Module 3

Question 1

Approximately what proportion of the worldwide population is infected with mycobacterium tuberculosis?

Answer 1

1/4

Question 2

What percentage of people infected with mycobacterium tuberculosis develop disease?

Answer 2

5-10%

Question 3

How many main phylogenetic lineages of mycobacterium tuberculosis exist?

Answer 3

6

Question 4

Which two leucocytes are most important in immunology of tuberculosis?

Answer 4

Macrophages and CD4+ Th1

Question 5

Give three features that characterise a caseating (as opposed to non-caseating granuloma)

Answer 5

Avascular necrosis
Imbalance of cytokines e.g. TNF-alpha
Inflammation/ necrosis instead of apoptosis
Pathogen escape from necrosed phagocytes

Question 6

Children infected with Tb are not considered infectious

True or false?

Answer 6

True

Children tend to have a lower bacterial load and so are not considered infectious

Question 7

What property of mycobacterium tuberculosis cell walls makes them hydrophobic?

Answer 7

High lipid concentrations