Parasite Toxoplasma Gondii Research Articles

The Dually Localized EF-Hand Domain-Containing Protein TgEFP1 Regulates the Lytic Cycle of Toxoplasma gondii.

The propagation of the obligate intracellular parasite Toxoplasma gondii is tightly regulated by calcium signaling. However, the mechanisms by which calcium homeostasis and fluxes are regulated in this human pathogen are not fully understood. To identify Toxoplasma’s calcium homeostasis network, we have characterized a novel EF-hand domain-containing protein, which we have named TgEFP1. We have determined that TgEFP1 localizes to a previously described compartment known as the plant-like vacuole or the endosomal-like compartment (PLV/ELC), which harbors several proteins related to ionic regulation. Interestingly, partial permeabilization techniques showed that TgEFP1 is also secreted into the parasitophorous vacuole (PV), within which the parasite divides. Ultrastructure expansion microscopy confirmed the unusual dual localization of TgEFP1 at the PLV/ELC and the PV. Furthermore, we determined that the localization of TgEFP1 to the PV, but not to the PLV/ELC, is affected by disruption of Golgi-dependent transport with Brefeldin A. Knockout of TgEFP1 results in faster propagation in tissue culture, hypersensitivity to calcium ionophore-induced egress, and premature natural egress. Thus, our work has revealed an interplay between the PV and the PLV/ELC and a role for TgEFP1 in the regulation of calcium-dependent events.

Epigenetic Reprogramming in Host-Parasite Coevolution: TheToxoplasmaParadigm

Like many intracellular pathogens, the protozoan parasite Toxoplasma gondii has evolved sophisticated mechanisms to promote its transmission and persistence in a variety of hosts by injecting effector proteins that manipulate many processes in the cells it invades. Specifically, the parasite diverts host epigenetic modulators and modifiers from their native functions to rewire host gene expression to counteract the innate immune response and to limit its strength. The arms race between the parasite and its hosts has led to accelerated adaptive evolution of effector proteins and the unconventional secretion routes they use. This review provides an up-to-date overview of how T. gondii effectors, through the evolution of intrinsically disordered domains, the formation of supramolecular complexes, and the use of molecular mimicry, target host transcription factors that act as coordinating nodes, as well as chromatin-modifying enzymes, to control the fate of infected cells and ultimately the outcome of infection.

Seroprevalence of toxoplasmosis in quail birds (Coturnix coturnix) in Baghdad City, Iraq

Toxoplasmosis is a common zoonotic parasitic disease in humans and animals worldwide, caused by the protozoan parasite Toxoplasma gondii. The study designed for detection the prevalence rate of Toxoplasmosis in quail birds (Coturnix coturnix) from different areas in Baghdad city, Iraq (Al- Ghazel souq, Al-Malhani, Al-Hurria, Al Shoula’a and quails farms in Abu-Ghraib Poultry Research Station) by indirect ELISA IgG test and determined the effects of some risk factors (sex, age, areas and months) on this rate during the period from the 1st January 2021, to 30th September 2021. One hundred and fifty sera of quails (75) hens and 
 (75) cocks were examined by indirect IgG Enzyme Linked Immunosorbent Assay (ELISA). The results clarified the total infection rate was 19.33% (29/150) in quails 24% (18/75) hens and 14.66% (11/75) cocks. The higher infection rate 24% (24/100) was recorded in the age group ≤ Maturity period (35 days) ≤ Year (1-2ys), while a lower infection rate 10% (5/50) was found in the age group < Maturity period (35 days). A higher infection rate 41.17% (7/17) was recorded in September, and lower infection rate 5.88% (1/17) was recorded in July.

Toxoplasma gondii Infection and Aggression in Autistic Children.

Toxoplasmosis is an infectious disease caused by the obligatory intracellular parasite Toxoplasma gondii. The main aim of this study was to evaluate a possible relationship between aggression in autistic children with infection by T. gondii. The research design was an analytical (comparative) cross sectional study. The participants included (N = 100) subjects (50 autistic and 50 normal children) between 3 and 12 years old. They were matched for age, socioeconomic status, lack of physical and mental illness. The instruments were preschool aggression scale and enzyme-linked immunosorbent assay procedure to essay the blood sample test. Five milliliters of blood samples were collected to assess the presence of T. gondii infection. The results showed that autistic children had a higher rate of infection by T. gondii than normal children. Furthermore, children infected with T. gondii were more aggressive than the noninfected group. In autistic children, T. gondii infection was significantly higher than in the normal group. Also, autistic children who were infected with the parasite were more aggressive.

Selective Reprogramming of Peritoneal Macrophages by IFN-γ During Acute Toxoplasma gondii Infection

Abstract Host resistance to intracellular pathogens is dependent on the pleiotropic cytokine interferon gamma (IFN-γ) which activates myeloid cells, such as macrophages, and results in pathogen clearance. Macrophages safeguard most regions of the body participating in tissue homeostasis, disease surveillance, pathogen elimination, and resolution of inflammation. The peritoneal cavity is patrolled by two unique subsets of resident macrophages: monocyte-derived small peritoneal macrophages (SPMs) and embryonically-seeded large peritoneal macrophages (LPMs). To determine the roles of SPMs and LPMs during intracellular infections, we infected mice intraperitoneally with the intracellular parasite Toxoplasma gondii, a robust driver of IFN-γ-mediated type 1 immune responses. We observed that T. gondii triggers a distinctive response in LPMs and SPMs responding to parasitic infection. Through the use of neutralizing antibodies, recombinant IFN-γ, and mice conditionally lacking expression of the IFN-γ receptor in macrophages, we have shown that the direct effects of IFN-γ are both required and sufficient for selective reprogramming of peritoneal macrophage subsets in response to T. gondii infection. Molecular mechanisms underlying the macrophage subset-specific effects of IFN-γ were further dissected in vivo and in vitro through imaging and omics approaches. Our results revealed the peritoneal macrophage subset-specific responses to IFN-γ that are essential for host resistance to T. gondii. Supported by the URMC T32 Immunology Training Grant AI00728, NIH R01 GR501266, and the Burroughs Wellcome Fund.

Association of zoonotic protozoan parasites with microplastics in seawater and implications for human and wildlife health

Plastics are widely recognized as a pervasive marine pollutant. Microplastics have been garnering increasing attention due to reports documenting their ingestion by animals, including those intended for human consumption. Their accumulation in the marine food chain may also pose a threat to wildlife that consume species that can accumulate microplastic particles. Microplastic contamination in marine ecosystems has thus raised concerns for both human and wildlife health. Our study addresses an unexplored area of research targeting the interaction between plastic and pathogen pollution of coastal waters. We investigated the association of the zoonotic protozoan parasites Toxoplasma gondii, Cryptosporidium parvum, and Giardia enterica with polyethylene microbeads and polyester microfibers. These pathogens were chosen because they have been recognized by the World Health Organization as underestimated causes of illness from shellfish consumption, and due to their persistence in the marine environment. We show that pathogens are capable of associating with microplastics in contaminated seawater, with more parasites adhering to microfiber surfaces as compared with microbeads. Given the global presence of microplastics in fish and shellfish, this study demonstrates a novel pathway by which anthropogenic pollutants may be mediating pathogen transmission in the marine environment, with important ramifications for wildlife and human health.

Study the relationship between NFKB-p65 and some immunological biomarker in patients infected with Toxoplasma gondii parasite

The study was conducted on 350 aborted women and 30 healthy women who have visited Public Health Laboratory, in Babylon Governorate from August 2021 to February 2022. The current study revealed that serum concentration of NF-KB ,IL-18 (pg/ml), IL-1β (pg/ml) and TNF-α (pg/ml) in patients infected with Toxoplasma gondii were significant increase (P (18. 812 ± 0.185 ng/ml), (474. 12338± 0.906 pg/ml), (15. 41450± 0.218 pg/ml), (25. 4145065284± 0.218232 pg/ml) in compared to the control group (8.515 ± 0.515 ng/ml), (97.107565 ± 0. 700 pg/ml), (4.129558 ± 0. 190 pg/ml), (6.45839 ± 0. 220 pg/ml). The current study has concluded that the infection with T. gondii affects the body's immunity by NF-KB, IL-18, IL-1β and TNF-α. In addition, study was designed to reveal the correlated between NF-KB with IL-18, IL-1β and TNF-α in patients infected with T. gondii. The results of the current study showed the serum concentration of NF-KB was correlated positively and significantly with serum concentration of IL-18, IL-1β and TNF-α.

Molecular Characterization of Toxoplasma gondii in Cats and Its Zoonotic Potential for Public Health Significance.

Toxoplasmosis is a globally distributed disease of warm-blooded animals. It is caused by the opportunistic parasite Toxoplasma gondii (T. gondii). One-third of the global human population is believed to be infected with T. gondii. Cats serve as final host of T. gondii and are the main source of contamination of soil and water. This study aimed to detect genotypes of T. gondii in cats. Fecal samples (n = 400) were collected from districts of South Punjab (Khanewal and Sahiwal), and were processed by polymerase chain reaction (PCR) followed by sequencing and phylogenetic analysis. The obtained oligonucleotide sequences (T. gondii) were submitted to the GenBank database, and the evolutionary tree was constructed using MEGA-X software. Seven fecal samples (3.5%) from cats were positive. Five out of thirteen fecal samples (38.46%) found to be positive for T. gondii with microscopy were confirmed by PCR. After phylogenetic analysis with 3 clonal types and atypical strains, isolates of T. gondii in current study were more closely linked to a typical strain (AF249696). Besides genotyping from cats, seroprevalence from humans and ruminants is still considered to be the best and easiest way to identify the Toxoplasma. Blood samples were collected from sheep and goats (n = 2000 each), and human blood samples (n = 400) were collected from the same vicinity. Seroprevalence was determined using a commercial enzyme-linked immunosorbent assay (ELISA) kit. In Khanewal, the blood samples of 292 goats (29.2%) and 265 sheep (26.5%), and 6 fecal samples from cats (3%) were positive. Out of 200 human blood samples, 52 were positive, with a seroprevalence of 26%. In the Sahiwal district, the blood samples from 49 humans, 235 sheep and 348 goats were positive, with seroprevalence of 24.5%, 23.5% and 34.8%, respectively. The present study revealed the current circulating genotype of T. gondii from cats in the districts Khanewal and Sahiwal and the seroprevalence of the organism in small ruminants and humans living in the same vicinity. Further genotype analyses of the organism from ruminants and humans are needed.

Are foxes (Vulpes spp.) good sentinel species for Toxoplasma gondii in northern Canada?

BackgroundIn changing northern ecosystems, understanding the mechanisms of transmission of zoonotic pathogens, including the coccidian parasite Toxoplasma gondii, is essential to protect the health of vulnerable animals and humans. As high-level predators and scavengers, foxes represent a potentially sensitive indicator of the circulation of T. gondii in environments where humans co-exist. The objectives of our research were to compare serological and molecular assays to detect T. gondii, generate baseline data on T. gondii antibody and tissue prevalence in foxes in northern Canada, and compare regional seroprevalence in foxes with that in people from recently published surveys across northern Canada.MethodsFox carcasses (Vulpes vulpes/Vulpes lagopus, n = 749) were collected by local trappers from the eastern (Labrador and Québec) and western Canadian Arctic (northern Manitoba, Nunavut, and the Northwest Territories) during the winters of 2015–2019. Antibodies in heart fluid were detected using a commercial enzyme-linked immunosorbent assay. Toxoplasma gondii DNA was detected in hearts and brains using a magnetic capture DNA extraction and real-time PCR assay.ResultsAntibodies against T. gondii and DNA were detected in 36% and 27% of foxes, respectively. Detection of antibodies was higher in older (64%) compared to younger foxes (22%). More males (36%) than females (31%) were positive for antibodies to T. gondii. Tissue prevalence in foxes from western Nunavik (51%) was higher than in eastern Nunavik (19%). At the Canadian scale, T. gondii exposure was lower in western Inuit regions (13%) compared to eastern Inuit regions (39%), possibly because of regional differences in fox diet and/or environment. Exposure to T. gondii decreased at higher latitude and in foxes having moderate to little fat. Higher mean infection intensity was observed in Arctic foxes compared to red foxes. Fox and human seroprevalence showed similar trends across Inuit regions of Canada, but were less correlated in the eastern sub-Arctic, which may reflect regional differences in human dietary preferences.ConclusionsOur study sheds new light on the current status of T. gondii in foxes in northern Canada and shows that foxes serve as a good sentinel species for environmental circulation and, in some regions, human exposure to this parasite in the Arctic.Graphical

Methods of Laboratory diagnostics of intracellular protozoan parasite Toxoplasma gondii in pets of the Felidae family

The main source of the spread of the invasive origin and the entry of toxoplasma oocysts into the external environment are pets - cats, infection of all types of mammals is possible. Transmission of the pathogen can occur during contact with animals, as well as when using thermally insufficiently processed meat. The main danger of toxoplasmosis is for pregnant cats (primary infection during pregnancy is associated with the risk of congenital toxoplasmosis and fetal development disorders), as well as with a pronounced decrease in immunity. In domestic pets of the feline family, pathogens of toxoplasmosis are at different stages of development, therefore oocysts can be detected by examining freshly excreted feces by the Fulleborn method or by detecting antibodies in the blood by enzyme immunoassay (ELISA) using the Immunorun Antigen Detection Kit canine Heartworm test system, manufactured by Biogal - Galed labs (Israel). The material for this work was the results of laboratory tests of blood and faecal samples from 73 pets (46 females, 27 males) aged 6 months to 10 years and one-time studies by the Fulleborn method of faecal samples from 109 different-aged pets (69 females, 40 males) examined in 2020-21 in the veterinary clinic of the city of Yakutsk due to other diseases and preventive examination.

Role of NLRP3 in patients infected with Toxoplasma gondii parasite

The study was conducted on 350 aborted women and 30 healthy women who have visited AL-Zahra maternity and paediatrics hospital in AL-Najaf province from November from August to January 2022. This study was designed to determine the effects of T. gondii infection on some parameters such as NLRP3, IL-18, IL-1β and TNF-α , The results showed a significant elevation (P<0.001) in serum concentration of The current study revealed that serum concentration of NLRP3 (ng/ml), IL-18 (pg/ml), IL-1β (pg/ml) and TNF-α (pg/ml) in patients infected with Toxoplasma gondii were significant increase (P (46. 21642 ± 0.524 ng/ml), (474. 12338± 0.906 pg/ml), (15. 41450± 0.218 pg/ml), (25. 4145065284± 0.218232 pg/ml) in compared to the control group (9.701792 ± 0.555 ng/ml), (97.107565 ± 0. 700 pg/ml), (4.129558 ± 0. 190 pg/ml), (6.45839 ± 0. 220 pg/ml). The current study has concluded that the infection with T. gondii affects the body's immunity by NLRP3, IL-18, IL-1β and TNF-α.

Which mass is this? Diagnostic dilemma of an HIV patient presenting with intracranial mass

Patients living with HIV (PLWHA) suffer from many medical condition, neurological complaints being one of the commonest. Intracranial masses are frequently found upon radiological examination on these patients. Differential diagnoses of intracranial mass in these patients vary, with several features overlapping each other, making diagnosis, and thus management, challenging. A patient diagnosed previously with HIV, a woman in her thirties, presented to the ER complaining headache for 2 weeks. Upon examination, she also exhibited left-sided hemiparesis and cranial nerve symptoms. A computed tomography (CT) scan showed multiple contrast-enhancing lesions with meningeal enhancement, which can be attributed to toxoplasmic encephalitis (TE), primary central nervous system lymphoma (PCNSL), progressive multiple leukoencephalopathy (PML), or tuberculous (TB) meningitis. Her toxoplasma serology came up positive, therefore the empirical treatment was focused on eliminating the parasite Toxoplasma gondii, as well as supportive therapy, after which she showed significant improvement in her clinical symptoms as well as brain imaging. Determining the etiology of intracranial mass in HIV patients are not always straightforward; consideration of several factors and administering therapy according to algorithms can deliver good outcome.

In vitro maturation of Toxoplasma gondii bradyzoites in human myotubes and their metabolomic characterization

The apicomplexan parasite Toxoplasma gondii forms bradyzoite-containing tissue cysts that cause chronic and drug-tolerant infections. However, current in vitro models do not allow long-term culture of these cysts to maturity. Here, we developed a human myotube-based in vitro culture model of functionally mature tissue cysts that are orally infectious to mice and tolerate exposure to a range of antibiotics and temperature stresses. Metabolomic characterization of purified cysts reveals global changes that comprise increased levels of amino acids and decreased abundance of nucleobase- and tricarboxylic acid cycle-associated metabolites. In contrast to fast replicating tachyzoite forms of T. gondii these tissue cysts tolerate exposure to the aconitase inhibitor sodium fluoroacetate. Direct access to persistent stages of T. gondii under defined cell culture conditions will be essential for the dissection of functionally important host-parasite interactions and drug evasion mechanisms. It will also facilitate the identification of new strategies for therapeutic intervention.

Development of a droplet digital polymerase chain reaction tool for the detection of Toxoplasma gondii in meat samples

Toxoplasmosis is a zoonotic disease caused by the protozoan parasite Toxoplasma gondii. Infection in humans has usually been related to the consumption of raw, undercooked or cured meat. The aim of this study was to develop a droplet digital polymerase chain reaction (ddPCR)-based assay for the detection and quantification of T. gondii in meat samples. To optimize the ddPCR, T.gondii reference DNA aliquots at five known concentrations: 8000 cg/µl, 800 cg/µl, 80 cg/µl, 8 cg/µl were used. Moreover, results obtained by ddPCR and quantitative PCR (qPCR) were compared using 80 known samples (40 positive and 40 negative), as well as 171 unknown diaphragm tissue samples collected at slaughterhouses. The ddPCR showed a sensitivity of 97.5% and a specificity of 100%, with a detection limit of 8 genomic copy/µl of T. gondii. A nearly perfect agreement (κ = 0.85) was found between results obtained by ddPCR and qPCR for both positive and negative known samples analysed. On the 171 diaphragm tissue samples from field, 7.6% resulted positive by ddPCR and only 1.2% by qPCR. Therefore, this innovative method could be very useful for the detection of T. gondii in meat samples, aiming to prevent human infections.

Epigenetic Modifiers Alter Host Cell Transcription to Promote Toxoplasma Infection.

Given the importance of epigenetic modification, pathogens have found a variety of ways to alter chromatin and affect host gene expression. The apicomplexan parasite Toxoplasma gondii expresses two nuclear targeted secreted effectors TgIST and TgNSM that target the activity of host histone deacetylase regulating corepressor complexes NuRD and NCoR/SMRT, respectively. TgIST and TgNSM are crucial for blocking the host interferon response protecting both the acute and latent stages of the infection. T. gondii represents a unique model organism to study the significance of epigenetic modifications in the regulation of interferon responses and other transcriptional responses at the interface of host-pathogen interaction.

Occurrence of the protozoan parasites Toxoplasma gondii and Cyclospora cayetanensis in the invasive Atlantic blue crab Callinectes sapidus from the Lesina Lagoon (SE Italy)

The occurrence of the protozoan parasites Toxoplasma gondii and Cyclospora cayetanensis was molecularly investigated in the hemolymph, gills, stomach, hepatopancreas and gonads of the eleven invasive Atlantic blue crab Callinectes sapidus from the Lesina Lagoon (Mediterranean Sea). Out of 11 blue crabs, 6 (54.5%) and 4 (36.4%) were found positive to T. gondii and C. cayetanenis, respectively; parasites were found only in the six females analysed, while the remaining five males resulted negative. Moreover, out of 55 tissues samples, 7 (12.7%) and 8 (14.5%) were positive to T. gondii and C. cayetanensis, respectively with hemolymph and gills being the most infected tissues. This is the first report of the presence of protozoan pathogens in wild crab species collected from a Mediterranean lagoon. The present results may provide a baseline reference on microbial infection in the species for invaded Mediterranean waters, and on the potential health risks related with its consumption if eaten raw.

Characterizing the distribution of myosin H in the apical complex of conoid protruded and conoid retracted Toxoplasma gondii

An estimated 1 billion people globally are infected by the parasite Toxoplasma gondii. While most infections are asymptomatic, serious disease can occur in the immunocompromised and in fetuses. Despite the organism’s significance to human health, there are many gaps in our understanding of T. gondii’s basic biology. The parasite uses an apical complex comprised of secretory organelles and proteinaceous structures to drive host-cell invasion and is capable of invading virtually any animal cell. However, fundamental details of the apical complex organization and composition are unknown, with observation made difficult by the fact that the entire complex is approximately a single diffraction-limited volume.

How forced cell entry affects pathogen digestion in phagosomes

Many pathogens, including the parasite Toxoplasma gondii, enter host cells through an active penetration process that is fundamentally different from phagocytosis. When such pathogens infect host cells, they trigger cytoskeletal re-organization at the host-cell plasma membrane to generate physical forces that facilitate their internalization into the intracellular vacuoles. These pathogen-containing vacuoles do not have degradative capacity as normal phagosomes, so the internalized pathogens replicate freely inside for infection.

Eviction notice served on Toxoplasma.

The gene RARRES3 uses an unexpected strategy to eliminate the parasite Toxoplasma gondii from human cells.

Synthesis, characterization and in vitro bioactivity studies of isoindolin‐1‐3‐phosophonate compounds

AbstractIn this work, efficient synthesis of isoindolin‐1‐one‐3‐phosphonates under catalyst‐ and solvent‐free conditions was reported to afford the desired compounds in excellent yields with potent pharmacological properties. The synthesis method involves the preparation of isoindolin‐1‐one‐3‐phosphonates by a “one‐pot” three‐component reaction of 2‐formylbenzoic acid with primary amines and dimethyl phosphite under solvent‐ and catalyst‐free conditions. All new compounds were characterized by 1H NMR, 13C NMR, FT‐IR and elemental analysis techniques. The compounds were investigated for their bioactivities against a group of microorganisms, Leishmania major, Toxoplasma gondii parasites, and the DA‐MB‐231 and MCF‐7 cancer cell lines in vitro. Compound 4a was found to be the most active against L. M. luteus, L. monocytogenes and C. albicans microorganisms, with inhibition zones of 35, 22 and 38 mm, respectively. The compounds were also investigated for their antiparasitic activities, and compounds 4a and 4b were the most active against L. major amastigotes and promastigotes with EC50 < 1 μM. All tested compounds had potent anticancer activity against the MDA‐MB‐231 and MCF‐7 human cell lines with EC50 < 1.5 μM. Compounds 4a and 4b are good drug candidates for antimicrobial, antileishmanial and anticancer drug discovery, and further in vivo studies are highly recommended prior to any clinical trials.