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

 

E.Coli