Featured Research

from universities, journals, and other organizations

How salmonella avoids the body's immune response

Date:
March 14, 2012
Source:
University of California - Irvine
Summary:
Researchers have discovered how salmonella, a bacterium found in contaminated raw foods that causes major gastrointestinal distress in humans, thrives in the digestive tract despite the immune system's best efforts to destroy it.

UC Irvine researchers have discovered how salmonella, a bacterium found in contaminated raw foods that causes major gastrointestinal distress in humans, thrives in the digestive tract despite the immune system's best efforts to destroy it.

Their findings help explain why salmonella is difficult to eradicate and point to new approaches for possible treatments. Most people infected with salmonella suffer from diarrhea, fever and abdominal cramps for up to seven days before the infection resolves.

Lead researcher Manuela Raffatellu, a UCI assistant professor of microbiology & molecular genetics, and colleagues identified a novel molecular mechanism that allows salmonella to survive. Results of their study appear in the March issue of Cell Host & Microbe.

Pathogens like salmonella flourish and cause disease in humans through a process by which they acquire metal ions, such as zinc, from the body. One of the body's key immune responses is to flood the infected area with antimicrobial proteins that include calprotectin, which removes zinc. Without enough of this vital element, most pathogens eventually die.

Raffatellu's team found, however, that salmonellae overcome this immune response by expressing specialized transporter proteins that enable the bacteria to acquire zinc in spite of calprotectin reducing the amount available in the digestive tract. This distinctive mechanism lets salmonellae continue proliferating.

At the same time, calprotectin inadvertently promotes salmonella growth by killing the microbes that normally reside within the intestines and help the immune system battle pathogenic bacteria.

"We're beginning to learn more about the mechanisms that allow pathogens like salmonella to evade our natural defenses and make us sick," Raffatellu said. "In light of this, if we can devise therapies that block the acquisition of zinc and other metals by salmonella specifically, we can fight this infection."

Additionally, she said, the new findings may have relevance for other illnesses, such as inflammatory bowel disease and colon cancer, in which high levels of calprotectin are detected.

Also contributing to the study, which was supported by grants from the National Institutes of Health, were Janet Z. Liu, Stefan Jellbauer, Adam Poe, Vivian Ton, Michele Pesciaroli, Martin Hosking, Robert A. Edwards and Thomas E. Lane of UCI; Thomas Kehl-Fie, Nicole A. Restrepo, Walter J. Chazin and Eric P. Skaar of Vanderbilt University; Andrea Battistoni of the University of Rome; Thomas Vogl and Johannes Roth of the University of Munster, Germany; and Paolo Pasquali of the Superior Health Institute in Rome.


Story Source:

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


Journal Reference:

  1. Janet Z. Liu, Stefan Jellbauer, Adam J. Poe, Vivian Ton, Michele Pesciaroli, Thomas E. Kehl-Fie, Nicole A. Restrepo, Martin P. Hosking, Robert A. Edwards, Andrea Battistoni et al. Zinc Sequestration by the Neutrophil Protein Calprotectin Enhances Salmonella Growth in the Inflamed Gut. Cell Host & Microbe, 15 March 2012 DOI: 10.1016/j.chom.2012.01.017

Cite This Page:

University of California - Irvine. "How salmonella avoids the body's immune response." ScienceDaily. ScienceDaily, 14 March 2012. <www.sciencedaily.com/releases/2012/03/120314125923.htm>.
University of California - Irvine. (2012, March 14). How salmonella avoids the body's immune response. ScienceDaily. Retrieved September 20, 2014 from www.sciencedaily.com/releases/2012/03/120314125923.htm
University of California - Irvine. "How salmonella avoids the body's immune response." ScienceDaily. www.sciencedaily.com/releases/2012/03/120314125923.htm (accessed September 20, 2014).

Share This



More Health & Medicine News

Saturday, September 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

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
Jury Delivers Verdict in Salmonella Trial

Jury Delivers Verdict in Salmonella Trial

AP (Sep. 19, 2014) A federal jury has convicted three people in connection with an outbreak of salmonella poisoning five years ago that sickened hundreds of people and was linked to a number of deaths. (Sept. 19) 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