London: A mix of two dangerous E coli strains caused the recent deadly food poisoning outbreak in Germany, according to a new study of the bacteria's DNA.
Scientists said the E coli outbreak strain combined one that makes a toxin and another that sticks to the gut in a way that potentially speeds up the body's absorption of the toxin. They described it as "unprecedented" in its lethality.
"The two strains are in themselves quite nasty," said Hugh Pennington, an emeritus professor of microbiology at the University of Aberdeen, who wrote an accompanying commentary on the research.
"It may be that more of the bugs are sticking to the intestines, and that may result in more toxin being produced," he said.
Experts had earlier suggested, based on an early DNA sequence of the bacteria, that the new strain was particularly aggressive because it reproduced quickly and released more toxin than similar bacteria.
Unlike previous E coli outbreaks, the German strain caused three times as many cases of a severe complication that can lead to kidney failureIt was the deadliest E coli outbreak in history, infecting 3,601 people and killing 39 across Europe, with most cases in Germany. More than 800 people developed kidney problems from the outbreak that peaked in late May.