Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Small talk – The gabfest of microbial communication

30.04.2003


ONR-sponsored Bonnie Bassler looks at bacterial communication

She thinks they’re everywhere. What’s more, she thinks they talk to each other.
But don’t snicker…ONR-sponsored Bonnie Bassler won a MacArthur Foundation ’genius award’ last year for her research on how some of the most deadly microbes we know – cholera, plague, TB, just to mention a few – communicate surprisingly well.


In her Princeton Lab, Bassler (and the rest of the microbiology community) calls it ’quorum sensing.’ When microbes sense that there’s more than just a few of them around (i.e., increases in cell population density), a sort of gabfest starts, and this can lead to the production of toxins that make us very, very sick.

Microscopic organisms must rely on simple, yet complex (depending on how you look at it) means of communication. "Quorum sensing" was first discovered in two bacteria in the belly of the cuttlefish: Vibrio harveyi and Vibrio fischeri. These fellows emit light in response to increases in cell population density – they release and detect hormone-like molecules called autoinducers that accumulate in the surrounding aquatic environment as the bacterial cell density increases.

Working with Vibrio harveyi and Vibrio fischeri Bassler and her colleagues discovered that bacteria express a gene called LuxI, which results in the release of special chemicals she calls autoinducers (AI-1) which, in turn, bind to proteins called LuxR on other bacteria nearby. Once the LuxR is activated, a multitude of cellular effects, varying by species, is performed. This is especially useful to bacteria in sensing the size of their colony. Each bacterium constantly emits AI-1, as the number of individuals in a colony grows, so does the amount of AI-1 surrounding them. Once the colony reaches a certain size, a quorum, the amount of LuxI is sufficient to trigger cellular effects. Scores of bacteria species use this quorum sensing every day.

But why would bacteria care how many others are around them? Bacteria are the biggest biomass on the planet, and in order for them to be as successful as they are, they must work together for the good of the colony. Each bacterium is not a ’lone soldier’ so to speak, rather it waits until a sufficient number of others are around to begin producing toxins, or emitting light, etc. "Bacteria can talk to each other," Bassler says. "They take a roll call and the language is LuxI/LuxR."

Bassler’s research is important in the fight against virulent strains of bacteria. Her team’s current work is to find a way to disrupt this LuxI/LuxR language so the bacteria are deafened to the calls of their compatriots. Bassler and colleagues recently showed that cholera bacteria use quorum sensing to regulate their virulence.

"If a bacterium thinks it is alone in the world, it won’t produce the toxins which make us sick, or, for that matter, make biofilms which lead to ship hull fouling" says ONR sponsor Dr. Linda Chrisey. It’s only when many of them get together, and decide to "turn on", that the bacteria become a problem. "Since a disruption-type of therapy wouldn’t kill the bacteria, resistance to these new drugs would be slow to develop. This research has enormous potential for rapid, accurate pathogen sensing and novel antibiotic strategies."

Harmless bacteria can also be used to sense lethal strains. V. harveyi, which uses the LuxI/LuxR language to decide when to glow, can sense LuxI from other harmful species. "These guys can sense the ’who’s who’ of pathogenic bacteria, like anthrax, staph, strep, E. coli, and salmonella," Bassler says. "When V. harveyi senses the AI from other species, it glows brilliantly. In fact, many diverse bacterial functions such as virulence factor production, conjugative DNA transfer, symbiosis, and antibiotic production are now known to be controlled by quorum sensing."

Ah… spoken like a true genius.

Ed Walsh | EurekAlert!
Further information:
http://www.onr.navy.mil/

More articles from Life Sciences:

nachricht Biophysicists reveal how optogenetic tool works
29.05.2020 | Moscow Institute of Physics and Technology

nachricht Mapping immune cells in brain tumors
29.05.2020 | University of Zurich

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Biotechnology: Triggered by light, a novel way to switch on an enzyme

In living cells, enzymes drive biochemical metabolic processes enabling reactions to take place efficiently. It is this very ability which allows them to be used as catalysts in biotechnology, for example to create chemical products such as pharmaceutics. Researchers now identified an enzyme that, when illuminated with blue light, becomes catalytically active and initiates a reaction that was previously unknown in enzymatics. The study was published in "Nature Communications".

Enzymes: they are the central drivers for biochemical metabolic processes in every living cell, enabling reactions to take place efficiently. It is this very...

Im Focus: New double-contrast technique picks up small tumors on MRI

Early detection of tumors is extremely important in treating cancer. A new technique developed by researchers at the University of California, Davis offers a significant advance in using magnetic resonance imaging to pick out even very small tumors from normal tissue. The work is published May 25 in the journal Nature Nanotechnology.

researchers at the University of California, Davis offers a significant advance in using magnetic resonance imaging to pick out even very small tumors from...

Im Focus: I-call - When microimplants communicate with each other / Innovation driver digitization - "Smart Health“

Microelectronics as a key technology enables numerous innovations in the field of intelligent medical technology. The Fraunhofer Institute for Biomedical Engineering IBMT coordinates the BMBF cooperative project "I-call" realizing the first electronic system for ultrasound-based, safe and interference-resistant data transmission between implants in the human body.

When microelectronic systems are used for medical applications, they have to meet high requirements in terms of biocompatibility, reliability, energy...

Im Focus: When predictions of theoretical chemists become reality

Thomas Heine, Professor of Theoretical Chemistry at TU Dresden, together with his team, first predicted a topological 2D polymer in 2019. Only one year later, an international team led by Italian researchers was able to synthesize these materials and experimentally prove their topological properties. For the renowned journal Nature Materials, this was the occasion to invite Thomas Heine to a News and Views article, which was published this week. Under the title "Making 2D Topological Polymers a reality" Prof. Heine describes how his theory became a reality.

Ultrathin materials are extremely interesting as building blocks for next generation nano electronic devices, as it is much easier to make circuits and other...

Im Focus: Rolling into the deep

Scientists took a leukocyte as the blueprint and developed a microrobot that has the size, shape and moving capabilities of a white blood cell. Simulating a blood vessel in a laboratory setting, they succeeded in magnetically navigating the ball-shaped microroller through this dynamic and dense environment. The drug-delivery vehicle withstood the simulated blood flow, pushing the developments in targeted drug delivery a step further: inside the body, there is no better access route to all tissues and organs than the circulatory system. A robot that could actually travel through this finely woven web would revolutionize the minimally-invasive treatment of illnesses.

A team of scientists from the Max Planck Institute for Intelligent Systems (MPI-IS) in Stuttgart invented a tiny microrobot that resembles a white blood cell...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Dresden Nexus Conference 2020: Same Time, Virtual Format, Registration Opened

19.05.2020 | Event News

Aachen Machine Tool Colloquium AWK'21 will take place on June 10 and 11, 2021

07.04.2020 | Event News

International Coral Reef Symposium in Bremen Postponed by a Year

06.04.2020 | Event News

 
Latest News

Black nitrogen: Bayreuth researchers discover new high-pressure material and solve a puzzle of the periodic table

29.05.2020 | Materials Sciences

Argonne researchers create active material out of microscopic spinning particles

29.05.2020 | Materials Sciences

Smart windows that self-illuminate on rainy days

29.05.2020 | Power and Electrical Engineering

VideoLinks
Science & Research
Overview of more VideoLinks >>>