Week 13: Infections of GIT

Question 1

What is the selective medium used for salmonella?

Answer 1

Selenite broth

Question 2

What is CAMP used to detect?

Answer 2

Campylobacter

Question 3

What happens if you give someone antibiotics for salmonella typhimurium?

Answer 3

Shiga toxin is phage-encoded, so antibiotics should NOT be administered

Question 4

What is the gold standard for identifying S. Typhi?

Answer 4

Molecular typing

Question 5

What does bloody diarrhea indicate?

Answer 5

Invasion of the intestinal mucosa

Question 6

On a DCA plate, what does a lactose fermenter exclude?

Answer 6

Salmonella and Shigella

Question 7

What is haemolytic uremic syndrome characterised by? (3)

Answer 7

Haemolytic anaemia
Acute renal failure (uremia)
Thrombocytopaneia

Question 8

What is a differential diagnosis for coeliac disease? How can we distinguish between the two?

Answer 8

Giardia lamblia

Can check for cysts in iodine stained mount (asymptomatic excretion is common though)

Question 9

What could vomiting and watery diarrhea indicate in a baby (if no abnormal findings are found on examination)?

How can we treat it?

Answer 9

Rotavirus

Rehydration, use a vaccine to prevent

Question 10

What are the most important markers for viral hepatitis?

Which are more numerous?

Answer 10

ALT (liver specific)
AST (found in cytoplasm and mitochondria)

Usually ALT>AST

Question 11

What can a positive HBs Ab indicate?

Answer 11

Previous infection or immunisation against Hep B

Question 12

What would we see in an acute/recent infection of Hep A (serology)?

Answer 12

HAV Ab (IgG): Positive, high
HAV Ab (IgM): Positive