The gut toxin uses molecules introduced by meat, dairy products, scientists say
WEDNESDAY, Oct. 29 (HealthDay News) -- Researchers say they have found a bacterium that causes food poisoning by targeting a non-human molecule that's absorbed into the body through red meat.
Subtilase cytotoxin, a potent bacterial toxin produced by certain kinds of E. coli bacteria, zeroes in on human cells with a non-human, cellular molecule on their surface. One of its favorite targets appears to be N-glycolylneuraminic acid (Neu5Gc), a type of glycan, or sugar molecule, found in high levels in red meat and dairy products.
Subtilase cytotoxin causes bloody diarrhea and can lead to a potentially fatal disease called haemolytic uraemic syndrome (HUS), which can be contracted by consuming contaminated red meat.
The findings were to be published online Oct. 29 in the journal Nature.
Since humans lack the gene responsible for production of Neu5Gc, it was previously thought that they should be resistant to the toxin. However, the researchers discovered that places where Neu5Gc becomes incorporated into the human body coincide with toxin binding.
"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," research team member Dr. Ajit Varki, a professor of the University of California, San Diego School of Medicine, said in a news release issued by his university. "The Neu5Gc molecule is absorbed into the body, making it a target for the toxin produced by E. coli."
The researchers said that people should eat only well-cook meat or pasteurized dairy products, because both processes destroy contaminating bacteria.
The U.S. National Institute of Diabetes and Digestive and Kidney Diseases has more about bacterial or food-borne illness.
-- Kevin McKeever
SOURCE: University of California - San Diego, news release, Oct. 29, 2008
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