PRESS-NEWS.org - Press Release Distribution
PRESS RELEASES DISTRIBUTION

Zooming in on the weapons of Salmonella

2011-03-05
(Press-News.org) Some of the most dreaded diseases in the world such as plague, typhoid and cholera are caused by bacteria that have one thing in common: they possess an infection apparatus which is a nearly unbeatable weapon. When attacking a cell of the body, they develop numerous hollow-needle-shaped structures that project from the bacterial surface. Through these needles, the bacteria inject signal substances into the host cells, which re-program the latter and thereby overcome their defense. From this time on it's easy game for the pathogens; they can invade the cells unimpeded and in large numbers.

The biochemist and biophysicist Thomas Marlovits, a group leader at the Vienna Institutes IMP (Research Institute of Molecular Pathology) and IMBA (Institute of Molecular Biotechnology) has been occupied for several years with the infection complex of salmonellae. As early as in 2006 Thomas Marlovits showed how the needle complex of Salmonella typhimurium develops (Nature 441, 637-640). Together with his doctoral student Oliver Schraidt he has now been able to demonstrate the three-dimensional structure of this complex in extremely high resolution. The team was able to show details with dimensions of just 5 to 6 angstroems, which are nearly atomic orders of magnitude. Their work will be presented in the forthcoming issue of the journal Science.

Looks do kill!

Never before has the infection tool of salmonellae been presented in such precision. This was achieved by the combined use of high-resolution cryo-electron microscopy and specially developed imaging software. "Austria's coolest microscope" makes it possible to shock-freeze biological samples at minus 196 degrees centigrade and view them in almost unchanged condition. However, when "zooming in" on their object, scientists are confronted with a treacherous problem: the high-energy electron beam falls at such high concentrations on the sample that the latter is destroyed after the very first image.

The Viennese scientists have resolved the problem by developing new image-processing algorithms and with sheer numbers of images. They analyzed about 37,000 images of isolated needle complexes. Similar images were grouped and computed jointly. By doing so they were able to generate a single sharp image from numerous blurred ones. This enormous computing power was created by a cluster of about 500 interconnected computers.

Microscopy without the human interference factor

The microscope works in semi-automated fashion at night to obtain the large number of images. This is very advantageous because human beings merely interfere with the job. They breathe, speak, move, and thus unsettle the sensitive microscope. Even a moving elevator may irritate the electron beam.

The cryo-electron microscope at IMP-IMBA is the only one of its kind in Austria. The immense technical effort associated with its operation pays off, as far as the scientists are concerned. Advancing into the subnanometer range created a further means of expanding their knowledge. They were able to "adjust" existing data (obtained from crystallography) to the needle structure and thus complement the three-dimensional image in a perfect manner. The use of this hybrid method enabled the scientists to elucidate the complete construction plan of the infection apparatus.

Thomas Marlovits regards this technology as an innovation boost: "Using the methods we developed for our work, we were able to establish "imaging" standards at a very high level. We can explore its absolute limits with the aid of the fantastic infrastructure we have here at Campus Vienna Biocenter."

This knowledge not only advances basic research. "Using our data, we may well be able to find a compound that interferes with the needle complex and disturb its function," says Marlovits. "We would then have a very effective medication - one that combats not only salmonellae but also other pathogens that employ this system, such as pathogens that cause cholera, plague or typhoid."

###

The biochemist Thomas Marlovits was born in Rechnitz, Austria. He is a joint group leader of the two institutes IMP and IMBA since 2005. Previously, he spent five years as a post-doctoral student at the University of Yale. Thomas Marlovits has been occupied with the structure and function of molecular machines. He started to investigate the infection apparatus of salmonellae at Yale and continued this work at IMP-IMBA.

Thomas Marlovits' research work is supported within the scope of "Vienna Spots of Excellence" as part of the "Center of Molecular and Cellular Nanostructure Vienna (CMCN)", headed by Thomas Marlovits. This initiative of the City of Vienna supports research projects which involve both enterprises and scientific partners.

Original paper: "Three-Dimensional Model of Salmonella's Needle Complex at Subnanometer Resolution". Oliver Schraidt & Thomas C. Marlovits, Science 331, pp. 1192-1195, March 4, 2011.

END



ELSE PRESS RELEASES FROM THIS DATE:

BNCT, a new-generation radiation treatment, is effective in advanced head and neck cancer

2011-03-05
Biologically targeted BNCT treatment is based on producing radiation inside a tumour using boron-10 and thermal neutrons. Boron-10 is introduced into cancer cells with the help of a special carrier substance (phenylalanine), after which the tumour is irradiated with lowenergy neutrons. The latter react with the boron to generate high-LET radiation, which may destroy the cancer cells. One to two BNCT treatment sessions may be sufficient to destroy a tumour, while keeping the impact of radiation on surrounding healthy tissue to a minimum. A research reactor is currently ...

Racial identity tied to happiness, study finds

Racial identity tied to happiness, study finds
2011-03-05
EAST LANSING, Mich. — Black people who identify more strongly with their racial identity are generally happier, according to a study led by psychology researchers at Michigan State University. The study, funded by the National Institute of Mental Health, appears in the current issue of Cultural Diversity and Ethnic Minority Psychology, a research journal published by the American Psychological Association. "This is the first empirical study we know of that shows a relationship between racial identity and happiness," said Stevie C.Y. Yap, doctoral candidate in psychology ...

Some overweight adolescents may be at risk for weak bones

Some overweight adolescents may be at risk for weak bones
2011-03-05
AUGUSTA, Ga. - Overweight adolescents already struggling with risk factors such as insulin resistance may need to add weak bones to their list of health concerns, researchers report. A study of 143 overweight 14-18 year olds showed those with risk factors such as the precursor for diabetes and low levels of the blood-vessel protecting HDL cholesterol have less bone mass – an indicator of bone strength – than their overweight but otherwise healthy peers, according to researchers at Georgia Health Sciences University's Georgia Prevention Institute. Other risk factors ...

New system can warn of tsunamis within minutes

2011-03-05
Seismologists have developed a new system that could be used to warn future populations of an impending tsunami only minutes after the initial earthquake. The system, known as RTerg, could help reduce the death toll by giving local residents valuable time to move to safer ground. The study by researchers at the Georgia Institute of Technology appears in the March 5 edition of Geophysical Research Letters. "We developed a system that, in real time, successfully identified the magnitude 7.8 2010 Sumatran earthquake as a rare and destructive tsunami earthquake. Using this ...

Happy hour linked to pub violence

2011-03-05
A Cardiff University study has established a link between pub violence and happy hour-style drinking promotions. The findings also show that pub staff themselves need to do more to stop heavily intoxicated customers from continuing to drink. The team studied pubs and nightclubs with a history of violence across five different cities and towns in the UK. Customers entering and leaving the premises were breathalysed. The team also recorded data about the price of beer and any drink promotions at each establishment. Their findings were then linked to police and hospital ...

Virtual reality can improve design skills in younger generation

2011-03-05
COLUMBIA, Mo. ¬— Rapidly improving technology is changing everyday life for all generations. This constantly changing environment can be a difficult adjustment for older generations. However, for the current generation known as "Generation Y", this sense of constant technology adaption isn't an adjustment; it is a way of life. A University of Missouri researcher says a widening gap is occurring between educators and students due to the difference in how older and younger generations approach evolving technologies. Newton D'Souza, an assistant professor of architectural ...

Observing Arctic ice-edge plankton blooms from space

Observing Arctic ice-edge plankton blooms from space
2011-03-05
Ongoing climate-driven changes to the Arctic sea-ice could have a significant impact on the blooming of tiny planktonic plants (phytoplankton) with important implications for the Arctic ecosystem, according to new research conducted by scientists at the UK's National Oceanography Centre (NOC). "Ice-edge phytoplankton blooms in the Arctic Ocean provide food for planktonic animals called zooplankton, which are in turn exploited by animals higher up the food chain such as fish," explained Dr Andrew Yool, one of the team of NOC researchers. During the Arctic spring and ...

Novel mechanism for control of gene expression revealed

2011-03-05
(Boston) – Dr. David Levin, Professor of Molecular & Cell Biology at Boston University Henry M. Goldman School of Dental Medicine and Professor of Microbiology at Boston University School of Medicine discovered recently a novel, evolutionarily conserved mechanism for the regulation of gene expression. The study describing this work titled, "Mpk1 MAPK Association with the Paf1 Complex Blocks Sen1-Mediated Premature Transcription Termination," appears in the March 4 issue of Cell. Normal cell growth, embryonic development, and responses to stress, require proper spatial ...

Can you predict your mate will cheat by their voice?

2011-03-05
When choosing a partner, women believe the lower the man's voice, the more likely he's going to cheat. Conversely, men think a woman with a higher voice is more likely to be unfaithful, researchers have found. The study, published in the latest edition of the online journal Evolutionary Psychology is the first to examine the link between voice pitch and perceived infidelity and offers insight into the evolution of the human voice and how we choose our mates. "In terms of sexual strategy, we found that men and women will use voice pitch as a warning sign of future betrayal. ...

Report offers framework for evaluating D.C. school reform efforts, along with first impressions

2011-03-05
WASHINGTON — A new report from the National Research Council offers a framework for evaluating the effects of a 2007 reform law on the District of Columbia's public schools. The evaluation program must include systematic yearly public reporting of key data as well as in-depth studies of high-priority issues, such as teacher recruitment and retention, the report says. As part of the evaluation program, the Mayor's Office should produce an annual report to the city on the status of the public schools, including an analysis of trends and all the underlying data. The evaluation ...

LAST 30 PRESS RELEASES:

Family ties and firm performance: How cousin marriage traditions shape informal businesses in Africa

Novel flu vaccine adjuvant improves protection against influenza viruses, study finds

Manipulation of light at the nanoscale helps advance biosensing

New mechanism discovered in ovarian cancer peritoneal metastasis: YWHAB restriction drives stemness and chemoresistance

New study links blood metabolites and immune cells to increased risk of urolithiasis

Pyruvate identified as a promising therapeutic agent for ulcerative colitis by targeting cytosolic phospholipase A2

New insights into the clinical impact of IKBKG mutations: Understanding the mechanisms behind rare immunodeficiency syndromes

Displays, imaging and sensing: New blue fluorophore breaks efficiency records in both solids and solutions

Sugar, the hidden thermostat in plants

Personality can explain why some CEOs earn higher salaries

This puzzle game shows kids how they’re smarter than AI

Study suggests remembrances of dead played role in rise of architecture in Andean region

Brain stimulation can boost math learning in people with weaker neural connections

Inhibiting enzyme could halt cell death in Parkinson’s disease, study finds

Neurotechnology reverses biological disadvantage in maths learning

UNDER EMBARGO: Neurotechnology reverses biological disadvantage in maths learning

Scientists target ‘molecular machine’ in the war against antimicrobial resistance

Extending classical CNOP method for deep-learning atmospheric and oceanic forecasting

Aston University research: Parents should encourage structure and independence around food to support children’s healthy eating

Thunderstorms are a major driver of tree death in tropical forests

Danforth Plant Science Center adds two new faculty members

Robotic eyes mimic human vision for superfast response to extreme lighting

Racial inequities and access to COVID-19 treatment

Residential segregation and lung cancer risk in African American adults

Scientists wipe out aggressive brain cancer tumors by targeting cellular ‘motors’

Capturability distinction analysis of continuous and pulsed guidance laws

CHEST expands Bridging Specialties Initiative to include NTM disease and bronchiectasis on World Bronchiectasis Day

Exposure to air pollution may cause heart damage

SwRI, UTSA selected by NASA to test electrolyzer technology aboard parabolic flight

Prebiotics might be a factor in preventing or treating issues caused by low brain GABA

[Press-News.org] Zooming in on the weapons of Salmonella