(Press-News.org) The bacterial foodborne pathogen, Listeria monocytogenes is the causative agent of listeriosis—a debilitating disease linked with ~2,500 illnesses and more than 500 deaths per annum in the US alone. A characteristic feature of L. monocytogenes is its ability to grow at refrigeration temperatures and in the presence of high concentrations of salt—traditional food preservation techniques, which arrest the growth of most other pathogens.
Work in the Sleator lab has shown that the bacterium protects itself from such stresses by twisting into a protective corkscrew type shape in an effort to reduce its exposure to the stress—in the same way a human might wrap up tight—hugging the core to reduce the effects of the cold.
Furthermore, Sleator and colleagues have identified a single point mutation (out of a total of 3 million or so nucleotides that constitute the entire listerial genome), which dramatically improves the growth of the pathogen in the refrigerator.
The research paper, "A single point mutation in the listerial betL σA-dependent promoter leads to improved osmo- and chill-tolerance and a morphological shift at elevated osmolarity," will be published in the November/December 2013 issue of Bioengineered. It is available open access ahead of press: http://www.landesbioscience.com/journals/bioe/article/24094/
Sleator claims that this mutation represents "a double edged sword;" "from a food safety perspective, a single point mutation with the potential to induce such dramatic shifts in cell growth and survival at low temperatures—making an already dangerous pathogen even more formidable—raises significant food-safety concerns which need to be addressed." However, from a synthetic biology point of view, such a boosted-stress resistance gene represents a useful BioBrick (or building block) for the design of more physiologically robust probiotics or, indeed, plants that are more resistant to cold arid conditions.
###Published by Landes Bioscience since 2010, Bioengineered publishes relevant and high-impact original research with a special focus on genetic engineering that involves the generation of recombinant strains and their metabolic products for beneficial applications in food, medicine, industry, environment and bio-defense. Established in 2002, Landes Bioscience is an Austin, Texas-based publisher of biology research journals and books. For more information on Landes Bioscience, please visit http://www.landesbioscience.com/.
Sleator lab identifies single point mutation in Listeria monocytogenes
2013-03-12
ELSE PRESS RELEASES FROM THIS DATE:
AGU journal highlights - March 12, 2013
2013-03-12
The following highlights summarize research papers that have been recently published in Geophysical Research Letters (GRL), Water Resources Research (WRR), and Journal of Geophysical Research-Biogeosciences, (JGR-G).
In this release:
1. Canadian Arctic glacier melt accelerating, irreversible
2. Eyjafjallajökull's iron-rich ash fertilized North Atlantic Ocean
3. A seismometer in orbit around Earth
4. Distinguishing drought and water scarcity
5. Evaluating the seismic risk of mineral carbon sequestration
6. Tracing nitrate in watersheds
7. Devastating East African ...
Device may lead to quicker, more efficient diagnostics
2013-03-12
UNIVERSITY PARK, Pa. -- A twist on thin-film technology may provide a way to optically detect and analyze multiple substances simultaneously, leading to quicker diagnostics in such industries as health care and homeland security, according to Penn State researchers.
One current optical-sensing technology can launch and guide a single light wave, called a surface-plasmon-polariton wave -- SPP wave -- that travels along the flat interface of the sample to be analyzed and a metal film. The SPP wave is launched by sending a light beam through a prism to the other face of ...
Bitter melon juice prevents pancreatic cancer in mouse models
2013-03-12
A University of Colorado Cancer study published this week in the journal Carcinogenesis shows that bitter melon juice restricts the ability of pancreatic cancer cells to metabolize glucose, thus cutting the cells' energy source and eventually killing them.
"Three years ago researchers showed the effect of bitter melon extract on breast cancer cells only in a Petri dish. This study goes much, much farther. We used the juice – people especially in Asian countries are already consuming it in quantity. We show that it affects the glucose metabolism pathway to restrict energy ...
Steganography is no laughing matter
2013-03-12
Encrypting a message with a strong code is the only safe way to keep your communications secret, but it will be obvious to anyone seeing such a message that the sender is hiding something, regardless of whether they are encrypting their emails for legitimate or illicit purposes. Steganography on the other hand can hide a secret message in plain sight. Often a message is secreted within the binary strings of 0s and 1s in a compressed image or music file format. Prying eyes see only the original image or hear the song, whereas the recipient, knowing that a message is within ...
Found a genetic mutation causing mental retardation very similar to Angelman syndrome in Amish
2013-03-12
Researchers from the research group in growth factors and cell differentiation at IDIBELL and the University of Barcelona (UB) have participated in an international study that has identified the genetic cause of developmental delay observed in Amish individuals in the USA. The research results have been published in the Journal of Medical Genetics.
Amish community
Amish is a religious community known for a simple and traditional style of life and for its reluctance to adopt modern amenities and technologies. The IDIBELL-UB researcher José Luis Rosa explains that "in ...
Earth-sized planets in habitable zones are more common than previously thought
2013-03-12
The number of potentially habitable planets is greater than previously thought, according to a new analysis by a Penn State researcher, and some of those planets are likely lurking around nearby stars.
"We now estimate that if we were to look at 10 of the nearest small stars we would find about four potentially habitable planets, give or take," said Ravi Kopparapu, a post-doctoral researcher in geosciences. "That is a conservative estimate," he added. "There could be more."
Kopparapu detailed his findings in a paper accepted for publication in Astrophysical Journal ...
Stereotyping prime obstacle to women in commercial science
2013-03-12
COLLEGE PARK, Md. - Female professors are almost 50 percent less likely than their male counterparts to be invited to join corporate scientific advisory boards (SABs) and start new companies mainly because of gender stereotyping, says University of Maryland researcher Waverly Ding, an assistant professor of management at the Robert H. Smith School of Business.
Beliefs that women lack leadership and business savvy, and are not capable of helping new ventures attract investment, block their advancement in these areas, she says.
Ding, with co-authors Fiona Murray of MIT ...
Autistic children may be at greater risk of suicide ideation and attempts
2013-03-12
Children with an autism spectrum disorder may be at greater risk for contemplating suicide or attempting suicide than children without autism, according to Penn State College of Medicine researchers.
"We were looking at suicidal ideation and suicide attempts among children with autism versus those that didn't have autism," said Angela Gorman, assistant professor of child psychiatry, Penn State College of Medicine. "What we found is that there were some risk factors that were much more greatly associated with suicidal ideation and suicide attempts than others."
The ...
Digital records could expose intimate details and personality traits of millions
2013-03-12
New research, published today in the journal PNAS, shows that surprisingly accurate estimates of Facebook users' race, age, IQ, sexuality, personality, substance use and political views can be inferred from automated analysis of only their Facebook Likes - information currently publicly available by default.
In the study, researchers describe Facebook Likes as a "generic class" of digital record - similar to web search queries and browsing histories - and suggest that such techniques could be used to extract sensitive information for almost anyone regularly online.
Researchers ...
Less sleep leads to more eating and more weight gain, according to new CU-Boulder study
2013-03-12
Sleeping just five hours a night over a workweek and having unlimited access to food caused participants in a new study led by the University of Colorado Boulder to gain nearly two pounds of weight.
The study, performed in collaboration with the CU Anschutz Medical Campus, suggests that sufficient sleep could help battle the obesity epidemic.
"I don't think extra sleep by itself is going to lead to weight loss," said Kenneth Wright, director of CU-Boulder's Sleep and Chronobiology Laboratory, which led the study. "Problems with weight gain and obesity are much more ...