E.Coli

Question 1

What is E.Coli?

Answer 1

• Gram Negative Faculative anerobic rod shaped bacterium
• 4500-5500 genes
• They frequently carry plasmids
• Zoonotic
• Economically important pathogen in humans and livestock

Question 2

What is colonisation?

Answer 2

presence of a microorganism in a host but without any interaction between the host and the organism?

Question 3

Why is E.Coli Pink on a MacConkey agar plate

Answer 3

E.Coli is lactose fermenting

Question 4

What are strains of E.Coli Classified into?

Answer 4

Pathotypes

Question 5

Name 5 determinants of E.Coli Virulence

Answer 5

• Fimbriae/ Flagella
• Outer Membrane Proteins
• Plasmids
• Acid Resistance
• Serum Resistance

Question 6

What are some features Enteropathogenic Bacteria (EPEC)

Answer 6

Pedestals with long fimbriae

Question 7

What are three diseases caused by ETEC? (Enterotoxigenic E. coli)

Answer 7

Colisepticaemia, Watery mouth, Neonatal diarrhoea (white scours)

Question 8

What are the two toxins that ETEC contains?

Answer 8

• Heat labin toxins
• Heat stable toxins

Question 9

Why would different ETECs have different susceptabilities over time?

Answer 9

Receptors of the fimbriae change over time

Question 10

What are three diseases Extra Intestinal E.coli causes?

Answer 10

• Coliform mastitis
• Colisepticaemia
• Meningitis

Question 11

What does APEC effect predominantly?

Answer 11

• affects young birds, predominantly 4-12 weeks old

Question 12

What are some determinants of the APEC virulence?

Answer 12

• Fimbriae
• Flagella
• Serum resistance
• Acid resistance

Question 13

What are some pre-disposing factors for avian colisepticaemia?

Answer 13

• Stress
• Husbandry practices
• Build up of ammonia
• Mycoplasmal infections

Question 14

What are some features of Verotoxigenic E.Coli?

Answer 14

• Most strains are motile
• Most strains are non-sorbitol fermenters
• They harbour stx toxins
• harbour large virulence plasmids

Question 15

What do Vero-Toxigenic diseases look like in pigs?

Answer 15

• Oedema disease
• Sudden death
• Oedema of the forehead, eyelids, stomach wall and larynx
• Ataxia, paralysis and convulsions

Question 16

Approximately how many cases of vero-toxigenix bacteria are there in the UK each year?

Answer 16

1100 human cases

Question 17

What meat is the main source of vero-toxaemia in humans?

Answer 17

Ground beef

Question 18

What are some routes of infection for vero-toxigenic E.Coli?

Answer 18

• Untreated manure
• Meat
• Can bind to plant leaves

Question 19

What is the type III secretion system?

Answer 19

A way of the bacteria injecting proteins into host cells

Question 20

Why would you tie off a cows rectum after slaughter?

Answer 20

Prevents manure from exiting the cow

Question 21

What could you use to culture E.coli?

Answer 21

• Blood agar
• Nutrient/ LB agar
• MacConkey Agar
• Chromogenic Agar

Question 22

What may determine E.coli virulence?

Answer 22

• Fimbriae/Flagella
• TTSS
• Outer Membrane Proteins
• Acid Resistance
• Serum Resistance
• Pathogencity islands

Question 23

What does E.Coli cause in piglets?

Answer 23

• Neonatal diarrhoea
• Weaning enteritis
• Colibacillosis
• Colisepticaemia

Question 24

What does E.Coli cause in lambs?

Answer 24

• Colibacillosis
• Colisepticaemia
• Watery mouth

Question 25

What is the pathogenesis of travellers diarrhoea in humans?

Answer 25

* Ingestion of Pathogenic E.Coli * Colonisation of the jejenum and illeum * Water and Electrolytes * Diarrhoea, Weight loss, Death

Question 26

What age of pigs appear to be resistant to infection?

Answer 26

Pigs older than 8 weeks

Question 27

What is Hjarres disease?

Answer 27

granulomas in the intestinal tract, liver and mesentry

Question 28

What are vero-toxins?

Answer 28

toxic metabolites produced by fungi