Featured Research

from universities, journals, and other organizations

Method developed to detect stealthy, 'hypervirulent' Salmonella strains

Date:
April 12, 2012
Source:
University of California - Santa Barbara
Summary:
A recent discovery of "hypervirulent" Salmonella bacteria has given researchers a means to potentially prevent food poisoning outbreaks from these particularly powerful strains.

Salmonella typhimurium (red) invades cultured human cells in this color-enhanced scanning electron micrograph.
Credit: Rocky Mountain Laboratories, NIAID, NIH

A recent discovery of "hypervirulent" Salmonella bacteria has given UC Santa Barbara researchers Michael Mahan and Douglas Heithoff a means to potentially prevent food poisoning outbreaks from these particularly powerful strains.

Their findings have been published in the journal PLoS Pathogens.

Salmonella is the most common cause of infection, hospitalization, and death due to foodborne illness in the U.S. This burden may continue to worsen due to the emergence of new strains that would tax current health-control efforts. To address this problem, researchers sought out -- and found -- hypervirulent strains that present a potential risk to food safety and the livestock industry.

An international team of scientists -- which also included Robert Sinsheimer and William Shimp from UCSB; Yi Xie and Bart Weimer from UC Davis; and John House from University of Sydney, Australia -- conducted a global search for hypervirulent Salmonella strains. They were found among isolates derived from livestock, and rendered current vaccines obsolete.

Bacteria behave like a Trojan Horse, exposing their weapons only after initiating infection. "These strains exhibit this behavior in the extreme -- essentially having a '5th gear' they can switch to during infection," said Heithoff, lead author of the paper.

Previous efforts to find hypervirulent strains were unsuccessful since bacteria behave much like their less-virulent cousins after environmental exposure. "The trick was to assess their virulence during infection -- before they switch back to a less-virulent state in the lab," said Professor Mahan.

Now that researchers know what to look for, they are developing methods to rapidly detect and discriminate the more harmful strains from their less-virulent cousins. The strategy is aided by a special medium utilized by the researchers that forces the bacteria to reveal their weapons in the laboratory -- the first step in the design of therapeutics to combat them.

Humans usually get Salmonella food poisoning from eating contaminated beef, chicken, or eggs. However, animal waste can contaminate fields where fruits, nuts, and vegetables are grown, thus posing a particular health concern for vegetarians. The threat is exacerbated when these foods are not cooked. Salmonella control efforts are expensive -- recent estimates place this cost up to $14.6 billion annually in the U.S.

As hypervirulent strains pose a potential risk to human and animal health, mitigation efforts warrant researchers' careful attention. "Now that we have identified the problem -- and potential solutions -- we just need to get to work," Heithoff said.

This research was launched with support from The G. Harold & Leila Y. Mathers Foundation, which then leveraged additional funding from the U.S. Department of Agriculture, National Institutes of Health, U.S. Army, and Santa Barbara Cottage Hospital Research Program.


Story Source:

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


Journal Reference:

  1. Douglas M. Heithoff, William R. Shimp, John K. House, Yi Xie, Bart C. Weimer, Robert L. Sinsheimer, Michael J. Mahan. Intraspecies Variation in the Emergence of Hyperinfectious Bacterial Strains in Nature. PLoS Pathogens, 2012; 8 (4): e1002647 DOI: 10.1371/journal.ppat.1002647

Cite This Page:

University of California - Santa Barbara. "Method developed to detect stealthy, 'hypervirulent' Salmonella strains." ScienceDaily. ScienceDaily, 12 April 2012. <www.sciencedaily.com/releases/2012/04/120412182340.htm>.
University of California - Santa Barbara. (2012, April 12). Method developed to detect stealthy, 'hypervirulent' Salmonella strains. ScienceDaily. Retrieved September 21, 2014 from www.sciencedaily.com/releases/2012/04/120412182340.htm
University of California - Santa Barbara. "Method developed to detect stealthy, 'hypervirulent' Salmonella strains." ScienceDaily. www.sciencedaily.com/releases/2012/04/120412182340.htm (accessed September 21, 2014).

Share This



More Health & Medicine News

Sunday, September 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Sierra Leone in Lockdown to Control Ebola

Sierra Leone in Lockdown to Control Ebola

AP (Sep. 21, 2014) Sierra Leone residents remained in lockdown on Saturday as part of a massive effort to confine millions of people to their homes in a bid to stem the biggest Ebola outbreak in history. (Sept. 20) Video provided by AP
Powered by NewsLook.com
Sierra Leone's Nationwide Ebola Curfew Underway

Sierra Leone's Nationwide Ebola Curfew Underway

Newsy (Sep. 20, 2014) Sierra Leone is locked down as aid workers and volunteers look for new cases of Ebola. Video provided by Newsy
Powered by NewsLook.com
Changes Found In Brain After One Dose Of Antidepressants

Changes Found In Brain After One Dose Of Antidepressants

Newsy (Sep. 19, 2014) A study suggest antidepressants can kick in much sooner than previously thought. Video provided by Newsy
Powered by NewsLook.com
Could Grief Affect The Immune Systems Of Senior Citizens?

Could Grief Affect The Immune Systems Of Senior Citizens?

Newsy (Sep. 19, 2014) The study found elderly people are much more likely to become susceptible to infection than younger adults going though a similar situation. 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