Toxoplasma gondii und Plasmodium Spezies sind obligat intrazelluläre Parasiten, die Zucker zur Energiehomöostase als auch für die Synthese lebenswichtiger Makromoleküle verwenden. Die hier vorgestellten Daten zeigen, dass der Glukosetransporter von T. gondii, TgGT1, und die homologen Transporter von P. falciparum und P. berghei, PfHT1 und PbHT1, neben Glukose auch Mannose, Fructose und Galactose transportieren. Toxoplasma Tachyzoiten exprimieren neben TgGT1 noch einen weiteren putative Zuckertransporter (TgST2) an der Parasitenoberfläche. Beide Proteine sind nicht essentiell, wie durch ihre individuelle und gleichzeitige Gendeletion belegt wird. Die Deletion von TgGT1 bewirkt einen geringen Wachstumsdefekt. Die Mutante ?tggt1 zeigt keine Glukoseaufnahmeaktivität und folglich eine verminderte glukoseabhängige Motilität. In ?tggt1 Parasiten wird ein verstärkter Glutaminstoffwechsel nachgewiesen, der ausreichend ist dessen Motilität und Replikationsaktivität zu erhalten. Die ?tggt1 Mutante gewährt Einblick in die Anpassungsfähigkeit von T. gondii an unterschiedliche Wirtszellen. Im Gegensatz zu T. gondii benötigen erythrozytäre Plasmodien Glukose und der Transporter PfHT1 wird derzeit als drug-target eingestuft. Hier wird gezeigt, dass das PfHT1-Homolog, PbHT1, essentiell in Blutstadien des Nagerparasiten Plasmodium berghei ist, jedoch auch während des gesamten Lebenszyklus des Parasiten exprimiert wird. Ein PfHT1- und PbHT1-spezifischer Inhibitor (Compound 3361) kann die Entwicklung von P. berghei Leberstadien und Okineten stark hemmen. Um zukünftig PfHT1-Inhibitoren im Hochdurchsatzverfahren zu identifizieren und testen zu können, wurden auf Saccharomyces cerevisiae und P. berghei basierende Expressionssysteme für PfHT1 entwickelt. Abschließend stellt diese Arbeit die Unterschiedlichkeit des zentralen Kohlenstoffwechsels von Toxoplasma und Plasmodium Parasiten durch bisher unbekannter Aspekte heraus. / Toxoplasma gondii and Plasmodium species are obligate intracellular pathogens that utilize host sugars for energy homeostasis and macro molecular synthesis. Here, we report that the T. gondii glucose transporter, TgGT1, and of its homologs of P. falciparum and P. berghei (PfHT1 and PbHT1) transport glucose, mannose, galactose and fructose. Besides TgGT1, Toxoplasma harbours one additional surface localized putative sugar transporter (TgST2). Surprisingly both Proteins are nonessential and only the deletion of TgGT1 inflicts a mild defect in the parasite replication. The ?tggt1 mutant is unable to import glucose and consequently displays an attenuated glucose-dependent motility, which is completely rescued by glutamine. ?tggt1 performs increased glutamine metabolism that is sufficient to sustain motility and replication. The ?tggt1 strain provides a model for further investigating its adaptation to disparate host cells. In contrast to T. gondii, erythrocytic stages of Plasmodium species critically depend on glucose uptake, and the PfHT1 transporter is considered as a drug target against human malaria. Here, we report that PbHT1 (a PfHT1 homolog) is also essential for blood stage development in the rodent malaria parasite P. berghei. PbHT1 is expressed throughout the life cycle. Moreover, a PfHT1- and PbHT1-specific sugar analogue, compound 3361, can inhibit the hepatic development and ookinete formation in P. berghei. These results signify that PbHT1 and exogenous glucose are also required during the ex-erythrocytic stages of P. berghei. To permit a high-throughput screening of selective PfHT1 inhibitors and their subsequent in vivo assessment, we have established a PfHT1-expressing Saccharomyces cerevisiae mutant and generated a PfHT1-dependent ?pbht1 of P. berghei strain. This thesis underscores various previously unknown aspects of sugar metabolism in Toxoplasma and Plasmodium, and unravel their metabolic differences.

The relation between the intracellular parasite Toxoplasma gondii and schizophrenia was studied and confirmed in several studies. There are proofs that latent toxoplasmosis deteriorates the course of schizophrenia. The goal of this study was to clarify whether there are differences between subjectively perceived quality of life of infected and non-infected psychiatric patients. We tested men and women from the PCP treated for the diagnosis of schizophrenia, who undertook serology blood tests for detection of anamnestic T. gondii antibodies. Patients also filled out two questionaires that assessed subjectively perceived quality of life - SOS-10 and WHOQOL-BREF. Patients filled out these questionaires twice, both at the start of the study before coming to psychiatric therapeutical institution and after one year. During the first testing were the questionaires filled out by 171 persons, after one year by 108 persons. Based on the results of these tests we found out that latent toxoplasmosis had a negative impact on subjectively perceived quality of life of schizophrenia patients, particularly on infected women. On the other hand, the quality of life of non-infected patients improved during one year. The effect of toxoplasmosis on quality of life was gender related, which could be explained by already...

Resumo: O objetivo desta pesquisa foi avaliar um módulo de um programa de formação continuada semipresencial acerca da toxoplasmose para educadores. Para tanto, avaliamos as habilidades cognitivas de 165 profissionais de escolas municipais de educação infantil e fundamental nível I, antes e após a execução de um curso semipresencial online, no período de 2009 a 2013. Quanto ao nível de conhecimento geral sobre toxoplasmose, em todas as questões, observamos aumento significativo (p<0,0001), após o curso quando comparados com os dados iniciais. Em relação ao agente etiológico, entre 97% das pessoas que possuíam conhecimento insatisfatório antes da aplicação do curso, apenas 8% permaneceram (p<0,0001) no mesmo nível. Os sinais clínicos da toxoplasmose humana mais citados depois do curso, em ordem decrescente, foram: aborto e/ou problemas congênitos (60%) e linfadenopatia (53,9%), enquanto que em animais foram febre (29,1%) e aborto (26,7%). Os meios de transmissão mais citados pelos cursistas após a intervenção foram: o contato com fezes de gatos infectados contendo oocistos (51,5%) e, em seguida, em menor proporção, a ingestão de carnes cruas e mal cozidas (37,6%). Os meios de prevenção mais citados, após o curso, foram: evitar comer carnes cruas e mal cozidas (58,2%) e evitar o contato com fezes de animais (51,5%). Com base nos resultados obtidos nesta pesquisa, foi possível comprovar a contribuição positiva da formação continuada de docentes, por meio de recursos da Educação a Distância (EaD), para a aquisição de conhecimentos, fato inédito na literatura consultada. / Abstract:The aim of this research was to evaluate a module of a semipresential continuing education program for educators about toxoplasmosis. Therefore, we evaluated the cognitive skills of 165 professionals from public schools in kindergarten and elementary level I, before and after the implementation of a semipresential online course, from 2009 to 2013. As regards the general level of knowledge about toxoplasmosis in all issues, we observed a significant increase (p <0.0001) after the course compared with the initial data. Regarding the etiologic agent, between 97% of those who had a little knowledge before application of the course, only 8% remained (p <0.0001) at the same level. Clinical signs of human toxoplasmosis most cited after the course, in descending order, were: abortion and / or congenital problems (60%) and lymphadenopathy (53.9%), while in animals were fever (29.1%) and abortion (26.7%). The means of human transmission most often cited by the course participants after the intervention were: the contact with the feces of infected cats containing oocysts (51.5%) and then, the eating of raw and undercooked meat (37.6%). The most frequently mentioned means of prevention, after the course were: avoid to eat raw and undercooked meat (58.2%) and avoid the contact with animal feces (51.5%). Based on the results obtained in this study, it was possible to prove the contribution of continuing education of teachers by means of Distance Learning (EaD) for the acquisition of knowledge, unprecedented in the literature. / Orientador:Katia Denise Saraiva Bresciani / Banca:Jancarlo Ferreira Gomes / Banca:Adolarata Aparecida Bianco Carvalho / Banca:Carlos Noriyuki Kaneto / Banca: Luzia Helena Queiroz / Doutor

Submitted by Erika Demachki (erikademachki@gmail.com) on 2017-01-04T19:50:51Z No. of bitstreams: 2 Dissertação - Thaís Bandeira Riesco - 2016.pdf: 4442276 bytes, checksum: fac73acc016bbd502cb80be355adc09d (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2017-01-05T10:04:44Z (GMT) No. of bitstreams: 2 Dissertação - Thaís Bandeira Riesco - 2016.pdf: 4442276 bytes, checksum: fac73acc016bbd502cb80be355adc09d (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-01-05T10:04:44Z (GMT). No. of bitstreams: 2 Dissertação - Thaís Bandeira Riesco - 2016.pdf: 4442276 bytes, checksum: fac73acc016bbd502cb80be355adc09d (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2016-12-09 / Introduction: Toxoplasma gondii is the etiological agent of a parasitic parasitic disease of universal distribution, with infected individuals in all countries. The main forms of contagion are through the ingestion of different parasite evolutionary forms present in raw meats or undercooked, unfiltered water, unpasteurized milk, contaminated soil handling and contact with infected cats. Clinical disease is less frequent and the most severe forms can be found when congenital transmission occurs and in immunocompromised patients. When the fetus touches this infectious agent and survive, it can present several problems such as: restriction in the intrauterine growth, premature birth, microcephaly, hydrocephalus, brain calcifications, pneumonitis, hepatosplenomegaly, skin rash, intellectual disability, among others. The consequences to the fetus are higher in the first trimester of pregnancy and the transmissibility in the third trimester is the highest. The degree of commitment of the newborn will depend on the gestational period in the moment of the first transmission of the illness and the pregnant woman. Objective: The objectives of this study were to evaluate perceptible alterations in the neuropsychomotor examination and in anthropometric measures of newborns (RNs) of chronically infected mothers by Toxoplasma gondii. Methods: The study was performed in a population of 79 children of puerperal mothers, 41 of them were children of mother with infection of toxoplasmosis and 38 were children of not infected mother by the protozoan. It was made out a sociodemographic interview with these mothers through a questionnaire and an examination of primitive reflexes in their respective children. The study was conducted in one maternity of standard for risk pregnancy, in the city of Goiânia, Goiás, in the period from June 2015 to June 2016. The analysis were performed with the aid of the statistical package SPSS®, version 23. The serologic testing for confirmation of toxoplasmosis infection and absence of anti-T gondii in the mothers serum was made by Immunoassay of Microparticles by Chemiluminescense (CMIA). Results: Neuropsychomotor examination the absence of reflection escape the suffocation was found in two children of chronically infected mothers. In the comparison of the thoracic perimeter and the cephalic perimeter 31/79 children were classified as inadequate and two children of mothers chronically infected were too small for their gestational age. Conclusion: In relation to the neuropsychomotor examination and anthropometric measurements, in the group of newborn of puerperal mothers chronically infected by Toxoplasma gondii could not detect any perceptible alterations when in comparison to the control group of susceptible mothers. / Introdução: Toxoplasma gondii é o agente etiológico de uma parasitose de distribuição universal, com indivíduos infectados em todos os países. As principais formas de contágio são através da ingestão de diferentes formas evolutivas do parasito presentes em carnes cruas ou mal cozidas, água não filtrada, leite não pasteurizado, manipulação de terra contaminada e convívio com gatos infectados. A doença clínica é pouco freqüente e as formas mais graves podem ser encontradas quando ocorre a transmissão congênita e em pacientes imunocomprometidos. Quando o feto entra em contato com esse agente infeccioso e sobrevive pode apresentar inúmeros problemas como: restrição de crescimento intrauterino, nascimento prematuro, microcefalia, hidrocefalia, calcificações cerebrais, pneumonite, hepatoesplenomegalia, erupção cutânea, retardo mental, entre outros. As conseqüências para o feto são mais graves no primeiro trimestre de gestação, e a transmissibilidade no terceiro trimestre é mais elevada. O grau de comprometimento do recémnascido irá depender da fase em que a gestação se encontrava no momento do primeiro contágio da gestante com o parasito. Objetivos: Os objetivos deste estudo foram avaliar alterações perceptíveis no exame neuropsicomotor e nas medidas antropométricas de recém-nascidos (RNs) de mães cronicamente infectadas pelo Toxoplasma gondii. Métodos: A população do estudo foi composta por 79 filhos de puérperas, os quais 41 eram filhos de mães com toxoplasmose crônica e 38 filhos de mães não infectadas pelo protozoário. Foi realizada uma entrevista sociodemográfica com essas mães através de um questionário e um exame de reflexos primitivos em seus respectivos filhos. O estudo foi realizado em uma maternidade de referência para gestações de risco, na cidade de Goiânia, Goiás, no período de junho de 2015 a junho de 2016. As análises foram realizadas com o auxílio do pacote estatístico SPSS ®, versão 23. O teste sorológico para confirmação da toxoplasmose infecção e ausência de anticorpos anti-T gondii no soro das mães foi feito por Imunoensaio de Micropartículas por Quimioluminescência (CMIA). Resultados: No exame neuropsicomotor a ausência do reflexo de fuga ao sufocamento foi encontrada em duas crianças filhas de mães cronicamente infectadas. Na comparação entre perímetro torácico e perímetro cefálico 31/79 crianças foram classificadas como inadequadas e duas crianças de mães cronicamente infectadas estavam pequenas para a idade gestacional. Conclusão: Em relação ao exame neuropsicomotor e as medidas antropométricas no grupo de recém-nascidos filhos de puérperas cronicamente infectadas pelo Toxoplasma gondii não foi possível detectar alterações perceptíveis quando em comparação ao grupo controle de mães suscetíveis.

Determina la frecuencia de anticuerpos contra T. gondii en conejos mascota (Oryctolagus cuniculus) que llegaron como pacientes al Consultorio de Animales Silvestres y Exóticos de la Facultad de Medicina Veterinaria de la Universidad Nacional Mayor de San Marcos, en el distrito de San Borja, Lima, Perú; durante el periodo de Enero a Junio del año 2018. Además de establecer si existe una asociación entre los posibles factores de riesgo (sexo, edad, tipo de alimento y presencia de gatos) y la seropositividad de anticuerpos contra T. gondii. Se colectaron 89 muestras de sangre de conejos mediante punción de la vena safena lateral o de la vena yugular, de las cuales se obtuvieron los sueros para ser analizadas. Para el diagnóstico se utilizó la técnica de Hemaglutinación Indirecta (HAI), por lo que se prepararon diluciones hasta 1:1024 y se consideraron como positivas aquellos títulos ≥ a 1:64. Asimismo mediante el empleo de 2-Mercaptoetanol se buscó determinar si había infección aguda en aquellos animales seropositivos donde el patrón de aglutinación desaparece en dos títulos como mínimo. La frecuencia de anticuerpos contra T. gondii fue de 6.74%. Adicionalmente se entrevistó a los propietarios de los conejos para recopilar información sobre posibles factores asociados a la infección con T. gondii, clasificando éstos datos en edad (juvenil:<1año, adulto: 1-5años y geronte: >5años), sexo, tipo de alimento (pellet, fresco o ambos) y presencia de gatos. Se utilizó la prueba estadística de Chi cuadrado para encontrar asociación significativa entre los posibles factores de riesgo y la presencia de anticuerpos contra T. gondii. Se observó asociación significativa (p<0.05) entre la seropositividad y el tipo de alimento que consume el animal, así como la edad mientras que no se encontró asociación con el sexo, y presencia de gatos. / Tesis

Toxoplasma gondii infects approximately one third of the population worldwide. There is strong evidence that a relationship between T. gondii titer and depressive symptoms exists. There is also evidence suggesting a protective effect of RhD positive blood factor on toxoplasma-induced behavioral and personality changes. This protective effect may influence the relationship between T. gondii and prenatal depressive symptoms. The purpose of this secondary data analysis was to examine the possible protective effect of RhD positive blood factor on prenatal depressive symptoms in 56 pregnant women with T. gondii infection. The cross-sectional design was utilized to answer the question “Does positive RhD blood factor provide a protective effect on prenatal depressive symptoms of patients infected with T. gondii when controlling for ethnicity, race, income, marital status, age and stress?” The conceptual model hypothesized that there was a relationship between socio-demographic variables (age, income, marital status, race, and ethnicity), stress, positive T. gondii titers, RhD positive blood factor, and prenatal depressive symptoms. Pearson correlations and multiple regression were utilized to explore the aims of this study demonstrated in the four statistical models. Significant relationship between stress and positive T.gondii seropositivity on prenatal depressive symptoms was identified. There was no significant relationship identified between RhD positive blood factor on the pregnant women infected with T. gondii which could be attributed to the small sample size.

Ce travail a porté sur l'étude de la dynamique de la transmission d'un parasite à cycle complexe, Toxoplasma gondii, dans des milieux contrastés. Dans une première partie, la dynamique de la transmission du parasite est étudiée dans un site urbain abritant une population très dense de chats domestiques (Felis catus). Nos travaux permettent de poser l'hypothèse d'un cycle de transmission parasitaire simple lorsque les hôtes intermédiaires sont en densité très faible relativement à celle des chats. Par ailleurs, nous mettons en évidence l'existence de zones de contamination du sol par les oocystes de T. gondii, qui sont très localisées, et qui correspondent aux zones de défécation communes des chats. Dans une deuxième partie, la variabilité de la dynamique de transmission de T. gondii dans les milieux riches en hôtes intermédiaires est abordée. Nous mettons notamment en évidence des indicateurs de la variabilité interspécifique du niveau d'infection chez les hôtes intermédiaires (masse corporelle spécifique et habitat). Par ailleurs, nous montrons qu'il existe des relations entre la composition de l'environnement, la variabilité du climat, et le niveau d'infection de la toxoplasmose chez le chat domestique et le chat forestier (Felis silvestris). L'ensemble du travail montre l'intérêt d'une approche éco-épidémiologique dans la compréhension de la variabilité du cycle de T. gondii, notamment par l'utilisation du suivi à long terme de plusieurs populations de chats vivant dans différents environnements. Il ouvre la voie à différentes perspectives de recherche, tant sur le plan appliqué (amélioration de la détection d'oocystes) que sur un aspect de modélisation.

Les modifications d'histones chez T. gondii représentent un des mécanismes majeurs pour contrôler la transcription des gènes et l'acétylation de certaines histones est impliquée dans le phénomène de différenciation parasitaire qu'est l'interconversion. Nous avons utilisé un inhibiteur d'histones déacétylases, FR235222, comme outil afin de clarifier l'implication de l'acétylation des histones chez T. gondii. Le séquençage d'un mutant résistant à la FR235222 a permis d'identifier TgHDAC3 comme cible préférentielle de cet iHDAC. Le domaine d'interaction est spécifique de la famille des Apicomplexa ce qui explique la sélectivité de cette molécule pour T. gondii et d'autres Apicomplexes dont Plasmodium sp. Sur tachyzoïtes traités, FR235222 augmente le taux d'acétylation des histones de certains gènes dont 1/3 est spécifique des stades sporozoïtes ou bradyzoïtes avec une surexpression de ces gènes après traitement par FR235222. L'activité antiparasitaire de différents iHDAC a été testée parallèlement sur les deux stades importants en pathologie humaine: le tachyzoïte et le kyste. Sur le tachyzoïte, seuls les tétrapeptides cycliques présentent une forte activité antiparasitaire avec des EC50 d'environ 10 nM. Les kystes ex-vivo traités avec FR235222, sont non infectants: absence de toxoplasmose chez la souris ré-inoculée avec ces kystes. En conclusion, FR235222 présente une activité dirigée contre l'HDAC3 de T. gondii et une spécificité envers les Apicomplexes. En interférant avec le cycle naturel du parasite, cette molécule induit la mort des tachyzoïtes in vitro et supprime le pouvoir infectant des kystes in vivo. Ce travail ouvre une voie prometteuse dans la stratégie thérapeutique des pathologies à Apicomplexes.

Toxoplasma gondii, the causal agent of toxoplasmosis, is an important water and food borne protozoan parasite. T. gondii was previously shown to have a distinct clonal population structure composed of Type I, II and III lineages in North America and Europe. But more recent studies demonstrated high diversity in South America. In the present project we have conducted an intensive study of the population diversity of T. gondii and surveyed the extent of genetic variation among natural T. gondii isolates on a global scale in order to better understand the population dynamics and pathogenesis of this parasite. To this end, 948 T. gondii isolates have been collected from a broad range of animal hosts and different sites worldwide. Our initial multilocus PCR-RFLP genotyping analysis revealed high diversity (~140 distinct genotypes) with abundant unique genotypes in South America and a strong clonal population structure in North America, Europe, Asia and Africa. It also showed that the Type II is the most common lineage worldwide, followed by the type III strain. The Type I strain, though widely distributed, has been infrequently isolated. Several new clonal genotypes have been identified from South America. The newly identified 140 RFLP genotypes have been further analyzed by multilocus microsatellites and intron sequencing methods. The composite data set identified 11 different haplotypes, providing a framework for future study of molecular epidemiology and population genetics of T. gondii . Multilocus DNA sequencing of markers from each of the 14 chromosomes covering the entire genome has also been completed to help reveal more information about genome evolution and the origin of T. gondii . Taken together, this comprehensive epidemiological and population genetic study has revealed significant details on the diversity and extent of sexual recombination, which provides the basis for future studies to understand transmission patterns, population dynamics and origin of this successful apicomplexan parasite Toxoplasma gondii.

The increasing prevalence of apicomplexan parasites such as Plasmodium, Toxoplasma, and Cryptosporidium represents a significant global healthcare burden. Treatment options are increasingly limited due to the emergence of new resistant strains. We postulate that parasites have evolved distinct metabolic strategies critical for growth and survival during human infections, and therefore susceptible to drug targeting using a systematic approach. I developed iCS306, a fully characterized metabolic network reconstruction of the model organism Toxoplasma gondii via extensive curation of available genomic and biochemical data. Using available microarray data, metabolic constraints for six different clinical strains of Toxoplasma were modeled. I conducted various in silico experiments using flux balance analysis in order to identify essential metabolic processes, and to illustrate the differences in metabolic behaviour across Toxoplasma strains. The results elucidate probable explanations for the underlying mechanisms which account for the similarities and differences among strains of Toxoplasma, and among species of Apicomplexa.