Escherichia coli

Definition

Escherichia coli (E. coli) is a Gram-negative, rod-shaped bacterium commonly found in the intestines of warm-blooded organisms. While most strains are harmless, some can cause serious food poisoning and infections.

5 Must Know Facts For Your Next Test

1. E. coli belongs to the family Enterobacteriaceae and is a member of the Proteobacteria phylum.
2. Certain pathogenic strains of E. coli, such as O157:H7, produce Shiga toxin, leading to severe gastrointestinal illness.
3. E. coli is often used as an indicator organism for fecal contamination in water quality testing.
4. It plays a crucial role in microbial genetics and biotechnology, including cloning and gene expression studies.
5. Antibiotic resistance in E. coli is a growing concern, particularly in urinary tract infections.

Review Questions

• What are the primary characteristics that classify E. coli as a Gram-negative bacterium?
• Which strain of E. coli is known for producing Shiga toxin and causing severe gastrointestinal illness?
• How is E. coli used in modern applications of microbial genetics?

Related terms

Shiga Toxin: A potent toxin produced by certain strains of Escherichia coli that can cause severe illness.

Gram-Negative Bacteria: Bacteria characterized by a thin peptidoglycan layer and an outer membrane containing lipopolysaccharides.

Enterobacteriaceae:

A large family of Gram-negative bacteria that includes many pathogens such as Escherichia, Salmonella, and Yersinia.