Virulent New Bacterial Strain Identified As Cause Of European Outbreak
by Scott Hensley

- June 2, 2011

The World Health Organization says the E. coli bacterium behind the outbreak of life-threatening infections in Europe is a new strain, never seen in people before.

At least 18 people have died from infection with the germ, which has struck at least 1,500 people. Almost all of the cases and deaths have occurred in people who either live in Germany or who traveled there recently.

The unique strain isolated from patients is a mutant, Hilda Kruse, a WHO food safety expert, told the Associated Press. It has "various characteristics that make it more virulent and toxin-producing" than the varieties of E. coli that normally live quite peacefully in people's intestines.

BGI, a scientific laboratory in China, has produced a preliminary sequence of the bacterium's genes, which show it's a new type. It's similar to a strain known to cause diarrhea and that was first identified in the Central African Republic.

But the new bacterium has some different genes that appear to account for its virulence and the high rate of hemolytic-uremic syndrome among patients. That syndrome can lead to kidney failure and death. The germ is also armed with genes that would help it defeat common antibiotics.

Germany's Robert Koch Institute says antibiotic resistance isn't a significant problem in the treatment of patients, though, because these sorts of infections shouldn't be treated with antibacterial medicines anyway. Such treatment can actually prolong the excretion of bacteria and the production of toxins.

The World Health Organization says that the source of the outbreak "is still unclear," despite a bunch of ongoing investigations. German officials have warned people not to eat lettuce, tomatoes and cucumbers.

Russia has banned all imports of raw vegetables from the European Union. For its part, WHO hasn't recommended "any trade restrictions related to this outbreak."

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