Protein profile of purified plasma- and aqueous humor-derived extracellular vesicles from patients with ocular toxoplasmosis

ABSTRACT Purpose: To characterize the extracellular vesicle protein cargo in the aqueous humor and plasma of patients with ocular toxoplasmosis. Methods: Aqueous humor and plasma were collected from six patients with active ocular toxoplasmosis and six patients with cataract. Extracellular vesicles were isolated, and western blotting and mass spectrometry were performed for protein analysis. Results: All plasma samples from patients with ocular toxoplasmosis and cataract were positive for the tetraspanins CD63 and TSG101. However, the aqueous humor from patients with ocular toxoplasmosis was positive only for CD63. Sixty-seven new unreported proteins were identified in the aqueous humor and plasma of patients with the ocular toxoplasmosis and cataract. Of the 67 proteins, 10 and 7 were found only in the cataract and ocular toxoplasmosis groups, respectively. In general, these proteins were involved in immune system activation and retina homeostasis and were related to infections and retina-associated diseases. Conclusion: The distinct protein signatures between ocular toxoplasmosis and cataract may be helpful in the differential diagnosis of ocular toxoplasmosis. However, more studies are needed to better understand the role of these proteins in the pathogenesis of ocular toxoplasmosis.

Seroprevalencia de Toxoplasma gondii y su relación con trastornos mentales en adultos / Seroprevalence of Toxoplasma gondii and its Relationship with Mental Disorders in the Adult Population

El Toxoplasma gondii es un parásito que se encuentra, aproximadamente, en el 30 % de la población humana. Durante los últimos años se ha evidenciado que la infección latente puede ser un factor de riesgo para el desarrollo de trastornos mentales; particularmente para la esquizofrenia, ansiedad, trastornos bipolares y trastornos de conducta. La asociación con los trastornos neuropsiquiátricos pueden explicarse por la influencia que tiene el parásito sobre la expresión de múltiples neurotransmisores; entre ellos la dopamina. Se realizó una búsqueda en las bases de datos PubMed y SciELO de 2015 a 2023, se seleccionaron artículos originales y de revisión de revistas científicas internacionales, en idiomas inglés y español con el objetivo de describir la relación entre la seroprevalencia de T. gondii y el desarrollo de trastornos mentales en población adulta. Existe relación entre los trastornos mentales en la población adulta con la infección por Toxoplasma gondii y este aumenta la posibilidad de desarrollar esquizofrenia y depresión en individuos sin historial previo, y que podría exacerbar cuadros psiquiátricos previos con dificultad en el tratamiento. Sin embargo, no todos los datos estadísticos establecen una relación directa, algunos estudios demuestran una asociación, ciertos datos son discordantes, lo que abre una puerta para futuras investigaciones.

Toxoplasma gondii is a parasite that is found in approximately 30 % of the human population. In recent years, it has been shown that latent infection can be a risk factor for the development of mental disorders; particularly schizophrenia, anxiety, bipolar disorders, and conduct disorders. The association with neuropsychiatric disorders can be explained by the influence of the parasite on the expression of multiple neurotransmitters; among them, dopamine has received the most attention. A narrative bibliographic review article was done with the search of original and review articles in international scientific journals, in English and Spanish listing the relationship between the seroprevalence of T. gondii and the development of mental disorders in the adult population. The relationship between mental disorders in the adult population with Toxoplasma gondii infection is present and increases the possibility of developing schizophrenia and depression in individuals with no previous history, including the ability to worsen previous psychiatric conditions, making it difficult for standard management. Not all statistical data establish a direct relationship, some studies show an association and certain data are discordant, which opens a door for future research.

Two-sample Mendelian randomization analysis of the causal relationship between T．gondii infection and encephalitis / 安徽医科大学学报

Objective @#Mendelian randomization analysis was used to explore the causal relationship of T．gondii in- fection and the cyst distribution and inflammation in brain tissue by immunohistochemistry．@*Methods @#Genome- wide association analysis data of T．gondii infection and encephalitis were obtained ，single nucleotide polymor- phisms (SNPs) were selected，Mendelian randomization analysis was conducted by inverse variance weighting，and the causal relationship between T．gondii infection and encephalitis was evaluated by OR value and 95% CI．Quality control was carried out by using heterogeneity test，horizontal multi-efficiency test and leave-one-out sensitivity test. Immunohistochemical staining was performed using brain sections of mice infected with tissue cysts of Wh6 strain for image analysis using Image J software. @*Results @#A total of 29 SNPs were associated with toxoplasmic encephalitis. The results of IVW method suggested that T．gondii infection made encephalitis risk 0. 98 times higher ( OR = 0. 98， 95% CI = 0. 76 to 1. 27) ，indicating no causal relationship between the two．The quality control results suggested that the selected SNPs were stable and reliable．Toxoplasma cysts were distributed in various parts of the brain tis- sue．@*Conclusion @# T．gondii infection and encephalitis are related，but there is no sufficient evidence to prove the causal relationship between the two.

Seroprevalence of the specific antibody against Toxoplasma gondii among patients with hematological diseases / 中国血吸虫病防治杂志

Objective To investigate the seroprevalence of Toxoplasma gondii infections among patients with hematological diseases, so as to provide insights into improving the prognosis and quality of life among patients with hematological diseases. Methods A total of 240 patients with hematological diseases (including 170 patients with hematological tumors and 70 patients with non-tumor hematological diseases) admitted to The Affiliated Hospital of Putian University during the period from January 1, 2021 through October 10, 2023 and 500 healthy volunteers in the hospital during the same period were enrolled. Subjects’ demographics and serum samples were collected, and serum specific IgG and IgM antibodies against T. gondii were detected using the chemiluminescence assay, with any of a positive IgG or IgM antibody defined as a positive T. gondii infection. The seroprevalence of specific IgG and IgM antibodies against T. gondii was compared between patients with hematological diseases and healthy volunteers. Results The mean age (F = 2.034, P > 0.05) and gender distribution (χ2 = 0.462, P > 0.05) were comparable among patients with hematological tumors, patients with non-tumor hematological diseases and healthy volunteers, and there was no significant difference in the proportion of history of cat or dog contacts between patients with hematological diseases and healthy volunteers (χ2 = 0, P > 0.05). The seroprevalence of anti-T. gondii antibody was significantly higher among patients with hematological diseases than among healthy volunteers (15.8% vs. 0.6%; χ2 = 71.902, P < 0.01), and there was a significant difference in the seroprevalence of anti-T. gondii antibody among patients with hematological tumors (18.2%), patients with non-tumor hematological diseases (10.0%) and healthy volunteers (χ2 = 78.327, P < 0.01). The seroprevalence of anti-T. gondii antibody was significantly higher among patients with hematological tumors and non-tumor hematological diseases than among healthy volunteers (both P values < 0.05), while no significant difference was seen in the seroprevalence of anti-T. gondii antibody between patients with hematological tumors and non-tumor hematological diseases (P > 0.05). In addition, the proportion of history of cat or dog contacts was significantly higher among patients with hematological diseases that were positive for serum anti-T. gondii anti-body than among those negative for serum anti-T. gondii antibody (21.1% vs. 5.4%; χ2 = 8.653, P < 0.05). Conclusions There is a high seroprevalene rate of T. gondii infections among hematological diseases, which is significantly greater than that among healthy volunteers.

Preparation and preliminary application of the polyclonal antibody against Toxoplasma gondii dense granule protein 24 / 中国血吸虫病防治杂志

Objective To prepare and characterize the mouse polyclonal antibody against the dense granule protein 24 (GRA24) of Toxoplasma gondii, and explore its preliminary applications. Methods The GRA24 coding sequences of different T. gondii strains were aligned using the MEGA-X software, and the dominant peptide of the GRA24 protein was analyzed with the Protean software. The base sequence encoding this peptide was amplified using PCR assay and ligated into the pET-28a vector, and the generated GRA24 truncated protein was transformed into Escherichia coli BL21. After induction by isopropyl-beta-D-thiogalactopyranoside (IPTG), the expression and purification of the recombinant GRA24 protein was analyzed using sodium dodecyl sulfate - polyacrylamide gel electrophoresis (SDS-PAGE). BALB/c mice were immunized by subcutaneous injection with the purified recombinant GRA24 truncated protein to generate the polyclonal antibody, and the titer of the polyclonal antibody was measured using enzyme linked immunosorbent assay (ELISA). The specificity of the polyclonal antibody was tested using Western blotting, and the intracellular localization of the polyclonal antibody was investigated using immunofluorescence assay (IFA). Results SDS-PAGE showed successful construction of the recombinant expression plasmid, and Coomassie brilliant blue staining showed the generation of the high-purity recombinant GRA24 truncated protein. ELISA measured that the titer of the polyclonal antibody against the GRA24 truncated protein was higher than 1:208 400, and Western blotting showed that the polyclonal antibody was effective to recognize the endogenous GRA24 proteins of different T. gondii strains and specifically recognize the recombinant GRA24 truncated protein. Indirect IFA showed that the GRA24 protein secreted 16 hour following T. gondii invasion in host cells. Conclusions The polyclonal antibody against the T. gondii GRA24 protein has been successfully prepared, which has a widespread applicability, high titers and a high specificity. This polyclonal antibody is available for Western blotting and IFA, which provides the basis for investigating the function of the GRA24 protein.

Preliminary observation on the development and dynamic changes of chronic toxoplasmosis in mice / 中国血吸虫病防治杂志

Objective To investigate the development and dynamic changes of cysts in the brain of mice following infection with different forms of Toxoplasma gondii, so as to provide insights into for toxoplasmosis prevention and control. Methods ICR mice at ages of 6 to 8 weeks, each weighing 20 to 25 g, were intraperitoneally injected with tachyzoites of the T. gondii PRU strain at a dose of 1 × 105 tachyzoites per mouse, orally administered with cysts at a dose of 20 oocysts per mouse or oocysts at a dose of 200 oocysts per mouse for modeling chronic T. gondii infection in mice, and the clinical symptoms and survival of mice were observed post-infection. Mice were orally infected with T. gondii cysts at doses of 10 (low-dose group), 20 (medium-dose group), 40 cysts per mouse (high-dose group), and the effect of different doses of T. gondii infections on the number of cysts was examined in the mouse brain. Mice were orally administered with T. gondii cysts at a dose of 20 cysts per mouse, and grouped according to gender (female and male) and time points of infections (20, 30, 60, 90, 120, 150, 180 days post-infection), and the effects of gender and time points of infections on the number of cysts was examined in the mouse brain. In addition, mice were divided into the tachyzoite group (Group T), the first-generation cyst group (Group C1), the second-generation cyst group (Group C2), the third-generation cyst (Group C3) and the fourth-generation cyst group (Group C4). Mice in the Group T were intraperitoneally injected with T. gondii tachyzoites at a dose of 1 × 105 tachyzoites per mouse, and the cysts were collected from the mouse brain tissues 30 days post-infection, while mice in the Group C1 were orally infected with the collected cysts at a dose of 30 cysts per mouse. Continuous passage was performed by oral administration with cysts produced by the previous generation in mice, and the effect of continuous passage on the number of cysts was examined in the mouse brain. Results Following infection with T. gondii tachyzoites, cysts and oocysts in mice, obvious clinical symptoms were observed on days 6 to 13 and mice frequently died on days 7 to 12. The survival rates of mice were 67.0%, 87.0% and 53.0%, and the mean numbers of cysts were (516.0 ± 257.2), (1 203.0 ± 502.0) and (581.0 ± 183.1) in the mouse brain (F = 11.94, P < 0.01) on day 30 post-infection with T. gondii tachyzoites, cysts and oocysts, respectively, and the numbers of cysts in the brain tissues were significantly lower in mice infected with T. gondii tachyzoites and oocysts than in those infected with cysts (all P values < 0.01). The survival rates of mice were 87.0%, 87.0% and 60.0%, and the mean numbers of cysts were (953.0 ± 355.5), (1 084.0 ± 474.3) and (1 113.0 ± 546.0) in the mouse brain in the low-, medium- and high-dose groups on day 30 post-infection, respectively (F = 0.42, P > 0.05). The survival rates of male and female mice were 73.0% and 80.0%, and the mean numbers of cysts were (946.4 ± 411.4) and (932.1 ± 322.4) in the brain tissues of male and female mice, respectively (F = 1.63, P > 0.05). Following continuous passage, the mean numbers of cysts were (516.0 ± 257.2), (1 203.0 ± 502.0), (896.8 ± 332.3), (782.5 ± 423.9) and (829.2 ± 306.0) in the brain tissues of mice in the T, C1, C2, C3 and C4 groups, respectively (F = 4.82, P < 0.01), and the number of cysts was higher in the mouse brain in Group 1 than in Group T (P < 0.01). Following oral administration of 20 T. gondii cysts in mice, cysts were found in the moues brain for the first time on day 20 post-infection, and the number of cysts gradually increased over time, peaked on days 30 and 90 post-infection and then gradually decreased; however, the cysts were still found in the mouse brain on day 180 post-infection. Conclusions There is a higher possibility of developing chronic T. gondii infection in mice following infection with cysts than with oocysts or tachyzoites and the most severe chronic infection is seen following infection with cysts. The number of cysts does not correlate with the severity of chronic T. gondii infection, and the number of cysts peaks in the mouse brain on days 30 and 90 post-infection.

Evaluation of nitazoxanide in the treatment of experimental murine neurotoxoplasmosis

ABSTRACT Toxoplasmosis is a widespread zoonotic disease that poses significant public health concern globally, with neurotoxoplasmosis being a severe complication associated with high mortality rates. The standard therapy for neurotoxoplasmosis involves a combination of sulfadiazine and pyrimethamine, which, despite its efficacy, is often limited by adverse effects leading to treatment discontinuation. This study aimed to evaluate the in vivo efficacy of nitazoxanide in treating neurotoxoplasmosis in mice infected with the Me49 strain. The study comprised two groups: Group I, including subgroups of uninfected, infected and treated with saline, and infected and untreated mice; and Group II, comprising infected mice treated with nitazoxanide at 100 mg/kg/day, nitazoxanide at 150 mg/kg/day, and pyrimethamine combined with sulfadiazine. After 14 days of treatment, the mice were euthanized for organ collection. Histopathological examination of the brains revealed that the highest dose of nitazoxanide reduced parasitic load and cerebral hemorrhages. Biochemical and histopathological analyses of liver and kidney tissues demonstrated toxicological profiles comparable to pyrimethamine and sulfadiazine. However, despite showing efficacy and similar toxicity levels, nitazoxanide treatment was less effective regimen in controlling neurotoxoplasmosis in this experimental model compared to the pyrimethamine and sulfadiazine. Thus, while nitazoxanide presents potential in neurotoxoplasmosis treatment, pyrimethamine combined with sulfadiazine remains the preferred therapeutic choice based on better efficacy observed in this study.

Evaluation of different cut-off points for IgG avidity and IgM in the diagnosis of acute toxoplasmosis in pregnant women participating in a congenital toxoplasmosis screening program

ABSTRACT The main social impact of toxoplasmosis stems from its ability to be vertically transmitted. Postnatally acquired infection is generally asymptomatic in approximately 70-90% of cases, making diagnosis often dependent on laboratory tests using serological methods to search for anti-T. gondii antibodies. This study aimed to investigate the ability of the VIDAS TOXO IgG avidity and VIDAS TOXO IgM assays to confirm recent toxoplasmosis. In total, 341 pregnant women with suspected acute toxoplasmosis were systematically monitored in the Program for Control of Congenital Toxoplasmosis in Minas Gerais State, Brazil. We conducted an observational analytical-descriptive cross-sectional study and grouped according to clinical and laboratory criteria as having acute or chronic toxoplasmosis. The VIDAS TOXO IgG avidity and VIDAS TOXO IgM assays were evaluated to investigate the capacity to identify acute infection. IgG avidity showed good performance in identifying acute toxoplasmosis when the IgG avidity index was lower than or equal to 0.1. Values greater than or equal to 3.16 according to the TOXO IgM kit were associated with a greater chance of acute infection. These results may contribute to a more adequate diagnosis of acute gestational toxoplasmosis and, consequently, the avoidance of inadequate or unnecessary treatments.

Diagnóstico fetal de toxoplasmosis ocular congénita: a propósito de un caso / Fetal diagnosis of congenital ocular toxoplasmosis: a case report

RESUMEN La toxoplasmosis congénita tiene graves implicancias para el pronóstico del recién nacido, pues puede afectar al cerebro y al ojo con secuelas severas. La toxoplasmosis ocular congénita tiene como lesión activa característica a la retinocoroiditis, que se diagnostica al nacer por medio del fondo de ojo. No existen reportes fetales de la detección de esta lesión por ultrasonido, pero sí de lesiones severas como microftalmia y catarata. Presentamos un caso de toxoplasmosis congénita en el feto de una gestante con VIH sin tratamiento quien al ultrasonido mostró imágenes anormales en el ojo que se correlacionaron con lesiones en vítreo y retina en las imágenes del fondo de ojo al nacer.

ABSTRACT Congenital toxoplasmosis has serious implications for the prognosis of the newborn, as it can affect the brain and the eye with severe sequelae. The characteristic active lesion of congenital ocular toxoplasmosis is chorioretinitis which is diagnosed at birth by fundus examination. There are no fetal reports of detection of this lesion by ultrasound, but there are reports of severe lesions such as microphthalmia and cataract. We present a case of congenital toxoplasmosis in the fetus of a pregnant woman with untreated HIV who showed abnormal images in the eye on ultrasound that correlated with lesions in the vitreous and retina in the fundus images at birth.

Patogénesis de la infección y Manejo Preconcepcional de la infección por T. gondi

La toxoplasmosis es una infección provocada por el parásito unicelular Toxoplasma gondii. Según las encuestas serológicas de la Tercera Encuesta Nacional de Salud y Nutrición en los Estados Unidos, alrededor del 23% de los adolescentes y adultos tienen signos serológicos de infección por T. gondii, de los cuales el 15% son mujeres en edad fértil. Estas infecciones suelen ser asintomáticas o causar síntomas leves en el adulto (como fiebre, malestar general y linfadenopatía), pero la infección en la mujer embarazada puede provocar graves problemas de salud en el feto si se transmite el parásito (toxoplasmosis congénita) y ocasionar secuelas graves en el bebé como coriorretinits, retraso mental, ceguera, sordera sensorineural y epilepsia. No hay evidencia concluyente de que la prueba y el cuidado preconcepcional reduzcan la infección por Toxoplasma gondii o mejoren el tratamiento de las mujeres infectadas. Por otro lado, si se realiza el asesoramiento preconcepcional, las mujeres que dieron positivo pueden estar tranquilas de que no corren riesgo de infección durante el embarazo y las que dieron negativo pueden recibir consejos sobre cómo prevenir la infección. Las mujeres que se infectan durante el embarazo deben recibir tratamiento. Se deben implementar programas educativos y de detección temprana para las embarazadas que sean rentables para reducir el impacto financiero y emocional de esta enfermedad. (provisto por Infomedic International)

Toxoplasmosis is an infection caused by the single-celled parasite Toxoplasma gondii. According to serologic surveys from the Third National Health and Nutrition Survey in the United States, about 23% of adolescents and adults have serologic signs of T. gondii infection, of which 15% are women of childbearing age. These infections are usually asymptomatic or cause mild symptoms in the adult (such as fever, malaise, and lymphadenopathy), but infection in the pregnant woman can cause serious health problems in the fetus if the parasite is transmitted (congenital toxoplasmosis) and cause severe sequelae in the infant such as chorioretinits, mental retardation, blindness, sensorineural deafness, and epilepsy. There is no conclusive evidence that preconception testing and care reduces Toxoplasma gondii infection or improves treatment of infected women. On the other hand, if preconception counseling is performed, women who tested positive can be reassured that they are not at risk of infection during pregnancy and those who tested negative can receive advice on how to prevent infection. Women who become infected during pregnancy should be treated. Cost-effective educational and early detection programs for pregnant women should be implemented to reduce the financial and emotional impact of this disease. (provided by Infomedic International)

Toxoplasmosis en el embarazo: Características epidemiológicas, clínicas y laboratoriales en un centro de referencia

La toxoplasmosis es una zoonosis causada por el protozoarioToxoplasma gondii (T. gondii), de gran impacto en la salud fetal cuando se adquiere durante el embarazo, debido al riesgo de transmisión vertical. Puede producir manifestaciones clínicas en los recién nacidos: coriorretinitis, hidrocefalia, calcificaciones y retardo psicomotor. La detección precoz y la instauración de una terapéutica adecuada son claves para evitar complicaciones asociadas a la transmisión materno fetal. Objetivo: Describir las características clínicas de gestantes con diagnóstico de toxoplasmosis y de los recién nacidos de éstas, durante los años 2018 al 2021 que acudieron al Servicio de Infectología del Instituto de Previsión Social (IPS). Materiales y métodos: Estudio observacional, descriptivo, de corte trasversal, utilizando un registro de datos de pacientes gestantes que acudieron al IPS durante los años 2018 al 2021. Resultados: Se incluyeron 62 gestantes; mediana de edad de 30 años, (21-44 años); 4 (6%) gestantes, realizaron su primera consulta en el primer trimestre, 39 (63%) en el segundo y 19 (31%) en el tercer trimestre. 9 (15%) pacientes fueron clasificadas como seroconversión, y 53 (85%) con sospecha de infección aguda. 55 pacientes fueron sometidas a amniocentesis; 26 (47%) tuvieron resultado de PCR detectable para Toxoplasma gondii en liquido amniótico, y 29 (53%) no detectable. Sólo 19 recién nacidos contaban con serologías para diagnóstico de toxoplasmosis congénita. Entre las complicaciones fetales se encontraron macrocefalia, e ictericia del RN.

Toxoplasmosis is a zoonosis caused by the protozoan Toxoplasma gondii (T. gondii), with a great impact on fetal health when acquired during pregnancy, due to the risk of vertical transmission. It can produce clinical manifestations in newborns: chorioretinitis, hydrocephalus, calcifications and psychomotor retardation. Early detection and the establishment of adequate therapy are key to avoiding complications associated with fetal-maternal transmission. Objective: To describe the clinical characteristics of pregnant women diagnosed with toxoplasmosis and their newborns, during the years 2018 to 2021 who attended the Infectious Diseases Service of the Social Welfare Institute (IPS). Materials and methods: Observational, descriptive, cross-sectional study, using a data registry of pregnant patients who attended the IPS during the years 2018 to 2021. Results: 62 pregnant women were included; median age 30 years, (21-44 years); 4 (6%) pregnant women had their first consultation in the first trimester, 39 (63%) in the second and 19 (31%) in the third trimester. 9 (15%) patients were classified as having seroconversion, and 53 (85%) with suspected acute infection. 55 patients underwent amniocentesis; 26 (47%) had detectable PCR results for Toxoplasma gondii in amniotic fluid, and 29 (53%) undetectable. Only 19 newborns had serology tests for the diagnosis of congenital toxoplasmosis. Among the fetal complications were macrocephaly, and newborn jaundice.

Expression of CD47 and its ligands in pregnant mice infected with Toxoplasma gondii during pregnancy / 中国血吸虫病防治杂志

Objective To investigate the dynamic expression of cluster of differentiation 47 (CD47) and its ligands signaling regulatory protein α (SIRPα) and thrombospondin-1 (TSP-1) in mice infected with Toxoplasma gondii in the second and third trimesters.. Methods C57BL/6J mice (6 to 8 weeks old) were used for modeling T. gondii infection in the first trimester, and the pregnant mice were randomly divided into the normal control and infection groups, of 10 mice in each group. Pregnant mice in the infection group were intraperitoneally injected with 150 T. gondii tachyzoites on gestational day (Gd) 6.5, while pregnant mice in the normal control group were intraperitoneally injected with the same volume of physiological saline at the same time. The uterine and placental specimens were collected from all pregnant mice on Gd12.5 and Gd18.5, and the pregnant outcomes were recorded. The pathological damages of mouse uterine and placental specimens were observed using hematoxylin-eosin (HE) staining on Gd12.5 and Gd18.5. The relative expression of CD47, SIRPα, TSP-1, surface antigen 1 (SAG1), interferon-γ (IFN-γ), interleukin-2 (IL-2), IL-4 and IL-13 mRNA was quantified in mouse uterine and placental specimens using real-time fluorescence quantitative PCR (qPCR) assay, and the CD47, SIRPα, TSP-1 expression was determined in mouse uterine and placental specimens using immunohistochemical staining. Results As compared with those in the normal control group, the pregnant mice in the infection group showed back arching, bristling, trembling and listlessness during pregnancy, and several mice presented virginal bleeding and abortion. Pathological examinations showed inflammatory cell infiltration, congestion and necrosis in uterine and placental specimens of pregnant mice in the infection group, a higher abortion rate of pregnant mice was seen in the infection group than in the normal control group on Gd12.5 (χ2 = 20.405, P < 0.001) and Gd18.5 (χ2 = 28.644, P < 0.001). qPCR assay showed significant differences in the expression of CD47, SIRPα, TSP-1, SAG1, INF-γ, IL-2, IL-4 and IL-13 genes in mouse placental specimens between the normal control and infection groups on Gd12.5 and Gd18.5 [F′ (F) = 37.511, 29.337, 97.343, 53.755, 67.188, 21.145, 8.658 and 13.930, all P values < 0.001]. Higher CD47, SIRPα and TSP-1 gene expression was quantified in mouse placental specimens in the infection group than in the normal control group on Gd12.5 (all P values < 0.01), and lower CD47, SIRPα and TSP-1 gene expression was quantified in the infection group than in the normal control group on Gd18.5 (all P values < 0.001), while higher SAG1 gene expression was detected in placental specimens of pregnant mice in the infection group than in the normal control group on Gd12.5 and Gd18.5 (both P values < 0.01). In addition, higher INF-γ and IL-2 expression and lower IL-4 and IL-13 expression was detected in mouse placental specimens in the infection group than in the normal control group on Gd12.5 and Gd18.5 (all P values < 0.001), and there were significant differences in the CD47, SIRPα, TSP-1, SAG1, INF-γ, IL-2, IL-4 and IL-13 gene expression in uterine specimens of pregnant mice between the normal control and infection groups on Gd12.5 and Gd18.5 [H(F′ and F) = 14.951, 25.977, 18.711, 48.595, 39.318, 14.248 and 15.468, all P values < 0.01], and higher CD47 and TSP-1 expression was detected in mouse uterine specimens in the infection group than in the control group on Gd12.5 and Gd18.5 (all P values < 0.01); however, no significant difference was found in the SIRPα expression (P > 0.05). Higher SAG1 expression was detected in uterine specimens of pregnant mice in the infection group than in the normal control group on Gd12.5 and Gd18.5 (both P values < 0.01), and higher INF-γ and IL-2 gene expression and lower IL-4 and IL-13 gene expression was found in the placental specimens of pregnant mice in the infection group than in the normal control group on Gd12.5 and Gd18.5 (all P values < 0.001). Spearman correlation analysis showed that the CD47 gene expression correlated positively with IFN-γ (rs = 0.735, P < 0.05) and IL-2 (rs = 0.655, P < 0.05) and negatively with IL-4 (rs = −0.689, P < 0.05) and IL-13 expression (rs = −0.795, P < 0.05) in the placental specimens of pregnant mice in the infection group on Gd12.5, and the CD47 gene expression correlated negatively with IFN-γ (rs = −0.745, P < 0.05) and IL-2 expression (rs = −0.816, P < 0.05) and positively with IL-4 (rs = 0.704, P < 0.05) and IL-13 (rs = 0.802, P < 0.05) in the placental specimens of pregnant mice in the infection group on Gd18.5. Immunohistochemical staining showed mild CD47, SIRPα and TSP-1 expression in uterine and placental specimens of pregnant mice in the normal control group on Gd12.5 and Gd18.5, strong CD47, SIRPα and TSP-1 expression in the placental specimens of pregnant mice in the infection group on Gd12.5 and strong CD47 and TSP-1 expression in the uterine specimens of pregnant mice in the infection group on Gd12.5. Conclusions T. gondii infection in the first trimester may cause abnormal expression of CD47 and its ligands SIRPα and TSP-1 in the maternal-fetal interface of pregnant mice in the second and third trimesters, which may be associated with the immune escape of T. gondii at the maternal-fetal interface.

Research progress on the immunological mechanism of toxoplasmosis / 免疫学杂志

Toxoplasma gondii is an obligate intracellular parasite and causes serious harm to human and ani-mal health.In recent years,a large amount of research has been conducted on the immunological mechanism of toxo-plasmosis,especially in the immune privileged regions of the host,such as brain,eyes,and placenta.This review summaries the immunological mechanism required for resistance to toxoplasmosis,which may provide a valuable ref-erence for the diagnosis,treatment,and prevention studies.

Dynamic pathological changes of Toxoplasma cysts in mouse brain during chronic infection / 安徽医科大学学报

Objective@#To investigate the distribution of toxoplasma cysts in the brain of infected mice and the effect of pathological changes on the behavior and neuropsychiatry of the mice during chronic infection with Toxoplasma gondii( T．gondii) ．@*Methods @#Mice were infected with Prugniaud strain of T．gondii by oral gavage．The brain tissues of infected mice were collected on the days of 10，30，40，90，120 and 160 after infection respectively，and the hippocampal hypothalamus，prefrontal lobe ，striatum and cerebellum regions were separated．The number of cysts and neuropathological changes in each infected area were observed and recorded by HE staining．The number of cysts and neuropathological changes in each infected area were observed and recorded. @*Results @#T．gondii infected mice showed symptoms of vertical hair and arched back，which were the most significant on the 40th day，and then gradually recovered with hemiplegia and circling in circles． At each time point ，the number of toxoplasma cysts was the largest in hippocampal hypothalamus，followed by prefrontal lobe and striatum，and the least in cerebellum．The diameter of toxoplasma cysts increased with time．During chronic infection，specific pathological manifestations of toxoplasma encephalitis，such as neuronophagy，were observed in all regions of the brain tissue．The above pathological changes of toxoplasma encephalitis reached the peak on the 40th day，and gradually recovered， and increased to the stimulation peak on the 120th day，and then gradually recovered．@*Conclusion@# The behavioral and neuropsychiatric symptoms of T．gondii during chronic infection were correlated with the localization and distribution of toxoplasma cysts in the brain of infected mice，and showed dynamic changes.

Molecular and serological pattern of Toxoplasma gondii among rural population in four regions of Gabon

Toxoplasma gondii is an obligatory intracellular parasite that causes a zoonotic disease capable of infecting nearly all warm-blooded hosts, including humans. However, reports on the molecular prevalence of T. gondii in humans are rare in Gabon. The present study aimed to evaluate the serological and molecular prevalence of T. gondii among apparently healthy rural populations in four regions of Gabon. This study included six hundred blood samples from the Interdisciplinary Center for Medical Research (CIRMF) bank, including 300 women and 300 men living in 111 villages. Blood samples were screened using enzyme-linked fluorescent assay (ELFA), while buffy coat samples were analyzed using PCR analyses. Of the 600 samples screened, 548 (91.3%) showed IgG antibodies against T. gondii; 11 (2%) had both IgG and IgM. Among the 548 positive samples, 155 (28%) had higher IgG titers (>300 UI/ml), and 49 of them (31.6%) were detected with T. gondii DNA. The present findings on human toxoplasmosis in Gabon suggest that at an older age, reactivation of old infections seems more frequent than new infections, as indicated by the presence of T. gondii using PCR among elevated IgG subjects without IgM. Further studies should be performed to identify the genotypes of T. gondii that infect humans in Gabon.

Molecular and serological diagnosis of toxoplasmosis: a systematic review and meta-analysis

ABSTRACT Toxoplasmosis is an infection of vast worldwide distribution whose etiologic agent is Toxoplasma gondii. This disease can cause problems ranging from mild symptoms to serious conditions, such as encephalitis, miscarriage and blindness. Therefore, it is of utmost importance to perform a diagnosis with reproducible techniques in order to obtain a good prognosis. The aim of this review was to analyze the efficiency of toxoplasmosis diagnostic techniques based on sensitivity and specificity results. Five research platforms in English language were used (Eric, Elsevier, Google Scholar, PubMed and SciELO), which contained data on the diagnosis of toxoplasmosis. The search and selection were performed for studies published prior to June 2021. The search resulted in the inclusion of 13 articles published from 2005 to 2020. The data revealed the use of different samples in the standardization of techniques such as serum, total blood, colostrum and amniotic fluid. The flow cytometry, lateral flow immunoassay and qPCR techniques showed 100% sensitivity, whereas the ELISA, western blotting, qPCR and RE-LAMP techniques achieved 100% specificity. Significantly, the qPCR and LAMP techniques were more accurate when the likelihood ratio was assessed. The meta-analysis identified that ISAGA and western blotting have low sensitivity values and LIASON, ELFA and ELISA, using a silica bioconjugate, also have low specificity values. It was noted that a wide range of methods have high values of sensitivity and specificity. Therefore, the choice of the method will be based on the conditions and its financial viability.

Infección por Toxoplasma gondii y accidentes de tránsito. Evidencias epidemiológicas de una asociación poco conocida

Recientes pesquisas en las que se utilizó la detección de anticuerpos anti-Toxoplasma gondii como herramienta diagnóstica de toxoplasmosis latente, demostraron asociación entre la infección crónica por el parásito y la disminución de funciones cognitivas, las enfermedades psiquiátricas (esquizofrenia, bipolar, trastornos obsesivo-compulsivos), las enfermedades degenerativas (enfermedad de Alzheimer, múltiples esclerosis, enfermedad de Huntington), y cambios de comportamiento (mayor frecuencia de conductas suicidas y, sobre todo, de accidentes de tránsito). En la literatura revisada, varios estudios demostraron seroprevalencias de anticuerpos anti-T. gondii significativamente mayores en grupos de personas involucradas en accidentes de tránsito que las de sus correspondientes grupos control. La no disponibilidad de fármacos adecuados contra los bradizoítos de T. gondii y de vacunas efectivas contra el parásito, además de no posibilitarse la demostración de una posible relación causal, se obstaculizaba la que podría resultar una vía complementaria para el control de los accidentes de tránsito, un problema de la cotidianidad universal de muy adversas consecuencias humanas y sociales. En perspectivas, la superación de estas limitaciones debe recibir una adecuada atención, tanto de las autoridades sanitarias como de la Academia. En esa dirección, el propósito de este documento es contribuir a ganar conciencia sobre la existencia de esa asociación.

Recent investigations, in which the detection of anti-Toxoplasma gondii antibodies has been used as a diagnostic tool for latent toxoplasmosis, have shown an association between chronic infection by the parasite and decreased cognitive functions, psychiatric illnesses (schizophrenia, bipolar disorder, obsessive - compulsive disorders), degenerative diseases (Alzheimer's disease, multiple sclerosis, Huntington's disease) and behavioral changes (greater frequency of suicidal behaviors and, above all, traffic accidents). In the reviewed literature, several studies demonstrated significantly higher seroprevalence of anti-T. gondii in groups of people involved in traffic accidents than in their corresponding control groups. The unavailability of adequate drugs against T. gondii bradyzoites and effective vaccines against the parasite, in addition to not allowing the demonstration of a possible causal relationship, hinders what could be a complementary way to control traffic accidents, a problem of universal daily life with very adverse human and social consequences. In perspective, overcoming these limitations should receive adequate attention, both from the health authorities and from academia. In this direction, the purpose of this document is to contribute to raising awareness of the existence of this association.

Seroprevalencia y factores de riesgo de Toxoplasma gondii en Personas que Viven con VIH/SIDA (PVVS) en el departamento de Cochabamba, Bolivia

Objetivo: determinar la seroprevalencia y los factores de riesgo de infección crónica por T. gondii en personas que viven con VIH/SIDA (PVVS) en el departamento de Cochabamba. Metodología: estudio observacional-descriptivo de corte transversal. Se emplearon 325 muestras de plasma/suero proveniente de pacientes que asistieron a LABIMED entre Julio y agosto del año 2016. La recopilación de datos se realizó en un formulario sociodemográfico. Se emplearon ensayos serológicos cualitativos de Hemaglutinación Indirecta (HAI) e Inmunoflorecencia Indirecta (IFI), este último para confirmación de casos positivos. Adicionalmente se realizó el recuento de Linfocitos T CD4+ por citómetria de flujo para determinar el estado inmunológico de los pacientes que sirve de guía en el tratamiento clínico. Los datos fueron analizados con el programa/software SPSS versión 20. Resultados: la seroprevalencia global de infección crónica por T. gondii en la población de estudio fue del 40%. El consumo de carne poco cocida (OR: 2,85; 95%IC: 1,56-5,22) y la actividad de agricultura/jardinería (OR: 1,7; IC del 95%: 1,07-2,70) fueron factores de riesgo para adquirir la infección crónica por T. gondii. El 45.6% de las PVVS positivos para toxoplasmosis tiene un recuento de Linfocitos T CD4+ < a 200 células/mm3, equivalente a una inmunodeficiencia severa. Conclusión: El estudio muestra una seroprevalencia significativa de infección crónica por T. gondii, además de presentar una inmunodeficiencia severa en PVVS

Objective: To determine the seroprevalence and risk factors for chronic infection by T. gondii in people living with HIV/AIDS (PLHA) in the department of Cochabamba. Methods: observational-descriptive cross-sectional study. 325 samples (n=325) of plasma/serum from patients who attended LABIMED between the months of July to August of the year 2016 were used. Data (age, gender and risk factors) were collected in the sociodemographic form. Qualitative serological tests of Indirect Hemaglutination (HAI) and Indirect Immunoflorescence (IFI) were used the latter for confirmation of positive cases. Additionally, the count of CD4+ T lymphocytes was performed by flow cytometry to determine the immunological status of the patients that serves as a guide in clinical treatment. The data were analyzed with the program/software SPSS version 20. Results: the global seroprevalence of chronic infection by T. gondii in the study population was 40%. Consumption of undercooked meat (AOR: 2.85; 95% CI: 1,56-5,22) and farming/gardening activity (AOR: 1,7; 95% CI: 1,07-2,70) were risk factors for chronic T. gondii infection. 45,6% of people living with the HIV/AIDS virus who are positive for toxoplasmosis have a CD4+ T lymphocyte count <200 cells/ml, equivalent to severe immunodeficiency. Conclusions: the study shows a significant seroprevalence of chronic infection by T. gondii, as well as presenting a high severe immunodeficiency in patients with the HIV/AIDS virus.

Congenital ocular toxoplasmosis in consecutive siblings / Toxoplasmose ocular congênita em irmãos consecutivos

ABSTRACT Toxoplasma gondii infection can cause ocular manifestations after acquired and congenital disease. We report two cases of symptomatic congenital toxoplasmosis with ocular involvement in non-twin siblings, with a 2-year interval between pregnancies. Vertical transmission of toxoplasmosis in successive pregnancies, which was once considered impossible, is now found to be plausible even in immunocompetent subjects.

RESUMO A infecção pelo Toxoplasma gondii pode causar manifestações oculares tanto após a sua forma congênita quanto a sua forma adquirida. Reportamos aqui dois casos de toxoplasmose congênita sintomática com envolvimento ocular em irmãos não gêmeos, com intervalo de 2 anos entre gestações. A transmissão vertical da toxoplasmose em gestações sucessivas, outrora considerada impossível, é um evento plausível mesmo em indivíduos imunocompetentes.

Transmisión vertical de Toxoplasma gondii asociado a la edad gestacional / Vertical transmission of Toxoplasma gondii associated with gestational age

Una de las principales consecuencias de la infección por Toxoplasma gondii en mujeres embarazadas es la transmisión vertical al feto. Aunque es poco frecuente, la toxoplasmosis congénita puede causar enfermedades neurológicas u oculares graves. La infección primaria por T. gondii durante el embarazo puede tener consecuencias peligrosas, como retinocoroiditis, hidrocefalia, calcificaciones cerebrales, encefalitis, esplenomegalia, pérdida de audición, ceguera y muerte. La atención prenatal debe incluir educación sobre la prevención de la toxoplasmosis. Se trata de un estudio observacional, analítico y transversal. Se evaluaron 209 mujeres gestantes e igual número de recién nacidos; 136 de las mujeres embarazadas resultaron con infección aguda positiva a IgM. De estas 51,20% y 64,71% resultaron primoinfectadas según la determinación de IgA e IgG avidez, respectivamente. 20 de los 35 neonatos provenientes de madres primoinfectadas, adquirieron la infección congénita en el tercer trimestre de la gestación. La conciencia sobre la prevención y el control de la toxoplasmosis es baja entre las poblaciones de alto riesgo. Es necesario fortalecer la educación en salud relacionada con la prevención y el control de la toxoplasmosis en las mujeres en edad reproductiva para prevenir la transmisión vertical a sus productos de gestación y evitar los efectos negativos y hasta mortales de la inefcción por el parásito(AU)

One of the main consequences of Toxoplasma gondii infection in pregnant women is vertical transmission to the fetus. Although rare, congenital toxoplasmosis can cause serious neurological or ocular disease. Primary T. gondii infection during pregnancy can have dangerous consequences, including retinochoroiditis, hydrocephalus, cerebral calcifications, encephalitis, splenomegaly, hearing loss, blindness, and death. Prenatal care should include education on the prevention of toxoplasmosis. This is an observational, analytical and cross-sectional study. 209 pregnant women and the same number of newborns were evaluated; 136 of the pregnant women were acutely infected with IgM. Of these, 51.20% and 64.71% were primary infected according to the determination of IgA and IgG avidity, respectively. 20 of the 35 neonates from mothers with primary infection acquired the congenital infection in the third trimester of pregnancy. Awareness of toxoplasmosis prevention and control is low among high-risk populations. It is necessary to strengthen health education related to the prevention and control of toxoplasmosis in women of reproductive age to prevent vertical transmission to their gestational products and avoid the negative and even fatal effects of infection by the parasite(AU)