Is E. coli zoonotic?

Is E. coli zoonotic?

• A. No
• B. Only in cattle
• C. Only in pigs
• D. Yes (O157:H7, STEC especially)

Answer: (D)

Zoonotic potential in E. coli comes from specific pathogenic strains, not from the species as a whole. The standout example is Shiga toxin–producing E. coli, especially the O157:H7 serotype. These strains live in animals, with cattle being a major reservoir, and can reach humans through undercooked ground beef, unpasteurized dairy, contaminated produce or water, or direct contact with animals. While most E. coli are harmless gut residents or commensals, the STEC group can cross from animals to people and cause severe illness, including hemorrhagic diarrhea and, in some cases, kidney injury. So, E. coli can be zoonotic, particularly for O157:H7 and related STEC strains.

Zoonotic potential in E. coli comes from specific pathogenic strains, not from the species as a whole. The standout example is Shiga toxin–producing E. coli, especially the O157:H7 serotype. These strains live in animals, with cattle being a major reservoir, and can reach humans through undercooked ground beef, unpasteurized dairy, contaminated produce or water, or direct contact with animals. While most E. coli are harmless gut residents or commensals, the STEC group can cross from animals to people and cause severe illness, including hemorrhagic diarrhea and, in some cases, kidney injury. So, E. coli can be zoonotic, particularly for O157:H7 and related STEC strains.