Escherichia coli Escherichia coli O157:H7 infections

Escherichia coli appearance

  • Gram-negative rods with rounded ends
  • motile (peritrichous flagella)
  • non-spore-forming

Infections caused by Escherichia coli O157:H7

Escherichia coli O157:H7 is an enterohemorrhagic serotype of the bacterium Escherichia coli and a cause of illness, typically through consumption of contaminated food. Infection may lead to hemorrhagic diarrhea, and to kidney failure. Transmission is via the fecal-oral route, and most illness has been through distribution of contaminated raw leaf green vegetables and undercooked meat.

E. coli O157:H7 infection often causes severe, acute hemorrhagic diarrhea (although nonhemorrhagic diarrhea is also possible) and abdominal cramps. Usually little or no fever is present, and the illness resolves in five to 10 days. It can also be asymptomatic. In some people, particularly children under five years of age and the elderly, the infection can cause hemolytic uremic syndrome (HUS), in which the red blood cells are destroyed and the kidneys fail. About 2–7% of infections lead to this complication. In the United States, HUS is the principal cause of acute kidney failure in children, and most cases of HUS are caused by E. coli O157:H7 (Wikipedia).

Escherichia coli O157:H7 treatment

Fluid replacement and blood pressure support may be necessary to prevent death from dehydration. Most victims recover without antibiotic treatment in five to 10 days. There is no evidence that antibiotics improve the course of disease, and treatment with antibiotics may precipitate hemolytic uremic syndrome (Wikipedia).



Colony appearance

Escherichia coli morphology Escherichia coli cell morphology Escherichia coli Gram-stain