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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., (© 2024. The Author(s).)

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., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

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-1β, 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., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision., (Copyright © 2024 Prado-Rangel, Moreira-Souza, da Silva, Barboza-Araujo, Castro-Junior, Ramos, Takiya, Vommaro and Coutinho-Silva.)

Anti-Toxoplasma gondii antibodies were investigated in 125 Saimiri spp. kept at a research institute. A total of 12% of primates tested positive, all of which were Saimiri sciureus. These results highlight the need to minimize the possibility of this protozoan's circulation, which can lead to fulminant infection in these animals., (© 2024 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Seroprevalence studies on cats are essential for monitoring the occurrence of Toxoplasma gondii infection. The present research investigated anti-T. gondii antibodies, risk factors, clinical signs, hematology and serum biochemistry in cats from different regions of Rio de Janeiro. An overall 18.7% (17/91) of the cats were seroreactive, and age was associated with increased chances of seroprevalence of anti-T. gondii antibodies. Clinical signs, hematology and serum biochemistry parameters did not help achieve an antemortem diagnosis of cat toxoplasmosis. The parasite circulates in cats from three major regions of Rio de Janeiro, and the present data set will contribute to future epidemiological studies in this endemic state of Brazil., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

The present in vitro and in vivo study aimed to fabricate and characterize linalool-zinc oxide nanoparticles (Lin-ZNP) and evaluate their effectiveness against Toxoplasma gondii infection in terms of inflammation, oxidative stress, and pathogenicity. Lin-ZNP was synthesized using an ethanolic solution of polyvinyl alcohol. The anti-Toxoplasma and cytotoxicity activities of Lin-ZNP were investigated, along with its effects on nitric oxide (NO) production, caspase-3 activity, and pro-inflammatory genes. After treating T. gondii-infected mice with Lin-ZNP for 14 days, the number and size of tissue cysts, antioxidant potential, pro-inflammatory cytokines, and T. gondii pathogenicity-related genes were evaluated by real-time polymerase chain reaction and Western blot analysis. The Lin-ZNP composite showed a reduced tendency with an average size of 105 nm. Lin-ZNP significantly reduced the viability of tachyzoites. The obtained selectivity index higher than 10, indicating high specificity for parasites with low cytotoxicity to normal cells. The Lin-ZNP significantly (p < 0.05) increased the production of NO, caspase-3 activity, and the expression levels of pro-inflammatory genes. Lin-ZNP significantly (p < 0.001) decreased the size and number of tissue cysts and caused a significant reduction in the level of malondialdehyde and a considerable increase (p < 0.001) in antioxidant enzymes and their expression genes. Lin-ZNP significantly downregulated both mRNA and protein expression of the inflammation-related markers associated with the TLRs/NF-κB pathway. The expression levels of the T. gondii pathogenicity-related genes were significantly downregulated (p < 0.05). The recent survey indicated that Lin-ZNP manages T. gondii infection by its antioxidant activity and inhibiting the TLRs/NF-κB pathway without toxicity in mice., (© 2024 Wiley‐VCH GmbH.)

Toxoplasma gondii and Neospora caninum infections may be associated with neuromuscular disorders in dogs. The aim of this study was to assess the seroprevalence to these protozoan parasites in dogs with neuromuscular disease from urban areas of Buenos Aires province, Argentina, over a period of 20 years, and to evaluate the association of seropositivity and antibody titres with different variables such as sex, breed and age. For this, a total of 7238 serum samples from urban owned dogs were analysed by the indirect fluorescence antibody test (IFAT) for specific IgG antibodies. The observed seropositivity rates were 35.7 % for T. gondii and 25.7 % for N. caninum. Crossbred dogs had a significantly higher seroprevalence for T. gondii than purebred dogs (41 % vs. 29.3 %), while a trend towards significance was observed for N. caninum, which was slightly higher in purebred dogs (26 % vs. 23.6 %). Seroprevalence for both parasites increased with age and was higher in older animals. Regarding the distribution of specific antibody titres, the most frequent IFAT T. gondii titre found was 100 and for N. caninum it was ≥800. For toxoplasmosis, there was no association with age group, and low titres (50, 100 and 200) predominated in all groups. However, for neosporosis, age and titres were significantly associated for one age group, with dogs under 12 months of age having a higher proportion of high titres (400 and 800). The trend in the seroprevalence for T. gondii is increasing over the years and lower antibody titres predominate in the dogs studied, which may be more related to the presence of chronic infections and not necessarily to the clinical signs of the animals. Despite the generally low titres observed for toxoplasmosis in this study, it is important to highlight the high seroprevalence found in our region, as dogs can act as sentinels of environmental contamination and as indicators of possible human infection. In the case of neosporosis, although the trend in seroprevalence in dogs with signs appears to be decreasing over the years, our work shows that higher antibody titres predominate, and are probably related to the clinical signs presented by the dogs. This study provides the most recent epidemiological data and serological profiles of T. gondii and N. caninum infections in a large number of canine sera from urban areas in Argentina, providing relevant information for clinical veterinarians and epidemiologists in order to understand the circulation of the parasites., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Venturini Maria Cecilia reports financial support was provided by UNLP, FONCyT. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Toxoplasma gondii (T. gondii)-associated polymorphic effector proteins are crucial in parasite development and regulating host anti-T. gondii immune responses. However, the mechanism remains obscure. Here, it is shown that Toxoplasma effector dense granules 4 (GRA4) restricts host IFN-I activation. Infection with Δgra4 mutant T. gondii strain induces stronger IFN-I responses and poses a severe threat to host health. Mechanistically, GRA4 binds to phosphorylated TBK1 to promote TRIM27-catalyzed K48-ubiquitination at Lys251/Lys372 residues, which enhances its recognition by autophagy receptor p62, ultimately leading to TBK1 autophagic degradation. Furthermore, an avirulent Δgra4 strain (ME49Δompdc/gra4) is constructed for tumor immunotherapy due to its ability to enhance IFN-I production. Earlier vaccination with ME49Δompdc/gra4 confers complete host resistance to the tumor compared with the classical ME49Δompdc treatment. Notably, ME49Δompdc/gra4 vaccination induces a specific CD64 + MAR-1 + CD11b + dendritic cell subset, thereby enhancing T cell anti-tumor responses. Overall, these findings identify the negative role of T. gondii GRA4 in modulating host IFN-I signaling and suggest that GRA4 can be a potential target for the development of T. gondii vaccines and tumor immunotherapy., (© 2024 The Author(s). Advanced Science published by Wiley‐VCH GmbH.)

Toxoplasma gondii is a food-borne zoonotic parasite widespread in a variety of hosts, including humans. With a majority of infections in Europe estimated to be meat-borne, pork, as one of the most consumed meats worldwide, represents a potential risk for consumers. Therefore, we aimed to investigate the progress of T. gondii infection and tissue tropism in experimentally infected pigs, using different T. gondii isolates and infectious stages, i.e. tissue cysts or oocysts. Twenty-four pigs were allocated to treatment in four groups of six, with each group inoculated orally with an estimated low dose of either 400 oocysts or 10 tissue cysts of two European T. gondii isolates, a type II and a type III isolate. The majority of pigs seroconverted two weeks post-inoculation. Pigs infected with the type III isolate had significantly higher levels of anti-T. gondii antibodies compared to those infected with the type II isolate. Histopathological exams revealed reactive hyperplasia of the lymphatic tissue of all pigs. Additionally, a selected set of nine tissues was collected during necropsy at 50 dpi from each of the remaining 22 pigs for T. gondii DNA detection by quantitative real-time PCR. A positive result was obtained in 29.8 % (59/139) of tested tissues. The brain was identified as the most frequently positive tissue in 63.6 % (14/22) of the animals. In contrast, liver samples tested negative in all animals. The highest mean parasite load, calculated by interpolating the average Cq values on the standard curve made of ten-fold serial dilutions of the genomic DNA, corresponding to 10 0 to 10 4 tachyzoites/µL, was observed in shoulder musculature with an estimated concentration of 84.4 [0.0-442.5] parasites per gram of tissue. The study highlights the variability in clinical signs and tissue distribution of T. gondii in pigs based on the combination of parasite stages and strains, with type III isolates, particularly oocysts, causing a stronger antibody response and higher tissue parasite burden. These findings suggest the need for further investigation of type III isolates to better understand their potential risks to humans., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Toxoplasmosis is a parasitic zoonosis of key importance in veterinary and public health. This article summarizes the available data (from 2000 to 2023) of exposition to Toxoplasma gondii in wildlife species in Spain based on a systematic bibliographic search, as well as further analysis of its potential relationship with environmental variables, biodiversity, anthropogenic impact on the habitat, and the reported human cases of toxoplasmosis. The overall seroprevalence of T. gondii in carnivorous mammals, birds, ungulate and lagomorph species in Spain was estimated at 69.3 %, 36.4 %, 18.4 %, and 16.2 %, respectively. Among the studies considered, great heterogeneity was observed both between and within taxonomic groups [Cohen's d > 0.8; X 2  = 1039.10, df = 4 (p < 0.01) I 2  = 97 %, r 2  = 1.88, (p < 0.001)] and between and within bioregions [Cohen's d > 0.5; X 2  = 368.59, df = 4 (p < 0.01)]. The results of a generalized linear model explaining T. gondii seroprevalence in wild animals suggest the influence of abiotic variables [wetland (p < 0.001), unvegetated (p < 0.001), isothermality (p < 0.001), and mean temperature during wettest quarter (p < 0.05)] and number of intermediate host species as positively associated with increased exposure of wildlife to T. gondii (p < 0.01). Toxoplasma gondii DNA was detected in both wild birds and wild mammals (range: 0.0-51.2 %) mainly from north-centre, northeast, and central-west of Spain. Regarding hospitalisation rates due to toxoplasmosis in humans, some abiotic variables [permanent crops (p < 0.05) and mean temperature during wettest quarter (p < 0.05)] showed a positive association. Despite certain limitations, this research evidences a substantial gap of knowledge on the implication of wildlife in the life cycle of T. gondii in Spain. This lack of knowledge is particularly evident in areas where the human-livestock-wildlife interface overlaps, preventing us from accurately determining its true distribution in different habitats, as well as its potential direct or indirect implications on public and veterinary health., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

There is a need to reconsider the acceptance of organs from donors considered suboptimal, in the absence of data. Toxoplasma antibody-positive donors (TPD) constitute one such group. The objective of our study was to compare graft survival in deceased donor renal transplant (Tx) recipients, stratified by Toxoplasma IgG status, using the Organ Procurement and Transplantation Network (OPTN) database. A log-linear event history regression model for graft failure categorized by Toxoplasma IgG status, adjusting for confounders was applied to first kidney-only Tx recipients from 2018 to 2022. Of the 51,422 Tx, 4,317 (8.4%) were from TPD. Acute rejection and graft failure (5% each) were similar between groups. Crude graft failure was 7.3 failures per 100 person-years for TPD recipients compared to 6.5 failures per 100 person-years for the Toxoplasma-negative group ( p 0.008). The crude failure rate ratio was 1.14 with an adjusted hazard rate ratio of 1.04 (95% CI: 0.94, 1.15, p 0.39). In renal Tx recipients, TPD graft recipients have comparable survival to Tx from Toxoplasma-negative recipients. While caution and close monitoring of recipients post-Tx for surveillance of disseminated toxoplasmosis are still warranted, our study suggests that patients can be successfully managed using TPD organs., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Butani and Tancredi.)

Toxoplasmosis is a foodborne disease caused by the protozoan Toxoplasma gondii, and transmitted to humans by eating raw or undercooked meat, mainly. Poultry, beef, and pork are the main meats consumed in Peru; despite this, guinea pig meat is also widely consumed. For this reason, the objective of this study was to molecularly detect T. gondii in domestic and wild guinea pigs from the Marangani district in Cuzco, Peru, and identify some risk factors associated with this pathogen. DNA was extracted from the brain tissue samples of guinea pigs (30 domestic and 30 wild), and PCR protocols were used to amplify the internal transcribed spacer (ITS-1) region and a 529 bp fragment from the T. gondii genome. T. gondii DNA was detected in 14 (23.3%) guinea pigs. T. gondii frequency was 33.3% in domestic guinea pigs and 13.3% in wild guinea pigs. Our results demonstrated that guinea pigs represent an important source for T. gondii infection in human populations in this locality., Competing Interests: Declaration of competing interest Not applicable., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Toxoplasmosis is one of the most common zoonotic parasitic diseases worldwide and is caused by Toxoplasma gondii. It is implicated in reproductive disorders in small ruminants. This study aims to determine, for the first time in Algeria, the seroprevalence and associated factors of T. gondii infection in goats. The study was conducted in four regions, Ghardaia, Laghouat and Djelfa, southern Algeria, and Jijel region, northern Algeria. A total of 92 blood samples were collected including 74 females and 18 males. All sera were tested using an enzyme-linked immunosorbent assay (ELISA) to detect the T. gondii antibodies. The presence of anti-T. gondii antibodies was detected in 35 out of 92 goats (38.04%) (95% CI: 31.64%-44.44%) and in all flocks (100%). Risk factors that have a significant influence on the seroprevalence of T. gondii infection are breed, regions, production system, presence of cats, clinics and abortion history. However, variables such as age and gender were note significantly associated with toxoplasma infection in goats. The highest seroprevalences of infection was observed in saanen (52.94%) (p<0.001) and cross-breed race (44%) (p<0.01) in comparison with other breeds. Regarding regions, Jijel and Laghouat were most infected with seroprevalences of 50% (p<0.001) and 40.91% (p<0.01), respectively. Animals in intensive production systems were most infected, showing a seroprevalence of 51.85%, in comparison with extensive (28.13%) and semi-intensive systems (36.36%) (p<0.001). The presence of cats in farms was significantly associated with high seroprevalence (44.64%) (p<0.001). The infection was more prevalent in previously aborted females (50%) than females that had never aborted (3.35%) (p<0.001)and animals that have diarrhoea or poor health (41.67%) were significantly more infected than healthy animals (37.50%) (p<0.01). Seroprevalence in males (38.89%) was very close to those in females (37.84%) (p>0.05). Age-related seroprevalence did not vary significantly (ranged from 36.37% to 40%) between the three age classes. These results indicate that goat toxoplasmosis is widespread in Algeria, and goats may represent a high risk of contamination for humans. This requires more attention during consumption of goat meat., Competing Interests: Declaration of Competing Interest The authors declare that they have no competing interests., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Toxoplasma gondii is the causative agent of toxoplasmosis, a zoonotic disease of worldwide distribution. The aim of this study was to assess the seroprevalence of T. gondii in undergraduate students from Lima, Peru, and to identify the risk factors linked to the infection. For this, serum samples of 100 undergraduate students of the Faculty of Biological Sciences were tested for T. gondii antibodies with a commercially available ELISA. The seroprevalence of T. gondii in these subjects was 7 %. Only the age of students showed a statistical association with T. gondii seropositivity. The level of awareness regarding toxoplasmosis was also investigated. In the sample, 71 % of the students are aware of toxoplasmosis and 64 % that a parasite is the cause of the infection. Most know it is transmitted through undercooked meat (57 %), but are unaware of contaminated vegetables (40 %), organ transplants (17 %), blood transfusions (32 %), and soil contact (39 %). In the epidemiological context it will be valuable to verify toxoplasmosis awareness in other population groups and other regions in Peru., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Toxoplasmosis affects about one-third of the world's population. The disease treatment methods pose several side effects and do not efficiently eliminate the parasite, making the search for new therapeutic approaches necessary. We aimed to assess the anti-Toxoplasma gondii activity of four Copaifera oleoresins (ORs) and two isolated diterpene acids, named ent-kaurenoic and ent-polyalthic acid. We used HeLa cells as an experimental model of toxoplasmosis. Uninfected and infected HeLa cells were submitted to the treatments, and the parasite intracellular proliferation, cytokine levels and ROS production were measured. Also, tachyzoites were pre-treated and the parasite invasion was determined. Finally, an in silico analysis was performed to identify potential parasite targets. Our data show that the non-cytotoxic concentrations of ORs and diterpene acids controlled the invasion and proliferation of T. gondii in HeLa cells, thus highlighting the possible direct action on parasites. In addition, some compounds tested controlled parasite proliferation in an irreversible manner. An additional and non-exclusive mechanism of action involves the modulation of host cell components, by affecting the upregulation of the IL-6. Additionally, molecular docking suggested that ent-polyalthic acid has a high affinity for the active site of the TgCDPK1 protein. Copaifera ORs have great antiparasitic activity against T. gondii, and this effect can be partially explained by the presence of the isolated compounds ent-kaurenoic and ent-polyalthic acid., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Inc.)

Toxoplasma gondii is an obligate intracellular parasite responsible for a pathology called toxoplasmosis, which primarily affects immunocompromised individuals and developing foetuses. The parasite can scavenge essential nutrients from its host to support its growth and survival. Among them, iron is one of the most important elements needed to sustain basic cellular functions as it is involved in a number of key metabolic processes, including oxygen transport, redox balance, and electron transport. We evaluated the effects of an iron chelator on the development of several parasite strains and found that they differed in their ability to tolerate iron depletion. The growth of parasites usually associated with a model of acute toxoplasmosis was strongly affected by iron depletion, whereas cystogenic strains were less sensitive as they were able to convert into persisting developmental forms that are associated with the chronic form of the disease. Ultrastructural and biochemical characterization of the impact of iron depletion on parasites also highlighted striking changes in both their metabolism and that of the host, with a marked accumulation of lipid droplets and perturbation of lipid homoeostasis. Overall, our study demonstrates that although acute iron depletion has an important effect on the growth of T. gondii , it has a more profound impact on actively dividing parasites, whereas less metabolically active parasite forms may be able to avoid some of the most detrimental consequences.

Toxoplasmosis, induced by the intracellular parasite Toxoplasma gondii , holds considerable implications for global health. While treatment options primarily focusing on folate pathway enzymes have notable limitations, current research endeavours concentrate on pinpointing specific metabolic pathways vital for parasite survival. Carbonic anhydrases (CAs, EC 4.2.1.1) have emerged as potential drug targets due to their role in fundamental reactions critical for various protozoan metabolic processes. Within T. gondii , the Carbonic Anhydrase-Related Protein (TgCA&#95;RP) plays a pivotal role in rhoptry biogenesis. Notably, α-CA (TcCA) from another protozoan, Trypanosoma cruzi , exhibited considerable susceptibility to classical CA inhibitors (CAIs) such as anions, sulphonamides, thiols, and hydroxamates. Here, the recombinant DNA technology was employed to synthesise and clone the identified gene in the T. gondii genome, which encodes an α-CA protein (Tg&#95;CA), with the purpose of heterologously overexpressing its corresponding protein. Tg&#95;CA kinetic constants were determined, and its inhibition patterns explored with inorganic metal-complexing compounds, which are relevant for rational compound design. The significance of this study lies in the potential development of innovative therapeutic strategies that disrupt the vital metabolic pathways crucial for T. gondii survival and virulence. This research may lead to the development of targeted treatments, offering new approaches to manage toxoplasmosis.

Repetitive elements in DNA sequences are a hallmark of Apicomplexan protozoa. A genome-wide screening for Tandem Repeats was conducted in Toxoplasma gondii and related Coccidian parasites with a novel strategy to assess compositional bias. A conserved pattern of GC skew and purine-pyrimidine bias was observed. Compositional bias was also present at the protein level. Glutamic acid was the most abundant amino acid in the purine (GA) rich cluster, while Serine prevailed in pyrimidine (CT) rich cluster. Purine rich repeats, and consequently glutamic acid abundance, correlated with high scores for intrinsically disordered protein regions/domains. Finally, variability was established for repetitive regions within a well-known rhoptry antigen (ROP1) and an uncharacterized hypothetical protein with similar features. The approach we present could be useful to identify potential antigens bearing repetitive elements., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Toxoplasma gondii is an obligate intracellular parasite that can infect a variety of mammals including humans and causes toxoplasmosis. Unfortunately, a protective and safe vaccine against toxoplasmosis hasn't been developed yet. In this study, we developed a DNA vaccine encoding the SRS13 protein and immunized BALB/c mice thrice with pVAX1-SRS13 through the intramuscular route (IM) or intradermally using an electroporation device (ID + EP). The immunogenicity of pVAX1-SRS13 was analyzed by ELISA, Western blot, cytokine ELISA, and flow cytometry. The protective efficacy of the pVAX1-SRS13 was investigated by challenging mice orally with T. gondii PRU strain tissue cysts. The results revealed that pVAX1-SRS13 administered through IM or ID + EP routes induced high level of anti-SRS13 IgG antibody responses (P = 0.0037 and P < 0.0001). The IFN-γ level elicited by the pVAX1-SRS13 (ID + EP) was significantly higher compared to the control group (P = 0.00159). In mice administered with pVAX1-SRS13 (ID + EP), CD8 + cells secreting IFN-γ was significantly higher compared to pVAX1-SRS13 (IM) (P = 0.0035) and the control group (P = 0.0068). Mice vaccinated with the SRS13 DNA vaccine did not induce significant IL-4 level. Moreover, a significant reduction in the number of tissue cysts and the load of T. gondii DNA was detected in brains of mice administered with pVAX1-SRS13 through ID + EP and IM routes compared to controls. In conclusion, the SRS13 DNA vaccine was found to be highly immunogenic and confers strong protection against chronic toxoplasmosis., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

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., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this article., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Background: Toxoplasmosis is caused by the protozoan parasite Toxoplasma gondii, a food- and water-borne zoonotic protozoan parasite that is able to infect almost all warm-blooded vertebrates. It has a major effect on public health, particularly in underdeveloped nations. Immune-competent individuals typically exhibit no symptoms or experience a mild influenza-like sickness, while there is a possibility of severe manifestation and fatal or high-risk for life-threatening diseases in immunocompromised people like pregnant women and HIV/AIDS patients and lead to severe pathological effects on the fetus., Method: We conducted a systematic search of databases (PubMed, Google Scholar, Science Direct, EMBASE, and Scopus) using the PRISMA criteria. We used specific keywords such as Toxoplasma gondii, Toxoplasmosis, pregnant women, prevalence, HIV/AIDS, and worldwide studies published from 2018 to 2022. We use Stata (version 14) software to estimate the pooled prevalence and heterogeneity of toxoplasmosis in pregnant women and HIV-infected people using a random-effects model and the Cochran's Q-test, respectively. The Joanna Briggs Institute Critical Appraisal Instrument and Egger's regression asymmetry test were used to assess study quality and publication bias, respectively, while the single study omission analysis was used to test the robustness of a pooled estimate., Results: We included and analyzed a total of 12,887 individuals in this review. The pooled prevalence of T. gondii in this review was 40% (95% CI = 0.31-0.50). The sub-group analysis revealed that the evaluation included 11,967 pregnant women. In pregnant women, the pooled sero-prevalence was 40% (95% CI = 0.31-0.50). In pregnant women and HIV/AIDS patients, 920 individuals were evaluated, and the pooled sero-prevalence was 41% (95% CI = 0.20-0.61)., Conclusion: This review identified an overall sero-prevalence of Toxoplasma infection of 40% among pregnant women and HIV/AIDS. The expansion of prevention and control strategies, with a primary focus on enhancing educational initiatives, is necessary to avoid reactivation and stop the spread of infection, so investigative sero-prevalence is important work among pregnant women and HIV patients. In order to achieve a comprehensive explanation of the disease condition and reach this goal, we conducted a systematic review and meta-analysis in Worldwide for future use., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

Previous studies have shown that bicyclic azetidines are potent and selective inhibitors of apicomplexan phenylalanine tRNA synthetase (PheRS), leading to parasite growth inhibition in vitro and in vivo, including in models of Toxoplasma infection. Despite these useful properties, additional optimization is required for the development of efficacious treatments of toxoplasmosis from this inhibitor series, in particular, to achieve optimal exposure in the brain. Here, we describe a series of PheRS inhibitors built on a new bicyclic pyrrolidine core scaffold designed to retain the exit-vector geometry of the isomeric bicyclic azetidine core scaffold while offering avenues to sample diverse chemical space. Relative to the parent series, bicyclic pyrrolidines retain reasonable potency and target selectivity for parasite PheRS vs host. Further structure-activity relationship studies revealed that the introduction of aliphatic groups improved potency and ADME and PK properties, including brain exposure. The identification of this new scaffold provides potential opportunities to extend the analogue series to further improve selectivity and potency and ultimately deliver a novel, efficacious treatment of toxoplasmosis.

Toxoplasma gondii is described as a potential cause of abortion in goats and as a threat to public health. To estimate the prevalence of goats infected by T. gondii, in different cities in the Espírito Santo State, and to identify possible risk factors for infection a serological study was conducted. A total of 146 goat serum samples from the cities of Cariacica, Serra and Vila Velha were analyzed. The presence of IgG Class Immunoglobulins was serologically evaluated by Immunofluorescence antibody test (IFAT) and by Enzyme-linked Immunosorbent Assay (ELISA). The seroprevalence of anti-T. gondii was 46.6% (68/146) in both techniques and the same samples got the same results in both techniques. Among the analyzed sera, 70.6% (48/68) exhibited high-avidity IgG antibodies, and 29.4% (20/68) exhibited low-avidity IgG antibodies, suggesting that the infection was chronic in the infected animals. Female sex, age group over two years old, water from the public supply system, storage of food and supplies in an open and unprotected place, and the presence of a domestic cat on the property were identified as risk factors for T. gondii infection in goats. The state of Espirito Santo has a high frequency of infected goats, and this is the first research on caprine toxoplasmosis seroepidemiology in that region., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier B.V.)

Purpose: Toxoplasmosis is caused by the parasite Toxoplasma gondii (T. gondii). In immunocompetent individuals, the infection is often asymptomatic; however, in expectant mothers and those with immune system deficiencies, complications may arise. Consequently, there is a need for new drugs that cause minimal damage to host cells. The purpose of this study was to investigate the in vitro antiparasitic efficacy of quinolone-coumarin hybrids QC1-QC12, derived from quinolone antibacterials and novobiocin, against T. gondii., Methods: The derivatives were compared with novobiocin and ciprofloxacin during testing, with pyrimethamine used as a positive control. We conducted the MTT assay to examine the anti-toxoplasmic effects of the test compounds and novobiocin. Evaluation included the infection and proliferation indices, as well as the size and number of plaques, based on the viability of both healthy and infected cells., Results: The in vitro assays revealed that QC1, QC3, QC6, and novobiocin, with selectivity indices (SIs) of 7.27, 13.43, and 8.23, respectively, had the least toxic effect on healthy cells and the highest effect on infected cells compared to pyrimethamine (SI = 3.05). Compared to pyrimethamine, QC1, QC3, QC6, and novobiocin Without having a significant effect on cell viability, demonstrated a significant effect on reducing in both infection index and proliferation index, in addition to reducing the quantity and dimensions of plaques ( P < 0.05)., Conclusion: Based on our results, QC1, QC3, QC6, and novobiocin due to their significant therapeutic effects could be considered as potential new leads in the development of novel anti-Toxoplasma agents., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

The present experimental survey designed to green synthesis, characterization, as well as in vitro and in vivo anti-Toxplasma gondii activity of silver nanoparticles (SLN) green synthesized by Lupinus arcticus extract. SLN were green synthesized based on the reducing by L. arcticus extract through the precipitation technique. In vitro lethal effects of SLN on T. gondii tachyzoites, infectivity rate, parasites inside of the human macrophage cells (THP-1 cells), nitric oxide (NO) triggering, and iNOS and interferon gamma (IFN-γ) expression genes were evaluated. In vivo, after establishment of toxoplasmosis in BALB/c mice via T. gondii ME49 strain, mice received SLN at 10 and 20 mg/kg/day alone and combined to pyrimethamine at 5 mg/kg for 14 days. SLN exhibited a spherical form with a size ranging from 25 to 90 nm. The 50% inhibitory concentration (IC 50 ) value of SLN and pyrimethamine against tachyzoites was 29.1 and 25.7 µg/mL, respectively. While, the 50% cytotoxic concentration (CC 50 ) value of SLN and pyrimethamine against THP-1 cells was 412.3 µg/mL and 269.5 µg/mL, respectively. SLN in combined with pyrimethamine obviously (p < 0.05) decreased the number and size of the T. gondii cysts in the infected mice. The level of NO, iNOS and IFN-γ genes was obviously (p < 0.001) upregulated. SLN obviously (p < 0.05) decreased the liver level of oxidative stress and increased the level of antioxidant factors. The findings displayed the promising beneficial effects of SLN mainly in combination with current synthetic drugs against latent T. gondii infection in mice. But we need more experiments to approve these findings, clarifying all possible mechanisms, and its efficiency in clinical phases., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Toxoplasmosis is a worldwide zoonosis that affects warm-blooded animals, including humans. Wild animals can act as intermediate hosts of this pathogen; thus, this study aims to detect Toxoplasma gondii infection in invasive European brown hares in Brazil. For this, 72 wild European brown hares were captured from July 2020 to June 2022 in three Brazilian states: São Paulo, Paraná, and Rio Grande do Sul. The diagnostic of Toxoplasma gondii infection was performed by bioassay in mouse, histopathology in Hematoxylin-Eosin-stained tissue sections (brain, liver, lungs, kidneys, and small intestine), serology by IFAT, and molecular techniques by conventional PCR and qPCR. The combined prevalence of the different diagnostic methods was 51.4% (37/72, CI= 40.1 - 62.6 %), and there was no statistical difference between sexes, age range, or geographical region of the hosts. Mouse bioassay was the technique that detected more positive hares. To our knowledge, this is the first confirmation of Toxoplasma gondii infection in invasive European brown hares in Brazil. These animals act as reservoirs and potential infection source for carnivores and other wild and domestic animals, including humans, thus contributing to perpetuate the disease cycle in São Paulo, Paraná, and Rio Grande do Sul States. Research such as the present study is necessary to raise awareness about the role of animals in the disease cycle., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Toxoplasmosis poses a global health threat, ranging from asymptomatic cases to severe, potentially fatal manifestations, especially in immunocompromised individuals and congenital transmission. Prior research suggests that oregano essential oil (OEO) exhibits diverse biological effects, including antiparasitic activity against Toxoplasma gondii. Given concerns about current treatments, exploring new compounds is important. This study was to assess the toxicity of OEO on BeWo cells and T. gondii tachyzoites, as well as to evaluate its effectiveness in in vitro infection models and determine its direct action on free tachyzoites. OEO toxicity on BeWo cells and T. gondii tachyzoites was assessed by MTT and trypan blue methods, determining cytotoxic concentration (CC 50 ), inhibitory concentration (IC 50 ), and selectivity index (SI). Infection and proliferation indices were analyzed. Direct assessments of the parasite included reactive oxygen species (ROS) levels, mitochondrial membrane potential, necrosis, and apoptosis, as well as electron microscopy. Oregano oil exhibited low cytotoxicity on BeWo cells (CC 50 : 114.8 µg/mL ± 0.01) and reduced parasite viability (IC 50 12.5 ± 0.06 µg/mL), demonstrating 9.18 times greater selectivity for parasites than BeWo cells. OEO treatment significantly decreased intracellular proliferation in infected cells by 84% after 24 h with 50 μg/mL. Mechanistic investigations revealed increased ROS levels, mitochondrial depolarization, and lipid droplet formation, linked to autophagy induction and plasma membrane permeabilization. These alterations, observed through electron microscopy, suggested a necrotic process confirmed by propidium iodide labeling. OEO treatment demonstrated anti-T. gondii action through cellular and metabolic change while maintaining low toxicity to trophoblastic cells., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

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., (© 2024. The Author(s).)

Ocular toxoplasmosis (OT) is an intraocular infection caused by the parasite Toxoplasma gondii. OT is manifested as retinal choroiditis and is the most common infectious cause of posterior uveitis. Invasion of the retina by T. gondii leads to disruption of the blood-ocular barrier and promotes the migration of immune cells to the ocular tissues. Cytokines such as IFN-γ and IL-1β are effective for controlling parasite growth, but excessive inflammatory responses can cause damage to the host. In this review, we will discuss in detail the latest advances in the immunopathology and treatment of OT., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Chen, Cheng, Chen, Zhang and Du.)

In a representative sample of female children and adolescents in Germany, Toxoplasma gondii seroprevalence was 6.3% (95% CI 4.7%-8.0%). With each year of life, the chance of being seropositive increased by 1.2, indicating a strong force of infection. Social status and municipality size were found to be associated with seropositivity.

This study presents an evaluation of seventeen newly produced recombinant trivalent chimeric proteins (containing the same immunodominant fragment of SAG1 and SAG2 of Toxoplasma gondii antigens, and an additional immunodominant fragment of one of the parasite antigens, such as AMA1, GRA1, GRA2, GRA5, GRA6, GRA7, GRA9, LDH2, MAG1, MIC1, MIC3, P35, and ROP1) as a potential alternative to the whole-cell tachyzoite lysate (TLA) used in the detection of infection in small ruminants. These recombinant proteins, obtained by genetic engineering and molecular biology methods, were tested for their reactivity with specific anti- Toxoplasma IgG antibodies contained in serum samples of small ruminants (192 samples of sheep serum and 95 samples of goat serum) using an enzyme-linked immunosorbent assay (ELISA). The reactivity of six recombinant trivalent chimeric proteins (SAG1-SAG2-GRA5, SAG1-SAG2-GRA9, SAG1-SAG2-MIC1, SAG1-SAG2-MIC3, SAG1-SAG2-P35, and SAG1-SAG2-ROP1) with IgG antibodies generated during T. gondii invasion was comparable to the sensitivity of TLA-based IgG ELISA (100%). The obtained results show a strong correlation with the results obtained for TLA. This suggests that these protein preparations may be a potential alternative to TLA used in commercial tests and could be used to develop a cheaper test for the detection of parasite infection in small ruminants.

Toxoplasma gondii is a pathogenic protozoan parasite of the Apicomplexa family that affects approximately 30% of the world's population. Symptoms are usually mild in immunocompetent hosts, but it can pose significant health risks to immunosuppressed patients and pregnant women. Current treatment options are limited, and new therapies and vaccines are needed. The innate immune system is the first to recognize T. gondii infection and activates pro-inflammatory cytokines and chemokines to promote acquired immunity. The IL-12/IFN-γ axis is particularly important, and when this pathway is inhibited, infection becomes uncontrolled and lethal. In mice, receptors such as Toll-like receptor 11 (TLR11), TLR12, and chemokine receptors are involved in T. gondii recognition and the modulation of immune responses. In humans, where TLR11 and TLR12 are absent, other mechanisms have been reported as the innate immune sensing system in T. gondii infection. Immune cells activated in response to infection produce interleukin (IL)-12, which stimulates the proliferation of natural killer cells and T cells and promotes the production of interferon (IFN)-γ. Several IFN-γ-induced anti-T. gondii defense mechanisms inhibit parasite growth. These include nitric oxide (NO) production, indoleamine 2,3-dioxygenase, and the destruction of parasitophorous vacuoles by IFN-γ-inducible immunity related GTPase groups (IRGs and GBPs). Recent studies focusing on the diversity of IRGs in rodents and effector molecules in T. gondii suggest that host immune mechanisms and pathogen immune evasion mechanisms have co-evolved. Furthermore, it has been suggested that cysts are not simply dormant during chronic infection. This review summarizes recent findings on anti-T. gondii innate, adaptive, and cell-autonomous immune responses., (© The Author(s) 2024. Published by Oxford University Press on behalf of The Japanese Society for Immunology.)

In an effort to identify novel compounds with potent inhibition against Toxoplasma gondii, a phenotypic screen was performed utilizing a library of 683 pure compounds derived primarily from terrestrial and marine fungi. An initial screen with a fixed concentration of 5 µM yielded 91 hits with inhibition comparable to an equal concentration of artemisinin. These compounds were then triaged based on known biological and chemical concerns and liabilities. From these, 49 prioritized compounds were tested in a dose response format with T. gondii and human foreskin fibroblasts (HFFs) for cytotoxicity. Ten compounds were identified with an IC 50 less than 150 nM and a selectivity index (SI) greater than 100. An additional eight compounds demonstrated submicromolar IC 50 and SI values equal to or greater than 35. While the majority of these scaffolds have been previously implicated against apicomplexan parasites, their activities in T. gondii were largely unknown. Herein, we report the T. gondii activity of these compounds with chemotypes including xanthoquinodins, peptaibols, heptelidic acid analogs, and fumagillin analogs, with multiple compounds demonstrating exceptional potency in T. gondii and limited toxicity to HFFs at the highest concentrations tested., Importance: Current therapeutics for treating toxoplasmosis remain insufficient, demonstrating high cytotoxicity, poor bioavailability, limited efficacy, and drug resistance. Additional research is needed to develop novel compounds with high efficacy and low cytotoxicity. The success of artemisinin and other natural products in treating malaria highlights the potential of natural products as anti-protozoan therapeutics. However, the exploration of natural products in T. gondii drug discovery has been less comprehensive, leaving untapped potential. By leveraging the resources available for the malaria drug discovery campaign, we conducted a phenotypic screen utilizing a set of natural products previously screened against Plasmodium falciparum . Our study revealed 18 compounds with high potency and low cytotoxicity in T. gondii , including four novel scaffolds with no previously reported activity in T. gondii . These new scaffolds may serve as starting points for the development of toxoplasmosis therapeutics but could also serve as tool compounds for target identification studies using chemogenomic approach., Competing Interests: The authors declare no conflict of interest.

Toxoplasma gondii is a pervasive protozoan parasite that is responsible for significant zoonoses. A wide array of vaccines using different effector molecules of T. gondii have been studied worldwide to control toxoplasmosis. None of the existing vaccines are sufficiently effective to confer protective immunity. Among the different Toxoplasma-derived effector molecules, T. gondii dense granule protein 15 from the type II strain (GRA15 (II)) was recently characterized as an immunomodulatory molecule that induced host immunity via NF-κB. Therefore, we assessed the immunostimulatory and protective efficacy of recombinant GRA15 (II) (rGRA15) against T. gondii infection in a C57BL/6 mouse model. We observed that rGRA15 treatment increased the production of IL-12p40 from mouse peritoneal macrophages in vitro. Immunization of mice with rGRA15 induced the production of anti-TgGRA15-specific IgG, IgG1 and IgG2c antibodies. The rGRA15-sensitized spleen cells from mice inoculated with the same antigen strongly promoted spleen cell proliferation and IFN-γ production. Immunization with rGRA15 significantly enhanced the survival rate of mice and dramatically decreased parasite burden in mice challenged with the Pru (type II) strain. These results suggested that rGRA15 triggered humoral and cellular immune responses to control infection. However, all of the immunized mice died when challenged with the GRA15-deficient Pru strain or the RH (type I) strain. These results suggest that GRA15 (II)-dependent immunity plays a crucial role in protection against challenge infection with the type II strain of T. gondii. This study is the first report to show GRA15 (II) as a recombinant vaccine antigen against Toxoplasma infection., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Pathogenic bacteria, viruses, fungi, and protozoa can cause food and waterborne diseases. Surveillance methods must therefore screen for these pathogens at various stages of water distribution and of food from production to consumption. Detection using nucleic acid amplification methods offer rapid identification, but such methods have limited utility for characterizing populations, variant types or virulence traits of pathogens. Whole genome sequencing (WGS) can be used to determine this information. However, pathogens must be isolated and cultured to yield sufficient DNA for WGS, which is laborious or not feasible for certain stages of parasites like oocysts of Toxoplasma gondii. We previously developed the Circular Nucleic acid Enrichment Reagent (CNER) method to make whole genome enrichment (WGE) baits for difficult-to-grow bacterial pathogens. WGE using CNERs facilitates direct sequencing of pathogens from samples without the need to isolate and grow them. Here, we made WGE-CNERs for T. gondii to demonstrate the use of the CNER method to make baits to enrich the large genomes of water and foodborne protozoan pathogens. By sequencing, we detected as few as 50 parasites spiked in an oyster hemolymph matrix. We discuss the use of WGE-CNERs for genomic surveillance of food and waterborne pathogens., Competing Interests: Declaration of competing interest B Sundararaman and RE Green are listed as co-inventors in a PCT application filed by the UCSC describing some of the methods presented here. B Sundararaman is founder and shareholder of GenZ Genomics Private Limited in Chennai, India., (Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Toxoplasmosis is a zoonosis that is a worldwide health problem, commonly affecting fetal development and immunodeficient patients. Treatment is carried out with a combination of pyrimethamine and sulfadiazine, which can cause cytopenia and intolerance and does not lead to a parasitological cure of the infection. Lysine deacetylases (KDACs), which remove an acetyl group from lysine residues in histone and non-histone proteins are found in the Toxoplasma gondii genome. Previous work showed the hydroxamate-type KDAC inhibitors Tubastatin A (TST) and Vorinostat (Suberoylanilide Hydroxamic Acid, SAHA) were effective against T. gondii. In the present study, the effects of three hydroxamates (KV-24, KV-30, KV-46), which were originally designed to inhibit human KDAC6, showed different effects against T. gondii. These compounds contain a heterocyclic cap group and a benzyl linker bearing the hydroxamic acid group in para-position. All compounds showed selective activity against T. gondii proliferation, inhibiting tachyzoite proliferation with IC 50 values in a nanomolar range after 48h treatment. Microscopy analyses showed that after treatment, tachyzoites presented mislocalization of the apicoplast, disorganization of the inner membrane complex, and arrest in the completion of new daughter cells. The number of dividing cells with incomplete endodyogeny increased significantly after treatment, indicating the compounds can interfere in the late steps of cell division. The results obtained in this work that these new hydroxamates should be considered for future in vivo tests and the development of new compounds for treating toxoplasmosis., Competing Interests: Declaration of competing interest The authors have none., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Toxoplasma gondii and Neospora caninum infections are important causes of abortion in ruminants. The objective of this study was to determine the seroprevalence and frequency of T. gondii and N. caninum titers in goats raised by family farmers in the Luracatao Valley of Salta province, Argentina. A total of 259 serum samples were collected from adult goats in 42 family farms in nine communities and tested for indirect fluorescent antibody test (IFAT, cut-off 1:100). Seroprevalences were 34.36% (89/259) for T. gondii and 64.09% (166/259) for N. caninum. Co-infection was found in 25.86% (67/259) of the goats tested. The most frequent IFAT titer of T. gondii found was 100 (23.93%; 62/259), and only 2% (5/259) of the goats presented titer 800. For N. caninum, the most frequent titers were 100 (25.86%; 67/259), and titers 200 (20.46%; 53/259) and 400 (14.61%, 38/259). The titers found for T. gondii could suggest a chronic infection in goats, being of importance for the region due to meat consumption and cheese production. The elevated seroprevalence of N. caninum identified in this study may be attributed to the community-specific dog population and the close interaction between dogs and goats, despite the absence of a statistically significant association. Subsequent research is warranted to assess the productive implications of T. gondii and N. caninum., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

Toxoplasma gondii is a single-celled parasite that causes a disease called toxoplasmosis. It can reach the central nervous system, but the mechanism of T. gondii disrupting the functioning of these brain regions occurs in bradyzoite stage of parasite, causing brain damage by forming tissue cysts in brain. In our study, the effects of T. gondii on locomotor activity, anxiety, learning and memory, and norepinephrine (NE), levodopa (L-DOPA), dopamine (DA) and 3,4-D-dihydroxyphenylacetic acid (DOPAC) catecholamines in amygdala, striatum, prefrontal cortex and hippocampus regions of the brain were investigated in bradyzoite stage. Twenty male Albino mice Mus musculus, 4-5 weeks old, weighing 20-25 g, were used. T. gondii inoculated to mice intraperitonealy with 48-50-hour passages of T. gondii RH Ankara strain. For intraperitoneal inoculation of mice 5x10 4 tachyzoites per mouse. No inoculation was made in control group (n: 20). Locomotor activity behavior in open field test (OFT), anxious behavior in elevated plus maze (EPM), and learning behavior in novel object recognition (NOR) tests were evaluated. NE, L-DOPA, DA and DOPAC were measured by HPLC in brain tissues of amygdala, striatum, prefrontal cortex and hippocampus. A decrease was observed in the locomotor activity, anxiety and learning values of the T. gondii group compared to the control group (p < 0.05). The heighten in NE and L-DOPA levels in amygdala tissue of T. gondii group compared to control group, an elevation in NE, L-DOPA, DA and DOPAC levels in striatum tissue, and an increase in levels of NE in prefrontal cortex tissue were detected in monoamine results. In hippocampus tissue, an increase was observed in DA levels, while a decrease was observed in NE, L-DOPA and DOPAC levels. In our study, it has been shown that T. gondii in bradyzoite stage reduces locomotor activity, causes learning and memory impairment, and has anxiogenic effects., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Toxoplasma gondii is a widespread and specialized intracellular protozoan pathogen that affects one third of the world' s population, posing a great threat to public health. As the definitive host, cats excrete oocysts and play a crucial role in the transmission of toxoplasmosis. The current diagnostic tools usually require bulky equipment and expertize, which hinders the efficient diagnosis and intervention of Toxoplasma infection in cats. In this study, we combined (RPA) with clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 technique to establish an easier method for the detection of T. gondii oocysts in cat fecal samples. The sensitivity, specificity, and practicability of the established RPA-CRISPR/Cas9 method were evaluated using a lateral flow strip, with the limitation of detection determined at 10 plasmid copies/μL (corresponding to about one oocyst), cross reactivity to none of Giardia lamblia, Cryptosporidium sp., Microsporidium biberi and Blastocystis hominis that also commonly found in cats, and comparable performance in detecting T. gondii in clinical samples to conventional PCR amplification. This RPA-CRISPR/Cas9 method provides an alternative to conventional molecular tools used in the clinical diagnosis of Toxoplasma infection in cats and other animals., Competing Interests: Declaration of Competing Interest The authors declare that they have no competing interests., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Toxoplasmosis is a zoonosis caused by Toxoplasma gondii (T. gondii). The current treatment for toxoplasmosis remains constrained due to the absence of pharmaceutical interventions. Thus, the pursuit of more efficient targets is of great importance. Lipid metabolism in T. gondii, including fatty acid metabolism, phospholipid metabolism, and neutral lipid metabolism, assumes a crucial function in T. gondii because those pathways are largely involved in the formation of the membranous structure and cellular processes such as division, invasion, egress, replication, and apoptosis. The inhibitors of T. gondii's lipid metabolism can directly lead to the disturbance of various lipid component levels and serious destruction of membrane structure, ultimately leading to the death of the parasites. In this review, the specific lipid metabolism pathways, correlative enzymes, and inhibitors of lipid metabolism of T. gondii are elaborated in detail to generate novel ideas for the development of anti-T. gondii drugs that target the parasites' lipid metabolism., (© 2024. The Author(s).)

Toxoplasma gondii (TOXO) infection typically results in chronic latency due to its ability to form cysts in the brain and other organs. Latent toxoplasmosis could promote innate immune responses and impact brain function. A large body of evidence has linked TOXO infection to severe mental illness (SMI). We hypothesized that TOXO immunoglobulin G (IgG) seropositivity, reflecting previous infection and current latency, is associated with increased circulating neuron-specific enolase (NSE), a marker of brain damage, and interleukin-18 (IL-18), an innate immune marker, mainly in SMI. We included 735 patients with SMI (schizophrenia or bipolar spectrum) (mean age 32 years, 47% women), and 518 healthy controls (HC) (mean age 33 years, 43% women). TOXO IgG, expressed as seropositivity/seronegativity, NSE and IL-18 were measured with immunoassays. We searched for main and interaction effects of TOXO, patient/control status and sex on NSE and IL-18. In the whole sample as well as among patients and HC separately, IL-18 and NSE concentrations were positively correlated (p < 0.001). TOXO seropositive participants had significantly higher NSE (3713 vs. 2200 pg/ml, p < 0.001) and IL-18 levels (1068 vs. 674 pg/ml, p < 0.001) than seronegative participants, and evaluation within patients and HC separately showed similar results. Post-hoc analysis on cytomegalovirus and herpes simplex virus 1 IgG status showed no associations with NSE or IL-18 which may suggest TOXO specificity. These results may indicate ongoing inflammasome activation and neuronal injury in people with TOXO infections unrelated to diagnosis., (© 2024. The Author(s).)

Toxoplasmosis is a zoonotic disease with a worldwide prevalence that is caused by Toxoplasma gondii. This study aimed to summarize available data on genotyping T. gondii strains based on the GRA6 gene marker in different hosts around the world. We conducted a comprehensive literature search using five international databases (PubMed, Scopus, Science Direct, Web of Science, and Google Scholar) from inception until December 2021. We identified 32 papers eligible for inclusion in this systematic review. The majority of studies (50%) were carried out in Iran (n = 16) to identify T. gondii genotypes based on the GRA6 gene. Other countries with reported studies include China, Japan, Sweden, and Italy (n = 2 each). Out of 3,434 samples collected from various hosts, most studies (n = 11) focused on human samples (34.4%), followed by ovine (n = 7), pig (n = 4), goat (n = 3) and soil and cattle (n = 2).Using various molecular methods such as conventional PCR, nested-PCR, real-time PCR, microsatellite analysis, and Restriction Fragment Length Polymorphism (RFLP), we found DNA positive results in 805 out of 3,434 samples. Of these, 285 (35.40%), 207 (25.71%), 182 (22.60%), 65 (8.07%), and 18 (2.23%) were infected with types I, II, III, mix I, II, III, and mix II, III, respectively. Our data demonstrate that the GRA6 gene marker has sufficient polymorphism to detect three types of T. gondii genotypes in various hosts. Identifying the specific genotype could be valuable in developing new strategies for treatment, vaccination, diagnosis, control, and prevention of T. gondii infection., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Background: Persistent inflammation related to aging ("inflammaging") is exacerbated by chronic infections and contributes to frailty in older adults. We hypothesized associations between Toxoplasma gondii (T. gondii), a common parasite causing an oligosymptomatic unremitting infection, and frailty, and secondarily between T. gondii and previously reported markers of immune activation in frailty., Methods: We analyzed available demographic, social, and clinical data in Spanish and Portuguese older adults [N = 601; age: mean (SD) 77.3 (8.0); 61% women]. Plasma T. gondii immunoglobulin G (IgG) serointensity was measured with an enzyme-linked immunosorbent assay. The Fried criteria were used to define frailty status. Validated translations of Mini-Mental State Examination, Geriatric Depression Scale, and the Charlson Comorbidity Index were used to evaluate confounders. Previously analyzed biomarkers that were significantly associated with frailty in both prior reports and the current study, and also related to T. gondii serointensity, were further accounted for in multivariable logistic models with frailty as outcome., Results: In T. gondii-seropositives, there was a significant positive association between T. gondii IgG serointensity and frailty, accounting for age (p = .0002), and resisting adjustment for multiple successive confounders. Among biomarkers linked with frailty, kynurenine/tryptophan and soluble tumor necrosis factor receptor II were positively associated with T. gondii serointensity in seropositives (p < .05). Associations with other biomarkers were not significant., Conclusions: This first reported association between T. gondii and frailty is limited by a cross-sectional design and warrants replication. While certain biomarkers of inflammaging were associated with both T. gondii IgG serointensity and frailty, they did not fully mediate the T. gondii-frailty association., (© The Author(s) 2023. Published by Oxford University Press on behalf of The Gerontological Society of America.)

Background: The wild boar (Sus scrofa) and the Apennine wolf (Canis lupus italicus) are two wild species that have both increased their presence in the Italian territory, albeit in varying numbers. They can be occasionally found in peri-urban areas as well. Both of these species can serve as intermediate hosts for Toxoplasma gondii, as they can become infected either through the consumption of oocysts found in water, soil, or on vegetables, or through the ingestion of meat containing bradyzoites. Consequently, these animals can be regarded as key indicators of Toxoplasma presence in the wild or peri-urban environment. In our study, we examined a total of 174 wild boar meat juice and 128 wolf sera from Italy for the detection of T. gondii IgG using the indirect fluorescent antibody test (IFAT)., Results: The results showed that 40 (22.6%) of the wild boar meat juice and 34 (26.6%) of the wolf serum samples tested positive. Interestingly, there were no significant differences in seropositivity with respect to gender, age group, or the region of origin in both species., Conclusions: Overall the results indicate a moderate exposure in both the species under investigation, highlighting the spread of T. gondii in sylvatic and periurban environments. The prevalence of T. gondii in wild boar is consistent with findings from other studies conducted in Europe. Our study, with a considerably larger sample size compared to the available research in European context, provides valuable data on the seroprevalence of T. gondii in wolves., (© 2024. The Author(s).)

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., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Congenital toxoplasmosis in humans and in other mammalian species, such as small ruminants, is a well-known cause of abortion and fetal malformations. The calcium-dependent protein kinase 1 (CDPK1) inhibitor BKI-1748 has shown a promising safety profile for its use in humans and a good efficacy against Toxoplasma gondii infection in vitro and in mouse models. Ten doses of BKI-1748 given every other day orally in sheep at 15 mg/kg did not show systemic or pregnancy-related toxicity. In sheep experimentally infected at 90 days of pregnancy with 1000 TgShSp1 oocysts, the BKI-1748 treatment administered from 48 hours after infection led to complete protection against abortion and congenital infection. In addition, compared to infected/untreated sheep, treated sheep showed a drastically lower rectal temperature increase and none showed IgG seroconversion throughout the study. In conclusion, BKI-1748 treatment in pregnant sheep starting at 48 hours after infection was fully effective against congenital toxoplasmosis., Competing Interests: Potential conflicts of interest . W. C. V. V. is the President and co-owner of ParaTheraTech Inc, a company that is developing BKIs for animal health. He did not perform the experiments, nor interpret the results of the experiments, but did edit this article and helped plan the experiments. All other authors report no potential conflicts. All authors have submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Conflicts that the editors consider relevant to the content of the manuscript have been disclosed., (© The Author(s) 2023. Published by Oxford University Press on behalf of Infectious Diseases Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

This study aimed to determine the nPCR-RFLP genotypes of newly obtained T. gondii isolates from human congenital toxoplasmosis cases in Argentina and to determine their allelic profiles for virulence genes ROP18/ROP5. In addition, the ROP18/ROP5 profiles were also determined for previously characterized T. gondii samples. Isolation from congenital toxoplasmosis cases was carried out in mouse bioassay from two placentas (P1 and P2). Genotyping for the new human isolates was performed by nPCR-RFLP using 10 markers. The samples analyzed for ROP18/ROP5 included the two newly obtained isolates (from the congenital toxoplasmosis cases) and nine previously genotyped T. gondii DNA samples from humans and chickens. The results for P1 and P2 named as TgHm18-02Arg and TgHm19-01Arg showed ToxoDB genotypes #14 (non-archetypal) and #2 (clonal type III), respectively. Non-archetypal #14 has been isolated from human cases before in Argentina. However, this is the first report of T. gondii clonal type III in a human case in the country. The ROP18/ROP5 combination was detected in nine samples: 3/3 (n = 1), 4/3 (n = 4), 4/4 (n = 3), and 3-4/4 (n = 1). Notably, the 4/4 profile was identified for the first time and exclusively in T. gondii samples from Misiones province (which borders southern Brazil). Further studies are required to corroborate the regionalization of the ROP18/ROP5 profiles in Argentina., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Interferons (IFNs) are a family of cytokines with diverse functions in host resistance to pathogens and in immune regulation. Type II IFN, i.e. IFN-γ, is widely recognized as a major mediator of resistance to intracellular pathogens, including the protozoan Toxoplasma gondii . More recently, IFN-α/β, i.e. type I IFNs, and IFN-λ (type III IFN) have been identified to also play important roles during T. gondii infections. This parasite is a widespread pathogen of humans and animals, and it is a model organism to study cell-mediated immune responses to intracellular infection. Its success depends, among other factors, on the ability to counteract the IFN system, both at the level of IFN-mediated gene expression and at the level of IFN-regulated effector molecules. Here, I review recent advances in our understanding of the molecular mechanisms underlying IFN-mediated host resistance and immune regulation during T. gondii infections. I also discuss those mechanisms that T. gondii has evolved to efficiently evade IFN-mediated immunity. Knowledge of these fascinating host-parasite interactions and their underlying signalling machineries is crucial for a deeper understanding of the pathogenesis of toxoplasmosis, and it might also identify potential targets of parasite-directed or host-directed supportive therapies to combat the parasite more effectively., Competing Interests: The author declares that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Lüder.)

Auranofin, an FDA-approved drug for rheumatoid arthritis, has emerged as a promising antiparasitic medication in recent years. The gold(I) ion in auranofin is postulated to be responsible for its antiparasitic activity. Notably , aurothiomalate and aurothioglucose also contain gold(I), and, like auranofin, they were previously used to treat rheumatoid arthritis. Whether they have antiparasitic activity remains to be elucidated. Herein, we demonstrated that auranofin and similar derivatives, but not aurothiomalate and aurothioglucose, inhibited the growth of Toxoplasma gondii in vitro . We found that auranofin affected the T. gondii biological cycle (lytic cycle) by inhibiting T. gondii's invasion and triggering its egress from the host cell. However, auranofin could not prevent parasite replication once T. gondii resided within the host. Auranofin treatment induced apoptosis in T. gondii parasites , as demonstrated by its reduced size and elevated phosphatidylserine externalization (PS). Notably, the gold from auranofin enters the cytoplasm of T. gondii, as demonstrated by scanning transmission electron microscopy-energy dispersive X-ray spectroscopy (STEM-EDS) and Inductively Coupled Plasma-Mass Spectrometry (ICP-MS).IMPORTANCEToxoplasmosis, caused by Toxoplasma gondii , is a devastating disease affecting the brain and the eyes, frequently affecting immunocompromised individuals. Approximately 60 million people in the United States are already infected with T. gondii , representing a population at-risk of developing toxoplasmosis. Recent advances in treating cancer, autoimmune diseases, and organ transplants have contributed to this at-risk population's exponential growth. Paradoxically, treatments for toxoplasmosis have remained the same for more than 60 years, relying on medications well-known for their bone marrow toxicity and allergic reactions. Discovering new therapies is a priority, and repurposing FDA-approved drugs is an alternative approach to speed up drug discovery. Herein, we report the effect of auranofin, an FDA-approved drug, on the biological cycle of T. gondii and how both the phosphine ligand and the gold molecule determine the anti-parasitic activity of auranofin and other gold compounds. Our studies would contribute to the pipeline of candidate anti- T. gondii agents., Competing Interests: The authors declare no conflict of interest.