Unilateral Toxoplasma retinochoroiditis with frosted branch angiitis: a multimodal imaging study.

A woman in her late 30s presented with sudden diminution of vision, redness and pain in the right eye (OD) of 10 days' duration. Best corrected visual acuity (BCVA) was 20/160 in OD and 20/20 in the left eye (OS). Anterior segment of OD showed keratic precipitates, flare 3+, cells 2+ and a festooned pupil. Vitreous haze and cells were seen in OD. Frosted branch angiitis (FBA) was seen in all quadrants in OD and old Toxoplasma scar was seen in both eyes. Serum toxoplasma immunoglobulin G (IgG) was positive and IgM negative, and PCR of an aqueous humour sample was negative for Toxoplasma She was diagnosed with toxoplasa retinochoroiditis in OD and treated with intravitreal clindamycin injections, oral anti-Toxoplasma antibiotics and steroids. Three months later, her BCVA in OD was 20/40 with resolving inflammation. She presented 2 months later with a new focus of retinochoroiditis without FBA and an old Toxoplasma scar.

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.

Molecular detection of Toxoplasma gondii and Neospora caninum in seabirds collected along the coast of Santa Catarina, Brazil.

Toxoplasma gondii and Neospora caninum are two closely related protozoans that infect a wide range of animals, including birds. However, the occurrence of N. caninum and T. gondii in seabirds is unknown. Therefore, this study aimed to determine the presence of T. gondii and N. caninum DNA in tissue samples of seabirds. Tissue samples of the pectoral muscles, heart, and brain were collected from 47 birds along the coastline of Santa Catarina State, SC, Brazil. The DNA was extracted from the tissues and screened using nested-PCR (nPCR) targeting internal transcribed spacer 1 (ITS1). T. gondii DNA was detected in tissues from seven seabirds (7/47, 14.8%), kelp gull (Larus dominicanus) (5/21), and Manx shearwater (Puffinus puffinus) (2/8). N. caninum DNA was detected in tissues of nine seabirds (9/47, 19.1%), the kelp gull (L. dominicanus) (4/21), Manx shearwater (P. puffinus) (2/8), neotropic cormorant (Phalacrocorax brasilianus) (1/4), brown booby (Sula leucogaster) (1/5), and white-chinned petrel (Procellaria aequinoctialis) (1/1); however, no co-infection was observed. In conclusion, this study showed the circulation of N. caninum and T. gondii in seabirds along the coastline of Santa Catarina State. Further studies are required to clarify the role of these birds in the epidemiology of neosporosis and toxoplasmosis.

Is GRA6 Gene a Suitable Marker for Molecular Typing of Toxoplasma Gondii? A Scoping Systematic Review.

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

Genotyping of Toxoplasma gondii in domestic animals from Campeche, México, reveals virulent genotypes and a recombinant ROP5 allele.

Toxoplasma gondii has at least 318 genotypes distributed worldwide, and tropical regions usually have greater genetic diversity. Campeche is a state located in the southeastern region of México and has favourable climate conditions for the replication and dissemination of this protozoan, similar to those in South American countries where broad genetic diversity has been described. Thus, in this study, 4 T. gondii isolates were obtained from tissues of stray dogs and free-range chickens in Campeche, México, and were genotyped by Mn-PCR-RFLP with 10 typing markers (SAG1, altSAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1 and Apico) and 5 virulence markers (CS3, ROP16, ROP17, ROP18 and ROP5) to provide new information about the distribution and virulence prediction of T. gondii genotypes. Two isolates of T. gondii genotype #116 and 2 of genotype #38 were obtained from stray dogs and chickens, respectively. The parasite load found in these species was between <50 and more than 35 000 tachyzoites per mg of tissue. Virulence marker genotyping revealed a recombinant 1&3 ROP5 RFLP pattern in 2 ToxoDB #116 isolates with no prediction of virulence in a murine model, while in the 2 ToxoDB #38 isolates, the ROP18/ROP5 combination predicted high virulence. Considering all the typed markers, there is a predominance of type I and III alleles, as constantly reported for the isolates characterized in various regions of México. It is crucial to determine their phenotype to corroborate the genetic virulence profile of the T. gondii isolates obtained in this study.

OUTCOMES OF INFECTIOUS PANUVEITIS ASSOCIATED WITH SIMULTANEOUS MULTI-POSITIVE OCULAR FLUID POLYMERASE CHAIN REACTION.

PURPOSE: To evaluate features of infectious panuveitis associated with multiple pathogens detected by ocular fluid sampling. METHODS: Single-center, retrospective, consecutive case series of patients with aqueous/vitreous polymerase chain reaction testing with >1 positive result in a single sample from 2001 to 2021. RESULTS: Of 1,588 polymerase chain reaction samples, 28 (1.76%) were positive for two pathogens. Most common pathogens were cytomegalovirus (n = 16, 57.1%) and Epstein-Barr virus (n = 13, 46.4%), followed by varicella zoster virus (n = 8, 28.6%), Toxoplasma gondii (n = 6, 21.4%), herpes simplex virus 2 (n = 6, 21.4%), herpes simplex virus 1 (n = 6, 21.4%), and Toxocara (n = 1, 3.6%). Mean initial and final visual acuity (logarithm of the minimum angle of resolution) were 1.3 ± 0.9 (Snellen ∼20/400) and 1.3 ± 1.1 (Snellen ∼20/400), respectively. Cytomegalovirus-positive eyes (n = 16, 61.5%) had a mean final visual acuity of 0.94 ± 1.1 (Snellen ∼20/175), whereas cytomegalovirus-negative eyes (n = 10, 38%) had a final visual acuity of 1.82 ± 1.0 (Snellen ∼20/1,320) ( P < 0.05). Main clinical features included intraocular inflammation (100%), retinal whitening (84.6%), immunosuppression (65.4%), retinal hemorrhage (38.5%), and retinal detachment (34.6%). CONCLUSION: Cytomegalovirus or Epstein-Barr virus were common unique pathogens identified in multi-PCR-positive samples. Most patients with co-infection were immunosuppressed with a high rate of retinal detachment and poor final visual acuity. Cytomegalovirus-positive eyes had better visual outcomes compared with cytomegalovirus-negative eyes.

ABORTION AND NEONATAL MORTALITY DUE TO TOXOPLASMA GONDII IN BIGHORN SHEEP (OVIS CANADENSIS).

Low lamb recruitment can be an obstacle to bighorn sheep (Ovis canadensis) conservation and restoration. Causes of abortion and neonate loss in bighorn sheep, which may affect recruitment, are poorly understood. Toxoplasma gondii is a major cause of abortion and stillbirth in domestic small ruminants worldwide, but no reports exist documenting abortion or neonatal death in bighorn sheep attributable to toxoplasmosis. Between March 2019 and May 2021, eight fetal and neonatal bighorn lamb cadavers from four western US states (Idaho, Montana, Nebraska, and Washington) were submitted to the Washington Animal Disease Diagnostic Laboratory for postmortem examination, histologic examination, and ancillary testing to determine the cause of abortion or neonatal death. Necrotizing encephalitis characteristic of toxoplasmosis was identified histologically in six of eight cases, and T. gondii infection was confirmed by PCR in five cases with characteristic lesions. Other lesions attributable to toxoplasmosis were pneumonia (3/5 cases) and myocarditis (2/5 cases). Protozoal cysts were identified histologically within brain, lung, heart, skeletal muscle, adipose tissue, or a combination of samples in all five sheep with PCR-confirmed T. gondii infections. Seroprevalence of T. gondii ranged from 40-81% of adult females sampled in the Washington population in October and November 2018-2021, confirming high rates of exposure before detection of Toxoplasma abortions in this study. Of 1,149 bighorn sheep postmortem samples submitted to Washington Animal Disease Diagnostic Laboratory between January 2000 and May 2021, 21 of which were from fetuses or neonates, a single case of chronic toxoplasmosis was diagnosed in one adult ewe. Recent identification of Toxoplasma abortions in bighorn sheep suggests that toxoplasmosis is an underappreciated cause of reproductive loss. Abortions and neonatal mortalities should be investigated through postmortem and histologic examination, particularly in herds that are chronically small, demographically stagnant, or exhibit reproductive rates lower than expected.

The involvement of protozoan parasites in sheep abortions - A ten-year review of diagnostic results.

Abortions in sheep flocks affect animal health and lead to significant losses in productivity, with severe economic consequences. In recent years, the role of protozoan parasites as the cause of ovine abortions has been significant. Here, the diagnosis of infectious causes of abortions in sheep in Israel in the last decade is reviewed, focusing on parasitic pathogens. Analysis of the serological data of sheep sera (including aborted fetuses) submitted for diagnoses between 2010 and 2019 revealed overall seroprevalence of 67.4 % and 46.7 % for Neospora spp. and Toxoplasma gondii respectively, with high rates of co-exposure (32.4 %). The seroprevalence of T. gondii was higher in aborting ewes than in pre-sale examinations (48.2 % and 28.9 %, respectively (P < 0.001)). The seroprevalence of Neospora spp. was significantly higher than the seroprevalence of Toxoplasma (P < 0.001), and was similar in samples from aborting ewes and in samples from pre-sale examinations. In addition, the presence of anti-Neospora spp. antibodies was the most prominent finding diagnosed in aborted fetuses (22.9 % of aborted fetuses, significantly higher than any other organism, P < 0.001). The results of this study demonstrate that in endemic areas the seroprevalence of N. caninum in sheep may be high, and should be considered as an important cause of abortions. However, since the seroprevalence is high even in non-aborting ewes, in order to determine the causative agent of abortion in endemic flocks, a comprehensive epidemiological investigation is warranted.

Posterior segment findings by spectral-domain optical coherence tomography and clinical associations in active toxoplasmic retinochoroiditis.

Toxoplasmic retinochoroiditis is a common, potentially blinding parasitic infection. We sought to define the spectrum and frequency of signs of active toxoplasmic retinochoroiditis by spectral domain optical coherence tomography (SD-OCT), and to identify clinical associations. Ninety eyes of 90 individuals presenting consecutively to a tertiary referral uveitis service with active toxoplasmic retinochoroiditis and gradable SD-OCT scans were evaluated prospectively. SD-OCT features were collated, and associations with lesion location, primary versus recurrent episode, serological status, human immunodeficiency virus infection and best-corrected Snellen visual acuity were explored. Active toxoplasmic retinochoroiditis presented with thickened (65%) and hyperreflective (61%) retina, choroidal thickening (55%) and hyporeflectivity (61%), hyperreflective vitreous dots (80%) and deposits (36%), and posterior hyaloid thickening (35%) on SD-OCT. Most signs occurred with similar frequency across clinical groups. Retinal hyporeflectivity (17%) was significantly associated with a visual acuity of 20/200 or worse at resolution. Our observations demonstrate that active toxoplasmic retinochoroiditis has diverse SD-OCT signs and that none are universally present. Retinal hyporeflectivity-suggesting liquefactive necrosis-predicts poor visual outcome.

Retrospective study of toxoplasmosis prevalence in pregnant women in Benin and its relation with malaria.

BACKGROUND: Globally distributed with variable prevalence depending on geography, toxoplasmosis is a zoonosis caused by an obligate intracellular protozoan parasite, Toxoplasma gondii. This disease is usually benign but poses a risk for immunocompromised people and for newborns of mothers with a primary infection during pregnancy because of the risk of congenital toxoplasmosis (CT). CT can cause severe damage to fetuses-newborns. To our knowledge, no study has been conducted in sub-Saharan Africa on toxoplasmosis seroprevalence, seroconversion and CT in a large longitudinal cohort and furthermore, no observation has been made of potential relationships with malaria. METHODS: We performed a retrospective toxoplasmosis serological study using available samples from a large cohort of 1,037 pregnant women who were enrolled in a malaria follow-up during the 2008-2010 period in a rural area in Benin. We also used some existing data to investigate potential relationships between the maternal toxoplasmosis serological status and recorded malaria infections. RESULTS: Toxoplasmosis seroprevalence, seroconversion and CT rates were 52.6%, 3.4% and 0.2%, respectively, reflecting the population situation of toxoplasmosis, without targeted medical intervention. The education level influences the toxoplasmosis serological status of women, with women with little or no formal education have greater immunity than others. Surprisingly, toxoplasmosis seropositive pregnant women tended to present lower malaria infection during pregnancy (number) or at delivery (presence) and to have lower IgG levels to Plasmodium falciparum Apical Membrane Antigen 1, compared to toxoplasmosis seronegative women. CONCLUSIONS: The high toxoplasmosis seroprevalence indicates that prevention against this parasite remains important to deploy and must be accessible and understandable to and for all individuals (educated and non-educated). A potential protective role against malaria conferred by a preexisting toxoplasmosis infection needs to be explored more precisely to examine the environmental, parasitic and/or immune aspects.

Prevalence and isolation of Toxoplasma gondii in goats slaughtered for human consumption in the semi-arid of northeastern Brazil.

The aim of this study was to determine the seroprevalence of anti-Toxoplasma gondii antibodies and factors associated with infection in goats, and to isolate protozoan strains in tissue samples from seropositive goats that were destined for human consumption in the state of Paraíba, northeastern Brazil. Serum samples from 229 slaughtered goats were tested using the indirect fluorescence antibody test (IFAT), with a cutoff point of 1:64. Epidemiological questionnaires were applied to the producers, to acquire information about the sanitary management used in their herds. Tissue samples from the animals were collected during slaughter, in order to perform bioassays in mice. The seroprevalence found was 21.39% (49/229), with antibody titers ranging from 1:64 to 1:32,768. The municipalities of origin, Patos (OR: 3.047; CI: 1.384-6.706) and Sousa (OR: 3.355; CI: 1.536-7.327), were considered to be factors associated with infection by T. gondii. Thirty-eight bioassays were performed in mice, using tissues from seropositive goats, with an isolation rate of 50% (19/38). There was no correlation between isolation rate and antibody titers. Only one mouse died, at 30 days post-infection, which demonstrated that the strains isolated had low virulence towards mice. It was concluded that there is high seroprevalence in goats in northeastern Brazil, as well as a high percentage of viable tissue cysts in slaughtered animals destined for human consumption. These results demonstrate that there is an imminent one health problem relating to toxoplasmosis, especially in the most populous municipalities in the study (Patos and Sousa), which were identified as factors associated with T. gondii infection in goats.

Molecular detection of Toxoplasma gondii in placentas of women who received therapy during gestation in a toxoplasmosis outbreak.

Toxoplasmosis is a disease caused by T. gondii, a protozoa which affects humans and animals and is widely distributed worldwide. In humans, there is great concern due to the serious consequences that can occur in the infection of pregnant women and the newborn. The early diagnosis of gestational toxoplasmosis is important for treatment to be carried out in order to prevent vertical transmission or reduce damage. The diagnosis can be made through the detection of antibodies in pregnant women or neonates and PCR of amniotic fluid. Previous studies have also reported PCR of the placenta as a good diagnostic test. Our study evaluated the detection of T. gondii DNA in placenta samples from parturients seen at the University Hospital of Santa Maria, Southern Brazil and treated during the pregnancy. We performed PCR in forty samples and five were positive, representing 12.5%. When correlating the treatment time and the detection of DNA in the placentas, no significant result was found. The prevalence of positive samples was lower than in other studies in the literature. The data reaffirm the importance of carrying out the analysis of the placenta.

Acute exacerbation of pulmonary toxoplasmosis during corticosteroid therapy for immune thrombocytopenia: A case report and literature review.

RATIONALE: Pulmonary toxoplasmosis (PT) is an infectious disease that can be fatal if reactivation occurs in the recipients of hematopoietic stem cell transplantation (HSCT) who were previously infected with Toxoplasma gondii. However, whether the toxoplasmosis reactivation is an actual risk factor for patients receiving immunosuppressive therapies without HSCT remains unclear. Therefore, reactivated PT is not typically considered as a differential diagnosis for pneumonia other than in patients with HSCT or human immunodeficiency virus (HIV). PATIENT CONCERNS: A 77-year-old man presented with fever and nonproductive cough for several days. He was hospitalized due to atypical pneumonia that worsened immediately despite antibiotic therapy. Before 4 months, he was diagnosed with immune thrombocytopenia (ITP) and received corticosteroid therapy. Trimethoprim-sulfamethoxazole (ST) was administered to prevent pneumocystis pneumonia resulting from corticosteroid therapy. DIAGNOSIS: The serological and culture test results were negative for all pathogens except T. gondii immunoglobulin G antibody. Polymerase chain reaction, which can detect T. gondii from frozen bronchoalveolar lavage fluid, showed positive results. Therefore, he was diagnosed with PT. INTERVENTION: ST, clindamycin, and azithromycin were administered. Pyrimethamine and sulfadiazine could not be administered because his general condition significantly worsened at the time of polymerase chain reaction (PCR) examination. OUTCOMES: The patient died of acute respiratory distress syndrome despite anti-T. gondii treatment. An autopsy revealed a severe organizing pneumonia and a small area of bronchopneumonia. LESSONS: PT should be considered as a differential diagnosis in patients with pneumonia, particularly in seropositive patients who receive immunosuppressive therapies even for other than HSCT or HIV.

Detection of Pneumocystis jirovecii and Toxoplasma gondii in patients with lung infections by a duplex qPCR assay.

Pneumocystis pneumonia (PCP) and pulmonary toxoplasmosis (PT) are caused by Pneumocystis jirovecii and Toxoplasma gondii. The clinical symptoms and imaging of PCP and PT are indistinguishable. A duplex qPCR was developed to differentiate between these two pathogens. In testing 92 clinical samples to validate the performance of this method for P. jirovecii detection, it identified 31 positive samples for P. jirovecii infection, consistent with clinical diagnosis. Among the remainder of the 61 clinical samples with suspected PCP, yet showing as negative by the conventional PCR diagnosis approach, 6 of them proved positive using our new assay. Our new approach also produced similar results in identification of T. gondii infections, giving a result of 2 positive and 20 negative in clinical samples. An investigation was undertaken on the prevalence of P. jirovecii and T. gondii infections using 113 samples from lung infection patients. 9% (10/113) were shown to be positive with infections of P. jirovecii, 2% with T. gondii (2/113) and 5% (6/113) were co-infected with both pathogens. Although this duplex qPCR can detect individual P. jirovecii and T. gondii infection, and co-infection of both pathogens, further large-scale investigations are needed to validate its performance, especially in T. gondii detection. Our assay provides a rapid and accurate tool for PCP and PT diagnosis in immunocompromised population and clinical surveillance of these infections in patients with no immune defects.

Detection of toxoplasmosis in pets and stray cats through molecular and serological techniques in Khyber Pakhtunkhwa, Pakistan.

BACKGROUND: Toxoplasma gondii is an important parasite that belongs to the phylum Apicomplexa, distributed globally, causing major health issues for a wide range of hosts, including humans, native and wild animals. METHODS: In the present study, we detected IgG and IgM antibodies through an ELISA kit and DNA of T. gondii through PCR in 197 pets and stray cats in Peshawar, Charsadda, Mardan, and Kohat districts of Khyber Pakhtunkhwa (Pakistan) to estimate the existence of feline toxoplasmosis. RESULTS: The current study revealed that stray cats have a significant infection rate of T. gondii (74.6%) as compared to pet cats (25.4%). In all the four districts, the prevalence of T. gondii was pointedly higher in district Kohat (95.5%) in the feline population. In comparison to the female (75.18%) and male (both pets and stray) cats have a maximum infection of (81.66%) non-significantly. The prevalence of T. gondii was observed to be significantly higher (91.66%) in the older and greater than 4 year old population of cats as compared to the younger ones. In poor health condition, the cat populations has a higher risk of infection of 92.3% as compared to healthy and poor body condition (73.91%) and (82.6%) respectively. The chronic and reactivated chronic conditions of toxoplasmosis were higher (58.37%) as compared to the acute condition. CONCLUSION: It has been concluded that toxoplasmosis is widely spread in the studied population.The outcomes of the present study show that T. gondii infection has a significant impact on the type of cat, age, and area, which implies a serious threat to human beings. Therefore, genotyping of T. gondii strains from different hosts is needed to forecast the current approach for prevention and control of this zoonotic parasite.

Cross-sectional association of Toxoplasma gondii exposure with BMI and diet in US adults.

Toxoplasmosis gondii exposure has been linked to increased impulsivity and risky behaviors, which has implications for eating behavior. Impulsivity and risk tolerance is known to be related with worse diets and a higher chance of obesity. There is little known, however, about the independent link between Toxoplasma gondii (T. gondii) exposure and diet-related outcomes. Using linear and quantile regression, we estimated the relationship between T. gondii exposure and BMI, total energy intake (kcal), and diet quality as measured by the Health Eating Index-2015 (HEI) among 9,853 adults from the 2009-2014 National Health and Nutrition Examination Survey. Previous studies have shown different behavioral responses to T. gondii infection among males and females, and socioeconomic factors are also likely to be important as both T. gondii and poor diet are more prevalent among U.S. populations in poverty. We therefore measured the associations between T. gondii and diet-related outcomes separately for men and women and for respondents in poverty. Among females <200% of the federal poverty level Toxoplasmosis gondii exposure was associated with a higher BMI by 2.0 units (95% CI [0.22, 3.83]) at median BMI and a lower HEI by 5.05 units (95% CI [-7.87, -2.24]) at the 25th percentile of HEI. Stronger associations were found at higher levels of BMI and worse diet quality among females. No associations were found among males. Through a detailed investigation of mechanisms, we were able to rule out T. gondii exposure from cat ownership, differing amounts of meat, and drinking water source as potential confounding factors; environmental exposure to T. gondii as well as changes in human behavior due to parasitic infection remain primary mechanisms.

Presence of atypical genotypes of Toxoplasma gondii isolated from cats in the state of Bahia, Northeast of Brazil.

In this study, 20 blood, heart, and brain samples were collected from euthanized cats at the Zoonosis Control Centers and Veterinary Clinics in the state of Bahia, Brazil. The sera were examined for anti-T. gondii antibodies using the indirect hemagglutination test. The brains and hearts of seven seropositive cats were ground, and peptide digestion was performed for bioassay in mice. Toxoplasma gondii was isolated in 5/7 (71.42%) of seropositive cats. In these isolates, the parasite was genotyped using the Polymerase chain reaction, associated with the DNA fragment polymorphism obtained by restriction enzyme PCR-RFLP technique with 11 markers (SAG1, 5'-SAG2, 3'-SAG2, alt. SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, Apico, and CS3) and 15 microsatellite markers (TUB-2, W35, TgM-A, B18, B17, M33, IV.1, XI.1, M48, M102, N60, N82, AA, N61, N83). The analysis of the isolates by PCR-RFLP revealed five distinct genotypes. Three of these genotypes have never been reported before; one corresponded to the TgDgCo13 genotype, and one incomplete genotype. In genotyping analysis using microsatellite markers, it was observed that the isolates showed atypical alleles in the typing and fingerprint markers. This revealed five atypical genotypes. The typing marker B17 showed the highest degree of atypia. This study is the first to report the genotyping of T. gondii obtained from naturally infected cats in Bahia, Northeast Brazil. The genotypes found in this study were different from those found in other studies conducted in Bahia, which included different species of animals. None of the clonal lineages I, II, or III were found. This study demonstrates the diversity of T. gondii in the study region, with the presence of unusual genotypes, reaffirming the genetic variability of the parasite in Brazil.

Toxoplasma gondii Tyrosine-Rich Oocyst Wall Protein: A Closer Look through an In Silico Prism.

Toxoplasmosis is a global threat with significant zoonotic concern. The present in silico study was aimed at determination of bioinformatics features and immunogenic epitopes of a tyrosine-rich oocyst wall protein (TrOWP) of Toxoplasma gondii. After retrieving the amino acid sequence from UniProt database, several parameters were predicted including antigenicity, allergenicity, solubility and physico-chemical features, signal peptide, transmembrane domain, and posttranslational modifications. Following secondary and tertiary structure prediction, the 3D model was refined, and immunogenic epitopes were forecasted. It was a 25.57 kDa hydrophilic molecule with 236 residues, a signal peptide, and significant antigenicity scores. Moreover, several linear and conformational B-cell epitopes were present. Also, potential mouse and human cytotoxic T-lymphocyte (CTL) and helper T-lymphocyte (HTL) epitopes were predicted in the sequence. The findings of the present in silico study are promising as they render beneficial characteristics of TrOWP to be included in future vaccination experiments.

High prevalence of anti-Toxoplasma gondii antibodies in beef cattle in Midwestern Brazil.

The present study aimed to determine the seroprevalence of anti-Toxoplasma gondii antibodies using an indirect immunofluorescence assay (IFA-IgG) in 3,814 cows aged ≥ 24 months belonging to 353 beef farms in the Mato Grosso state. Additionally, we aimed to identify the possible risk factors associated with seropositivity in Mato Grosso, which encompasses three biomes (Amazon, Cerrado, and Pantanal) of Brazil. Analysis of 3,814 samples observed that 1,307 animals were positive for anti-T. gondii antibodies (IFA-IgG ≥ 64), with an animal-level seroprevalence of 34.27%. Herd-level seroprevalence was 92.07%. In the animal-level model, cows raised in the Amazon and Pantanal biomes and breed studies on European and Zebu or hybrid were found to be at risk for T. gondii seropositivity. Prevalence of anti-T. gondii antibodies in cows destined for human consumption was found to be widely distributed throughout the entire study area. Further studies are required to assess the impact of beef in the possible transmission of toxoplasmosis to humans residing in the region and establish additional control measures for this protozoan mainly on beef herds raised in the Amazon and Pantanal biomes, where the highest values of seroprevalence were observed.