Featured Research

from universities, journals, and other organizations

How bacterial community evolves to survive

Date:
May 17, 2010
Source:
University of Cincinnati Academic Health Center
Summary:
An international team of researchers has shown how a bacterial community evolves to survive hostile host defenses in the body.

New research shows how a bacterial community evolves to survive hostile host defenses in the body.
Credit: Image courtesy of University of Cincinnati Academic Health Center

An international team led by a University of Cincinnati (UC) researcher has shown how a bacterial community evolves to survive hostile host defenses in the body.

Related Articles


The team, led by Malak Kotb, PhD, chair of UC's of molecular genetics, biochemistry and microbiology department, analyzed the evolution over time of the community structure of Group A streptococcus (also known as GAS or Strep A), a bacterium often found in the throat or on the skin. It can cause many human diseases, ranging from strep throat to debilitating and often deadly diseases of the heart, skin, kidney and brain.

In the 1980s, hypervirulent strains of the Strep A bacteria emerged, including necrotizing fasciitis (commonly known as the flesh-eating disease), an invasive GAS that is an infection of the deeper layers of skin and subcutaneous tissue. About 9,000 to 11,500 cases of invasive GAS disease -- in which bacteria get into parts of the body where bacteria usually are not found -- occur each year in the United States, resulting in 1,000 to 1,800 deaths annually, according to the Centers for Disease Control and Prevention (CDC). In Greater Cincinnati, there have been several highly publicized cases associated with death or amputation.

The research team's findings appear in PLoS ONE, an open-access online journal of peer-reviewed articles.

"This is the first organized attempt to capture the dynamics of bacterial evolution in live species and to discover molecular events that are associated with stark changes in the demographics of the bacterial community as they sacrifice the majority of their members and select the fittest ones to survive host defenses," says Kotb, who is also director of the Midwest Center for Emerging Infectious Diseases (MI-CEID).

Researchers found that as dominant members of the population surrendered to host immune defenses, they were replaced by a hyperaggressive, mutant minority population that thrived and took over the abandoned community to become the new majority.

Using a mouse model, the team monitored evolutionary changes in the bacterial community as it faced different environmental factors and attempted to adapt to different host niches. The data confirmed that the bacterial community is mixed and that under certain conditions different populations can take over the community.

"What we perceive as a single bacterial colony is in fact a mixture of subpopulations whose members play different roles to achieve virulence," says study author Ramy Aziz, PhD, of Cairo University's department of microbiology and immunology. "The survivors, it turns out, have the final word."

Authors call the study a first step toward exploring the sociomicrobiology of invasive Group A streptococci within a living organism. They plan to follow with single cell studies of bacteria associated with immune cells to further dissect the different roles played by members of the same bacterial community.

The study was supported by grants from the National Institutes of Health (NIH) National Institute of Allergy and Infectious Diseases (NIAID); the United States Army Medical Research Activity; the Research and Development Office, Medical Research Service, Department of Veterans Affairs; and the National Health and Merit Research Council of Australia.

Cincinnati researchers on the team, in addition to Kotb, included Bruce Aronow, PhD, co-director of the Computational Medicine Center, a collaboration between Cincinnati Children's Hospital Medical Center and the University of Cincinnati; and Rita Kansal, PhD, and Sarah Rowe, members of Kotb's lab at UC.


Story Source:

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


Journal Reference:

  1. Ramy K. Aziz, Rita Kansal, Bruce J. Aronow, William L. Taylor, Sarah L. Rowe, Michael Kubal, Gursharan S. Chhatwal, Mark J. Walker, Malak Kotb, Niyaz Ahmed. Microevolution of Group A Streptococci In Vivo: Capturing Regulatory Networks Engaged in Sociomicrobiology, Niche Adaptation, and Hypervirulence. PLoS ONE, 2010; 5 (4): e9798 DOI: 10.1371/journal.pone.0009798

Cite This Page:

University of Cincinnati Academic Health Center. "How bacterial community evolves to survive." ScienceDaily. ScienceDaily, 17 May 2010. <www.sciencedaily.com/releases/2010/05/100512125232.htm>.
University of Cincinnati Academic Health Center. (2010, May 17). How bacterial community evolves to survive. ScienceDaily. Retrieved November 26, 2014 from www.sciencedaily.com/releases/2010/05/100512125232.htm
University of Cincinnati Academic Health Center. "How bacterial community evolves to survive." ScienceDaily. www.sciencedaily.com/releases/2010/05/100512125232.htm (accessed November 26, 2014).

Share This


More From ScienceDaily



More Plants & Animals News

Wednesday, November 26, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Classic Hollywood Memorabilia Goes Under the Hammer

Classic Hollywood Memorabilia Goes Under the Hammer

Reuters - Entertainment Video Online (Nov. 26, 2014) The iconic piano from "Casablanca" and the Cowardly Lion suit from "The Wizard of Oz" fetch millions at auction. Sara Hemrajani reports. Video provided by Reuters
Powered by NewsLook.com
Pet Dogs to Be Used in Anti-Ageing Trial

Pet Dogs to Be Used in Anti-Ageing Trial

Reuters - Innovations Video Online (Nov. 26, 2014) Researchers in the United States are preparing to discover whether a drug commonly used in human organ transplants can extend the lifespan and health quality of pet dogs. Video provided by Reuters
Powered by NewsLook.com
From Popcorn To Vending Snacks: FDA Ups Calorie Count Rules

From Popcorn To Vending Snacks: FDA Ups Calorie Count Rules

Newsy (Nov. 25, 2014) The US FDA is announcing new calorie rules on Tuesday that will require everywhere from theaters to vending machines to include calorie counts. Video provided by Newsy
Powered by NewsLook.com
Feast Your Eyes: Lamb Chop Sent Into Space from UK

Feast Your Eyes: Lamb Chop Sent Into Space from UK

Reuters - Light News Video Online (Nov. 25, 2014) Take a stab at this -- stunt video shows a lamb chop's journey from an east London restaurant over 30 kilometers into space. Rough Cut (no reporter narration). Video provided by Reuters
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


Plants & Animals

Earth & Climate

Fossils & Ruins

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