The bacterium E. coli has surfaced again, this time in Japan. Around 8,000 Japanese became ill and several died. This is the same bacterial strain, known as O157:H7, that sickened hundreds of people in the U.S. who ate undercooked Jack-in-the-Box hamburgers. Normally, this bacterium is harmless and occupies the gut of most animals. However, this particular strain seems to have picked up a new gene that produces a toxin. The strain was first identified in 1982 and since then has been showing up in outbreaks all over the world.
Source: "Fierce Bacteria Strain Is a Worldwide Problem" by Philip J. Hilts, New York Times, July 25, 1996.