Final answer:
Escherichia coli O157:H7, a dangerous strain of E. coli, can cause hemolytic uremic syndrome (HUS) in children. It belongs to the group of enterohemorrhagic E. coli (EHEC) and produces a Shiga-like toxin that causes severe illness. Prevention involves ensuring food safety with properly processed foods.
Step-by-step explanation:
Escherichia coli O157:H7 is a strain of the bacterium E. coli that is responsible for causing hemolytic uremic syndrome (HUS) among children. This particular strain belongs to a category known as enterohemorrhagic E. coli (EHEC), which can lead to severe, life-threatening symptoms such as bloody diarrhea with severe cramping, and in severe cases, it leads to HUS, a condition characterized by the destruction of red blood cells and acute kidney failure. The strain is known for not fermenting sorbitol, which helps in its diagnosis through culture, often using sorbitol-MacConkey agar, differentiating it from less pathogenic E. coli strains. It is also characterized by the presence of surface antigens, Shiga-like toxin production, which can have devastating effects on the host's endothelial cells, particularly in the intestines and kidneys.
Contamination with E. coli O157:H7 typically originates from improperly processed foods such as undercooked meats and raw vegetables. Outbreaks of this strain have led to recalls of food products to prevent further spread of infection. The pathogenic effects of this bacterium are a result of the production of Shiga toxin, acquired through horizontal gene transfer, which leads to cellular death and severe conditions like hemorrhagic colitis and HUS in the most severe cases. These effects can result in the need for intensive medical intervention, and long-term health issues, particularly related to kidney function.