Escherichia Coli (E. Coli)

Last updated 10.12.13

Features

- G- rod

- Enterobactericeae family

- Facultive anaerobe

- +/- flagella

- Faecal coliform

- G-, rod shaped, non-sporulating facultive anerobe which produce acid gas from lactose

- Commensal flora

- Produces vitamin K

- Prevents growth of pathogenic bacteria

- Colonises infants GIT by 40hrs post birth

- Faecol-oral transmission

- O157:H7 also transmitted by flies or direct animal contact

- Produce heat stable/liable enterotoxins

Classification

- Serotypes: >700

- O, H & K antigens

- O157:H7 = HUS, gastroenteritis

- O121, O104:H21 = gastroenteritis

- Nissle 1917 (Mutaflor) = probiotic

- Verotypes

- Enterotoxigenic (ETEC)

- Diarrhoea

- Leading cause of bacterial diarrhoea in developing world & of travelers diarrhoea

- Enteropathogenic (EPEC)

- Diarrhoea (+/- invasive)

- Enteroinvasinve (EIEC)

- Diarrhoea + high fever

- Resembles Shigellosis

- Enterohaemorrhagic (EHEC)

- HUS: O157:H7 causes bloody diarrhoea wo fever

- Enteroaggregative (EAEC)

- Watery diarrhoea wo fever

- Uropathogenic (UPEC):

- UTI

- Fimbria bind to endothelial cells

Presentations

- UTI

- Cause of 90%

- Chronic UTI if biofilm forming (K antigen)

- Gastroenteritis

- Neonatal Meningitis

- Haemolytic Uraemic Syndrome (HUS)

- Pneumonia

- Peritonitis (bowel perforation)

Ix

- Stool MCS

- As per presentation

Mx

- Abx

- Increasing resistance

- Amoxycillin

- Cephalexin

- Trimethoprim & Sulfamethoxazole

- Nitrofuranatoin

- Aminoglycosides