E. coli is a species of prokaryotic microorganisms within the domain Bacteria, under the phylum Proteobacteria and class Gammaproteobacteria. It is a well-known representative of the bacterial kingdom due to its presence in the intestines of warm-blooded animals, including humans, where it plays a role in digestion and gut health. While many strains of E. coli are harmless or even beneficial, certain pathogenic strains can cause illnesses, such as food poisoning or urinary tract infections.
The classification of E. coli within the bacterial kingdom highlights its single-celled, nucleus-free structure, which distinguishes it from eukaryotic organisms found in other kingdoms like Animals or Plants.