Virulence and parasite. Medical search. Frequent questions

Researchers have discovered how the parasite Toxoplasma gondii is able to cross the blood-brain barrier. (neurosciencenews.com)
Is the brain parasite Toxoplasma manipulating your behavior, or is your immune system to blame? (neurosciencenews.com)
Toxoplasma gondii is a single-celled parasite of all warm-blooded hosts worldwide. (usda.gov)
The protozoan parasite Toxoplasma gondii is one of the known most successful eukaryotic pathogens on Earth. (usda.gov)
Do the placental barrier, parasite genotype and Toll-like receptor polymorphisms contribute to the course of primary infection with various Toxoplasma gondii genotypes in pregnant women? (springer.com)
We therefore introduce the reader to CRISPR-based screens in the related apicomplexan Toxoplasma gondii and discuss how these approaches could be adapted to develop CRISPR/Cas9 based genome-scale genetic screens in malaria parasites. (portlandpress.com)
2019. Comparative virulence of Caribbean, Brazilian and European isolates of Toxoplasma gondii . (hutton.ac.uk)
Background: Toxoplasma gondii is a zoonotic parasite of global importance. (gla.ac.uk)
Toxoplasma gondii is a parasite that is found in approximately 30 % of the human population. (bvsalud.org)
El Toxoplasma gondii es un parásito que se encuentra, aproximadamente, en el 30 % de la población humana. (bvsalud.org)
Toxoplasmosis is caused by infection with the protozoan Toxoplasma gondii, an obligate intracellular parasite. (medscape.com)
The parasite was named Toxoplasma (arclike form) gondii (after the rodent) in 1909. (medscape.com)

Antigens encoded by the var gene family are major virulence factors of the human malaria parasite Plasmodium falciparum, exhibiting enormous intra- and interstrain diversity. (org.in)
A Unique Virulence Gene Occupies a Principal Position in Immune Evasion by the Malaria Parasite Plasmodium falciparum. (cornell.edu)
Mutually exclusive gene expression, whereby only one member of a multi-gene family is selected for activation, is used by the malaria parasite Plasmodium falciparum to escape the human immune system and perpetuate long-term, chronic infections. (cornell.edu)
In the last few years, chromatin modifications have been extensively studied in the malaria parasite Plasmodium falciparum (for recent reviews, see [9] - [13] ). (plos.org)
This project focuses on the malaria parasite Plasmodium. (europa.eu)
It aims to transform our understanding of the basic biology of Plasmodium, and of how that biology affects virulence. (europa.eu)
The ∼30 Mb genomes of the Plasmodium parasites that cause malaria each encode ∼5000 genes, but the functions of the majority remain unknown. (portlandpress.com)
Antibiotics and antiparasitic agents are increasingly failing due to the evolution of resistance to them by their target pathogens, notably protozoan parasites and bacteria like Plasmodium, Leishmania, Pseudomonas aeruginosa and Staphylococcus aureus. (ibecbarcelona.eu)
During year 1, the fellow will be trained by the team in the techniques that will be used during the study, especially the in vitro culture of pathogenic bacteria (P. aeruginosa, S. aureus and others), Plasmodium falciparum, and Leishmania infantum parasites, and the techniques for drug encapsulation and their targeted delivery. (ibecbarcelona.eu)
Haemoproteus and Plasmodium species are widespread avian blood parasites. (cabi.org)
Several Plasmodium species are known for their high virulence and have caused significant declines in naïve bird populations. (cabi.org)

Pathogens may be intentionally or unintentionally genetically modified to change virulence and other characteristics. (wikipedia.org)
Increased prevalence and virulence of parasites and pathogens may reduce survival. (ices.dk)
This can be achieved by encapsulating them in nanocarriers targeted to the parasite or bacterial cells, which will increase the local amounts being delivered to the pathogens, boosting in this way the efficacy of the medicines. (ibecbarcelona.eu)
will preferentially be DNA aptamers developed ad hoc against either whole parasite cells or specific known protein markers of the pathogens. (ibecbarcelona.eu)
During year 2, the fellow will develop DNA aptamers against the selected parasite cells and/or recombinant proteins from the pathogens and will explore their capacity to block their growth in in vitro cultures. (ibecbarcelona.eu)
Sepsis can originate from infections caused by a wide array of pathogens: bacteria, virus, parasites or fungi. (lu.se)
Distinct pathogens use a diverse arsenal of molecular weapons to establish infection, designated virulence factors. (lu.se)
Pathogens, such as bacteria, viruses and parasites, that cause disease in humans and animals may depend partially or entirely for their existence on other physical, chemical, or biological factors. (who.int)

Protozoan parasites of the genus Leishmania undergo a complex life cycle involving transmission by biting sand flies and replication within mammalian macrophage phagolysosomes. (pasteur.fr)
To study truly lpg(-) parasites, we generated Leishmania major lacking the gene LPG1 [encoding a putative galactofuranosyl (Gal(f)) transferase] by targeted gene disruption. (pasteur.fr)
Nicolas Cermakian, a professor at McGill's Department of Psychiatry and researcher at the Douglas Institute, made the discovery using Leishmania, a parasite that causes leishmaniasis and that is transmitted at night by the female sandfly. (eurekalert.org)
Although the parasite is mostly located in tropical areas, climate change could spread Leishmania far beyond where it is found today. (eurekalert.org)
The circadian clock in immune cells controls the magnitude of Leishmania parasite infection, Silke Kiessling et al. (eurekalert.org)
Cutaneous leishmaniasis is caused by infection with the protozoan parasite Leishmania, which resides intracellularly in dermal macrophages (Mø), producing lesions. (bvsalud.org)
To distinguish the influence of the parasite from the inflammatory microenvironment after Leishmania major (LM) infection on the Mø, we performed single-cell RNA sequencing and compared Mø associated with LM transcripts (or 'infected' Mø) with Mø not associated with LM transcripts (or 'bystander' Mø) within the lesions. (bvsalud.org)
The important intracellular parasite Leishmania sp is also presented, which, in contrast, has its virulence improved by viral infections. (bvsalud.org)

The evolution of parasite virulence and the origin of cooperative genomes in primitive cells are both problems that balance cooperative and competitive interactions among symbionts. (stevefrank.org)
First, Adaptation and the evolution of parasite virulence in a connected world: Adaptation is conventionally regarded as occurring at the level of the individual organism, where it functions to maximize the individual's inclusive fitness. (scienceblogs.com)
However, it has recently been argued that empirical studies on the evolution of parasite virulence in spatial populations show otherwise. (scienceblogs.com)

Using viral load and CD4+ T cell measures from 2014 HIV-1 subtype B infected individuals enrolled in the Swiss HIV Cohort Study, we investigated if virulence - measured as the rate of decline of CD4+ T cells - and per-parasite pathogenicity are heritable from donor to recipient. (biorxiv.org)
Interestingly, the pattern of evolution of all these traits differs significantly from neutrality, and is most consistent with stabilizing selection for the set-point viral load, and with directional selection for the CD4+ T cell decline and the per-parasite pathogenicity. (biorxiv.org)
cag, a pathogenicity island of Helicobacter pylori, encodes type I-specific and disease-associated virulence factors. (semanticscholar.org)
In order to establish the course of infection, virulence and pathogenicity, a Paraguayan Trypanosoma cruzi strain isolated from a 12 year old patient in 1989, Balb/c mice were inoculated, and the number of parasites were determined by direct parasitemia (micromethod). (bvsalud.org)

Bacteria and parasites continue to be recognized as important causes of diarrhea worldwide. (cdc.gov)
Use of EIAs, tissue culture, molecular probes, and the polymerase chain reaction has improved the diagnosis of diarrhea caused by bacteria, and special concentrating and staining techniques have improved the process of detecting parasites such as Cryptosporidium and I. belli. (cdc.gov)
A myriad of agents can potentially be transmitted through blood transfusions, including bacteria, viruses, and parasites. (medscape.com)

A family of genes called var encodes the chief antigenic and virulence determinant of P. falciparum malaria. (cornell.edu)
In particular, switching seems not to be random, but instead appears to be coordinated to result in timely activation of individual genes leading to sequential waves of antigenically distinct parasite populations. (cornell.edu)
The genome of P. falciparum contains hundreds of genes that show CVGE, such that individual parasites within an isogenic population express these genes at very different levels, often fully active or completely silenced [15] . (plos.org)
In the present study the authors found that certain genes (ROP 5 and ROP 18) affect the virulence of the parasite. (usda.gov)
Simultaneous identification of bacterial virulence genes by negative selection. (semanticscholar.org)

In the present study, we have performed PCR-RFLP genotyping analysis on a diverse array of globally distributed T.gondii strains at four ROP gene loci including ROP18, ROP5, ROP16 and ROP17 that previously implicated in influencing T. gondii virulence and pathogenesis. (usda.gov)

Pathogen strains may differ in virulence because they attain different loads in their hosts, or because they induce different disease-causing mechanisms independent of their load. (biorxiv.org)
They're less able to tolerate their pathogen, so the parasite becomes more hurtful…to them. (scientificamerican.com)
Enhanced understanding of pathogen derived virulence attributes can facilitate development of novel anti-infectives aimed at distinct virulence factors. (lu.se)
This approach has been called " genomic epidemiology "-using pathogen genome sequences to detect emerging diseases, assess their potential virulence and resistance to antibiotics, and monitor their spread in populations. (cdc.gov)

We demonstrate through correlation with published virulence data that the combination of ROP18 and ROP5 allele types is highly predictive of T. gondii virulence across a broad range of global T. gondii isolates. (usda.gov)
These findings indicate that the importance of ROP18 and ROP5 in determining strain virulence is not limited to the North American/European archetypal lineages most commonly used in molecular studies, but also appears to apply to diverse isolates from South/Central America and Asia. (usda.gov)
DNA was extracted from tachyzoites of each of the 8 T. gondii isolates and genotyped at four ROP gene loci, including ROP5, ROP16, ROP17 and ROP18 to look for association with markers of virulence. (gla.ac.uk)
Caribbean isolates of intermediate virulence (ToxoDB #141 and #265) all had the same ROP18/ROP5 allelic profile (2/2). (gla.ac.uk)
The ROP protein allelic profile of the virulent Caribbean and Brazilian isolates differed indicating that perhaps other factors are involved in predicting virulence. (gla.ac.uk)
isolates as a panel of parasites. (fu-berlin.de)

Although bats serve as reservoir hosts with great viral diversity, little evidence exists for corresponding death or illness of bats from viruses (other than lyssaviruses) that have spread into humans and domesticated mammals with high virulence. (cdc.gov)
We hypothesize that the increased metabolism and higher body temperatures of bats during flight might serve as an evolutionary adjuvant to their immune systems, providing a powerful selective force against virulence and promoting the diversity of viruses that infect bat populations. (cdc.gov)
Perhaps counter- intuitively, this would enable bats to tolerate a greater diversity of viruses that have a high potential for virulence when transmitted to other mammals. (cdc.gov)
Used with microorganisms, viruses, and parasites for studies of their ability to cause disease in man, animals, or plants. (bvsalud.org)

Cats are the main reservoir of T. gondii because they are the only hosts that can excrete the resistant stage (oocyst) of the parasite in the feces. (usda.gov)
Virulence of T. gondii strains varies greatly in mice, and mounting evidence suggests that such variations may be relevant to the manifestation of human toxoplasmosis. (usda.gov)
However, the distribution of virulence gene alleles in natural populations and the broad influence of these allele combinations on T. gondii virulence have not been examined in depth. (usda.gov)
RFLP analysis of these loci may thus serve as a valuable tool in determining the potential virulence of uncharacterized T. gondii strains in future studies. (usda.gov)
Genotype I of T. gondii is most virulent for mice, inducing extensive parasite dissemination and sudden murine death. (springer.com)
The aim of this study was to compare the virulence of T. gondii strains isolated in the Caribbean to a virulent Brazilian strain and an avirulent European strain. (gla.ac.uk)
A narrative bibliographic review article was done with the search of original and review articles in international scientific mentales en adultos journals, in English and Spanish listing the relationship between the seroprevalence of T. gondii and the development of mental disorders in the adult population. (bvsalud.org)
Nicolle and Manceaux first described the organism in 1908, after they observed the parasites in the blood, spleen, and liver of a North African rodent, Ctenodactylus gondii . (medscape.com)

Although virulence is typically attributed to single pathogenic strains, here we investigated whether effectors secreted by a population of non-virulent strains could function as public goods to enable the emergence of collective virulence. (nature.com)
We conclude that studies on TLR contributions in the maternal-fetal transmission of particular parasite strains and congenital toxoplasmosis are warranted. (springer.com)

Cortés A, Crowley VM, Vaquero A, Voss TS (2012) A View on the Role of Epigenetics in the Biology of Malaria Parasites. (plos.org)
Malaria parasites replicate inside the cells of their human host via 'schizogony', which is fundamentally different from conventional binary fission - the replication mode used by most cells from human cells to yeast cells. (europa.eu)
Though our message is general - we can expect the life-histories of all parasites to have evolved phenotypic plasticity - we focus our discussion on malaria parasites. (ed.ac.uk)
Here, we review the arrival of genetic screens in malaria parasites to analyse parasite gene function at a genome-scale and their impact on understanding parasite biology. (portlandpress.com)
CRISPR/Cas9 screens, which have revolutionised human and model organism research, have not yet been implemented in malaria parasites due to the need for more complex CRISPR/Cas9 gene targeting vector libraries. (portlandpress.com)

The malaria parasite is an unusual, early-diverging protozoan lifeform. (europa.eu)
Dermo disease results when the eastern oyster Crassostrea virginica is infected by the protozoan parasite Perkinsus marinus . (vims.edu)

Gain of virulence changes that leave the open reading frame of the Avr gene itself unchanged may be more easily reversible, should appropriate conditions occur for the re-deployment of an Avr allele that has been suppressed or wiped out of the population through a selective sweep. (frontiersin.org)
Antimicrobial susceptibility, virulence gene profiles and molecular subtypes of Salmonella Newport isolated from humans and other sources. (cdc.gov)

Each coisogenic strain was individually unfit, but the metaclone was collectively as virulent as the wild-type strain on Arabidopsis thaliana , suggesting that effectors can drive the emergence of cooperation-based virulence through their public action. (nature.com)
It was more fundamentally due to the emergence of a new and highly virulent form of Perkinsus marinus , the parasite that causes Dermo. (vims.edu)
Just as anthrax is more virulent than athlete's foot, a more virulent ant parasite kills a larger proportion of the adult ants at the nest it raids. (the-scientist.com)

Polymorphic rhoptry-secreted kinases and pseudokinases (ROP) have been demonstrated to account for murine virulence among the archetypal clonal parasite lineages that dominate the populations of North America and Europe. (usda.gov)

Whilst unicellular parasites face many of the same selective pressures and trade-offs, plasticity in their phenotypic traits has been largely overlooked and remains poorly understood. (ed.ac.uk)
Members of the phylum Apicomplexa are unicellular parasites that cause many important livestock and human diseases including malaria and toxoplasmosis [ 1 , 2 ]. (portlandpress.com)

The 2019 GRC will include disease-focused sessions from Innovation to Global Health Impact for tropical bacterial infections and antibiotic resistance, emerging and re-merging TIEDs with an emphasis in new advances related to host-parasite relationships, novel technologies leading to global impact and lessons learned from the bench to the clinic. (grc.org)

When mice were injected with the parasite, Professor Cermakian's team discovered that their immune response varied greatly depending on what time of day the infection occurred. (eurekalert.org)
Five mice per group were euthanized at day 8 post-inoculation (p.i.) and parasite burden was determined in heart, lungs and eyes using quantitative PCR. (gla.ac.uk)
The remaining 10 mice per group were part of a survival experiment to assess virulence. (gla.ac.uk)
Significantly higher parasite burdens were recorded in the lungs and eyes of mice infected with ToxoDB genotypes #13 and #6. (gla.ac.uk)

Sternberg JM, Maclean L. A spectrum of disease in human African trypanosomiasis: the host and parasite genetics of virulence. (unboundmedicine.com)
TY - JOUR T1 - A spectrum of disease in human African trypanosomiasis: the host and parasite genetics of virulence. (unboundmedicine.com)

Yet research into the factors, whether parasite or host, which control virulence in Human African trypanosomiasis is in its infancy. (unboundmedicine.com)
Thus, genetic approaches allow dissection of the roles of this complex family of interrelated parasite virulence factors, and definitively establish the role of LPG itself as a parasite virulence factor. (pasteur.fr)
Thus all the factors for parasite transmission may be concen- longipalpis from other biting flies in urban ZVL foci suggests trated within a relatively small area. (cdc.gov)
The outcome of infection in humans can depend on a number of factors including the infecting stage of the parasite, inoculating dose and virulence of the infecting strain. (gla.ac.uk)
Mannheimia hemolytica has many virulence factors that include a leukotoxin responsible for premature death of white blood cells and platelets (Gioia et al. (thebeefsite.com)
Bacterial cell wall components and toxins, for example, are well-known virulence factors for sepsis that directly contribute to the profound dysregulation of the immune response. (lu.se)

While in both cases the mechanisms remain to be elucidated, the overall infection virulence phenotype is determined by both parasite and host genotype. (unboundmedicine.com)

Here, we demonstrate that evolutionary theory, developed to explain variation observed in the life-history traits of multicellular organisms, can be applied to parasites. (ed.ac.uk)
We use an evolutionary framework to explain the trade-offs that parasites face and how plasticity in their life history traits will be expressed according to changes in their in-host environment. (ed.ac.uk)
Several evolutionary processes influence virulence, the amount of damage a parasite causes to its host. (semanticscholar.org)
In an unusual twist, the team's evidence suggests that transformation of this native parasite was in response to evolutionary pressures brought by the impacts of another, non-native oyster parasite known as MSX , first seen in Bay waters in 1959. (vims.edu)

Low virulence coupled with high diversity has led to the suggestion that bats have evolved mechanisms to control viral replication more effectively than have most mammals and that some attribute common to all bats might also explain the apparent low virulence of viral infections in these animals. (cdc.gov)

Study suggests new avenues for treating toxoplasmosis parasite infections. (neurosciencenews.com)
Testing whether variation in parasites traits is adaptive will provide new and fundamental insights into the basic biology of parasites, their epidemiology and the processes of disease during individual infections. (ed.ac.uk)
Severe infections lead to oyster death and release of parasites into the surrounding water, potentially infecting other nearby oysters as they filter water for food. (vims.edu)

Many processes in parasite biology involve changes at the chromatin level, including regulation of transcription along a complex life cycle, delimitation of functional elements in the genome, and antigenic variation. (plos.org)

I analyze the tradeoff among three correlated traits: competitiveness against other genotypes for resources within hosts (protocells), damage to the host (virulence), and rate of horizontal transmission from one host to another. (stevefrank.org)

Timecourses have been conducted to quantify the number and type of replicating nuclei, together with other cell-biological features, in P. falciparum parasites across the course of both erythrocytic schizogony and gametogenesis. (europa.eu)

For their targeting to parasite and bacterial cells, these nanovectors can be eventually functionalized with ligands against microbial antigens. (ibecbarcelona.eu)

These are crucial issues for understanding malaria parasite virulence and drug-resistance. (europa.eu)

Understanding how parasites 'hack' the brains of their hosts may provide new insights into decision making and behavior. (neurosciencenews.com)

It fits within the same species but it doesn't seem to have the same level of virulence,' he said. (cbc.ca)
Although the most serious nematode parasites of grape will be listed below, it is important to note vineyards typically contain three of more genera/species of plant-parasitic nematodes. (msu.edu)
Borrowing language from pathology, the researchers categorize the "virulence" of different raiding species. (the-scientist.com)
Results: The compounds 2H-1-benzopyran, 3,4-dihydro-2-(2-methylphenyl)-(9CI), echioidinin, and malvidin showed good results against arginase targets from three parasite species and negative results for potential toxicities. (bvsalud.org)

Evidence will be presented for both asymptomatic forms of T. b. gambiense infection and low virulence forms of T. b. rhodesiense infection in humans. (unboundmedicine.com)
Understanding virulence is important for predicting disease outcome in humans and may also aid vaccine design as well as drug discovery. (gla.ac.uk)

Working out how time regulation of host-parasite interactions are controlled, Cermakian says, might also be useful in the fight against other diseases transmitted by insects. (eurekalert.org)
Marie C, Petri WA: Regulation of virulence of Entamoeba histolytica. (msdmanuals.com)

In this paper we review the clinical evidence for virulence variation and the epidemiological and experimental data that give clues as to the mechanisms involved. (unboundmedicine.com)

However, all structural domains of LPG are shared by other major surface or secretory products, providing a biochemical redundancy that compromises the ability of in vitro tests to establish whether LPG itself is a virulence factor. (pasteur.fr)

Regressing the CD4+ T cell declines and per-parasite pathogenicities of the transmission pairs did not yield heritability estimates significantly different from zero. (biorxiv.org)

The caterpillars use those toxins to protect themselves from a deadly parasite that produces spores. (scientificamerican.com)

The necessary gain of virulence changes will depend on how the host immune system interacts with the effector ( Stergiopoulos and de Wit, 2009 ). (frontiersin.org)
In my research, I am addressing two questions using two host-parasite model systems. (fu-berlin.de)
One such work on this complex relationship environmentally persistence parasites and virulence is by Day (2002), which predicts that virulence is likely to be stronger in parasites that are transmitted upon host death. (fu-berlin.de)
Altogether, these results suggest that both the parasite and host inflammatory microenvironment independently drive transcriptional remodeling in Mø during LM infection in vivo. (bvsalud.org)

Plastic parasites: sophisticated strategies for survival and reproduction? (ed.ac.uk)
Dive into the research topics of 'Plastic parasites: sophisticated strategies for survival and reproduction? (ed.ac.uk)

Simply put, the parasite thrives when it elicits a strong immune response, attracting inflammatory cells it uses to multiply (macrophages and neutrophils) to the infection site. (eurekalert.org)

Researchers discover nitric oxide plays an unexpected role in maintaining the integrity of the blood-brain barrier, reducing parasite invasion in the brain and neuroinflammation. (neurosciencenews.com)
Spanish researchers say they have identified and were able to remove a parasite they believe is behind the collapse of honeybee colonies in Europe, but it remains unclear whether their findings are applicable to the disappearances of colonies in North America. (cbc.ca)

Anatomy18

Organisms80

Diseases50

Chemicals and Drugs45

Analytical, Diagnostic and Therapeutic Techniques and Equipment20

Phenomena and Processes54

Disciplines and Occupations2

Information Science4

Health Care1

Toxoplasma12

Plasmodium11

Pathogens8

Leishmania8

Evolution of parasite virulence3

Pathogenicity4

Bacteria3

Genes5

Pathogenesis1

Pathogen4

Isolates6

Viruses4

Gondii8

Strains2

Malaria Parasites5

Protozoan2

Gene2

Virulent3

Populations1

Unicellular parasites2

20191

Mice4

Genetics2

Factors6

Genotype1

Evolutionary4

Viral infections1

Infections3

Biology1

Genotypes1

Falciparum1

Microbial1

Resistance1

Hosts1

Species4

Humans2

Regulation2

Mechanisms1

Establish1

Declines1

Produces1

Host4

Survival2

Attracting inflammatory1

Researchers2