Tuberculosis

Question 1

List the different mycobacterium causes of TB. Also state the types of conditions required for each type 2 cause TB

Answer 1

Mycobacterium tuberculosis: main cause of TB in humans

Mycobacterium bovis: main cause of TB in cattle and other mammals, can cause human disease

Mycobacterium africanum: primarily seen in west Africa

Mycobacterium microti: mainly affects other mammals

Question 2

Describe 3 main features of Mycobacterium

Answer 2

Obligate aerobes: they require oxygen to grow.

Facultative intracellular: can grow outside the cell but find it advantageous to be intracellular.

Acid fast bacilli (AFB): refers to a resistance to decolourisation of staining by acid.

Question 3

Once someone has been infected with TB describe the 5 clinical pathways the condition can progress

Answer 3

Immediate clearance

Primary TB - initial infection, subclinical, suppressed in most people

Progressive primary TB - primary infection not suppressed. Prolonged infection occurs