Toxoplasma gondii infection induces cell apoptosis via multiple pathways revealed by transcriptome analysis / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Toxoplasma gondii is a worldwide parasite that can infect almost all kinds of mammals and cause fatal toxoplasmosis in immunocompromised patients. Apoptosis is one of the principal strategies of host cells to clear pathogens and maintain organismal homeostasis, but the mechanism of cell apoptosis induced by T. gondii remains obscure. To explore the apoptosis influenced by T. gondii, Vero cells infected or uninfected with the parasite were subjected to apoptosis detection and subsequent dual RNA sequencing (RNA-seq). Using high-throughput Illumina sequencing and bioinformatics analysis, we found that pro-apoptosis genes such as DNA damage-inducible transcript 3 (DDIT3), growth arrest and DNA damage-inducible α (GADD45A), caspase-3 (CASP3), and high-temperature requirement protease A2 (HtrA2) were upregulated, and anti-apoptosis genes such as poly(adenosine diphosphate (ADP)-ribose) polymerase family member 3 (PARP3), B-cell lymphoma 2 (Bcl-2), and baculoviral inhibitor of apoptosis protein (IAP) repeat containing 5 (BIRC5) were downregulated. Besides, tumor necrosis factor (TNF) receptor-associated factor 1 (TRAF1), TRAF2, TNF receptor superfamily member 10b (TNFRSF10b), disabled homolog 2 (DAB2)‍-interacting protein (DAB2IP), and inositol 1,4,5-trisphosphate receptor type 3 (ITPR3) were enriched in the upstream of TNF, TNF-related apoptosis-inducing ligand (TRAIL), and endoplasmic reticulum (ER) stress pathways, and TRAIL-receptor 2 (TRAIL-R2) was regarded as an important membrane receptor influenced by T. gondii that had not been previously considered. In conclusion, the T. gondii RH strain could promote and mediate apoptosis through multiple pathways mentioned above in Vero cells. Our findings improve the understanding of the T. gondii infection process through providing new insights into the related cellular apoptosis mechanisms.

Toxoplasma gondii infection damages the perineuronal nets in a murine model

BACKGROUND Behavioral and neurochemical alterations associated with toxoplasmosis may be influenced by the persistence of tissue cysts and activation of an immune response in the brain of Toxoplasma gondii-infected hosts. The cerebral extracellular matrix is organised as perineuronal nets (PNNs) that are both released and ensheath by some neurons and glial cells. There is evidences to suggest that PNNs impairment is a pathophysiological mechanism associated with neuropsychiatric conditions. However, there is a lack of information regarding the impact of parasitic infections on the PNNs integrity and how this could affect the host's behavior. OBJECTIVES In this context, we aimed to analyse the impact of T. gondii infection on cyst burden, PNNs integrity, and possible effects in the locomotor activity of chronically infected mice. METHODS We infected mice with T. gondii ME-49 strain. After thirty days, we assessed locomotor performance of animals using the open field test, followed by evaluation of cysts burden and PNNs integrity in four brain regions (primary and secondary motor cortices, prefrontal and somesthetic cortex) to assess the PNNs integrity using Wisteria floribunda agglutinin (WFA) labeling by immunohistochemical analyses. FINDINGS AND MAIN CONCLUSIONS Our findings revealed a random distribution of cysts in the brain, the disruption of PNNs surrounding neurons in four areas of the cerebral cortex and hyperlocomotor behavior in T. gondii-infected mice. These results can contribute to elucidate the link toxoplasmosis with the establishment of neuroinflammatory response in neuropsychiatric disorders and to raise a discussion about the mechanisms related to changes in brain connectivity, with possible behavioral repercussions during chronic T. gondii infection.

Disseminated toxoplasmosis in a patient with advanced acquired immunodeficiency syndrome

Extracerebral toxoplasmosis, with pulmonary involvement and shock, is a rare form of toxoplasmosis in patients with advanced AIDS. It can mimic pneumocystosis, histoplasmosis, and disseminated tuberculosis, and should be considered in the differential diagnosis of causes of respiratory failure and fulminant disease in this group of individuals, especially in areas where the Toxoplasma gondii infection is highly prevalent and in those without proper use of antimicrobial prophylaxis. We report the case of a 46-year-old male patient who presented to the emergency department with uremia, requiring urgent dialysis. During the laboratorial investigation, the patient had confirmed HIV infection, with a low CD4+ peripheral T-cell count (74 cells/µL). During hospitalization, the patient presented drug-induced hepatitis due to trimethoprim/sulfamethoxazole in a prophylactic dose, requiring interruption of this medication. On the 55th day of hospitalization, the patient developed refractory shock and died. At the autopsy, disseminated toxoplasmosis with encephalitis and severe necrotizing pneumonia were diagnosed, with numerous tachyzoites in the areas of pulmonary necrosis.

Respiratory distress of unknown etiology in a transplant recipient: think toxoplasmosis!

Disseminated toxoplasmosis is a life-threatening disease in immunocompromised individuals. Infection is contracted from handling contaminated soil, cat litter, or through the consumption of contaminated water or food. It is the third most common lethal foodborne infection in the United States. In transplant patients, most cases occur as a result of reactivation of a latent infection resulting from immunosuppression. We present a case of disseminated toxoplasmosis diagnosed at the time of autopsy. This case emphasizes the importance of maintaining a high index of clinical suspicion and active disease surveillance in this era of sophisticated diagnostic testing.

Detection of antibodies to Toxoplasma gondii in wild animals in Brazil

Toxoplasmosis is a worldwide zoonosis caused by an obligate intracellular protozoan parasite, Toxoplasma gondii, that affects all warm-blooded animals, including wild animals. The increased number of cases of parasitic infections is mainly due to the destruction of environmental conservation areas, which is driving wild animals out of their habitats and towards urban areas. In this study, the occurrence of T. gondii infection was investigated by the modified agglutination test (MAT) in 26 different species of run over and injured wild animals that were treated at a Brazilian university veterinary hospital, from June 2007 to August 2008. Of the studied animals, six (23.1%; CI95% 11.1-42.2%) had T. gondii antibodies, with titers equal to 10 (4; 66.7%) and 40 (2; 33.3%). The species Pseudalopex vetulus, Cerdocyon thous, Hydrochoerus hydrochaeris and Tapyrus terrestris had titers of 10, while Alouatta caraya and Puma concolor had titers of 40. There was no significant association regarding age, gender or purpose of care (p > 0.05). Carnivorous, herbivorous and omnivorous wild animals are potential sentinels of human toxoplasmosis, especially when wild felids are present, maintaining the environmental contamination.

Toxoplasmose e Toxoplasma gondii / Toxoplasmosis and Toxoplasma gondii

A infecção por Toxoplasma gondii é hoje muito disseminada ao redor do mundo, especialmente no Brasil. A coletânea parte da história da descoberta desse parasita e da doença por ele causada, a toxoplasmose, e visita os diferentes aspectos relacionados ao tema. São apresentados o ciclo evolutivo, a epidemiologia, o diagnóstico, o quadro clínico e o tratamento, em uma ampla revisão sobre o assunto, provavelmente a mais completa já realizada. Somente nos anos 1970 desvendou-se o ciclo de vida desse protozoário, do qual o gato é hospedeiro definitivo. Outros animais de sangue quente, entre eles o ser humano, são hospedeiros intermediários. Muitos indivíduos infectados pelo T. gondii não apresentam sintomas, mas, quando a doença se manifesta, pode ter diferentes configurações, afetando gânglios, olhos, coração, pulmões, fígado, cérebro e meninges, ou articulações. Além de uma completa revisão, a obra também traz para o leitor o que há de mais atual no conhecimento científico acerca da toxoplasmose e do T. gondii. O livro cobre praticamente todos os campos do conhecimento sobre o agente etiológico e a doença, apresentando novos aspectos, particularmente em relação à bioquímica, à interação entre o parasita e a célula hospedeira e à resposta imunológica à infecção.

Parasitosis intestinales y tisulares y su relación con la eosinofilia en una comunidad indígena Yukpa de la Sierra de Perijá, estado Zulia / Intestinal and tissue parasites and their relation with eosinophilia in a Yukpa Amerindian community from the Mountains of Perijá, state of Zulia

Para determinar la prevalencia de parasitosis intestinales y tisulares y su relación con la eosinofilia en una comunidad indígena Yukpa, se analizaron 91 muestras fecales y sanguíneas. A las muestras fecales se les practicó examen coproscópico y concentrado. Se realizó hematología completa para determinar cuenta blanca y porcentaje de eosinófilos, y en suero se efectuó un test de ELISA para la detección de anticuerpos anti- Toxocara canis y anti- Toxoplasma gondii. Se observó una elevada prevalencia de parasitosis intestinales (90,10%). Se apreció predominio de protozoarios sobre helmintos, siendo para los primeros el más prevalente Blastocystis sp. (51,64%) y para los segundos Ascaris lumbricoides (38,46%). La seroprevalencia de anticuerpos anti-Toxocara canis fue de 24,17% y anti-Toxoplasma gondii de 43.95%. No se observó diferencias estadísticamente significativas entre los grupos de edad y sexo en las diferentes parasitosis intestinales y tisulares. No se encontró asociación entre la seroprevalencia para Toxocara canis y la eosinofilia. Se apreció una asociación estadística significativa entre la presencia de eosinofilia y las helmintiasis. Estos resultados sugieren que existe una alta prevalencia de infecciones parasitarias en estas comunidades debido probablemente a sus costumbres y las condiciones sanitarias en las que habitan.

To determine the prevalence of intestinal and tissue parasites and their relationship with eosinophilia in Yukpa Amerindians, 91 fecal and blood samples were analyzed. The fecal samples underwent microscopic and concentrated examinations. Complete hematology was performed to determine white count and percentage of eosinophils; and ELISA tests were performed on the serum to detect anti-Toxocara canis and anti-Toxoplasma gondii antibodies. A high prevalence of intestinal parasites (90.10%) was observed. The predominance of protozoa over helminths was noted; for the first, the most prevalent were Blastocystis hominis (51.64%), and for the second, Ascaris lumbricoides (38.46%). Seroprevalence of anti-Toxocara canis antibodies was 24.17% and for anti-Toxoplasma gondi, 43.95%. No statistically significant differences were observed between age and sex groups for the different intestinal and tissue parasites. No association between seroprevalence for Toxocara canis and eosinophilia was found. A statistically significant association between the presence of eosinophilia and helminthiasis was observed. These results suggest that there is a high prevalence of parasitic infections in these communities due probably to their customs and the sanitary conditions in which they live.

Depletion of CD25+ cells during acute toxoplasmosis does not significantly increase mortality in Swiss OF1 mice

The interleukin (IL)-2R alpha chain (CD25) is expressed on regulatory T cells (Treg), which constitute more than 85 percent of the CD25+ T cell population in a naïve mouse. CD25 is also expressed on effector T cells in mice suffering from an acute infection by the obligate intracellular protozoan parasite, Toxoplasma gondii. Lethal toxoplasmosis is accompanied by a significant loss of Treg in mice naturally susceptible to toxoplasmosis. The present study was done to explore the role of Treg cells using an anti-CD25 antibody-mediated depletion in mice naturally resistant to toxoplasmosis. Although a significant decrease in the percentage of Treg cells was observed following anti-CD25 monoclonal antibody injections, the depletion of CD25+ cells during acute toxoplasmosis did not significantly increase the mortality of Swiss OF1 mice and no significant difference was observed in the brain parasitic load between the mice in the depleted-infected and isotype-infected groups. We found no significant difference between the titres of total IgG in the sera of the mice from the two groups in the chronic phase. However, CD25+ cells depletion was followed by significantly higher levels of IL-12 in the serum of depleted mice than in that of mice injected with the isotype control antibody.

Disseminated toxoplasmosis in an immunocompetent patient from Peruvian Amazon / Toxoplasmosis diseminada en un paciente inmunocompetente procedente de la Amazonía peruana

We report a case of severe toxoplasmosis in an immunocompetent patient, characterized by pneumonia, retinochoroiditis, hepatitis and myositis. Diagnosis was confirmed by serology, T. gondii in thick blood smear and presence of bradyzoites in muscle biopsy. Treatment with pyrimethamine plus sulfadoxine was successful but visual acuity and hip extension were partially recovered. This is the first case report of severe toxoplasmosis in an immunocompetent patient from Peru.

Reportamos un caso de toxoplasmosis severa en un paciente inmunocompetente caracterizado por neumonía, retinocoroiditis, hepatitis y miositis. El diagnóstico fue confirmado por serología, el hallazgo de T. gondii en gota gruesa y la presencia de bradizoitos en biopsia muscular. El tratamiento con pirimetamina mas sulfadoxina fue exitoso pero solo hubo una parcial recuperación de la agudeza visual y de la capacidad de extensión de la cadera. Este es el primer reporte de un caso de toxoplasmosis severa en el Perú.

Diagnosis of disseminated toxoplasmosis by polymerase chain reaction in bronchoalveolar lavage fluid of a patient with aids / Diagnóstico de toxoplasmose disseminada através de técnica de reação em cadeia da polimerase realizada no lavado bronco-alveolar de paciente com sida

Pulmonary toxoplasmosis is a challenging diagnosis in immunosuppressed patients with nonspecific clinical picture and radiologic findings. We present a case of pneumonia due to Toxoplasma gondii diagnosed by polymerase chain reaction (PCR) in the bronchoalveolar lavage (BAL) fluid of a patient with acquired immunodeficiency syndrome (AIDS). Coinfection with Pneumocystis jirovecii was found in the same specimen. Direct examination and culture for bacteria, mycobacteria and other fungus were negative. Despite the intensive management, respiratory compromise evolved rapidly, with the need for ventilatory support. Acute respiratory distress syndrome developed, and the patient died of multiple organ failure. This case illustrates that a high index of suspicion is necessary for diagnosis of pulmonary toxoplasmosis, a potentially fatal condition. Due to high diagnostic performance, PCR in BAL fluid should be included in the evaluation of immunosuppressed patients with nonspecific pulmonary diseases.

O diagnóstico de toxoplasmose pulmonar em pacientes imunossuprimidos é difícil, devido ao quadro clínico e aos achados radiológicos inespecíficos. Neste artigo, relatamos o caso de uma paciente com síndrome da imunodeficiência adquirida (SIDA), que apresentou pneumonia por Toxoplasma gondii diagnosticada através de reação em cadeia da polimerase (PCR) no lavado bronco-alveolar (LBA). A paciente apresentava co-infecção com Pneumocystis jirovecii. Os demais exames microbiológicos, como bacterioscópico, cultural para bactérias, micobactérias e fungos, foram negativos. Apesar do manejo intensivo, a paciente evoluiu com síndrome do desconforto respiratório agudo e óbito por falência múltipla dos órgãos. Este caso demonstra que um alto índice de suspeita clínica é necessário para o diagnóstico de pneumonia por Toxoplasma gondii. Devido ao seu desempenho diagnóstico, o PCR para Toxoplasma gondii no LBA deve ser incluído na avaliação de pacientes imunossuprimidos com quadros pulmonares inespecíficos.

Disseminated toxoplasmosis presenting as sepsis in two AIDS patients

This report describes two patients who presented acute disseminated and severe toxoplasmosis as the first opportunistic disease related to acquired immunodeficiency syndrome. At admission, clinical and laboratory findings were similar to sepsis or septic shock and a fast evolutive course to death occurred in both cases. At necropsy, an inflammatory reaction and presence of a great number of Toxoplasma gondii cysts and tachyzoites were observed in most organs examined.

O presente relato descreve dois pacientes que apresentaram toxoplasmose aguda, disseminada e grave como primeira manifestação oportunista da síndrome da imunodeficiência adquirida. Os achados clínicos e laboratoriais foram similares aos de sepse ou choque séptico e, em ambos os casos houve evolução rápida para óbito. A necropsia, foi observada reação inflamatória e presença de taquizoítos e cistos de Toxoplasma gondii na maioria dos órgãos examinados.

Sudden death due to cardiac toxoplasmosis.

The recognition of cardiac toxoplasmosis has increased in patients with acquired immunodeficiency syndrome. The functional consequences of toxoplasmosis of heart vary considerably depending on the intensity of inflammatory reaction, the extent of involvement of myocardial muscle fibers by necrosis and intramyocytic presence of tachyzoites of Toxoplasma gondii. This report describes a case of toxoplasma myocarditis that lead to fatal cardiac arrest. To the best of our knowledge, this is the first reported case of cardiac toxoplasmosis in the Indian literature, which has manifested as sudden death.

Estudo histopatológico e imuno-histoquímico de camundongos infectados por Toxoplasma gondii e alimentados com micotoxinas / Histopathologic and immunohistochemical study of mice infected for Toxoplasma gondii and fed with mycotoxins

A toxoplasmose,importante infecção em gestantes,vem se mostrando também como uma das enfermidades oportunistas mais freqüentes em indivíduos imunocomprometidos.Dentre as...concentrações já são capazes de causar efeitos imunomodulatórios.Sendo assim,com o presente trabalho buscou-se avaliar por meio da análise histopatológica e imuno-histoquímica o curso da infecção pelo Toxoplasma gondii em camundongos alimentados com micotoxinas.Para tanto,camundongos da linhagem C57BL/6,infectados pela cepa ME49 do T.gondii,foram alimentados com ração experimental contendo baixas dosagens das micotoxinas: aflatoxina B1,fumonisina B1,citrinina e ocratoxina A, isoladas ou associadas.Os animais foram divididos em grupos de acordo com a infecção e alimentação da seguinte forma:C-C(controle-controle),C-F(controle-fumonisina B1), C-FA(controle-fumonisina B1 + aflatoxina B1),C-CO (controle-citrinina + ocratoxina A),C-MIX(controle-mix das 4 micotoxinas),I-C(infectado-controle),I-F(infectado-fumnonisina B1),I-FA(infectado-fumonisina B1 + aflatoxina B1),I-CO(infectado-citrinina + ocratoxina A),I-MIX (infectado-mix das 4 micotoxinas).Para a visualização de lesões,assim como de estruturas parasitárias e sua dispersão nos tecidos do hospedeiro,foram analisadas amostras de cérebro,fígado,rim,pulmão,musculaturas esquelética e cardíaca.Os animais alimentados com micotoxinas e infectados com T.gondii apresentaram as lesões mais acentuadas foram representadas por quadros de encefalite,hepatite,focos de necrose encefálica e hepática,mostrando que a associação entre parasitismo e micotoxicose causou um agravamento nas lesões uma vez que animais somente infectados ou somente intoxicados apresentaram alterações histopatológicas mais brandas.O grupo I-CO apresentou ainda um quadro de glomérulo-nefrite que poderia estar relacionado à associação da infecção com a micotoxicose,uma vez que não foi observada alteração em grupos com tais eventos ocorrendo separadamente.A fumonisina B1(isolada ou associada à outra micotoxina)foi responsável por alterações celulares como gigantismo nuclear e hipertrofia celular e células atípicas em tecido hepático.Essa micotoxina foi relacionada também a quadros de desmielinização em tecido cerebral.A presença de cistos ou formas livres do T.gondii foi constatada tanto em animais controle quanto nos alimentados com micotoxinas,mostrando que a cepa do parasita nesta linhagem de camundongos,apresenta formas características de fase aguda e crônica da infecção.

Toxoplasma gondii myelitis in a patient with adult T-cell leukemia-lymphoma

Adult T cell leukemia-lymphoma (ATL) caused by HTLV-I may be associated with severe immunosupression and several opportunistic infections. Toxoplasmic encephalitis is a common central nervous system opportunistic infection in severely immunosupressed patients, however spinal cord involvement by this parasite is rare. In this paper, we report a case of toxoplasmic myelitis in a patient with ATL

Toxoplasmose: etiologia, avaliação laboratorial e profilaxia / Toxoplasmosis: etiology, laboratorial assessment and profilaxy

A Toxoplasmose é doença infecto-contagiosa, de larga prevalência em nosso meio, já foi investigada, por algum tempo, como provável causa de aborto. Entretanto, a sua maior importância está voltada para lesóes oculares e as lesões causadas no feto. Dessa forma, os exames laboratoriais passaram a ter muita importância não apenas no diagnóstico da doença em sua fase aguda, mas também no acompanhamento de gestantes soro-negativas como medida profilática de má formação congênita. Neste trabalho, busca-se, uniformizar os conceitos, padronizar a interpretação dos resultados laboratoriais e as medidas profiláticas relativas à doença.

Meningoencefalites toxoplásmica e chagásica em pacientes com infecção pelo vírus da imunodeficiência humana: diagnóstico diferencial anatomopatológico e tomográfico / Toxoplasmic and chagasic meningoencephalitis in patients with human immunodeficiency virus infection: anatomopathologic and tomographic differential diagnosis

Em 22 pacientes com sorologia positiva para o vírus da imunodeficiência humana, com ou sem síndrome da imunodeficiência adquirida, dos quais 7 com meningoencefalite toxoplásmica e 15 com meningoencefalite chagásica associadas, procuraram-se dados diferenciais, entre as duas encefalopatias, tanto à anatomia patológica quanto à tomografia computadorizada do crânio. Os resultados observados e os dados da literatura nos permitiram concluir que enquanto na meningoencefalite necrosante focal por Toxoplasma gondii o acometimento dos núcleos da base é freqüente, na meningoencefalite necrosante focal causada pelo Trypanosoma cruzi, lesões dessas estruturas parecem não ocorrer ou ser excepcionais. De outro lado, o acometimento da substância branca parece nitidamente maior na meningoencefalite chagásica que na meningoencefalite toxoplásmica, ao passo que o parasitismo e a hemorragia do tecido nervoso, bem como as lesões das bainhas de mielina são mais freqüentes e intensos na meningoencefalite causada pelo Trypanosoma cruzi que naquela por Toxoplasma.

Twenty-two HIV+ patients with encephalitis were studied. Of these, 7 had meningoencephalitis due to Toxoplasma gondii (MT) and 15 due to Trypanosoma cruzi (MC). Pathologic and computerized axial tomography (CAT) changes were compared. We found that focal necrotizing encephalitis due to Toxoplasma involved the cerebral cortex and the basal ganglia, whereas lesions due to Trypanosoma cruzi were centered in the white matter, sometimes extending into the cortex. Hemorrhages, myelin lesions and organisms were more pronounced in chagasic than in toxoplasmic encephalitis. These findings are consistent with the literature reviewed.

Experimental toxoplasmosis, and immunosupression (parasite evaluation and histological alterations)

Com a finalidade de estudar a acao das drogas imunossupressoras nas parasitoses, estudamos a Cyclosporina A e Cortisona na toxoplasmose experimental, utilizando uma cepa altamente virulenta do Toxoplasma gondii (cepa RH). Os animais foram divididos em dois lotes: controle e imunodeprimidos, sendo avaliados pela pesquisa da parasitemia e parasitismo do exsudato peritoneal, e parasitismo do coracao, figado, baco, pancreas, intestino, rim, supra renal, cerebro, cerebelo, medula espinhal e globo ocular sendo sacrificados diariamente dois animais de cada grupo. O parasitismo do exsudato peritoneal foi dez vezes maior que a parasitemia do segundo dia, foram encontradas manchas avermelhadas e do quarto dia, necroses focais com areas de amolecimento e liquefacao da massa encefalica salpicadas no tecido nervoso...

Inmunodiagnostico de la toxoplasmosis: hemaglutinación indirecta e inmunoanalisis enzimatico IgM e IgG / Immunodiagnosis of the toxoplasmosis: indirect hemagglutination IgM and IgG enzime linked immunosorbent assay

En el presente trabajo se compararon los métodos de Hemaglutinación Indirecta (HAI) e Inmunoanálisis Enzimático (ELISA, IgM e IgG) para investigar anticuerpos antitoxoplasma en 54 muestras sanguíneas. Los resultados obtenidos muestran una concordancia del 62.96 por ciento entre HAI y ELISA. IgM y del 83.33 por ciento entre HAI y ELISA. IgG. El análisis estadístico mediante el chi cuadrado, reveló que hubo significancia cuando se compararon todos los títulos de HAI a partir de 1:2 con todos los índices de ELISA. IgM, esta significancia no puede establecer la superioridad de un método sobre el otro, debido: a. La utilización del "kit" comercial ELISA. IgM que solo detecta este tipo de anticuerpo; b. La detección por HAI de IgM e IgG; c. La presencia de anticuerpos inespecíficos de HAI y ELISA. IgG reveló que no hubo diferencias, lo cual nos indica que la discordancia entre ambos métodos no es estadísticamente significante