Search results for "Toxoplasma gondii"

Kindness to the final host and vice versa: A trend for parasites providing easy prey?

2019

Traditionally the “extended phenotype” concept refers to parasites that manipulate host phenotype to increase parasite fitness. This includes parasites that render intermediate hosts more susceptible to predation by final hosts. We explore here the proposition that an evolutionary driver in such cases is the energetic benefit to the final host, in addition to increased parasite fitness. We will review some well-established host-manipulation models, where such a scenario seems likely. One example is provided by the protozoan Toxoplasma gondii, which conspicuously impairs predator avoidance in rodents. Pathologies in humans that acquire T. gondii are known, but infection in adult feline defin…

Retrospective Serological Evidence of High Exposure of Globally Relevant Zoonotic Parasite Toxoplasma Gondii in The Latvian Population

2019

Abstract Toxoplasmosis is an important infection caused by the single-celled parasite Toxoplasma gondii, which is a zoonotic parasite causing widespread human and animal diseases, mostly involving the central nervous system. Humans can acquire toxoplasmosis by ingestion of raw or undercooked meat containing T. gondii tissue cysts, ingestion of oocysts shed by infected felids via contaminated food or water, and by vertical transmission to the fetus through the placenta from the mother during pregnancy. The aim of the present study was to determine the seroprevalence of specific anti-T. gondii IgG and IgM antibodies using a large set of clinical diagnostic laboratory data obtained over a 14-y…

Evaluation of five automated and one manual method for Toxoplasma and human DNA extraction from artificially spiked amniotic fluid.

2018

International audience; Objectives - Molecular detection of Toxoplasma gondii plays a crucial role in the prenatal and neonatal diagnosis of congenital toxoplasmosis (CT). Sensitivity of this diagnosis is partly related to the efficiency of parasite DNA extraction and amplification. DNA extraction methods with automated platforms have been developed. Therefore, it is essential to evaluate them in combination with adequate PCR amplification assays.Methods - In this multisite study, we investigated the suitability of two recent automated procedures for the isolation of Toxoplasma DNA from amniotic fluid (AF) (Magtration system 12GC, PSS and Freedom EVO VacS, Tecan), compared with three other …

Toxoplasma gondii detection and viability assays in ham legs and shoulders from experimentally infected pigs

2015

Abstract Epidemiological studies of toxoplasmosis show that infection in humans is mainly caused by the consumption of raw, undercooked or cured meat. Cured “Serrano” ham is a typical pork product from the Mediterranean area, highly valued for its flavour. The “Serrano” ham is prepared from pork meat and undergoes a process known as curing and a subsequent fermentation without thermal or smoking treatments. The viability of Toxoplasma gondii in hams and shoulders from experimentally infected pigs that have been subject to different curing processes has been studied in order to evaluate the best method to completely eliminate the viable protozoa. The different treatments include, i) freezing…

Seroprevalence of Toxoplasma gondii in domestic pigs, sheep, cattle, wild boars, and moose in the Nordic-Baltic region: A systematic review and meta-…

2019

Background: Toxoplasma gondii is an important foodborne zoonotic parasite. Meat of infected animals is presumed to constitute a major source of human infection and may be a driver of geographical variation in the prevalence of anti-T. gondii antibodies in humans, which is substantial in the Nordic-Baltic region in northern Europe. However, data on seroprevalence of T. gondii in different animal species used for human consumption are scattered. Methods: We conducted a systematic review of seroprevalence studies and meta-analysis to estimate the seroprevalence of T. gondii in five animal species that are raised or hunted for human consumption in the Nordic-Baltic region: domestic pigs (Sus sc…

Early detection of Toxoplasma infection by molecular monitoring of Toxoplasma gondii in peripheral blood samples after allogeneic stem cell transplan…

2004

International audience; Background. Isolated case reports have shown that recipients of allogeneic hematopoietic stem cell transplants ( HSCTs) who develop toxoplasmosis may have circulating Toxoplasma gondii DNA in peripheral blood before the onset of clinical symptoms. Methods. We prospectively studied 106 T. gondii - seropositive adult recipients of HSCTs for the incidence of reactivation of toxoplasmosis in the first 6 months after transplantation. Toxoplasmosis infection ( TI) was defined by a positive result of polymerase chain reaction ( PCR) of peripheral blood specimens, whereas toxoplasmosis disease ( TD) was defined as an invasive infection. Results. The incidence of TI was 16% (…

Selective permeabilization of infected host cells with pore-forming proteins provides a novel tool to study protein synthesis and viability of the in…

2001

Seroprevalence of Toxoplasma gondii antibodies in wild dolphins from the Spanish Mediterranean coast.

2004

Although Toxoplasma gondii infection has been found occasionally in cetaceans, little is known of the prevalence of antibodies to T. gondii in wild dolphins. Antibodies to T. gondii were determined in serum samples from 58 dolphins stranded in the Spanish Mediterranean coast. Modified agglutination test was used to determine T. gondii antibodies, and a titer of 1:25 was considered indicative of T. gondii infection. Antibodies to T. gondii were found in 4 of 36 striped dolphins (Stenella coeruleoalba), in 2 of 4 common dolphins (Delphinus delphis), in 4 of 7 bottlenose dolphins (Tursiops truncatus), and in 1 harbour porpoise (Phocoena phocoena). Antibodies were not found in 9 Risso's dolphin…

Toxoplasma gondii down-regulates MHC class II gene expression and antigen presentation by murine macrophages via interference with nuclear translocat…

2001

The obligate intracellular protozoan parasite Toxoplasma gondii is able to establish persistent infections within human and animal hosts. We have shown recently that T. gondii down-regulates IFN-γ-induced MHC class II expression in murine bone marrow-derived macrophages (BMMΦ). As shown in this study, the capacity of IFN-γ-activated murine BMMΦ to present ovalbumin to CD4+ T cell hybridomas was dose-dependently inhibited by T. gondii. IFN-γ-induced up-regulation of H2-Aa, H2-Ab, H2-Eb, H2-Ma, H2-Mb, H2-Oa and invariant chain transcripts was prominently down-regulated by T. gondii. Furthermore, mRNA levels of class II transactivator and interferon-regulatory factor-1 were significantly dimin…

Toxoplasma gondii seroprevalence varies by cat breed.

2017

Toxoplasma gondii is a widespread zoonotic parasite that is relevant for veterinary and public health. The domestic cat, the definitive host species with the largest worldwide population, has become evolutionarily and epidemiologically the most important host of T. gondii. The outcome of T. gondii infection is influenced by congenital and acquired host characteristics. We detected differences in T. gondii seroprevalence by cat breed in our previous studies. The aims of this study were to estimate T. gondii seroprevalence in selected domestic cat breeds, and to evaluate whether being of a certain breed is associated with T. gondii seropositivity, when the age and lifestyle of the cat are tak…