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 Closing the carbon loop
08.12.2016 | University of Pittsburgh

nachricht Newly discovered bacteria-binding protein in the intestine
08.12.2016 | University of Gothenburg

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Closing the carbon loop

08.12.2016 | Life Sciences

Applicability of dynamic facilitation theory to binary hard disk systems

08.12.2016 | Physics and Astronomy

Scientists track chemical and structural evolution of catalytic nanoparticles in 3-D

08.12.2016 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>