Toxoplasma gondii Infection in Immunocompromised Patients: A Systematic Review and Meta-Analysis

The global seroprevalence of Toxoplasma gondii infection in workers occupationally exposed to animals (1972-2023): a systematic review and meta-analysis

Toxoplasma gondii, a ubiquitous zoonotic parasite infecting warm-blooded animals, poses a significant health threat to workers with occupational animal exposure (WOEA) due to their frequent contact with potential reservoirs. Existing data on T. gondii seroprevalence in the WOEA exhibits substantial global variation. This systematic review and meta-analysis, adhering to PRISMA guidelines, aimed to quantify the global seroprevalence of T. gondii infection among WOEA over the past five decades (1972-2023). We identified 66 eligible studies through a comprehensive search strategy encompassing English publications, with a total sample size of 15,279. A random-effects model with the Freeman-Tukey transformation in STATA v16.0 accounted for the high heterogeneity observed. We estimated the pooled global seroprevalence of T. gondii infection in WOEA at 41% (95% CI: 36-47%). Subgroup analyses revealed significant variations by gender: males (63%) vs. females (37%) (p < 0.05), occupation: non-livestock workers (54%), livestock workers (47%), slaughterhouse workers (44%), and veterinary personnel (27%) (p < 0.05). Geographic trends showed the highest prevalence in Africa (51%), followed by South America (49%), Europe (47%), Australia (43%), Asia (36%), and North America (23%; p < 0.05). Lower prevalence was observed in high-income (39%) and upper-middle-income (38%) countries compared to lower-middle-income (44%) and low-income (48%) countries (p < 0.05). This analysis underscores the high global seroprevalence of T. gondii in the WOEA, highlighting the need for targeted interventions in this high-risk population.

The Prevalence of Toxoplasma gondii in Saudi Arabia (1994-2023): A Systematic Review and Meta-Analysis

Toxoplasmosis is one of the most common parasites affecting humans in diverse populations caused by T. gondii. This study aims to systematically review and analyze the prevalence of T. gondii infection among various population categories in Saudi Arabia. Our search was done in five databases: PubMed, Scopus, Cochrane Library, Embase, and Web of Science to find the relevant studies from inception to November 2023. The pooled prevalence of toxoplasmosis among the total population living in Saudi Arabia was estimated using a random-effect meta-analysis approach, and Comprehensive Meta-Analysis software was utilized for this analysis. Our study included 30 case-control and retrospective studies published from 1994 to 2023 involving 20,699 patients from different regions in the Kingdom of Saudi Arabia. Various cities were included, such as Al-Ahsa, Najran, Riyadh, Arar, Mecca, al Khobar, Mushait, Tabuk, jazan, Hail City, Almadinah Almunawwarah, AL-Ahsa, and Abha; 27 reported outcomes related to IgG seroprevalence, revealing an overall toxoplasmosis prevalence of 27.5% in Saudi Arabia. Fifteen studies that measured IgM seroprevalence found an overall toxoplasmosis prevalence of 2.2%. Specifically for pregnant women, IgG seroprevalence was 28%. Among different age categories, the highest toxoplasmosis prevalence was observed in the group aged 31-45 years, reaching 32.5%, while the lowest prevalence was in the 10-20 years category at 19.3%. Regarding gravidity, the grand multi-gravida group exhibited the highest prevalence at 32.9%, with an upper limit of 47.8%. Furthermore, individuals who consumed freshwater demonstrated a higher incidence than those drinking bottled water, with respective prevalence rates of 33.5% and 29.4%. In conclusion, the prevalence of toxoplasmosis in Saudi Arabia is lower than the global average, with significant variations across different age groups, water sources, and dietary habits. Targeted educational programs and public health interventions are essential to raise awareness and reduce the risk of T. gondii infection. Future research should focus on improving study quality and exploring the broader implications of toxoplasmosis on public health in Saudi Arabia.

Nanospheres as the delivery vehicle: novel application of Toxoplasma gondii ribosomal protein S2 in PLGA and chitosan nanospheres against acute toxoplasmosis

Toxoplasma gondii (T. gondii) is a zoonotic disease that poses great harm to humans and animals. So far, no effective T. gondii vaccine has been developed to provide fully protection against such parasites. Recently, numerous researches have focused on the use of poly-lactic-co-glycolic acid (PLGA) and chitosan (CS) for the vaccines against T. gondii infections. In this study, we employed PLGA and CS as the vehicles for T. gondii ribosome protein (TgRPS2) delivery. TgRPS2-PLGA and TgRPS2-CS nanospheres were synthesized by double emulsion solvent evaporation and ionic gelation technique as the nano vaccines. Before immunization in animals, the release efficacy and toxicity of the synthesized nanospheres were evaluated in vitro. Then, ICR mice were immunized intramuscularly, and immune protections of the synthesized nanospheres were assessed. The results showed that TgRPS2-PLGA and TgRPS2-CS nanospheres could induce higher levels of IgG and cytokines, activate dendritic cells, and promote the expression of histocompatibility complexes. The splenic lymphocyte proliferation and the enhancement in the proportion of CD4+ and CD8+ T lymphocytes were also observed in immunized animals. In addition, two types of nanospheres could significantly inhabit the replications of T. gondii in cardiac muscles and spleen tissues. All these obtained results in this study demonstrated that the TgRPS2 protein delivered by PLGA or CS nanospheres provided satisfactory immunoprotective effects in resisting T. gondii, and such formulations illustrated potential as prospective preventive agents for toxoplasmosis.

First Sero-Molecular Diagnosis of Toxoplasma gondii and Toxocara spp. Infections in the Police Dogs and Their Trainers in Iran

PURPOSE

Toxoplasma gondii (T. gondii) and Toxocara spp. are two types of parasites that can infect humans and various animals, including dogs. Police dogs and their trainers have a vital role in law enforcement, and their health and well-being are crucial for them to effectively carry out their duties. No study has yet been conducted on the prevalence of T. gondii and Toxocara spp. infections among police dogs and their trainers in Iran. The objective of this study was to determine the sero-molecular prevalence of T. gondii and Toxocara spp. infections in police dogs and their trainers in Tehran, the capital of Iran.

METHODS

In Tehran province, the anti-narcotics police have nearly 200 well-trained police dogs. Each dog is assigned a dedicated trainer and upon completing missions, is housed separately in a designated area. In the present study, a total of 150 samples were gathered. These included 50 blood samples from randomly selected police dogs, 50 fecal samples from the same dogs, and 50 blood samples from their trainers. The Modified Agglutination Test (MAT) was performed to detect T. gondii antibodies in dog blood samples and the ELISA system was utilized to identify anti-Toxoplasma and anti-Toxocara antibodies in the sera of the dog trainers. A specific segment of the SAG2 and ITS genes were amplified via nested-PCR in order to molecularly detect T. gondii in human blood samples and Toxocara spp. in dog fecal samples.

RESULTS

Regarding serological findings, the prevalence of T. gondii in dog and human blood samples was 4% (2/50) and 10% (5/50), respectively. According to reports, the seroprevalence of Toxocara spp. in human blood samples was 6% (3/50). No statistically significant association was found between the prevalence of the examined parasites and variables (age, sex, and breed) in dogs, as well as the age variable in military personnel. Molecular findings showed that out of the 50 dog fecal samples and 50 human blood samples, there was no presence of Toxocara spp. and T. gondii, respectively.

CONCLUSION

Understanding the prevalence of parasitic infections helps public health officials assess the risk to human and animal populations. This information can guide the development of prevention and control measures to reduce the spread of these infections. Overall, the prevalence of parasitic infections, particularly T. gondii and Toxocara spp., in police dogs and their trainers remains uncertain and necessitates further in-depth research.

TgVax452, an epitope-based candidate vaccine targeting Toxoplasma gondii tachyzoite-specific SAG1-related sequence (SRS) proteins: immunoinformatics, structural simulations and experimental evidence-based approaches

BACKGROUND

The highly expressed surface antigen 1 (SAG1)-related sequence (SRS) proteins of T. gondii tachyzoites, as a widespread zoonotic parasite, are critical for host cell invasion and represent promising vaccine targets. In this study, we employed a computer-aided multi-method approach for in silico design and evaluation of TgVax452, an epitope-based candidate vaccine against T. gondii tachyzoite-specific SRS proteins.

METHODS

Using immunoinformatics web-based tools, structural modeling, and static/dynamic molecular simulations, we identified and screened B- and T-cell immunodominant epitopes and predicted TgVax452's antigenicity, stability, safety, adjuvanticity, and physico-chemical properties.

RESULTS

The designed protein possessed 452 residues, a MW of 44.07 kDa, an alkaline pI (6.7), good stability (33.20), solubility (0.498), and antigenicity (0.9639) with no allergenicity. Comprehensive molecular dynamic (MD) simulation analyses confirmed the stable interaction (average potential energy: 3.3799 × 106 KJ/mol) between the TLR4 agonist residues (RS09 peptide) of the TgVax452 in interaction with human TLR4, potentially activating innate immune responses. Also, a dramatic increase was observed in specific antibodies (IgM and IgG), cytokines (IFN-γ), and lymphocyte responses, based on C-ImmSim outputs. Finally, we optimized TgVax452's codon adaptation and mRNA secondary structure for efficient expression in E. coli BL21 expression machinery.

CONCLUSION

Our findings suggest that TgVax452 is a promising candidate vaccine against T. gondii tachyzoite-specific SRS proteins and requires further experimental studies for its potential use in preclinical trials.

Toxoplasma infection induces an aged neutrophil population in the CNS that is associated with neuronal protection

BACKGROUND

Infection with the protozoan parasite Toxoplasma gondii leads to the formation of lifelong cysts in neurons that can have devastating consequences in the immunocompromised. In the immunocompetent individual, anti-parasitic effector mechanisms and a balanced immune response characterized by pro- and anti-inflammatory cytokine production establishes an asymptomatic infection that rarely leads to neurological symptoms. Several mechanisms are known to play a role in this successful immune response in the brain including T cell production of IFNγ and IL-10 and the involvement of CNS resident cells. This limitation of clinical neuropathology during chronic infection suggests a balance between immune response and neuroprotective mechanisms that collectively prevent clinical manifestations of disease. However, how these two vital mechanisms of protection interact during chronic Toxoplasma infection remains poorly understood.

MAIN TEXT

This study demonstrates a previously undescribed connection between innate neutrophils found chronically in the brain, termed "chronic brain neutrophils" (CBNeuts), and neuroprotective mechanisms during Toxoplasma infection. Lack of CBNeuts during chronic infection, accomplished via systemic neutrophil depletion, led to enhanced infection and deleterious effects on neuronal regeneration and repair mechanisms in the brain. Phenotypic and transcriptomic analysis of CBNeuts identified them as distinct from peripheral neutrophils and revealed two main subsets of CBNeuts that display heterogeneity towards both classical effector and neuroprotective functions in an age-dependent manner. Further phenotypic profiling defined expression of the neuroprotective molecules NRG-1 andErbB4 by these cells, and the importance of this signaling pathway during chronic infection was demonstrated via NRG-1 treatment studies.

CONCLUSIONS

In conclusion, this work identifies CBNeuts as a heterogenous population geared towards both classical immune responses and neuroprotection during chronic Toxoplasma infection and provides the foundation for future mechanistic studies of these cells.

In Silico Analysis of the ROP29 Protein as a Vaccine Candidate Against Toxoplasma gondii

The progression of Toxoplasma gondii (T. gondii) invasion is aided by rhoptry proteins (ROPs), which are also crucial for the parasite's survival in host cells. In this study, in silico analysis was performed to examine the various aspects of the ROP29 protein, such as physicochemical properties, potential T- and B-cell epitopes, and other significant features. The research revealed that there were 55 possible sites for posttranslational modification in the ROP29 protein. The secondary structure of the ROP29 protein consists of a random coil, an alpha-helix, and an extended strand, which account for 49.69%, 36.81%, and 13.50%, respectively. Moreover, a number of putative T- and B-cell epitopes for ROP29 were found. The Ramachandran plot showed that 88.91% (crude model) and 97.54% (refine model) of the amino acid residues were located in the favored regions. Also, the testing of this protein's antigenicity and allergenicity showed that it was nonallergenic and immunogenic. Our results suggested that employing in silico tools to apply structural and functional predictions to the ROP29 protein can lower the likelihood that laboratory investigations will fail. This research served as a crucial foundation for further research. More research is required in the future in suitable animal model employing ROP29 alone or in combination with other antigens.

Toxoplasma gondii in Wild Boars (Sus scrofa) in Germany: Serological Screening from Thuringia

Game meat is an important source of meat borne parasitic infections. Due to its omnivorous diet, the wild boar is an important host of zoonotic parasites such as Toxoplasma gondii. T. gondii can cause severe to fatal disease in immunosuppressed patients, as well as congenital disorders in foetus and neonates. Consumption of undercooked infected meat is a main source of T. gondii infection. Information about the risk of toxoplasmosis through game meat is scarce. We collected serum samples from 42 wild boars from the federal state of Thuringia (Germany) between December 2017 and February 2018. Identification of anti-T. gondii IgG antibodies was conducted using a commercial indirect ELISA kit. Seropositivity was confirmed in 18 of the 42 samples (37.50%). From these, the highest seroprevalence was found in adult animals. This study joins another single database from wild boars in Brandenburg. The necessity of a country-wide database regarding T. gondii prevalence in wild boar and other game meat is pivotal for a profound risk analysis with its consequential impact in future mean hygiene policies.

Re-Emerging, Under-Recognized Zoonotic, and Neglected Tropical Diseases in Hawai'i

Hawai'i, the United States' most western geographic state in the Pacific, lies between the North and South American continents and the Indo-Pacific regions, including Japan. The tropical environmental conditions of the Hawaiian Islands provide favorable ecosystems for various infectious pathogens, their vectors, and reservoirs. This creates an environment conducive to the transmission of zoonotic diseases affecting both humans and animals. Hawai'i has experienced an increase in dengue, leptospirosis, and murine typhus outbreaks. Furthermore, toxoplasmosis and neuroangiostrongyliasis cases remain prevalent throughout the state, and the putative presence of autochthonous Zika cases identified in a retrospective study may be of national public health concern. Understanding the factors that affect the transmission and distribution of zoonoses is necessary to identify at-risk locations and populations. The One Health approach seeks to understand, report, and interpret these factors and requires collaboration between private and governmental institutions. One Health should focus on neglected tropical diseases (NTD) and prioritize development of interventions to control and prevent the transmission of diseases that spread between animals and humans. This review focuses on the epidemiological and clinical characteristics of under-recognized zoonotic and NTD affecting Hawai'i, including leptospirosis, murine typhus, neuroangiostrongyliasis, toxoplasmosis, dengue, and Zika.

Synthesis and In vitro evaluation of bichalcones as novel anti-toxoplasma agents

Toxoplasmosis is a zoonotic disease caused by Toxoplasma gondii, an apicomplexan parasite that infects approximately a third of the world's human population. This disease can cause serious complications during pregnancy and can be fatal in immunocompromised hosts. The current treatment options for toxoplasmosis face several limitations. Thus, to address the urgent medical need for the discovery of novel anti-toxoplasma potential drug candidates, our research focused on exploring a series of monomeric and dimeric chalcones, polyphenolic molecules belonging to the class of flavonoids. Chalcones 1aa-1bg and axially chiral A-A'-connected bichalcones 2aa-2bg were evaluated in vitro against the proliferation of the parasite in a cell-based assay. A comparison of the efficacy demonstrated that, in several cases, bichalcones exhibited increased bioactivity compared to their corresponding monomeric counterparts. Among these compounds, a bichalcone with a phenyl substituent and a methyl moiety 2ab showed the most potent and selective inhibitory activity in the nanomolar range. Both enantiomers of this bichalcone were synthesized using an axially chiral biphenol building block. The biaryl bond was forged using Suzuki cross-coupling in water under micellar catalysis conditions. Separation of the atropisomers of this biphenol building block was conducted by chiral HPLC on a preparative scale. The biological evaluation of the enantiomers revealed that the (R a)-enantiomer (R a)-2ab is the eutomer. These studies suggest that bichalcones may be important drug candidates for further in vivo evaluations for the discovery of anti-toxoplasma drugs.

In silico study to explore the mechanism of Toxoplasma-induced inflammation and target therapy based on sero and salivary Toxoplasma

We aimed to assess salivary and seroprevalence of Toxoplasma immunoglobulins in risky populations and evaluate drug docking targeting TgERP. A cross-sectional study was conducted in Alexandria University hospitals' outpatient clinics. 192 participants were enrolled from September 2022 to November 2023. Anti-Toxoplasma IgG and IgM were determined in serum and saliva by ELISA. An in-Silico study examined TgERP's protein-protein interactions (PPIs) with pro-inflammatory cytokine receptors, anti-inflammatory cytokine, cell cycle progression regulatory proteins, a proliferation marker, and nuclear envelope integrity-related protein Lamin B1. Our findings revealed that anti-T. gondii IgG were detected in serum (66.1%) and saliva (54.7%), with 2.1% of both samples were positive for IgM. Salivary IgG had 75.59% sensitivity, 86.15% specificity, 91.40% PPV, 64.40% NPP, 79.17% accuracy and fair agreement with serum IgG. On the other hand, the sensitivity, specificity, PPV, NPV, and accuracy in detecting salivary IgM were 75.0%, 99.47%, 75.0%, 99.47%, and 98.96%. AUC 0.859 indicates good discriminatory power. Examined synthetic drugs and natural products can target specific amino acids residues of TgERP that lie at the same binding interface with LB1 and Ki67, subsequently, hindering their interaction. Hence, salivary samples can be a promising diagnostic approach. The studied drugs can counteract the pro-inflammatory action of TgERP.

Anti-Toxoplasma gondii activity of rose hip oil-solid lipid nanoparticles

Toxoplasma gondii is a highly prevalent pathogen, reported from almost all geographical regions of the world. Current anti-T. gondii drugs are not effective enough in immunocompromised patients, encephalitis, chorioretinitis, and congenital toxoplasmosis. Therefore, the prescription of these drugs has been limited. Rose hip oil (RhO) is a natural plant compound, which shows antibacterial, anticancer, and anti-inflammatory activities. In the current study, the anti-T. gondii and cell toxicity effects of solid lipid nanoparticles (SLNs) loaded by RhO (RhO-SLNs) were evaluated. Emulsification sonicated-homogenization method was used to prepare SLNs. RhO-SLNs were characterized, and their anti-T. gondii and cell toxicity effects were evaluated using in vitro analyses. The particle size and the zeta potential of the nanoparticles were 152.09 nm and -15.3 mV nm, respectively. The entrapment efficiency percentage was 79.1%. In the present study, the inhibitory concentration (IC)50 against T. gondii was >1 μg/mL (p-value <.0001). The cell toxicity assay showed cytotoxicity concentration (CC)50 >10 mg/mL (p-value = .017). In addition, at least 75% of T. gondii-infected Vero cells remained alive at concentrations >10 mg/mL. The concentration of 1 mg/mL showed highest anti-Toxoplasma activity and lowest cell toxicity against the Vero cell. Our findings suggest that carrying natural plant compounds with SLNs could be considered an effective option for treatment strategies against T. gondii infections.

Molecular prevalence of Toxoplasma gondii and Trypanosoma evansi in recently calved female cattle from Phayao, Thailand

Background and Aim

Toxoplasma gondii and Trypanosoma evansi, the zoonotic protozoa responsible for toxoplasmosis and trypanosomiasis, are significant threats to the productivity and financial stability of livestock farming. T. gondii can be transmitted horizontally through ingestion of fecal oocysts and T. evansi through arthropod vectors. In addition, both species can be transmitted from mother to fetus through the placenta. This study aimed to assess the molecular prevalence of T. gondii and T. evansi transplacental-transmitted protozoans and to identify the epidemiological risk factors in recently calved female cattle across Phayao, Thailand.

Materials and Methods

We collected 106 bovine placentas from beef and dairy cow full-term pregnancies in Phayao, Thailand. T. gondii and T. evansi DNA were detected using targeted B1 gene and expression site-associated gene (ESAG) species-specific polymerase chain reaction (PCR), respectively.

Results

Forty-three placentas were positive for T. gondii B1 PCR, whereas only one was positive for T. evansi ESAG PCR, resulting in an overall prevalence of transplacental-transmitted protozoan infection of 41.5% (44/106). The prevalence of T. gondii and T. evansi was 40.6% (43/106) and 0.9% (1/106), respectively. No significant correlation was found between T. gondii infection and various risk factors, including locality, age, and cattle type.

Conclusion

The prevalence of transplacental-transmitted protozoan T. gondii infection was high among female cattle in Phayao, Thailand, whereas the prevalence of T. evansi infection was notably lower. Although the conventional modes of transmission differ between these two parasites, the transplacental transmission of T. evansi and especially T. gondii may play a crucial role in the persistence of these protozoan species in this area.

Toxoplasma gondii seroprevalence in the Iranian blood donors: A systematic review and meta-analysis

Background

The present systematic review and meta-analysis was done to assess the rate of Toxoplasma gondii (T. gondii) exposure among Iranian healthy blood donors.

Methods

We searched four English (PubMed, Scopus, Web of Science, and Science Direct) and two Persian databases (Magiran and SID) as well as Google Scholar as a specialized article search engine using specific keywords for relevant papers from the inception up to November 30, 2023.

Results

In total, 19 studies enrolling 8226 apparently healthy blood donors were examined regarding T. gondii-specific IgG and/or IgM antibodies, among which 2666 [32.9% (95% CI: 25.3%-41.6%)], 168 [1.4% (95% CI: 0.9%-2.1%)], and 83 [1.7% (95% CI: 1.3%-2.1%)] subjects were seropositive regarding IgG, IgM, and both IgG/IgM antibodies, respectively. Five risk factors were significantly associated with T. gondii seroprevalence, including gender (OR = 1.98; 95% CI: 1.52-2.58; P < 0.001), contact with cat (OR = 2.41; 95% CI: 1.70-3.41; P < 0.001), contact with soil (OR = 2.83; 95% CI: 1.07-7.45; P = 0.035), consuming raw/undercooked meat (OR = 1.95; 95% CI: 1.03-3.70; P = 0.039), and raw/unwashed vegetables (OR = 1.70; 95% CI: 1.25-2.31; P = 0.001).

Conclusion

A moderate rate of T. gondii exposure was found in the Iranian blood donors, with the association of several risk factors, including gender, contact with cat, contact with soil, consumption of unwashed vegetables and/or undercooked meat. Still, more studies are recommended regarding T. gondii exposure among blood donors in Iran.

Zinc Oxide and Magnesium-Doped Zinc Oxide Nanoparticles Ameliorate Murine Chronic Toxoplasmosis

Toxoplasma gondii causes a global parasitic disease. Therapeutic options for eradicating toxoplasmosis are limited. In this study, ZnO and Mg-doped ZnO NPs were prepared, and their structural and morphological chrematistics were investigated. The XRD pattern revealed that Mg-doped ZnO NPs have weak crystallinity and a small crystallite size. FTIR and XPS analyses confirmed the integration of Mg ions into the ZnO framework, producing the high-purity Mg-doped ZnO nanocomposite. TEM micrographs determined the particle size of un-doped ZnO in the range of 29 nm, reduced to 23 nm with Mg2+ replacements. ZnO and Mg-doped ZnO NPs significantly decreased the number of brain cysts (p < 0.05) by 29.30% and 35.08%, respectively, compared to the infected untreated group. The administration of ZnO and Mg-doped ZnO NPs revealed a marked histopathological improvement in the brain, liver, and spleen. Furthermore, ZnO and Mg-doped ZnO NPs reduced P53 expression in the cerebral tissue while inducing CD31 expression, which indicated a protective effect against the infection-induced apoptosis and the restoration of balance between free radicals and antioxidant defense activity. In conclusion, the study proved these nanoparticles have antiparasitic, antiapoptotic, and angiogenetic effects. Being nontoxic compounds, these nanoparticles could be promising adjuvants in treating chronic toxoplasmosis.

Prevalence of Toxoplasma gondii IgG Antibodies and Associated Risk Factors in Psychiatric Patients from Western Romania: A Cross-Sectional Study

Infection with the coccidian parasite Toxoplasma gondii was associated with an increased risk of several mental disorders. We conducted a case-control study of 464 consecutive psychiatric patients and assessed the prevalence of IgG antibodies against T. gondii and the potential risk factors associated with infection. T. gondii-specific antibodies were determined using a chemiluminescence assay. A questionnaire was utilized to assess the potential correlation between risk factors and Toxoplasma gondii seropositivity. IgG antibodies were found in 325 (70.04%) of the patients. We observed a higher likelihood of positive IgG antibodies against Toxoplasma gondii in older individuals, patients residing in rural areas, and females. We also noted associations between Toxoplasma gondii infection and certain risk factors, like activities that involve contact with soil, low-income levels, and limited educational attainment. Our findings indicate a high prevalence of T. gondii infection among psychiatric patients from Western Romania and provide new information regarding the potential risk factors associated with T. gondii in this population group. This study may serve as a foundation for future research and the development of preventive strategies.

Fulminant Pneumonia Due to Reactivation of Latent Toxoplasmosis in a Cat-A Case Report

Toxoplasma (T.) gondii is an obligate intracellular parasite with felids, including domestic cats, as definitive hosts. In immunocompetent individuals, T. gondii infection is usually asymptomatic. However, under immunosuppression, it may have severe pathological impacts, which often result from the reactivation of a chronic infection. In this case study, a 21-month-old female domestic shorthair cat-diagnosed with primary immune-mediated hemolytic anemia three months prior and treated with cyclosporine and prednisolone-presented with acute tachypnea, dyspnea, diarrhea, and anorexia. Thoracic radiography suggested severe pneumonia. Testing for Mycoplasma spp., Anaplasma spp., Ehrlichia spp., and lungworm infection was negative. Serology for T. gondii revealed seroconversion of IgG, but not of IgM, indicating previous exposure to T. gondii. The cat remained stable but tachypneic for three days, followed by an acute onset of dyspnea and clinical deterioration, after which euthanasia was elected. Numerous protozoa were present in a postmortem transtracheal bronchoalveolar lavage and fine-needle aspiration of the lung. Microsatellite typing classified the extracted DNA as T. gondii type II variant TgM-A. This case demonstrates that T. gondii reactivation, leading to fulminant pneumonia, can be a sequela of immunosuppressive treatment in cats and should, therefore, be considered as a differential diagnosis in immunosuppressed cats with acute-onset respiratory signs. Rapid diagnosis may prevent fatal consequences.

Anti-Toxoplasma gondii Antibodies in European Residents: A Systematic Review and Meta-Analysis of Studies Published between 2000 and 2020

Toxoplasmosis has a major impact on animal and public health. Information regarding the seroprevalence of human Toxoplasma gondii infections from a European perspective has not yet been compiled to date. Thus, the present review summarized available resident data from the period 2000-2020. The overall seroprevalence of anti-T. gondii IgG was 32.1%, with great variability between countries (n = 30). The subgroup analysis identified different pooled prevalence data depending on the geographic area (p < 0.0001), target population (p = 0.0147), and serological diagnosis assays used (p = 0.0059). A high heterogeneity (I2 = 100%, p < 0.001; Q = 3.5e+05, d.f. = 135, p < 0.001) and degree of publication bias (Egger's test = 6.14, p < 0.001) were observed among the 134 studies considered. The occurrence of anti-T. gondii IgM, which was reported in 64.7% of studies, reached a pooled seroprevalence of 0.6%. In addition, among the eight main risk factors identified, "contact with soil", "consumption of undercooked beef", and "intake of unwashed vegetables" were the most significantly associated with infections. The fact that one-third of the European population has been exposed to T. gondii justifies extra efforts to harmonize surveillance systems and develop additional risk-factor analyses based on detailed source attribution assessment.

Human neutrophil extracellular traps do not impair in vitro Toxoplasma gondii infection

Introduction

Toxoplasma gondii, responsible for causing toxoplasmosis, is a prevalent food and waterborne pathogen worldwide. It commonly infects warm-blooded animals and affects more than a third of the global human population. Once ingested, the parasite enters the host's small intestine and rapidly disseminates throughout the body via the bloodstream, infiltrating various tissues. Leukocyte-driven responses are vital against T. gondii, with neutrophils playing a dual role: swiftly recruited to infection sites, releasing inflammatory mediators, and serving as a replication hub and Trojan horses, aiding parasite spread. Neutrophils from various hosts release extracellular traps (NETs) against the protozoan. However, gaps persist regarding the mechanisms of NETs production to parasite and their significance in infection control. This study investigates the interplay between human neutrophils and T. gondii, exploring dynamics, key molecules, and signaling pathways involved in NETs production upon protozoan challenge.

Methods and Results

Using confocal and electron microscopy, live cell imaging, pharmacological inhibitors, and DNA quantification assays, we find that human neutrophils promptly release both classical and rapid NETs upon pathogen stimulation. The NETs structure exhibits diverse phenotypes over time and is consistently associated with microorganisms. Mechanisms involve neutrophil elastase and peptidylarginine deiminase, along with intracellular calcium signaling and the PI3K pathway. Unexpectedly, human traps do not diminish viability or infectivity, but potentially aid in capturing parasites for subsequent neutrophil phagocytosis and elimination.

Discussion

By revealing NETs formation mechanisms and their nuanced impact on T. gondii infection dynamics, our findings contribute to broader insights into host-pathogen relationships.

Establishment and application of an iELISA detection method for measuring apical membrane antigen 1 (AMA1) antibodies of Toxoplasma gondii in cats

BACKGROUND

Diseases caused by Toxoplasma gondii (T. gondii) have introduced serious threats to public health. There is an urgent need to develop a rapid detection method for T. gondii infection in cats, which are definitive hosts. Recombinant apical membrane antigen 1 (rAMA1) was produced in a prokaryotic expression system and used as the detection antigen. The aim of this study was to evaluate and optimize a reliable indirect enzyme-linked immunosorbent assay (iELISA) method based on rAMA1 for the detection of antibodies against T. gondii in cats.

RESULTS

The rAMA1-iELISA method was developed and optimized by the chessboard titration method. There were no cross-reactions between T. gondii-positive cat serum and positive serum for other pathogens, indicating that rAMA1-iELISA could only detect T. gondii in most cases. The lowest detection limit of rAMA1-iELISA was 1:3200 (dilution of positive serum), and the CV of repeated tests within batches and between batches were confirmed to be less than 10%. The results of 247 cat serum samples detected by rAMA1-iELISA (kappa value = 0.622, p < 0.001) were in substantial agreement with commercial ELISA. The ROC curve analysis revealed the higher overall check accuracy of rAMA1-iELISA (sensitivity = 91.7%, specificity = 93.6%, AUC = 0.956, 95% CI 0.905 to 1.000) than GRA7-based iELISA (sensitivity = 91.7%, specificity = 85.5%, AUC = 0.936, 95% CI 0.892 to 0.980). Moreover, the positive rate of rAMA1-iELISA (6.5%, 16/247) was higher than that of GRA7-based iELISA (3.6%, 9/247) and that of commercial ELISA kit (4.9%, 12/247).

CONCLUSION

The iELISA method with good specificity, sensitivity, and reproducibility was established and can be used for large-scale detection of T. gondii infection in clinical cat samples.

Seroprevalence of Anti-Toxoplasma gondii Antibodies among Patients with Cancer at Hiwa Cancer Hospital in Sulaimani City, Kurdistan Region, Iraq

Background

Toxoplasma gondii is an opportunistic protozoan parasite that causes a life-threatening disease - toxoplasmosis - in immunocompromised individuals, including patients with cancer. This prospective cross-sectional study set out to determine the prevalence of toxoplasmosis in patients with cancer compared with that of healthy individuals.

Methods

A prospective cross-sectional study was conducted in Sulaimani City of Iraq from November 2019 to May 2020. Anti-T. gondii IgG and IgM antibodies were measured in the blood samples of 113 patients with cancer (80 with solid organ tumors and 33 with haematological malignancies) entered to Hiwa Cancer Hospital and 82 healthy controls, who were referred to the Directorate of Blood Transfusion for blood donation, using chemiluminescence microparticle immunoassay (CMIA).

Results

The prevalence of anti-T. gondii IgG was 39.8% in the patient group and 24.4% in the control group, which amounted to a significant difference (P = 0.024). Only one case of anti-T. gondii IgM positivity was observed in the patient group, and no IgM seropositivity was reported in the control group. Moreover, the seroprevalence of anti-T. gondii IgG was non-significantly higher (P = 0.102) in the patients with haematological malignancies (51.5%) than in those with solid organ tumors (35%). Occupation was the only risk factor which had a significant association with T gondii infection (odds ratio [OR]: 1.3, 95% confidence interval [CI]: 0.6746163 - 2.4282788, P = 0.029).

Conclusion

The prevalence of T. gondii infection is higher in patients with cancer than in healthy individuals. Therefore, T. gondii screening in patients with cancer is recommended.

Ocular Toxoplasmosis

INTRODUCTION

Ocular toxoplasmosis is the leading cause of posterior uveitis worldwide, affecting individuals acrossdifferent age groups. The key to reducing vision loss includes prompt diagnosis and treatment. However, despite the prevalence of ocular toxoplasmosis, there has been little consensus regarding its pathophysiology,clinical features, diagnosis, and especially management.

METHODS

The data sources were literature reviews, including Pub Med and Medline databases. Search terms included toxoplasmosis, retinitis, vasculitis, vitritis, uveitis alone or in combination with, serum, aqueous, vitreous eye, ocular and review.

RESULTS

In this review paper, we have sought to provide an overview of the pathophysiology, epidemiology, and clinical features of the disease, both based on current literature and our own clinical experience. We have also discussed the use of serology, ocular fluid, and ophthalmic investigations that could further facilitate the diagnosis of ocular toxoplasmosis.Different management strategies have been reported worldwide, including newer approaches such as local therapy.

CONCLUSION

A better understanding of critical aspects of ocular toxoplasmosis will hopefully lead to reduced morbidity, including blindness associated with this condition.

Ivermectin modulated cerebral γ-aminobutyric acid (GABA) and reduced the number of chronic Toxoplasma gondii cysts significantly in the brains of immunocompromised mice

Disruption of GABAergic signaling could exaggerate the inflammatory reaction associated with Toxoplasma gondii infection, as well as produce neurophysiological consequences including seizures that occur within the brain tissues. The current study aimed to evaluate the efficacy of ivermectin (IVM) in treating latent cerebral toxoplasmosis and define its role in the neuromodulation of cerebral tissue GABA expression, conducted in an immunocompromised dexamethasone-treated mouse model infected with the ME49 Toxoplasma strain. The control (non-infected non-treated) group showed a mean of 22.1 ± 0.71 for local expression of GABA. Significantly lower expression (3.78 ± 1.38) was recorded in the infected non-treated group (p ≤ 0.05). On the contrary, a significantly higher expression was reported in the group infected and treated with IVM than in the infected non-treated group (19.8 ± 0.8). While the infected spiramycin (SP)-treated group reported a significantly lower level than the control. Non-infected groups that received only IVM or SP recorded 22.3 ± 0.45 and 22 ± 0.89 respectively with no significant difference. IVM is shown in this work, not only to reduce the size and the number of Toxoplasma cystic lesions within the brain significantly with a reduction rate of 68.85% but to also increase the level of GABA local expression significantly in addition to improving cerebral histopathology. Thus, IVM by its ability to modulate GABA expression may improve such clinical situations, if used as a treatment either exclusively or in combination with other medications.

Latent Toxoplasmosis among Breast Cancer Patients in Jahrom, South of Iran

Objective

Reactivation of latent toxoplasmosis is the main cause of severe infection among immunocompromised patients, including patients with cancer. Hence, this study is aimed at screening the status of Toxoplasma gondii infection among breast cancer patients by serological and molecular methods and determining their associated risk factors in Jahrom County, Fars Province, south of Iran.

Methods

One hundred and seven women with breast cancer (aged 34 to 80 years) were screened for anti-T. gondii antibodies (IgG and IgM) during 2019-2020. A questionnaire regarding demographic factors was filled out by participants. Molecular detection was performed by polymerase chain reaction (PCR) using the primer pair targeting the repetitive element (RE) gene of T. gondii. The risk factors and demographic data were analyzed by SPSS software (ver. 20, Chicago, IL, USA) using the Chi-squared test.

Results

Anti-T. gondii IgG was detected in 45.8% (49/107) of the patients, which indicates latent infection, but anti-T. gondii IgM and PCR were negative in all samples. Demographic factors revealed a statistically significant increased T. gondii seropositivity among nonmenopause cancer patients (P < 0.0005), patients without previous breast cancer (P = 0.0001), and human epidermal growth factor receptor 2- (HER2-) negative patients (P = 0.00002). As such, patients with a history of previous abortions and who were at stages II, III, and IIII of cancer had higher seropositivity rates than patients without a history of previous abortions or who were at stage I cancer, but the statistical analysis was not significant. We did not find a statistically significant association between T. gondii seropositivity and other risk factors of toxoplasmosis (e.g., education level, type of water source, washing raw fruits and vegetables, consumption of raw or undercooked meat, and contact with soil, cats, and domestic animal).

Conclusion

A high seroprevalence rate of latent T. gondii infection was detected among patients with breast cancer; hence, these patients may be at high risk for reactivation of latent infection. Screening of T. gondii infection is recommended to detect active infection among patients with malignancies.

Global seroprevalence of Toxoplasma gondii infection among patients with mental and neurological disorders: A systematic review and meta-analysis

Background and Aim

Toxoplasmosis is the most widespread zoonotic disease that affects one-third of the world's population, and imposes a major public health problem worldwide. This study aimed to assess the prevalence of toxoplasmosis among patients with neuropsychiatric patients.

Methods

Electronic databases PubMed, Google Scholar, Web of Science, Research Gate, and Scopus were thoroughly searched from February to March 2022 to identify all relevant studies. The quality of studies was evaluated using the Newcastle-Ottawa quality scale for case-control and cross-sectional studies. Statistical analysis was done using STATA version 12 software. A random effect model was used to compute the global pooled seroprevalence of Toxoplasma gondii infection. Heterogeneity was quantified by using I 2 value. Subgroup analysis was done, and publication bias was assessed using a funnel plot and Egger's test.

Result

Of 1250 studies, 49 containing 21,093 participants and conducted in 18 countries were included. The global pooled seroprevalence of T. gondii IgG antibody was 38.27% (95% CI: 32.04-44.9) among neuropsychiatric patients and 25.31% (95% CI: 21.53-29.08) in healthy controls with substantial heterogeneity of 98.3%. The prevalence of T. gondii IgG antibody was higher in males (17.52%) than in females (12.35%) neuropsychiatric patients. The highest pooled prevalence of T. gondii IgG antibody was in Europe (57%) followed by Africa (45.25%) and Asia (43%). Time based analysis showed the highest pooled prevalence of T. gondii IgG antibody in 2012-2016 (41.16%).The global pooled seroprevalence T. gondii IgM antibody among neuropsychiatric patients and healthy controls was 6.78% (95% CI: 4.87-8.69) and 3.13% (95% CI: 2.02-4.24), respectively.

Conclusion

The pooled prevalence of chronic and acute T. gondii infection among neuropsychiatric patients was 38.27% and 6.78%, respectively. This showed a high burden of toxoplasmosis among neurological and psychiatric patients and urges routine screening of those patients and providing appropriate treatment. It also indicates the need for different stakeholders to develop targeted prevention and control strategies for T. gondii infection.

The role of Curcuma longa essential oil in controlling acute toxoplasmosis by improving the immune system and reducing inflammation and oxidative stress

Background

Chemotherapy with synthetic drugs is the principal approach for toxoplasmosis treatment; however, recent studies reported the limitations and adverse side effects of these chemical drugs.

Objective

This study aimed to examine the in vitro and in vivo effects of Curcuma longa essential oil (CLE) against the Toxoplasma gondii RH strain.

Methods

The in vitro effect of different concentrations of CLE on T. gondii tachyzoites was assessed by cell viability assay. Flow cytometry and apoptosis analysis were performed, and nitric oxide production by CLE was also evaluated in tachyzoites. BALB/c mice were orally treated with various doses (1.25, 2.5, and 5 mg·kg^-1·day^-1) of CLE for 2 weeks. After the induction of acute toxoplasmosis in the mice, their survival rate and the mean number of peritoneal parasites were checked. The hepatic level of antioxidant enzymes and oxidative stress markers was evaluated by commercial kits. The mRNA expression level of proinflammatory cytokines such as interleukin 1-beta (IL-1β) and interferon-gamma (IFN-γ) was evaluated by quantitative real-time PCR.

Results

CLE, especially at 50 µg/ml, showed potent inhibitory effects on T. gondii tachyzoites. It increased the survival rate (ninth day) and reduced the mean number of peritoneal tachyzoites in the infected mice. CLE dependently increased (p < 0.01) the number of necrotic and apoptotic cells as well as NO production. CLE significantly (p < 0.05) reduced the hepatic level of oxidative stress markers but increased (p < 0.001) the antioxidant enzymes and proinflammatory cytokines in the infected mice, with no important toxicity for vital organs.

Conclusion

The findings of this survey revealed the significant in vitro inhibitory effects of CLE on T. gondii tachyzoites. The results also exhibited promising in vivo effects of CLE. CLE improved the survival rate of infected mice and reduced the parasite number in them. Although the mechanisms of action of CLE are not clear, our study demonstrated its beneficial effects on acute toxoplasmosis by strengthening the immune system and reducing inflammation and oxidative stress. Still, more studies are required to confirm these results.

The imbalance in the relationship between inflammatory and regulatory cytokines during gestational toxoplasmosis can be harmful to fetuses: A systematic review

Objective

To evaluate the available information on inflammatory and regulatory plasma mediators in pregnant women (PW) diagnosed with toxoplasmosis. Source: The PubMed, Embase, Scopus, and Lilacs databases were evaluated until October 2022. Study eligibility criteria: This review was carried out following the PRISMA and registered on the PROSPERO platform (CRD42020203951). Studies that reported inflammatory mediators in PW with toxoplasmosis were considered.

Evaluation methods

After excluding duplicate articles, two authors independently carried out the process of title and abstract exclusion, and a third resolved disagreements when necessary. The full text was evaluated to detect related articles. The extraction table was built from the following data: Author, year of publication, journal name and impact factors, country, study design, number of gestations and maternal age (years), gestational period, diagnosis of toxoplasmosis, levels of inflammatory markers, laboratory tests, and clinical significance. Methodological quality was assessed using Joanna Briggs Institute tools.

Results

Of the 1,024 studies reported, only eight were included. Of the 868 PW included in this review, 20.2% were IgM+/IgG- and 50.8% were IgM-/IgG+ to T. gondii, and 29.0% uninfected. Infected PW presented higher plasma levels ofIL-5, IL-6, IL-8, IL-17, CCL5, and IL-10. Regarding the methodological quality, four studies obtained high quality. Data from this review pointed out the maintenance of the inflammatory pattern during pregnancy with a closely related to the parasite.

Conclusion

Immune status in PW defined the course of the T. gondii infection, where the equilibrium between inflammatory and regulatory cytokines mitigated the harmful placenta and fetus effects.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier CRD420203951.

Treatments of Mycobacterium tuberculosis and Toxoplasma gondii with Selenium Nanoparticles

Toxoplasma gondii and Mycobacterium tuberculosis are pathogens that are harmful to humans. When these diseases interact in humans, the result is typically fatal to the public health. Several investigations on the relationship between M. tuberculosis and T. gondii infections have found that there is a strong correlation between them with each infection having a reciprocal effect on the other. TB may contribute to the reactivation of innate toxoplasmosis or enhance susceptibility to a new infection, and toxoplasma co-infection may worsen the severity of pulmonary tuberculosis. As a consequence, there is an earnest and urgent necessity to generate novel therapeutics that can subdue these challenges. Selenium nanostructures' compelling properties have been shown to be a successful treatment for Mycobacterium TB and Toxoplasma gondii. Despite the fact that selenium (Se) offers many health advantages for people, it also has a narrow therapeutic window; therefore, consuming too much of either inorganic or organic compounds based on selenium can be hazardous. Compared to both inorganic and organic Se, Se nanoparticles (SeNPs) are less hazardous. They are biocompatible and excellent in selectively targeting specific cells. As a consequence, this review conducted a summary of the efficacy of biogenic Se NPs in the treatment of tuberculosis (TB) and toxoplasmosis. Mycobacterium tuberculosis, Toxoplasma gondii, and their co-infection were all briefly described.

Inhibition of Toxoplasma gondii by 1,2,4-triazole-based compounds: marked improvement in selectivity relative to the standard therapy pyrimethamine and sulfadiazine

A safer treatment for toxoplasmosis would be achieved by improving the selectivity profile of novel chemotherapeutics compared to the standard therapy pyrimethamine (PYR) and sulfadiazine (SDZ). We previously reported on the identification of the compounds with imidazole-thiosemicarbazide scaffold as potent and selective anti-Toxoplasma gondii (T. gondii) agents. In our current research, we report on the optimisation of this chemical scaffold leading to the discovery cyclic analogue 20 b with s-triazole core structure. This compound displayed prominent CC₃₀ to IC₅₀ selectivity index (SI) of 70.72, making it 160-fold more selective than SDZ, 11-fold more selective than PYR, and 4-fold more selective than trimethoprim (TRI). Additionally, this compound possesses prerequisite drug-like anti-Toxoplasma properties to advance into preclinical development; it showed ability to cross the BBB, did not induce genotoxic and haemolytic changes in human cells, and as well as it was characterised by low cellular toxicity.

Prevalence of Toxoplasma gondii infection in animals of the Arabian Peninsula between 2000-2020: A systematic review and meta-analysis

BACKGROUND

Toxoplasma gondii (T. gondii) is a zoonotic parasite that can be transmitted from animals to humans, with felids acting as its definitive host. Thus, understanding the epidemiology of this parasite in animal populations is vital to controlling its transmission to humans as well as to other animal groups.

OBJECTIVES

This systematic review and meta-analysis aims to summarise and analyse reports of T. gondii infection in animal species residing in the Arabian Peninsula.

METHODS

It was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), with relevant studies being retrieved from MEDLINE/PubMed, Scopus, Cochrane Library, Google Scholar and ScienceDirect. All articles published in Arabic or English languages between January 2000 and December 2020 were screened for eligibility. Random effects model was used to calculate the pooled prevalence of T. gondii infection in different animal populations which were found to harbour this infection. The critical appraisal tool for prevalence studies designed by the Joanna Briggs Institute (JBI) was used to assess the risk of bias in all included studies.

RESULTS

A total of 15 studies were retrieved, reporting prevalence estimates from 4 countries in this region and in 13 animal species. Quantitative meta-analysis estimated a pooled prevalence of 43% in felids [95% confidence interval (CI) = 23-64%, I² index = 100%], 48% in sheep (95% CI = 27-70%, I² = 99%) and 21% in camels (95% CI = 7-35%, I² = 99%). Evidence of possible publication bias was found in both felids and sheep.

CONCLUSIONS

This meta-analysis estimates a high prevalence of T. gondii infection in animal species which are of high economic and cultural importance to countries of this region. Hence, these findings provide valuable insight to public health authorities as well as economic and animal resources advisors in countries of the Arabian Peninsula.

Diffuse Large B-Cell Epstein-Barr Virus-Positive Primary CNS Lymphoma in Non-AIDS Patients: High Diagnostic Accuracy of DSC Perfusion Metrics

BACKGROUND AND PURPOSE

Immunodeficiency-associated CNS lymphoma may occur in different clinical scenarios beyond AIDS. This subtype of CNS lymphoma is diffuse large B-cell and Epstein-Barr virus-positive. Its accurate presurgical diagnosis is often unfeasible because it appears as ring-enhancing lesions mimicking glioblastoma or metastasis. In this article, we describe clinicoradiologic features and test the performance of DSC-PWI metrics for presurgical identification.

MATERIALS AND METHODS

Patients without AIDS with histologically confirmed diffuse large B-cell Epstein-Barr virus-positive primary CNS lymphoma (December 2010 to January 2022) and diagnostic MR imaging without onco-specific treatment were retrospectively studied. Clinical, demographic, and conventional imaging data were reviewed. Previously published DSC-PWI time-intensity curve analysis methodology, to presurgically identify primary CNS lymphoma, was used in this particular lymphoma subtype and compared with a prior cohort of 33 patients with Epstein-Barr virus-negative CNS lymphoma, 35 with glioblastoma, and 36 with metastasis data. Normalized curves were analyzed and compared on a point-by-point basis, and previously published classifiers were tested. The standard percentage of signal recovery and CBV values were also evaluated.

RESULTS

Seven patients with Epstein-Barr virus-positive primary CNS lymphoma were included in the study. DSC-PWI normalized time-intensity curve analysis performed the best for presurgical identification of Epstein-Barr virus-positive CNS lymphoma (area under the receiver operating characteristic curve of 0.984 for glioblastoma and 0.898 for metastasis), followed by the percentage of signal recovery (0.833 and 0.873) and CBV (0.855 and 0.687).

CONCLUSIONS

When a necrotic tumor is found in a potentially immunocompromised host, neuroradiologists should consider Epstein-Barr virus-positive CNS lymphoma. DSC-PWI could be very useful for presurgical characterization, with especially strong performance of normalized time-intensity curves.

Toxoplasma gondii Infection in Immunocompromised Patients in Iran (2013-2022): A Systematic Review and Meta-Analysis

Background

Toxoplasma gondii infection (toxoplasmosis) has the potential to cause a serious disease in immunocompromised patients and can be fatal in this population. We conducted a systematic review and meta-analysis to assess comprehensively the pooled seroprevalence of toxoplasmosis among immunocompromised patients including HIV/AIDS patients, cancer patients, and transplant recipients in Iran.

Methods

PubMed, Web of Science, Scopus, Embase, and Google Scholar databases (international) and Scientific Information Database (SID), Magiran, IranMedex, and IranDoc databases (national) were systematically searched for all reports that possibly contained data for T. gondii prevalence in different immunocompromised populations in Iran between 2013 and 2022.

Results

Overall, IgG seroprevalence rate of toxoplasmosis in Iranian immunocompromised patients was 45.1% (95% confidence interval (CI), 37.4-52.9). IgG seroprevalence rate of toxoplasmosis in 12 studies that included 2279 cancer patients, 19 studies that included 2565 HIV/AIDS patients and in 3 studies that included 200 transplant recipients was 43.6% (95% CI, 30.2-57.0), 45.9% (95% CI, 34.8-57.1) and 45.8% (95% CI, 32.5-59.0), respectively. Moreover, IgM seroprevalence rate in the 26 studies was 2.6% (95% CI, 1.4-3.7).

Conclusion

Our findings represent a high seroprevalence rate of Toxoplasma IgG among immunocompromised patients. Health improvement and education toward prevention of toxoplasmosis is of great importance for these susceptible populations.

Designing a Multi-Epitope Vaccine against Toxoplasma gondii: An Immunoinformatics Approach

Infection with the intracellular apicomplexan parasite Toxoplasma gondii causes serious clinical outcomes in both human and veterinary settings worldwide. Although approximately one-third of the world’s population is infected with T. gondii, an effective human vaccine for this disease remains unavailable. We aimed to design a potential T. gondii vaccine candidate that consisted of the B- and T-lymphocyte epitopes of three parasite immunogenic antigens. Firstly, the immunodominant epitopes expressed within the ROP2, MIC3, and GRA7 proteins of T. gondii were identified. Subsequently, six B-cell epitopes, five CTL epitopes, and five HTL epitopes were combined to generate a multi-epitope vaccine, and the 50S ribosomal protein L7/L12 was added as an adjuvant to boost the vaccine’s immunogenicity. All these epitopes were found to be antigenic, nonallergenic, nontoxic, and nonhuman homologs. The designed vaccine construct has a molecular weight of 51 kDa, an antigenicity score of 0.6182, and a solubility of 0.903461. Likewise, the candidate vaccine was immunogenic, nonallergenic, and stable. Molecular docking analysis revealed stable interactions between the vaccine construct and the TLR-4 immune receptor. Meanwhile, the stability of the developed vaccine was validated using molecular dynamics simulation. In silico, the vaccine construct was able to trigger primary immune responses. However, further laboratory-based assessments are needed to confirm its efficacy and safety.

Ceramide biosynthesis is critical for establishment of the intracellular niche of Toxoplasma gondii

Toxoplasma gondii possesses sphingolipid synthesis capabilities and is equipped to salvage lipids from its host. The contribution of these two routes of lipid acquisition during parasite development is unclear. As part of a complete ceramide synthesis pathway, T. gondii expresses two serine palmitoyltransferases (TgSPT1 and TgSPT2) and a dihydroceramide desaturase. After deletion of these genes, we determine their role in parasite development in vitro and in vivo during acute and chronic infection. Detailed phenotyping through lipidomic approaches reveal a perturbed sphingolipidome in these mutants, characterized by a drastic reduction in ceramides and ceramide phosphoethanolamines but not sphingomyelins. Critically, parasites lacking TgSPT1 display decreased fitness, marked by reduced growth rates and a selective defect in rhoptry discharge in the form of secretory vesicles, causing an invasion defect. Disruption of de novo ceramide synthesis modestly affects acute infection in vivo but severely reduces cyst burden in the brain of chronically infected mice.

IgG Avidity Test as a Tool for Discrimination between Recent and Distant Toxoplasma gondii Infection—Current Status of Studies

Toxoplasma gondii, an obligate intracellular protozoan parasite, is the causative agent of one of the most prevalent zoonoses worldwide. T. gondii infection is extremely important from a medical point of view, especially for pregnant women, newborns with congenital infections, and immunocompromised individuals. Thus, an accurate and proper diagnosis of this infection is essential. Among the available diagnostic tests, serology is commonly used. However, traditional serological techniques have certain limitations in evaluating the duration of T. gondii infection, which is problematic, especially for pregnant women. Avidity of T. gondii-specific IgG antibodies seems to be a significant tool for discrimination between recent and distant infections. This article describes the problem of diagnosis of T. gondii infection, with regard to IgG avidity tests. The IgG avidity test is a useful serological indicator of toxoplasmosis, which in many cases can confirm or exclude the active form of the disease. IgG antibodies produced in the recent primary T. gondii infection are of low avidity while IgG antibodies with high avidity are detected in the chronic phase of infection. Furthermore, this paper presents important topics of current research that concern the usage of parasite recombinant antigens that may improve the performance of IgG avidity tests.

Serological survey of Toxoplasma gondii infection in cats in Khon Kaen, Northeast Thailand

Background and Aim: Toxoplasmosis is a zoonosis caused by Toxoplasma gondii. Cats are known to be the definitive hosts that can excrete these environmentally resistant oocysts. Other mammals, avians, and even humans can serve as the intermediate host. T. gondii infection is often asymptomatic in healthy individuals; however, it could result in serious health problems in immunocompromised and pregnant individuals. This study investigated the occurrence of T. gondii infection in cats in Khao Suan Kwang and Mueang Khon Kaen. Materials and Methods: In total, 100 serum samples from cats, that is, 62 owned cats (31 males and 31 females) and 38 adopted stray cats (21 males and 17 females), were examined for antibodies against T. gondii through rapid immunochromatographic tests (ICT). Owners were asked to sign a consent form and answer the questionnaires before sample collection. Demographic information about the cats and their owners was also recorded. Results: The overall seroprevalence of cats positive for T. gondii antibodies was found to be 5%. Notably, the Toxoplasma antibody prevalence was significantly higher in the adopted stray cats (10.53% [4/38]) that roamed the zoo than in the owned cats (1.61% [1/62]) (p > 0.05). No significant difference was observed between male (8.33%) and female (1.92%) cats. The cat owners' questionnaire revealed that more than half had never heard of toxoplasmosis before (67.7%), whereas 30.6% knew nothing about the disease transmission routes. Conclusion: This study presented a low seroprevalence of antibodies to T. gondii in owned cats from the Mueang Khon Kaen District, whereas high seroprevalence was detected in the adopted stray cats from Khao Suan Kwang. Adopted stray cats can have a higher potential for T. gondii infection; thus, they could be a source of toxoplasmosis transmission to humans. Therefore, it is essential to control the number of stray cats, and a screening test for antitoxoplasmosis could be recommended before adoption. Although the total seroprevalence was noted to be low, the zoonotic disease was present. Therefore, raising the community's awareness and knowledge might reduce the disease transmission from animals to humans.

Ginger Is a Potential Therapeutic for Chronic Toxoplasmosis

Background:Toxoplasma gondii (T. gondii) is an opportunistic parasite that causes serious diseases in humans, particularly immunocompromised individuals and pregnant women. To date, there are limited numbers of therapeutics for chronic toxoplasmosis which necessitate the discovery of effective and safe therapeutics. In the present study, we aimed to evaluate the antitoxoplasmosis potential of ginger extract in mice with experimentally induced chronic toxoplasmosis. Results: Treatment with ginger extract significantly reduced cysts count in the brains of T. gondii-infected mice with a marked alleviation of edema and inflammation, and a reversal of neuronal injury. Moreover, ginger extract treatment reduced inflammation in liver and lungs and protected hepatocytes from infection-induced degeneration. Consistently, apoptosis was significantly mitigated in the brains of ginger extract-treated mice compared to infected untreated animals or spiramycin-treated animals. Methods: Four groups of Swiss albino mice (10 mice each) were used. The first group was not infected, whereas 3 groups were infected with Me49 T. gondii strains. One infected group remained untreated (infected untreated), whereas the other two infected groups were treated with either ginger extract (250 mg/kg) or spiramycin (positive control; 100 mg/kg), respectively. The therapeutic potential of ginger extract was evaluated by calculation of the parasite burden in infected animals, and examination of the infected tissues for reduced pathologic changes. Conclusions: Our results showed for the first time that ginger extract exhibited marked therapeutic effects in mice with chronic T. gondii infection which indicates that it can be used as a safe and effective treatment for chronic toxoplasmosis.

Therapeutic Potential and Safety of the Cinnamomum zeylanicum Methanolic Extract Against Chronic Toxoplasma gondii Infection in Mice

Background

This experimental study determined the in vitro, in vivo, and toxicity effects of Cinnamomum zeylanicum methanolic extract (CZME) against Toxoplasma gondii infection.

Methods

The in vitro activity of CZME T. gondii tachyzoites was studied by the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. Infected mice were treated with CZME for two weeks at doses of 20, 40, and 60 mg/kg/day. Then, the therapeutic effects of CZME were evaluated by assessing the mean number and mean size of T. gondii tissue cysts, oxidant-antioxidant enzymes, pro-inflammatory cytokines, and mRNA expression levels of bradyzoite surface antigen 1 (BAG1) by real-time PCR.

Results

CZME significantly (p <0.001) increased the mortality rate of parasites in a dose- and time-dependent response. The mean number of intracellular tachyzoites was significantly reduced after CZME therapy. The treatment of infected mice with CZME resulted in a significant (p <0.001) downregulation of BAG1 and the level of lipid peroxidation (LPO) and nitric oxide (NO) as oxidative stress markers. However, a considerable rise (p <0.05) was found in the levels of antioxidant markers such as glutathione peroxidase (GPx), catalase enzyme (CAT), and superoxide dismutase enzyme activity (SOD). In a dose-dependent response, after treatment of infected mice with CZME, the level of pro-inflammatory cytokines of IFN-γ, IL-1β, and IL-12 was considerably elevated. CZME had no significant cytotoxicity on Vero cells, with a 50% cytotoxic concentration of 169.5 ± 5.66 μg/ml.

Conclusion

The findings confirmed the promising therapeutic effects of CZME on chronic toxoplasmosis in mice. Nevertheless, further investigations must confirm these results, elucidate its precise mechanisms, and examine its effectiveness in human volunteers.

Tamoxifen Increased Parasite Burden and Induced a Series of Histopathological and Immunohistochemical Changes During Chronic Toxoplasmosis in Experimentally Infected Mice

The global distribution of breast cancer and the opportunistic nature of the parasite have resulted in many patients with breast cancer becoming infected with toxoplasmosis. However, very limited information is available about the potential effects of tamoxifen on chronic toxoplasmosis and its contribution to the reactivation of the latent infection. The present study investigated the potential effects of tamoxifen on chronic toxoplasmosis in animal models (Swiss albino mice). Following induction of chronic toxoplasmosis and treatment with the drug for 14 and 28 days, the anti-parasitic effects of tamoxifen were evaluated by parasitological assessment and counting of Toxoplasma cysts. In addition, the effects of the drug on the parasite load were evaluated and quantitated using TaqMan real-time quantitative PCR followed by investigation of the major histopathological changes and immunohistochemical findings. Interestingly, tamoxifen increased the parasite burden on animals treated with the drug during 14 and 28 days as compared with the control group. The quantification of the DNA concentrations of Toxoplasma P29 gene after the treatment with the drug revealed a higher parasite load in both treated groups vs. control groups. Furthermore, treatment with tamoxifen induced a series of histopathological and immunohistochemical changes in the kidney, liver, brain, and uterus, revealing the exacerbating effect of tamoxifen against chronic toxoplasmosis. These changes were represented by the presence of multiple T. gondii tissue cysts in the lumen of proximal convoluted tubules associated with complete necrosis in their lining epithelium of the kidney section. Meanwhile, liver tissue revealed multiple T. gondii tissue cysts in hepatic parenchyma which altered the structure of hepatocytes. Moreover, clusters of intracellular tachyzoites were observed in the lining epithelium of endometrium associated with severe endometrial necrosis and appeared as diffuse nuclear pyknosis combined with sever mononuclear cellular infiltration. Brain tissues experienced the presence of hemorrhages in pia mater and multiple T. gondii tissue cysts in brain tissue. The severity of the lesions was maximized by increasing the duration of treatment. Collectively, the study concluded novel findings in relation to the potential role of tamoxifen during chronic toxoplasmosis. These findings are very important for combating the disease, particularly in immunocompromised patients which could be life-threatening.

Testosterone Augments Propagation of Toxoplasma gondii in Glioblastoma Cells In Vitro

PURPOSE

Toxoplasmosis can induce various hormonal and behavioral alterations in humans and rodents. Previous studies revealed alterations of sex hormones; especially testosterone, in infected humans and rodents, but little is known about the effects of sex hormones on the propagation of T. gondii. Hence, we aimed to investigate whether testosterone and progesterone influence on T. gondii propagation in neural cells.

METHODS

The glioblastoma cells (U-87MG) were treated with different concentrations of testosterone and progesterone and the infection was done by tachyzoites of the RH strain of T. gondii. The number of infected cells, viability of T. gondii-infected cells, and parasite burden were measured by direct counting under a light microscope, MTT assay, and quantitative real-time PCR (qPCR), respectively.

RESULTS

The results showed that testosterone at concentrations of 100 and 250 nM significantly increased the number of infected cells and parasite burden 24 and 48 h post-treatment compared to untreated controls. Progesterone had no significant effects in the same manner.

CONCLUSION

The results indicated that testosterone could augment the propagation of T. gondii in in vitro.

Nano vaccines for T. gondii Ribosomal P2 Protein With Nanomaterials as a Promising DNA Vaccine Against Toxoplasmosis

Caused by Toxoplasma gondii, toxoplasmosis has aroused great threats to public health around the world. So far, no effective vaccine or drug is commercially available, and the demands for a safe and effective therapeutic strategy have become more and more urgent. In the current study, we constructed a DNA vaccine encoding T. gondii ribosomal P2 protein (TgP2) and denoted as TgP2-pVAX1 plasmid. To improve the immunoprotection, nanomaterial poly-lactic-co-glycolic acid (PLGA) and chitosan were used as the delivery vehicle to construct TgP2-pVAX1/PLGA and TgP2-pVAX1/CS nanospheres. Before vaccinations in BALB/c mice, TgP2-pVAX1 plasmids were transiently transfected into Human Embryonic Kidney (HEK) 293-T cells, and the expression of the eukaryotic plasmids was detected by laser confocal microscopy and Western blotting. Then the immunoprotection of naked DNA plasmids and their two nano-encapsulations were evaluated in the laboratory animal model. According to the investigations of antibody, cytokine, dendritic cell (DC) maturation, molecule expression, splenocyte proliferation, and T lymphocyte proportion, TgP2-pVAX1 plasmid delivered by two types of nanospheres could elicit a mixed Th1/Th2 immune response and Th1 immunity as the dominant. In addition, TgP2-pVAX1/PLGA and TgP2-pVAX1/CS nanospheres have great advantages in enhancing immunity against a lethal dose of T. gondii RH strain challenge. All these results suggested that TgP2-pVAX1 plasmids delivered by PLGA or chitosan nanomaterial could be promising vaccines in resisting toxoplasmosis and deserve further investigations and applications.

Mining the Proteome of Toxoplasma Parasites Seeking Vaccine and Diagnostic Candidates

Simple Summary

The One Health concept to toxoplasmosis highlights that the health of humans is closely related to the health of animals and our common environment. Toxoplasmosis outcomes might be severe and fatal in patients with immunodeficiency, diabetes, and pregnant women and infants. Consequently, the development of effective vaccine and diagnostic strategies is urgent for the elimination of this disease. Proteomics analysis has allowed the identification of key proteins that can be utilized in the development of novel disease diagnostics and vaccines. This work presents relevant proteins found in the proteome of the life cycle-specific stages of Toxoplasma parasites. In fact, it brings together the main functionality key proteins from Toxoplasma parasites coming from proteomic approaches that are most likely to be useful in improving the disease management, and critically proposes innovative directions to finally develop promising vaccines and diagnostics tools.

Abstract

Toxoplasma gondii is a pathogenic protozoan parasite that infects the nucleated cells of warm-blooded hosts leading to an infectious zoonotic disease known as toxoplasmosis. The infection outcomes might be severe and fatal in patients with immunodeficiency, diabetes, and pregnant women and infants. The One Health approach to toxoplasmosis highlights that the health of humans is closely related to the health of animals and our common environment. The presence of drug resistance and side effects, the further improvement of sensitivity and specificity of serodiagnostic tools and the potentiality of vaccine candidates to induce the host immune response are considered as justifiable reasons for the identification of novel targets for the better management of toxoplasmosis. Thus, the identification of new critical proteins in the proteome of Toxoplasma parasites can also be helpful in designing and test more effective drugs, vaccines, and diagnostic tools. Accordingly, in this study we present important proteins found in the proteome of the life cycle-specific stages of Toxoplasma parasites that are potential diagnostic or vaccine candidates. The current study might help to understand the complexity of these parasites and provide a possible source of strategies and biomolecules that can be further evaluated in the pathobiology of Toxoplasma parasites and for diagnostics and vaccine trials against this disease.

Misdiagnosis of HIV With Toxoplasmosis Encephalopathy With Progressive Memory Loss as the Initial Symptom: A Case Report

Toxoplasmosis encephalopathy (TE) is a kind of encephalopathy parasitic disease caused by Toxoplasma gondii. It is the most common opportunistic for central system infection in patients with acquired immunodeficiency syndrome (AIDS) or human immunodeficiency virus. Without early diagnosis and proper treatment, this opportunistic infection can be life-threatening. The common clinical manifestations of the disease include altered mental state, epilepsy, cranial nerve damage, paresthesia, cerebellar signs, meningitis, motor disorders, and neuropsychiatry. The most common presentation in about 75% of cases is a subacute episode of focal neurological abnormalities such as hemiplegia, personality changes, or aphasia. Imaging needs to be differentiated from multiple sclerosis, lymphoma, and metastases. We report a case of acquired immune deficiency syndrome complicated with toxoplasma encephalopathy with rapid progressive memory loss as the initial symptom and misdiagnosed as multiple sclerosis. Through the comprehensive analysis of the clinical symptoms and imaging examination of this disease, we hope to enhance the confidence of clinicians in the diagnosis of this disease.

A Meta-Analysis of the Prevalence of Toxoplasmosis in Livestock and Poultry Worldwide

Toxoplasma gondii causes toxoplasmosis with a global prevalence in the world. A large proportion of human illness is most frequently associated with consuming raw and undercooked meat or other animal products containing infective parasitic stages of T. gondii. This systematic review and meta-analysis study evaluated the prevalence of toxoplasmosis in cattle, sheep, camels, goats, and poultry worldwide. The search was performed in databases including PubMed, WoS, Scopus, Science Direct, Google Scholar, and ISC from 2000 to 2019 in Persian and English. The main inclusion criteria were the prevalence of toxoplasmosis among livestock and poultry and the prevalence indices by sample size. During these 20 years, the overall prevalence of toxoplasmosis in livestock and poultry was 28.3% (95% confidence interval (CI) 25-31.9%) using the random-effects meta-analysis model. The highest prevalence of T. gondii in livestock and poultry animals was found in Asia in 2014 with 89.8% (95% CI 78.5-95.5%). The lowest prevalence was found in Asia in 2013 with 1.26% (95% CI 0.4-3.8%). A quarter of livestock and poultry were infected with T. gondii. Since livestock products are globally important sources of people's diet, our findings are useful for policymakers to control T. gondii infection in livestock.

Pantothenate biosynthesis is critical for chronic infection by the neurotropic parasite Toxoplasma gondii

Coenzyme A (CoA) is an essential molecule acting in metabolism, post-translational modification, and regulation of gene expression. While all organisms synthesize CoA, many, including humans, are unable to produce its precursor, pantothenate. Intriguingly, like most plants, fungi and bacteria, parasites of the coccidian subgroup of Apicomplexa, including the human pathogen Toxoplasma gondii, possess all the enzymes required for de novo synthesis of pantothenate. Here, the importance of CoA and pantothenate biosynthesis for the acute and chronic stages of T. gondii infection is dissected through genetic, biochemical and metabolomic approaches, revealing that CoA synthesis is essential for T. gondii tachyzoites, due to the parasite's inability to salvage CoA or intermediates of the pathway. In contrast, pantothenate synthesis is only partially active in T. gondii tachyzoites, making the parasite reliant on its uptake. However, pantothenate synthesis is crucial for the establishment of chronic infection, offering a promising target for intervention against the persistent stage of T. gondii.

Dynamics of natural infection by Toxoplasma gondii in goat herds in the semiarid region of northeastern Brazil: transitional antibody observation

This study aimed to describe the transmission of T. gondii in naturally infected goats in the semiarid region of northeastern Brazil, through evaluating the serological status of these animals from one to 12 months of age. Seven goat farms were selected. During the first visit, an epidemiological questionnaire was applied. Blood samples were collected from pregnant goats and from their female offspring every month, to monitor them for anti-T. gondii antibodies, using the indirect fluorescence antibody test (IFAT). Out of 66 pregnant goats evaluated, 47% (31/66) (95% CI: 34.6% - 59.7%) were positive and out of 93 female offspring, 61.3% (57/93) (95% CI: 52.4% - 69.2%) were positive, in at least one month during the evaluation period. Among the positive female offspring, 43.3% (27/57) (95% CI: 39.7% - 56.9%) presented environmental infection and 56.7% (30/57) (95% CI: 43.4% - 66.3 %) probably had only colostral antibodies or vertical transmission. It was observed that 92,6% (25/27) from environmental infections occurred until reproductive age (six months) (p<0.0001). It was also noted that there is a correlation between the titration of mothers and offspring, until four months of age (p<0.0001). Large fluctuations in the presence of antibodies were observed among the animals over the months monitored. It can be concluded that the prevalence of anti-T. gondii antibodies within the herds was greater than what has been expressed in specific prevalence studies and that most goat become infected up to the six months of life in the studied area.

An evaluation of the level of testosterone, DHEA and prolactin among Toxoplasma gondii infected and uninfected infertile couples attending to Fatima Al-Zahra infertility treatment center, Babol, Northern Iran

Introduction/Aims: Toxoplasmosis modifies various hormones and cytokines in the infected hosts which may result in several disorders. This study was conducted to assess testosterone, DHEA, and prolactin concentration levels among Toxoplasma gondii infected and uninfected infertile couples. Methods: Blood samples were collected and sera were separated. The sera were analyzed for the detection of anti-Toxoplasma (IgG& IgM) antibodies using commercial ELISA kits. The level of DHEA was measured by ELISA and the levels of testosterone and prolactin were evaluated by enzyme-linked fluorescent assay (ELFA, VIDAS). Results: The overall seroprevalence of toxoplasmosis was 58.0% (218/376). Among women, 56.9% (107/188) and 6.5% (7/107) were positive for anti-T. gondii antibodies IgG and IgM, respectively. The IgG and IgM were detected in the sera of 111/188 (59.0%) and 9/111 (8.1%) in male subjects, respectively. A positive association was observed between T. gondii infection and the upper and lower ranges of the normal value of testosterone in males (x 2 = 6.8, p = 0.033) but not in females (x 2 = 0.62, p = 0.99). A positive correlation was seen between toxoplasmosis and the upper and lower ranges of the normal value of prolactin in females (x 2 = 6.5, p = 0.039) but not in male cases (x 2 = 1.06, p = 0.59). Conclusion: Our results demonstrated no statistically significant differences between the level of sexual hormones between Toxoplasma-infected individuals and Toxoplasma-free subjects suffering from infertility. These findings suggest that further studies should be performed on infertile cases with large sample sizes in a case-control format.

Disseminated Toxoplasma gondii Infection in an Adult Osprey (Pandion haliaetus)

An adult female osprey (Pandion haliaetus) was found weak and unable to fly in Auburn, Alabama in August 2019. The bird was captured and submitted to the Southeastern Raptor Center of the Auburn University College of Veterinary Medicine for evaluation. On presentation, the bird was thin with a body condition score of approximately 1.5 out of 5. The bird died during the examination and was submitted for necropsy. At the necropsy, there was a severe loss of muscle mass over the body, and the keel was prominent. The liver and spleen were moderately enlarged with pale tan to red foci randomly scattered throughout the parenchyma. A histopathologic observation revealed multifocal to coalescing areas of necrosis and hemorrhage with intralesional protozoans in the liver, spleen, lungs, kidney, sciatic nerve, esophagus, cerebrum, heart, and proventriculus. Immunohistochemistry using anti-Toxoplasma gondii-specific antibodies showed a strong positive labeling of the parasite. Semi-nested PCR, specific for the B1 gene of T. gondii, successfully identified T. gondii. This is the first confirmed case of T. gondii infection in an osprey.

In vitro and in vivo Anti-Toxoplasma Effects of Allium sativum Essential Oil Against Toxoplasma gondii RH Strain

Background

Since no effective vaccine has been developed for toxoplasmosis, prophylaxis in seronegative pregnant women and immunocompromised patients with a CD4 <100 cells/μL is highly recommended as an ideal strategy to prevent this disease. This study aimed to assess the chemical composition, in vitro, and in vivo effects of Allium sativum essential oil (ASEO) against Toxoplasma gondii RH strain.

Methods

The in vitro anti-Toxoplasma effects of different concentrations of ASEO (32.5, 75, 150 µg/mL) were measured by MTT assay for 0.5, 1, 2, and 3 h. Male Balb/c mice were orally administrated ASEO at the doses of 200, 400, and 600 µg/kg/day for 14 days. One day after the completion of oral drug administration, the mice in all groups were infected intraperitoneally with 1×10⁴ tachyzoites. They were checked daily and the rate of survival was recorded. The peritoneal fluids of the mice were collected and the mean number of tachyzoites was calculated via a light microscope. The level of liver lipid peroxidation (LPO) and nitric oxide (NO), toxicity effects on the liver and kidney, and the mRNA expression levels of some pro-inflammatory cytokines such as IL-1β and IFN-γ were determined by quantitative real-time PCR.

Results

Different concentrations of ASEO showed a significant (p < 0.001) anti-Toxoplasma activity against T. gondii tachyzoites, and the highest efficacy was observed at the concentration of 150 µg/mL. Fourteen days of pre-treatment of infected mice with ASEO at the doses of 200, 400, and 600 µg/kg/day significantly (p < 0.001) decreased the mean number of tachyzoites and mortality rate by the 6th, 7th, and 8th days after infection, respectively. ASEO at the doses of 200, 400, and 600 µg/kg/day significantly (p < 0.05) improved the increase in the LPO and NO. Pre-treatment of mice with different doses of ASEO provoked a considerable (P < 0.001) downregulation of IL-1β and IFN-γ mRNA gene expression levels, but it had no significant toxicity on the serum levels of some liver and kidney enzymes.

Conclusion

The present study demonstrated the considerable prophylactic effects of ASEO that increased the survival rate of mice and reduced the parasite load in them. Our findings also showed that ASEO promotes the innate immune system, pro-inflammatory cytokines, inhibition of hepatic injury, etc. in the mice with acute toxoplasmosis. However, additional investigations are mandatory to clarify the accurate prophylactic and therapeutic anti-Toxoplasma mechanisms of ASEO as well as all its toxicity aspects, especially in clinical settings.