Nature
[Escherichia coli] is one of the most familiar and common bacteria. Millions live relatively benignly in the human lower gut and their remains form a significant volume of faecal matter. However, the bacterium is readily transmitted under unhygienic conditions and can be the cause of cross-infections between individuals and can cause illness under certain conditions, for example urinary infections in the bladder.
Background
Researchers have mapped the full genetic sequence of one strain of [E. coli] 0157:H7, which has caused a steadily growing number of infections worldwide since 1982. Compared with the genome of the ordinary, benign strain of E. coli, the disease-causing strain contains nearly 1,400 additional genes. It is thought that some of these genes create the toxins that make people ill, causing severe cramping and diarrhoea and, in the young and elderly, potentially deadly complications.