Tuberculosis (TB) Mycobacterium Flashcards
What shape can TB be classified as, shape wise?
1 - spheres (cocci)
2 - rods (bacilli)
3 - spirals
4 - none of the above
- bacillus (rod shaped)
Is TB aerobe or anaerobe?
- aerobe, hence why is likes the lungs
Does TB possess a cell wall?
- yes
- gives bacterial its waxy surface (mycolyic acid)
- but no phospholipid outer membrane
Does TB divide quickly or slowly?
- slowly
- every 16-20 hours
Mycobacterium tuberculosis (TB) is an aerobic pathogenic bacteria, hence its affinity for the lungs. Is TB Gram + or Gram -?
- typically a weak Gram + due to the waxy cell coating
- mycolic acid in cell wall gives TB waxy coating
Atypical non-mycobacteria is a part of mycobacterium family (cousin of TB and is an opportunistic bacteria. Does atypical non-mycobacteria infect as many people as standard TB?
- no
- typically affects effect immunocompromised patients
Is there an interaction between TB and HIV?
- yes
- immunocompromised patients are more likely to be infected with TB
- HIV patients have low CD4+ T cells
- HIV patients are unable to mount an immune response against TB
Why is TB more common in big cities?
1 - more close to close contact
2 - TB can undergo genetic drift and infect more people
3 - larger diversity from all parts of the world
4 - all of the above
3 - larger diversity from all parts of the world
- more diversity means more people from all over the world
- majority of TB patients in UK, are born outside UK
All of the following patients are at greater risk of developing TB, EXCEPT which ones?
1 - deprivation (malnourished, overcrowding) - 2 - alcoholics
3 - prison inmates
4 - females
5 - immunocompromised (elderly, infants)
6 - high risk groups/jobs (airport staff)
4 - females
- men and women are equally affected
How is TB transmitted?
1 - sexual contact
2 - aerosols and direct contact
3 - shared food only
4 - dirty water
2 - aerosols and direct contact
- 80% affects lungs
Once inside the lungs TB is able to spread through a specific type of immune cell. Which immune cell is this?
1 - B cells
2 - dendritic cells
3 - CD4 T cells
4 - macrophages
4 - macrophages
- engulf TB and attempt to phagocytose
- if no phagocytosis, TB replicates in endosome
Mycobacterium tuberculosis (TB) is an aerobic pathogenic bacteria, hence its affinity for the lungs. What is the estimated global incidence of TB?
1 - 9 / 100,000
2 - 90 / 100,000
3 - 900 / 100,000
4 - 9000 / 100,000
1 - 9 / 100,000
- estimated to affect 10 billion/year
Mycobacterium tuberculosis (TB) is an aerobic pathogenic bacteria, hence its affinity for the lungs. What age does the TB occurrence peak in?
1 - 20-30
2 - 20-40
3 - 30-50
4 - 50-60
4 - 50-60
Mycobacterium tuberculosis (TB) is an aerobic pathogenic bacteria, hence its affinity for the lungs. Does TB affect more men or women?
- both equally affected
How many people each year are estimated to die from TB each year?
1 - 1500
2 - 15,000
3 - 150,000
4 - 1.5,000,000
4 - 15,000,000
- 1.5 billion die from TB each year
Are patients with TB, active or inactive infectious?
- no
- latent = non-infectious
- active = infectious
If you suspect a patient has active TB, what disease must also be screened for?
1 - diabetes
2 - SLE
3 - HIV
4 - vasculitis
3 - HIV
- TB affects those who are immunocompromised
Although TB affects lots of people, what % of TB is actually active?
1 - 40-50%
2 - 20-30%
3 - 10-20%
4 - 5-10%
4 - 5-10%
Once TB has been inhaled into the lungs there are lots of host defences that try to eradicate TB. Which of the following are innate host defences against TB?
1 - mucocillary escalator
2 - turbulent air flow causes TB to get stuck in mucus
3 - macrophages
4 - all of the above
4 - all of the above
Once inside the lungs, if the macrophages are unable to phagocytose TB, the patient now has primary TB. Do they present with symptoms immediately?
- no
- some patients can be asymptomatic and others can have mild flu like symptoms
Once inside the lungs, if the macrophages are unable to phagocytose TB, the patient now has primary TB. After aprox 3 weeks after being infected, cell mediated immunity begins and does what to the TB?
1 - immune cells kill off all TB cells
2 - immune cells surround TB and form a granuloma without caseous necrosis
3 - immune cells surround TB and form a granuloma with caseous necrosis
4 - all of the above
3 - immune cells surround TB and form a granuloma with caseous necrosis
Once inside the lungs, if the macrophages are unable to phagocytose TB, the patient now has primary TB. After aprox 3 weeks after being infected, cell mediated immunity begins and immune cells surround TB and form a granuloma with caseous necrosis. What is this called?
1 - hyperplasia
2 - ghon focus
3 - TB cyst
4 - pleural effusion
2 - ghon focus
TB can affect which lymph nodes in the thoracic cavity?
1 - intercostal lymph nodes
2 - juxtavertebral lymph nodes
3 - hilar lymph nodes
4 - brachiocephalic lymph nodes
3 - hilar lymph nodes
- could affect any lymph nodes but these are the most commonly affected
Is bilateral hilar lymphadenopathy specific to TB or sarcoidosis?
- present in both