Research Progress on the Association between Schizophrenia and Toxoplasma gondii Infection.

Toxoplasma gondii( T. gondii or Tg), is an obligatory intracellular parasite with humans as its intermediate hosts. In recent years, significant correlations between T. gondii infection and schizophrenia have been reported, including the possible mediating mechanisms. Currently, mechanisms and hypotheses focus on central neurotransmitters, immunity, neuroinflammation, and epigenetics; however, the exact underlying mechanisms remain unclear. In this article, we review the studies related to T. gondii infection and schizophrenia, particularly the latest research progress. Research on dopamine (DA) and other neurotransmitters, the blood-brain barrier, inflammatory factors, disease heterogeneity, and other confounders is also discussed. In addition, we also summarized the results of some new epidemiological investigations.

The effect of the HMGB1/RAGE/TLR4/NF-κB signalling pathway in patients with idiopathic epilepsy and its relationship with toxoplasmosis.

This study aims to investigate the relationship between toxoplasmosis and this pathway, which may be effective in the formation of epilepsy by acting through the HMGB1/RAGE/TLR4/NF-κB signalling pathway in patients with idiopathic epilepsy. In the study, four different experimental groups were formed by selecting Toxoplasma gondii IgG positive and negative patients with idiopathic epilepsy and healthy controls. Experimental groups were as follows: Group 1: Epilepsy+/Toxo- (E+, T-) (n = 10), Group 2: Epilepsy-/Toxo- (E-, T-) (n = 10), Group 3: Epilepsy-/Toxo+ (E-, T+) (n = 10), Group 4: Epilepsy+/Toxo+ (E+, T+) (n = 10). HMGB1, RAGE, TLR4, TLR1, TLR2, TLR3, IRAK1, IRAK2, IKBKB, IKBKG, BCL3, IL1ß, IL10, 1 L8 and TNFα mRNA expression levels in the HMGB/RAGE/TLR4/NF-κB signalling pathway were determined by quantitative simultaneous PCR (qRT-PCR) after collecting blood samples from all patients in the groups. Statistical analysis was performed by one-way ANOVA followed by LSD post-hoc tests, and p < 0.05 was considered to denote statistical significance. The gene expression levels of HMGB1, TLR4, IL10, IL1B, IL8, and TLR2 were significantly higher in the G1 group than in the other groups (p < 0.05). In the G3 group, RAGE and BCL3 gene expression levels were significantly higher than in the other groups (p < 0.05). In the G4 group, however, IRAK2, IKBKB, and IKBKG gene expression levels were significantly higher than in the other groups (p < 0.05). HMGB1, TLR4, IRAK2, IKBKB, IL10, IL1B, IL1B, and IL8 in this signalling pathway are highly expressed in epilepsy patients in G1 and seizures occur with the stimulation of excitatory mechanisms by acting through this pathway. The signalling pathway in epilepsy may be activated by HMGB1, TLR4, and TLR2, which are considered to increase the level of proinflammatory cytokines. In T. gondii, this pathway is activated by RAGE and BCL3.

Relationship between the serum level, polymorphism and gene expression of IL-33 in samples of recurrent miscarriage Iraqi women infected with toxoplasmosis.

One of the many warm-blooded hosts that toxoplasmosis-causing intracellular protozoan parasite Toxoplasma gondii can infect is humans. Cytokines are crucial to stimulate an effective immune response against T. gondii. Interleukin-33 (IL-33) is a unique anti-inflammatory cytokine that suppresses the immune response. The levels of cytokine gene expression are regulated by genetics, and the genetic polymorphisms of these cytokines play a functional role in this process. Single nucleotide polymorphisms (SNPs) are prognostic indicators of illnesses. This study aimed to determine whether toxoplasmosis interacts with serum levels of IL-33 and its SNP in miscarriage women as well as whether serum levels and IL-33 gene expression are related in toxoplasmosis-positive miscarriage women. Two hundred blood samples from patients and controls were collected from AL-Alawiya Maternity Teaching Hospital and AL-Yarmouk Teaching Hospital in Baghdad, Iraq from 2021 to 2022 in order to evaluate the serum level of IL-33 using ELISA test. For the SNP of IL-33, the allelic high-resolution approach was utilized, and real time-PCR was performed to assess gene expression. The results showed that compared to healthy and pregnant women, recurrent miscarriage with toxoplasmosis and recurrent miscarriage women had lower IL-33 concentrations. Additionally, there were significant differences among healthy women, pregnant women, and women with repeated miscarriage who experienced toxoplasmosis. Furthermore, no differences between patients and controls were revealed by gene expression data. The results revealed that recurrent miscarriage, pregnancy, and healthy women all had a slightly higher amount of the IL-33 gene fold. Additionally, the SNP of IL-33 data demonstrated that there was no significant genetic relationship between patients and controls. Recurrent miscarriage women with toxoplasmosis have showed significant differences from pregnant women in the genotypes GG and AA as well as the alleles A and G. There were notable variations between recurrent miscarriage with and without toxoplasmosis in terms of the genotypes AA and AC. The genotypes GG, AA, and allele A in recurrent miscarriage women with toxoplasmosis and recurrent miscarriage women is a protective factor. Taking together, there was a statistically significant negative correlation between toxoplasmosis and IL-33 gene expression, which calls for more quantitative investigation in order to fully comprehend the interaction of mRNA and protein.

Heligmosomoides bakeri and Toxoplasma gondii co-infection leads to increased mortality associated with changes in immune resistance in the lymphoid compartment and disease pathology.

Co-infections are a common reality but understanding how the immune system responds in this context is complex and can be unpredictable. Heligmosomoides bakeri (parasitic roundworm, previously Heligmosomoides polygyrus) and Toxoplasma gondii (protozoan parasite) are well studied organisms that stimulate a characteristic Th2 and Th1 response, respectively. Several studies have demonstrated reduced inflammatory cytokine responses in animals co-infected with such organisms. However, while general cytokine signatures have been examined, the impact of the different cytokine producing lymphocytes on parasite control/clearance is not fully understood. We investigated five different lymphocyte populations (NK, NKT, γδ T, CD4+ T and CD8+ T cells), five organs (small intestine, Peyer's patches, mesenteric lymph nodes, spleen and liver), and 4 cytokines (IFN©, IL-4, IL-10 and IL-13) at two different time points (days 5 and 10 post T. gondii infection). We found that co-infected animals had significantly higher mortality than either single infection. This was accompanied by transient and local changes in parasite loads and cytokine profiles. Despite the early changes in lymphocyte and cytokine profiles, severe intestinal pathology in co-infected mice likely contributed to early mortality due to significant damage by both parasites in the small intestine. Our work demonstrates the importance of taking a broad view during infection research, studying multiple cell types, organs/tissues and time points to link and/or uncouple immunological from pathological findings. Our results provide insights into how co-infection with parasites stimulating different arms of the immune system can lead to drastic changes in infection dynamics.

Risk factors for toxoplasmosis in people living with HIV in the Asia-Pacific region.

INTRODUCTION: Toxoplasma gondii can cause symptomatic toxoplasmosis in immunodeficient hosts, including in people living with human immunodeficiency virus (PLWH), mainly because of the reactivation of latent infection. We assessed the prevalence of toxoplasmosis and its associated risk factors in PLWH in the Asia-Pacific region using data from the TREAT Asia Human Immunodeficiency Virus (HIV) Observational Database (TAHOD) of the International Epidemiology Databases to Evaluate AIDS (IeDEA) Asia-Pacific. METHODS: This study included both retrospective and prospective cases of toxoplasmosis reported between 1997 and 2020. A matched case-control method was employed, where PLWH diagnosed with toxoplasmosis (cases) were each matched to two PLWH without a toxoplasmosis diagnosis (controls) from the same site. Sites without toxoplasmosis were excluded. Risk factors for toxoplasmosis were analyzed using conditional logistic regression. RESULTS: A total of 269/9576 (2.8%) PLWH were diagnosed with toxoplasmosis in 19 TAHOD sites. Of these, 227 (84%) were reported retrospectively and 42 (16%) were prospective diagnoses after cohort enrollment. At the time of toxoplasmosis diagnosis, the median age was 33 years (interquartile range 28-38), and 80% participants were male, 75% were not on antiretroviral therapy (ART). Excluding 63 out of 269 people without CD4 values, 192 (93.2%) had CD4 ≤200 cells/µL and 162 (78.6%) had CD4 ≤100 cells/µL. By employing 538 matched controls, we found that factors associated with toxoplasmosis included abstaining from ART (odds ratio [OR] 3.62, 95% CI 1.81-7.24), in comparison to receiving nucleoside reverse transcriptase inhibitors plus non-nucleoside reverse transcriptase inhibitors, HIV exposure through injection drug use (OR 2.27, 95% CI 1.15-4.47) as opposed to engaging in heterosexual intercourse and testing positive for hepatitis B virus surface antigen (OR 3.19, 95% CI 1.41-7.21). Toxoplasmosis was less likely with increasing CD4 counts (51-100 cells/µL: OR 0.41, 95% CI 0.18-0.96; 101-200 cells/µL: OR 0.14, 95% CI 0.06-0.34; >200 cells/µL: OR 0.02, 95% CI 0.01-0.06), when compared to CD4 ≤50 cells/µL. Moreover, the use of prophylactic cotrimoxazole was not associated with toxoplasmosis. CONCLUSIONS: Symptomatic toxoplasmosis is rare but still occurs in PLWH in the Asia-Pacific region, especially in the context of delayed diagnosis, causing advanced HIV disease. Immune reconstitution through early diagnosis and ART administration remains a priority in Asian PLWH.

IgG seroprevalence of Toxoplasma gondii and Leishmania infantum in leprosy patients: Implications for screening and management of co-infections.

Parasitic co-infections are common in developing countries and can interfere with leprosy treatment, leading to an increased risk of inflammatory leprosy reactions. This study assessed serum immunoglobulin G (IgG) levels against Toxoplasma gondii and Visceral Leishmaniasis (VL) antigens in 270 leprosy patients from Brazilian states. Regarding the respective cut-offs, the prevalence of IgG seropositivity for T. gondii and VL were 21.05 % and 47.36 % in the leprosy-negative group, and 77.7 % and 52.6 % in the leprosy-positive group. Of the 270 leprosy patients, 158 (58.5 %) presented with inflammatory leprosy reactions. Of those, 72 (59.5 %) had neuritis, 35 (48.6 %) had reverse reactions, and 28 (38.9 %) had ENL in both Brazilian states. Leprosy patients with anti-Leishmania IgG seropositivity were 3.25 times more likely to develop neuritis (95 % C.I.: 1.187 - 9.154; p = 0.019). These findings are particularly relevant for clinical settings where both leprosy and parasitic diseases are prevalent and could provide essential guidance for detecting and addressing complications arising from parasitic co-infections in leprosy patients, thereby improving clinical management strategies.

Toxoplasma gondii infection and high levels of IgE are associated to erythema nodosum leprosy (ENL).

Leprosy is a chronic infectious disease caused by the bacillus Mycobacterium leprae. The disease may evolve for inflammatory reactions, reversal reaction (RR) and erythema nodosum leprosum (ENL), the major cause of irreversible neuropathy in leprosy, which occur in 1 in 3 people with leprosy, even with effective treatment of M. leprae. Leprosy remains persistently endemic in our region where it predominantly affects lowest socioeconomic conditions people, as Toxoplasma gondii infection in the municipality studied. Previously, we have shown T. gondii coinfection as a risk marker for leprosy, mainly in its severe form. This present study assessed whether T. gondii infection is also a risk factor for leprosy reactions and the predictive value of immunoglobulin production prior to development of leprosy reactions. Patients with leprosy (n = 180), co-infected or not with T. gondii, had their serum investigated for levels of IgA, IgE, IgG1, IgG2, IgG3 and IgG4 anti-PGL-1 by ELISA prior to development of leprosy reactions. The serologic prevalence for T. gondii infection was 87.7% in leprosy reaction patients reaching 90.9% in those with ENL. The leprosy reaction risk increased in T. gondii seropositive individuals was two-fold ([OR] = 2.366; 95% confidence interval [CI 95%]: 1.024-5.469) higher than those seronegative, and considering the risk of ENL, this increase was even more evident (OR = 6.753; 95% CI: 1.050-72.85) in coinfected individuals. When evaluated the prediction of anti-PGL-1 immunoglobulin levels for development of leprosy reactions in patients coinfected or not with T. gondii, only the increase IgE levels were associated to occurrence of reactional episodes of leprosy, specifically ENL type, in patients coinfected with T. gondii, compared to those not coinfected or no reaction. Thus, the immunomodulation in co-parasitism T. gondii-M. leprae suggest increased levels of IgE as a biomarker for early detection of these acute inflammatory episodes and thereby help prevent permanent neuropathy and disability in leprosy patients.

Seroprevalence and sociodemographic characteristics of Toxoplasma gondii infection in patients with psychiatric disorders in Malaysia.

Toxoplasma gondii is a neurotropic protozoan parasite that affects neuronal processing in the brain. This study aimed to investigate the prevalence of T. gondii infection in psychiatric disorder patients. We also investigated the potential association between sociodemographic, clinical manifestation, and behavior of Toxoplasma-seropositive patients with psychiatric disorders. Commercial ELISAs (IgG, IgM, and IgG avidity) using serum and PCR using buffy coat were performed on samples from 54 individuals in each of the following groups: patients diagnosed with depressive disorder, bipolar disorder, and schizophrenia, as well as psychiatrically healthy subjects (control group). They were recruited from the Hospital Universiti Sains Malaysia in Kelantan, Malaysia. Of 54 patients with depressive disorder, 24/54 (44.4 %) were seropositive for IgG, and four (16.7 %) were IgG+/IgM+. Among the latter, a high avidity index indicating a past infection was observed in half of the samples (50.0 %), and the other half (50.0 %) showed a low avidity index, indicating a possible recent infection. Meanwhile, 30/54 (55.6 %) patients with bipolar disorder were seropositive for IgG+, five (16.7 %) were IgG+/IgM+, and four of them had a high avidity index, and one had a low avidity index. Patients with schizophrenia showed 29/54 (53.7 %) seropositive for IgG, two of them (6.9 %) were IgG+/IgM+; one of latter had a high avidity index, and one had a low avidity index. Of 54 people in the control group, 37.0 % (20/54) were seropositive for T. gondii IgG antibodies. However, no significant difference was observed in seroprevalence between the control group and each patient group. No PCR-positive results were documented. A Chi-Square and multiple logistic regression showed that age (p = 0.031), close contact with cats/pets (p = 0.033) and contact with soil (p = 0.012) were significantly associated with Toxoplasma seropositivity in patients with psychiatric disorders. Additional research is needed to elucidate the causal relationships and underlying mechanisms.

Seroprevalence of Toxoplasma gondii and Borrelia burgdorferi infections in patients with multiple sclerosis in Poland.

Multiple sclerosis (MS) is a chronic, demyelinating disease of the central nervous system that affects mainly young people. It is believed that the autoimmune process observed in the pathogenesis of MS is influenced by a complex interaction between genetic and environmental factors, including infectious agents. The results of this study suggest the protective role of Toxoplasma gondii infections in MS. Interestingly, high Toxoplasma IgM seropositivity in MS patients receiving immunomodulatory drugs (IMDs) was identified. On the other hand, Borrelia infections seem to be positively associated with MS. Although the interpretation of our results is limited by the retrospective nature of the studies, the results strongly indicate that further experimental and clinical studies are needed to explain the role of infectious agents in the development and pathophysiological mechanisms of MS.

Systematic Review on the Relationship between Toxoplasmosis and Mental Disorders.

BACKGROUND: Toxoplasmosis is a worldwide parasitic zoonosis caused by the protozoan Toxoplasma gondii. In cases of vertical infection, and in immunosuppressed people by the human immunodeficiency virus (HIV) serious clinical conditions may appear, while immunocompetent people do not present symptoms. However, T. gondii infection has been linked to several mental disorders for decades. OBJECTIVE: To substantiate the possible relationship between T. gondii and mental disorders and suggest control and prevention strategies. MATERIAL AND METHODS: A systematic review has been carried out to analyze the relationship between T. gondii exposure (presence of IgG) and the onset of mental disorders in minors and adults. The etiopathogenic mechanisms described by the authors have also been included and the systems of surveillance, prevention and control of infection have been evaluated. RESULTS: Several processes linked to the presence of cysts and the reactivation of the parasite in certain situations produce an immune and inflammatory response. Also, direct and indirect actions on different neurotransmitters. These mechanisms, together with other environmental and genetic factors, would predispose to different psychiatric pathologies. CONCLUSIONS: Due to the limits of the study, no conclusions can be drawn in childhood and adolescence. However, the results of this systematic review show a possible association of schizophrenia, bipolar disorder and compulsive disorder with T. gondii infection in adults. There is a need to improve control, integrated surveillance and extend prevention measures to the entire population.

Alterations in gut microbiota contribute to cognitive deficits induced by chronic infection of Toxoplasma gondii.

Chronic infection with Toxoplasma gondii (T. gondii) emerges as a risk factor for neurodegenerative diseases in animals and humans. However, the underlying mechanisms are largely unknown. We aimed to investigate whether gut microbiota and its metabolites play a role in T. gondii-induced cognitive deficits. We found that T. gondii infection induced cognitive deficits in mice, which was characterized by synaptic ultrastructure impairment and neuroinflammation in the hippocampus. Moreover, the infection led to gut microbiota dysbiosis, barrier integrity impairment, and inflammation in the colon. Interestingly, broad-spectrum antibiotic ablation of gut microbiota attenuated the adverse effects of the parasitic infection on the cognitive function in mice; cognitive deficits and hippocampal pathological changes were transferred from the infected mice to control mice by fecal microbiota transplantation. In addition, the abundance of butyrate-producing bacteria and the production of serum butyrate were decreased in infected mice. Interestingly, dietary supplementation of butyrate ameliorated T. gondii-induced cognitive impairment in mice. Notably, compared to the healthy controls, decreased butyrate production was observed in the serum of human subjects with high levels of anti-T. gondii IgG. Overall, this study demonstrates that gut microbiota is a key regulator of T. gondii-induced cognitive impairment.

Effect of concurrent infection of Helicobacter pylori with Toxoplasma gondii infection on gastric pathology.

BACKGROUND: Toxoplasma gondii (T. gondii) and Helicobacter pylori (H. pylori) are among the most prevalent foodborne parasitic and bacterial infections worldwide. However, the concurrent impact of coinfection on gastric pathology has yet to be studied in depth. The effect of coinfection generally either adds a synergetic or antagonistic impact; we aimed in the current work to assess the impact of T. gondii coinfection on the progression of H. pylori-associated gastric pathology and reporting H. pylori virulent strains. The study was conducted on 82 patients complaining of persistent gastrointestinal symptoms with failed treatment response and prone to endoscopy. They were subjected to stool examination to detect H. pylori antigen, serological screening for latent toxoplasmosis, endoscopy, histopathological examination, and molecular detection of H. pylori virulence strains in gastric biopsies. Out of the 82 patients, 62 patients were positive for H. pylori antigen in stool and 55 patients confirmed positivity by histopathology; out of them, 37 patients had isolated Vac As1 variants, 11 patients had combined Vac As1 and Cag A variants, and 7 patients had combined Vac As1, Cag A and VacAs2 variants. Patients with the combined two or three variances showed significantly deteriorated histopathological features than patients with a single Vac As1 variant (P < 0.05). Latent toxoplasmosis was positive among 35/82 patients. Combined H. pylori and Toxoplasma gondii infection had significantly marked inflammation than patients with isolated infection (P < 0.05). CONCLUSION: Screening for toxoplasmosis among H. pylori-infected patients is recommended as it is considered a potential risk factor for gastric inflammation severity. H. pylori gastric inflammation may be heightened by Toxoplasma coinfection.

Potential genetic polymorphism of matrix metalloproteinase (MMP)-9 in Iranian migraine patients with Toxoplasma gondii infection.

Toxoplasma gondii is an intracellular protozoan parasite that causes neuroinflammation in the brain and a constant need for peripheral leukocyte migration. Matrix metalloproteinase 9 (MMP-9) can play a major role in this neuroinflammation and be implicated in some neurological disorders, such as migraines. Therefore, the genetic polymorphism evaluation of MMP-9 in migraine patients with T. gondii infection was performed. One hundred fourteen migraine patients and 114 healthy controls were evaluated for the presence of anti-Toxoplasma IgG antibodies. Seventy-two migraine patients and 40 healthy controls were randomly selected for assessment of the MMP 9-1562C/T genetic polymorphism. In the preliminary examination, 61 (53.5%) migraine patients and 43 (37.3%) healthy controls were positive for IgG antibodies, with a significant association between T. gondii seropositivity and migraine (OR = 1.90; 95% CI = 1.21-3.223; P = 0.012). Genetic distribution for the polymorphism was not in Hardy-Weinberg equilibrium in cases but showed no significant variation in control groups (P = 0.03 and P = 0.180, respectively). A significant preponderance of the CT + TT genotype was found in migraine subjects compared to controls (P = 0.042) (OR, 1.77, CI, 1.013-2.229). The homozygote muted allele TT had a higher rate in migraine patients (6.9%). There were significant differences in CT + TT genotype between T. gondii positive and negative migraine patients (P = 0.024), but T allele frequencies had no significant variation (OR 1.7 CI, 1.084-2.44 and 0.42 CI, 0.044-3.97, respectively). In conclusion, the results may provide the first evidence for the involvement of the MMP-9 gene polymorphism in the mechanism of migraine pathology following Toxoplasma infection.

Associations between Toxoplasma gondii seropositivity and psychopathological manifestations in schizophrenic patients: A single-center study from Ecuador.

BACKGROUND: Schizophrenia, a complex neuropsychiatric disorder, is believed to be influenced by various factors including environmental exposures. A potential environmental factor is the infection by the obligate intracellular parasitic protozoan, Toxoplasma gondii which affects neurotransmitter levels, which could potentially exacerbate, trigger symptoms of schizophrenia or make them worst. OBJECTIVE: To investigate the association between Toxoplasma gondii seropositivity and psychopathological presentation in persons with schizophrenia in Ecuador. METHODS: This study was conducted at the Neuroscience Institute of Guayaquil, Ecuador. Among 368 inpatients, 104 were selected based on specific inclusion and exclusion criteria. Descriptive statistics captured patient characteristics and mental health outcomes. Logistic regression models estimated the effect of toxoplasmosis on various mental health outcomes, controlling for demographic and health-related variables. RESULTS: 86.5% of participants were seropositive for toxoplasmosis. Toxoplasma-seropositive schizophrenic patients had a lower risk of depression but a significantly higher risk of disorientation. The most prevalent mental health outcomes were Language Impairments (70.2%) and Bizarre Behavior (76.0%). CONCLUSION: Our findings suggest that Toxoplasma gondii seropositivity may have specific effects on mental functions in schizophrenic patients, particularly reducing the risk of depression but increasing the risk of disorientation. Further studies are required to clarify these associations and the potential underlying mechanisms.

Diabetic Retinopathy during pregnancy in Hispanic women with latent Toxoplasma gondii infection.

BACKGROUND: Retinal photography was performed in pregnancy and postpartum in pregnant Hispanic women with latent Toxoplasma gondii (TG) infection in order to screen for characteristic retinal lesions or the particular scars found in people with active T. gondii infection. A comparison group of TG negative women was included in the study but they did not have retinal photography. OBJECTIVE: The goal of the parent study was to assess for adverse pregnancy events and evidence for parasite reactivation in TG positive (TG + ) women, through examination of the eyes for characteristic lesions. Retinal photography, usually at prenatal visits 2 (17 +/- 3.35 weeks) and 3 (26.3+/-1.75) weeks, was done on TG + women. Fifty-six of these women also (43 %) had retinal photography at the postpartum visit. Health and demographic data were obtained at the first prenatal visit for all women. STUDY DESIGN: From the 690 recruited at the first prenatal visit, 128 TG- women and 158 TG + women were enrolled in a prospective study through pregnancy and the postpartum. All TG- women (n = 532) provided data at the first prenatal visit and throughout their pregnancy and birth through the EHR. This allowed comparison of health and outcome data for the TG + compared to a larger number of TG- Hispanic pregnant women. RESULTS: While there was no evidence of ocular toxoplasmosis during pregnancy, there was a surprisingly large number (42 %) of TG + women with diabetic retinopathy (DR). We also observed that TG + women had a 20 % incidence of gestational diabetes mellitus (GDM) compared to 11.3 % in the TG- women (p = 0.01). At postpartum (mean 5.6 weeks), 23 of 30 women with pregnancy DR showed no DR in the postpartum. CONCLUSIONS: No characteristic T. gondii lesions were discovered. Retinal photography serendipitously revealed DR in these T. gondii positive women. It was also found that latent TG infection was associated with increased incidence of GDM. Hispanic pregnant women's increased risk for latent TG infection, GDM and DR are underappreciated. Retinal photography may need to be considered an innovative approach to screening.

Toxoplasma gondii: Seroprevalence and association with childhood brain tumors in Egypt.

BACKGROUND: Childhood brain tumors are a significant global health challenge, yet the etiology of these tumors remains elusive. While research has identified potential risk factors, recent studies have explored the involvement of infectious agents, particularly Toxoplasma gondii (T. gondii), in brain tumor development. METHODS: This study aimed to explore the prevalence of T. gondii infection in children diagnosed with brain tumors and to investigate the potential association between T. gondii infection and childhood brain tumors in Egypt. A total of 64 children with brain tumors and 92 healthy controls were enrolled in this study. Demographics and risk factors data were collected using structured questionnaires. Serological assay using ELISA technique was performed to detect anti-T. gondii antibodies in both cases and control groups. RESULTS: This study revealed a significantly higher seroprevalence of T. gondii infection in brain tumor cases (62.5 %) compared to healthy controls (38 %). Furthermore, a strong association was observed between T. gondii seropositivity and childhood brain tumors (odds ratio: 2.7). Notably, the consumption of unwashed vegetables emerged as a significant risk factor for T. gondii infection in Egypt. Analysis of T. gondii seroprevalence across different subtypes of brain tumors revealed varying rates, with glioma cases displaying a striking 100 % seroprevalence. CONCLUSIONS: These findings support the hypothesis that T. gondii infection may be a risk factor for childhood brain tumors and emphasize the need for further research in this area. The study also highlights the potential implications of control of T. gondii infection for prevention and treatment of childhood brain tumors.

A pre-existing Toxoplasma gondii infection exacerbates the pathophysiological response and extent of brain damage after traumatic brain injury in mice.

Traumatic brain injury (TBI) is a key contributor to global morbidity that lacks effective treatments. Microbial infections are common in TBI patients, and their presence could modify the physiological response to TBI. It is estimated that one-third of the human population is incurably infected with the feline-borne parasite, Toxoplasma gondii, which can invade the central nervous system and result in chronic low-grade neuroinflammation, oxidative stress, and excitotoxicity-all of which are also important pathophysiological processes in TBI. Considering the large number of TBI patients that have a pre-existing T. gondii infection prior to injury, and the potential mechanistic synergies between the conditions, this study investigated how a pre-existing T. gondii infection modified TBI outcomes across acute, sub-acute and chronic recovery in male and female mice. Gene expression analysis of brain tissue found that neuroinflammation and immune cell markers were amplified in the combined T. gondii + TBI setting in both males and females as early as 2-h post-injury. Glutamatergic, neurotoxic, and oxidative stress markers were altered in a sex-specific manner in T. gondii + TBI mice. Structural MRI found that male, but not female, T. gondii + TBI mice had a significantly larger lesion size compared to their uninfected counterparts at 18-weeks post-injury. Similarly, diffusion MRI revealed that T. gondii + TBI mice had exacerbated white matter tract abnormalities, particularly in male mice. These novel findings indicate that a pre-existing T. gondii infection affects the pathophysiological aftermath of TBI in a sex-dependent manner, and may be an important modifier to consider in the care and prognostication of TBI patients.

Aggravation of cognitive impairments in the valproic acid-induced animal model of autism in BALB/c mice infected with Toxoplasma gondii.

PURPOSE: Toxoplasmosis is a disease caused by infection with a type of coccidial protozoan parasite called Toxoplasma gondii. The relationship between toxoplasmosis and cognitive disorders in neurodegenerative diseases has been proven. There is also evidence that children born to Toxoplasma-infected mothers are more likely to develop autism. METHODS: In the present study, Toxoplasma-infected pregnant BALB/c mice were given valproic acid to induce autism in their male offspring, and their social behaviors, learning, and memory were examined. Chronic toxoplasmosis was established in BALB/c mice by intraperitoneal injection of cyst form of T. gondii. To induce autism, 600 mg/kg of valproic acid was injected intraperitoneally into mice on the 12.5th day of pregnancy. The behavioral experiments, such as social interaction, novel object recognition, and passive avoidance tasks, were performed on male offspring at 50 days. RESULTS: Toxoplasma and valproic acid during the embryonic period caused social communication deficits and disrupted recognition memory and avoidance memory in offspring. Our findings showed that administering valproic acid to Toxoplasma-infected mothers exacerbates cognitive disorders in their offspring.

Vascular Endothelial Growth Factor-C Treatment Enhances Cerebrospinal Fluid Outflow during Toxoplasma gondii Brain Infection but Does Not Improve Cerebral Edema.

Cerebral edema frequently develops in the setting of brain infection and can contribute to elevated intracranial pressure, a medical emergency. How excess fluid is cleared from the brain is not well understood. Previous studies have shown that interstitial fluid is transported out of the brain along perivascular channels that collect into the cerebrospinal fluid (CSF)-filled subarachnoid space. CSF is then removed from the central nervous system through venous and lymphatic routes. The current study tested the hypothesis that increasing lymphatic drainage of CSF would promote clearance of cerebral edema fluid during infection with the neurotropic parasite Toxoplasma gondii. Fluorescent microscopy and magnetic resonance imaging was used to show that C57BL/6 mice develop vasogenic edema 4 to 5 weeks after infection with T. gondii. Tracer experiments were used to evaluate how brain infection affects meningeal lymphatic function, which demonstrated a decreased rate in CSF outflow in T. gondii-infected mice. Next, mice were treated with a vascular endothelial growth factor (VEGF)-C-expressing viral vector, which induced meningeal lymphangiogenesis and improved CSF outflow in chronically infected mice. No difference in cerebral edema was observed between mice that received VEGF-C and those that rececived sham treatment. Therefore, although VEGF-C treatment can improve lymphatic outflow in mice infected with T. gondii, this effect does not lead to increased clearance of edema fluid from the brains of these mice.

Catarata congênita nas infecções intrauterinas mais comuns (STORCH): revisão de literatura / Congenital cataract in the most common intrauterine infections (STORCH): a review of the literature

RESUMO Objetivo: O objetivo deste estudo foi revisar os aspectos clínicos e patológicos da catarata congênita secundária às infecções por sífilis, toxoplasmose, rubéola, citomegalovírus e herpes simples. Métodos: Trata-se de uma revisão de literatura, na qual foram incluídos artigos de periódicos indexados às bases de dados PubMed®, Cochrane, Lilacs, Embase e SciELO de 2010 a 2023. Resultados: Foram encontrados 45 artigos, e, após seleção, restaram 9 artigos. Além disso, foram adicionados artigos para enriquecer a discussão. A infecção por sífilis está relacionada a alterações corneanas. O citomegalovírus e a toxoplasmose estão relacionados com a coriorretinite e/ou microftalmia. A rubéola é responsável por causar catarata, glaucoma, microftalmia e retinite em sal e pimenta. Conclusão: Foram abordadas as principais etiologias infecciosas e seu quadro clínico na CC. O melhor tratamento para CC é cirúrgico associado a acompanhamento clínico, mas a prevenção é a maneira mais eficaz de combater a CC de etiologia infecciosa. O diagnóstico precoce e o tratamento efetivo previnem alterações e sequelas visuais irreversíveis. Nesse contexto, mostram-se importantes as ações de políticas públicas para o melhor desfecho clínico e melhor qualidade de vida.

ABSTRACT Objective: To review the clinical and pathological aspects of CC secondary to infections by syphilis, toxoplasmosis, rubella, cytomegalovirus, herpes simplex. Methods: This is a literature review. Articles from journals indexed to PubMed, COCHRANE, LILACS, EMBASE and SCIELO from 2010 to 2023 were included. Results: A total of 45 articles were found, which, after selection, remained in 9 articles. Some articles were included to enrich the discussion in this topic. The infection caused by syphilis is related to corneal changes. Cytomegalovirus and Toxoplasmosis due to chorioretinitis and/or microphthalmia. Rubella is responsible for causing cataracts, glaucoma, microphthalmia, and salt and pepper retinitis. Conclusion: The main infectious etiologies and their clinical status in CC were addressed. The best treatment for CC is surgery associated with clinical follow-up, but prevention is the most effective way to combat CC of infectious etiology. Early diagnosis and effective treatment prevent irreversible visual changes and sequelae. In this context, public policy actions are important for the best clinical outcome and better quality of life.