Severity Of Toxoplasmosis Research Articles

Gut microbiota-related metabolite alpha-linolenic acid mitigates intestinal inflammation induced by oral infection with Toxoplasma gondii

BackgroundOral infection with cysts is the main transmission route of Toxoplasma gondii (T. gondii), which leads to lethal intestinal inflammation. It has been widely recognized that T. gondii infection alters the composition and metabolism of the gut microbiota, thereby affecting the progression of toxoplasmosis. However, the potential mechanisms remain unclear. In our previous study, there was a decrease in the severity of toxoplasmosis after T. gondii α-amylase (α-AMY) was knocked out. Here, we established mouse models of ME49 and Δα-amy cyst infection and then took advantage of 16S rRNA gene sequencing and metabolomics analysis to identify specific gut microbiota-related metabolites that mitigate T. gondii-induced intestinal inflammation and analyzed the underlying mechanism.ResultsThere were significant differences in the intestinal inflammation between ME49 cyst- and Δα-amy cyst-infected mice, and transferring feces from mice infected with Δα-amy cysts into antibiotic-treated mice mitigated colitis caused by T. gondii infection. 16S rRNA gene sequencing showed that the relative abundances of gut bacteria, such as Lactobacillus and Bacteroides, Bifidobacterium, [Prevotella], Paraprevotella and Macellibacteroides, were enriched in mice challenged with Δα-amy cysts. Spearman correlation analysis between gut microbiota and metabolites indicated that some fatty acids, including azelaic acid, suberic acid, alpha-linolenic acid (ALA), and citramalic acid, were highly positively correlated with the identified bacterial genera. Both oral administration of ALA and fecal microbiota transplantation (FMT) decreased the expression of pro-inflammatory cytokines and restrained the MyD88/NF-κB pathway, which mitigated colitis and ultimately improved host survival. Furthermore, transferring feces from mice treated with ALA reshaped the colonization of beneficial bacteria, such as Enterobacteriaceae, Proteobacteria, Shigella, Lactobacillus, and Enterococcus.ConclusionsThe present findings demonstrate that the host gut microbiota is closely associated with the severity of T. gondii infection. We provide the first evidence that ALA can alleviate T. gondii-induced colitis by improving the dysregulation of the host gut microbiota and suppressing the production of pro-inflammatory cytokines via the MyD88/NF-κB pathway. Our study provides new insight into the medical application of ALA for the treatment of lethal intestinal inflammation caused by Toxoplasma infection.5uvpHNDACknu2usY1bpcjuVideo

Development of a new serotyping ELISA for Toxoplasma gondii type II, type III and Africa 1 lineages using in silico peptide discovery methods, well categorized feline and human outbreak serum samples

BackgroundDiscovery of new Toxoplasma gondii serotyping epitopes is important due to reports showing the influence of genotype on the severity of toxoplasmosis. In Turkey, genotypes belonging to type II, type III and Africa 1 lineages were mainly detected. The present study focused on to find out epitopes with high discriminative capacity to serotype these genotypes using well characterized strains isolated from Turkey.MethodsTo meet this objective, GRA6 and GRA7 genes were sequenced from strains belonging to the type II, III and Africa 1 lineages, and B cell epitopes inside these sequences were predicted by Bcepred and additional docking analysis was performed with B cell receptor. Based on these analyses, 22 peptides harboring lineage specific epitopes were synthesized. Then, the serotyping potency of these peptides was tested using peptide ELISA and well categorized serum samples collected from stray cats infected with genotypes of the different lineages type II (n:9), III (n:1) and Africa 1 (n:1). As a result of peptide-ELISA, a serotyping schema was constructed with peptides that show high discriminative capacity and this assay was validated by sera collected from humans after an outbreak (n:30) and mother/newborn pair sera (n:3). Later, the validated serotyping schema was used to serotype a larger group of human (n:38) and cat (n:24) sera.ResultsAmong 22 peptides, GRA6II/c, GRA7III/d, and GRA6 Africa 1/b epitopes have shown discriminative capacity. During the validation of peptide-ELISA, the serotype of toxoplasmosis outbreak and mother/newborn cases were detected to be serotype II. Moreover, the analyses in a larger group showed that serotype II was prevalent in humans and stray cats.ConclusionsOverall, the results showed that the serotyping schema could be successfully used to serotype T. gondii infections caused by type II, III and Africa 1 genotype.

The Severity of Malaria and Toxoplasmosis Co-Infections among Pregnant Women in Yaounde, Cameroon

Malaria and toxoplasmosis are two diseases caused by parasites of the same phylum (Apicomplexa). They have severe consequences on the health of pregnant women and their unborn babies. As such, they are of importance for the public health, especially in Sub-Saharan Africa and Cameroon. The aim of this study was to evaluate the severity of toxoplasmosis among malaria-positive pregnant women attending the Biyam-Assi District Hospital. It was a cross-sectional study that took place from May to November 2019 involving 232 pregnant women who voluntarily accepted to take part in the study. Demographic data was collected using structured questionnaires and blood was collectd by finger prick. Thick blood films were prepared for the detection of malaria and the Giemsa-stained slides were read microscopically. A drop of blood was used for the detection of toxoplasmosis using the chromatographic cassette (Rapid Diagnostic Test) and the results were read after 15 minutes. The data obtained was analysed using SPSS version 24. The results showed that the prevalence of toxoplasmosis was 22.84 %. This prevalence didn’t depend on the trimester of pregnancy (P = 0. 08). The prevalence of malaria was 38.9%. No significant difference was observed for either the prevalence or severity of malaria over the three trimesters of pregnancy (p = 0.60 and p = 0.9 respectively). The prevalence of co-infection with malaria and toxoplasmosis was 9.05%. Women without toxoplasmosis were more prone to severe malaria (20.29 %) than their counterparts who had toxoplasmosis (4.78 %) and the difference between these two groups was statistically significant (p = 0.02). The severity of toxoplasmosis was not influenced by the presence of Plasmodium (p = 0. 20). It was concluded that the occurrence and severity of toxoplasmosis in pregnant women does not depend on their malaria serological status. However, the presence of severe malaria in pregnant women depends on their toxoplasmosis status. Indeed, women already infected with T. gondii are less susceptible to malaria than their counterparts who are negative for toxoplasmosis. These findings suggest that T. gondii in a person confers some form of reistance to infections with Plasmodium. It was recommended that the Public Health Ministry in Cameroon could include screening for toxoplasmosis among the routine test for pregnant women in order to improve on the health of mother and baby.

Stray dogs in the tropical state of Chiapas, Mexico, harbour atypical and novel genotypes of Toxoplasma gondii

Genotyping of Toxoplasma gondii remains a relevant topic of study, since genotypes can be related to the presentation and severity of toxoplasmosis. To date, 292 restriction fragment length polymorphism genotypes have been described around the world. Serosurveys in southeastern Mexico have documented exposure in over 70% of people and certain animals. Recently, we have described new genotypes and mixed infections in feral cats from Quintana Roo. Thus, the aim of this study was to genotype T. gondii and to describe its genetic variability, from naturally infected stray dogs of Chiapas, which has different geographical and climatic conditions from those found at the Yucatan Peninsula and the other parts of the country. Eleven stray dogs were captured and bled to obtain DNA, and then they were euthanized to perform necropsies and to collect target tissues. Diagnosis of T. gondii was done by quantitative real-time PCR (qPCR) and endpoint PCR. Genotyping was carried out, amplifying 12 polymorphic markers and 15 microsatellites. Atypical SAG3 gene products were cloned and sequenced. All blood samples of dogs were positive to T. gondii DNA by PCR. Two isolates were obtained from pooled heart and diaphragm tissue of two dogs. Two complete PCR-RFLP genotypes were identified (type BrIII and #28). Four animals had mixed infections. A new RFLP atypical allele for the SAG3 marker was observed; cloning and sequencing analysis of this locus revealed mixed infection by a strain identical to GT1, and one type I × II intragenic recombinant. The microsatellite analysis revealed that both isolates are atypical. Thus, atypical new genotypes of T. gondii and mixed infections were found in dogs of Chiapas. The results found here and in genotyping studies in México suggest that the southeastern region favours wide genetic diversity of T. gondii and the possible presence of virulent genotypes such as those found in central and South America.

Mixed Toxoplasma gondii infection and new genotypes in feral cats of Quintana Roo, México

Toxoplasmosis is a zoonosis caused by Toxoplasma gondii that infects homeothermic animals, including humans. To date, as many as 287 genotypes have been described worldwide. Genetic characterization of the parasite is crucial because the parasite type can determine the presentation and severity of toxoplasmosis. Previously, we reported that the Yucatán Peninsula has a frequency of infection of over 70% in humans and other animals; moreover, there are seven species of felids, including domestic cats; thus, we hypothesized that this might be a region with a high diversity of the parasite. Nevertheless, no genotyping of this protozoan has been performed in this region. Thus, the aim of this study was to genotype T. gondii from naturally infected feral cats of Quintana Roo, within the Yucatán Peninsula, and to describe its genetic variability. Eleven feral cats were captured and bled to obtain the buffy coat; then, they were euthanized to collect target organs or tissues to extract DNA. Samples were processed by PCR for diagnosis, and ten polymorphic markers were genotyped by PCR-RFLP. Atypical GRA6 gene products were cloned and sequenced. Ten of the eleven cats were PCR positive for toxoplasmosis in blood; of these, seven had mixed infections. Also, two isolates were obtained from the heart and diaphragm of two animals. At least 23 different genotypes were detected, from which 18 are new worldwide. From the atypical GRA6 gene cloning and sequencing analysis, a mixed infection was discovered, due to one strain identical to GT1 and another to VAND. In conclusion, T. gondii genetic diversity in the region is high and different from that in other regions, with new genotypes exclusive to México and some others shared with USA and South America.

Behavioral Abnormalities in a Mouse Model of Chronic Toxoplasmosis Are Associated with MAG1 Antibody Levels and Cyst Burden.

There is marked variation in the human response to Toxoplasma gondii infection. Epidemiological studies indicate associations between strain virulence and severity of toxoplasmosis. Animal studies on the pathogenic effect of chronic infection focused on relatively avirulent strains (e.g. type II) because they can easily establish latent infections in mice, defined by the presence of bradyzoite-containing cysts. To provide insight into virulent strain-related severity of human toxoplasmosis, we established a chronic model of the virulent type I strain using outbred mice. We found that type I-exposed mice displayed variable outcomes ranging from aborted to severe infections. According to antibody profiles, we found that most of mice generated antibodies against T. gondii organism but varied greatly in the production of antibodies against matrix antigen MAG1. There was a strong correlation between MAG1 antibody level and brain cyst burden in chronically infected mice (r = 0.82, p = 0.0021). We found that mice with high MAG1 antibody level displayed lower weight, behavioral changes, altered levels of gene expression and immune activation. The most striking change in behavior we discovered was a blunted response to amphetamine-trigged locomotor activity. The extent of most changes was directly correlated with levels of MAG1 antibody. These changes were not found in mice with less cyst burden or mice that were acutely but not chronically infected. Our finding highlights the critical role of cyst burden in a range of disease severity during chronic infection, the predictive value of MAG1 antibody level to brain cyst burden and to changes in behavior or other pathology in chronically infected mice. Our finding may have important implications for understanding the heterogeneous effects of T. gondii infections in human.

Development of Improved Preventive and Treatment Strategies for Controlling of Toxoplasmosis in Saudi Arabia

Toxoplasmosis causes severe public health problems and has great veterinary and economic importance worldwide. The present study aims mainly to develop an improved preventive and treatment program for controlling toxoplasmosis in sheep and goats. This study was performed on sheep and goats farm containing 357 animals (300 sheep and 57 goats). This farm had a large numbers of barren ewes, history of abortions (below 4 months), stillbirths, malformations and neonatal losses. Blood samples were collected to determine humeral antibody responses and prevalence of toxoplasmosis. Sections of normal and abnormal tissues were fixed using 10% buffered formalin for histopathological examination. Different and new drug regimens and strategies were used for controlling toxoplasmosis. Sixty-four out of 357 sheep and goats were clinically affected with 17.9% overall morbidity rate. These animals showed certain clinical symptoms of toxoplasmosis, such as abortions and stillbirth. The seroprevalence rate was 15.4%. The titers of ELISA were high before treatment in positive cases while after treatment the titers were decreased for certain level that continued to the end of study. The field treatment revealed that the affected sheep and goats treated with camel lactoferrin (cLf) and chemotherapy combination regimen significantly reduced the overall severity of toxoplasmosis with reduction in IgG titers better than those treated with chemotherapy alone (Pyrimethamine and sulfamethazine) or cLf alone. In conclusion, cLf and chemotherapy combination regimen was success in control of toxoplasmosis in small ruminants.

Actividad anti-Toxoplasma de extractos metanólicos de frutos y hojas de Sambucus nigra (Caprifoliaceae)

<p><em>Toxoplasma gondii </em>is an obligatory intracellular parasite that infects a wide range of warm-blooded animals and humans. Considering the severity of toxoplasmosis, side effects of current treatments, and the contribution of the ethnopharmacological knowledge for the treatment of parasitic infections, the aim of the present study was to investigate the efficacy of methanolic extracts from the fruits and leaves of <em>Sambucus nigra </em>against tachyzoite of <em>T. gondii</em>. For this, fruits and leaves of <em>S. nigra </em>were collected from Mazandaran province, Iran, were dried under the shade, and powdered using a commercial electrical blender. For extractions, methanol was used as solvent. Virulent RH strain of <em>T. gondii</em> was maintained in mice and macrophages containing tachyzoites were aspirated from the peritoneal cavity. Four concentrations (5, 10, 25 and 50mg/mL) of <em>S. nigra </em>extract were incubated with infected macrophages for 30, 60, 120 and 180 minutes and the viability of the tachyzoites were evaluated by trypan blue staining. Results showed that <em>S. nigra </em>fruit extracts at the concentrations of 5 and 10mg/mL killed 100% of <em>T. gondii</em> tachyzoites after 60 and 120 minutes, respectively; and concentrations of 25 and 50mg/mL killed 100% of the tachyzoites after 30 minutes. Additionally, extract of <em>S. nigra</em> leaves, at the concentrations of 5, 10 and 25mg/mLafter 180 minutes, and concentration of 50mg/mLafter 60 minutes, resulted with the highest efficacy. Our results showed that <em>S. nigra</em> has acceptable efficacy <em>in vitro</em> and the parasiticidal effect of fruit extract was significantly better than leaf extract. However, <em>in vivo</em> efficacy of this extract needs further investigation.</p>

Ante-Mortem Diagnosis, Diarrhea, Oocyst Shedding, Treatment, Isolation, and Genetic Typing ofToxoplasma gondiiAssociated with Clinical Toxoplasmosis in a Naturally Infected Cat

Toxoplasma gondii infections are common in humans and other animals, but clinical disease is relatively rare. It is unknown whether the severity of toxoplasmosis in immunocompetent hosts is due to the parasite strain, host variability, or to other factors. Recently, attention has been focused on the genetic variability among T. gondii isolates from apparently healthy and sick hosts. Whether T. gondii genetic makeup plays a part in the pathogenesis of clinical feline toxoplasmosis is uncertain because little is known of genetic typing of strains associated with clinical feline toxoplasmosis. A 6-mo-old domestic male cat was hospitalized because of lethargy, anorexia, fever, and diarrhea. Numerous (6 million in 1 sample) T. gondii oocysts were found in feces of the cat and antibodies to T. gondii (titer 1:800) were found in its serum by the modified agglutination test. The cat was medicated orally with Clindamycin for 10 days; it became asymptomatic after 10 days and was discharged from the hospital. Viable T. gondii (designated TgCatUs9) was isolated from feces (oocysts) by bioassays in mice. Genetic typing using the DNA extracted from the brains of infected mice and 10 PCR-restriction fragment length polymorphism (RFLP) markers revealed Type II allele at the SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, and PK1 loci and Type I at the L358 and Apico loci; therefore, this isolate belongs to the ToxoDB PCR-RFLP genotype no. 4, which is grouped into the Type 12 lineage that is dominant in wildlife from North America. To our knowledge, this is the first T. gondii isolate characterized genetically from a sick cat in the USA.

HLA-class II genes modify outcome of Toxoplasma gondii infection

Associations between Human Leukocyte Antigen (HLA) (i.e. human major histocompatibility complex [MHC]) genes and susceptibility to infections and inflammatory processes have been described, but causal relationships have not been proven. We characterized effects of HLA-DQ alleles on outcome of congenital toxoplasma infection and found that among Caucasians, the DQ3 gene frequency was significantly higher in infected infants with hydrocephalus (0.783) than infected infants without hydrocephalus (0.444) or published normal controls (0.487). We then developed a novel animal model to definitively determine the effect of these HLA DQ molecules on the severity of toxoplasmosis. Human MHC-Class II transgenes reduced parasite burden and necrosis in brains of mice infected with Toxoplasma gondii. Consistent with the observed association between DQ3 and hydrocephalus in human infants, in the murine model the DQ3(DQ8; DQB1∗0302) gene protected less than DQ1 (DQ6; DQB1∗0601). Our findings definitively prove a cause and effect relationship between human MHC genes and resistance to infection, provide novel means to characterise human immune responses that are protective or pathogenic in infections, and are important for vaccine development.