Involvement of extracellular vesicles in the interaction of hosts and Toxoplasma gondii.

Toxoplasma gondii, the causative agent of toxoplasmosis, is widely distributed. This protozoan parasite is one of the best adapted, being able to infect innumerous species of animals and different types of cells. This chapter reviews current literature on extracellular vesicles secreted by T. gondii and by its hosts. The topics describe the life cycle and transmission (1); toxoplasmosis epidemiology (2); laboratorial diagnosis approach (3); The T. gondii interaction with extracellular vesicles and miRNAs (4); and the perspectives on T. gondii infection. Each topic emphases the host immune responses to the parasite antigens and the interaction with the extracellular vesicles and miRNAs.

A Comprehensive Bibliometric Analysis of Research Trends About Congenital Toxoplasmosis.

OBJECTIVE: Toxoplasma gondii is an obligate intracellular protozoon that infects approximately one-third of the human population. The parasite could transmit from mother to fetus in cases of acute infection during pregnancy and cause complications in the fetus. The bibliometric analysis is a popular research area that evaluates all the studies indexed in particular databases on a subject. METHODS: This article puts forth bibliometric review of the literature on maternal and congenital toxoplasmosis research indexed in the Web of Science database between 1945 and 2024. VOS viewer, Web of Science and MS Office Excel 17 programs were used in the study. RESULTS: The results of the search showed 1476 publications. The countries that most contributed to the literature were France (n=306, 20.73%), the USA (n=229, 15.52%), and Brazil (n=146, 9.89%). The most cited country was also France (n=10271, 35.52%), followed by the USA (n=9113, 31.51%), and England (n=2611, 9.03%). The top three countries by number of citations per document were Denmark (44.88), the USA (39.79) and France (33.57). The five departments with the most publications are Pediatrics (20.26%), General Internal Medicine (18.16%), Infectious Diseases (16.8%), Obstetrics (14.57%), and Immunology (11.86%). Wallon M. (n=57), Peyron F. (n=49), Thulliez P. (n=36) and Vilena I. (n=36) were the leading authors in terms of contribution to the literature. The five most published journals were Pediatric Infectious Disease Journal (3.66%), Journal of Clinical Microbiology (2.78%), Lancet (2.3%), Presse Medicale (1.76%), and American Journal of Obstetrics and Gynecology (1.63%). CONCLUSION: France is one of the countries that pays the most attention to congenital toxoplasmosis and compatible with this, in our study, the country with the highest number of studies on congenital toxoplasmosis was France. It is thought that drawing more attention to this issue and conducting more studies in countries where the disease is common might yield successful results, as in France.

Investigation of Seropositivity of Anti-Toxoplasma gondii Antibodies and Possible Risk Factors in Pregnant Women with Diabetes at Risk.

OBJECTIVE: Toxoplasmosis is a parasitic infection caused by Toxoplasma gondii. Immunocompromised individuals and pregnant women are at risk, with the latter group being susceptible to miscarriages. This study aimed to determine the seropositivity of T. gondii antibodies and potential risk factors in pregnant women diagnosed with diabetes mellitus. METHODS: The research was conducted at the Ankara City Hospital Perinatology Clinic between October 2021 and June 2022. The study included 277 pregnant women diagnosed with diabetes mellitus and 277 healthy pregnant women who had given birth. Retrospective analysis of anti-T. gondii immunoglobulin (Ig)G and IgM levels was performed for patients between January 2020 and February 2022. Participants were administered an informed consent form and a questionnaire. Data were analysed using SPSS 22. RESULTS: Among pregnant women with diabetes, IgG seropositivity was 18.4%, IgM was 0.0%, and IgG+IgM was 0.0%. In healthy pregnant women, IgG seropositivity was 12.3%, IgM was 0.4%, and IgG+IgM was 0.4%. Overall, seropositivity rates were 15.3% for IgG, 0.2% for IgM, and 0.2% for IgG+IgM. The difference between the two groups was statistically significant (p<0.05). Among pregnant women with diabetes, there was a significant statistical difference (p<0.05) in anti-T. gondii IgG seropositivity related to education, employment status, number of pregnancies and live births, history of toxoplasmosis diagnosis in children, previous toxoplasmosis diagnosis, hygiene, nutrition, and social habits. Among healthy pregnant women, significant statistical differences were found (p<0.05) in IgG seropositivity related to age, income, education level, number of pregnancies and live births, previous toxoplasmosis diagnosis, hygiene, nutrition, and social habits. No invasive interventions were performed on infants born to seropositive mothers, and perinatal data were not available. CONCLUSION: The seroprevalence of toxoplasmosis in Ankara appears to be decreasing, but T. gondii infections continue to pose a public health concern and are significant in pregnant women with diabetes mellitus.

Serological and molecular survey of Toxoplasma Gondii in aborted livestock fetuses from Northeast Iran.

BACKGROUND: Toxoplasmosis not only leads to abortion in humans but also in herbivores, which causes significant financial and quality-adjusted life-year losses. The present study aimed to determine the prevalence of toxoplasmosis in aborted fetuses via serological and molecular assays. Moreover, the genotypes of the obtained isolates were detected. METHODS: Serological and molecular methods were used to study aborted fetuses from Bojnourd City, North Khorasan Province, Iran, which included 52 ovines and 16 bovines. Nested PCR of the B1 gene was used to detect parasite DNA in brain tissues. The PCR-RFLP method for the GRA6 gene was used to determine the genotype of T. gondii. RESULTS: Out of 68 aborted fetuses, 16.1% showed the presence of anti-T. gondii IgG. Among these, 11.7% were identified in bovine fetuses and 4.4% in ovine fetuses. Additionally, two (2.94%) samples of ovine tested positive for anti-T. gondii IgM. Our PCR analysis detected parasite DNA in two cases (2.94%) among 11 IgG-positive samples. All obtained isolates belong to type I of T. gondii. CONCLUSION: Infection with Type I of T. gondii during the neonatal period may partly be responsible for abortion and economic losses in livestock farming in our studied region. To understand the molecular epidemiology and genotypes of T. gondii associated with abortion, further evaluation of aborted samples from different geographical locations is necessary.

Inverted U-shaped relationship between serum 25-hydroxyvitamin D concentrations and Toxoplasma gondii infection: a cross-sectional study.

Background: Toxoplasma gondii (T. gondii) is a widespread zoonotic parasite transmitted through contaminated food or water. It poses a significant public health threat, especially to pregnant women and immunocompromised individuals. 25-Hydroxyvitamin D [25(OH)D] plays a critical role in regulating both innate and adaptive immune responses, particularly in its anti-infective capacity. However, the relationship between serum 25(OH)D concentrations and T. gondii infection remains uncertain. Methods: We analyzed the data from the National Health and Nutrition Examination Survey (NHANES) spanning 2009-2014 to explore the association between serum 25(OH)D concentrations and T. gondii infection. Extensive demographic, comorbidity, and dietary data were collected. The status of T. gondii infection was determined using serum anti-IgG antibodies. Serum 25(OH)D levels were measured using ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). In addition, weighted logistic regression and restricted cubic spline analyses were performed. Results: Our analysis included 10,157 participants (mean [SE] age, 45.38 [0.39] years; 49.73% female) who met the inclusion criteria. Serum 25(OH)D levels were categorized into quintiles, with the second quintile serving as the reference group. The final model, adjusted for age, sex, race, education level, poverty income ratio, body mass index, smoking status, hypertension, diabetes, chronic kidney disease, depression, physical activity, alcohol intake, seasonal testing, and dietary vitamin D, revealed the following adjusted odds ratios (ORs) for the quintiles: 0.75 (95% confidence interval [CI]: 0.60-0.93) for the first, 0.87 (95% CI: 0.69-1.10) for the third, 0.75 (95% CI: 0.58-0.95) for the fourth, and 0.66 (95% CI: 0.49-0.91) for the fifth. Additionally, a restricted cubic spline analysis revealed an inverted U-shaped relationship between serum 25(OH)D and T. gondii infection, with an inflection point at approximately 51.29 nmol/L. Odds ratios to the left and right of the inflection point were 1.17 (95% CI: 1.03-1.32) and 0.94 (95% CI, 0.90-0.98) per 10 nmol/L, respectively. Conclusion: Our study uncovers an inverted U-shaped relationship between serum 25(OH)D concentrations and T. gondii infection, with an inflection point around 51.29 nmol/L.

Inflammatory response and parasite regulation in acute toxoplasmosis: the role of P2X7 receptor in controlling virulent atypical genotype strain of Toxoplasma gondii.

Toxoplasmosis is a globally significant disease that poses a severe threat to immunocompromised individuals, especially in Brazil, where a high prevalence of virulent and atypical strains of Toxoplasma gondii is observed. In 1998, the EGS strain, exhibiting a unique infection phenotype, was isolated in Brazil, adding to the complexity of strain diversity. The P2X7 receptor is critical in inflammation and controlling intracellular microorganisms such as T. gondii. However, its genetic variability can result in receptor dysfunction, potentially worsening susceptibility. This study investigates the role of the P2X7 receptor during acute infection induced by the EGS atypical strain, offering insight into the mechanisms of T. gondii infection in this context. We infected the female C57BL/6 (WT) or P2X7 knockout (P2X7-/-) by gavage. The EGS infection causes intestinal inflammation. The P2X7-/- mice presented higher parasite load in the intestine, spleen, and liver. The absence of the P2X7 receptor disrupts inflammatory cell balance by reducing NLRP3, IL-1ß, and Foxp3 expression while increasing IFN-γ expression and production in the intestine. In the liver, P2X7-/- animals demonstrate diminished inflammatory infiltrate within the portal and lobular regions concurrent with an enlargement of the spleen. In conclusion, the infection of mice with the EGS strain elicited immune alterations, leading to acute inflammation and cytokine dysregulation, while the P2X7 receptor conferred protection against parasitic proliferation across multiple organs.

α2,6 sialylation distinguishes a novel active state in CD4+ and CD8+ cells during acute Toxoplasma gondii infection.

Toxoplasmosis is a worldwide parasitosis that is usually asymptomatic; cell-mediated immunity, particularly T cells, is a crucial mediator of the immune response against this parasite. Membrane protein expression has been studied for a long time in T lymphocytes, providing vital information to determine functional checkpoints. However, less is known about the role of post-translational modifications in T cell function. Glycosylation plays essential roles during maturation and function; particularly, sialic acid modulation is determinant for accurate T cell regulation of processes like adhesion, cell-cell communication, and apoptosis induction. Despite its importance, the role of T cell sialylation during infection remains unclear. Herein, we aimed to evaluate whether different membrane sialylation motifs are modified in T cells during acute Toxoplasma gondii infection using different lectins. To this end, BALB/c Foxp3EGFP mice were infected with T. gondii, and on days 3, 7, and 10 post-infection, splenocytes were obtained to analyze conventional (Foxp3-) CD4+ and CD8+ populations by flow cytometry. Among the different lectins used for analysis, only Sambucus nigra lectin, which detects sialic acid α2,6 linkages, revealed two distinctive populations (SNBright and SN-/Dim) after infection. Further characterization of CD4+ and CD8+ SN-/Dim lymphocytes showed that these are highly activated cells, with a TEf/EM or TCM phenotype that produce high IFN-γ levels, a previously undescribed cell state. This work demonstrates that glycan membrane analysis in T cells reveals previously overlooked functional states by evaluating only protein expression.

Toxoplasma gondii Infection of Alzheimer's Disease Mice Reduces Brain Amyloid Density Globally and Regionally.

BACKGROUND: Toxoplasma gondii infection of Alzheimer's disease model mice decreases amyloid ß plaques. We aimed to determine if there is a brain regional difference in amyloid ß reduction in the brains of T. gondii-infected compared to control mice. METHOD: Three-month-old 5xFAD (AD model) mice were injected with T. gondii or with phosphate-buffered saline as a control. Intact brains were harvested at 6 weeks postinfection, optically cleared using iDISCO+, and brain-wide amyloid burden was visualized using volumetric light-sheet imaging. Amyloid signal was quantified across each brain and computationally mapped to the Allen Institute Brain Reference Atlas to determine amyloid density in each region. RESULTS: A brain-wide analysis of amyloid in control and T. gondii-infected 5xFAD mice revealed that T. gondii infection decreased amyloid burden in the brain globally as well as in the cortex and hippocampus, and many daughter regions. Daughter regions that showed reduced amyloid burden included the prelimbic cortex, visual cortex, and retrosplenial cortex. The olfactory tubercle, a region known to have increased monocytes following T. gondii infection, also showed reduced amyloid after infection. CONCLUSIONS: T. gondii infection of AD mice reduces amyloid burden in a brain region-specific manner that overlaps with known regions of T. gondii infection and peripheral immune cell infiltration.

Disseminated toxoplasmosis infection 20 years post kidney transplant.

Kidney transplant recipients are at increased risk of opportunistic infections and malignancy, including space-occupying intracranial lesions. Here, we present a case of a patient presenting with multiple intracranial lesions in the context of a distant history of transplantation. MRI findings were consistent with a large subcortical enhancing lesion. Leading differentials included posttransplant lymphoproliferative disorder and cerebral cryptococcoma. Brain biopsy was undertaken along with PCR testing on tissue detected Toxoplasma gondii and Epstein-Barr virus (EBV) DNA. Cerebral toxoplasmosis was diagnosed based on characteristic histology and negative EBV immunohistochemistry. This case demonstrates the difficulties and complexities in reaching a diagnosis in immunocompromised patients and the importance of brain biopsy.

Alveolin proteins in the Toxoplasma inner membrane complex form a highly interconnected structure that maintains parasite shape and replication.

Apicomplexan parasites possess several specialized structures to invade their host cells and replicate successfully. One of these is the inner membrane complex (IMC), a peripheral membrane-cytoskeletal system underneath the plasma membrane. It is composed of a series of flattened, membrane-bound vesicles and a cytoskeletal subpellicular network (SPN) comprised of intermediate filament-like proteins called alveolins. While the alveolin proteins are conserved throughout the Apicomplexa and the broader Alveolata, their precise functions and interactions remain poorly understood. Here, we describe the function of one of these alveolin proteins in Toxoplasma, IMC6. Disruption of IMC6 resulted in striking morphological defects that led to aberrant invasion and replication but surprisingly minor effects on motility. Deletion analyses revealed that the alveolin domain alone is largely sufficient to restore localization and partially sufficient for function. As this highlights the importance of the IMC6 alveolin domain, we implemented unnatural amino acid photoreactive crosslinking to the alveolin domain and identified multiple binding interfaces between IMC6 and 2 other cytoskeletal IMC proteins-IMC3 and ILP1. This provides direct evidence of protein-protein interactions in the alveolin domain and supports the long-held hypothesis that the alveolin domain is responsible for filament formation. Collectively, our study features the conserved alveolin proteins as critical components that maintain the parasite's structural integrity and highlights the alveolin domain as a key mediator of SPN architecture.

Evaluating the potential of non-immunosuppressive cyclosporin analogs for targeting Toxoplasma gondii cyclophilin: Insights from structural studies.

Toxoplasmosis persists as a prevalent disease, facing challenges from parasite resistance and treatment side effects. Consequently, identifying new drugs by exploring novel protein targets is essential for effective intervention. Cyclosporin A (CsA) possesses antiparasitic activity against Toxoplasma gondii, with cyclophilins identified as possible targets. However, CsA immunosuppressive nature hinders its use as an antitoxoplasmosis agent. Here, we evaluate the potential of three CsA derivatives devoid of immunosuppressive activity, namely, NIM811, Alisporivir, and dihydrocyclosporin A to target a previously characterized cyclophilin from Toxoplasma gondii (TgCyp23). We determined the X-ray crystal structures of TgCyp23 in complex with the three analogs and elucidated their binding and inhibitory properties. The high resolution of the structures revealed the precise positioning of ligands within the TgCyp23 binding site and the details of protein-ligand interactions. A comparison with the established ternary structure involving calcineurin indicates that substitutions at position 4 in CsA derivatives prevent calcineurin binding. This finding provides a molecular explanation for why CsA analogs can target Toxoplasma cyclophilins without compromising the human immune response.

Molecular survey of Toxoplasma gondii B1 gene in pigs from various localities in Korea.

Toxoplasma gondii, a common protozoan parasite, poses significant public health risks due to its potential to cause toxoplasmosis in humans and can be contracted from pigs, which are considered its critical intermediate host. The aim of this study is to evaluate the prevalence of T. gondii in slaughtered pigs for human consumption, emphasizing the zoonotic implications and the need for improved biosecurity and monitoring practices in pig farming. A total of 1,526 pig samples (1,051 whole blood samples and 384 lung tissue samples from the local slaughterhouse and 91 aborted fetus samples from local farms) were collected throughout the whole country of Korea in 2020. Among them, 6 (0.4%) were found to be infected with T. gondii by nested PCR. When compared by sample type, the prevalence of T. gondii was significantly higher in the aborted fetus samples (2.2%, 2/91) than in the blood (0.3%, 3/1,051) and lung tissue samples (0.3%, 1/384). The B1 gene sequence of T. gondii was similar (97.9-99.8%) to that of the other T. gondii isolates. This study represents the first molecular genotyping survey of T. gondii in the lung tissue of fattening pigs and aborted fetuses in Korea. Our findings indicated the importance of adopting preventive measures including the implementation of rigorous farm hygiene protocols and the promotion of public awareness about the risks of consuming undercooked pork. By addressing the gaps in current control strategies and encouraging the One Health approach, this study contributes to the development of more effective strategies to mitigate the transmission of T. gondii from pigs to humans, ultimately safeguarding public health.

The quality and characteristics of bovine sperm are compromised by Toxoplasma gondii antigens, impacting in in vitro bull fertility.

Studies in various species have demonstrated different results on the effects of T. gondii infection on sperm quality. It has also been demonstrated that in some stages of the disease, there is elimination of cellular debris or even the intact parasite in the semen. The present work aimed to evaluate the in vitro effects of the presence of soluble T. gondii antigens in bovine semen on sperm integrity. The spermatozoa were treated with T. gondii antigens in double serial dilutions classified as high, medium and low doses (8, 4, 2 µg/ml) in "TALP-Sperm" and "TALP-Fert" media. The results showed that T. gondii antigens affect sperm motility and mitochondrial activity, and cause changes in sperm chromatin integrity, as well as damage to the sperm membrane and acrosome. Finally, spermatozoa treated with T. gondii antigens were evaluated in the in vitro production of embryos (IVEP). The use of semen contaminated with antigens in IVEP routines did not lead to a decrease in the fertilization of oocytes, as sperm undergo selection before in vitro fertilization, which eliminates the most altered sperm. However, early embryonic development was affected, probably by structural changes that were not eliminated in the selection process. The results demonstrated that the presence of soluble T. gondii antigens in bovine semen alters sperm integrity and vital characteristics for the fertilization process and embryonic development and therefore causes fertility problems in males.

Live-attenuated PruΔgra72 strain of Toxoplasma gondii induces strong protective immunity against acute and chronic toxoplasmosis in mice.

BACKGROUND: Toxoplasma gondii is an intracellular opportunistic pathogenic protozoan that poses serious threats, particularly in immunocompromised individuals. In the absence of a robust prophylactic measure, the mitigation and management of toxoplasmosis present formidable challenges to public health. We recently found that GRA72 plays an important role in parasitophorous vacuole (PV) morphology, growth and virulence of T. gondii. However, whether gra72-deficient strain can be used as a vaccine remains unknown. METHODS: We first examined the attenuated virulence of gra72 gene knockout strain (PruΔgra72) and the parasite load in organs of the infected mice. Subsequently, we evaluated the immune-protective effects of the PruΔgra72 vaccination against challenge with various types of T. gondii tachyzoites and Pru cysts. Furthermore, levels of antibodies and cytokines induced by PruΔgra72 vaccination were examined. Statistical analysis was conducted by Student's t-test or Mantel-Cox log-rank test based on data obtained from three independent experiments with GraphPad Prism 8.0. RESULTS: We found that PruΔgra72 strain exhibited a significantly attenuated virulence even at the highest dose of 5 × 107 tachyzoites in Kunming mice model. The significant decrease of brain cyst burden and parasite load in the organs of the PruΔgra72-infected mice suggested its potentiality as a live-attenuated vaccine. Hence, we explored the protective immunity of PruΔgra72 vaccination against toxoplasmosis. Results showed that vaccination with 5 × 106 PruΔgra72 tachyzoites triggered a strong and sustained Th1-biased immune response, marked by significantly increased levels of anti-T. gondii IgG antibodies, and significantly higher levels of Th1 type cytokines (IL-2, IL-12 and IFN-γ) compared to that of Th2 type (IL-4 and IL-10). Vaccination with 5 × 106 PruΔgra72 tachyzoites in mice conferred long-term protection against T. gondii infection by less virulent tachyzoites (ToxoDB#9 PYS and Pru strains) and Pru cysts, provided partial protection against acute infection by high virulent Type I RH tachyzoites and significantly decreased brain cyst burden of chronically infected mice. CONCLUSIONS: The avirulent PruΔgra72 induced strong protective immunity against acute and chronic T. gondii infection and is a promising candidate for developing a safe and effective live-attenuated vaccine against T. gondii infection.

Trem2/Syk/PI3K axis contributes to the host protection against Toxoplasma gondii-induced adverse pregnancy outcomes via modulating decidual macrophages.

Decidual macrophages residing at the maternal-fetal interface have been recognized as pivotal factors for maintaining normal pregnancy; however, they are also key target cells of Toxoplasma gondii (T. gondii) in the pathology of T. gondii-induced adverse pregnancy. Trem2, as a functional receptor on macrophage surface, recognizes and binds various kinds of pathogens. The role and underlying mechanism of Trem2 in T. gondii infection remain elusive. In the present study, we found that T. gondii infection downregulated Trem2 expression and that Trem2-/- mice exhibited more severe adverse pregnancy outcomes than wildtype mice. We also demonstrated that T. gondii infection resulted in increased decidual macrophages, which were significantly reduced in the Trem2-/- pregnant mouse model as compared to wildtype control animals. We further described the inhibited proliferation, migration, and invasion functions of trophoblast cell by T. gondii antigens through macrophages as an "intermediate bridge", while this inhibition can be rescued by Trem2 agonist HSP60. Concurrently, Trem2 deficiency in bone marrow-derived macrophages (BMDMs) heightened the inhibitory effect of TgAg on the migration and invasion of trophoblast cells, accompanied by higher pro-inflammatory factors (IL-1ß, IL-6 and TNF-α) but a lower chemokine (CXCL1) in T. gondii antigens-treated BMDMs. Furthermore, compelling evidence from animal models and in vitro cell experiments suggests that T. gondii inhibits the Trem2-Syk-PI3K signaling pathway, leading to impaired function of decidual macrophages. Therefore, our findings highlight Trem2 signaling as an essential pathway by which decidual macrophages respond to T. gondii infection, suggesting Trem2 as a crucial sensor of decidual macrophages and potential therapeutic target in the pathology of T. gondii-induced adverse pregnancy.

The linking of toxoplasmosis and schizophrenia.

Toxoplasmosis is caused by Toxoplasma gondii (Nicolle et Manceaux, 1908), a coccidian protist (Apicomplexa). It has a strong predilection for infecting the central nervous system. Researchers have therefore investigated its association with several neurological and psychiatric disorders, including Alzheimer's disease, attention-deficit hyperactivity disorder, autism, bipolar disorder, cerebral palsy, depression, Guillain-Barre syndrome, multiple sclerosis, obsessive compulsive disorder, Parkinson's disease, personality disorders, and schizophrenia. Among these disorders the strongest evidence for a role of T. gondii exists for psychosis in general and schizophrenia in particular. This paper reviews the origins of this association, briefly summarises the current evidence in support, and discusses future research strategies.

Trends of Toxoplasma gondii and common transfusable venereal infections among blood donors in Menoufia Province, Egypt.

Blood transfusion has a hazard of transmission of many pathogens, including Toxoplasma gondii (T. gondii) and other venereal infections. It is crucial to conduct epidemiological surveillance to detect the prevalence of these pathogens. The study aimed to assess the seroprevalence of T. gondii and common transfusable venereal infections among healthy blood donors in Menoufia Province, Egypt, and identify associated risk factors. Four hundred twenty individuals were recruited between January and April 2023 for cross-sectional descriptive research from the blood banks of Menoufia University medical hospitals. Collected blood samples were screened for anti-T. gondii IgM and IgG, HBsAg, anti-HCV antibodies, HIV p24 antigen and anti-HIV antibodies, and anti-Treponema pallidum antibodies. 46 (11.0%) and 22 donors (5.2%) individuals tested positive for anti-T. gondii IgG with a 95% CI (8.3-14.6) and IgM with a 95% CI (3.5-8.1), respectively, while one patient (0.2%) was positive for both antibodies. Regarding venereal infections, 12 (2.9%) were positive for HBV, 6 (1.4%) were positive for HCV, 7 (1.7%) were positive for HIV, and none of the tested population showed positivity for syphilis. Female gender, consumption of raw meat, agricultural environment, poor awareness about T. gondii, and blood group type (especially AB and O groups) were identified as independent risk factors for T. gondii infection. The study highlights the importance of testing blood donors for T. gondii and common transfusable venereal illnesses. Starting health education programs and preventative measures, such as suitable meat handling and cleanliness practices, is critical for minimizing the occurrence of these illnesses. Larger-scale additional study is advised to confirm these results and provide guidance for public health initiatives.

PP1 phosphatase controls both daughter cell formation and amylopectin levels in Toxoplasma gondii.

Virulence of apicomplexan parasites is based on their ability to divide rapidly to produce significant biomass. The regulation of their cell cycle is therefore key to their pathogenesis. Phosphorylation is a crucial posttranslational modification that regulates many aspects of the eukaryotic cell cycle. The phosphatase PP1 is known to play a major role in the phosphorylation balance in eukaryotes. We explored the role of TgPP1 during the cell cycle of the tachyzoite form of the apicomplexan parasite Toxoplasma gondii. Using a conditional mutant strain, we show that TgPP1 regulates many aspects of the cell cycle including the proper assembly of the daughter cells' inner membrane complex (IMC), the segregation of organelles, and nuclear division. Unexpectedly, depletion of TgPP1 also results in the accumulation of amylopectin, a storage polysaccharide that is usually found in the latent bradyzoite form of the parasite. Using transcriptomics and phospho-proteomics, we show that TgPP1 mainly acts through posttranslational mechanisms by dephosphorylating target proteins including IMC proteins. TgPP1 also dephosphorylates a protein bearing a starch-binding domain. Mutagenesis analysis reveals that the targeted phospho-sites are linked to the ability of the parasite to regulate amylopectin steady-state levels. Therefore, we show that TgPP1 has pleiotropic roles during the tachyzoite cell cycle regulation, but also regulates amylopectin accumulation.

Seroprevalence and age-related susceptibility of TORCH infections in childbearing age women: A 5-year cross-sectional retrospective study and a literature review.

BACKGROUND: Serodiagnosis of TORCH infections should be performed in pre-pregnancy and reproductive-age women to prevent vertical transmission. Herein, we conducted a 5-year cross-sectional retrospective study in childbearing age women to provide prevalence data. Also, stratifying the cohort into three age groups, we identified those most susceptible to acute TORCH infections. METHODS: Between 2019 and 2023, serum samples from 2286 childbearing age women attending the "R. Dulbecco" University Hospital of Catanzaro were collected. Screening for TORCH pathogens, such as: Toxoplasma gondii (TOX), Cytomegalovirus (CMV), Rubella Virus (RUB), Parvovirus B19 (ParvoB19), Herpes Simplex Virus types 1 and 2 (HSV1, HSV2) and Treponema pallidum was carried out using serological tests. Chemiluminescent immunoassay was performed to detect TOX, CMV and ParvoB19 Immunoglobulin M (IgM) and Immunoglobulin G (IgG) antibodies, while Enzyme Linked Fluorescent Assay was performed to detect RUB IgM and IgG antibodies and CMV and TOX IgG Avidity. Enzyme Linked Immunosorbent Assay was performed to detect HSV1 IgG, HSV2 IgG, HSV1/2 IgM, T. pallidum total antibodies and RUB IgG Avidity. Binomial logistic regression models were developed to compare seroprevalence rates among different age groups. RESULTS: The highest immunological protection was observed for RUB infection (87 %), probably associated with vaccination practice, followed by HSV1 and CMV (82 % and 63 %). The 16-25 year age group results as the most susceptible to acute infections as demonstrated by odds of CMV IgM positivity (primary infection) which decreased with age. CONCLUSIONS: The TORCH serological screening program should be implemented in women before pregnancy to formulate strategies for serological screening of childbearing age women and guiding clinicians in making decisions.

Metagenomic analysis of atheroma plaques for identification of microorganisms indicates presence of Toxoplasma gondii as a possible etiological agent.

BACKGROUND: Cardiovascular diseases (CVDs) are the leading cause of death worldwide. Vital organs like the heart are affected by the occlusion of blood vessels due to atherosclerotic plaque formation. However, the role of infectious agents has always been an essential subject of investigation. This study investigated the presence of microorganisms, including nanobacteria, in atherosclerotic plaques removed from human carotid arteries by microbiological and metagenomic examination. METHODS: Atheroma plaque samples were obtained from 20 patients with carotid artery stenosis who had atherectomy by surgery or percutaneous intervention. Nanobacteria were grown by culturing homogenates of the atheroma plaques. Whole genome sequencing was done for samples. Because of the high percentage of Toxoplasma gondii (T. gondii) DNA, PCR investigation was applied to detect T. gondii DNA in the samples. RESULTS: A molecular analysis of nanobacteria revealed them to be made of human proteins, supporting the theory that they are not living organisms. According to sequencing results, samples showed that more than 50 % of the metagenomic sequences belonged to Toxoplasma gondii. PCR investigation indicated that T. gondii DNA was positive in 8 (40 %) of 20 plaques. CONCLUSIONS: Further evidence regarding the role of T. gondii in the etiology of plaque formation may help determine the strategy for prevention and treatment of infections in preventing atheroma plaque formation in the future.