Escherichia coli O-157 is a personified strain of E. coli that appears in Moyashimon, representing the notorious foodborne pathogen. The character is depicted as mischievous and dangerous, reflecting the real bacterium’s association with severe food poisoning and contamination risks. In the series, this character serves as an educational and comedic example of microbiology, helping illustrate the diversity and behavior of microbes through anthropomorphic design. Its role emphasizes both the charm and the cautionary side of the microbial world.