Ovine toxoplasmosis

Parasitology ◽  
2009 ◽  
Vol 136 (14) ◽  
pp. 1887-1894 ◽  
Author(s):  
ELISABETH A. INNES ◽  
PAUL M. BARTLEY ◽  
DAVID BUXTON ◽  
FRANK KATZER
Keyword(s):  
Immune Responses ◽  
Congenital Toxoplasmosis ◽  
Clinical Importance ◽  
Congenital Infection ◽  
Subsequent Pregnancy ◽  
Current Debate ◽  
Transplacental Transmission ◽  
Source Of Infection ◽  
Peripheral Lymph ◽  
Chronic Cannulation

SUMMARYCongenital infection with Toxoplasma gondii is an important cause of abortion in sheep worldwide. The cat is the definitive host of the parasite, and infected cats may shed millions of oocysts in their faeces resulting in extensive environmental contamination and an important source of infection for grazing herbivorous animals. Studies looking at development of specific antibodies in sheep, as an indicator of exposure to T. gondii, have shown that there is an increase in seroprevalence associated with age indicating that most infections in sheep occur following birth. The stage of gestation when transplacental transmission of T. gondii to the developing foetus occurs is critical in determining the clinical outcome. The importance of endogenous transplacental transmission in persistently infected ewes and its clinical importance is a subject of current debate. Ewes infected prior to mating develop immune responses that help protect against disease in a subsequent pregnancy and also against experimental challenge administered during pregnancy. Both innate and adaptive immune responses are activated following T. gondii infection and experiments involving the chronic cannulation of peripheral lymph nodes in sheep have allowed the dynamics of the immune responses to be analysed in real time. A live vaccine, Toxovax® is the only commercially available vaccine worldwide to protect against congenital toxoplasmosis.

scholarly journals Vaccines in Congenital Toxoplasmosis: Advances and Perspectives

2021 ◽  
Vol 11 ◽  
Author(s):  
Mariana Barros ◽  
Daniela Teixeira ◽  
Manuel Vilanova ◽  
Alexandra Correia ◽  
Natercia Teixeira ◽  
...  
Keyword(s):  
Immune Response ◽  
Animal Models ◽  
Immune Responses ◽  
Congenital Toxoplasmosis ◽  
Congenital Infection ◽  
Transmitted Infection ◽  
Subunit Vaccines ◽  
Parasitic Burden ◽  
Induced Immunity ◽  
Maternal Fetal Interface

Congenital toxoplasmosis has a high impact on human disease worldwide, inducing serious consequences from fetus to adulthood. Despite this, there are currently no human vaccines available to prevent this infection. Most vaccination studies against Toxoplasma gondii infection used animal models in which the infection was established by exogenous inoculation. Here, we review recent research on potential T. gondii vaccines using animal models in which infection was congenitally established. Endeavors in this field have so far revealed that live or subunit vaccines previously found to confer protection against extrinsically established infections can also protect, at least partially, from vertically transmitted infection. Nevertheless, there is no consensus on the more adequate immune response to protect the host and the fetus in congenital infection. Most of the vaccination studies rely on the assessment of maternal systemic immune responses, quantification of parasitic loads in the fetuses, and survival indexes and/or brain parasitic burden in the neonates. More research must be carried out not only to explore new vaccines but also to further study the nature of the elicited immune protection at the maternal-fetal interface. Particularly, the cellular and molecular effector mechanisms at the maternal-fetal interface induced by immunization remain poorly characterized. Deeper knowledge on the immune response at this specific location will certainly help to refine the vaccine-induced immunity and, consequently, to provide the most effective and safest protection against T. gondii vertical infection.

scholarly journals Growth Hormone Deficiency in Congenital Toxoplasmosis

2018 ◽  
Vol 08 (01) ◽  
pp. e43-e45
Author(s):  
Juma Natsheh ◽  
Bassam Abu-Libdeh ◽  
Abdulsalam Abu-Libdeh
Keyword(s):  
Growth Hormone ◽  
Growth Hormone Deficiency ◽  
Congenital Toxoplasmosis ◽  
Congenital Infection ◽  
Failure To Thrive ◽  
Female Infant ◽  
Pituitary Function ◽  
Hormone Deficiency ◽  
Neurological Abnormalities

AbstractCongenital toxoplasmosis represents the second most commonly recognized congenital infection. Ocular and neurological abnormalities are considered the most frequent sequelae. Endocrinological manifestations are rare and have received little attention. We report a 3.5-month-old female infant who presented with failure to thrive and recurrent hypoglycemic attacks, diagnosed as growth hormone deficiency due to sequelae of congenital toxoplasmosis. Although endocrinological sequelae of congenital toxoplasmosis are uncommon, they represent potentially treatable conditions. Here, we stress on the importance of monitoring pituitary function and growth in children in particular, with congenital toxoplasmosis, keeping in mind other possible, potentially treatable, endocrinological manifestations.

scholarly journals Maternal and Congenital Toxoplasmosis: Diagnosis and Treatment Recommendations of a French Multidisciplinary Working Group

Pathogens ◽  
2019 ◽  
Vol 8 (1) ◽  
pp. 24 ◽  
Author(s):  
François Peyron ◽  
Coralie L’ollivier ◽  
Laurent Mandelbrot ◽  
Martine Wallon ◽  
Renaud Piarroux ◽  
...  
Keyword(s):  
Working Group ◽  
Congenital Toxoplasmosis ◽  
Congenital Infection ◽  
Before And After ◽  
Multidisciplinary Working ◽  
Neurological Alterations ◽  
Multidisciplinary Group ◽  
Toxoplasmosis During Pregnancy

Women infected with toxoplasmosis during pregnancy do not present symptoms in most cases, but the consequences of the congenital infection may be severe for the unborn child. Fetal damage can range from asymptomatic to severe neurological alterations to retinal lesions prone to potential flare up and relapses lifelong. Despite the possible severity of outcome, congenital toxoplasmosis (CT) is a neglected disease. There is no consensus regarding screening during pregnancy, prenatal/postnatal treatment or short or medium term follow-up. Since 1992, France has offered systematic serological testing to non-immune pregnant women, monthly until delivery. Any maternal infection is thus detected; moreover, diagnosis of congenital infection can be made at birth and follow-up can be provided. “Guidelines” drawn up by a multidisciplinary group are presented here, concerning treatment, before and after birth. The recommendations are based on the regular analysis of the literature and the results of the working group. The evaluation of the recommendations takes into account the robustness of the recommendation and the quality of the evidence.

scholarly journals RHΔgra17Δnpt1 Strain of Toxoplasma gondii Elicits Protective Immunity Against Acute, Chronic and Congenital Toxoplasmosis in Mice

2020 ◽  
Vol 8 (3) ◽  
pp. 352 ◽  
Author(s):  
Qin-Li Liang ◽  
Li-Xiu Sun ◽  
Hany M. Elsheikha ◽  
Xue-Zhen Cao ◽  
Lan-Bi Nie ◽  
...  
Keyword(s):  
Toxoplasma Gondii ◽  
Cellular Response ◽  
Protective Efficacy ◽  
Interleukin 2 ◽  
Congenital Toxoplasmosis ◽  
Congenital Infection ◽  
Dense Granule ◽  
Lethal Challenge ◽  
Double Deletion ◽  
Brain Cysts

In the present study, a dense granule protein 17 (gra17) and novel putative transporter (npt1) double deletion mutant of Toxoplasma gondii RH strain was engineered. The protective efficacy of vaccination using RHΔgra17Δnpt1 tachyzoites against acute, chronic, and congenital toxoplasmosis was studied in a mouse model. Immunization using RHΔgra17Δnpt1 induced a strong humoral and cellular response, as indicated by the increased levels of anti-T. gondii specific IgG, interleukin 2 (IL-2), IL-10, IL-12, and interferon-gamma (IFN-γ). Vaccinated mice were protected against a lethal challenge dose (103 tachyzoites) of wild-type homologous (RH) strain and heterologous (PYS and TgC7) strains, as well as against 100 tissue cysts or oocysts of Pru strain. Vaccination also conferred protection against chronic infection with 10 tissue cysts or oocysts of Pru strain, where the numbers of brain cysts in the vaccinated mice were significantly reduced compared to those detected in the control (unvaccinated + infected) mice. In addition, vaccination protected against congenital infection with 10 T. gondii Pru oocysts (administered orally on day 5 of gestation) as shown by the increased litter size, survival rate and the bodyweight of pups born to vaccinated dams compared to those born to unvaccinated + infected dams. The brain cyst burden of vaccinated dams was significantly lower than that of unvaccinated dams infected with oocysts. Our data show that T. gondii RHΔgra17Δnpt1 mutant strain can protect mice against acute, chronic, and congenital toxoplasmosis by balancing inflammatory response with immunogenicity.

scholarly journals Incidence of congenital toxoplasmosis in southern Brazil: a prospective study

2003 ◽  
Vol 45 (3) ◽  
pp. 147-151 ◽  
Author(s):  
Liége Mozzatto ◽  
Renato Soibelmann Procianoy
Keyword(s):  
Toxoplasma Gondii ◽  
Gestational Age ◽  
Newborn Infants ◽  
Congenital Toxoplasmosis ◽  
Congenital Infection ◽  
First Trimester ◽  
Laboratory Diagnosis ◽  
Anthropometric Measures ◽  
Maternal Characteristics ◽  
The Town

The study aimed to determine the incidence of congenital infection by Toxoplasma gondii and to describe neonatal and maternal characteristics regarding newborn infants treated at a teaching hospital in the town of Passo Fundo, State of Rio Grande do Sul, Brazil. Cord blood samples collected from 1,250 live newborns were analyzed. The laboratory diagnosis was established by the detection of Toxoplasma gondii IgM using an enzyme linked fluorescent assay. Gestational age, intrauterine growth, anthropometric measures, and prenatal characteristics were assessed. The incidence of congenital toxoplasmosis at birth was 8/10,000 (95%CI 0.2-44.5). Mean birthweight was 3,080 ± 215.56 grams and mean gestational age was 38.43 ± 1.88 weeks. With regard to prenatal care, 58% of the pregnant patients visited their doctors five times or more and 38.9% were serologically tested for toxoplasmosis in the first trimester of pregnancy. The incidence of congenital toxoplasmosis was similar to that found in most studies conducted in our country and abroad. Our study sample is representative of the town of Passo Fundo and therefore it is possible to consider the frequency observed as the prevalence of the disease in this town during the study period.

scholarly journals HIV-1 Nef and Vpu Interfere with L-Selectin (CD62L) Cell Surface Expression To Inhibit Adhesion and Signaling in Infected CD4+T Lymphocytes

2015 ◽  
Vol 89 (10) ◽  
pp. 5687-5700 ◽  
Author(s):  
Lia Vassena ◽  
Erica Giuliani ◽  
Herwig Koppensteiner ◽  
Sebastian Bolduan ◽  
Michael Schindler ◽  
...  
Keyword(s):  
T Cells ◽  
Plasma Membrane ◽  
T Lymphocytes ◽  
Cell Surface ◽  
Immune Responses ◽  
Lymph Nodes ◽  
Viral Proteins ◽  
Peripheral Lymph ◽  
Leukocyte Homing ◽  
Hiv 1

ABSTRACTLeukocyte recirculation between blood and lymphoid tissues is required for the generation and maintenance of immune responses against pathogens and is crucially controlled by the L-selectin (CD62L) leukocyte homing receptor. CD62L has adhesion and signaling functions and initiates the capture and rolling on the vascular endothelium of cells entering peripheral lymph nodes. This study reveals that CD62L is strongly downregulated on primary CD4+T lymphocytes upon infection with human immunodeficiency virus type 1 (HIV-1). Reduced cell surface CD62L expression was attributable to the Nef and Vpu viral proteins and not due to increased shedding via matrix metalloproteases. Both Nef and Vpu associated with and sequestered CD62L in perinuclear compartments, thereby impeding CD62L transport to the plasma membrane. In addition, Nef decreased total CD62L protein levels. Importantly, infection with wild-type, but not Nef- and Vpu-deficient, HIV-1 inhibited the capacity of primary CD4+T lymphocytes to adhere to immobilized fibronectin in response to CD62L ligation. Moreover, HIV-1 infection impaired the signaling pathways and costimulatory signals triggered in primary CD4+T cells by CD62L ligation. We propose that HIV-1 dysregulates CD62L expression to interfere with the trafficking and activation of infected T cells. Altogether, this novel HIV-1 function could contribute to virus dissemination and evasion of host immune responses.IMPORTANCEL-selectin (CD62L) is an adhesion molecule that mediates the first steps of leukocyte homing to peripheral lymph nodes, thus crucially controlling the initiation and maintenance of immune responses to pathogens. Here, we report that CD62L is downmodulated on the surfaces of HIV-1-infected T cells through the activities of two viral proteins, Nef and Vpu, that prevent newly synthesized CD62L molecules from reaching the plasma membrane. We provide evidence that CD62L downregulation on HIV-1-infected primary T cells results in impaired adhesion and signaling functions upon CD62L triggering. Removal of cell surface CD62L may predictably keep HIV-1-infected cells away from lymph nodes, the privileged sites of both viral replication and immune response activation, with important consequences, such as systemic viral spread and evasion of host immune surveillance. Altogether, we propose that Nef- and Vpu-mediated subversion of CD62L function could represent a novel determinant of HIV-1 pathogenesis.

scholarly journals Evaluation of the Liaison Automated Testing System for Diagnosis of Congenital Toxoplasmosis

2012 ◽  
Vol 19 (11) ◽  
pp. 1859-1863 ◽  
Author(s):  
Andrea-Romana Prusa ◽  
Michael Hayde ◽  
Arnold Pollak ◽  
Kurt R. Herkner ◽  
David C. Kasper
Keyword(s):  
Predictive Value ◽  
Congenital Toxoplasmosis ◽  
Congenital Infection ◽  
Confirmatory Test ◽  
Diagnostic Tools ◽  
First Year ◽  
Study Cohort ◽  
Serum Samples ◽  
Content Type ◽  
First Year Of Life

ABSTRACTCongenital toxoplasmosis is a worldwide health problem, and different screening strategies exist. Testing of toxoplasma-specific antibodies in infants identifies congenital toxoplasmosis during the first year of life. However, experience with commercial available immunoassays is limited. The aim of this study was to evaluate both the performance and analytical characteristics of the Liaison diagnostic system in infants. In a retrospective study, serumToxoplasma gondiiantibodies were measured in samples from 333 infants, including 212 noninfected infants and 121 infants with congenital toxoplasmosis. A total of 1,157 umbilical cord blood and peripheral serum samples were analyzed. Liaison toxoplasma-specific IgG and IgM antibodies and the IgG avidity index were compared to the infection status of the infant, determined by the Sabin-Feldman dye test and immunosorbent agglutination assay—IgM. All noninfected infants were seronegative by Liaison IgG within the first year of life. The Liaison system showed a sensitivity of 81.8%, a specificity of 100.0%, a positive predictive value of 100.0%, a negative predictive value of 90.6%, and overall agreement of 84.4% by comparison with the dye test. Overall agreement of both IgM test systems was 96.0%. In this study cohort, avidity did not show a potential diagnostic benefit for the detection of congenital infection. In conclusion, the Liaison system is a valuable tool to monitor the serologic course of infants at risk. A final serologic confirmatory test is recommended to improve the rate of detection of congenital toxoplasmosis at 1 year of life. Protocols of routine follow-up testing in infants and accurate diagnostic tools after acute gestational infections are needed to improve medical care.

scholarly journals The development of the Sabin–Pinkerton triad despite prenatal screening for congenital toxoplasmosis

2021 ◽  
Vol 17 (3) ◽  
pp. 270-274
Author(s):  
Urszula Dryja ◽  
◽  
Anna Niwald ◽  
Ewa Majda-Stanisławska ◽  
◽  
...  
Keyword(s):  
Toxoplasma Gondii ◽  
Prenatal Screening ◽  
Congenital Toxoplasmosis ◽  
Congenital Infection ◽  
First Trimester ◽  
Imaging Findings ◽  
Pregnant Mother ◽  
First Trimester Of Pregnancy ◽  
Toxoplasma Gondii Infection ◽  
Antiparasitic Treatment

The paper presents a case of a boy who developed the symptoms of congenital toxoplasmosis: hydrocephalus, retinitis, choroiditis and intracranial calcifications (the Sabin–Pinkerton triad). Despite prenatal screening in the first trimester of pregnancy (in accordance with the guidelines of the Ministry of Health), which indicated the diagnosis of asymptomatic primary Toxoplasma gondii infection in the pregnant mother, no antiparasitic therapy was used. The presented serological and imaging findings, as well as specialist consultations confirm the intensified effects of congenital infection in the child. Although the child was put on anti-toxoplasma therapy immediately after birth, he developed severe psychophysical development disorders. The paper discusses recommendations for maternal diagnosis and antiparasitic treatment that could have prevented the full-blown congenital toxoplasmosis in the described patient.

scholarly journals Is It Possible to Intervene in the Capacity of Trypanosoma cruzi to Elicit and Evade the Complement System?

2021 ◽  
Vol 12 ◽  
Author(s):  
Galia Ramírez-Toloza ◽  
Lorena Aguilar-Guzmán ◽  
Carolina Valck ◽  
Smrithi S. Menon ◽  
Viviana P. Ferreira ◽  
...  
Keyword(s):  
Latin America ◽  
Trypanosoma Cruzi ◽  
Immune Responses ◽  
Chagas Disease ◽  
Complement System ◽  
Significant Inhibition ◽  
Transplacental Transmission ◽  
Global Expansion ◽  
The Complement System ◽  
Evasive Strategy

Chagas’ disease is a zoonotic parasitic ailment now affecting more than 6 million people, mainly in Latin America. Its agent, the protozoan Trypanosoma cruzi, is primarily transmitted by endemic hematophagous triatomine insects. Transplacental transmission is also important and a main source for the emerging global expansion of this disease. In the host, the parasite undergoes intra (amastigotes) and extracellular infective (trypomastigotes) stages, both eliciting complex immune responses that, in about 70% of the cases, culminate in permanent immunity, concomitant with the asymptomatic presence of the parasite. The remaining 30% of those infected individuals will develop a syndrome, with variable pathological effects on the circulatory, nervous, and digestive systems. Herein, we review an important number of T. cruzi molecules, mainly located on its surface, that have been characterized as immunogenic and protective in various experimental setups. We also discuss a variety of parasite strategies to evade the complement system - mediated immune responses. Within this context, we also discuss the capacity of the T. cruzi infective trypomastigote to translocate the ER-resident chaperone calreticulin to its surface as a key evasive strategy. Herein, it is described that T. cruzi calreticulin inhibits the initial stages of activation of the host complement system, with obvious benefits for the parasite. Finally, we speculate on the possibility to experimentally intervene in the interaction of calreticulin and other T. cruzi molecules that interact with the complement system; thus resulting in significant inhibition of T. cruzi infectivity.

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