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.

Toxoplasma gondii DNA in Tissues of Anadromous Arctic Charr, Salvelinus alpinus, Collected From Nunavik, Québec, Canada.

BACKGROUND: Toxoplasma gondii is a very common zoonotic parasite in humans and animals worldwide. Human seroprevalence is high in some regions of Canada's North and is thought to be associated with the consumption of traditionally prepared country foods, such as caribou, walrus, ringed seal and beluga. While numerous studies have reported on the prevalence of T. gondii in these animals, in the general absence of felid definitive hosts in the North there has been considerable debate regarding the source of infection, particularly in marine mammals. It has been proposed that fish could be involved in this transmission. AIMS: The objectives of the present study were to perform a targeted survey to determine the prevalence of T. gondii DNA in various tissues of anadromous Arctic charr sampled in Nunavik, Québec, and to investigate the possible role of this commonly consumed fish in the transmission of infection to humans and marine mammals in Canada's North. METHODS AND RESULTS: A total of 126 individual Arctic charr were sampled from several sites in Nunavik, and various tissues were tested for the presence of T. gondii DNA using PCR. Overall, 12 out of 126 (9.5%) Arctic charr tested in the present study were PCR-positive, as confirmed by DNA sequencing. Brain tissue was most commonly found to be positive, followed by heart tissue, while none of the dorsal muscle samples tested were positive. CONCLUSIONS: Although the presence of T. gondii DNA in brain and heart tissues of Arctic charr is very intriguing, infection in these fish, and their possible role in the transmission of this parasite to humans and marine mammals, will need to be confirmed using mouse bioassays. Arctic charr are likely exposed to T. gondii through the ingestion of oocysts transported by surface water and ocean currents from more southerly regions where the definitive felid hosts are more abundant. If infection in Arctic charr can be confirmed, it is possible that these fish could play an important role in the transmission of toxoplasmosis to Inuit, either directly through the consumption of raw fish or indirectly through the infection of fish-eating marine mammals harvested as country foods.

Serological and molecular detection of Toxoplasma gondii infection in apparently healthy horses in eastern of Spain.

Toxoplasmosis is one of the most common parasitic zoonoses and represents a significant health risk for humans, especially for immunodeficient patients. The main transmission route is by oral uptake of oocysts and consumption of undercooked meat of infected animals. Different species have been evaluated as possible reservoirs of the parasite, but few studies have been carried out to examine the role of horses in transmission of the disease. Given the proximity of these animals to humans and the widespread consumption of their meat in many countries, including the Mediterranean basin, it is important to determine the prevalence of T. gondii infection in this species. In this study, blood samples from 105 horses were collected and the presence of T. gondii was evaluated by serological and molecular methods. Antibodies against T. gondii of 12 horses (11.43%) were detected by enzyme-linked immunosorbent assay (ELISA), whereas 29 horses (27.62%) showed positive for PCR. Seroprevalence was related to use of the animals, being higher in horses used for dressage than in others. Purebreds had higher seroprevalence than crossbred animals. No differences between breed, sex or age were found. The results of this study confirm the presence of T. gondii infection in horses, highlighting the need to analyse the meat of this species before human consumption and to control of this infection in horses, as they could be an important reservoir of this zoonotic parasite.

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.

A Rare Modality of Concurrent Cryptococcal and Tubercular Meningitis in a Patient Living With HIV.

Patients with Human Immunodeficiency Virus/Acquired Immunodeficiency Syndrome (HIV/AIDS) and a low CD4 count have decreased humoral and cellular immunity, predisposing them to opportunistic infections. Opportunistic infections are one of the main causes of morbidity and mortality in immunocompromised individuals due to impaired immune systems, particularly in persons living with HIV/AIDS. Common opportunistic infections in patients living with HIV include bacterial infections such as Mycobacterium tuberculosis and Mycobacterium avium complex (MAC); viral infections such as cytomegalovirus (CMV) and herpes simplex virus 1 (HSV-1); fungal infections such as Pneumocystis carinii pneumonia (PCP) and cryptococcal meningitis; and parasitic infections such as cryptosporidiosis and toxoplasmosis. Concurrent infection with cryptococcal and tubercular meningitis in patients with HIV is very rare. Here, we present the case of a 48-year-old male living with HIV who presented with complaints of breathlessness, fever, and weight loss and was evaluated and put on antitubercular medications for pulmonary tuberculosis. However, the presence of a continuous headache led us to investigate further. Upon brain imaging and cerebrospinal fluid evaluation, it was determined to be meningitis due to co-infection with Mycobacterium tuberculosis and Cryptococcus neoformans. The patient was treated with antitubercular therapy along with antifungal therapy. He is under regular follow-up without any further events.

Zingiber officinale Ameliorates Acute Toxoplasmosis-Induced Pathology in Mice.

BACKGROUND: Toxoplasma gondii (T. gondii) infects one third of the world's population with significant illness, mainly among immunocompromised individuals and pregnant women. Treatment options for toxoplasmosis are limited which signifies the need for novel, potent, and safe therapeutic options. The goal of this study was to assess the effectiveness of the ethanolic extract of Zingiber officinale (Z. officinale) in treating mice infected with the RH T. gondii strain. MATERIALS AND METHODS: Gas Chromatography/Mass Spectrometry (GC/MS) was used to identify components of ethanolic extract of Z. officinale. A total of 80 mice were randomly allocated into four experimental groups that contained 20 mice each. The first group was left uninfected (uninfected control), while three groups were infected with T. gondii RH virulent strain tachyzoites at 2500 tachyzoites/mouse. One infected group was left untreated (infected, untreated), whereas the other two groups were treated orally with either spiramycin (positive control) or Z. officinale ethanolic extract at doses of 200 mg/kg and 500 mg/kg, respectively for 5 days, starting the day of infection. Ten mice from each group were used to assess mice survival in different groups, whereas the other ten mice in each group were sacrificed on the 5th day post-infectin (dpi) to estimate the treatment efficacy by quantifying liver parasite load, liver function, nitric oxide (NO) production, and levels of antioxidant enzymes. Additionally, histopathological studies were performed to evaluate the therapeutic effect of Z. officinale treatment on toxoplasmosis-induced pathological alterations in liver, brain, and spleen. RESULTS: Treatment with Z. officinale ethanolic extract extended the survival of mice till 9th dpi compared to 7th dpi in infected untreated mice. Higher percentage of mice survived in Z. officinale-treated group compared to spiramycin-treatment group at different time points. Liver parasite loads were significantly lower in Z. officinale extract-treated mice and spiramycin-treated mice compared to infected untreated mice which correlated with significantly lower levels of serum liver enzymes (ALT, AST) and nitric oxide (NO), as well as significantly higher catalase (CAT) antioxidant enzyme activity. Scanning electron microscopy (SEM) examination of tachyzoites from the peritoneal fluid revealed marked damage in tachyzoites from Z. officinale-treated group compared to that from infected untreated mice. Moreover, treatment with Z. officinale ethanolic extract alleviated infection-induced pathological alterations and restored normal tissue morphology of liver, brain, and spleen. CONCLUSION: Our results demonstrated that Z. officinale treatment reduced parasite burden and reversed histopathological and biochemical alterations in acute murine toxoplasmosis. These findings support the potential utility of Z. officinale as a future effective natural therapeutic for toxoplasmosis. Further studies are needed to determine the effective active ingredient in Z. officinale extract that can be further optimized for treatment of toxoplasmosis.

High level of immunoglobulin G targeting mycoplasma or cytomegalovirus in the newborn increases risk of ADHD.

Attention-deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder typically detected in childhood. Although ADHD has been demonstrated to have a strong genetic component, environmental risk factors, such as maternal infections during pregnancy, may also play a role. We therefore measured the immunological response to 5 abundant microorganisms (Toxoplasmosis Gondii, cytomegalovirus (CMV), Herpes Simplex Virus 1, Epstein Barr Virus and mycoplasma pneumoniae) in newborn heel prick samples of 1679 ADHD cases and 2948 matching controls as part of the iPSYCH Danish case-cohort study. We found an association between high anti-CMV (OR 1.30, 95 % CI [1.09,1.55], p = 0.015) and anti-mycoplasma (OR 1.30, 95 % CI [1.07,1.59], p = 0.037) signal and those newborns later being diagnosed with ADHD. The risk estimate remained increased when controlling for ADHD polygenic risk score as well as penicillin prescriptions. We saw a dose-response association with the amount of positive anti-microorganism titers increasing the risk of being diagnosed with ADHD later in life (p = 0.01 for the trend), suggesting that the more activated the immune system is prior to or at birth, the higher the risk is for a later diagnosis with ADHD. If the associations are causal, they emphasize the importance of a healthy life style during pregnancy to reduce the risk of infections when pregnant and the associated risks for the child.

Toxoplasmosis and Chlamydophilosis in Small Ruminant Farms in Cameroon: Knowledge, Attitudes, Practices, and Perception of Zoonotic Risks of Farmers.

Zoonotic abortive diseases represent a significant health and economic risk for national public health. This cross-sectional survey was conducted from April to October 2021 among 200 selected small ruminant farmers in the three northern regions of Cameroon. Data collection was done through questionnaires administered by exchange with the herder, and responses were coded and recorded on an Excel spreadsheet. The data were then analyzed with R software, version 2.13.0. An ANOVA test was used to assess significant differences in mean of Knowledge, Attitudes, Practices, and Perception of zoonotic risks (KAPP) scores between regions. Pearson correlations were used to calculate the association between KAPP scores within regions. Small ruminant farmers surveyed had low mean scores for knowledge of abortive toxoplasmosis and chlamydophilosis (0.1 ± 0.2), desirable attitude (0.32 ± 0.07), appropriate practice (0.36 ± 0.13) in managing abortion, and positive perception of zoonotic risks of toxoplasmosis and chlamydophilosis in small ruminants (0.12 ± 0.33), respectively. KAPP was significantly (P < 0.01) and positively associated with knowledge (r = 0.98) and risk perception (r = 0.99). However, attitudes (r = 0.06), practices (r = 0.05), and risk perception of toxoplasmosis (r = 0.07) and chlamydophilosis (r = 0.08) were not associated with farmers' knowledge. This study revealed significant knowledge gaps, low levels of desired attitudes, and high-risk behavioral practices. These results therefore call for capacity building of health professionals and farmers to better integrate the One Health concept in the management of neglected zoonotic diseases.

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.

Synthesis of ferrocenyl benzimidazole derivatives as novel anti-Toxoplasma gondii agents.

Toxoplasmosis, a disease caused by the apicomplexan parasite Toxoplasma gondii, affects up to one third of the global population. Although immunocompetent individuals rarely experience severe symptoms, those with immunodeficiencies may potentially face fatal disease. The frontline treatments are currently sulphadiazine and pyrimethamine, which suffer from adverse side effects, and lack efficiency in clearing parasite cysts from the muscles and brain of patients. To address the need for novel, more effective, and less toxic treatments, four new ferrocenyl benzimidazole complexes 15-18 were synthesised and evaluated against the ΔKu80:mNeonGreen strain of T. gondii. Complexes 15 and 17 were found to be active with EC50 values of 17.9 and 17.5 µM respectively, with comparable activity to pyrimethamine, which had an EC50 value of 13.8 µM, and less effective than sulphadiazine, which had an EC50 value of 2.56 µM. Additionally, the compounds were found to be relatively non-toxic against HEK 293T and PNT1A human cell lines. Further investigations found that the complexes act by generating reactive oxygen species (ROS) through the ferrocenyl moiety. These complexes show potential for the development of new treatments against Toxoplasmosis.

Recurrent ocular toxoplasmosis is associated with interferon-gamma deficiency possibly due to genetic origin.

OBJECTIVE: Ocular toxoplasmosis (OT) can cause posterior uveitis; causes of recurrent OT are not well understood. We explored clinical, immunological and genetic properties associated with recurrent OT. METHODS AND ANALYSIS: A recurrent OT patient population (n=9) was identified. Clinical history, ophthalmological findings and immunological properties were assessed. B and T cell immunophenotyping including interferon-gamma (IFN-γ) responses were analysed. An analysis of 592 immunodeficiency genes was performed. RESULTS: The patients experienced 2-7 OT episodes (average 3.7). The first episode occurred at an average of 23.8 (SD 10.1) years of age. All patients had anterior uveitis, vitritis and various fundus lesions of OT. The patients had lymphocyte maturation abnormalities; the proportion of naive CD4+CD45RA+CCR7+ T cells was high in 5/9 cases, and the percentage of CD4+CD45RA-CCR7- T effector memory cells was reduced in 7/9 cases. An increased percentage of CD19+CD38lowCD21low activated B cells was observed in 5/9 cases. IFN-γ response was reduced in CD4+ (8.45±4.17 vs 21.27±11.0, p=0.025) and CD8+ (39.0±9.9 vs 18.1±18.1, p=0.017) T cells. Genetic analysis revealed several potentially harmful variants in immunologically active ERCC3, MANBA, IRF4, HAVCR2, CARMIL2, CD247, MPO, C2 and CD40 genes. CONCLUSION: Our recurrent OT cases had deviations in lymphocyte maturation and IFN-γ responses possibly caused by genetic reasons. However, limitations of our study include failure to identify uniform genetic mechanisms. In addition, we cannot rule out the possibility that the immunological abnormalities can be triggered by chronic toxoplasmosis. Despite the limitations, our findings contribute to the understanding of ocular immunity and development of recurrent OT.

Tumefactive Multiple Sclerosis: The Lethal Chameleon.

Tumefactive multiple sclerosis (TMS) is a rare variant of multiple sclerosis that presents with a large demyelinating lesion in the central nervous system, accompanied by peripheral ring-like enhancement, perilesional oedema and mass effect. We report a case of a 59-year-old woman who was admitted to the hospital with a four-day history of somnolence, muscle weakness in her left extremities and ultimately, loss of consciousness. Over the following 48 hours, the patient's condition worsened with progressive consciousness impairment. Although the results of the initial head computed tomography (CT) scan supported the diagnosis of a multifocal ischaemic stroke, toxoplasmosis was proposed as the most credible diagnostic hypothesis by brain magnetic resonance imaging (MRI). Due to the adverse clinical progression following the initiation of targeted therapy and inconclusive investigation, a brain biopsy was performed, which was indicative of active TMS in a subacute phase. The patient was started on plasmapheresis and natalizumab along with corticosteroids, with a very good response. In conclusion, we report a biopsy-proven TMS diagnosis in a patient that clinically mimicked an acute stroke and was radiographically confounded with intracranial toxoplasmosis. It highlights that TMS is an uncommon neurological demyelinating disease that is often misdiagnosed. It also emphasises the importance of establishing an accurate differential diagnosis to promptly initiate aggressive immunosuppressive treatment, which may result in a more favourable prognosis. LEARNING POINTS: Tumefactive multiple sclerosis is an uncommon variant of multiple sclerosis that presents a substantial diagnostic challenge due to its potential to resemble the clinical and radiological characteristics of other central nervous system (CNS) pathologies, including neoplasms, granulomatous diseases, abscesses and vasculitis.Despite the fact that multimodal imaging studies may help narrow the differential diagnosis, a biopsy is often required to reach a definitive diagnosis and should not be delayed.Awareness of this condition among non-neurologists is critical since a timely and accurate diagnosis prompts aggressive immunomodulatory treatments that may delay a second demyelinating event or progression to clinically definite multiple sclerosis.

SARS-CoV-2 seroprevalence in people living with HIV in South Sudan.

Objectives: The burden of SARS-CoV-2 infection in people living with HIV (PLHIV) in South Sudan is unknown. Methods: We conducted a cross-sectional seroprevalence survey of SARS-CoV-2 immunoglobulin (Ig) G antibodies and other diseases of public health importance (strongyloidiasis, toxoplasmosis) in PLHIV in South Sudan during April 1, 2020-April 30, 2022. We used a multiplex SARS-CoV-2 immunoassay to detect IgG antibodies targeting the SARS-CoV-2 spike, receptor binding domain, and nucelocapsid (N) proteins, and antigens for other pathogens (Strongyloides stercoralis and Toxoplasma gondii). Results: Among 3518 samples tested, seroprevalence of IgG antibodies to SARS-CoV-2 spike protein and receptor binding domain 591 and nucleocapsid ranged from 1.4% (95% confidence interval [CI]: 0.9-2.1%) in April-June 2020 to 53.3% (95% CI: 49.5-57.1%) in January-March 2022. The prevalence of S. stercoralis IgG ranged between 27.3% (95% CI: 23.4-31.5%) in October-December 2021 and 47.2% (95% CI: 37.8-56.8%) in July-September 2021, and, for T. gondii IgG, prevalence ranged from 15.5% (95% CI: 13.3-17.9%) in April-June 2020 to 36.2% (95% CI: 27.4-46.2%) July-September 2021. Conclusions: By early 2022, PLHIV in South Sudan had high rates of SARS-CoV-2 seropositivity. Surveillance of diseases of global health concern in PLHIV is crucial to estimate population-level exposure and inform public health responses.

Anti-Toxoplasma gondii effects of XYP1-derived peptides and regulatory mechanisms of XYP1.

BACKGROUND: Toxoplasmosis, caused by Toxoplasma gondii , poses serious health issues for humans and animals. Individuals with impaired immune systems are more susceptible to severe toxoplasmosis. Pregnant women infected by T. gondii can face the possibility of birth defects and miscarriages. While pyrimethamine and sulfadiazine are commonly used drugs in clinical practice, concerns over their side effects and resistance are on the rise. A spider peptide XYP1 isolated from Lycosa coelestis had potent anti-T. gondii effects, but it had a high synthesis cost and strong cytotoxicity. METHODS: This study intended to modify XYP1 for producing derived peptides via amino acid truncation and substitution. The anti-T. gondii effect was evaluated by trypan blue staining assay and killing experiment of RH strain tachyzoites. The CCK8 and hemolysis assays were used to compare their safeties. The morphological changes of T. gondii were observed by scanning electron microscope and transmission electron microscope. In addition, the mechanism of XYP1 against T. gondii through RNA-sequencing was further explored. RESULTS: In vivo and in vitro experiments revealed that XYP1-18 and XYP1-18-1 had excellent anti-T. gondii activity with lower cytotoxicity and hemolysis activity than XYP1. XYP1, XYP1-18, and XYP1-18-1 were able to disrupt the surface membrane integrity of T. gondii tachyzoites, forming pores and causing the disruption of organelles. Furthermore, RNA-sequencing analysis indicated that XYP1 could stimulate the host immune response to effectively eliminate T. gondii and lessen the host's inflammatory reaction. CONCLUSIONS: XYP1-18 had lower cytotoxicity and hemolysis activity than XYP1, as well as significantly extending the survival time of the mice. XYP1 played a role in host inflammation and immune responses, revealing its potential mechanism. Our research provided valuable insights into the development and application of peptide-based drugs, offering novel strategies and directions for treating toxoplasmosis.

Seropositivity for Toxoplasma gondii in cats with clinical signs and living in households with women of childbearing age.

Toxoplasmosis caused by Toxoplasma gondii is a protozoal zoonosis with high sanitary risk for pregnant women and immunocompromised people. Felids, including domestic cats, are the only definitive hosts of T. gondii. They shed oocysts which, in the environment, become infectious for a wide range of animals, including humans, acting as intermediate hosts. This study evaluated the frequency of acute toxoplasmosis in domestic cats with compatible clinical signs and living in households with women of childbearing age. Individual serum samples were collected from 150 cats and analyzed for IgM and IgG against T. gondii. Statistical analyses were performed to evaluate associations between seropositivity and potential risk factors. Overall, 31 cats (20.7 %) were seropositive for anti-T. gondii antibodies, i.e. 9 (6.0 %) for IgM, 17 (11.3 %) for IgG and 5 (3.3 %) for both. The cats showed different combinations of clinical pictures. The following statistically significant associations were found: male sex and positivity for IgM and/or IgG (p=0.0248; OR= 0.3537; 95 % CI= 0.1528-0.8675), presence of 2 or more clinical signs and positivity to IgM only (p=0.0003; OR= +infinity; 95 % CI= 3.924 to +infinity), presence of either neurological signs (p=0.0025; OR= 13.30; 95 % CI= 3.409-61.39) or ocular signs (p=0.0228; OR= 5.835; 95 % CI= 1.631-22.37) and positivity to IgM only, presence of gastrointestinal signs and positivity to IgG only (p=0.0083; OR= 5.508; 95 % CI= 1.503-18.54). Male sex also resulted a possible risk factor in the binomial logistic regression (p= 0.011; OR= 3.336; 95 % CI= 1.131-8.44). These results indicate that cats living with women of childbearing age are at risk of infection with T. gondii. The presence of certain clinical signs can be helpful in identifying recent and/or current infections using laboratory analyses. Awareness on toxoplasmosis should be kept high to protect animal and public health.

Combination of trimethoprim-sulfamethoxazole and mesenchymal stem cell therapy to treat toxoplasmic encephalitis after hematopoietic stem cell transplantation: A case report.

Toxoplasmosis, caused by the parasite Toxoplasma gondii, is a life-threatening infection that may occur following hematopoietic stem cell transplantation (HSCT). Toxoplasmic encephalitis (TE) is one of the most severe manifestations of this infection and often results in unsatisfactory therapeutic outcomes, especially regarding neurological damage. Recent studies have demonstrated that human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) can significantly aid in neural repair and remodeling. Furthermore, hUC-MSCs have been shown to reduce the risk of graft-versus-host disease (GVHD) associated with the reduction or discontinuation of immunosuppressive therapy. In this case report, we present a pediatric patient who developed TE as a complication of haploidentical HSCT. The patient received a combined treatment regimen of standard anti-Toxoplasma therapy and adjunctive hUC-MSC therapy. The outcomes were satisfactory. The patient regained consciousness, maintained a stable body temperature, and regained the ability to perform daily activities independently. Additionally, next-generation sequencing revealed a decrease in Toxoplasma DNA sequences in the blood and cerebrospinal fluid to undetectable levels. This case report underscores the potential of hUC-MSCs as a promising therapeutic modality for TE.

Functional Characterization of 11 Tentative Microneme Proteins in Type I RH Strain of Toxoplasma gondii Using the CRISPR-Cas9 System.

Toxoplasma gondii, a pathogenic apicomplexan parasite, infects approximately one third of the world's population and poses a serious threat to global public health. Microneme proteins (MICs) secreted by the microneme, an apical secretory organelle of T. gondii, play important roles in the invasion, motility, and intracellular survival of T. gondii. In this study, we selected 11 genes of interest (GOIs) of T. gondii, tentative MICs predicted to be localized in micronemes, and we used the CRISPR-Cas9 system to construct epitope tagging strains and gene knockout strains to explore the localization and function of these 11 tentative MICs. Immunofluorescence assay showed that nine tentative MICs (TGME49_243930, TGME49_200270, TGME49_273320, TGME49_287040, TGME49_261710, TGME49_205680, TGME49_304490, TGME49_245485, and TGME49_224620) were localized or partially localized in the microneme, consistent with the prediction. However, TGME49_272380 and TGME49_243790 showed different localizations from the prediction, being localized in the endoplasmic reticulum and the dense granule, respectively. Further functional characterization of the 11 RHΔGOI strains revealed that deletion of these 11 GOIs had no significant effect on plaque formation, intracellular replication, egress, invasion ability, and virulence of T. gondii. Although these 11 GOIs are not essential genes for the growth and virulence of tachyzoites of type I RH strain, they may have potential roles in other developmental stages or other genotypes of T. gondii. Thus, further research should be performed to explore the possible role of the nine mics and the other two GOIs in other life cycle stages and other genotypes of T. gondii.