Featured Research

from universities, journals, and other organizations

Mortal chemical combat typifies the world of bacteria

Date:
November 18, 2010
Source:
University of North Carolina School of Medicine
Summary:
New complexities in the close chemical combat waged among bacteria have been detailed. The findings may have implications for human health and survival.

Gram-negative Bordetella bronchiseptica coccobacilli bacteria.
Credit: Janice Haney Carr

Like all organisms, bacteria must compete for resources to survive, even if it means a fight to the death.

New research led by scientists from the University of North Carolina at Chapel Hill School of Medicine and the University of California, Santa Barbara, describes new complexities in the close chemical combat waged among bacteria.

And the findings from this microscopic war zone may have implications for human health and survival.

"It has been known for a long time that bacteria can produce toxins that they release into their surroundings that can kill other bacteria, sort of like throwing hand grenades at enemies," said Peggy A. Cotter, PhD, associate professor in the microbiology and immunology department at UNC. "Our data suggests that the situation is far more complex that we thought."

Cotter points out that it was in David A. Low's lab at U.C. Santa Barbara, where the discovery was made that bacteria can also produce proteins on their surface that inhibit the growth and end the life of other bacteria upon contact.

"So it appears that some bacteria participate in 'man to man' (or 'bacteria to bacteria') combat using poison-tipped swords," Cotter said. "What we have discovered is that each bacterium can have a different poison at the tip of their sword. For each poison, there is a specific protective (immunity) protein that the bacteria also make so that they don't kill themselves and are not killed by other members of their same 'family'."

The new research by senior co-authors Cotter and Low and others appear on-line November 18, 2010 in the journal Nature.

As to "swords," the metaphor lives close to reality. Bacteria use proteins to interact with a host, including disease-causing bacteria, such as Bordetella pertussis, the cause of whooping cough and Burkholderia pseudomallei, found in soil throughout Southeast Asia and a cause of a frequently fatal tropic disease.

In these and other gram-negative bacteria, large proteins appear as rods on the surface of cells. "In the soil or in humans, different bacteria bump into each other all the time and bump into their own 'family,' too. They have to touch each other and recognize each other and then one can inhibit the growth of the other, non-family, bacteria." Cotter said.

According to the UNC scientist, this system may represent a primitive form of kin selection, whereby organisms kill organisms that are genetically different but not those that are closely related.

"As an additional twist, we have found that some bacteria can have two or three (or possibly more) systems. Our data suggest that these bacteria will be protected from killing by bacteria that produce any of three types of poison swords and they will be able to kill other bacteria that lack at least one of those types of immunity proteins."

Moreover, there's evidence here that these bacteria acquire these additional systems by horizontal gene transfer from other bacteria. "In other words, it seems that they may be able to kill their enemy and then steal the poison-tipped sword and protective (immunity) protein from the dead enemy, increasing their own repertoire of weapons."

By teasing out the genetics of these bacterial close combat mysteries, it may someday be possible to "engineer an organism, a non-pathogenic variant, and by putting it out in the environment, such as soil, you can potentially get rid of other pathogens, "Cotter said. "Or you could decontaminate an area, if the new knowledge is applied to biodefense."


Story Source:

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


Journal Reference:

  1. Stephanie K. Aoki, Elie J. Diner, Claire t’Kint de Roodenbeke, Brandt R. Burgess, Stephen J. Poole, Bruce A. Braaten, Allison M. Jones, Julia S. Webb, Christopher S. Hayes, Peggy A. Cotter, David A. Low. A widespread family of polymorphic contact-dependent toxin delivery systems in bacteria. Nature, 2010; 468 (7322): 439 DOI: 10.1038/nature09490

Cite This Page:

University of North Carolina School of Medicine. "Mortal chemical combat typifies the world of bacteria." ScienceDaily. ScienceDaily, 18 November 2010. <www.sciencedaily.com/releases/2010/11/101117141430.htm>.
University of North Carolina School of Medicine. (2010, November 18). Mortal chemical combat typifies the world of bacteria. ScienceDaily. Retrieved July 31, 2014 from www.sciencedaily.com/releases/2010/11/101117141430.htm
University of North Carolina School of Medicine. "Mortal chemical combat typifies the world of bacteria." ScienceDaily. www.sciencedaily.com/releases/2010/11/101117141430.htm (accessed July 31, 2014).

Share This




More Plants & Animals News

Thursday, July 31, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Visitors Feel Part of the Pack at Wolf Preserve

Visitors Feel Part of the Pack at Wolf Preserve

AP (July 31, 2014) Seacrest Wolf Preserve on the northern Florida panhandle allows more than 10,000 visitors each year to get up close and personal with Arctic and British Columbian Wolves. (July 31) Video provided by AP
Powered by NewsLook.com
Florida Panther Rebound Upsets Ranchers

Florida Panther Rebound Upsets Ranchers

AP (July 31, 2014) With Florida's panther population rebounding, some ranchers complain the protected predators are once again killing their calves. (July 31) Video provided by AP
Powered by NewsLook.com
Dangerous Bacteria Kills One in Florida

Dangerous Bacteria Kills One in Florida

AP (July 31, 2014) Sarasota County, Florida health officials have issued a warning against eating raw oysters and exposing open wounds to coastal and inland waters after a dangerous bacteria killed one person and made another sick. (July 31) Video provided by AP
Powered by NewsLook.com
Raw: Thousands Flocking to German Crop Circle

Raw: Thousands Flocking to German Crop Circle

AP (July 30, 2014) Thousands of people are trekking to a Bavarian farmer's field to check out a mysterious set of crop circles. (July 30) Video provided by AP
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