study provides an experimental basis for further study on the mechanism of SPZ against T. gondii. PMID:23682263

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

    PubMed

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

    2013-01-01

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

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

    PubMed

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

    2016-01-01

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

  5. Genetic diversity among sea otter isolates of Toxoplasma gondii.

    PubMed

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

    2008-02-14

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

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

    PubMed

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

    2015-10-01

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

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

    PubMed

    Gennari, Solange M; Niemeyer, Claudia; Soares, Herbert S; Musso, Cesar M; Siqueira, Glauber C C; Catão-Dias, José L; Dias, Ricardo A; Dubey, Jitender P

    2016-08-15

    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 National Marine Park, which is a conservation area protected by the Brazilian government. The objective of this study was to determine the occurrence of T. gondii antibodies in sera of seabird's species Sula spp. and Phaeton spp. from breeding colonies located in the Islands of Santa Bárbara and Redonda, Abrolhos's archipelago. Sera were tested by modified agglutination test, first screened at 1:5 dilution (cut-off point) and the positive samples were titrated at a two-fold serial dilution. Serum samples were obtained from 69 birds of four species: Sula dactylatra (23 birds), Sula leucogaster (19 birds), Phaeton aethereus (25 birds) and Phaeton lepturus (2 birds). Antibodies to T. gondii were found in 24 (34.8%) of 69 seabirds with titers that ranged from 5 to 640. Occurrence value in S. dactylatra was 34.8% (8/23), in S. leucogaster was 47.4% (9/19), in P. aethereus was 28% (7/25) and the 2 P. lepturus were negative. This is the first description of T. gondii antibodies in free ranging seabirds of the orders Suliformes and Phaethontiformes. Copyright © 2016 Elsevier B.V. All rights reserved.

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed

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

    2015-07-21

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

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

    PubMed

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

    2007-09-30

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

  11. Evaluation of novel oocyst wall protein candidates of Toxoplasma gondii.

    PubMed

    Salman, Doaa; Okuda, Liria Hiromi; Ueno, Akio; Dautu, George; Zhang, Feifei; Igarashi, Makoto

    2017-10-01

    Oocyst stage of Toxoplasma gondii is characterized by a durable wall that confers a strong protection to this protozoan parasite in face of harsh environmental conditions. Thus, it is considered the key for transmission of T. gondii. Analysis of oocyst wall composition is mandatory therefore; the aim of this study was to identify novel T. gondii oocyst wall proteins and test their use in detection of these oocysts in environmental samples. Five candidates of novel T. gondii oocyst wall proteins (TgOWPs) were identified and named TgOWP8 through TgOWP12. Recombinant protein of TgOWP8 was expressed in E. coli using glutathione S-transferase as fusion protein. Polyclonal antibody was produced and validated by indirect immunofluorescence antibody assay (IFA). For detection by IFA, we used different methods for fixation and permeabilization of oocysts to improve the antigen-antibody detection. Specificity to wall of T. gondii oocyst was confirmed and revealed absence of cross reactivity with bradyzoite cyst wall and tachyzoites. Although some TgOWPs were identified previously, our study represents a continuation of molecular investigations of oocyst wall proteins as an essential structure for the longevity and infectivity of this stage and also provided new trial to improve T. gondii oocysts detection. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  12. 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.

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

    PubMed

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

    2007-12-01

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

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

    PubMed

    Quirk, Travis; Dubey, J P

    2008-06-01

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

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

    PubMed

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

    2011-11-01

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

  16. Identifying Novel B Cell Epitopes within Toxoplasma gondii GRA6

    PubMed Central

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

    2016-01-01

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

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

    PubMed

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

    2015-07-31

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

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

    PubMed

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

    2016-01-27

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

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

    PubMed Central

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

    2016-01-01

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

  20. 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.

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

    PubMed

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

    2004-04-01

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

  2. 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.

  3. 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.

  4. Toxoplasma Modulates Signature Pathways of Human Epilepsy, Neurodegeneration & Cancer.

    PubMed

    Ngô, Huân M; Zhou, Ying; Lorenzi, Hernan; Wang, Kai; Kim, Taek-Kyun; Zhou, Yong; El Bissati, Kamal; Mui, Ernest; Fraczek, Laura; Rajagopala, Seesandra V; Roberts, Craig W; Henriquez, Fiona L; Montpetit, Alexandre; Blackwell, Jenefer M; Jamieson, Sarra E; Wheeler, Kelsey; Begeman, Ian J; Naranjo-Galvis, Carlos; Alliey-Rodriguez, Ney; Davis, Roderick G; Soroceanu, Liliana; Cobbs, Charles; Steindler, Dennis A; Boyer, Kenneth; Noble, A Gwendolyn; Swisher, Charles N; Heydemann, Peter T; Rabiah, Peter; Withers, Shawn; Soteropoulos, Patricia; Hood, Leroy; McLeod, Rima

    2017-09-13

    One third of humans are infected lifelong with the brain-dwelling, protozoan parasite, Toxoplasma gondii. Approximately fifteen million of these have congenital toxoplasmosis. Although neurobehavioral disease is associated with seropositivity, causality is unproven. To better understand what this parasite does to human brains, we performed a comprehensive systems analysis of the infected brain: We identified susceptibility genes for congenital toxoplasmosis in our cohort of infected humans and found these genes are expressed in human brain. Transcriptomic and quantitative proteomic analyses of infected human, primary, neuronal stem and monocytic cells revealed effects on neurodevelopment and plasticity in neural, immune, and endocrine networks. These findings were supported by identification of protein and miRNA biomarkers in sera of ill children reflecting brain damage and T. gondii infection. These data were deconvoluted using three systems biology approaches: "Orbital-deconvolution" elucidated upstream, regulatory pathways interconnecting human susceptibility genes, biomarkers, proteomes, and transcriptomes. "Cluster-deconvolution" revealed visual protein-protein interaction clusters involved in processes affecting brain functions and circuitry, including lipid metabolism, leukocyte migration and olfaction. Finally, "disease-deconvolution" identified associations between the parasite-brain interactions and epilepsy, movement disorders, Alzheimer's disease, and cancer. This "reconstruction-deconvolution" logic provides templates of progenitor cells' potentiating effects, and components affecting human brain parasitism and diseases.

  5. 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.

  6. Isolation and Genotyping of Toxoplasma gondii in Brazilian Dogs

    PubMed Central

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

    2017-01-01

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

  7. Host metabolism regulates growth and differentiation of Toxoplasma gondii

    PubMed Central

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

    2012-01-01

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

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

    PubMed Central

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

    2016-01-01

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

  9. Comprehensive Proteomic Analysis of Membrane Proteins in Toxoplasma gondii*

    PubMed Central

    Che, Fa-Yun; Madrid-Aliste, Carlos; Burd, Berta; Zhang, Hongshan; Nieves, Edward; Kim, Kami; Fiser, Andras; Angeletti, Ruth Hogue; Weiss, Louis M.

    2011-01-01

    Toxoplasma gondii (T. gondii) is an obligate intracellular protozoan parasite that is an important human and animal pathogen. Experimental information on T. gondii membrane proteins is limited, and the majority of gene predictions with predicted transmembrane motifs are of unknown function. A systematic analysis of the membrane proteome of T. gondii is important not only for understanding this parasite's invasion mechanism(s), but also for the discovery of potential drug targets and new preventative and therapeutic strategies. Here we report a comprehensive analysis of the membrane proteome of T. gondii, employing three proteomics strategies: one-dimensional gel liquid chromatography-tandem MS analysis (one-dimensional gel electrophoresis LC-MS/MS), biotin labeling in conjunction with one-dimensional gel LC-MS/MS analysis, and a novel strategy that combines three-layer “sandwich” gel electrophoresis with multidimensional protein identification technology. A total of 2241 T. gondii proteins with at least one predicted transmembrane segment were identified and grouped into 841 sequentially nonredundant protein clusters, which account for 21.8% of the predicted transmembrane protein clusters in the T. gondii genome. A large portion (42%) of the identified T. gondii membrane proteins are hypothetical proteins. Furthermore, many of the membrane proteins validated by mass spectrometry are unique to T. gondii or to the Apicomplexa, providing a set of gene predictions ripe for experimental investigation, and potentially suitable targets for the development of therapeutic strategies. PMID:20935347

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

    PubMed

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

    2017-03-01

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

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

    PubMed Central

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

    2009-01-01

    The genome of the protozoan parasite Toxoplasma gondii was found to contain two genes encoding tyrosine hydroxylase; that produces l-DOPA. The encoded enzymes metabolize phenylalanine as well as tyrosine with substrate preference for tyrosine. Thus the enzymes catabolize phenylalanine to tyrosine and tyrosine to l-DOPA. The catalytic domain descriptive of this class of enzymes is conserved with the parasite enzyme and exhibits similar kinetic properties to metazoan tyrosine hydroxylases, but contains a unique N-terminal extension with a signal sequence motif. One of the genes, TgAaaH1, is constitutively expressed while the other gene, TgAaaH2, is induced during formation of the bradyzoites of the cyst stages of the life cycle. This is the first description of an aromatic amino acid hydroxylase in an apicomplexan parasite. Extensive searching of apicomplexan genome sequences revealed an ortholog in Neospora caninum but not in Eimeria, Cryptosporidium, Theileria, or Plasmodium. Possible role(s) of these bi-functional enzymes during host infection are discussed. PMID:19277211

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

    PubMed

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

    2016-01-18

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

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

    PubMed Central

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

    2016-01-01

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

  14. Optimization of Toxoplasma gondii cultivation in VERO cell line.

    PubMed

    Saadatnia, G; Haj Ghani, H; Khoo, B Y; Maimunah, A; Rahmah, N

    2010-04-01

    In vitro culture of Toxoplasma gondii can provide tachyzoites which are active, viable and with desirable purity. Thus the aim of this study was to optimize the cell culture method for T. gondii propagation to obtain a consistent source of parasites with maximum yield and viability, but minimum host cell contamination for use in production of excretory-secretory antigen. Tachyzoites with seed counts of 1x10(6), 1x10(7) and 1x10(8) harvested from infected mice were added to VERO cells of different degrees of confluence, namely 50%, 85% and 100%, and examined periodically using an inverted microscope. When the maximum release of the tachyzoites was observed from the host cells, the culture supernatant was removed and the tachyzoites harvested. Using a Neubauer chamber, the percentages of viable tachyzoites and host cell contamination were determined using trypan blue stain. Parameters that gave the best yield and purity of viable tachyzoites were found to be as follows: VERO cells at 85% confluence in DMEM medium and inoculum comprising 1x10(7) tachyzoites. After about 3 days post infection, the tachyzoites multiplied 78x, with a yield of ~7.8x10(8) per flask, 99% viability and 3% host cell contamination. This study has successfully optimized the method of propagation of T. gondii tachyzoites in VERO cells which produce parasites with high yield, purity and viability.

  15. Dynamics of the Toxoplasma gondii inner membrane complex

    PubMed Central

    Ouologuem, Dinkorma T.; Roos, David S.

    2014-01-01

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

  16. 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

  17. Plasticity between MyoC- and MyoA-Glideosomes: An Example of Functional Compensation in Toxoplasma gondii Invasion

    PubMed Central

    Frénal, Karine; Marq, Jean-Baptiste; Jacot, Damien; Polonais, Valérie; Soldati-Favre, Dominique

    2014-01-01

    The glideosome is an actomyosin-based machinery that powers motility in Apicomplexa and participates in host cell invasion and egress from infected cells. The central component of the glideosome, myosin A (MyoA), is a motor recruited at the pellicle by the acylated gliding-associated protein GAP45. In Toxoplasma gondii, GAP45 also contributes to the cohesion of the pellicle, composed of the inner membrane complex (IMC) and the plasma membrane, during motor traction. GAP70 was previously identified as a paralog of GAP45 that is tailored to recruit MyoA at the apical cap in the coccidian subgroup of the Apicomplexa. A third member of this family, GAP80, is demonstrated here to assemble a new glideosome, which recruits the class XIV myosin C (MyoC) at the basal polar ring. MyoC shares the same myosin light chains as MyoA and also interacts with the integral IMC proteins GAP50 and GAP40. Moreover, a central component of this complex, the IMC-associated protein 1 (IAP1), acts as the key determinant for the restricted localization of MyoC to the posterior pole. Deletion of specific components of the MyoC-glideosome underscores the installation of compensatory mechanisms with components of the MyoA-glideosome. Conversely, removal of MyoA leads to the relocalization of MyoC along the pellicle and at the apical cap that accounts for residual invasion. The two glideosomes exhibit a considerable level of plasticity to ensure parasite survival. PMID:25393004

  18. 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

  19. Toxoplasma gondii – Prevalence and Risk Factors in HIV-infected Patients from Songklanagarind Hospital, Southern Thailand

    PubMed Central

    Chemoh, Waenurama; Sawangjaroen, Nongyao; Siripaitoon, Pisut; Andiappan, Hemah; Hortiwakul, Thanaporn; Sermwittayawong, Natthawan; Charoenmak, Bunsri; Nissapatorn, Veeranoot

    2015-01-01

    Toxoplasmosis is one of the most common opportunistic parasitic diseases in patients living with HIV/AIDS. This study aimed to determine the seroprevalence of Toxoplasma infection in HIV-infected patients and to identify associated risk factors in Toxoplasma seropositive patients. This study was conducted at a regional public hospital in Hat Yai, southern Thailand during October 2009 to June 2010. Blood samples were collected from 300 HIV-infected patients. Each subject also answered a socio-demographic and risk factors associated with Toxoplasma infection. The prevalence of anti-Toxoplasma IgG antibodies in HIV-infected patients was 109 (36.3%), of which 83 (76.2%) had past infection and 26 (23.9%) had recently acquired Toxoplasma infection as indicated by their IgG avidity. Multivariate analysis using logistic regression showed that gender difference (adjusted OR = 1.69, 95% CI = 1.05–2.72) was the only factor associated with Toxoplasma infection. From the results obtained, these HIV-infected patients could be at high risk of developing clinical evidence of severe toxoplasmosis. Therefore, it is necessary to introduce primary behavioral practices to prevent Toxoplasma infection among HIV-infected patients. PMID:26635769

  20. Infection by Toxoplasma gondii specifically induces host c-Myc and the genes this pivotal transcription factor regulates.

    PubMed

    Franco, Magdalena; Shastri, Anjali J; Boothroyd, John C

    2014-04-01

    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.

  1. Fuchs's heterochromic cyclitis and posterior capsulotomy.

    PubMed Central

    Roussel, T J; Coster, D J

    1985-01-01

    We report a case of intractable glaucoma following an uncomplicated secondary posterior capsulotomy in a 48-year-old male with Fuchs's heterochromic cyclitis. The patient had been free of inflammation and glaucoma since cataract extraction 27 years previously. We also report the results of phenotypic analysis of lymphocytes removed from the anterior chamber. Images PMID:3859323

  2. Posterior Probabilities for a Consensus Ordering.

    ERIC Educational Resources Information Center

    Fligner, Michael A.; Verducci, Joseph S.

    1990-01-01

    The concept of consensus ordering is defined, and formulas for exact and approximate posterior probabilities for consensus ordering are developed under the assumption of a generalized Mallows' model with a diffuse conjugate prior. These methods are applied to a data set concerning 98 college students. (SLD)

  3. Posterior Predictive Model Checking in Bayesian Networks

    ERIC Educational Resources Information Center

    Crawford, Aaron

    2014-01-01

    This simulation study compared the utility of various discrepancy measures within a posterior predictive model checking (PPMC) framework for detecting different types of data-model misfit in multidimensional Bayesian network (BN) models. The investigated conditions were motivated by an applied research program utilizing an operational complex…

  4. Posterior Predictive Model Checking in Bayesian Networks

    ERIC Educational Resources Information Center

    Crawford, Aaron

    2014-01-01

    This simulation study compared the utility of various discrepancy measures within a posterior predictive model checking (PPMC) framework for detecting different types of data-model misfit in multidimensional Bayesian network (BN) models. The investigated conditions were motivated by an applied research program utilizing an operational complex…

  5. Posterior Probabilities for a Consensus Ordering.

    ERIC Educational Resources Information Center

    Fligner, Michael A.; Verducci, Joseph S.

    1990-01-01

    The concept of consensus ordering is defined, and formulas for exact and approximate posterior probabilities for consensus ordering are developed under the assumption of a generalized Mallows' model with a diffuse conjugate prior. These methods are applied to a data set concerning 98 college students. (SLD)

  6. Posterior instability caused by batter's shoulder.

    PubMed

    Kang, Richard W; Mahony, Gregory T; Harris, Thomas C; Dines, Joshua S

    2013-10-01

    In summary, batter’s shoulder is a rare and only recently recognized entity. This condition is posterior shoulder instability caused by a missed attempt at hitting a pitch, especially with an outside pitch. The lack of counterforce from hitting a ball produces increased forces imparted on the posterior capsulolabral complex of the lead shoulder during batting. If the player fails conservative management, she or he can undergo an arthroscopic posterior labral repair instead of debridement. After treatment, the player can expect to return to play after approximately 6 to 7 months. Initial results from a small, retrospective series demonstrate greater than 90% excellent results. These findings are similar to current literature for arthroscopic treatment of posterior instability, which reports success rates that range from 75% to 91%. Longer-term follow-up will be needed to determine the natural history and prognosis or batter’s shoulder. Based on initial results, the authors predict good to excellent results for most players with batter’s shoulder who undergo proper treatment. Additionally, with the exception of switch hitters, the nonthrowing arm is affected. This can also improve the athlete’s return to play. Copyright © 2013 Elsevier Inc. All rights reserved.

  7. Treatment rationale of fractured posterior teeth.

    PubMed

    Silvestri, A R; Singh, I

    1978-11-01

    The four types of fractures most frequently encountered in posterior teeth--obliquely directed complete fractures, vertically directed complete fractures, obliquely directed incomplete fractures, and vertically directed incomplete fractures--have been described. A detailed treatment approach for each type has been presented.

  8. Posterior cingulate epilepsy: clinical and neurophysiological analysis.

    PubMed

    Enatsu, Rei; Bulacio, Juan; Nair, Dileep R; Bingaman, William; Najm, Imad; Gonzalez-Martinez, Jorge

    2014-01-01

    Posterior cingulate epilepsy (PCE) is misleading because the seizure onset is located in an anatomically deep and semiologically silent area. This type of epilepsy is rare and has not been well described yet. Knowledge of the characteristics of PCE is important for the interpretation of presurgical evaluation and better surgical strategy. The purpose of this study was to better characterise the clinical and neurophysiological features of PCE. This retrospective analysis included seven intractable PCE patients. Six patients had postcingulate ictal onset identified by stereotactic EEG (SEEG) evaluations. One patient had a postcingulate tumour. We analysed clinical semiology, the scalp EEG/SEEG findings and cortico-cortical evoked potential (CCEP). The classifications of scalp EEG were various, including non-localisible, lateralised to the seizure onset side, regional parieto-occipital, regional frontocentral and regional temporal. Three of seven patients showed motor manifestations, including bilateral asymmetric tonic seizures and hypermotor seizures. In these patients, ictal activities spread to frontal (lateral premotor area, orbitofrontal cortex, supplementary motor area, anteior cingulate gyrus) and parietal (precuneus, posterior cingulate gyrus, inferior parietal lobule (IPL), postcentral gyrus) areas. Four patients showed dialeptic seizures or automotor seizures, with seizure spread to medial temporal or IPL areas. CCEP was performed in four patients, suggesting electrophysiological connections from the posterior cingulate gyrus to parietal, temporal, mesial occipital and mesial frontal areas. This study revealed that the network from the posterior cingulate gyrus and the semiology of PCE (motor manifestation vs dialeptic/automotor seizure) varies depending upon the seizure spread patterns.

  9. Subspecialization in the human posterior medial cortex

    PubMed Central

    Bzdok, Danilo; Heeger, Adrian; Langner, Robert; Laird, Angela R.; Fox, Peter T.; Palomero-Gallagher, Nicola; Vogt, Brent A.; Zilles, Karl; Eickhoff, Simon B.

    2014-01-01

    The posterior medial cortex (PMC) is particularly poorly understood. Its neural activity changes have been related to highly disparate mental processes. We therefore investigated PMC properties with a data-driven exploratory approach. First, we subdivided the PMC by whole-brain coactivation profiles. Second, functional connectivity of the ensuing PMC regions was compared by task-constrained meta-analytic coactivation mapping (MACM) and task-unconstrained resting-state correlations (RSFC). Third, PMC regions were functionally described by forward/reverse functional inference. A precuneal cluster was mostly connected to the intraparietal sulcus, frontal eye fields, and right temporo-parietal junction; associated with attention and motor tasks. A ventral posterior cingulate cortex (PCC) cluster was mostly connected to the ventromedial prefrontal cortex and middle left inferior parietal cortex (IPC); associated with facial appraisal and language tasks. A dorsal PCC cluster was mostly connected to the dorsomedial prefrontal cortex, anterior/posterior IPC, posterior midcingulate cortex, and left dorsolateral prefrontal cortex; associated with delay discounting. A cluster in the retrosplenial cortex was mostly connected to the anterior thalamus and hippocampus. Furthermore, all PMC clusters were congruently coupled with the default mode network according to task-constrained but not task-unconstrained connectivity. We thus identified distinct regions in the PMC and characterized their neural networks and functional implications. PMID:25462801

  10. Subspecialization in the human posterior medial cortex.

    PubMed

    Bzdok, Danilo; Heeger, Adrian; Langner, Robert; Laird, Angela R; Fox, Peter T; Palomero-Gallagher, Nicola; Vogt, Brent A; Zilles, Karl; Eickhoff, Simon B

    2015-02-01

    The posterior medial cortex (PMC) is particularly poorly understood. Its neural activity changes have been related to highly disparate mental processes. We therefore investigated PMC properties with a data-driven exploratory approach. First, we subdivided the PMC by whole-brain coactivation profiles. Second, functional connectivity of the ensuing PMC regions was compared by task-constrained meta-analytic coactivation mapping (MACM) and task-unconstrained resting-state correlations (RSFC). Third, PMC regions were functionally described by forward/reverse functional inference. A precuneal cluster was mostly connected to the intraparietal sulcus, frontal eye fields, and right temporo-parietal junction; associated with attention and motor tasks. A ventral posterior cingulate cortex (PCC) cluster was mostly connected to the ventromedial prefrontal cortex and middle left inferior parietal cortex (IPC); associated with facial appraisal and language tasks. A dorsal PCC cluster was mostly connected to the dorsomedial prefrontal cortex, anterior/posterior IPC, posterior midcingulate cortex, and left dorsolateral prefrontal cortex; associated with delay discounting. A cluster in the retrosplenial cortex was mostly connected to the anterior thalamus and hippocampus. Furthermore, all PMC clusters were congruently coupled with the default mode network according to task-unconstrained but not task-constrained connectivity. We thus identified distinct regions in the PMC and characterized their neural networks and functional implications. Copyright © 2014 Elsevier Inc. All rights reserved.

  11. Posterior dislocation of the shoulder in athletes.

    PubMed

    Samilson, R L; Prieto, V

    1983-07-01

    Although posterior dislocation of the shoulder is a rare injury in athletes, failure to recognize and properly manage acute dislocation may have serious consequences. The article discusses the incidence, mechanism of injury, classification, pathologic findings, clinical and radiologic diagnosis, and management.

  12. Complicated posterior capsulorhexis: aetiology, management, and outcome

    PubMed Central

    Van Cauwenberge, F.; Rakic, J.; Galand, A.

    1997-01-01

    BACKGROUND—A 1 year retrospective analysis of 650 patients, who underwent a posterior capsulorhexis on their intact capsules, was performed to examine the incidence of complications, their aetiologies, and the outcome.
METHODS—Data were analysed on 32 patients with complicated capsulorhexis for type of surgery, preoperative and postoperative factors, and relative risk factors for vitreous issue.
RESULTS—There were six patients with vitreous loss. The posterior capsulorhexis was uncontrolled in 14 cases and difficult to perform in 12 cases. Implantation into the capsular bag was possible in all cases. Systemic vascular hazard and old age (over 80 years) were found to be statistically significant risk factors for vitreous loss (p=0.002 and p=0.03 respectively). The mean follow up was 13.5 months (range 4-25 months). One patient developed a retinal detachment and two had a transient clinical cystoid macular oedema. Visual acuity of ≥ 20/40 was obtained in 93% of the patients.
CONCLUSION—Loss of control of the posterior capsulorhexis has a low incidence but can lead to serious problems during surgery. A good knowledge of the technique is necessary to complete the procedure with a posterior capsulorhexis of the optimum size without vitreous loss.

 PMID:9135382

  13. BAER suppression during posterior fossa dural opening

    PubMed Central

    Shields, Christopher B.; Shields, Lisa B. E.; Jiang, Yi Dan; Yao, Tom; Zhang, Yi Ping; Sun, David A.

    2015-01-01

    Background: Intraoperative monitoring with brainstem auditory evoked responses (BAER) provides an early warning signal of potential neurological injury and may avert tissue damage to the auditory pathway or brainstem. Unexplained loss of the BAER signal in the operating room may present a dilemma to the neurosurgeon. Methods: This paper documents two patients who displayed a unique mechanism of suppression of the BAER apparent within minutes following dural opening for resection of a posterior fossa meningioma. Results: In two patients with anterior cerebellopontine angle and clival meningiomas, there was a significant deterioration of the BAER soon after durotomy but prior to cerebellar retraction and tumor removal. Intracranial structures in the posterior fossa lying between the tumor and dural opening were shifted posteriorly after durotomy. Conclusion: We hypothesized that the cochlear nerve and vessels entering the acoustic meatus were compressed or stretched when subjected to tissue shift. This movement caused cochlear nerve dysfunction that resulted in BAER suppression. BAER was partially restored after the tumor was decompressed, dura repaired, and bone replaced. BAER was not suppressed following durotomy for removal of a meningioma lying posterior to the cochlear complex. Insight into the mechanisms of durotomy-induced BAER inhibition would allay the neurosurgeon's anxiety during the operation. PMID:25883849

  14. [Condition of the posterior capsule in pseudophakia in children].

    PubMed

    Koraszewska-Matuszewska, B; Samochowiec-Donocik, E; Pieczara, E

    1995-01-01

    Evaluation of the posterior capsule transparency in children after congenital cataract surgery with posterior intraocular lens implantation. Examination comprised 41 eyes of 29 patients with posterior IOLS, aged 5-17 years (mean 10.3). In all cases, posterior capsule was unimpaired during surgery. During follow-up, (mean 27 months), 36.6% the eyes showed posterior capsule opacity of various degree. Neodymium YAG laser capsulotomy was performed in 13 cases and instrumental capsulotomy in 2. Opacity of the posterior capsule caused a decrease of visual acuity below 0.4. It improved after capsulotomy in all cases. No serious complications were observed.

  15. Hypertensive posterior reversible encephalopathy syndrome causing posterior fossa edema and hydrocephalus.

    PubMed

    Grossbach, Andrew J; Abel, Taylor J; Hodis, Brendan; Wassef, Shafik N; Greenlee, Jeremy D W

    2014-02-01

    Posterior reversible encephalopathy syndrome (PRES) is a well characterized entity resulting from the inability of cerebral autoregulation to adequately protect the brain from uncontrolled hypertension. It primarily affects the occipital lobes, but can also involve the structures in the posterior fossa including the brainstem and cerebellum. Treatment usually consists of strict blood pressure control, but more aggressive management may be indicated with acutely worsening neurological status. We present a patient with hypertensive encephalopathy that resulted in hydrocephalus and brainstem compression necessitating surgical decompression requiring ventriculostomy and suboccipital craniectomy. In rare cases, PRES can present with severe brainstem compression requiring emergent posterior fossa decompression. When brainstem signs are present on exam, emergent posterior fossa decompression may be safer than ventriculostomy alone. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. Oval capsulorhexis for phacoemulsification in posterior polar cataract with preexisting posterior capsule rupture.

    PubMed

    Singh, Kiranjit; Mittal, Vikas; Kaur, Harmit

    2011-07-01

    We describe use of an oval capsulorhexis rather than the conventional circular capsulorhexis for phacoemulsification in posterior polar cataract with preexisting posterior capsule rupture. An oval capsulorhexis minimizes the turbulence in the capsular bag by increasing the area available for efflux of fluid. It also enables end-to-end nuclear sculpting, removal of the nuclear fragment from the bag, intraocular lens (IOL) implantation, and vitrectomy without stretching the capsular bag. The smaller axis of the oval capsulorhexis facilitates optic capture of a sulcus-fixated IOL. The oval capsulorhexis can be used safely for phacoemulsification of all grades of nuclear sclerosis in posterior polar cataract with preexisting posterior capsule rupture. Copyright © 2011 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

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

    PubMed

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

    2017-01-01

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

  18. Fatal disseminated toxoplasmosis in a cardiac transplantation with seropositive match for Toxoplasma: should prophylaxis be extended?

    PubMed

    Castagnini, Marta; Bernazzali, Sonia; Ginanneschi, Chiara; Marchi, Bruna; Maccherini, Massimo; Tsioulpas, Charilaos; Tanganelli, Piero

    2007-11-01

    In cardiac transplant, toxoplasmosis in the immunocompromised recipient can result either from the transmission of the parasite from a seropositive donor (D+) to a seronegative recipient (R-) with the transplanted organ (more common) or from the reactivation of a pre-transplant latent infection (D-/R+ or D+/R+). In the immunocompromised patient, toxoplasmosis is a life-threatening disease. We report a case of disseminated toxoplasmosis following heart transplantation in a Toxoplasma seropositive recipient before transplantation (R+) (IgG 1:160, IgM negative) who received an organ from a Toxoplasma seropositive donor (D+) (IgG 1:640, IgM negative). No anti-Toxoplasma prophylactic treatment was administered. A number of complications arose in the postoperative period, as well as Enterobacter cloacae and Cytomegalovirus (CMV) (reactivation) infections, but neither serological nor histological toxoplasma recrudescence was evidenced. The patient died on post transplant day 41. Post-autopsy histological examinations revealed an unexpected diffuse toxoplasmosis (lungs, brain, heart).

  19. 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...

  20. Acid-fast lipids are important structural components of oocyst walls of Cryptosporidium, Toxoplasma, and Eimeria

    USDA-ARS?s Scientific Manuscript database

    Coccidia are protozoan parasites that cause significant human disease and are of major agricultural importance. Cryptosporidium spp.cause diarrhea in humans and animals, while congenital Toxoplasma infections causes blindness and death. Eimeria kills chickens, so all poultry feed contain antibioti...

  1. 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...

  2. 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.

  3. 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...

  4. Targeting Toxoplasma Tubules: Tubulin, Microtubules, and Associated Proteins in a Human Pathogen

    PubMed Central

    2014-01-01

    Toxoplasma gondii is an obligate intracellular parasite that causes serious opportunistic infections, birth defects, and blindness in humans. Microtubules are critically important components of diverse structures that are used throughout the Toxoplasma life cycle. As in other eukaryotes, spindle microtubules are required for chromosome segregation during replication. Additionally, a set of membrane-associated microtubules is essential for the elongated shape of invasive “zoites,” and motility follows a spiral trajectory that reflects the path of these microtubules. Toxoplasma zoites also construct an intricate, tubulin-based apical structure, termed the conoid, which is important for host cell invasion and associates with proteins typically found in the flagellar apparatus. Last, microgametes specifically construct a microtubule-containing flagellar axoneme in order to fertilize macrogametes, permitting genetic recombination. The specialized roles of these microtubule populations are mediated by distinct sets of associated proteins. This review summarizes our current understanding of the role of tubulin, microtubule populations, and associated proteins in Toxoplasma; these components are used for both novel and broadly conserved processes that are essential for parasite survival. PMID:25380753

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

    PubMed

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

    2013-06-01

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

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

    USDA-ARS?s Scientific Manuscript database

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

  7. Prevalence of Toxoplasma Infection in Mexican Newborns and Children: A Systematic Review from 1954 to 2009

    PubMed Central

    Galvan-Ramírez, Ma. de la Luz; Troyo-Sanroman, Rogelio; Roman, Sonia; Bernal-Redondo, Rosamaría; Vázquez Castellanos, José Luís

    2012-01-01

    Introduction. Recent studies in Mexico have shown that from 20/10,000 to 58/10,000 newborns with Toxoplasma infection could be undetected. The aim of this study was to determine the weighed prevalence of T. gondii infection and describe the epidemiological transition of infection in newborns. Methods. Research literature reporting Toxoplasma infection prevalence in Mexican newborns and children were searched in five international databases. Weighted prevalence was calculated by inverse variance-weighted method in asymptomatic and symptomatic study groups, and the epidemiological transition was estimated by a lineal regression analysis. Results. The weighed prevalence in 4833 asymptomatic newborns was 0.616%, CI95% (0.396%–0.835%) (P < 0.001), whereas, among 895 symptomatic newborns, the weighed prevalence was 3.02%, CI 95% (1.91%–4.1%) (P < 0.001). A downward trend of 0.25%/year represented an accumulated decrease of −13,75% in the prevalence in the symptomatic newborns throughout 55 years, whereas, in the asymptomatic children, the prevalence was similar over the course of the years. Conclusion. The high-weighted prevalence of congenital Toxoplasma infection in newborns justifies that Toxoplasma gondii testing be included in the screening programs for women during pregnancy and newborns in Mexico. A rapid diagnosis and treatment strategy could aid in limiting a potential damage to the newborns. PMID:23050161

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

    USDA-ARS?s Scientific Manuscript database

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

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

    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 pregna...

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

    PubMed

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

    2017-07-01

    We assessed Toxoplasma gondii seroprevalence in 53 free-ranging American black bears ( Ursus americanus ) in the Central Appalachian Mountains, US. Seroprevalence was 62% with no difference between males and females or between juvenile and adult bears. Wildlife agencies should consider warnings in hunter education programs to reduce the chances for human infection from this source.

  11. Prevalence to Toxoplasma gondii and Sarcocystis spp. In a reintroduced fisher (Martes pennanti) population in Pennsylvania

    USDA-ARS?s Scientific Manuscript database

    Understanding the role of disease in population regulation is important to the conservation of wildlife. We evaluated the prevalence of Toxoplasma gondii and Sarcocystis spp in 46 road-killed and accidental trapper-killed fisher carcasses collected by the Pennsylvania Game Commission and stored a...

  12. Development of granulomatous common variable immunodeficiency subsequent to infection with Toxoplasma gondii

    PubMed Central

    MRUSEK, S; MARX, A; KÜMMERLE-DESCHNER, J; TZARIBACHEV, N; ENDERS, A; RIEDE, U-N; WARNATZ, K; DANNECKER, G E; Ehl, S

    2004-01-01

    Common variable immunodeficiency (CVID) is a heterogeneous immunodeficiency that is accompanied by granulomatous lesions in 5–10% of cases. Why some patients develop granulomatous disease remains unclear. Here we describe a 12-year-old previously healthy girl who presented with pancytopenia and granulomatous lymphoproliferation subsequent to infection with Toxoplasma gondii. Loosely arranged non-fibrosing granulomas were observed in the liver, lymph nodes and lung, but no Toxoplasma tachyzoites could be demonstrated and polymerase chain reaction (PCR) and culture were negative for Toxoplasma and a wide range of other pathogens. While the patient had a normal peripheral B cell status at presentation, the development of CVID could be observed during the following months, leading to a loss of memory B cells. This was accompanied by an increasingly activated CD4+ T cell compartment and high serum levels of angiotensin-converting enzyme (ACE), tumour necrosis factor (TNF) and sCD25. Steroid therapy reduced pancytopenia, granulomatous lymphoproliferation and cytokine elevations, but did not improve the B cell status. This is the first report of an association of Toxoplasma infection with granulomatous CVID and provides one of the rare examples where the onset of CVID could be documented subsequent to an infectious disease. PMID:15320909

  13. 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 ...

  14. 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...

  15. 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 ...

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

    USDA-ARS?s Scientific Manuscript database

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

  17. 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...

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

    USDA-ARS?s Scientific Manuscript database

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

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

    USDA-ARS?s Scientific Manuscript database

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

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

    USDA-ARS?s Scientific Manuscript database

    Serum samples from 419 polar bears (Ursus maritimus) from Svalbard and the Barents Sea (collected 1990 - 2000) and 108 polar bears from East Greenland (collected 1999 - 2004) were assayed for antibodies against Toxoplasma gondii using the modified agglutination test (MAT). Antibody prevalences were ...

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

    USDA-ARS?s Scientific Manuscript database

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

  2. 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 ...

  3. Seroprevalence of Toxoplasma gondii among HIV Patients in Jahrom, Southern Iran.

    PubMed

    Rezanezhad, Hassan; Sayadi, Fateme; Shadmand, Enayatollah; Nasab, Seyed Dawood Mousavi; Yazdi, Hadi Rezaei; Solhjoo, Kavous; Kazemi, Akbar; Maleki, Monireh; Vasmehjani, Abbas Ahmadi

    2017-02-01

    Toxoplasma gondii is an important opportunistic agent especially in immunocompromised hosts and can cause significant morbidity and mortality. Hence, detection and monitoring of anti-Toxoplasma antibodies are of a great interest in HIV-infected patients. A study on the prevalence of toxoplasmosis and associated risk factors was carried out among HIV-infected patients in Jahrom, southern Iran. The prevalence of anti-Toxoplasma IgG antibodies was 21.1% in HIV-infected patients by ELISA. PCR was performed on all of the samples, and 1 of the blood samples was positively detected. Among the HIV patients, anti-Toxoplasma IgG antibodies were significantly higher in age group of 30-39 years old (P=0.05). The seroprevalence of toxoplasmosis in patients with CD4(+)<100 cells/μl was 33.3% that was significantly higher than the other groups (P=0.042) with or without IgG antibodies. The CD4(+) count mean of seropositive patients was lower than that of seronegative patients. The seroprevalence of toxoplasmosis in patients with highly active antiretroviral therapy was significantly less than patients without therapy (P=0.02). In conclusion, this study showed low seroprevalence of latent toxoplasmosis among HIV-infected patients in the region and confirmed the need for intensifying prevention efforts among this high-risk population and also the risk of toxoplasmosis reactivation which could be important among this population.

  4. 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...

  5. 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...

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

    USDA-ARS?s Scientific Manuscript database

    Background Leishmania infantum and Toxoplasma gondii are protozoa with zoonotic and economic importance. Prevalences of antibodies to these agents were assessed in 173 horses from the north of Portugal. Findings Antibodies to L. infantum were detected by the direct agglutination test (DAT); seven (...

  7. 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.

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

    PubMed Central

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

    1991-01-01

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

  9. 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 ...

  10. 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...

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

    USDA-ARS?s Scientific Manuscript database

    The aim of the present study was to investigate the prevalence of antibodies against Toxoplasma gondii in turkeys and chickens on family farms in the semi-arid region of the state of Pernambuco, Brazil. In order to do so, 204 sera samples from turkeys were analyzed using the Modified Agglutination T...

  12. 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...

  13. 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...

  14. 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...

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

    USDA-ARS?s Scientific Manuscript database

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

  16. 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...

  17. Prevalence of antibody to Toxoplasma gondii in black-headed gulls (Chroicocephalus ridibundus), Dianchi Lake, China.

    PubMed

    Miao, Qiang; Han, Jiang-qiang; Xiang, Xun; Yuan, Fei-Zhou; Liu, Yong-zhang; Duan, Gang; Zhu, Xing-quan; Zou, Feng-cai

    2014-07-01

    Sera from 659 Black-headed Gulls (Chroicocephalus ridibundus) in Dianchi Lake, China were assayed for Toxoplasma gondii antibodies using the modified agglutination test (MAT). Specific T. gondii antibodies were detected in 131 (19.9%) Black-headed Gulls (MAT titer ≥ 1 ∶ 5). These results indicate that T. gondii infection is common in Black-headed Gulls.

  18. 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...

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

    USDA-ARS?s Scientific Manuscript database

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

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

    USDA-ARS?s Scientific Manuscript database

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

  1. 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...

  2. 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...

  3. 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...

  4. Seroprevalence of Toxoplasma gondii from free-range chickens (Gallus domesticus) from Addis Adaba, Ethiopa

    USDA-ARS?s Scientific Manuscript database

    Prevalence of Toxoplasma gondii in free-range chickens (Gallus domesticus) is a good indicator of the environmental contamination with oocysts because chickens become infected mainly by feeding from ground/feed/soil contaminated with oocysts. The seroprevalence of T. gondii antibodies in 125 free-r...

  5. Toxoplasma gondii infections in chickens (Gallus domesticus): Prevalence, clinical disease, diagnosis, and public health significance

    USDA-ARS?s Scientific Manuscript database

    Chickens are considered one of the most important hosts in the epidemiology of Toxoplasma gondii infection because they are an efficient source of infection for cats that excrete the environmentally-resistant oocysts and because humans may become infected with this parasite after eating undercooked ...

  6. Geographical patterns of Toxoplasma gondii genetic diversity revealed by multilocus PCR-RFLP genotyping

    USDA-ARS?s Scientific Manuscript database

    In recent years, an extensive collection of Toxoplasma gondii samples have been typed by the multilocus PCR-RFLP method using a standardized set of 10 genetic markers. Here we summarize the data reported until the end of 2012. A total of 1457 samples were typed into 189 genotypes. Overall, only a fe...

  7. Prevalence of toxoplasma infection in Mexican newborns and children: a systematic review from 1954 to 2009.

    PubMed

    Galvan-Ramírez, Ma de la Luz; Troyo-Sanroman, Rogelio; Roman, Sonia; Bernal-Redondo, Rosamaría; Vázquez Castellanos, José Luís

    2012-01-01

    Introduction. Recent studies in Mexico have shown that from 20/10,000 to 58/10,000 newborns with Toxoplasma infection could be undetected. The aim of this study was to determine the weighed prevalence of T. gondii infection and describe the epidemiological transition of infection in newborns. Methods. Research literature reporting Toxoplasma infection prevalence in Mexican newborns and children were searched in five international databases. Weighted prevalence was calculated by inverse variance-weighted method in asymptomatic and symptomatic study groups, and the epidemiological transition was estimated by a lineal regression analysis. Results. The weighed prevalence in 4833 asymptomatic newborns was 0.616%, CI95% (0.396%-0.835%) (P < 0.001), whereas, among 895 symptomatic newborns, the weighed prevalence was 3.02%, CI 95% (1.91%-4.1%) (P < 0.001). A downward trend of 0.25%/year represented an accumulated decrease of -13,75% in the prevalence in the symptomatic newborns throughout 55 years, whereas, in the asymptomatic children, the prevalence was similar over the course of the years. Conclusion. The high-weighted prevalence of congenital Toxoplasma infection in newborns justifies that Toxoplasma gondii testing be included in the screening programs for women during pregnancy and newborns in Mexico. A rapid diagnosis and treatment strategy could aid in limiting a potential damage to the newborns.

  8. Evaluation of a Strategy for Toxoplasma gondii Oocyst Detection in Water

    PubMed Central

    Villena, Isabelle; Aubert, Dominique; Gomis, Philippe; Ferté, Hubert; Inglard, Jean-Christophe; Denis-Bisiaux, Hélène; Dondon, Julie-Muriel; Pisano, Eric; Ortis, Naïma; Pinon, Jean-Michel

    2004-01-01

    Several recent outbreaks of toxoplasmosis were related to drinking water. We propose a strategy for Toxoplasma oocyst detection as part of an approach to detecting multiple waterborne parasites, including Giardia and Cryptosporidium spp., by the U.S. Environmental Protection Agency method with the same sample. Water samples are filtered to recover Toxoplasma oocysts and purified on a sucrose density gradient. Detection is based on PCR and mouse inoculation (bioassay) to determine the presence and infectivity of recovered oocysts. In an experimental seeding assay with 100 liters of deionized water, a parasite density of 1 oocyst/liter was successfully detected by PCR in 60% of cases and a density of 10 oocysts/liter was detected in 100% of cases. The sensitivity of the PCR assay varied from less than 10 to more than 1000 oocysts/liter, depending on the sample source. PCR was always more sensitive than mouse inoculation. This detection strategy was then applied to 139 environmental water samples collected over a 20-month period. Fifty-three samples contained PCR inhibitors, which were overcome in 39 cases by bovine serum albumin addition. Among 125 interpretable samples, we detected Toxoplasma DNA in 10 cases (8%). None of the samples were positive by mouse inoculation. This strategy efficiently detects Toxoplasma oocysts in water and may be suitable as a public health sentinel method. PMID:15240280

  9. 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...

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

    USDA-ARS?s Scientific Manuscript database

    Prevalence of antibodies to Toxoplasma gondii was investigated in 673 domestic dogs from northeastern Portugal, by using the modified agglutination test (MAT) with 1:20 as cut-off for seropositivity; antibodies were found in 256 dogs (38.0%). Differences between seroprevalence levels in males (36.7%...

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

    USDA-ARS?s Scientific Manuscript database

    Little is known of the genetic diversity of Toxoplasma gondii circulating in wildlife. Available data indicate a predominance of one T. gondii genotype (haplogroup 12) in wildlife in the USA but it is uncertain if this is due to sampling bias, range of hosts, or geographical restriction. In the pres...

  12. 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...

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

    USDA-ARS?s Scientific Manuscript database

    Toxoplasmosis is a worldwide zoonosis. The ingestion of uncooked/undercooked meat and consumption of water contaminated with Toxoplasma gondii oocysts excreted by felids are the main modes of transmission of this parasite. Thousands of wild cervids are hunted or killed in traffic accidents yearly bu...

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

    USDA-ARS?s Scientific Manuscript database

    Kennel dogs can serve as sentinels and/or reservoirs of diseases of veterinary and zoonotic interest because they have often roamed free and lived outdoors, being exposed to pathogens. We tested for evidence of infection with three protozoans, Leishmania infantum, Toxoplasma gondii and Neospora cani...

  15. 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...

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

    USDA-ARS?s Scientific Manuscript database

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

  17. A parafusin-related Toxoplasma protein in Ca2+-regulated secretory organelles.

    PubMed

    Matthiesen, S H; Shenoy, S M; Kim, K; Singer, R H; Satir, B H

    2001-12-01

    We cloned a gene, PRPI, of Toxoplasma gondii encoding a 637-amino-acids protein having a calculated mass of 70 kDa. The sequence showed high homology to parafusin, a protein that in Paramecium tetraurelia participates in Ca2+-regulated exocytosis and is a paralog of phosphoglucomutase. We show that Toxoplasma gondii homogenate and an expressed recombinant PRP1 fusion protein cross-react with a specific peptide-derived antibody to parafusin in Western blots. Antibodies to the recombinant PRP1 showed cross-reaction with parafusin and recognized PRP1, as bands at M, 63 x 10(3) and 68 x 10(3), respectively. PRP1 is labeled when Toxoplasma gondii cells are incubated with inorganic 32P and appears as the major band on autoradiograms of SDS-PAGE gels. The localization of PRP1 was examined in secretory organelles of Toxoplasma gondii by deconvolution light microscopy followed by three dimensional reconstruction using pairwise combinations of specific antibodies. PRP1 localized to the apical third of the cell. It co-localized with micronemes, the only secretory organelle the secretion of which is Ca2+ dependent. Quantification of the co-localized stain suggests that only mature micronemes ready for exocytosis have PRP1. These findings suggest that PRP1, parafusin and other members of the phosphoglucomutase superfamily have a conserved role in Ca2+-regulated exocytic processes.

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

    USDA-ARS?s Scientific Manuscript database

    Seroprevalence of Toxoplasma gondii infection and associated risk factors were investigated in 401 women of childbearing age from the North of Portugal. Among the 98 (24.4%) seropositive women, 92 (93.9%) were detected as positive only for imunoglobulin (Ig) G, two women (2.0%) were positive only fo...

  19. Zidovudine antagonizes the action of pyrimethamine in experimental infection with Toxoplasma gondii.

    PubMed Central

    Israelski, D M; Tom, C; Remington, J S

    1989-01-01

    The effect of zidovudine (azidothymidine; AZT) on the action of pyrimethamine against Toxoplasma gondii was investigated. Zidovudine was found to antagonize the toxoplasmacidal effect of low concentrations of pyrimethamine in vitro, and in vitro synergism of pyrimethamine and sulfadiazine against T. gondii was reversed by zidovudine. Zidovudine also antagonized the therapeutic effect of pyrimethamine in mice acutely infected with T. gondii. Images PMID:2712547

  20. 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...

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

    USDA-ARS?s Scientific Manuscript database

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

  2. Statistical evaluation of test accuracy studies for Toxoplasma gondii in food animal intermediate hosts

    USDA-ARS?s Scientific Manuscript database

    The availability of accurate diagnostic tests is essential for the detection and control of Toxoplasma gondii infections in both definitive and intermediate hosts. Sensitivity, specificity and the area under the receiver-operating characteristic (ROC) curve are commonly-used measures of test accura...

  3. 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...

  4. A SAS-6-like protein suggests that the Toxoplasma conoid complex evolved from flagellar components.

    PubMed

    de Leon, Jessica Cruz; Scheumann, Nicole; Beatty, Wandy; Beck, Josh R; Tran, Johnson Q; Yau, Candace; Bradley, Peter J; Gull, Keith; Wickstead, Bill; Morrissette, Naomi S

    2013-07-01

    SAS-6 is required for centriole biogenesis in diverse eukaryotes. Here, we describe a novel family of SAS-6-like (SAS6L) proteins that share an N-terminal domain with SAS-6 but lack coiled-coil tails. SAS6L proteins are found in a subset of eukaryotes that contain SAS-6, including diverse protozoa and green algae. In the apicomplexan parasite Toxoplasma gondii, SAS-6 localizes to the centriole but SAS6L is found above the conoid, an enigmatic tubulin-containing structure found at the apex of a subset of alveolate organisms. Loss of SAS6L causes reduced fitness in Toxoplasma. The Trypanosoma brucei homolog of SAS6L localizes to the basal-plate region, the site in the axoneme where the central-pair microtubules are nucleated. When endogenous SAS6L is overexpressed in Toxoplasma tachyzoites or Trypanosoma trypomastigotes, it forms prominent filaments that extend through the cell cytoplasm, indicating that it retains a capacity to form higher-order structures despite lacking a coiled-coil domain. We conclude that although SAS6L proteins share a conserved domain with SAS-6, they are a functionally distinct family that predates the last common ancestor of eukaryotes. Moreover, the distinct localization of the SAS6L protein in Trypanosoma and Toxoplasma adds weight to the hypothesis that the conoid complex evolved from flagellar components.

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

    USDA-ARS?s Scientific Manuscript database

    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 ...

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

    PubMed

    Şuteu, Ovidiu; Mihalca, Andrei Daniel; Paştiu, Anamaria Ioana; Györke, Adriana; Matei, Ioana Adriana; Ionică, Angela; Balea, Anamaria; Oltean, Miruna; D'Amico, Gianluca; Sikó, Sándor Barabási; Ionescu, Dan; Gherman, Călin Mircea; Cozma, Vasile

    2014-07-01

    Brain samples from 182 red foxes (Vulpes vulpes) from Romania were examined using a standard PCR technique. Results provide evidence of Toxoplasma gondii (11 foxes=6.0%) and Neospora caninum (1 fox=0.5%) DNA in red foxes from Romania. No coinfections were found.

  7. Induction of Autophagy interferes the tachyzoite to bradyzoite transformation of Toxoplasma gondii.

    PubMed

    Li, Xiangzhi; Chen, Di; Hua, Qianqian; Wan, Yujing; Zheng, Lina; Liu, Yangyang; Lin, Jiaxin; Pan, Changwang; Hu, Xin; Tan, Feng

    2016-04-01

    Autophagy process in Toxoplasma gondii plays a vital role in regulating parasite survival or death. Thus, once having an understanding of certain effects of autophagy on the transformation of tachyzoite to bradyzoite this will allow us to elucidate the function of autophagy during parasite development. Herein, we used three TgAtg proteins involved in Atg8 conjugation system, TgAtg3, TgAtg7 and TgAtg8 to evaluate the autophagy level in tachyzoite and bradyzoite of Toxoplasma in vitro based on Pru TgAtg7-HA transgenic strains. We showed that both TgAtg3 and TgAtg8 were expressed at a significantly lower level in bradyzoites than in tachyzoites. Importantly, the number of parasites containing fluorescence-labelled TgAtg8 puncta was significantly reduced in bradyzoites than in tachyzoites, suggesting that autophagy is downregulated in Toxoplasma bradyzoite in vitro. Moreover, after treatment with drugs, bradyzoite-specific gene BAG1 levels decreased significantly in rapamycin-treated bradyzoites and increased significantly in 3-MA-treated bradyzoites in comparison with control bradyzoites, indicating that Toxoplasma autophagy is involved in the transformation of tachyzoite to bradyzoite in vitro. Together, it is suggested that autophagy may serve as a potential strategy to regulate the transformation.

  8. Establishment of replacement International Standard 13/132 for human antibodies to Toxoplasma gondii.

    PubMed

    Rijpkema, Sjoerd; Hockley, Jason; Rigsby, Peter; Guy, Edward C

    2016-09-01

    Sixteen laboratories carried out a collaborative study to validate 13/132 as a replacement International Standard (IS) for TOXM (3rd IS for anti-Toxoplasma Serum, Human, 1000 IU). 13/132 is a freeze dried preparation of pooled human plasma from six donors who experienced a recent Toxoplasma gondii infection. The potency of 13/132 was compared to TOXM and 01/600 (1st IS for anti-Toxoplasma IgG, Human, 20 IU). Samples were tested for IgA, IgG, IgG avidity and IgM in agglutination assays; enzyme linked immunosorbent assays (ELISA), enzyme linked fluorescent assays, immunoblots, immunofluorescence assays and the Sabin-Feldman dye test for Ig. 13/132 was strongly positive for Ig, IgA, IgG and IgM and the reproducibility was very good. 13/132 contains high levels of anti-Toxoplasma Ig, IgG and IgM and its potency falls between TOXM and 01/600. The avidity of IgG was found to be low, similar to the avidity of IgG from TOXM. 13/132 was established by the Expert Committee on Biological Standardization as the 4th IS for Antibodies, Human, to T. gondii with an assigned unitage of 160 IU per ampoule for Ig by dye test and 263 U per ampoule for IgG by ELISA.

  9. Targeting Toxoplasma tubules: tubulin, microtubules, and associated proteins in a human pathogen.

    PubMed

    Morrissette, Naomi

    2015-01-01

    Toxoplasma gondii is an obligate intracellular parasite that causes serious opportunistic infections, birth defects, and blindness in humans. Microtubules are critically important components of diverse structures that are used throughout the Toxoplasma life cycle. As in other eukaryotes, spindle microtubules are required for chromosome segregation during replication. Additionally, a set of membrane-associated microtubules is essential for the elongated shape of invasive "zoites," and motility follows a spiral trajectory that reflects the path of these microtubules. Toxoplasma zoites also construct an intricate, tubulin-based apical structure, termed the conoid, which is important for host cell invasion and associates with proteins typically found in the flagellar apparatus. Last, microgametes specifically construct a microtubule-containing flagellar axoneme in order to fertilize macrogametes, permitting genetic recombination. The specialized roles of these microtubule populations are mediated by distinct sets of associated proteins. This review summarizes our current understanding of the role of tubulin, microtubule populations, and associated proteins in Toxoplasma; these components are used for both novel and broadly conserved processes that are essential for parasite survival.

  10. Occurrence of antibodies to Toxoplasma gondii in the scavenging black vultures (Coragyps atratus) from Brazil

    USDA-ARS?s Scientific Manuscript database

    This is the first report of Toxoplasma gondii infection in black vultures (Coragyps atratus) that are are obligate scavenging birds found throughout the American continent. Serum samples from 121 wild black vultures captured in urban areas of the city of São Paulo, SP, Brazil, were tested for the pr...

  11. Seroprevalence of Toxoplasma gondii among HIV Patients in Jahrom, Southern Iran

    PubMed Central

    Rezanezhad, Hassan; Sayadi, Fateme; Shadmand, Enayatollah; Nasab, Seyed Dawood Mousavi; Yazdi, Hadi Rezaei; Solhjoo, Kavous; Kazemi, Akbar; Maleki, Monireh; Vasmehjani, Abbas Ahmadi

    2017-01-01

    Toxoplasma gondii is an important opportunistic agent especially in immunocompromised hosts and can cause significant morbidity and mortality. Hence, detection and monitoring of anti-Toxoplasma antibodies are of a great interest in HIV-infected patients. A study on the prevalence of toxoplasmosis and associated risk factors was carried out among HIV-infected patients in Jahrom, southern Iran. The prevalence of anti-Toxoplasma IgG antibodies was 21.1% in HIV-infected patients by ELISA. PCR was performed on all of the samples, and 1 of the blood samples was positively detected. Among the HIV patients, anti-Toxoplasma IgG antibodies were significantly higher in age group of 30–39 years old (P=0.05). The seroprevalence of toxoplasmosis in patients with CD4+<100 cells/μl was 33.3% that was significantly higher than the other groups (P=0.042) with or without IgG antibodies. The CD4+ count mean of seropositive patients was lower than that of seronegative patients. The seroprevalence of toxoplasmosis in patients with highly active antiretroviral therapy was significantly less than patients without therapy (P=0.02). In conclusion, this study showed low seroprevalence of latent toxoplasmosis among HIV-infected patients in the region and confirmed the need for intensifying prevention efforts among this high-risk population and also the risk of toxoplasmosis reactivation which could be important among this population. PMID:28285515

  12. Recent developments in drug discovery against the protozoal parasites Cryptosporidium and Toxoplasma.

    PubMed

    Chellan, Prinessa; Sadler, Peter J; Land, Kirkwood M

    2017-04-01

    Apicomplexan parasites cause some of the most devastating human diseases, including malaria, toxoplasmosis, and cryptosporidiosis. New drug discovery is imperative in light of increased resistance. In this digest article, we briefly explore some of the recent and promising developments in new drug discovery against two apicomplexan parasites, Cryptosporidium and Toxoplasma.

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

    EPA Science Inventory

    Toxoplasma gondii is a ubiquitous parasitic protozoan known to cause disease and death in warm-blooded animals. Bottlenose dolphins, walruses, sea otters, and other marine animals worldwide have died from toxoplasmosis, but the source of this parasite in the marine environment h...

  14. 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...

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

    USDA-ARS?s Scientific Manuscript database

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

  16. Detection of antibodies against Sarcocystis neurona, neospora spp., and Toxoplasma gondii in horses from Costa Rica

    USDA-ARS?s Scientific Manuscript database

    Serum samples from 315 horses from Costa Rica, Central America were examined for the presence of antibodies against Sarcocystis neurona, Neospora spp., and Toxoplasma gondii using the SnSAG2 ELISA, the NhSAG1 ELISA, and the modified agglutination test, respectively. Anti-S. neurona antibodies were f...

  17. 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.

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

    USDA-ARS?s Scientific Manuscript database

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

  19. Toxoplasma gondii infections in red-tailed hawks inoculated orally with tissue cysts.

    PubMed

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

    1991-04-01

    The response to inoculation of Toxoplasma gondii tissue cysts was examined in 3 red-tailed hawks (Buteo jamaicensis). One hawk (hawk 1) was inoculated orally with 3.000 tissue cysts of the GT-1 isolate of T. gondii and 2 hawks (hawks 2 and 3) each were inoculated orally with 12,000 tissue cysts of a mixture of 8 isolates of T. gondii. None of the hawks developed clinical signs of toxoplasmosis. Serum antibodies were measured with the modified direct agglutination test using formalin-fixed tachyzoites. Hawk 1 had a titer of 1:40 prior to inoculation and did not have an increase in titer during the study. Hawks 2 and 3 had titers of 1:5 and 1:10, respectively, prior to inoculation, and both had increased titers (titers greater than or equal to 1:60) by 1 wk postinoculation and remained T. gondii antibody positive throughout the 10 wk of the study. Toxoplasma gondii was isolated from the heart and breast muscle of hawk 1. The biologic behavior of this T. gondii isolate was different from the 1 inoculated, and it probably represents a prior natural infection. Toxoplasma gondii was isolated from the brain, heart, breast muscle, and a mixture of gizzard and proventriculus from hawk 2 and from breast muscle of hawk 3. Toxoplasma gondii was not isolated from the eye, lung, liver, kidney, or spleen of any red-tailed hawk.

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

    USDA-ARS?s Scientific Manuscript database

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

  1. 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...

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

    USDA-ARS?s Scientific Manuscript database

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

  3. 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...

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

    PubMed Central

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

    2006-01-01

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

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

    USDA-ARS?s Scientific Manuscript database

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

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

    USDA-ARS?s Scientific Manuscript database

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

  7. Garcinol Inhibits GCN5-Mediated Lysine Acetyltransferase Activity and Prevents Replication of the Parasite Toxoplasma gondii

    PubMed Central

    Jeffers, Victoria; Gao, Hongyu; Checkley, Lisa A.; Liu, Yunlong; Ferdig, Michael T.

    2016-01-01

    Lysine acetylation is a critical posttranslational modification that influences protein activity, stability, and binding properties. The acetylation of histone proteins in particular is a well-characterized feature of gene expression regulation. In the protozoan parasite Toxoplasma gondii, a number of lysine acetyltransferases (KATs) contribute to gene expression and are essential for parasite viability. The natural product garcinol was recently reported to inhibit enzymatic activities of GCN5 and p300 family KATs in other species. Here we show that garcinol inhibits TgGCN5b, the only nuclear GCN5 family KAT known to be required for Toxoplasma tachyzoite replication. Treatment of tachyzoites with garcinol led to a reduction of global lysine acetylation, particularly on histone H3 and TgGCN5b itself. We also performed transcriptome sequencing (RNA-seq), which revealed increasing aberrant gene expression coincident with increasing concentrations of garcinol. The majority of the genes that were most significantly affected by garcinol were also associated with TgGCN5b in a previously reported chromatin immunoprecipitation assay with microarray technology (ChIP-chip) analysis. The dysregulated gene expression induced by garcinol significantly inhibits Toxoplasma tachyzoite replication, and the concentrations used exhibit no overt toxicity on human host cells. Garcinol also inhibits Plasmodium falciparum asexual replication with a 50% inhibitory concentration (IC50) similar to that for Toxoplasma. Together, these data support that pharmacological inhibition of TgGCN5b leads to a catastrophic failure in gene expression control that prevents parasite replication. PMID:26810649

  8. 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...

  9. The standardization of 5 immunoassays for anti-Toxoplasma immunoglobulin G(IgG).

    PubMed

    Zhang, Kuo; Lin, Guigao; Han, Yanxi; Li, Jinming

    2017-09-01

    Quantitative immunoassays to detect IgG antibodies are the most commonly used tests for diagnosing toxoplasmosis. We investigated the current state of standardization of quantitative immunoassays used to measure anti-Toxoplasma IgG levels. Four fully automated immunoassays (Architect i4000ISR, Immulite 2000 Xpi, Siemens; Liaison, DiaSorin; Cobas e601, Roche) and one manual immunoassay (ELISA classic Toxo IgG, Virion Serion) were performed on the following: individual patient serum samples, the WHO international standards, control samples, and calibrators provided by 5 immunoassay manufacturers. Statistical analysis was used to illustrate the results. No perfect correlation (slope=1.0) was found between any 2 assays. Large differences in anti-Toxoplasma IgG titers were observed among the 5 immunoassays using serum samples from individual patients. Using IS 01/600 as a calibrator minimized the inter-assay variability of anti-Toxoplasma IgG values CONCLUSIONS: There is still significant effort needed towards standardization of anti-Toxoplasma IgG quantitative immunoassays. Copyright © 2017 Elsevier B.V. All rights reserved.

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

    USDA-ARS?s Scientific Manuscript database

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

  11. 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...

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

    PubMed Central

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

    2015-01-01

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

  13. 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 ...

  14. 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...

  15. 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...

  16. 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...

  17. 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 ...

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

    USDA-ARS?s Scientific Manuscript database

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

  19. Neurons are the Primary Target Cell for the Brain-Tropic Intracellular Parasite Toxoplasma gondii

    PubMed Central

    Dietrich, Hans K.; Nguyen, Elizabeth; MacDonald, Wes R.; Trivedi, Tapasya; Devineni, Asha; Koshy, Anita A.

    2016-01-01

    Toxoplasma gondii, a common brain-tropic parasite, is capable of infecting most nucleated cells, including astrocytes and neurons, in vitro. Yet, in vivo, Toxoplasma is primarily found in neurons. In vitro data showing that interferon-γ-stimulated astrocytes, but not neurons, clear intracellular parasites suggest that neurons alone are persistently infected in vivo because they lack the ability to clear intracellular parasites. Here we test this theory by using a novel Toxoplasma-mouse model capable of marking and tracking host cells that directly interact with parasites, even if the interaction is transient. Remarkably, we find that Toxoplasma shows a strong predilection for interacting with neurons throughout CNS infection. This predilection remains in the setting of IFN-γ depletion; infection with parasites resistant to the major mechanism by which murine astrocytes clear parasites; or when directly injecting parasites into the brain. These findings, in combination with prior work, strongly suggest that neurons are not incidentally infected, but rather they are Toxoplasma’s primary in vivo target. PMID:26895155

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

    USDA-ARS?s Scientific Manuscript database

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