Different E. coli types

Question 1

How are E. coli differentiated?

Answer 1

E. Coli is divided into serotypes based on their H antigen (flagella), K antigen (capsule) and O antigen (lipopolysaccharide endotoxin).

Question 2

Enteropathogenic E. Coli (EPEC)

Answer 2

Adheres to intestinal epithelium using bundle forming pili and destroys microvilli, leading to malabsorption.

Question 3

Enterohemorrhagic E. Coli (EHEC)

Answer 3

contains Shiga-like toxin, which kills enterocytes and can cause hemolytic uremic syndrome (HUS). It is commonly acquired by consuming undercooked beef or contaminated plants. Most strains are non-sorbitol fermenters.

Question 4

Enterotoxigenic E. Coli (ETEC)

Answer 4

uses fimbriae to attach to epithelial cells and secretes cells with heat labile toxin (LT) and heat stable toxin (ST). It is the common cause of traveler’s diarrhea.

Question 5

Enteroinvasive E. Coli (EIEC)

Answer 5

uses a Type III secretion system to invade enterocytes, proliferate, and destroy the epithelium. It causes watery or bloody diarrhea, but milder than EHEC.

Question 6

Enteroaggregative E. Coli (EAEC)

Answer 6

uses aggregative adherence fimbriae (AAF) to make a biofilm of bacterial clusters on the intestinal wall. It causes diarrhea with mucus.

Question 7

Uropathogenic E. Coli (UPEC)

Answer 7

adheres with type I and P pili, contains hemolysin and other toxins, and is the major cause of urinary tract infections (UTIs)