**Abstract**

*Escherichia coli* is a type of bacteria that lives in many places in the environment, including the gastrointestinal system of humans and warm-blooded animals, where it is part of the gut microbiota. Some strains of *E. coli* can be administered as probiotics and are known to have a positive effect on host health. However, some strains can be pathogenic, causing intestinal and extraintestinal infections in humans as well as animals. *E. coli* is hence a bacterium with a wide range of different natural types of strains, each with its own set of features. Because of its unique qualities, such as simplicity of handling, availability of the entire genome sequence, and capacity to grow in both aerobic and anaerobic conditions, *E. coli* is also a popular bacterium for laboratory research and biotechnology. So, *E. coli* is considered to be the utmost widely utilized microbe in the field of recombinant DNA technology, and it is used in a wide range of industrial and medical applications.

**Keywords:** *Escherichia coli*, Gram-negative bacteria, growth, infection, model organism, pathogenesis
