Featured Research

from universities, journals, and other organizations

Salmonella Strain's Path To Virulence Uncovered

Date:
April 24, 2009
Source:
USDA/Agricultural Research Service
Summary:
Scientists have uncovered genetic evidence about the evolutionary path that transformed Salmonella enteritidis from an innocuous bacterium into a virulent pathogen.

ARS scientist Jean Guard-Bouldin is developing a better understanding of just how Salmonella enteritidis evolved the ability to infect eggs, knowledge that may someday help reduce infections.
Credit: Photo by Stephen Ausmus

Agricultural Research Service (ARS) scientists have uncovered genetic evidence about the evolutionary path that transformed Salmonella enteritidis from an innocuous bacterium into a virulent pathogen.

S. enteritidis, like many bacteria, reproduces very quickly--every 20 minutes in optimal conditions, according to veterinary medical officer Jean Guard-Bouldin in the ARS Egg Safety and Quality Research Unit in Athens, Ga.

Such a fast reproductive pace allows the organism to accumulate genetic variations. Only healthy competitors go on to reproduce, survive and develop the mechanisms needed to infect the egg. Using DNA analysis, Guard-Bouldin is looking at evolutionary evidence to determine how some S. enteritidis strains became pathogenic. Studying how S. enteritidis evolves and infects hens on the farm may someday help reduce levels of infection.

Guard-Bouldin and her colleagues found S. enteritidis strains to be so similar genetically that they appear identical, yet they may behave differently inside the hen. To distinguish between the apparently identical genomes, researchers must use a technique called "whole-genome mutational mapping" to analyze multiple strains.

Through these analyses, the researchers developed a timeline of when S. enteritidis first became capable of getting inside the egg from hen reproductive organs--approximately 36 years ago. It appears that a large-scale swap of DNA between strains, in association with the emergence of egg contamination, created a hybrid strain of S. enteritidis.

This hybrid strain had the ability to contaminate the internal contents of eggs. Later, it also split very quickly into two lineages, each carrying one virus. Both of the newly split lineages continued to evolve and eventually began to vary in their ability to contaminate eggs and to survive on the farm.


Story Source:

The above story is based on materials provided by USDA/Agricultural Research Service. Note: Materials may be edited for content and length.


Cite This Page:

USDA/Agricultural Research Service. "Salmonella Strain's Path To Virulence Uncovered." ScienceDaily. ScienceDaily, 24 April 2009. <www.sciencedaily.com/releases/2009/04/090419202242.htm>.
USDA/Agricultural Research Service. (2009, April 24). Salmonella Strain's Path To Virulence Uncovered. ScienceDaily. Retrieved August 27, 2014 from www.sciencedaily.com/releases/2009/04/090419202242.htm
USDA/Agricultural Research Service. "Salmonella Strain's Path To Virulence Uncovered." ScienceDaily. www.sciencedaily.com/releases/2009/04/090419202242.htm (accessed August 27, 2014).

Share This




More Plants & Animals News

Wednesday, August 27, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Super Healthful Fruits and Vegetables: Which Are Best?

Super Healthful Fruits and Vegetables: Which Are Best?

Ivanhoe (Aug. 27, 2014) We all know that it is important to eat our fruits and vegetables but do you know which ones are the best for you? Video provided by Ivanhoe
Powered by NewsLook.com
Raw: Firefighters Rescue Puppy Stuck in Tire

Raw: Firefighters Rescue Puppy Stuck in Tire

AP (Aug. 26, 2014) It took Houston firefighters more than an hour to free a puppy who got its head stuck in a tire. (Aug. 26) Video provided by AP
Powered by NewsLook.com
Have You Ever Been 'Sleep Drunk?' 1 in 7 Has

Have You Ever Been 'Sleep Drunk?' 1 in 7 Has

Newsy (Aug. 26, 2014) A study published in the journal "Neurology" interviewed more than 19,000 people and found 15 percent suffer from being "sleep drunk." Video provided by Newsy
Powered by NewsLook.com
Activists Urge NYC Mayor to Ban Carriage Horses

Activists Urge NYC Mayor to Ban Carriage Horses

AP (Aug. 26, 2014) A group of New Yorkers are putting Mayor Bill de Blasio on notice for what they say is reneging on his campaign promise to ban carriage horses. They rallied Tuesday near the mayor's Gracie Mansion home. (Aug. 26) 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