virulence

Scientists decipher genome of fungus that can cause life-threatening infections

... 13 in Science Express, revealeddifferences in the virulence strategies used by C. neoformans comparedto other ...ort as 7 to 10 days following diagnosis."The major virulence factor of C. neoformans is its extensivepolysaccharide capsule, an elaborate and dynamic structure s...

Scientists reveal molecular secrets of the malaria parasite

...ences between themalarial species are found in the virulence factors (which are at thechromosome ends) while the "housekeeping" genes are almost totallyunchanged. * Researchers showed that the parasite genes evolve mostrapidly when they are expressed in the mammal hosts (human/mouse). Thatmay represent a mecha...

Multiple Campylobacter Genomes Sequenced

...eces of DNA may carry genes that improve bacterial virulence or fitness, so their presence could help to explai...l., who also describe a new putative Campylobacter virulence locus. Further work is needed to relate these genomic differences to functional differences, but thi...

Light therapy may combat fungal infections, new evidence suggests

...sponse. Loss of the same genes also reduces fungal virulence in mice, they reported. Earlier studies had linke...ungus died by day 30. The finding points to novel virulence pathways, Heitman said, as the BWC1 and BWC2 mutants were not impaired for any of the characteristic...

Immune system's distress signal tells bacteria when to strike back

...l they are sufficiently numerous, they produce two virulence factors, molecular weapons known as PA-I and Pyocyanin. PA-I causes the barrier cells that line the host's bowel to become more permeable, which renders them more susceptible to the microbe's toxins. Pyocyanin enhances the germ's ability to pass thro...

Novel plague virulence factor identified

...ter have identified a previously unknown family of virulence factors that make the bacterium responsible for th...common roundworm is a valid model for studying the virulence of Yersinia pestis, the bacterium that causes plague. They also showed that the interaction between ...

New Look at DNA Hints at Origin of UV Damage

...ter have identified a previously unknown family of virulence factors that make the bacterium responsible for th...common roundworm is a valid model for studying the virulence of Yersinia pestis, the bacterium that causes plague. They also showed that the interaction between ...

Emerging staph strains found to be increasingly deadly and deceptive

...become severe or fatal is not well understood, but virulence is often associated with certain strains," says Jovanka Voyich, Ph.D., of RML, the study's lead author. To cause human disease, bacterial pathogens must avoid being killed by neutrophils. "These results," says Dr. Voyich, "suggest that community-acqu...

CO2 sensing proves critical for fungal pathogens to adapt to life in air and human hosts

...nsport are involved in many cellular processes and virulence attributes of diverse pathogenic bacteria and fung...olution, have different attributes governing their virulence in humans. For C. albicans, a transition between different morphological forms ("yeast" and "filamen...

Small molecule inhibitor of cholera discovered

...entified several that turned off the expression of virulence proteins, factors that help the bacteria invade it...Since most disease-causing organisms use elaborate virulence factors such as toxins to do their damage, the new approach should be widely applicable. "There is n...

Scientists determine structure of enzyme that disrupts bacterial virulence

..."turn on" a variety of genes, often increasing the virulence of the accumulating bacteria. This population-sensing results in a type of bacterial "group think" because certain genes are not turned on until a minimum number of bacteria are present. Hence, this phenomenon is called quorum-sensing. "Being ab...

New possibilities for flu antiviral and vaccine research emerge from 'Spanish flu' virus

...so provide a benchmark for measuring the potential virulence of future flu strains as they emerge. Using the v...extreme virulence. One gene associated with high virulence was the HA gene, which encodes the hemagglutinin surface protein that helps the virus attach to cell...

Breaking the mold: Research teams sequence three fungus genomes

...olite production. In other words, A. fumigatus 's virulence genes are likely complex and mixed up with normal metabolic capabilities, Nierman says. He and his colleagues now plan to systematically "knock out," or disable, genes that might make A. fumigatus infectious. Eventually, Nierman adds, this work cou...

The bioweapon is in the post

...k is that terrorists could order genes thatfconfer virulence to dangerous pathogens such as the Ebola virus, and engineer them into another virus or bacterium. They could also order genes for a hazardous bacterial toxin ?although many of these are also available by isolating the microorganisms from the environ...

Bacteria that cause tooth decay able to survive without important biochemical pathway

...has been demonstrated to be important to bacterial virulence and growth and has the potential to become a target in fighting infectious diseases, he said. "Really, we started with a very basic question related primarily to S. mutans, 'how does this bacteria tolerate acid?'" said Brady. "Asking that question h...

UCSD study finds anthrax toxins also harmful to fruit flies

... flies can be used to test the effects of a single virulence factor, such as the LF or EF toxins, on signaling pathways shared by flies and humans. Guichard and her co-authors applied lethal factor toxin to fruit fly embryos and larvae and observed that a component of the expected signaling pathway was inacti...

Wisconsin scientists discover a master key to microbes' pathogenic lifestyles

... cell shape, cell wall composition, and changes in virulence gene expressions." These changes, according to Kl...iscovery of the switch that governs dimorphism and virulence in this prevalent class of fungi provides a target for new therapeutic agents and might even help un...

Driver of anthrax toxicity could lead to late-stage therapy

... biological interest and bioterrorism concern. The virulence of the bacteria depends on separate complexes formed by interaction of a carrier protein, protective antigen, with lethal and edema factors responsible for the toxic effects and swelling that impairs the host's immune response. In the current study...

Scientists discover a new disease-causing bacterium in an immune-compromised patient

...able genomes of CGD pathogens may provide clues to virulence properties that they share in common," according to the article. ...

Soil-bound prions that cause CWD remain infectious

...able genomes of CGD pathogens may provide clues to virulence properties that they share in common," according to the article. ...

UGA study explains peaks and troughs of dengue epidemics

...temporary cross-immunity and variation in serotype virulence play in epidemics. They found that cross-immunity alone is enough to create the patterns that are observed in nature. The study is a major departure from other theories about what drives dengue epidemics. The conventional wisdom is that an amplific...

Silence of the amoebae

...cessfully silence the expression of two additional virulence genes in the same amoebae. Rivka Bracha and coll... scientists report the silencing of two additional virulence genes in the same amoebae using a similar plasmid-induced principle. The disabled amoebae, thoug...

Malaria, potato famine pathogen share surprising trait

...t they were. But although the mechanism of getting virulence proteins into a host cell is very similar, the infection-causing proteins that are delivered to a host are completely different." To Kamoun's knowledge, this is the first paper to show that such dissimilar pathogens of this type - both are eukaryoti...

Bacteria give up secrets in war waged on plants

...tegy for bacteria, very clever." The P. syringae virulence protein, called HopM1, has been the mechanism mystery. Plant diseases, ranging from bacterial speck in tomatoes and fire blight in apples and pears can devastate crops. Human bacterial pathogens use a similar basic principle to cause diseases. "Bac...

HIV-1's high virulence might be an accident of evolution

The virulence characteristic of HIV-1--the virus predominantly responsible for human AIDS--might amount to an accident of evolution, new evidence reveals. A gene function lost during the course of viral evolution predisposed HIV-1 to spur the fatal immune system f...

Potato blight pathogenicity explained by genome plasticity

...ort, set out to identify the genetic basis for the virulence of specific Dutch P. infestans strains. The outcome of their efforts was the identification of single gene, called pi3.4 , that was present as a single, full-length copy in both the virulent and avirulent strains. They also identified multiple c...

Mouse study reveals new clues about virulence of 1918 influenza virus

... synergistically that accounts for the exceptional virulence of this virus. Michael G. Katze, Ph.D., of the University of Washington School of Medicine, Seattle, a grantee of the National Institute of Allergy and Infectious Diseases (NIAID), one of the National Institutes of Health (NIH), led the research te...

MRSA vaccine shows promise in mouse study

...the specific cell-surface proteins responsible for virulence and can recognize them from multiple strains." The researchers turned to a newer technique, known as "reverse vaccinology," recently used to develop candidate vaccines against group A and group B streptococci and group B meningococci. Access to th...

A wolf in sheep's clothing: Plague bacteria reveal one of their virulence tricks

...ia insert into their host cells proteins and other virulence factors, which kill by -- among other things -- di...ytoskeleton," Stebbins says, "but it decreases its virulence significantly." "It's rare to find something that has such a strong effect that you can hit one pro...

Caterpillars tell us how bacteria cause disease

...th of evolutionary time. It seems likely that most virulence genes around today probably first evolved to work ...given us a cheap and easy way of mapping bacterial virulence factors across an entire genome. This will allow us to rapidly and inexpensively bridge the enormous...

Stanford discovery may help predict when toxoplasma can be deadly

...a strain that contains the proteins that increase virulence is the cause of the infection. Humans can becom...The group's further exploration of the Toxoplasma virulence process may also have implications for immune-system modulating drugs that could specifically damp...

Resistance and genetic sensitivity to sleeping sickness

...ty to respond to infection, the degree of parasite virulence or pathogenicity and the environment. An IRD team focused particularly on the role of host genetic diversity in response to T. b. gambiense infection (whether or not the disease develops). As human experimentation is excluded, genetic, epidemiolog...

Study illuminates how the plague bacteria causes disease

...s for fighting the bug. "Yersinia injects several virulence factors into its host," said C. Erec Stebbins of R...o see such a critical and unexpected factor in the virulence of Yersinia--a bacteria historically responsible for some of the worst diseases," he added. Although...

Tearing down the fungal cell wall

...s to play an important role in the development and virulence of Alternaria brassicicola. A. brassicicola, a destructive fungal pathogen that causes black spot disease on most cultivated Brassica crops worldwide, results in considerable leaf loss in many economically important crops including canola, cabbage a...

MRSA toxin acquitted: Study clears suspected key to severe bacterial illness

...roups previously have proposed that PVL is the key virulence factor. But new evidence strongly suggests that...e Bernard in Lyon, France, decided to test the PVL virulence theory, thinking that if they could understand the role of this toxin in disease, they could more qu...

Scientists identify specific enzymes that make meningitis hard to fight

...ave long understood that the secret of meningitis' virulence lies in its ability to rearrange its DNA and thus change its external appearance to the body's immune system. Significantly our research has now demonstrated that the ability of meningitis to repair its DNA is important for its ability to survive att...

Pacific Rim researchers to collaborate on distributed bioinformatics analysis of avian flu

...actions among major factors that may determine the virulence of a virus; and Test whether the multinational collaboration can establish a successful, large-scale, distributed computational data grid. Scientists at UC San Diego, the California Institute for Telecommunications and Information Technolog...

Study uncovers a lethal secret of 1918 influenza virus

...unctions and interactions. Learning more about the virulence mechanisms of the 1918 flu virus may help researchers understand how to keep the virus from causing such a severe immune response. "This study in macaques, combined with our earlier research showing the host response in mice infected with the 1918 ...

Changes in amino acids in the 1918 influenza virus cut transmission

...had an alpha-2,3 binding activity, replication and virulence didn't change," explains Dr. García-Sastre. "These animals still had symptoms, however transmission was practically abolished." Since the artificially-generated virus featured alpha-2,3 sialic acid binding activity, this finding indicated that alpha-...

Corals that can fight global warming may one day help fragile reefs

...erior. Moreover, the warmer waters cause increased virulence of some pathogens as well as a diminished ability of corals to fight them. But these complications can also be keys to coral reef survival. "A first line of defense is provided by surface microorganisms ?[that] produce antibiotics that can help cor...

Scientists discover rare 'gene-for-gene' interaction that helps bacteria kill their host

...obacco hornworm) to study the bacteria's so-called virulence genes. "The beauty of this research is that we have been able to study the whole genome of the bacteria to work out how it kills its host," said Professor Stuart Reynolds from the University of Bath. "People studying diseases think that the ki...

Potent possibilities for parasite attack

...ve very similar sequences. "CFAS is involved in virulence and persistence in Mycobacterium, causative agent ...ishmania raises the exciting possibility that some virulence factors are conserved between bacterial and eukaryotic intracellular pathogens," said Jeremy Mottram...