Are most strains of E-coil harmful?

Most strains of E. coli are harmless and are part of the normal gut flora in humans and animals. However, some strains, particularly Enterohemorrhagic E. coli (EHEC), can cause serious foodborne illnesses, leading to symptoms like severe abdominal cramps and diarrhea. It's important to properly handle and cook food to avoid infections from harmful strains. Overall, while many E. coli strains are benign, caution is warranted with certain pathogenic varieties.