Microbiology of TB

Question 1

what is TB

Answer 1

an infection caused by Mycobacteria tuberculosis

Question 2

what organ does it primarily affect

Answer 2

the lungs

Question 3

what other organs can also be infected other than the lungs

Answer 3

kidney, spine, brain

Question 4

what is the main bacteria species that causes TB

Answer 4

Mycobacteria tuberculosis

Question 5

what other bacteria commonly cause TB

Answer 5

Mycobacterium africanum - common in west African countries

Mycobacterium bovis - unpasteurised cow’s milk (uncommon in UK)

Question 6

what myobacterium causes leprosy

Answer 6

Mycobacterium leprae

Question 7

mycobacteria: what is the rate of growth of mycobacteria

Answer 7

very slow

Question 8

mycobacteria: what affect does rate of growth have on treatment length

Answer 8

longer treatment

Question 9

mycobacteria: aerobic or anaerobic

Answer 9

aerobic

Question 10

mycobacteria: common location in lung

Answer 10

apices

Question 11

mycobacteria: how is it stained

Answer 11

Ziehl Neilson Stain

Question 12

mycobacteria: another name for bacteria causing TB

Answer 12

acid and alcohol fast bacilli (AAFB)

Not all AAFBs are TB

Question 13

how is TB spread

Answer 13

airborne - must have TB in lungs or URT to spread

Question 14

what increases risk of transmission

Answer 14

close contact for prolonged time (>8 hrs)

Question 15

what is the most infections type of TB

Answer 15

laryngeal TB

Question 16

how is TB not spread

Answer 16

• shaking hands
• sharing food
• touching surfaces
• sharing toothbrush
• kissing

Question 17

what type of bacteria is exempt from the usual route of spread

Answer 17

M. Bovis which is spread by consumption of unpasteurised cow’s milk