Bacterial attack strategy uses special delivery of toxic proteins

Pseudomonas aeruginosa targets opponents' cell walls and immunizes itself against its own weapons

2011-07-22

(Press-News.org) When competing for food and resources, bacteria employ elaborate strategies to keep rival cells at bay. Scientists have now identified a pathway that allows disease-causing bacteria to attack other bacterial cells by breaking down their cell wall.

Pseudomonas aeruginosa is a type of bacteria readily found in everyday environments. It easily forms colonies in a wide variety of settings, including medical devices, body organs and skin wounds. This allows it to cause disease and act as a major pathogen, particularly in hospitals.

Research led by Joseph Mougous, assistant professor of microbiology at the University of Washington in Seattle, provides new insight into how P. aeruginosa acts as a master colonizer and maintains a competitive advantage over other bacteria. The study, which will be published in the July 21 issue of the journal Nature, describes how P. aeruginosa uses a specialized secretion system--the type VI secretion system--to deliver toxic proteins to recipient opponent bacteria. These proteins break down a structural protein known as peptoglycan, which the authors describe as "an Achilles heel of bacteria." Degrading this target in turn causes the breakdown of the protective cell wall of competitor bacteria. Furthermore, P. aeruginosa protects itself from this attack by using specific, strategically localized immunity proteins that counteract the effects of the toxic proteins it secretes.

This discovery not only sheds light on P. aeruginosa's pathogenic success, but is also interesting from an evolutionary perspective as it highlights the functional similarity between the bacterial type VI secretion system and viruses that infect bacteria, or bacteriophages.

INFORMATION:

This research was supported by the National Institutes of Health, the European Commission within the DIVINOCELL programme, and the National Science Foundation.

For more information regarding this research, view the video sound bites of Alistair Russell, lead author of the research manuscript and National Science Foundation Graduate Research Fellow at the University of Washington.

[Attachments] See images for this press release:

ELSE PRESS RELEASES FROM THIS DATE:

Blue collar workers work longer and in worse health than their white collar bosses

2011-07-22

While more Americans are working past age 65 by choice, a growing segment of the population must continue to work well into their sixties out of financial necessity. Research conducted by the Columbia University's Mailman School of Public Health and the University of Miami Miller School of Medicine looked at aging, social class and labor force participation rates to illustrate the challenges that lower income workers face in the global marketplace. The study used the burden of arthritis to examine these connections because 49 million U.S. adults have arthritis, and 21 ...

Chronic pain in homeless people not managed well: Study

2011-07-22

TORONTO, Ont., July 21, 2011—Chronic pain is not managed well in the general population and it's an even greater challenge for homeless people, according to new research by St. Michael's Hospital. Twenty-five per cent of Canadians say they have continuous or intermittent chronic pain lasting six months or more. The number is likely to be even higher among homeless people, in part due to frequent injuries. Of the 152 residents of homeless shelters with chronic pain studied by Dr. Stephen Hwang, more than one-third (37 per cent) had Chronic Pain Grade IV, the highest ...

Nanotechnology for water filter

2011-07-22

This release is available in German. Nanotechnology has developed tremendously in the past decade and was able to create many new materials with a vast range of potential applications. Carbon nanotubes are an example of these new materials and consist of cylindrical molecules of carbon with diameters of a few nanometers – one nanometer is one millionth of a millimeter. Carbon nanotubes possess exceptional electronic, mechanical and chemical properties, for example they can be used to clean polluted water. Scientists of the University of Vienna had recently published ...

Fingerprinting fugitive dust

2011-07-22

This release is available in Spanish. Each community of soil microbes has a unique fingerprint that can potentially be used to track soil back to its source, right down to whether it came from dust from a rural road or from a farm field, according to a U.S. Department of Agriculture (USDA) soil scientist. Ann Kennedy, at the Agricultural Research Service (ARS) Land Management and Water Conservation Research Unit in Pullman, Wash., studies the biological properties of soils that affect wind erosion. She analyses the soil for the fatty acid or lipid content from the community ...

Study: Subsidizing wages at long-term care facilities would cut turnover

2011-07-22

CHAMPAIGN, Ill. — Subsidizing the wages of caregivers at group homes would likely reduce worker turnover rates and help contain costs at long-term care facilities, according to new University of Illinois research. Elizabeth T. Powers, a professor of economics and faculty member of the Institute of Government and Public Affairs at Illinois, says that a government-sponsored wage-subsidy program could reduce the churn of low-wage caregivers through group homes by one-third. "High rates of worker turnover have costs, and there aren't a lot incentives for the agencies that ...

Stronger social safety net leads to decrease in stress, childhood obesity

2011-07-22

CHAMPAIGN, Ill. — Social safety net programs that reduce psychosocial stressors for low-income families also ultimately lead to a reduction in childhood obesity, according to research by a University of Illinois economist who studies the efficacy of food assistance programs on public health. Craig Gundersen, a professor of agricultural and consumer economics at Illinois, says food and exercise alone are not to blame for the extent of obesity among children in the United States. Psychosocial factors, such as stressors brought about by uncertainty about the economy, income ...

Executive pay reform unlikely to reduce systemic risk in economy

2011-07-22

CHAMPAIGN, Ill. — Reforms aimed at curbing executive compensation will likely have little effect on reducing systemic risk in the financial system, and they may even have unintended consequences for the freedom to contract, according to a University of Illinois expert in business law and corporate finance. In a paper published in the Ohio State Entrepreneurial Business Law Journal, law professor Christine Hurt argues that giving regulators unprecedented power to prohibit certain types of private compensation under the guise of minimizing systemic risk in the financial ...

Study: Regulatory hurdles hinder biofuels market

2011-07-22

CHAMPAIGN, Ill. — Regulatory hurdles abound for the successful commercialization of emerging liquid biofuels, which hold the promise of enhancing U.S. energy security, reducing greenhouse gas emissions and serving as a driver for rural economic development, according to new U. of I. research. In the study, University of Illinois law professor Jay P. Kesan and Timothy A. Slating, a regulatory associate with the University of Illinois Energy Biosciences Institute, argue that regulatory innovations are needed to keep pace with technological innovations in the biofuels industry. "Getting ...

Chance favors the concentration of wealth, U of M study shows

2011-07-22

Most of our society's wealth is invested in businesses or other ventures that may or may not pan out. Thus, chance plays a role in where the wealth of a society will end up. But does chance favor the concentration of wealth in the hands of a few, or does it tend to level the playing field? Three University of Minnesota researchers have built a simplified model that isolates the effects of chance and found that it consistently pushes wealth into the hands of a few, ever-richer people. The study, "Entrepreneurs, chance, and the deterministic concentration of wealth," ...

NASA sees Tropical Storms Bret and now Cindy frolic in North Atlantic

2011-07-22

Two tropical storms are now in the open waters of the North Atlantic: Bret and Cindy. Both were captured on one image from NASA today. Both storms are hundreds of miles to the east-northeast of Bermuda and pose no threat to land areas. NASA's GOES Project issued an infrared image of both Bret and Cindy today from the GOES-13 satellite, which is operated by NOAA. The NASA GOES Project is housed at NASA's Goddard Space Flight Center in Greenbelt, Md. and uses GOES-13 data from NOAA to create images and animations. The image was captured at 0845 UTC (4:45 a.m. EDT) and shows ...

LAST 30 PRESS RELEASES:

‘Teen-friendly’ mindfulness therapy aims to help combat depression among teenagers

Innovative risk score accurately calculates which kidney transplant candidates are also at risk for heart attack or stroke, new study finds

Amid record year for dengue infections, new study finds climate change responsible for 19% of today’s rising dengue burden

New study finds air pollution increases inflammation primarily in patients with heart disease

AI finds undiagnosed liver disease in early stages

The American Society of Tropical Medicine and Hygiene and the Bill & Melinda Gates Foundation announce new research fellowship in malaria genomics in honor of professor Dominic Kwiatkowski