Featured Research

from universities, journals, and other organizations

New light shed on key bacterial immune system

Date:
April 7, 2014
Source:
University of Otago
Summary:
New insights into a surprisingly flexible immune system present in bacteria for combating viruses and other foreign DNA invaders has been revealed by researchers. The findings demonstrate that some bacterial immune systems are much more robust and responsive than previously thought, and have implications for improving our understanding of bacterial evolution, including the spread of antibiotic resistance genes.

Artist's illustration of microbes (stock image). Viral infections of bacteria exert a powerful yet invisible effect on the entire planet, says Dr Fineran. "Their silent but vast and ongoing war underpins everything from how global nutrient cycles -- which rely on bacteria to produce half of Earth's biomass -- operate, to how human pathogens evolve," he says.
Credit: James Thew / Fotolia

New insights into a surprisingly flexible immune system present in bacteria for combating viruses and other foreign DNA invaders have been revealed by researchers from New Zealand's University of Otago and the Netherlands.

Related Articles


A team led by Dr Peter Fineran of the Department of Microbiology and Immunology are studying the genetic basis of adaptive immunity in bacteria that cause potato 'soft rot' and in E. coli bacteria. Through their recent collaboration they have found that these bacterial immune systems are much more robust and responsive than previously thought.

Their latest findings, which appear in the leading US journal PNAS, have implications for improving our understanding of bacterial evolution, including the spread of antibiotic resistance genes.

The researchers are investigating an adaptive immune system, termed CRISPR-Cas, which is found in half of all bacterial species and in almost all single-celled microbes in the archaea domain.

CRISPR-Cas's role in providing immunity was only discovered in the past decade. The system creates a genetic memory of specific past infections by viruses and plasmids, which are small mobile DNA molecules that can move between organisms.

Dr Fineran says the system steals samples of the invader's genetic material and stores them in a memory bank so it can immediately recognize future exposures and neutralize the attack. It can store up to 600 samples and can also pass on these memories to subsequent generations of bacteria.

It had been thought that the system had an Achilles heel because invaders that had acquired too many mutations could no longer be recognized as they did not match the stored sample closely enough.

"What we have now discovered is that while the viruses and plasmids can evade direct recognition by acquiring multiple mutations, the system is primed to quickly generate a new immunity by grabbing a new sample of the mutated genetic material."

"It's a remarkably flexible and robust immune system for such simple single-celled organisms."

Dr Fineran says the system reflected the ancient and continuing co-evolutionary arms race between bacteria on one side, and viruses and plasmids on the other.

Viral infections of bacteria also exert a powerful yet invisible effect on the entire planet, says Dr Fineran.

"Their silent but vast and ongoing war underpins everything from how global nutrient cycles -- which rely on bacteria to produce half of Earth's biomass -- operate, to how human pathogens evolve," he says.

"For example, the bacteria that cause cholera and diphtheria have been infected by viruses that provide genes coding for toxins, which converted these bacteria into significant human pathogens."

Plasmids are also key players in moving antibiotic resistance genes between different bacterial species.

"So, discovering more about exactly how bacterial immune systems combat plasmid transfer and acquisition is of considerable interest," he says.


Story Source:

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


Journal Reference:

  1. P. C. Fineran, M. J. H. Gerritzen, M. Suarez-Diez, T. Kunne, J. Boekhorst, S. A. F. T. van Hijum, R. H. J. Staals, S. J. J. Brouns. Degenerate target sites mediate rapid primed CRISPR adaptation. Proceedings of the National Academy of Sciences, 2014; DOI: 10.1073/pnas.1400071111

Cite This Page:

University of Otago. "New light shed on key bacterial immune system." ScienceDaily. ScienceDaily, 7 April 2014. <www.sciencedaily.com/releases/2014/04/140407153917.htm>.
University of Otago. (2014, April 7). New light shed on key bacterial immune system. ScienceDaily. Retrieved October 26, 2014 from www.sciencedaily.com/releases/2014/04/140407153917.htm
University of Otago. "New light shed on key bacterial immune system." ScienceDaily. www.sciencedaily.com/releases/2014/04/140407153917.htm (accessed October 26, 2014).

Share This



More Plants & Animals News

Sunday, October 26, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Deep Sea 'mushroom' Could Be Early Branch on Tree of Life

Deep Sea 'mushroom' Could Be Early Branch on Tree of Life

Reuters - Innovations Video Online (Oct. 24, 2014) Miniature deep sea animals discovered off the Australian coast almost three decades ago are puzzling scientists, who say the organisms have proved impossible to categorise. Academics at the Natural History of Denmark have appealed to the world scientific community for help, saying that further information on Dendrogramma enigmatica and Dendrogramma discoides could answer key evolutionary questions. Jim Drury has more. Video provided by Reuters
Powered by NewsLook.com
Black Bear Cub Goes Sunday Shopping

Black Bear Cub Goes Sunday Shopping

Reuters - Light News Video Online (Oct. 23, 2014) Price check on honey? Bear cub startles Oregon drugstore shoppers. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
Dances With Wolves in China's Wild West

Dances With Wolves in China's Wild West

AFP (Oct. 23, 2014) One man is on a mission to boost the population of wolves in China's violence-wracked far west. The animal - symbol of the Uighur minority there - is under threat with a massive human resettlement program in the region. Duration: 00:41 Video provided by AFP
Powered by NewsLook.com
Breakfast Debate: To Eat Or Not To Eat?

Breakfast Debate: To Eat Or Not To Eat?

Newsy (Oct. 23, 2014) Conflicting studies published in the same week re-ignited the debate over whether we should be eating breakfast. 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:

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