About 30-50% of the world human population are infected with the protozoan parasite Toxoplasma gondii (Nicolle et Manceaux, 1908). Latent toxoplasmosis has many specific behavioural and physiological effects on the human body and influences the course of pregnancy, including secondary sex ratio of children of infected mothers. It was suggested that an increased concentration of glucose could be the proximate cause of increased sex ratio. There are some indirect indications of possible association between toxoplasmosis and certain forms of diabetes. Here we searched for a possible link between latent toxoplasmosis and the level of glucose in the blood. In a cross-sectional study, we found that pregnant women with latent toxoplasmosis had significantly higher blood glucose levels during the oral glucose tolerance test (n = 191, p = 0.010; the level of fasting plasma glucose: mean = 5.04 mmol/l vs mean = 4.88 mmol/l; blood glucose level at 1 hour mean = 7.73 mmol/l vs mean = 6.89 mmol/l and blood glucose level at two hours mean = 6.43 mmol/l vs mean = 5.74 mmol/l) and higher prevalence (19.5 %) of gestational diabetes mellitus (n = 532, p = 0.033, odds ratio = 1.78) in the 24-28th gestational weeks than T. gondii-free women (12.0 %). Increased level of glucose and increased incidence of gestational diabetes mellitus could have considerable clinical impact as contributors to the development of the metabolic syndrome and type 2 diabetes in T. gondii-infected women. Our results also brought the first empirical support for the hypothesis that the glucose concentration may play a role in T. gondii-associated offspring sex ratio shifts., Šárka Kaňková, Jaroslav Flegr, Pavel Calda., and Obsahuje bibliografii
Toxoplasma gondii (Nicolle et Manceaux, 1908) is an obligate intracellular apicomplexan parasite and can infect warmblooded animals and humans all over the world. Development of effective vaccines is considered the only ideal way to control infection with T. gondii. However, only one live vaccine is commercially available for use in sheep and goats. Thus more effective antigenic proteins are searched for. In the present study we report a novel protein by secreted T. gondii termed Myc regulation 1 (MYR1). The physical and chemical characteristics, epitopes, hydrophilicity and functional sites of MYR1 were analysed by multiple bioinformatic approaches. The 3D models of MYR1 proteins were constructed and analysed. Furthermore, liner B-cell epitopes and T-cell epitopes of MYR1 protein and SAG1 were predicted. Compared to SAG1, MYR1 with good B-cell epitopes and T-cell epitopes had a potentiality to become a more successful vaccine against T. gondii. The bioinformatics analysis of MYR1 proteins could laid the foundation for further studies of its biological function experimentally and provide valuable information necessary for a better prevention and treatment of toxoplasmosis., Jian Zhou, Gang Lu, Shenyi He., and Obsahuje bibliografii
Toxoplasmosis is one of the world's most prevalent zoonoses. The causative agent, Toxoplasma gondii (Nicolle et Manceaux, 1908) is a facultative heteroxenic, polyxenic apicomplexan protist. There are several potential pathways of transmission within and between host species. Most infections with T. gondii result from close contact with pets/cats, ingestion of tissue cysts in undercooked meat of infected animals, and oocysts from food or water contaminated by feline faeces. Recently, epidemiological studies have shown that T. gondii infection plays a prominent role in the pathogenesis of several psychiatric disorders. This report reviews the association between T. gondii infection and patients with psychiatric disorders, particularly schizophrenia, depressive disorders and bipolar disorders.
The aim of the present study was to investigate the association between various clinical aspects of schizophrenia and seropositivity against Toxoplasma gondii (Nicolle et Manceaux, 1908). We selected 94 patients with schizophrenia and investigated the seropositivity rate for anti-T. gondii IgG antibodies by ELISA. Clinical parameters of schizophrenic patients such as illness type and status, clinical course, awareness of the illness and need for electroconvulsive therapy (ECT) were compared with their serological status. Anti-T. gondii IgG antibodies were detected in 43 (46%) of schizophrenic patients. Chronic patients had a rate of 34 (72%) seropositivity, whereas 9 (22%) of the patients with partial remission showed evidence of latent toxoplasmosis. Of continuous patients, 35 (81%) were found to be seropositive and this rate was significantly more than in the other groups. The rate of latent toxoplasmosis was detected significantly higher in patients who lack awareness of schizophrenia (36, i.e. 72%) than the patients who were aware of their illnesses (7, i.e. 16%). Anti-T. gondii IgG antibodies were detected in 38 (70%) of ECT performed patients while this percentage was 13% in the ones who had never been treated with ECT. This difference was also statistically significant. We showed that Toxoplasma-infected subjects had 15× higher probability of having continuous course of disease than Toxoplasma-free subjects. Our results put forth the possibility of latent toxoplasmosis to have a negative impact on the course of schizophrenia and treatment response of schizophrenic patients., Tuncay Çelik, Şükrü Kartalci, Özgür Aytaş, Gülay Aral Akarsu, Harika Gözükara, Süheyla Ünal., and Obsahuje bibliografii
Pulmonary pathology is common in HIV-infected individuals, but the possible role of the parasitic protist Toxoplasma gondii (Nicolle et Manceaux, 1908) is not completely known. The present account reports result of a retrospective cohort study. Medical cards of 907 HIV-positive people, which included 120 deceased patients, were analysed. During a three-year follow-up, the pulmonary pathology was diagnosed in 306 patients (33.7 ± 1.6%): pneumocystis pneumonia in 124 (13.7 ± 1.1%), primary pulmonary tuberculosis in 113 (12.5 ± 1.1%), bacterial pneumonia in 58 (6.4 ± 0.8%) toxoplasmosis pneumonia in two (0.2 ± 0.2%), and others. All patients were divided into two cohorts: 531 individuals seropositive for T. gondii and 376 seronegative ones. It has been found out that general lung pathology is more common in patients with seropositivity to T. gondii than in seronegative ones (43.3 ± 2.2% vs. 20.1 ± 2.0%, p < 0.001). The diagnosis of pneumocystis pneumonia was made ten times more often in the cohort of seropositive patients than in the cohort of seronegative ones (21.9 ± 1.8% vs. 2.1 ± 0.7%, respectively, p < 0.001) and in deceased patients of these cohorts it was 5.5 times more (45.1 ± 5.9% vs. 8.2 ± 3.9, respectively, p < 0.001). In patients with fatal outcome and seropositivity to T. gondii, the incidences of pneumocystis pneumonia increased by 23.2% (p < 0.001) and bacterial pneumonia by 12.4% (p < 0.05), whereas in seronegative individuals only pulmonary tuberculosis increased by 13.1% (p < 0.05) сompared with corresponding whole cohorts. Pearson's contingency coefficient showed the mean strength association between infection with T. gondii and incidence of pneumocystis pneumonia both in whole cohort (C = 0.272) and in patients with fatal outcomes (C = 0.368). In сonclusion, significantly increasing rate of pneumocystis pneumonia in patients with HIV/AIDS and T. gondii infection can be caused by certain synergism between T. gondii and Pneumocystis jirovecii and in some cases overdiagnosis pneumocystis pneumonia due to undiagnosed toxoplasmosis pneumonia.
Toxoplasmosis is a potentially fatal complication after hematopoietic cell transplantation (HCT). Pre-transplant seropositivity of graft recipient to Toxoplasma gondii (Nicolle et Manceaux, 1908) is an important factor for disease reactivation after HCT. As toxoplasmosis epidemiology varies all over the world, we performed a Polish nationwide retrospective cohort study to determine the seroprevalence of toxoplasmosis in donors and pediatric allogeneic and autologous HCT recipients and the incidence of clinically evident toxoplasmosis in this patient group. Polish adult donors had higher anti-T. gondii seroprevalence than Polish pediatric donors (28% vs 8%; OR = 4.4; p = 0.02) and allo-HCT recipients (28% vs 17%; OR = 1.9; p = 0.01). Clinically apparent disease occurred in 1% of allo-HCT recipients: it was diagnosed by PCR as cerebral and/or ocular toxoplasmosis and successfully treated with antiprotozoal therapy. Regarding current practice, no prospective screening for infection of T. gondii in pediatric HCT centres is being performed, but, vast majority of HCT pediatric patients are receiving anti-T. gondii active prophylaxis. Since pre-HCT T. gondii serology was not assessed in all HCT; recipients, we propose this test should be a standard practice. Standardisation of management with infection of T. gondii in children after HCT is needed.
Toxoplasmosis is a common parasitic disease caused by Toxoplasma gondii (Nicolle et Manceaux, 1908), an obligate parasite capable of infecting a range of cell types in almost all warm-blooded animals. Upon infecting an intermediate host, the parasites differentiate into tachyzoites which rapidly infect host tissues. Usually, the invading parasites are cleared by the immune system and administered drugs, but some tachyzoites differentiate into bradyzoites forming tissue cysts. These tissue cysts could serve as a source for re-infection and exacerbations. Currently, treatment for toxoplasmosis is limited and, moreover, there are no drugs for treating the cystic stage thus rendering toxoplasmosis a global burden. Recently, we demonstrated that inorganic nanoparticles showed promising activity against the tachyzoite stage T. gondii. In the present study, we evaluated nanoparticles for effect on bradyzoite formation in vitro. Data revealed that the nanoparticles limited bradyzoite burden in vitro. Further, the nanoparticles decreased the bradyzoite-specific BAG-1 promoter activity relative to the untreated control under a bradyzoite-inducing culture condition, even though this reduction in BAG-1 promoter activity waned with increasing concentrations of nanoparticles. In contrast, a parallel experiment under normal cell culture conditions showed that the nanoparticle treatment mildly increased the BAG-1 promoter activity relative to the untreated control. Taken together, the findings are evidence that nanoparticles not only possess anti-tachyzoite potential but they also have anti-bradyzoite potential in vitro., Oluyomi Stephen Adeyemi, Yuho Murata, Tatsuki Sugi, Yongmei Han, Kentaro Kato., and Obsahuje bibliografii
Toxoplasma gondii Nicolle et Manceaux, 1909, the etiologic agent of toxoplasmosis, was considered a clonal population with three distinct genetic lineages (I, II and III); however, sequence analysis of different strains has revealed distinct atypical genotypes. Macrophages are essential for immunity against toxoplasmosis and differential cell regulation may affect the course of the disease. In this context, our study aims to investigate the infection by TgChBrUD2, a highly virulent atypical Brazilian strain of T. gondii, on the activation and polarisation of human macrophages. Human macrophage-like cells obtained from THP-1 cells were infected with TgChBrUD2, RH or ME49 strains of T. gondii to evaluate the impact of parasite infection on macrophage polarisation. Our results indicate that the TgChBrUD2 and ME49 strains of T. gondii induced a classic activation of human macrophages, which was confirmed by the high rate of spindle-shaped macrophages, low amount of urea and increase in the levels of nitrite, as well as the down-regulation of M2-markers. In contrast, RH strain promoted an alternative activation of macrophages. The polarisation of human macrophages towards an M1 subtype mediated by TgChBrUD2 and ME49 strains resulted in a low parasite burden, with high levels of IL-6 and MIF. Finally, the M2 subtype triggered by the RH strain culminated in a lower intracellular proliferation index. We concluded that the atypical (TgChBrUD2) and clonal (ME49) strains are able to elicit an M1 subtype, which results in parasitism control, partially explained by the high levels of IL-6 and MIF produced during the infection by these genotypes. In contrast, the clonal (RH) strain promoted a macrophage polarisation towards an M2 subtype, marked by a high parasite burden, with a weak modulation of pro-inflammatory cytokines. Thus, atypical strains can present different mechanisms of pathogenicity and transmissibility compared to clonal strains, as well as they can use distinct strategies to evade the host's immune response and ensure their survival.
Hunting dogs have probably a higher level of exposure to Neospora caninum Dubey, Carpenter, Speer, Topper et Uggla, 1988 and Toxoplasma gondii Nicolle et Manceaux, 1908 than other canine populations for their different lifestyle. The aim of our survey was to determine the seroprevalence of N. caninum and T. gondii in hunting dogs from southern Italy and assess risk factors related to these protozoan infections. Blood samples were collected from 398 hunting dogs (19 different breeds, aged from 5 month to 14 years). The sera were screened by indirect fluorescence antibody test; a titre ≥ 50 was considered positive. Antibodies to N. caninum and T. gondii were detected in 59 (15%) dogs with titres from 50 to 3 200 and in 94 (24%) dogs with titres from 50 to 1 600, respectively, with co-infection in 25 (6%) dogs. Statistical difference (p ≤ 0.05) was found only for infection with T. gondii between two age groups: ≥ 2-4 years (16%) and ≥ 4-7 years (33%); other observed characteristics were without statistical significance. Our results suggest that the hunting dogs could play an important role in the transmission cycle of N. caninum between wild animals and livestock. This is the first detection of antibodies to T. gondii in hunting dogs in Italy., Tereza Machačová, Eva Bártová, Kamil Sedlák, Radka Slezáková, Marie Budíková, Diego Piantedosi, Vincenzo Veneziano., and Obsahuje bibliografii
The consumption of horse meat has been epidemiologically linked to clinical toxoplasmosis in humans and neosporosis that may cause clinical illness in horses. Here we determined seroprevalence of antibodies against Toxoplasma gondii Nicolle et Manceaux, 1908 and species of Neospora Dubey, Carpenter, Speer, Topper et Uggla, 1988 in horses from Italy. Blood samples were collected from 643 apparently healthy horses from 60 farms of 51 municipalities in southern Italy. The presence of antibodies against T. gondii and Neospora spp. were detected by indirect fluorescence antibody test (IFAT); a titre ≥ 50 was considered positive. The same sera were also tested for antibodies against Neospora spp. by a competitive-inhibition enzyme-linked immunosorbent assay (cELISA); samples with ≥ 30% inhibition were considered positive. Antibodies against T. gondii and Neospora spp. were detected in 19 (3.0%) and 15 (2.3%) horses by IFAT, respectively, without statistical difference between gender, age and breeds (p-value ≥ 0.05). Antibodies against species of Neospora were detected in 70 (10.9%) horses by cELISA with statistical difference in gender (6.0-18.5%, p-value ≥ 0.05) and breeds (0-19.4%, p-value ≥ 0.05). Although T. gondii infection rates were low, the risk of human infection should not be dismissed, particularly in Italy where consumption of raw or undercooked horse meat has a long tradition., Eva Bártová, Tereza Machačová, Kamil Sedlák, Marie Budíková, Ugo Mariani, Vincenzo Veneziano., and Obsahuje bibliografii