WEDNESDAY, June 22 (HealthDay News) -- The strain of E. coli bacteria that this month killed dozens of people in Europe and sickened thousands more may be more deadly because of the way it has evolved, a new study suggests.
Scientists say this strain of E. coli produces a particularly noxious toxin and also has a tenacious ability to hold on to cells within the intestine. This, alongside the fact that it is also resistant to many antibiotics, has made the so-called O104:H4 strain both deadlier and easier to transmit, German researchers report.
"This strain of E. coli is much nastier than its [more common] cousin E. coli O157, which is nasty enough -- about three times more virulent," said Hugh Pennington, emeritus professor of bacteriology at the University of Aberdeen in Scotland and author of an accompanying editorial published online June 23 in The Lancet Infectious Diseases.
Another study, published the same day in the New England Journal of Medicine, concludes that, as of June 18, more than 3,200 people have fallen ill in Germany due to the outbreak, including 39 deaths.
In fact, the German strain -- traced to sprouts raised at a German organic farm -- "was responsible for the deadliest E. coli outbreak in history," Pennington said. "It may well be so nasty because it combines the virulence factors of shiga toxin, produced by E. coli O157, and the mechanism for sticking to intestinal cells used by another strain of E. coli, enteroaggregative E. coli, which is known to be an important cause of diarrhea in poorer countries," he said.
Shiga toxin can also help spur what doctors call "hemolytic uremic syndrome," a potentially fatal form of kidney failure. In the New England Journal of Medicine study, German researchers say that 25 percent of outbreak cases involved this complication.
The bottom line, according to Pennington: "E. coli
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