Which of the following is a key characteristic of EHEC infection?

A key characteristic of Enterohemorrhagic Escherichia coli (EHEC) infection is the occurrence of bloody diarrhea. EHEC, particularly the serotype O157:H7, is well-known for causing gastroenteritis that leads to severe symptoms, primarily hemorrhagic colitis. This results in the presence of bloody stools, which is a distinctive feature of this type of infection.

The mechanism behind this symptomatic manifestation involves the production of Shiga toxin by EHEC, which damages the intestinal lining and leads to inflammation and bleeding. Consequently, bloody diarrhea becomes a hallmark symptom used to identify EHEC infections.

While fever, low white blood cell counts, and severe abdominal cramping can occur in EHEC infections, they are not as characteristic as bloody diarrhea. Usually, fever might be present in some cases, but it is not consistently associated with EHEC infection. Similarly, low white blood cell counts are not a primary feature and severe abdominal cramping, although common, is more a symptom of gastrointestinal distress rather than a definitive characteristic of EHEC infection itself.