Featured Research

from universities, journals, and other organizations

MSU Scientists Eavesdrop On Bacterial "Talk"

Date:
April 13, 1998
Source:
Montana State University
Summary:
Bacteria speak a chemical language, and scientists at Montana State University and elsewhere have reported discovering the first few words that govern the growth of bacteria in sticky clusters called biofilms.

by Annette Trinity-Stevens, MSU Research Editor

Related Articles


BOZEMAN, MT -- If bacteria could talk, their conversations might go something like this:

"Stay with us , in this nice place, and make slime or we'll all float off and starve to death." Or, "It's too crowded here. Let's colonize somewhere else."

Bacteria, in fact, do speak a chemical language, and scientists at Montana State University and elsewhere have reported discovering the first few words that govern the growth of bacteria in sticky clusters called biofilms.

The group has published its findings in the April 10 issue of the journal Science . The scientists are David Davies and William Costerton at MSU; Matthew Parsek and Pete Greenberg at the University of Iowa; and James Pearson and Barbara Iglewski at the University of Rochester, New York.

Although not a household word, biofilms are an everyday occurrence, especially in industrial and some medical settings. They clog pipes and foul the hulls of ships. They can create chronic infections in catheters and artificial valves and joints. They may be responsible for ear infections in youngsters. And it's been known for a long time that they rot your teeth.

With today's report, scientists have begun talking cautiously about controlling biofilms not with toxic biocides and antibiotics but by disrupting their own natural messaging system.

"In general, the idea is that we have discovered that bacterial behavior can be modified chemically," said David Davies, the paper's lead author. "These chemicals come from the bacteria themselves."

But first, a bit about bacterial habits. Almost since the time of Louis Pasteur, scientists have thought about and studied bacteria as individual cells floating freely through the bloodstream or in saliva or in a creek.

But most bacteria don't live this planktonic lifestyle. Most live stuck on surfaces in clusters held together by a sticky, gelatinous matrix. These communities are called biofilms. If you've ever slipped on a rock in a stream, you've met a biofilm. When looking through a microscope, scientists have described biofilm communities as elegant arrays of channels and spires.

Several years ago, Davies and MSU microbiologist Gill Geesey learned that the planktonic bacteria throw some kind of genetic switch when they hit a surface, which is their cue to form a biofilm. When they break away from the colony they undergo another biochemical change and revert back to the planktonic, free floating type.

"But there still was one unanswerable question: How could they have such a complex [biofilm] structure without cell-cell signaling," said Bill Costerton, who heads the MSU Center for Biofilm Engineering.

Today's report of cell-cell signaling represents the first words in what may be a large chemical vocabulary dictating how bacteria do what they do in biofilms and why. The paper is the first to report on bacterial communication in biofilms, said Davies, although bacterial communication in other settings, like the kind that produces light in a flashlight fish, was uncovered in the 1970s.

"We now know the words for biofilm formation and for the destruction of biofilms," Davies said. He suspects there also are words to turn on or off specific feeding mechanisms, to accelerate or slow down growth or to make specific enzymes that degrade toxic chemicals.

Davies zeroed in on two chemicals, called homoserine lactones, in a common biofilm maker called P. aeruginosa. P. aeruginosa is the No. 1 cause of hospital acquired infections, the chief organism in burn and open-wound infections and a key player in infections in cystic fibrosis patients, according to Davies.

The bacteria are excreting homoserine lactones all the time, but when enough bacteria gather, something called quorum sensing occurs. The homoserine lactones start to diffuse back into the cells and trigger genetic changes within the bacterium. The bacterium starts making slime and a biofilm results. The signalling process takes about 15 minutes, said Davies.

When working with P. aeruginosa that couldn't make this quorum-sensing chemical, Davies could grow only wimpy biofilms. They lacked the complex and resilient slime structure that characterizes a healthy bacterial community.

"This shows that the biofilms we all know and love are determined by the presence of these molecules," Davies said. "If we can knock out the ability to communicate we can disperse the biofilm."

Costerton said the discovery of communication molecules in biofilms extends into the bacterial world what's already known about the role of signaling molecules such as pheromones and hormones in the animal world.

"We could get quite subtle in our approach to bacteria," he said. "We're used to killing them. Now perhaps we could just disrupt or manipulate them."

An official from the National Science Foundation (NSF), which funds the MSU biofilm center, called the discovery "an exciting event."

"We're on the brink of a brand new technology," Fred Betz, an NSF program officer, said recently after hearing Costerton and Davies talk about their work. "It may be simple. It may be complex. But that's the next step."

The agency has begun funding the next step--the development of chemical messages that would confuse the bacteria and usher in a new way of treating bacterial infections, for example. The MSU biofilm center and the Center for Marine Biofouling and Bioinnovation at the University of New South Wales, Australia, are collaborating on the project.

"It's all still theoretical," cautions Davies. "But this is the area we are inexorably marching toward with this kind of research."


Story Source:

The above story is based on materials provided by Montana State University. Note: Materials may be edited for content and length.


Cite This Page:

Montana State University. "MSU Scientists Eavesdrop On Bacterial "Talk"." ScienceDaily. ScienceDaily, 13 April 1998. <www.sciencedaily.com/releases/1998/04/980413000709.htm>.
Montana State University. (1998, April 13). MSU Scientists Eavesdrop On Bacterial "Talk". ScienceDaily. Retrieved December 19, 2014 from www.sciencedaily.com/releases/1998/04/980413000709.htm
Montana State University. "MSU Scientists Eavesdrop On Bacterial "Talk"." ScienceDaily. www.sciencedaily.com/releases/1998/04/980413000709.htm (accessed December 19, 2014).

Share This


More From ScienceDaily



More Health & Medicine News

Friday, December 19, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

The Best Tips to Curb Holiday Carbs

The Best Tips to Curb Holiday Carbs

Buzz60 (Dec. 19, 2014) It's hard to resist those delicious but fattening carbs we all crave during the winter months, but there are some ways to stay satisfied without consuming the extra calories. Vanessa Freeman (@VanessaFreeTV) has the details. Video provided by Buzz60
Powered by NewsLook.com
Sierra Leone Bikers Spread the Message to Fight Ebola

Sierra Leone Bikers Spread the Message to Fight Ebola

AFP (Dec. 19, 2014) More than 100 motorcyclists hit the road to spread awareness messages about Ebola. Nearly 7,000 people have now died from the virus, almost all of them in west Africa, according to the World Health Organization. Video provided by AFP
Powered by NewsLook.com
Researchers Test Colombian Village With High Alzheimer's Rates

Researchers Test Colombian Village With High Alzheimer's Rates

AFP (Dec. 19, 2014) In Yarumal, a village in N. Colombia, Alzheimer's has ravaged a disproportionately large number of families. A genetic "curse" that may pave the way for research on how to treat the disease that claims a new victim every four seconds. Duration: 02:42 Video provided by AFP
Powered by NewsLook.com
Double-Amputee Becomes First To Move Two Prosthetic Arms With His Mind

Double-Amputee Becomes First To Move Two Prosthetic Arms With His Mind

Buzz60 (Dec. 19, 2014) A double-amputee makes history by becoming the first person to wear and operate two prosthetic arms using only his mind. Jen Markham has the story. Video provided by Buzz60
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins