A Microbial Biorealm page on the genus Chroococcus
[[Escherichia coli O157:H7. Image courtesy of OutBreak, Inc. Copyright 2005 - 2007.]]
Class: Gamma Proteobacteria
Species: E. coli
Escherichia coli O157:H7 is an enterohemorrhagic strain of the bacterium Escherichia coli. Escherichia coli O157:H7 is one of the four recognized classes of enterovirulent E. coli which can cause gastroenteritis in human.
Escherichia coli O157:H7 has some Unique characteristics: c Cannot metabolize sorbitol Poor growth at 44-45.5 °C Lacking beta-glucuronidase activity Tolerates low pH well 
E. coli O157:H7 infection often causes severe bloody diarrhea and abdominal cramps; sometimes the infection causes non-bloody diarrhea or no symptoms. Vomiting occurs in about half of persons and fever, usually not high, occurs less than one-third of the time. On the second or third day of illness, stools may become bloody in 30% to 75% of cases. The illness resolves in 5 to 10 days. Infants and the elderly are most susceptible. The incubation period is usually 3-4 days, although rarely the incubation can be as short as 12 hours or as long as 8 days. Most of the time there is no long-term effects. Asymptomatic infection can occur.
Antibiotics are not used with this type of infection. Most people usually recovery within five to 10 days. Sometimes people will develop hemolytic uremic syndrome (HUS),life-threatening disease. Blood transfusions and kidney dialysis can treat HUS.
1. Karch H, Tarr P, Bielaszewska M (2005). Enterohaemorrhagic Escherichia coli in human medicine. Int J Med Microbiol 295 (6-7): 405–18. PMID 16238016.
2. Geoff Copper, Rebecca Young, Claire Campbell,. Guyton Durnin, Linha Phan, Leah McKay. (2006) Escherichia coli O157:H7
3. CALVIN B. JOHNSON (2006).Escherichia coli O157:H7 (E. Coli)