Toxoplasma gondii is a cosmopolitan protozoon parasite, and the causative agent of toxoplasmosis, one of the most prevalent zoonotic parasitic diseases. Cats, as definitive hosts, are spreaders of the parasite via their faeces, but this occurs only for a very short period in their life. Seropositivity in cats, although not associated with current shedding of the parasite, is indicative of the infection in a cat population and can be used to assess the infection risk for definitive and intermediate hosts in that area. In order to assess the prevalence of infection in cats living in Cyprus, 155 cats, originating from all districts of the country, were examined for the presence of T. gondii antibodies. Additionally, parameters such as age, sex, health status, lifestyle and concomitant infections were statistically assessed as potential risk factors for T. gondii seropositivity. Specific anti-T. gondii antibodies were detected in 50 (32.3%) cats, while the presence of feline immunodeficiency virus antibodies and a history of never having been vaccinated were statistically associated with T. gondii seropositivity on multivariate logistic regression model. This is the first report of T. gondii seroprevalence in cats in Cyprus and indicates that raised public awareness should be considered to prevent infection of animals and humans.

Background: The liver has emerged as a frequent transplanted organ which can transmit T. gondii between seropositive donors and seronegative recipients. Associated with the immunosuppressive therapy of recipients, the presence of cysts in donor livers elevate the risk of severe toxoplasmosis in recipients. Objectives: The objective of the study was to verify the frequencies of positive serology in liver graft donors and their respective recipients, as well as to verify whether their clinical signs presented post-transplant are associated with the serological status of recipients. Patients and methods: All data on liver transplant recipients from 2008 to 2018 were obtained from the MVPeP electronic medical records of the Liver Transplant Service of FUNFARME/FAMERP. IgM and IgG anti-T. gondii antibody serology was investigated by chemiluminescence. According to the serological profile, four groups of recipients were assessed (G1: IgG-/IgM-; G2: IgG+/IgM-; G3: IgG+/IgM+, G4: IgG-/IgM+). Results: The numbers of recipients according to the serological profile groups were: G1: 20 (41.7%), G2: 26 (54.1%; G3: 2 (4.2%). No cases were found for G4. Post-transplant clinical manifestations such as fever without defined cause, lung nodules, headache, hepatosplenomegaly, encephalopathy and hepatitis (A, B and C) were reported in all groups. Conclusions: This study demonstrates that there is a high prevalence of T. gondii infection in liver recipients and, therefore, screening should be intensified. Furthermore, a high incidence of co-infection with hepatitis A was identified especially in patients who died in the post-transplant period.

Toxoplasma gondii (T. gondii) is one of the most common parasites that infect humans. The parasite exists in approximately 40 million people in the United States. Latent infections are frequently associated with tissue cysts of T. gondii in the skeletal muscle and brain tissue that can lead to mental disorders, congenital disorders, and vision dysfunction. Furthermore, self-directed violence, impulsivity, and aggression are associated with T. gondii infection. Dopamine is associated with human behavior including pleasure, aggression, memory, and substance use disorder; however, the result of the studies on the association of T. gondii infection and drugs of abuse are not well understood. The frequency of substance use may be associated with substance-induced modification of dopamine-receptor densities and basal dopaminergic activity. Likewise, T. gondii can directly or indirectly influence dopaminergic activity in infected cells. Based on this hypothesis, the current paper aimed to systematically review all published literature on the association between drugs of abuse and T. gondii infection. Systematic review of controlled studies on T. gondii infection and substance use effects in adults were searched on the electronic databases. Studies have shown that individuals infected with T. gondii display increased risky behavior, such as excessive alcohol consumption. Furthermore, it was observed that T. gondii seropositive subjects had a reduced likelihood of self-reported substance use compared to T. gondii seronegative subjects. This study confirms that SUD is a potential risk factor for behavioral and psychiatric complications associated with T. gondii infection. Ultimately T. gondii infection in the context of drug dependence and the development of SUD remain to be elucidated. Therefore, it is necessary to conduct further research characterizing the mechanisms associated with dopamine metabolism of drug dependence and withdrawal in the context of a T. gondii infection, evaluating the role of inflammation, and identifying potential drug-and-sex specific underpinnings of these associations.

Objective: To evaluate which risk factors contribute directly or indirectly to Toxoplasma gondii infection in patients with ocular toxoplasmosis. Methods: Between 2018-2020, a total of 306 patients were selected, and treated at the Retinology Outpatient Clinic of the Specialty Hospital of Sāo José do Rio Preto, in the state of São Paulo. After the fundoscopy test, the Enzyme Linked Fluorescent Assay (ELFA) was used to determine IgG and IgM class anti-Toxoplasma gondii antibodies. Results: The results showed that individuals aged 60 years or older, and women who had a previous pregnancy, (p=0.000, OR= 8.137 and 95 % CI = 2.562 – 25.844), (p=0.016, OR= 7.395 and CI 95 % = 1,449 – 37,725) respectively, were 48.6 % more likely to develop ocular toxoplasmosis. Conclusion: In this way, previous pregnancy is a risk factor for the reactivation of toxoplasma, as well as for the generation of retinochoroiditis in previously infected women.

Toxoplasma gondii is a widespread protozoan parasite that infects most warm-blooded animals, and felids can serve as intermediate and definitive hosts. Pathological diagnosis and serological and etiological investigations were conducted on a captive caracal (Caracal caracal) carcass collected from China in 2022. Pathological diagnosis revealed that cardiac insufficiency, pulmonary edema, hepatic failure, and renal insufficiency were the causes of the caracal’s death. A modified agglutination test (cut-off: 1:25) revealed that IgG antibodies against T. gondii were present in the myocardium juice, hydroperitoneum, and hydropericardium (≥1:800). A viable T. gondii (TgCaracalCHn2) strain was isolated from the tissue samples (heart, brain, spleen, and skeletal muscle) of this caracal using a mouse bioassay. The genotype of TgCaracalCHn2 was ToxoDB#5 (Type II variant), as determined by RFLP-PCR. The strain was avirulent in Swiss mice and matched the prediction of ROP18 and ROP5 gene alleles of TgCaracalCHn2 (2/2). Many tissue cysts (203 ± 265) were observed in mice brains after inoculation with TgCaracalCHn2 tachyzoites. ToxoDB#5 is the dominant genotype in North American wildlife, and this is the first documented isolation of T. gondii ToxoDB#5 from China. This indicates that caracals can accelerate the transmission of T. gondii genotypes.

Myocastor coypus is a pest animal present in Africa, Europe, North America, and Asia that causes agricultural and ecological damages. Moreover, it has to be considered as a potential risk for public health. Forty-four Nutrias from the “Parco Naturale La Mandria” (Piedmont region, Northwest Italy) have been analysed. A complete necropsy and a whole histological evaluation of liver, kidney and lung have been carried out on all the animals. Moreover, the positivity to Hepatitis E Virus (HEV), Encephalomyocarditis virus (EMCV), Francisella spp., Toxoplasma gondii and Neospora caninum have been investigated. None of the animal resulted positive for HEV, EMCV, Francisella spp. or Neospora caninum. Two animals tested positive for Toxoplasma gondii. A high presence of histological lesions has been identified in different organs, suggesting that lesions could be induced by different pathogens. As previously reported, Nutria can act as a host for several pathogens, including important agents for human and animal health, and surveillance is necessary, to fully understand the biological role and the importance of coypu as a disease reservoir in our country.

Toxoplasmosis is a neglected anthropozoonosis caused by the obligate intracellular protozoan, Toxoplasma gondii. The role of non-human primates in the epidemiology of human toxoplasmosis is not clear. Acute and highly fatal cases of toxoplasmosis are frequently reported in new world monkeys and asymptomatic infections in old world monkeys. Here we report detection of latent natural T. gondii infection in olive baboons during a screening exercise to select animals for an experimental toxoplasmosis study. Archived serum samples from 32 olive baboons (Papio anubis), 23 wild caught and nine colony-born, were screened for T. gondii DNA using nested PCR. Eighteen (56.25%) samples were from females and fourteen (43.75%) from males. Toxoplasma gondii DNA was detected in 21 (65.6%) baboons. 13 females (40. 6%) and eight males (25%). Five baboons (24%) which tested positive were from the Institute of Primate Research colony but there was no statistical significance between them and the wild trapped (p=0.453). There was neither statistical significance (p=0.373) between sex and infection status nor between area of origin and infection status (p>0.05). These results indicate that olive baboons get infected with T. gondii in the wild and during captivity and may be significant reservoirs of human infections, especially where they may be trapped for bushmeat. We recommend a country-wide study to establish true prevalence of toxoplasmosis among non-human primates and identify associated parasite strains.

Toxoplasma gondii, a protozoan parasite with the ability to infect various warm-blooded vertebrates, including humans, is the causative agent of toxoplasmosis. This infection poses significant risks, leading to severe complications in immunocompromised individuals and potentially affecting the fetus through congenital transmission. A comprehensive understanding of the intricate molecular interactions between T. gondii and its host is pivotal for the development of effective therapeutic strategies. This review emphasizes the crucial role of proteomics in T. gondii research, with a specific focus on host-parasite interactions, post-translational modifications (PTMs), PTM crosstalk, and ongoing efforts in drug discovery. Additionally, we provide an overview of recent advancements in proteomics techniques, encompassing interactome sample preparation methods such as BioID, APEX, and Y2H, as well as various proteomics approaches, including single-cell analysis, DIA, targeted, top-down, and plasma proteomics. Furthermore, we discuss the integration of proteomics with other omics technologies, highlighting its potential in unraveling the intricate mechanisms of T. gondii pathogenesis and identifying novel therapeutic targets.

Despite the available literature on traumatic brain injury (TBI) biomarkers elsewhere, data are limited or non-existent in sub-Saharan Africa (SSA). The aim of the study was to analyse associations in acute TBI between admission serum biomarker concentrations and TBI severity, CT-scan findings and outcome as well as explore the influence of concurrent Toxoplasma gondii infection. Concentrations of serum biomarkers (GFAP, NFL Tau, UCH-L1, and S100B) were measured and Toxoplasma gondii detected in samples obtained <24 hours post-injury. The GOSE was used to evaluate 6 months outcome. All biomarkers levels increased with severity of TBI, but this increase was significant only for NFL (P=0.01). GFAP values significantly increased (P=0.026) in those with unfavorable outcome. Tau levels were higher in those who died (P=0.017). GFAP and NFL were sensitive to CT-scan pathology (p values respectively 0.004 and 0.002). S100B levels were higher (P<0.001) in TBI patients seropositive to Toxoplasma gondii. NFL was found to be sensitive to TBI severity while NFL and GFAP were predictive of CT intracranial abnormalities. Increased levels of GFAP and Tau were associated with poorer outcomes 6 months after TBI. S100B levels were significantly higher in T. gondii seropositive TBI patients.

The quinolone decoquinate (DCQ) is widely used in veterinary practice for the treatment of bacte-rial and parasitic infections, most notably coccidiosis in poultry and in ruminants. We have in-vestigated the effects of treatment of Toxoplasma gondii in infected human foreskin fibroblasts (HFF) with DCQ. It induced distinct alterations in the parasite mitochondrion within 24h, which persisted even after long-term (500 nM, 52 days) treatment, although there was no parasiticidal effect. Based on the low half-maximal effective concentration (IC50) of 1.1 nM and the high selec-tivity index of >5000, the efficacy of oral treatment of pregnant mice experimentally infected with T. gondii oocysts with DCQ at 10 mg/kg/day for 5 days was assessed. However, the treatment had detrimental effects, induced higher neonatal mortality than T. gondii infection alone, and did not prevent vertical transmission. Thus, three quinoline-O-carbamate derivatives of DCQ antici-pated to have better physicochemical properties than DCQ were assessed in vitro. One such com-pound RMB060 displayed an exceedingly low IC50 of 0.07 nM when applied concomitantly with infection of host cells and had no impact on HFF viability at 10 µM. As was the case for DCQ, RMB060 treatment resulted in alteration of the mitochondrial matrix and loss of cristae, but the changes became apparent at just 6h after commencement of treatment. After 48h, RMB060 induced the expression of the bradyzoite antigen BAG1, but TEM did not reveal any other features remi-niscent of bradyzoites. Exposure of infected cultures to 300 nM RMB060 for 52 days did not re-sult in complete killing of all tachyzoites, although mitochondria remained ultrastructurally damaged and there was a slower proliferation rate. Treatment of mice infected with T. gondii oocysts with RMB060 did reduce parasite burden in non-pregnant mice and dams, but vertical transmission to pups could not be prevented.

Toxoplasmosis is a zoonotic disease caused by the apicomplexa protozoan parasite Toxoplasma gondii. This disease is a health burden, mainly in pregnant women and immunocompromised individuals. Dehydroepiandrosterone (DHEA) has proved to be an important molecule that could drive resistance against a variety of infections, including intracellular parasites such as Plasmodium falciparum and Trypanozoma cruzi, among others. However, to date it has not been explored the role of DHEA on T. gondii. In here, we demonstrated for the first time the toxoplasmicidal effect of DHEA on extracellular tachyzoites. Ultrastructural analysis of treated parasites showed that DHEA alters the cytoskeleton structures, leading to the loss of the organelle structure and organization, as well as the loss of the cellular shape. In vitro treatment with DHEA reduces the viability of extracellular tachyzoites and passive invasion process. 2D SDS-PAGE analysis revealed that in the presence of the hormone a progesterone receptor membrane component (PGRMC) with a cytochrome b5 family heme/steroid binding domain-containing protein was expressed, while the expression of proteins that are essential for motility and virulence was highly reduced. Finally, in vivo DHEA treatment induced a reduction of parasitic load in male, but not in female mice.

Although the parasite Toxoplasma gondii is one of the most pervasive neurotropic pathogens in the world, the host-parasite interactions during CNS infection and consequences of neurological infection are just beginning to be unraveled. The chronic stages of infection have been considered dormant, although several studies have found correlations of infection with an array of host behavioral changes. These may facilitate parasite transmission and impact neurological diseases. During infection, in addition to the presence of the parasites within neurons, host-mediated neuroimmune and hormonal responses to infection are also present. T. gondii induces numerous changes to host neurons during infection and globally alters host neurological signaling pathways, as discussed in this review. Understanding the neurophysiological changes in the host brain is imperative to understanding the parasitic mechanisms and to delineate the effects of this single-celled parasite on health and its contribution to neurological disease.

Microtubule organizing centers (MTOCs) perform critical cellular tasks by nucleating, stabilizing and anchoring microtubule’s minus ends. These capacities impact tremendously a wide array of cellular functions ranging from ascribing cell shape to orchestrating cell division and generating motile structures, among others. The phylum Apicomplexa comprises over 6000 single-celled obligate intracellular parasitic species. Many of the apicomplexan are well known pathogens such as Toxoplasma gondii and the Plasmodium species, causative agents of toxoplasmosis and malaria, respectively. Microtubule organization in these parasites is critical for organizing the cortical cytoskeleton, enabling host cell penetration and the positioning of large organelles, drive cell division and direct the formation of flagella in sexual life stages. Apicomplexans are a prime example of MTOC diversity displaying multiple functional and structural MTOCs combinations within a single species. This diversity can only be fully understood in light of each organism's specific MT nucleation requirements and their evolutionary history. Insight into apicomplexan MTOCs had traditionally been limited to classical ultrastructural work by transmission electron microscopy. However, in the past few years, a large body of molecular insight has emerged. In this work we describe the latest insights into nuclear MTOC biology in two major human and animal disease causing Apicomplexans; Toxoplasma gondii and Plasmodium spp.

The success of Toxoplasma gondii (intracellular parasite) host cell invasion relies on the apical complex, a specialized microtubule cytoskeleton structure associated with secretory organelles. The genome encodes three isoforms of both α- and β-tubulin which are altered by specific post-translational modifications (PTMs), changing the biochemical/biophysical proprieties of microtubules, and modulating their interaction with associated proteins. Tubulin PTMs are a powerful and evolutionarily conserved mechanism to generate tubulin diversity, forming a biochemical ‘tubulin code’ that can be ‘read’ by microtubule-interacting factors. The T. gondii tubulin PTMs are: α-tubulin acetylation, α-tubulin detyrosination, Δ5α-tubulin, Δ2α-tubulin, α- and β-tubulin polyglutamylation, and α- and α-tubulin methylation. Tubulin glutamylation is a key candidate to assist microtubule remodeling in Toxoplasma, being involved in the regulation of microtubule stability, dynamics, interaction with motor proteins, and severing enzymes. The correct balance of tubulin glutamylation is achieved by the coordinated action of polyglutamylases and deglutamylating enzymes. In this work we will review and discuss the current knowledge on T. gondii tubulin glutamylation. By in silico identification of mammalian protein orthologs we explored and updated the identification of putative proteins related to glutamylation, contributing to a better understanding of the role of tubulin glutamylation in T. gondii.

Our study investigated the innate immune response to Toxoplasma gondii infection by assessing microglial phenotypic changes and sickness behavior as inflammatory response markers post-ocular tachyzoite instillation. Disease progression in Swiss albino mice was compared with documented outcomes in BALB/c mice using identical ocular route and parasite burden (2x105 tachyzoites), with saline as control. Contrary to expectations, Swiss albino mice displayed rapid, lethal disease progression, marked by pronounced sickness behaviors and mortality within 11-12 days post-infection, while survivors showed no apparent signs of infection. Comparative analysis revealed T. gondii-infected BALB/c mice exhibited reduced avoidance of feline odors, while in-fected Swiss albino mice showed enhanced avoidance responses. There was a significant increase in microglial cells in the dentate gyrus molecular layer of infected Swiss albino mice compared to BALB/c mice and their respective controls. Hierarchical cluster and discriminant analyses iden-tified three microglial morphological clusters, differentially affected by T. gondii infection across strains. BALB/c mice exhibited increased microglial branching and complexity, while Swiss al-bino mice showed reduced shrunk microglial arbors, diminishing morphological complexity. These findings highlight strain-specific differences in disease progression and inflammatory reg-ulation, indicating lineage-specific mechanisms in inflammatory responses, tolerance, and re-sistance. These elements are critical in devising control measures for toxoplasmosis.

There is now considerable evidence that several infectious agents (viruses, bacteria, or parasites) may play a contributing role in the development of Alzheimer’s disease (AD). The six primary suspects are herpes viruses, spirochetal bacteria, Chlamydia pneumoniae, Porphyromonas gingivalis, mycobacteria, and toxoplasma parasites. Also, some of the antimicrobial and antiviral agents that are used to treat them have shown promise for AD interventions. I describe this evidence and assert it is now time to accelerate clinical trials of these existing drugs, already federally approved, to determine if such treatments can delay, halt, or reverse AD.

Toxoplasmosis is a zoonosis of warm-blooded animals, affecting also humans, caused by Toxo-plasma gondii, an obligate intracellular parasite with a complex biological cycle. Toxoplasmosis is considered a re-emerging zoonosis and an important public health threat, also for the absence, up to now, of efficient vaccines and preventive measures. Sources of transmission to humans are environmental or food-borne, mainly through the consumption of raw and undercooked meat, predominantly of Sus scrofa, considered highly susceptible to T. gondii. Mainly in the last dec-ades, an effective strategy to counter animal infectious diseases was based on the discovery of resistance immuno-genetic markers, possibly to be used for association studies between geno-typic and phenotypic traits and consequently in Marker Assisted Selection. Until now, this gen-otyping approach has never been adopted for T. gondii infection, so this study aimed, for the first time, to fill this gap. In particular, pigs, reared in different farms of Central Italy, were serologically characterized by an ELISA assay performed on diaphragm meat juice. Out of 179 tested animals, 98 resulted seropositive (54.74%), 57 seronegative (31.84%) and 24 doubtful (10.6%), underlining a possible re-emerging diffusion of this protozoan in the investigated areas. Atten-tion was firstly focused on IL-18 gene, encoding for a pro-inflammatory cytokine that plays a key role starting from the upstream steps of the immunity pathway towards T. gondii. A RT-PCR assay followed by Sanger sequencing of IL-18 cDNA was de novo developed. For this interleukin, at this stage, genetic analysis has not highlighted significant polymorphic variations compared to the reference sequence, except for a seropositive animal. However, the outcomes of this pre-liminary innovative study will be investigated in depth analyzing other relevant genetic re-gions and other target genes.

Rodents are known to be reservoirs of Toxoplasma gondii and keep the parasite circulation in the environment. We conducted biomonitoring to assess the role of sylvatic rodents in maintaining T. gondii and to analyse the prevalence and seroprevalence of the parasite in seven wild rodent species. Rodents were collected in our study sites (woodland and open grasslands) located in northeastern Poland and dissected. We collected brain, spleen, blood and serum samples. We applied both molecular (PCR assay, nested-PCR assay) and serological (ELISA and agglutination tests) methods to indicate the best approach for application in the biomonitoring of T. gondii in small mammals. We screened samples from 95 individuals sing PCR assays and found no T. gondii DNA. The agglutination test showed no signal. We found antibodies against T. gondii in 6 sera samples out of 74 analysed (seroprevalence = 8.11% [4.0-17.1]). Our results confirm that rodents participate in the life cycle of T. gondii as reservoirs of this parasite in the sylvatic environment. However, biomonitoring should be performed with the ELISA tests to search for T. gondii antigens, rather than a molecular approach only.