How does EIEC differ from other diarrheagenic E. coli in terms of pathology and stool?

How does EIEC differ from other diarrheagenic E. coli in terms of pathology and stool?

• A. EIEC invades colonic mucosa producing inflammatory dysentery with blood and pus; stool mimics shigellosis.
• B. EIEC produces Shiga toxin causing HUS.
• C. EIEC causes persistent watery diarrhea via fimbriae.
• D. EIEC is nonpathogenic.

Answer: (A)

EIEC differentiates itself by invading the colonic mucosa, which triggers a strong inflammatory response with neutrophils and mucosal damage. This invasion produces an inflammatory dysentery picture, so the stool often contains blood and pus and resembles shigellosis. The key point is that the illness is driven by invasion of the gut lining rather than toxin-mediated effects. Unlike toxin-producing DEC, EIEC does not generate Shiga toxin, so complications like HUS are not typical. Other DEC types tend to cause watery diarrhea (ETEC), hemorrhagic or persistent diarrhea via toxins (EHEC/STEC and others), or noninvasive patterns, rather than the Shigella-like inflammatory dysentery seen with EIEC.

EIEC differentiates itself by invading the colonic mucosa, which triggers a strong inflammatory response with neutrophils and mucosal damage. This invasion produces an inflammatory dysentery picture, so the stool often contains blood and pus and resembles shigellosis. The key point is that the illness is driven by invasion of the gut lining rather than toxin-mediated effects. Unlike toxin-producing DEC, EIEC does not generate Shiga toxin, so complications like HUS are not typical. Other DEC types tend to cause watery diarrhea (ETEC), hemorrhagic or persistent diarrhea via toxins (EHEC/STEC and others), or noninvasive patterns, rather than the Shigella-like inflammatory dysentery seen with EIEC.