E.Coli Flashcards
What is E.Coli?
- Gram Negative Faculative anerobic rod shaped bacterium
- 4500-5500 genes
- They frequently carry plasmids
- Zoonotic
- Economically important pathogen in humans and livestock
What is colonisation?
presence of a microorganism in a host but without any interaction between the host and the organism?
Why is E.Coli Pink on a MacConkey agar plate
E.Coli is lactose fermenting
What are strains of E.Coli Classified into?
Pathotypes
Name 5 determinants of E.Coli Virulence
- Fimbriae/ Flagella
- Outer Membrane Proteins
- Plasmids
- Acid Resistance
- Serum Resistance
What are some features Enteropathogenic Bacteria (EPEC)
Pedestals with long fimbriae
What are three diseases caused by ETEC? (Enterotoxigenic E. coli)
Colisepticaemia, Watery mouth, Neonatal diarrhoea (white scours)
What are the two toxins that ETEC contains?
- Heat labin toxins
- Heat stable toxins
Why would different ETECs have different susceptabilities over time?
Receptors of the fimbriae change over time
What are three diseases Extra Intestinal E.coli causes?
- Coliform mastitis
- Colisepticaemia
- Meningitis
What does APEC effect predominantly?
- affects young birds, predominantly 4-12 weeks old
What are some determinants of the APEC virulence?
- Fimbriae
- Flagella
- Serum resistance
- Acid resistance
What are some pre-disposing factors for avian colisepticaemia?
- Stress
- Husbandry practices
- Build up of ammonia
- Mycoplasmal infections
What are some features of Verotoxigenic E.Coli?
- Most strains are motile
- Most strains are non-sorbitol fermenters
- They harbour stx toxins
- harbour large virulence plasmids
What do Vero-Toxigenic diseases look like in pigs?
- Oedema disease
- Sudden death
- Oedema of the forehead, eyelids, stomach wall and larynx
- Ataxia, paralysis and convulsions
Approximately how many cases of vero-toxigenix bacteria are there in the UK each year?
1100 human cases
What meat is the main source of vero-toxaemia in humans?
Ground beef
What are some routes of infection for vero-toxigenic E.Coli?
- Untreated manure
- Meat
- Can bind to plant leaves
What is the type III secretion system?
A way of the bacteria injecting proteins into host cells
Why would you tie off a cows rectum after slaughter?
Prevents manure from exiting the cow
What could you use to culture E.coli?
- Blood agar
- Nutrient/ LB agar
- MacConkey Agar
- Chromogenic Agar
What may determine E.coli virulence?
- Fimbriae/Flagella
- TTSS
- Outer Membrane Proteins
- Acid Resistance
- Serum Resistance
- Pathogencity islands
What does E.Coli cause in piglets?
- Neonatal diarrhoea
- Weaning enteritis
- Colibacillosis
- Colisepticaemia
What does E.Coli cause in lambs?
- Colibacillosis
- Colisepticaemia
- Watery mouth
What is the pathogenesis of travellers diarrhoea in humans?
- Ingestion of Pathogenic E.Coli
- Colonisation of the jejenum and illeum
- Water and Electrolytes
- Diarrhoea, Weight loss, Death
What age of pigs appear to be resistant to infection?
Pigs older than 8 weeks
What is Hjarres disease?
granulomas in the intestinal tract, liver and mesentry
What are vero-toxins?
toxic metabolites produced by fungi
