Featured Research

from universities, journals, and other organizations

New Technique Puts DNA Profiling Of E. Coli On Fast Track

Date:
March 14, 2008
Source:
Michigan State University
Summary:
Using new genetic techniques, scientists are unlocking the secrets of how E. coli bacteria contaminate food and make people sick. Michigan State University has developed a new technique to test the DNA of E. coli bacteria by examining very small genetic changes called single nucleotide polymorphisms or SNPs. Using SNPs, scientists analyzed 96 markers, making genetic analysis of pathogenic bacteria possible at a rate never before accomplished.

Using new genetic techniques, scientists are unlocking the secrets of how E coli bacteria contaminate food and make people sick.

Michigan State University has developed a new technique to test the DNA of E. coli bacteria by examining very small genetic changes called single nucleotide polymorphisms or SNPs (pronounced snips). Using SNPs, scientists analyzed 96 markers, making genetic analysis of pathogenic bacteria possible at a rate never before accomplished.

"It used to take three months to score one gene individually," said Thomas Whittam, Hannah Distinguished Professor at the National Food Safety and Toxicology Center at MSU. "Now, we are working on a new, more rapid system that can do thousands of genes per day."

In a new study* Whittam and his co-authors looked at the DNA of more than 500 strains of a particularly dangerous member of the E. coli family, O157:H7. In collaboration with David Alland of the University of Medicine and Dentistry of New Jersey, Whittam discovered that individual bacteria could be separated into nine major groups, called clades.

E coli makes people sick because they produce toxins, called Shiga toxins. These toxins block protein synthesis, an essential cellular function, particularly in the kidneys. What Whittam found was that the different clades produced different kinds of Shiga toxins in varying amounts based on their DNA.

"For the first time, we know why some outbreaks cause serious infections and diseases and others don't," Whittam said. "The different E. coli groups produce different toxins."

Rapid genetic characterization also opens up a new world of possibilities for identifying the bacterial culprits in outbreaks and finding out where they originated.

E. coli usually come from animal waste contaminating human sources of food or water. Finding out how the bacteria entered the food source always has been a challenge, but now food safety experts can use DNA just like police use DNA at crime scenes. Scientists will be able to identify those bacteria making people sick, find out where they entered the food source and then use this information to reduce contamination.

"This is the first time anyone has been able to classify very closely related groups," Whittam said. "This is also the first time we can tell the differences in how they cause disease."

Whittam also has plans to use this methodology to study other bacterial strains, like Shigella, a major cause of diarrhea around the world. "This new equipment can be used to identify hundreds of thousands of pathogenic bacteria," Whittam said.

*The article "Variation in Virulence Among Clades of Escherichia coli O157:H7 Associated With Disease Outbreaks," is published March 10 in the Proceedings of the National Academy of Sciences.

The National Institute of Allergy and Infectious Diseases of National Institutes of Health through Food and Waterborne Diseases Integrated Research Network supported this research.


Story Source:

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


Cite This Page:

Michigan State University. "New Technique Puts DNA Profiling Of E. Coli On Fast Track." ScienceDaily. ScienceDaily, 14 March 2008. <www.sciencedaily.com/releases/2008/03/080310181602.htm>.
Michigan State University. (2008, March 14). New Technique Puts DNA Profiling Of E. Coli On Fast Track. ScienceDaily. Retrieved April 19, 2014 from www.sciencedaily.com/releases/2008/03/080310181602.htm
Michigan State University. "New Technique Puts DNA Profiling Of E. Coli On Fast Track." ScienceDaily. www.sciencedaily.com/releases/2008/03/080310181602.htm (accessed April 19, 2014).

Share This



More Plants & Animals News

Saturday, April 19, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Vermont Goat Meat Gives Refugees Taste of Home

Vermont Goat Meat Gives Refugees Taste of Home

AP (Apr. 18, 2014) Dairy farmers and ethnic groups in Vermont are both benefiting from a unique collaborative effort that's feeding a growing need for fresh and affordable goat meat. (April 18) Video provided by AP
Powered by NewsLook.com
First Ever 'Female Penis' Discovered In Animal Kingdom

First Ever 'Female Penis' Discovered In Animal Kingdom

Newsy (Apr. 18, 2014) Not only are these newly discovered bugs' sex organs reversed, but they also mate for up to 70 hours. Video provided by Newsy
Powered by NewsLook.com
Little Progress Made In Fighting Food Poisoning, CDC Says

Little Progress Made In Fighting Food Poisoning, CDC Says

Newsy (Apr. 18, 2014) A new report shows rates of two foodborne infections increased in the U.S. in recent years, while salmonella actually dropped 9 percent. Video provided by Newsy
Powered by NewsLook.com
The Great British Farmland Boom

The Great British Farmland Boom

Reuters - Business Video Online (Apr. 17, 2014) Britain's troubled Co-operative Group is preparing to cash in on nearly 18,000 acres of farmland in one of the biggest UK land sales in decades. As Ivor Bennett reports, the market timing couldn't be better, with farmland prices soaring over 270 percent in the last 10 years. 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:
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