Featured Research

from universities, journals, and other organizations

Tiny Shock Absorbers Help Bacteria Stick Around Inside The Body

Date:
September 1, 2006
Source:
University of Washington
Summary:
Bacteria have hair-like protrusions with a sticky protein on the tip that lets them cling to surfaces. The coiled, bungee cord-like structure of the protrusions helps the bacteria hang on tightly, even under rough fluid flow inside the body, researchers report in the journal PLoS Biology.

This illustration shows an E. coli bacterium with hair-like fimbriae that bind to molecules on a surface. Some of the fimbriae have uncoiled from one end as fluid flow pulls on the bacterium. The uncoiling and recoiling of the fimbriae, like a nanoscopic Slinky toy, ensures that each fimbria keeps the right amount of force for the finger-trap-like molecules at the tip to stick firmly to the surface even in high and unstable fluid flow.
Credit: Photo illustration by Sheila Luna, ETH Zurich

Bacteria have hair-like protrusions with a sticky protein on the tip that lets them cling to surfaces. The coiled, bungee cord-like structure of the protrusions helps the bacteria hang on tightly, even under rough fluid flow inside the body, researchers report in the journal PLoS Biology.

A group of researchers at the University of Washington in Seattle and ETH Zurich in Switzerland have been studying how the bacterium E. coli attaches to mucous membranes in the body. In their previous research, they explained how the protrusions, known as fimbriae, have an adhesive protein called FimH at their tip that binds in an unusual way to a sugar molecule on a surface.

The FimH-sugar combination makes a "catch bond" that acts like a finger trap, and actually gets stronger as drag force is exerted on a bacterium. Rather than being swept away by fluids moving through the human body, the bacterium grips even more tightly, helping it stick around and form an infection, like those seen in the urinary tract, for instance. The catch bonds release their grip when there is little or no force on the bacteria.

In new research, the scientists have learned that the mechanical properties of the bungee-like fimbriae also play a key role in the tenacity of E. coli clinging to mucousal surfaces. The tiny fiber-like protrusions are made up of interlocking protein segments in a tightly coiled helix shape, like a seven-nanometer-wide Slinky toy. The researchers found that under force, the fimbriae stretch to many times their original length as the protein segments uncoil one by one. If the force on them drops, the fimbriae coils are compressed, keeping tension on the bond between the bacterium and the mucous membrane.

"The fimbriae uncoil and recoil to dampen sudden changes in forces caused by rough and rapidly changing flow conditions," explained study co-author Dr. Viola Vogel, professor in the Department of Materials at ETH Zurich. This process maintains an optimal force required to keep the finger trap-like FimH anchor from breaking loose.

"This system is similar to a set of shock absorbers on your car that dampen turbulent forces caused by bumpy road conditions," added study co-author Dr. Wendy Thomas, assistant professor of bioengineering at the UW.

The researchers found that fimbrial uncoiling and recoiling events balance each other at an intermediate force level that corresponds to the force at which the sticky protein tip forms the most stable bond with the surface. Thus, the mechanical and adhesive features of the system evolved together to help the bacteria persist in tough environments inside a host animal or person.

"Research on these fimbriae uncovers something that's essentially a mechanical nanotechnological device created by nature, and gives us the opportunity to adapt such a system for biotechnological and even other technical uses," said study co-author Dr. Evgeni Sokurenko, associate professor of microbiology at the UW and a principal investigator at the NIH Bioengineering Research Partnership that primarily funded the project. "It also improves our understanding of how to fight bacteria that persist in turbulent environments, like the human urinary tract or intestines."

The research appears in the September issue of PLoS Biology, part of the Public Library of Science, a series of open-access journals available online at http://www.plos.org/. Its authors also include Manu Forero, a graduate student in the Department of Materials at ETH Zurich, and Dr. Olga Yakovenko, senior fellow in bioengineering at the UW.


Story Source:

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


Cite This Page:

University of Washington. "Tiny Shock Absorbers Help Bacteria Stick Around Inside The Body." ScienceDaily. ScienceDaily, 1 September 2006. <www.sciencedaily.com/releases/2006/08/060830075659.htm>.
University of Washington. (2006, September 1). Tiny Shock Absorbers Help Bacteria Stick Around Inside The Body. ScienceDaily. Retrieved July 30, 2014 from www.sciencedaily.com/releases/2006/08/060830075659.htm
University of Washington. "Tiny Shock Absorbers Help Bacteria Stick Around Inside The Body." ScienceDaily. www.sciencedaily.com/releases/2006/08/060830075659.htm (accessed July 30, 2014).

Share This




More Plants & Animals News

Wednesday, July 30, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

In Virginia, the Rise of a New Space Coast

In Virginia, the Rise of a New Space Coast

AP (July 30, 2014) Every summer, tourists make the pilgrimage to Chincoteague Island, Va. to see wild ponies cross the Assateague Channel. But, it's the rockets sending to supplies to the International Space Station that are making this a year-round destination. (July 30) Video provided by AP
Powered by NewsLook.com
Rodents Rampant in Gardens Around Louvre

Rodents Rampant in Gardens Around Louvre

AP (July 29, 2014) Food scraps and other items left on the grounds by picnickers brings unwelcome visitors to the grounds of the world famous and popular Louvre Museum in Paris. (July 29) Video provided by AP
Powered by NewsLook.com
Jane Goodall Warns Great Apes Face Extinction

Jane Goodall Warns Great Apes Face Extinction

AFP (July 29, 2014) The world's great apes face extinction within decades, renowned chimpanzee expert Jane Goodall warned Tuesday in a call to arms to ensure man's closest relatives are not wiped out. Duration: 00:58 Video provided by AFP
Powered by NewsLook.com
How Your Face Can Leave A Good Or Bad First Impression

How Your Face Can Leave A Good Or Bad First Impression

Newsy (July 29, 2014) Researchers have found certain facial features can make us seem more attractive or trustworthy. Video provided by Newsy
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:
from the past week

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