hard topics (e coli, digestive protozoans and hepatitis viruses)

Question 1

Epidemic E coli (especially in infants) is associated with

Answer 1

Enteropathogenic E. coli

Question 2

EPEC is

Answer 2

Invasive, non-toxigenic

Question 3

Traveler’s diarrhoea is associated with

Answer 3

Enterotoxigenic E coli

Question 4

ETEC is

Answer 4

non-invasive, toxigenic

Question 5

Which toxins are produced by ETEC

Answer 5

Labile LT toxin and stable ST toxin

Question 6

Enteroinvasive E. coli causes what symptom and has a mechanism similar to which bacteria

Answer 6

bloody diarrhoea, invades epithelial cells, similar to Shigella

Question 7

EIEC is

Answer 7

invasive, non-toxigenic

Question 8

EHEC is

Answer 8

invasive, toxigenic

Question 9

What conditions is EHEC associated with

Answer 9

Haemorrhagic colitis, haemorrhagic diarrhoea, haemolytic uraemic syndrome

Question 10

What is the most important strain of EHEC

Answer 10

O157H7

Question 11

What toxin is produced by EHEC

Answer 11

Vero-toxin (similar to Shiga toxin- shiga like toxin)

Question 12

What symptoms are caused by enteroaggregative and enteroadhesive e. coli?

Answer 12

Watery diarrhoea

Question 13

What toxin is produced by enteroaggregative e. coli

Answer 13

ST (same as enterotoxigenic e coli)

Question 14

Are enteroadhesive and enteroaggregative e coli invasive? Differentiate between the appearance of the two in the GI tract

Answer 14

Agg = stacked brick
Adhesive = single layer of bacterial cells that coats mucosa
No they are not invasive

Question 15

Hepatitis A transmission

Answer 15

Faecal-oral (food contaminated by faeces)

Question 16

Hepatitis A structure

Answer 16

No envelope, ss RNA

Question 17

Hepatitis A causes damage to

Answer 17

Liver, kidneys and spleen

Question 18

Hepatitis B structure

Answer 18

ds DNA, envelope

Question 19

Hepatitis B transmission

Answer 19

Blood (contaminated equipment, nonsterile needles) and bodily fluids (semen, breast milk, saliva), transplacental

Question 20

Who is at high risk of contracting HBV

Answer 20

Health care workers

Question 21

Complications of Hepatitis B

Answer 21

Liver cirrhosis and cancer

Question 22

How is hepatitis B cultured

Answer 22

Cultured in yeast cells

Question 23

Hepatitis C structure

Answer 23

ssRNA, envelope

Question 24

How is Hepatitis c transmitted

Answer 24

Mostly in blood (organ transplant and injection equipment), can occur less commonly by sexual contact

Question 25

What are the complications of chronic Hepatitis c infection

Answer 25

Liver cirrhosis and cancer

Question 26

Hepatitis D structure

Answer 26

ss RNA, technically no envelope (acquires envelope from HBV)

Question 27

Hepatitis e structure

Answer 27

No envelope, ss RNA

Question 28

Hepatitis E transmission

Answer 28

faecal oral

Question 29

How is hepatitis E relevant to pregnant women?

Answer 29

Causes 20% mortality in this group of people

Question 30

Does Hepatitis E cause liver disease

Answer 30

No