Master E. coli Overview with Picmonic for Medicine

This organism stains gram-negative due to relatively thin peptidoglycan layer in the cell wall.

This organism is rod shaped.

Eosin Methylene Blue is a selective stain used for differentiation of gram-negative bacteria. On EMB, E. coli colonies give a distinctive green sheen to help with identification.

This organism can be differentiated from other gram-negative bacilli because it is lactose-fermenting, causing growth of red pink colonies on MacConkey agar.

This organism can be differentiated from other gram-negative bacilli because it is lactose-fermenting, causing growth of red pink colonies on MacConkey agar.

E. coli is a common cause of food poisoning and can cause diarrhea.

Lipopolysaccharides (LPS) are found in the outer membrane of many gram-negative bacteria and act as endotoxins that can cause a strong immune response. LPS has three components; Lipid A, core, and O antigen. Lipid A is a hydrophobic fatty acid chain that anchors the LPS into the bacterial membrane, and it is responsible for causing septic shock when the bacterial cells are lysed and the fragments are released into the circulation.

Some pathogenic strains contain P pili, an adhesion that binds to a specific galactose disaccharide found on surfaces of uroepithelial cells. Strains with P pili are strongly associated with urinary tract infections with inflammation of the bladder and can also lead to pyelonephritis.

The K antigen refers to a polysaccharide capsule that surrounds some pathogenic strains of E coli. Pathogenic strains of K antigen can cause neonatal meningitis and pneumonia when infants acquire the organism during passage through the birth canal.

The K antigen refers to a polysaccharide capsule that surrounds some pathogenic strains of E coli. Pathogenic strains of K antigen can cause neonatal meningitis and pneumonia when infants acquire the organism during passage through the birth canal.

H antigen refers to flagella, which allows E. coli to be motile.