Toxoplasma gondii: from animals to humans

Toxoplasma gondii genotypes and frequency in domestic cats from Romania

BACKGROUND

Toxoplasma gondii is a zoonotic protozoan parasite with a heteroxenus life cycle that involves felids as the definitive hosts and any warm-blooded animal, including humans, as intermediate hosts. Cats are key players in parasite transmission as they are capable of shedding high numbers of oocysts in their feces that contaminate the environment.

METHODS

The study was performed on 31 domestic cats (31.23 ± 27.18 months old) originating from rural and urban areas (5.17:1) in the center and north-west Romania. Feces (n = 31), blood (n = 28), and heart samples (n = 27) were collected. Fecal samples were analyzed by flotation technique, and PCR (529 bp repetitive element). Fecal samples with T. gondii oocysts were bioassayed in mice. Serum samples were analyzed by modified agglutination test and ImmunoComb for the detection of specific anti-T. gondii IgG antibodies. Heart samples were bioassayed in mice, and analyzed by PCR. Toxoplasma gondii positive samples were genotyped by nPCR-RFLP targeting eleven genetic loci (SAG1, SAG2, alt-SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and Apico).

RESULTS

Toxoplasma gondii oocysts were found in 2 out of 31 fecal samples collected from a 3-months old stray kitten, and a 4-years old female. In total, 17 out of 27 sera were positive for T. gondii IgG antibodies. The antibody titers in MAT ranged from 1:6 to 1:384. Toxoplasma gondii DNA was detected in 7 out of 27 heart samples, and four of them were positive also by bioassay. Six T. gondii DNA samples from bioassayed mice could be assigned to ToxoDB PCR-RFLP genotype #1 or #3 (Type II) and one T. gondii DNA from heart digest to genotype #2 (Type III). Both of these genotypes are common in Europe.

CONCLUSIONS

Our results revealed that the infection with T. gondii is still high in cats from Romania. The oocysts shedded by these cats represent an important source of infection for intermediate hosts, including humans. Further studies on a wider range of cases are necessary for a more exhaustive definition of the T. gondii genotypes circulating in Romania.

PruΔcdpk2 Protects Pigs against Acute Toxoplasmosis Depending on T-Lymphocyte Subsets and Natural Killer Cell Responses

Toxoplasma gondii is a widespread protozoan parasite approximately infecting one-third of the world population and can cause serious public health problems. In this study, we investigated the protective effect of the attenuated vaccine Pru:Δcdpk2 against acute toxoplasmosis and explored the underlying immune mechanisms of the protection in pigs. The systemic T-cell and natural killer (NK) cell responses were analyzed, including kinetics, phenotype, and multifunctionality (interferon [IFN]-γ, tumor necrosis factor [TNF]-α), and the IFN-γ levels were analyzed in PBMCs. Our results showed that T. gondii-specific antibodies were induced by Pru:Δcdpk2. After challenging with RH, the antibodies were able to respond quickly in the immunized group, and the expression level was significantly higher than that in the unimmunized group. The expression level of IFN-γ significantly increased after vaccination, and the CD3+ γδ-, NK, and CD3+ γδ+ cell subsets also significantly increased. At the same time, functional analysis indicated that these cells were polarized toward a Th1 phenotype, showing the ability to secrete IFN-γ and TNF-α. The CD4+CD8α-T cell population exhibited a higher frequency of IFN-γ+ producing cells compared with the CD4-CD8α+ and CD4+CD8α+ cell populations during the early days of vaccination. Our results indicated that the attenuated vaccine could induce the expression of NK, γδ, and CD3αβ cells in pigs, and IFN-γ and TNF-α secreted by these cells are important for resistance to T. gondii infection.

Serological evidence of exposition to Toxoplasma gondii in Saimiri spp. kept in a research institution as biomodels in Rio de Janeiro

Anti-Toxoplasma gondii antibodies were investigated in 125 Saimiri spp. kept at a research institute. A total of 12% of primates tested positive, all of which were Saimiri sciureus. These results highlight the need to minimize the possibility of this protozoan's circulation, which can lead to fulminant infection in these animals.

Parasitological examination results of zoo animals in Germany between 2012 and 2022

Parasitic infections in zoo animals are a critical concern for both animal health and management. The aim of this study was to assess the occurrence of endo- and ectoparasites among zoo animals in Germany. A retrospective analysis of the submitted samples of a diverse range of zoo animals (5768) from a ten-year period (2012-2022) was conducted. Overall, 31.1% of those samples tested positive for at least one parasite. In the examined samples, helminths (28.4%) were found more often than protozoans (10.3%) or ectoparasites (0.8%). Among the various animal groups the following parasites were found most commonly: Artiodactyla: Coccidia (34.6%), Strongylida (23.4%); Perissodactyla: Strongylida (19.3%), Ascaridida (12.0%); Carnivora: Ascaridida (16.6%), Coccidia (8.1%); Rodentia: Oxyurida (18.2%), Coccidia (10.5%); Marsupialia: Coccidia (9.4%), Oxyurida (5.9%); Primates: Trichuris spp. (9.7%), Oxyurida (2.2%); Aves: Capillaria (7.8%), Ascaridida (7.6%); Reptilia, Amphibia, Insecta: Oxyurida (18.7%); Pisces: Ciliates (6.2%). Furthermore, potentially zoonotic parasites were identified, including Toxoplasma gondii (0.1%), Cryptosporidium sp. (0.1%). By examining the occurrence of specific parasites, these findings demonstrate the importance of parasites in the context of zoo animal health. They also highlight the need for effective strategies to control parasite burden to improve the overall welfare of zoo animals.

Toxoplasmic encephalitis with high 201Tl uptake and retention mimicking malignant lymphoma in a patient with human immunodeficiency virus infection

Various opportunistic infections develop during immunodeficiency due to human immunodeficiency virus (HIV) infection. The treatment options for malignant lymphoma (ML) and toxoplasmic encephalitis (TE) are completely different; therefore, their discrimination is critical. A 25-year-old female of foreign nationality had been experiencing headaches for several weeks and suddenly developed convulsions. Brain computed tomography revealed multiple intracranial lesions; therefore, the patient was referred to the neurosurgery department. Brain magnetic resonance imaging (MRI) revealed multiple masses with surrounding edema, accompanied by enhanced contrast. The largest mass (2 cm) in the left occipital lobe exhibited ringed contrast enhancement. Her blood test results showed a CD4 count of 40/μL, positive HIV Ag/Ab, HIV-RNA level of 56 × 104 copies/mL, positive anti-Toxoplasma IgG (63 IU/mL), and negative anti-Toxoplasma IgM. 201Tl- single photon emission computed tomography (201Tl-SPECT) revealed abnormal accumulation only in the tumor in the left occipital lobe (early T/N ratio, 3.034; delayed T/N ratio, 2.738; retention index, 0.9), which was suspected to be a ML. Both tumors, with or without high accumulation of 201Tl, were subjected to craniotomy biopsy. Pathological examination revealed infiltration of small lymphocytes with a necrotic background. The patient was diagnosed with TE based on a positive result of a tissue polymerase chain reaction test for Toxoplasma gondii. Two weeks after sulfamethoxazole and trimethoprim combination therapy, MRI imaging showed dramatic improvement in multiple brain tumors. This case is atypical because ML was ruled out despite high 201Tl-SPECT uptake and retention. Careful diagnosis through pathological examination and DNA testing is important.

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.

Combination of an enzyme-linked immunosorbent assay and an indirect fluorescence assay for a nationwide sero-survey of Toxoplasma gondii infection in pig herds in Taiwan

Toxoplasma gondii is a zoonotic pathogen that can infect farm animals, companion animals, and humans, sometimes causing public health issues. In Taiwan, the pig industry is a vital agricultural industry, with a self-sufficiency rate of 91 %, and pigs are also food-producing animal reservoirs of Toxoplasma gondii. Infected pigs are usually asymptomatic, and abortions and death may occur in severe cases. We combined an enzyme-linked immunosorbent assay (ELISA) and an indirect fluorescence assay (IFA) to investigate the seroprevalence of Toxoplasma gondii among pig populations in Taiwan. A stratified sampling approach to determine the number of sample farms proportional to the number of pig farms in each county was employed, with 15 blood samples collected at each farm between July and September 2017. With the tested results, empirical Bayesian smoothing was utilized to assess the proportion of Toxoplasma-positive farms at the county level. Bayesian mixed-effects logistic regression models, incorporating farm and county as random effects, were employed to investigate associations between Toxoplasma test results and potential risk factors. A total of 930 serum samples from 62 pig farms were collected and tested. An overall herd prevalence of 27.4 % was shown with the seroprevalence in northern Taiwan being greater than that in southern Taiwan. The sampling month and companion dog density in 2017 were significantly associated with Toxoplasma infections in pigs. With every increase in the number of companion dogs per km² at the county level, the odds of Toxoplasma infection in pigs increased by 4.7 % (95 % CI: 1.7-8.9 %). This study demonstrated that combining ELISA for screening with IFA for confirmation is a cost-effective and time-saving method for conducting a large-scale sample investigation. This was also the first nationwide, cross-sectional study in Taiwanese pig herds to investigate Toxoplasma gondii infection.

Two enzymes contribute to citrate production in the mitochondrion of Toxoplasma gondii

Citrate synthase catalyzes the first and the rate-limiting reaction of the tricarboxylic acid (TCA) cycle, producing citrate from the condensation of oxaloacetate and acetyl-coenzyme A. The parasitic protozoan Toxoplasma gondii has full TCA cycle activity, but its physiological roles remain poorly understood. In this study, we identified three proteins with predicted citrate synthase (CS) activities two of which were localized in the mitochondrion, including the 2-methylcitrate synthase (PrpC) that was thought to be involved in the 2-methylcitrate cycle, an alternative pathway for propionyl-CoA detoxification. Further analyses of the two mitochondrial enzymes showed that both had citrate synthase activity, but the catalytic efficiency of CS1 was much higher than that of PrpC. Consistently, the deletion of CS1 resulted in a significantly reduced flux of glucose-derived carbons into TCA cycle intermediates, leading to decreased parasite growth. In contrast, disruption of PrpC had little effect. On the other hand, simultaneous disruption of both CS1 and PrpC resulted in more severe metabolic changes and growth defects than a single deletion of either gene, suggesting that PrpC does contribute to citrate production under physiological conditions. Interestingly, deleting Δcs1 and Δprpc individually or in combination only mildly or negligibly affected the virulence of parasites in mice, suggesting that both enzymes are dispensable in vivo. The dispensability of CS1 and PrpC suggests that either the TCA cycle is not essential for the asexual reproduction of tachyzoites or there are other routes of citrate supply in the parasite mitochondrion.

The effect of Toxoplasma gondii infection on galectin-9 expression in decidual macrophages contributing to dysfunction of decidual NK cells during pregnancy

BACKGROUND

Toxoplasma gondii infection causes adverse pregnancy outcomes by affecting the expression of immunotolerant molecules in decidual immune cells. Galectin-9 (Gal-9) is widely expressed in decidual macrophages (dMφ) and is crucial for maintaining normal pregnancy by interacting with the immunomodulatory protein T-cell immunoglobulin and mucin domain-containing molecule 3 (Tim-3). However, the effects of T. gondii infection on Gal-9 expression in dMφ, and the impact of altered Gal-9 expression levels on the maternal-fetal tolerance function of decidual natural killer (dNK) cells, are still unknown.

METHODS

Pregnancy outcomes of T. gondii-infected C57BL/6 and Lgals9-/- pregnant mice models were recorded. Expression of Gal-9, c-Jun N-terminal kinase (JNK), phosphorylated JNK (p-JNK), and Forkhead box protein O1 (FOXO1) was detected by western blotting, flow cytometry or immunofluorescence. The binding of FOXO1 to the promoter of Lgals9 was determined by chromatin immunoprecipitation-polymerase chain reaction (ChIP-PCR). The expression of extracellular signal-regulated kinase (ERK), phosphorylated ERK (p-ERK), cAMP-response element binding protein (CREB), phosphorylated CREB (p-CREB), T-box expressed in T cells (T-bet), interleukin 10 (IL-10), and interferon gamma (IFN-γ) in dNK cells was assayed by western blotting.

RESULTS

Toxoplasma gondii infection increased the expression of p-JNK and FOXO1 in dMφ, resulting in a reduction in Gal-9 due to the elevated binding of FOXO1 with Lgals9 promoter. Downregulation of Gal-9 enhanced the phosphorylation of ERK, inhibited the expression of p-CREB and IL-10, and promoted the expression of T-bet and IFN-γ in dNK cells. In the mice model, knockout of Lgals9 aggravated adverse pregnancy outcomes caused by T. gondii infection during pregnancy.

CONCLUSIONS

Toxoplasma gondii infection suppressed Gal-9 expression in dMφ by activating the JNK/FOXO1 signaling pathway, and reduction of Gal-9 contributed to dysfunction of dNK via Gal-9/Tim-3 interaction. This study provides new insights for the molecular mechanisms of the adverse pregnancy outcomes caused by T. gondii.

Human toxoplasmosis as a result of swimming with pink dolphins in the Amazon river?

Toxoplasmosis appears to be a common infection among humans, domestic and wild animals in the Manaus region, Amazonas state, Brazil. Tourist activities in this area include swimming with pink dolphins, suspended trails through the forest and visits to indigenous tribes. This case reports the diagnosis of toxoplasmosis should be included in investigations of travellers.

BCC0 collaborates with IMC32 and IMC43 to form the Toxoplasma gondii essential daughter bud assembly complex

Toxoplasma gondii divides by endodyogeny, in which two daughter buds are formed within the cytoplasm of the maternal cell using the inner membrane complex (IMC) as a scaffold. During endodyogeny, components of the IMC are synthesized and added sequentially to the nascent daughter buds in a tightly regulated manner. We previously showed that the early recruiting proteins IMC32 and IMC43 form an essential daughter bud assembly complex which lays the foundation of the daughter cell scaffold in T. gondii. In this study, we identify the essential, early recruiting IMC protein BCC0 as a third member of this complex by using IMC32 as bait in both proximity labeling and yeast two-hybrid screens. We demonstrate that BCC0's localization to daughter buds depends on the presence of both IMC32 and IMC43. Deletion analyses and functional complementation studies reveal that residues 701-877 of BCC0 are essential for both its localization and function and that residues 1-899 are sufficient for function despite minor mislocalization. Pairwise yeast two-hybrid assays additionally demonstrate that BCC0's essential domain binds to the coiled-coil region of IMC32 and that BCC0 and IMC43 do not directly interact. This data supports a model for complex assembly in which an IMC32-BCC0 subcomplex initially recruits to nascent buds via palmitoylation of IMC32 and is locked into the scaffold once bud elongation begins by IMC32 binding to IMC43. Together, this study dissects the organization and function of a complex of three early recruiting daughter proteins which are essential for the proper assembly of the IMC during endodyogeny.

The effect of the HMGB1/RAGE/TLR4/NF-κB signalling pathway in patients with idiopathic epilepsy and its relationship with toxoplasmosis

This study aims to investigate the relationship between toxoplasmosis and this pathway, which may be effective in the formation of epilepsy by acting through the HMGB1/RAGE/TLR4/NF-κB signalling pathway in patients with idiopathic epilepsy. In the study, four different experimental groups were formed by selecting Toxoplasma gondii IgG positive and negative patients with idiopathic epilepsy and healthy controls. Experimental groups were as follows: Group 1: Epilepsy+/Toxo- (E+, T-) (n = 10), Group 2: Epilepsy-/Toxo- (E-, T-) (n = 10), Group 3: Epilepsy-/Toxo+ (E-, T+) (n = 10), Group 4: Epilepsy+/Toxo+ (E+, T+) (n = 10). HMGB1, RAGE, TLR4, TLR1, TLR2, TLR3, IRAK1, IRAK2, IKBKB, IKBKG, BCL3, IL1β, IL10, 1 L8 and TNFα mRNA expression levels in the HMGB/RAGE/TLR4/NF-κB signalling pathway were determined by quantitative simultaneous PCR (qRT-PCR) after collecting blood samples from all patients in the groups. Statistical analysis was performed by one-way ANOVA followed by LSD post-hoc tests, and p < 0.05 was considered to denote statistical significance. The gene expression levels of HMGB1, TLR4, IL10, IL1B, IL8, and TLR2 were significantly higher in the G1 group than in the other groups (p < 0.05). In the G3 group, RAGE and BCL3 gene expression levels were significantly higher than in the other groups (p < 0.05). In the G4 group, however, IRAK2, IKBKB, and IKBKG gene expression levels were significantly higher than in the other groups (p < 0.05). HMGB1, TLR4, IRAK2, IKBKB, IL10, IL1B, IL1B, and IL8 in this signalling pathway are highly expressed in epilepsy patients in G1 and seizures occur with the stimulation of excitatory mechanisms by acting through this pathway. The signalling pathway in epilepsy may be activated by HMGB1, TLR4, and TLR2, which are considered to increase the level of proinflammatory cytokines. In T. gondii, this pathway is activated by RAGE and BCL3.

Detection of Toxoplasma gondii infection in buffaloes (Bubalus bubalis) and cattle (Bos taurus) at the Tabriz abattoir, Iran

BACKGROUND

Toxoplasma gondii is a widely prevalent zoonotic protozoan parasite in humans and warm-blooded animals worldwide. Infection of humans by this parasite can result in severe clinical symptoms, particularly in individuals with congenital toxoplasmosis or immunocompromised patients. Contamination mainly occurs through foodborne routes, especially the consumption of raw or undercooked meat from animals.

OBJECTIVES

The aim of this study was to use PCR to detect T. gondii in tissues and organs of buffaloes and cattle slaughtered at Tabriz slaughterhouse, in Iran.

METHODS

Fifty grams of heart, thigh, diaphragm and tongue from 50 buffaloes and 100 cattle slaughtered at the Tabriz industrial slaughterhouse were selected for sampling using a combination of convenience sampling. The samples were tested using a previously published PCR method.

RESULTS

Out of the 150 animal samples, T. gondii was detected in 10 (6.7%, 95%CI: 3.2-11.9), including one buffalo (2%, 95%CI: 0.1-10.6) and nine cattle (9%, 95%CI: 4.2-16.4). There was no statistically significant difference in the rate of T. gondii infection among cattle based on age and sex (p > 0.05).

CONCLUSIONS

The results indicated a potential risk of T. gondii transmission to humans through the consumption of infected meat. Therefore, appropriate and effective preventive measures should be taken to limit the transmission of this parasite to humans, and the consumption of raw and undercooked meat should be discouraged.

The impact of miRNA-155 in acute and chronic toxoplasmosis in Iraqi women

Toxoplasmosis is a prevalent parasitic infection caused by Toxoplasma gondii known to induce complex immune responses, to control the infection. MicroRNAs (miRNAs) are a cluster of small noncoding RNAs that are reported to have regulatory functions in the immune response. The objective of this study is to assess the expression of miR-155 and its targets, Src homology-2 domain-containing inositol 5- phosphatase 1 (SHIP-1) and suppressor of cytokine signaling-1 (SOCS1), in non-pregnant Iraqi women seropositive for toxoplasmosis. The study included 55 non-pregnant women positive for toxoplasmosis (20 in the acute phase and 35 in the chronic phase) and 35 non-pregnant women negative for toxoplasmosis (control group). Serum samples were collected from all participants to investigate the expression of miR-155 by RT‒PCR, in addition to the levels of SOCS1 and SHIP-1 measured by ELISA. The results showed a significant increase in the expression of miR-155 in both groups of acute and chronic toxoplasmosis compared to the control group. Lower levels of SOCS1 and SHIP-1 were found in acutely infected women compared to those with chronic infection and non-infected women. These findings showed the possible critical impact of miR-155 on host immune response during T.gondii infection, proposing that miR-155 can be explored as a prospective target to support host immune response against infectious diseases, with special help in early detection and management of toxoplasmosis in high-risk immunocompromised patients. Further studies are needed to evaluate the molecular pathways by which miRNAs improve immunity against toxoplasmosis.

Seroprevalence of Toxoplasma gondii, risk factors and knowledge about toxoplasmosis in undergraduate students from Lima, Peru

Toxoplasma gondii is the causative agent of toxoplasmosis, a zoonotic disease of worldwide distribution. The aim of this study was to assess the seroprevalence of T. gondii in undergraduate students from Lima, Peru, and to identify the risk factors linked to the infection. For this, serum samples of 100 undergraduate students of the Faculty of Biological Sciences were tested for T. gondii antibodies with a commercially available ELISA. The seroprevalence of T. gondii in these subjects was 7 %. Only the age of students showed a statistical association with T. gondii seropositivity. The level of awareness regarding toxoplasmosis was also investigated. In the sample, 71 % of the students are aware of toxoplasmosis and 64 % that a parasite is the cause of the infection. Most know it is transmitted through undercooked meat (57 %), but are unaware of contaminated vegetables (40 %), organ transplants (17 %), blood transfusions (32 %), and soil contact (39 %). In the epidemiological context it will be valuable to verify toxoplasmosis awareness in other population groups and other regions in Peru.

One Health Approach to Toxoplasmosis: Owner and Dog Seropositivity as Spatial Indicators of Risk Areas for Acquired, Gestational and Congenital Transmission

BACKGROUND

Toxoplasmosis has been of public health concern due to direct associations with socioeconomic vulnerability and inadequate living conditions.

METHODS

Accordingly, the present study aimed to assess antibodies against T. gondii, historical reported toxoplasmosis cases and associated socio-environmental risk factors in Pinhais, a full urban area of Curitiba, currently the eighth biggest metropolitan area of Brazil. Anti-Toxoplasma gondii antibodies were assessed by an indirect immunofluorescence reaction (RIFI). Owner and dog samples were also tested by IFAT to anti-Leishmania spp. and anti-Trypanosoma cruzi antibodies.

RESULTS

Overall, 20/135 (14.8%) persons and 13/133 (9.8%) dogs from 25 different households were considered seropositive to T. gondii. All samples were seronegative to Leishmania spp. and Trypanosoma cruzi.

CONCLUSIONS

Although no significant covariates were found in the regression model, statistically associated risk factors in the bivariate analysis included no public water use (p = 0.016) and drinking raw milk (p = 0.041) for owners, and obesity (p = 0.028) and tick infestation (p = 0.03) for dogs. In addition, a spatial cluster of T. gondii seropositivity for both owners and their dogs overlapped the location of historic reported cases of human acquired, gestational and congenital toxoplasmosis. Finally, the results herein showed tick infestation as an indicator of socio-environmental risk for T. gondii exposure in the household environment, and dogs may be used as sentinels for human toxoplasmosis cases.

Knowledge Gaps and Educational Opportunities in Congenital Toxoplasmosis: A Narrative Review of Brazilian and Global Perspectives

Congenital toxoplasmosis is a parasitic disease caused by the transmission of the protozoan Toxoplasma gondii during pregnancy that can potentially cause severe consequences for the fetus or neonates. The disease disproportionately impacts the global population and is generally correlated with the Human Development Index. Despite its prevalence, there are knowledge gaps among pregnant women and healthcare providers regarding the prevention, diagnosis, and treatment of this condition. This narrative review aimed to examine the current state of knowledge of toxoplasmosis among both groups, with a focus on exploring the Brazilian and global perspectives and highlighting opportunities for enhancing education and communication. A search was conducted across five databases, and 60 studies were selected (23 in Brazil and 37 worldwide). Quantitative analysis revealed that general knowledge of toxoplasmosis among pregnant women is notably poor, with 66% of Brazilian women and 72% of women worldwide lacking sufficient understanding. Among those with some knowledge, the most recognized association is with cats (46% in Brazil and 38% worldwide), followed by raw or undercooked meat (27% in Brazil and 25% worldwide), and improperly sanitized vegetables or water (15% in Brazil and 21% worldwide). Similarly, gaps in knowledge were found among healthcare providers. Difficulty with IgG avidity test interpretation is higher in Brazil (43%) compared to worldwide (18%). The most recognized association is with cats (66% in Brazil and 74% worldwide), followed by raw or undercooked meat (49% in Brazil and 70% worldwide), and improperly sanitized vegetables or water (31% in Brazil and 32% worldwide). These findings emphasize the need for tailored local and global public health educational initiatives to enhance knowledge of toxoplasmosis among pregnant women and healthcare providers.

Serological and molecular survey of Toxoplasma gondii infection and associated risk factors in urban cats in Kunming, Southwest China

Toxoplasma gondii (T. gondii) is a worldwide zoonotic parasite that can infect almost warm-blood animals, including humans, which seriously affect the health of host. Cats are known to be the only definitive host of T. gondii and continuously excrete highly infectious oocysts. This parasite carried by the companion animals leads to a great public health risk. However, there is little information on epidemiology of T. gondii in urban cats in Kunming, Southwest China. In the present study, a total of 231 serum and fecal samples were collected in Kunming aera, and then seroprevalence of T. gondii IgG antibodies in serum and molecular investigation in feces were analyzed to elucidate T. gondii infection in urban cats. The results revealed that 168 of 231 cats (72.7%) were positive for T. gondii antibodies, and 1 of 74 cat feces (1.4%) also showed a positive PCR for T. gondii DNA. The positive fecal sample was sequenced and then phylogenetically analyzed, and the isolate of T. gondii in the present study was closely related to T. gondii strain CN. In addition, the food, water and age of cats were identified as the risk factor for seropositivity. Overall, our findings indicate the widespread occurrence of T. gondii infection in urban cats in Kunming, Southwest China and identify food, water and age are the risk factors associated with T. gondii infection, which can provide effective information for developing strategies to prevent and control this zoonosis.

Early immune response to Toxoplasma gondii lineage III isolates of different virulence phenotype

Introduction

Toxoplasma gondii is an intracellular parasite of importance to human and veterinary health. The structure and diversity of the genotype population of T. gondii varies considerably with respect to geography, but three lineages, type I, II and III, are distributed globally. Lineage III genotypes are the least well characterized in terms of biology, host immunity and virulence. Once a host is infected with T.gondii, innate immune mechanisms are engaged to reduce the parasite burden in tissues and create a pro-inflammatory environment in which the TH1 response develops to ensure survival. This study investigated the early cellular immune response of Swiss-Webster mice post intraperitoneal infection with 10 tachyzoites of four distinct non-clonal genotypes of lineage III and a local isolate of ToxoDB#1. The virulence phenotype, cumulative mortality (CM) and allele profiles of ROP5, ROP16, ROP18 and GRA15 were published previously.

Methods

Parasite dissemination in different tissues was analyzed by real-time PCR and relative expression levels of IFNγ, IL12-p40, IL-10 and TBX21 in the cervical lymph nodes (CLN), brain and spleen were calculated using the ΔΔCt method. Stage conversion was determined by detection of the BAG1 transcript in the brain.

Results

Tissue dissemination depends on the virulence phenotype but not CM, while the TBX21 and cytokine levels and kinetics correlate better with CM than virulence phenotype. The earliest detection of BAG1 was seven days post infection. Only infection with the genotype of high CM (69.4%) was associated with high T-bet levels in the CLN 24 h and high systemic IFNγ expression which was sustained over the first week, while infection with genotypes of lower CM (38.8%, 10.7% and 6.8%) is characterized by down-regulation and/or low systemic levels of IFNγ. The response intensity, as assessed by cytokine levels, to the genotype of high CM wanes over time, while it increases gradually to genotypes of lower CM.

Discussion

The results point to the conclusion that the immune response is not correlated with the virulence phenotype and/or allele profile, but an early onset, intense pro-inflammatory response is characteristic of genotypes with high CM. Additionally, high IFNγ level in the brain may hamper stage conversion.

Seroprevalence of Toxoplasma gondii and Associated Risk Factors among Pregnant Women in Algeria

Toxoplasma gondii is an obligate intracellular protozoan parasite affecting all warm-blooded vertebrates, including humans. Infections in humans can lead to severe clinical manifestations in pregnant women and immunocompromised patients. The aim of the present study was to assess seroprevalence of T. gondii infection and to identify the associated risk factors among pregnant women from southern Algeria. A cross-sectional study was conducted from March 2021 to May 2022 among 1,345 pregnant women. A structured questionnaire was used to obtain information on risk factors associated with infection. Participants were screened for anti T. gondii IgG and IgM antibodies using the enzyme-linked fluorescent assay. The overall IgG and IgM seroprevalence was 13.6% and 0.89%, respectively. A significant association was found between seroprevalence of anti T. gondii IgG and history of spontaneous abortion (P = 0.016). Moreover, an increasing trend of seroprevalence was detected in the autumnal season (P = 0.030), and eating raw or undercooked meat was found to be significantly associated with anti-T. gondii IgM seropositivity (P = 0.002). Multivariate analysis showed that women who had experienced spontaneous abortion, regularly ate undercooked meat, and used bottled water in summer were more likely to contract infection with T. gondii. The majority (86.4%) of the studied pregnant women were serologically negative for toxoplasmosis and hence were susceptible to primary acute infection during pregnancy and possible fetal anomalies. Therefore, health education and awareness of the disease and its transmission to women, especially during pregnancy, is imperative.

Knockdown of DJ-1 Exacerbates Neuron Apoptosis Induced by TgCtwh3 through the NF-κB Pathway

Mutations or loss of function of DJ-1 and Toxoplasma gondii (T. gondii) infection has been linked to neurodegenerative diseases, which are often caused by oxidative stress. However, the relationship between DJ-1 and T. gondii infection is not yet fully understood. Therefore, this study aimed to investigate the expression of DJ-1 in the hippocampus tissue of mice or in HT22 infected with T. gondii Chinese 1 genotype Wh3 strain (TgCtwh3) and the effect of DJ-1 knockdown on neuronal apoptosis induced by TgCtwh3 tachyzoite, as well as the underlying mechanism at the cellular and molecular level. Firstly, we detected DJ-1 protein expression and cell apoptosis in the hippocampal tissue of mice infected by TgCtwh3. Then, we examined DJ-1 expression and apoptosis in HT22 challenged with TgCtwh3. Finally, we evaluated the apoptosis in HT22 with DJ-1 knockdown which was infected with TgCtwh3 and assayed the expression of NF-κBp65 and p-NF-κBp65. Our results showed that DJ-1 expression was reduced and neurons underwent apoptosis in the hippocampus of mice infected with TgCtwh3 tachyzoites. Additionally, the knockdown of DJ-1 followed by infection with TgCtwh3 tachyzoites led to increased apoptosis in HT22 cells through the NF-κB signaling pathway. Therefore, this study suggests that DJ-1 is an important target for preventing apoptosis caused by T. gondii TgCtwh3.

Seroprevalence and risk factors of Toxoplasma gondii in goats (Capra hircus) in the state of Espírito Santo, Southeast Brazil

Toxoplasma gondii is described as a potential cause of abortion in goats and as a threat to public health. To estimate the prevalence of goats infected by T. gondii, in different cities in the Espírito Santo State, and to identify possible risk factors for infection a serological study was conducted. A total of 146 goat serum samples from the cities of Cariacica, Serra and Vila Velha were analyzed. The presence of IgG Class Immunoglobulins was serologically evaluated by Immunofluorescence antibody test (IFAT) and by Enzyme-linked Immunosorbent Assay (ELISA). The seroprevalence of anti-T. gondii was 46.6% (68/146) in both techniques and the same samples got the same results in both techniques. Among the analyzed sera, 70.6% (48/68) exhibited high-avidity IgG antibodies, and 29.4% (20/68) exhibited low-avidity IgG antibodies, suggesting that the infection was chronic in the infected animals. Female sex, age group over two years old, water from the public supply system, storage of food and supplies in an open and unprotected place, and the presence of a domestic cat on the property were identified as risk factors for T. gondii infection in goats. The state of Espirito Santo has a high frequency of infected goats, and this is the first research on caprine toxoplasmosis seroepidemiology in that region.

Oral Sex as a Potential Route for Toxoplasma Gondii Transmission: Experiment with Human Semen and Laboratory Mice Model

PURPOSE

Toxoplasma gondii is one of the most widespread parasites in the human population globally. Several modes of its transmission have been proposed: some are well-researched and confirmed, others remain unconfirmed. One unconfirmed hypothesis pertains to potential transmission of Toxoplasma gondii via oral sex (fellatio) in humans. A recent study found tissue cysts in the semen of men with latent toxoplasmosis. Therefore, we aimed to test the hypothesis of Toxoplasma gondii transmission through oral sex experimentally.

METHODS

Eighty-two laboratory mice were orally administered semen samples from 41 men with latent toxoplasmosis. These semen samples were examined for the presence of Toxoplasma gondii DNA using PCR.

RESULTS

We detected Toxoplasma gondii DNA in three of the 41 semen samples from men with latent toxoplasmosis. Oral administration of semen samples to laboratory mice did not result in parasite transmission.

CONCLUSION

We have not demonstrated the transmission of Toxoplasma to mice by oral exposure to semen from infected men. While this does not conclusively rule out the possibility of such transmission in humans, the results suggest that, if it does occur, this mode of transmission is likely infrequent.

Toxoplasmosis in animals and humans: a neglected zoonotic disease in Bangladesh

Toxoplasmosis, caused by Toxoplasma gondii, is a zoonotic disease that affects a wide range of warm-blooded animals, including humans. The parasite undergoes both sexual and asexual reproduction in intermediate hosts (humans and animals) and definitive hosts (cats). Transmission in humans occurs through consuming oocyst-contaminated water, fruits, vegetables, and raw or undercooked meats. In Bangladesh, several factors contribute to an increased risk of contracting toxoplasmosis. The parasite is reported to cause diseases among livestock such as goats and sheep in this country, and it has also been associated with some human illnesses. Toxoplasmosis prevalence varies significantly worldwide, with developing countries like Bangladesh experiencing higher rates. Diagnostic methods include both conventional non-DNA-based tests and molecular detection techniques, while treatment options involve using antiparasitic drugs like sulfadiazine and pyrimethamine. To control toxoplasmosis, essential steps include improving sanitation, promoting safe food handling, and educating the public about risks related to cat ownership and undercooked meat consumption. Implementing prenatal screening and treatment is also important. With the growing popularity of pet ownership in urban areas, it becomes essential to emphasize the veterinary and public health significance of toxoplasmosis in Bangladesh. This article comprehensively reviews various aspects of toxoplasmosis, with a specific focus on the situation in Bangladesh.

Prevalence of coccidia in lagomorphs in China between 1981 and 2023: A systematic review and meta-analysis

Lagomorpha coccidiosis, caused by coccidia, is a prevalent disease affecting rabbits, hares and pikas. This meta-analysis aimed to estimate the pooled prevalence of coccidia infection in lagomorphs and identify potential risk factors. A systematic search of six databases yielded 102 studies published between 1981 and 2023. The pooled prevalence of Eimeriidae, Sarcocystidae and Cryptosporidiidae in lagomorphs was 76.4%, 6.2% and 3.9%, respectively. Rabbits had the highest prevalence of Eimeriidae (76.8%) and Sarcocystidae (7.4%), while pikas had the highest prevalence of Cryptosporidiidae (6.2%). Juvenile rabbits exhibited the highest prevalence of Eimeriidae (84.6%) and Cryptosporidiidae (9.9%). Northwest China had the highest prevalence of Eimeriidae (87.8%). Over time, the prevalence of Eimeriidae declined (Coefficient: -0.0062; P<0.05), but remained high (65.0%) in the past five years. Our findings highlight the prevalence of Eimeriidae infection in lagomorphs and the need for further research on Sarcocystidae and Cryptosporidiidae infections. We emphasize the importance of developing lagomorpha coccidia vaccines and implementing vaccination schedules for juvenile rabbits to mitigate coccidia infections.

Effective factors in the pathogenesis of Toxoplasmagondii

Toxoplasma gondii (T. gondii) is a cosmopolitan protozoan parasite in humans and animals. It infects about 30 % of the human population worldwide and causes potentially fatal diseases in immunocompromised hosts and neonates. For this study, five English-language databases (ScienceDirect, ProQuest, Web of Science, PubMed, and Scopus) and the internet search engine Google Scholar were searched. This review was accomplished to draw a global perspective of what is known about the pathogenesis of T. gondii and various factors affecting it. Virulence and immune responses can influence the mechanisms of parasite pathogenesis and these factors are in turn influenced by other factors. In addition to the host's genetic background, the type of Toxoplasma strain, the routes of transmission of infection, the number of passages, and different phases of parasite life affect virulence. The identification of virulence factors of the parasite could provide promising insights into the pathogenesis of this parasite. The results of this study can be an incentive to conduct more intensive research to design and develop new anti-Toxoplasma agents (drugs and vaccines) to treat or prevent this infection. In addition, further studies are needed to better understand the key agents in the pathogenesis of T. gondii.

Assessing the impact of preventative measures to limit the spread of Toxoplasma gondii in wild carnivores of Madagascar

Novel multihost pathogens can threaten endangered wildlife species, as well as humans and domestic animals. The zoonotic protozoan parasite Toxoplasma gondii is transmitted by members of Felidae and can infect a large number of animal species, including humans. This parasite can have significant health consequences for infected intermediate hosts and could further endanger wild carnivore populations of Madagascar. Building on an empirical characterization of the prevalence of the pathogen in local mammals, we used mathematical models of pathogen transmission in a multihost community to compare preventative measures that aim to limit the spread of this parasite in wild carnivores. Specifically, we examined the effect of hypothetical cat vaccination and population control campaigns on reducing the risk of infection by T. gondii in wild Eupleridae. Our model predicted that the prevalence of exposure to T. gondii in cats would be around 72% and that seroprevalence would reach 2% and 43% in rodents and wild carnivores, respectively. Reducing the rodent population in the landscape by half may only decrease the prevalence of T. gondii in carnivores by 10%. Similarly, cat vaccination and reducing the population of definitive hosts had limited impact on the prevalence of T. gondii in wild carnivorans of Madagascar. A significant reduction in prevalence would require extremely high vaccination, low turnover, or both in the cat population. Other potential control methods of T. gondii in endangered Eupleridae include targeted vaccination of wild animals but would require further investigation. Eliminating the threat entirely will be difficult because of the ubiquity of cats and the persistence of the parasite in the environment.

Characterization and functional analysis of Toxoplasma Golgi-associated proteins identified by proximity labelling

Toxoplasma gondii possesses a highly polarized secretory pathway that contains both broadly conserved eukaryotic organelles and unique apicomplexan organelles which play essential roles in the parasite's lytic cycle. As in other eukaryotes, the T. gondii Golgi apparatus sorts and modifies proteins prior to their distribution to downstream organelles. Many of the typical trafficking factors found involved in these processes are missing from apicomplexan genomes, suggesting that these parasites have evolved unique proteins to fill these roles. Here we identify a novel Golgi-localizing protein (ULP1) which contains structural homology to the eukaryotic trafficking factor p115/Uso1. We demonstrate that depletion of ULP1 leads to a dramatic reduction in parasite fitness and replicative ability. Using ULP1 as bait for TurboID proximity labelling and immunoprecipitation, we identify eleven more novel Golgi-associated proteins and demonstrate that ULP1 interacts with the T. gondii COG complex. These proteins include both conserved trafficking factors and parasite-specific proteins. Using a conditional knockdown approach, we assess the effect of each of these eleven proteins on parasite fitness. Together, this work reveals a diverse set of novel T. gondii Golgi-associated proteins that play distinct roles in the secretory pathway. As several of these proteins are absent outside of the Apicomplexa, they represent potential targets for the development of novel therapeutics against these parasites.

Importance

Apicomplexan parasites such as Toxoplasma gondii infect a large percentage of the world's population and cause substantial human disease. These widespread pathogens use specialized secretory organelles to infect their host cells, modulate host cell functions, and cause disease. While the functions of the secretory organelles are now better understood, the Golgi apparatus of the parasite remains largely unexplored, particularly regarding parasite-specific innovations that may help direct traffic intracellularly. In this work, we characterize ULP1, a protein that is unique to parasites but shares structural similarity to the eukaryotic trafficking factor p115/Uso1. We show that ULP1 plays an important role in parasite replication and demonstrate that it interacts with the conserved oligomeric Golgi (COG) complex. We then use ULP1 proximity labelling to identify eleven additional Golgi-associated proteins which we functionally analyze via conditional knockdown. This work expands our knowledge of the Toxoplasma Golgi apparatus and identifies potential targets for therapeutic intervention.

TBC9, an essential TBC-domain protein, regulates early vesicular transport and IMC formation in Toxoplasma gondii

Apicomplexan parasites harbor a complex endomembrane system as well as unique secretory organelles. These complex cellular structures require an elaborate vesicle trafficking system, which includes Rab GTPases and their regulators, to assure the biogenesis and secretory of the organelles. Here we exploit the model apicomplexan organism Toxoplasma gondii that encodes a family of Rab GTPase Activating Proteins, TBC (Tre-2/Bub2/Cdc16) domain-containing proteins. Functional profiling of these proteins in tachyzoites reveals that TBC9 is the only essential regulator, which is localized to the endoplasmic reticulum (ER) in T. gondii strains. Detailed analyses demonstrate that TBC9 is required for normal distribution of proteins targeting to the ER, and the Golgi apparatus in the parasite, as well as for the normal formation of daughter inner membrane complexes (IMCs). Pull-down assays show a strong protein interaction between TBC9 and specific Rab GTPases (Rab11A, Rab11B, and Rab2), supporting the role of TBC9 in daughter IMC formation and early vesicular transport. Thus, this study identifies the only essential TBC domain-containing protein TBC9 that regulates early vesicular transport and IMC formation in T. gondii and potentially in closely related protists.

Molecular evidence of Toxoplasma gondii from the tissue and blood of naturally infected sheep

Toxoplasmosis is a cosmopolitan zoonotic infection that has significant effects on public health and causes economic losses in the livestock industry. The current study was designed to detect the Toxoplasma parasite in sheep blood samples and tissue samples of slaughtered sheep at the Sulaimani abattoir using molecular technique. A total of 300 peripheral sheep blood samples were randomly collected from 20 small ruminant flocks at 4 locations in the Sulaymaniyah province, northern Iraq. Also, 150 meat samples from thigh muscle, heart, and diaphragm were collected from slaughtered sheep. All collected blood samples were subjected to polymerase chain reaction (PCR) amplification to confirm Toxoplasma infection; in addition, meat samples were also analyzed for Toxoplasma by PCR following the digestion process. Of the 300 amplified blood samples, 94 were considered positive for Toxoplasma gondii, with a prevalence rate of 31.3%. The overall prevalence of Toxoplasma among meat samples was 34%. The diaphragm reported a higher infection rate (46%) than the heart (32%), while the femoral muscle reported an infection rate of 24%. Aged animals (older than 24 months) presented a higher infection rate (32.8%) than younger animals (28.9%). Contact with or consumption of uncooked meat from infected sheep increases the chance of parasite transmission to humans.

Comparison of Direct and Indirect Detection of Toxoplasma gondii in Ovine Using Real-Time PCR, Serological and Histological Techniques

Toxoplasma gondii is a zoonotic pathogen and the ingestion of tissue cysts by consumption of lamb or mutton has been identified as a possible cause of infection in humans. Many serological surveys in sheep have been performed, showing relevant serological rates; however, while the detection of antibodies indicates an exposure to T. gondii, this does not necessarily imply the presence of tissue cysts in edible tissue. The current study aims to provide further understanding on the occurrence of T. gondii in sheep muscles and the strength of correlation between serological positivity and presence of the parasite in sheep. From 349 sheep, samples (i.e., blood, heart and diaphragm) were collected and subjected to ELISA tests, real-time PCR and histological tests. Despite the high seroprevalence, T. gondii DNA was detected in the heart and/or the diaphragm from 13 out of the 349 tested sheep (3.7%); all were adults (13/191). Furthermore, the histological tests did not reveal the presence of T. gondii tissue cysts in any of the examined portions of interventricular septum. It should be considered that the likelihood of detecting genetic material of the parasite is probably influenced by the uneven distribution of the tissue cysts in the carcass as well as the methodology applied. The findings of this study support the importance of describing the uncertainty associated with the data used for risk assessment to reduce inaccurate estimation or risk overestimation.

In vitro assay to determine inactivation of Toxoplasma gondii in meat samples

Consumption of raw and undercooked meat is considered as an important source of Toxoplasma gondii infections. However, most non-heated meat products contain salt and additives, which affect T. gondii viability. It was our aim to develop an in vitro method to substitute the mouse bioassay for determining the effect of salting on T. gondii viability. Two sheep were experimentally infected by oral inoculation with 6.5 × 104 oocysts. Grinded meat samples of 50 g were prepared from heart, diaphragm, and four meat cuts. Also, pooled meat samples were either kept untreated (positive control), frozen (negative control) or supplemented with 0.6 %, 0.9 %, 1.2 % or 2.7 % NaCl. All samples were digested in pepsin-HCl solution, and digests were inoculated in duplicate onto monolayers of RK13 (a rabbit kidney cell line). Cells were maintained for up to four weeks and parasite growth was monitored by assessing Cq-values using the T. gondii qPCR on cell culture supernatant in intervals of one week and ΔCq-values determined. Additionally, 500 μL of each digest from the individual meat cuts, heart and diaphragm were inoculated in duplicate in IFNγ KO mice. Both sheep developed an antibody response and tissue samples contained similar concentrations of T. gondii DNA. From all untreated meat samples positive ΔCq-values were obtained in the in vitro assay, indicating presence and multiplication of viable parasites. This was in line with the mouse bioassay, with the exception of a negative mouse bioassay on one heart sample. Samples supplemented with 0.6 %-1.2 % NaCl showed positive ΔCq-values over time. The frozen sample and the sample supplemented with 2.7 % NaCl remained qPCR positive but with high Cq-values, which indicated no growth. In conclusion, the in vitro method has successfully been used to detect viable T. gondii in tissues of experimentally infected sheep, and a clear difference in T. gondii viability was observed between the samples supplemented with 2.7 % NaCl and those with 1.2 % NaCl or less.

Helicobacter pylori-Toxoplasma gondii interplay with a possible role of IL-10

Parasites are known for their modulatory effects on the immune response. The impact of toxoplasmosis on the immune response towards H. pylori is being studied in terms of IL-10 levels. This study included 110 patients suffering from persistent dyspepsia and 50 apparently healthy controls. Stool samples were collected and tested for H. pylori using colloidal gold one step test. Sera were examined for anti-Toxoplasma IgM and IgG using ELISA. IL-10 was also tested in the sera using ELISA. We found that Toxoplasma IgM and IgG tested positive in 1.8 % and 40 % of H. pylori positive patients, respectively. H. pylori-infected patients displayed higher IL-10 levels than the healthy controls (84 versus 0.59 pg/ml, respectively, P < 0.001). Classification of H. pylori positive patients according to Toxoplasma IgG titers yielded three groups: negative (58, 52.7 %), equivocal (8, 7.3 %), and positive (44, 40 %) groups, with the highest IL-10 levels detected in the double positive than the negative and the equivocal group (215 pg/ml versus 43 and 112.5 pg/ml, respectively, P < 0.001). There was strong positive correlation between Toxoplasma IgG titers and IL-10 levels (rs = 0.82, P < 0.001). Toxoplasma enhances IL-10 production in response to H. pylori infection. This could ameliorate the inflammatory response in the gastric mucosa, and subsequently more colonization with the H. pylori is achieved, resulting in persistent infection.

Systematic characterization of all Toxoplasma gondii TBC domain-containing proteins identifies an essential regulator of Rab2 in the secretory pathway

Toxoplasma gondii resides in its intracellular niche by employing a series of specialized secretory organelles that play roles in invasion, host cell manipulation, and parasite replication. Rab GTPases are major regulators of the parasite's secretory traffic that function as nucleotide-dependent molecular switches to control vesicle trafficking. While many of the Rab proteins have been characterized in T. gondii, precisely how these Rabs are regulated remains poorly understood. To better understand the parasite's secretory traffic, we investigated the entire family of Tre2-Bub2-Cdc16 (TBC) domain-containing proteins, which are known to be involved in vesicle fusion and secretory protein trafficking. We first determined the localization of all 18 TBC domain-containing proteins to discrete regions of the secretory pathway or other vesicles in the parasite. Second, we use an auxin-inducible degron approach to demonstrate that the protozoan-specific TgTBC9 protein, which localizes to the endoplasmic reticulum (ER), is essential for parasite survival. Knockdown of TgTBC9 results in parasite growth arrest and affects the organization of the ER and mitochondrial morphology. TgTBC9 knockdown also results in the formation of large lipid droplets (LDs) and multi-membranous structures surrounded by ER membranes, further indicating a disruption of ER functions. We show that the conserved dual-finger active site in the TBC domain of the protein is critical for its GTPase-activating protein (GAP) function and that the Plasmodium falciparum orthologue of TgTBC9 can rescue the lethal knockdown. We additionally show by immunoprecipitation and yeast 2 hybrid analyses that TgTBC9 preferentially binds Rab2, indicating that the TBC9-Rab2 pair controls ER morphology and vesicular trafficking in the parasite. Together, these studies identify the first essential TBC protein described in any protozoan and provide new insight into intracellular vesicle trafficking in T. gondii.

Humane Endpoints in Swiss Webster Mice Infected with Toxoplasma gondii RH Strain

The highly virulent Toxoplasma gondii RH strain is maintained through successive passages in mice, but there is still a lack of studies that refine these procedures from a 3Rs perspective, where humanitarian ideals aim to minimize the stress, pain, or suffering of the animals used in the research without the loss of results. The aim of this study was to establish humane endpoints in Swiss Webster mice inoculated with the T. gondii RH strain. A total of 52 mice were infected with 5 × 106 tachyzoites/mL and monitored for periods of up to 5 days. The parameters body weight; hair condition; higher than normal body temperature; hypothermia; respiratory function; pain; soft stools or diarrhea; bloody diarrhea; tense, nervous, or in distress during handling; and ascites were recorded daily in score tables. The results showed that prominent piloerection, respiratory function, pain parameters, and ascites are important clinical signs to be used as a cut-off point for implementing euthanasia. The application of this refinement method helped to avoid animal suffering and pain without compromising the number of parasites recovered. We therefore suggest adopting these parameters in research protocols that require the maintenance of the T. gondii RH strain in murine models to avoid and reduce animal suffering.

Cognitive Effects of Toxoplasma and CMV Infections: A Cross-Sectional Study of 557 Young Adults Considering Modulation by Sex and Rh Factor

One-third of humanity harbors a lifelong infection with Toxoplasma gondii, and probably about 80% are infected with human cytomegalovirus (CMV). This study aims to delineate the associations between toxoplasmosis and cognitive abilities and compare these to the associations with CMV. We evaluated the cognitive performance of 557 students, who had been examined for Toxoplasma and CMV infections, using intelligence, memory, and psychomotor tests. The results indicated cognitive impairments in seropositive individuals for both pathogens, with variations in cognitive impact related to sex and the Rh factor. Specifically, Toxoplasma infection was associated with lower IQ in men, whereas CMV was predominantly associated with worse performance by women when testing memory and reaction speeds. Analysis of the antibody concentrations indicated that certain Toxoplasma-associated cognitive detrimental effects may wane (impaired intelligence) or worsen (impaired reaction times) over time following infection. The findings imply that the cognitive impairments caused by both neurotropic pathogens are likely due to pathological changes in the brain rather than from direct manipulative action by the parasites.

Seroprevalence and molecular detection of Toxoplasma gondii and Neospora caninum in beef cattle and goats in Hunan province, China

BACKGROUND

Toxoplasma gondii and Neospora caninum are closely related protozoan parasites that are considered important causes of abortion in livestock, causing huge economic losses. Hunan Province ranks 12th in the production of beef and mutton in China. However, limited data are available on the seroprevalence, risk factors and molecular characterization of T. gondii and N. caninum in beef cattle and goats in Hunan province, China.

METHODS

Sera of 985 beef cattle and 1147 goats were examined for the presence of specific antibodies against T. gondii using indirect hemagglutination test (IHAT) and anti-N. caninum IgG using competitive-inhibition enzyme-linked immunoassay assay (cELISA). Statistical analysis of possible risk factors was performed using PASW Statistics. Muscle samples of 160 beef cattle and 160 goats were examined for the presence of T. gondii DNA (B1 gene) and N. caninum DNA (Nc-5 gene) by nested PCR. The B1 gene-positive samples were genotyped at 10 genetic markers using the multilocus nested PCR-RFLP (Mn-PCR-RFLP).

RESULTS

Specific IgG against T. gondii were detected in 8.3% (82/985) and 13.3% (153/1147) and against N. caninum in 2.1% (21/985) and 2.0% (23/1147) of the beef cattle and goats, respectively. Based on statistical analysis, the presence of cats, semi-intensive management mode and gender were identified as significant risk factors for T. gondii infection in beef cattle. Age was a significant risk factor for T. gondii infection in goats (P < 0.05), and age > 3 years was a significant risk factor for N. caninum infection in beef cattle (P < 0.05). PCR positivity for T. gondii was observed in three beef samples (1.9%; 3/160) and seven chevon samples (4.4%; 7/160). Genotyping of PCR positive samples identified one to be ToxoDB#10. The N. caninum DNA was observed in one beef sample (0.6%; 1/160) but was negative in all chevon samples.

CONCLUSIONS

To our knowledge, this is the first large-scale serological and molecular investigation of T. gondii and N. caninum and assessment of related risk factors in beef cattle and goats in Hunan Province, China. The findings provide baseline data for executing prevention and control of these two important parasites in beef cattle and goats in China.

Toxoplasma gondii in a Remote Subsistence Hunting-Based Indigenous Community of the Peruvian Amazon

Toxoplasma gondii is a ubiquitous zoonotic protozoan parasite that infects a wide variety range of warm-blooded animals. This study describes the epidemiological scenario of T. gondii in an indigenous community that relies on subsistence hunting in a well-conserved and isolated area of the Peruvian Amazon. The high seropositivity against T. gondii in humans (83.3% IgG and 6.1% IgM), wild mammals (30.45%, 17 species), peri-domestic rodents (10.0% Rattus sp.), and domestic animals (94.1% dogs and 100% cats) indicates the existence of a sylvatic cycle in the community under study. Individual age was found to be positively associated with IgG detection against T. gondii but not with IgM. It is estimated that each family consumed 5.67 infected animals per year with terrestrial species having higher infective rates than arboreal species. The main risk factors included improper handling and cooking of wild meat, poor hygiene practices, and feeding uncooked offal to domestic animals. This scenario results in a continuous process of infection and reinfection within the indigenous community with cats, dogs, and peri-domestic animals becoming infected through the ingestion of infected raw viscera. Our results emphasize the need to promote safe food handling practices and disposal of waste materials from hunted animals in such communities.

Ontological representation, modeling, and analysis of parasite vaccines

BACKGROUND

Pathogenic parasites are responsible for multiple diseases, such as malaria and Chagas disease, in humans and livestock. Traditionally, pathogenic parasites have been largely an evasive topic for vaccine design, with most successful vaccines only emerging recently. To aid vaccine design, the VIOLIN vaccine knowledgebase has collected vaccines from all sources to serve as a comprehensive vaccine knowledgebase. VIOLIN utilizes the Vaccine Ontology (VO) to standardize the modeling of vaccine data. VO did not model complex life cycles as seen in parasites. With the inclusion of successful parasite vaccines, an update in parasite vaccine modeling was needed.

RESULTS

VIOLIN was expanded to include 258 parasite vaccines against 23 protozoan species, and 607 new parasite vaccine-related terms were added to VO since 2022. The updated VO design for parasite vaccines accounts for parasite life stages and for transmission-blocking vaccines. A total of 356 terms from the Ontology of Parasite Lifecycle (OPL) were imported to VO to help represent the effect of different parasite life stages. A new VO class term, 'transmission-blocking vaccine,' was added to represent vaccines able to block infectious transmission, and one new VO object property, 'blocks transmission of pathogen via vaccine,' was added to link vaccine and pathogen in which the vaccine blocks the transmission of the pathogen. Additionally, our Gene Set Enrichment Analysis (GSEA) of 140 parasite antigens used in the parasitic vaccines identified enriched features. For example, significant patterns, such as signal, plasma membrane, and entry into host, were found in the antigens of the vaccines against two parasite species: Plasmodium falciparum and Toxoplasma gondii. The analysis found 18 out of the 140 parasite antigens involved with the malaria disease process. Moreover, a majority (15 out of 54) of P. falciparum parasite antigens are localized in the cell membrane. T. gondii antigens, in contrast, have a majority (19/24) of their proteins related to signaling pathways. The antigen-enriched patterns align with the life cycle stage patterns identified in our ontological parasite vaccine modeling.

CONCLUSIONS

The updated VO modeling and GSEA analysis capture the influence of the complex parasite life cycles and their associated antigens on vaccine development.

Co-infection by Toxoplasma gondii and Neospora caninum in Goats Reared in Extensive System of Mexico

Background: The aim of the present study was to describe the presence of co-infection by Toxoplasma gondii and Neospora caninum in goats reared in extensive systems from Mexico. Materials and Methods: A cross-sectional study was conducted to determine the frequency of T. gondii and N. caninum, by detecting antibodies to each parasite by mean commercial ELISA kits. A total of 176 blood samples were randomly collected from mature females reared in extensive system herds from 20 municipalities of state of Guanajuato, Mexico. Results: The general seroprevalence was 23.9 and 21.0% for T. gondii and N. caninum, respectively, while co-infection rate was 3.6%. For geographic and environmental variables, no differences were observed among T. gondii and coinfection; however, it was observed that altitude, annual precipitation, annual average temperature, and rainy period showed significant differences with N. caninum seropositive goats. Conclusion: The seroprevalence of both parasites was appreciated in most of the studied herds. The present study is the first report of T. gondii and N. caninum co-infection in goats from extensive herds in Mexico.

An investigation into Toxoplasma gondii at the human-livestock-wildlife interface, South Africa

Interface areas shared by humans, domestic and wild animals may serve as high transmission contexts for Toxoplasma gondii. However, knowledge about the epidemiology of T. gondii in such areas is currently limited. The present study assessed the seroprevalence of T. gondii in different hosts from Mpumalanga, South Africa. Furthermore, we investigated the local knowledge and related practices about T. gondii by conducting a questionnaire study in the community. Blood samples were obtained and analysed for T. gondii antibodies using a commercial multispecies latex agglutination kit. The seroprevalence detected in humans (n = 160; patients showing signs of acute febrile illness), cats (n = 9), chickens (n = 336) and goats (n = 358) was 8.8%, 0.0%, 4.2% and 11.2%, respectively. Seroprevalence in impalas (n = 97), kudus (n = 55), wild dogs (n = 54), wildebeests (n = 43), warthogs (n = 97) and zebras (n = 68) was calculated at 5.2%, 7.3%, 100.0%, 20.9%, 13.4% and 9.1%, respectively. The questionnaire revealed that 63.0% of household owners were subsistence farmers, and 35.9% were pet owners. A high level of female participation was found (75.3%) when compared to male participation (24.7%). The results show a low circulation of T. gondii in the domestic cycle and suggest the presence of possible bridges between the wildlife cycle and the surrounding domestic cycle.Contribution: The study contributes to identifying transmission patterns and risk factors of T. gondii within human and animal populations. This topic fits within the scope of the journal presenting original research in veterinary science, with the focus on wild and domestic populations on the African continent on a topic of universal importance.

Toxoplasma gondii Infection in Humans: A Comprehensive Approach Involving the General Population, HIV-Infected Patients and Intermediate-Duration Fever in the Canary Islands, Spain

A prior investigation in 1993 identified a high seroprevalence of toxoplasmosis (63%) in the Canary Islands. This study aims to assess the current prevalence of the disease in diverse population groups. The study was based on a population-scale screening involving 273 residents utilizing T. gondii IgG ELISA and a 20 year retrospective study (1998-2018). This included AIDS/HIV outpatients (1357, of which 324 were residents), AIDS/HIV hospitalized patients (741) and patients with fever of intermediate duration (158). The seroprevalence in the resident population was 37%, with significant differences between islands. Among resident outpatients with AIDS/HIV, 14.2% had specific anti-T. gondii IgG, and three had anti-T. gondii IgM; however, IgG avidity testing indicated non-active infection. In patients hospitalized for AIDS/HIV, T. gondii causing encephalitis was detected in 2%. Among patients with fever of intermediate duration, 28.5% were positive for T. gondii IgG, and four also showed IgM positivity, although the infection was non-active. The study reveals a decrease in human toxoplasmosis over the past 30 years. However, the current seroprevalence, which stands at 37%, together with the substantial risk that T. gondii represents for immunocompromised individuals, highlights the need to implement preventive and control strategies to control the threat that this infection can pose to public health in the Canary Islands population.

Toxoplasma gondii infection and testosterone alteration: A systematic review and meta-analyses

BACKGROUND

Toxoplasma gondii (T. gondii) is a worldwide distributed protozoan parasite which has infected a wide range of warm-blooded animals and humans. The most common form of T. gondii infection is asymptomatic (latent); nevertheless, latent toxoplasmosis can induce various alterations of sex hormones, especially testosterone, in infected humans and animals. On the other hand, testosterone is involved in behavioral traits and reproductive functions in both sexes. Hence, the purpose of this systematic review is to summarize the available evidence regarding the association between T. gondii infection and testosterone alteration.

METHODS

In the setting of a systematic review, an electronic search (any date to 10 January 2023) without language restrictions was performed using Science Direct, Web of Science, PubMed, Scopus, and Google Scholar. The PRISMA guidelines were followed. Following the initial search, a total of 12,306 titles and abstracts were screened initially; 12,281 were excluded due to the lack of eligibility criteria or duplication. Finally, 24 articles met the included criteria. A mean±standard deviation (SD) was calculated to assess the difference of testosterone between T. gondii positive and T. gondii negative humans. The possibility of publication bias was assessed using Egger's regression. P-value < 0.05 was considered statistically significant.

RESULTS

This systematic review identified 24 articles (18 studies in humans and six studies in animals). Most human studies (13 out of 19) reported an increased level of testosterone following latent toxoplasmosis in males, while three studies reported decreased levels and two studies reported an insignificant change. Eleven articles (seven datasets in males and seven datasets in females) were eligible to be included in the data synthesis. Based on the random-effects model, the pooled mean± SD of testosterone in T. gondii positive than T. gondii negative was increased by 0.73 and 0.55 units in males and females, respectively. The Egger's regression did not detect a statistically significant publication bias in males and females (p = value = 0.95 and 0.71), respectively. Three studies in male animals (rats, mice, and spotted hyenas) and two studies in female animals (mice and spotted hyenas) reported a decline in testosterone in infected compared with non-infected animals. While, one study in female rats reported no significant changes of testosterone in infected than non-infected animals. Moreover, two studies in male rats reported an increased level of testosterone in infected than non-infected animals.

CONCLUSIONS

This study provides new insights about the association between T. gondii infection and testosterone alteration and identifies relevant data gaps that can inform and encourage further studies. The consequence of increased testosterone levels following T. gondii infection could partly be associated with increased sexual behavior and sexual transmission of the parasite. On the other hand, declining testosterone levels following T. gondii infection may be associated with male reproductive impairments, which were observed in T. gondii-infected humans and animals. Furthermore, these findings suggest the great need for more epidemiological and experimental investigations in depth to understand the relationship between T. gondii infection and testosterone alteration alongside with future consequences of testosterone alteration.

Deciphering the epidemiological dynamics: Toxoplasma gondii seroprevalence in mainland China's food animals, 2010-2023

Background

Toxoplasma gondii (T. gondii) is a significant protozoan pathogen among food animals. Despite the threat to public health by T. gondii infections, there's limited understanding of its seroprevalence and trends in food animals across mainland China. This study aimed to estimate the seroprevalence of T. gondii infections among swine, sheep, goats, chickens, and cattle in mainland China from 2010 to 2023.

Methods

We searched cross-sectional studies published between 2010 and 2023 that reported the prevalence of T. gondii in food animals from databases including PubMed, Embase, Web of Science, China Biology Medicine Disc (CBM), China National Knowledge Infrastructure (CNKI), Wanfang data, and the China Science and Technology Journal Database (CQVIP). We performed subgroup analyses to explore the impact of different factors on the seroprevalence of T. gondii. Pooled estimates of T. gondii seroprevalence were calculated with a random-effects model.

Results

An analysis of 184 studies involving 211985 animals revealed a T. gondii overall seroprevalence of 15.3% (95% CI: 13.1-17.8). Although the seroprevalence of food animals across mainland China was relatively stable from 2010 to 2023, notable variations were observed across different animal types and regions (P < 0.01), along with changes in geographical distribution. Sample type, detection method, animal age, and history of abortion were identified as key risk factors for T. gondii seroprevalence.

Conclusion

The study conducted a meta-analysis on the seroprevalence of T. gondii in mainland China's Food Animals from 2010 to 2023, and identified key risk factors. These findings advance our understanding of T. gondii infection dynamics, offering critical insights for developing control strategies and guiding public health policies.

Expansion microscopy of apicomplexan parasites

Apicomplexan parasites comprise significant pathogens of humans, livestock and wildlife, but also represent a diverse group of eukaryotes with interesting and unique cell biology. The study of cell biology in apicomplexan parasites is complicated by their small size, and historically this has required the application of cutting-edge microscopy techniques to investigate fundamental processes like mitosis or cell division in these organisms. Recently, a technique called expansion microscopy has been developed, which rather than increasing instrument resolution like most imaging modalities, physically expands a biological sample. In only a few years since its development, a derivative of expansion microscopy known as ultrastructure-expansion microscopy (U-ExM) has been widely adopted and proven extremely useful for studying cell biology of Apicomplexa. Here, we review the insights into apicomplexan cell biology that have been enabled through the use of U-ExM, with a specific focus on Plasmodium, Toxoplasma and Cryptosporidium. Further, we summarize emerging expansion microscopy modifications and modalities and forecast how these may influence the field of parasite cell biology in future.

Immunoinformatics studies and design of a novel multi-epitope peptide vaccine against Toxoplasma gondii based on calcium-dependent protein kinases antigens through an in-silico analysis

Purpose

Infection by the intracellular apicomplexan parasite Toxoplasma gondii has serious clinical consequences in humans and veterinarians around the world. Although about a third of the world's population is infected with T. gondii, there is still no effective vaccine against this disease. The aim of this study was to develop and evaluate a multimeric vaccine against T. gondii using the proteins calcium-dependent protein kinase (CDPK)1, CDPK2, CDPK3, and CDPK5.

Materials and Methods

Top-ranked major histocompatibility complex (MHC)-I and MHC-II binding as well as shared, immunodominant linear B-cell epitopes were predicted and linked using appropriate linkers. Moreover, the 50S ribosomal protein L7/L12 (adjuvant) was mixed with the construct's N-terminal to increase the immunogenicity. Then, the vaccine's physicochemical characteristics, antigenicity, allergenicity, secondary and tertiary structure were predicted.

Results

The finally-engineered chimeric vaccine had a length of 680 amino acids with a molecular weight of 74.66 kDa. Analyses of immunogenicity, allergenicity, and multiple physiochemical parameters indicated that the constructed vaccine candidate was soluble, non-allergenic, and immunogenic, making it compatible with humans and hence, a potentially viable and safe vaccine candidate against T. gondii parasite.

Conclusion

In silico, the vaccine construct was able to trigger primary immune responses. However, further laboratory studies are needed to confirm its effectiveness and safety.

Revealing the Prevalence of Toxoplasma in Sierra Morena's Wild Boar: An ELISA-Based Study Using Meat Juice

This research work focused on the prevalence of Toxoplasma gondii in wild boar from the Sierra Morena region. We conducted an ELISA analysis using meat juice samples. A total of 892 samples from six hunting seasons (2013-2019) were collected from the provinces that constitute the Sierra Morena Mountain range. These samples were analyzed using the Pigtype® ELISA kit, specifically developed for detecting T. gondii in meat juice. The overall prevalence of T. gondii in Sierra Morena was 23.2%. The highest prevalences were observed in Córdoba (31.6%) and Jaén (25.9%). These provinces exhibit the highest density of wild boar as well as the greatest presence of the Iberian lynx (Lynx pardinus). Further in-depth studies are necessary, but it appears that the presence of wild felids and scavenger behavior may be associated with this observation.

Seroprevalence and risk factors of Toxoplasma gondii in sheep and goats of North West Province, South Africa

BACKGROUND

The protozoan parasite Toxoplasma gondii causes toxoplasmosis, one of the most prevalent parasitic zoonotic diseases with significant economic and public health implications worldwide. Infection with the parasite has a significant adverse effect on sheep and goat production and can frequently go undetected in the herd, resulting in abortions and weak or dead offspring. Although there are few studies on seroprevalence and risk factors associated with T. gondii infections in livestock in other provinces of South Africa, there is no data in the North West province. Therefore, a cross-sectional study was conducted to investigate the seroprevalence of T. gondii and risk factors associated with exposure in sheep and goats of the North West province of South Africa. Sera from 439 livestock (164 sheep and 285 goats) were collected and analysed for the presence of T. gondii IgG antibodies using indirect ELISA (Enzyme-linked immunosorbent assay). An assessment of potential risk factors in farms associated with seropositivity was also conducted using a structured questionnaire.

RESULTS

Out of the 439 tested sheep and goats, 13.9% (61/439) were positive for IgG antibodies against T. gondii. Sheep and goats had seroprevalences of 19.5% (32/164) and 10.5% (29/275) respectively. In the multivariable logistic regression model, the risk of acquiring T. gondii was significantly higher in the mixed breed [Odds ratio (OR) = 71.07; 95% confidence interval (CI): 266.8-1893.1; p < 0.011)] animals than white dorper sheep and in farms that burn or bury aborted material (OR = 42.04; CI: 179.9-982.5; p = 0.020) compared to those that only burn aborted material. The risk was lower for the farms in Kagisano-Molopo (OR = 0.00; CI: 0.0-25.4; p = 0.015) and Mahikeng (OR = 0.00; CI: 0.0-4.9; p < 0.001) local municipalities than Greater Taung local municipality, and for the animals that drink water from dams (OR = 0.03; CI: 0.2-58.8; p = 0.021) than those that drink from boreholes.

CONCLUSION

The seroprevalence and risk factors associated with transmission observed show that T. gondii infection is widespread in sheep and goats of the North West province.

Observational longitudinal study on Toxoplasma gondii infection in fattening beef cattle: serology and associated haematological findings

Toxoplasmosis, caused by the protozoan parasite Toxoplasma gondii, is a globally distributed zoonotic infection with significant implications for human and animal health. This study investigated the prevalence of T. gondii infection in a population of beef cattle at three different stages of their productive lifespan and examined the impact of T. gondii serological status on blood parameters. A commercial beef fattening unit in Italy was the setting for this research, which involved a biosecurity assessment upon cattle arrival, blood sampling at three time points and Toxoplasma-specific serological testing using indirect fluorescent antibody tests (IFAT). Results revealed a dynamic pattern of T. gondii seropositivity in cattle, with an initial prevalence of 30.6% at arrival (T0) that increased to 44.6% at 14 days (T1) and then decreased slightly to 39.3% at slaughter after 5 months (T2). Interestingly, seroconversion was observed during the study, indicating ongoing infections, and antibody waning occurred in some animals. In terms of blood parameters, seropositive cattle exhibited significantly lower mean corpuscular volume (MCV) and a higher neutrophil-lymphocyte (N/L) ratio, suggesting an activation of the innate immune response. Furthermore, cattle with higher antibody titres displayed higher neutrophil counts. However, all blood parameters with a statistical significance were within the reference range. This study provides for the first time a longitudinal investigation on the serological status for T. gondii in naturally exposed beef cattle. These findings provide valuable insights into the clinico-pathological aspects of natural T. gondii exposure in cattle and underscore the importance of monitoring and managing T. gondii infection in livestock production systems.