Featured Research

from universities, journals, and other organizations

Eating Red Meat Sets Up Target For Disease-causing Bacteria, Study Finds

Date:
October 30, 2008
Source:
University of California - San Diego
Summary:
Offering another reason why eating red meat could be bad for you, researchers have uncovered the first example of a bacterium that causes food poisoning in humans when it targets a non-human molecule absorbed into the body through red meats such as lamb, pork and beef.

Offering another reason why eating red meat could be bad for you, scientists have uncovered the first example of a bacterium that causes food poisoning in humans when it targets a non-human molecule absorbed into the body through red meats such as lamb, pork and beef.
Credit: iStockphoto/Robert Simon

Offering another reason why eating red meat could be bad for you, an international research team, including University of California, San Diego School of Medicine professor Ajit Varki, M.D., has uncovered the first example of a bacterium that causes food poisoning in humans when it targets a non-human molecule absorbed into the body through red meats such as lamb, pork and beef.

In findings to be published on line October 29th in advance of print in the journal Nature, the scientists discovered that a potent bacterial toxin called subtilase cytotoxin specifically targets human cells that have a non-human, cellular molecule on their surface. The molecule –N-glycolylneuraminic acid (Neu5Gc) – is a type of glycan, or sugar molecule, that humans don't naturally produce.

Subtilase cytotoxin is produced by certain kinds of E. coli bacteria, causing bloody diarrhea and a potentially fatal disease called haemolytic uraemic syndrome (HUS) in humans. Humans usually become infected after eating contaminated red meat, which is why this is also known as "hamburger" disease.

Varki, UC San Diego School of Medicine distinguished professor of medicine and cellular and molecular medicine, and co-director of the UCSD Glycobiology Research and Training Center, previously discovered that humans don't produce Neu5Gc because they lack the gene responsible for its production. Therefore, it was thought that humans should be resistant to the toxin.

"Ironically, humans may set themselves up for an increased risk of illness from this kind of E. coli bacteria present in contaminated red meat or dairy, because these very same products have high-levels of Neu5Gc," Varki explained. "The Neu5Gc molecule is absorbed into the body, making it a target for the toxin produced by E. coli."

In the Nature study, the researchers discovered that sites where the Neu5Gc has been incorporated into the human body coincide with toxin binding. "When the toxin binds to the non-human Neu5Gc receptors, it can result in serious food-poisoning and other symptoms in humans," said Varki. The research emphasizes the need for people to eat only well-cook meat or pasteurized dairy products, processes that destroy contaminating bacteria.

Five years ago, Varki and his colleagues at the UC San Diego School of Medicine published a paper in the Proceedings of the National Academy of Sciences describing how Neu5Gc is absorbed into human tissues – including the surface of cells lining the intestines and blood vessels – as a result of eating red meat and milk products. At the time, the researchers also showed that this foreign molecule generates an immune response that could potentially lead to inflammation in human tissues. The UC San Diego study was the first to investigate human dietary absorption of the Neu5Gc glycans which, while not produced in humans, does occur naturally in red meats. Levels are very low or undetectable in fruits, vegetables, eggs, poultry and fish. The researchers proved that people who ingest Neu5Gc incorporate some of it into their tissues, and demonstrated that many generated an immune response against the molecule, conjecturing that a lifetime of gradual incorporation of this glycan "invader" could result in disease.

The UC San Diego team included postdoctoral fellow Jonas C. Lφfling and professor of pathology Nissi M. Varki. The international research collaborators included Jamie Rossjohn and Dr. Travis Beddoe, as well as Emma Byres and Matthew C.C. Wilce from Monash University in Victoria, Australia; Adrienne W. Paton, James C. Paton, Ursula M. Talbot and Damien C. Chong of the University of Adelaide, South Australia; David F. Smith, Emory University School of Medicine, Atlanta, Georgia; and Hai Yu, Shengshu Huang and Xi Chen, UC Davis Department of Chemistry.

The research was funded by the National Institutes of Health, and by Australia's National Health and Medical Research Council.


Story Source:

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


Cite This Page:

University of California - San Diego. "Eating Red Meat Sets Up Target For Disease-causing Bacteria, Study Finds." ScienceDaily. ScienceDaily, 30 October 2008. <www.sciencedaily.com/releases/2008/10/081029141035.htm>.
University of California - San Diego. (2008, October 30). Eating Red Meat Sets Up Target For Disease-causing Bacteria, Study Finds. ScienceDaily. Retrieved July 30, 2014 from www.sciencedaily.com/releases/2008/10/081029141035.htm
University of California - San Diego. "Eating Red Meat Sets Up Target For Disease-causing Bacteria, Study Finds." ScienceDaily. www.sciencedaily.com/releases/2008/10/081029141035.htm (accessed July 30, 2014).

Share This




More Plants & Animals News

Wednesday, July 30, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: Thousands Flocking to German Crop Circle

Raw: Thousands Flocking to German Crop Circle

AP (July 30, 2014) — Thousands of people are trekking to a Bavarian farmer's field to check out a mysterious set of crop circles. (July 30) Video provided by AP
Powered by NewsLook.com
Concern Grows Over Worsening Ebola Crisis

Concern Grows Over Worsening Ebola Crisis

AFP (July 30, 2014) — Pan-African airline ASKY has suspended all flights to and from the capitals of Liberia and Sierra Leone amid the worsening Ebola health crisis, which has so far caused 672 deaths in Guinea, Liberia and Sierra Leone. Duration: 00:43 Video provided by AFP
Powered by NewsLook.com
At Least 20 Chikungunya Cases in New Jersey

At Least 20 Chikungunya Cases in New Jersey

AP (July 30, 2014) — At least 20 New Jersey residents have tested positive for chikungunya, a mosquito-borne virus that has spread through the Caribbean. (July 30) Video provided by AP
Powered by NewsLook.com
Raw: Otters Enjoy Water Slides at Japan Zoo

Raw: Otters Enjoy Water Slides at Japan Zoo

AP (July 30, 2014) — River otters were hitting the water slides to beat the summer heatwave on Wednesday at Ichikawa City's Zoological and Botanical Garden. (July 30) 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