PCR prac

Question 1

What was the point of this prac?

Answer 1

People had E. Coli from chicken (poultry sourced from 2 farms)
Want to work out where it came from

Question 2

What disease causing strain from both farms was found?

Answer 2

CB1

Question 3

How is virulence in CB1 mediated?

Answer 3

Expression of vir operon, which is repressed by action of the ViR protein

Question 4

What does ViR protein do?

Answer 4

Binds to and occludes -10 site of vir operon sigma-70-binding promoter
It also contains a ligand-binding domain and in the presence of an inducer ViR dissociated from DNA and transciption of the ViR operon proceeds

Question 5

What is CB1 serovar OX2?

Answer 5

It carries a wild-type gene for ViR and exists harmless in the gut for some people

Question 6

What is CB1 serovar PaIN?

Answer 6

Carries a small insertion that disrupts ViR reading frame and disrupts the ViR reading frame, inactivating the ViR protein so that pathogenicity factors are expressed
ViR operon transcription no longer repressed