E. coli belongs to a group of bacteria that cause diarrhea and sepsis in infants and young animals. E. coli has the following characteristics: 1. It belongs to a prokaryotic organism. 2. E. coli is a mutually beneficial symbiotic condition when it does not cause human illness. And E. coli can be considered as a parasite when it causes human body to be sick. 3. E. coli can be applied to fermentation. E. coli can cause the following diseases in the human body: 1. It causes sepsis in infants and the elderly. 2. It can cause urinary diseases such as urethritis and cystitis. It can be prevented by the following ways: 1, after throwing garbage and touching dirty places, you should wash your hands with disinfectant. 2, tap water for drinking should be boiled before drinking. 3, food should be cleaned before eating.