Exam 4 Pathogeneic factors of Gastrointestinal diseases

Question 1

What is SopE and how does it work?

Answer 1

SopE is secreted into M cells of the intestinal lining and then SopE induces release of actin-dependent ruffles which then take in Salmonella.

Question 2

How does LT (AB) toxin work?

Answer 2

Heat-liable toxin binds to GM1 gangliosides which then cause ADP ribosylation of G proteins. leads to increased levels of cAMP and increased secretion.

Question 3

How does ST small peptide work?

Answer 3

The enterotoxin binds to guanylate cyclase receptors which increase cGMP acculation intracellularly. Leads to increased secretion

Question 4

How do shigatoxin works

Answer 4

The toxin attacks ribosomes inhibiting protein synthesis and binds GB3.

Question 5

What is the Vi antigen responsible for and on what organism is it on?

Answer 5

The Vi antigen inhibits oxidative killing when the S. Typhi enters macrophages and is able to reproduce intracellularly. they also invade epitheial cells via invasin.

Question 6

What are SEB toxins?

Answer 6

Heat, protease, acid stable superantigens.

Question 7

What is NSP4

Answer 7

They induce secretion in viral gastroentertidis. leading to dehydration.