Lecture 4 - Tuberculosis & Leprosy Flashcards
In what species is M. Tuberculosis found?
Only in humans
Species for M. Bovis?
Only in cows, rarely in humans
M. avium symptoms
TB like symptoms especially in those with AIDs
M. leprae causes
Leprosy in humans
M. TB is what kind of pathogen
Obligate human pathogen
Where does TB live in our body?
In macrophages
Is TB generation time fast or slow
Very slow
Why does the cell envelope look waxy?
Lots of mycelia acid
What si the use of mycolic acid?
Causes high resistance for TB and is impermeable to stains and dyes
What test can we use to determine the presence of mycolic acid?
G+ acid fast stain
For acid fast stain, what colour is positive?
Red, blue is negative
How many stages of TB are there?
3
TB Stage 1
Inhaled into the lungs
TB Stage 2
Happens 1-3 weeks after exposore. Phagocytosis is occurring in lungs and release more TB
TB Stage 3
Granulomas begin to form from macrophages. Lysosome fusing is inhibited and activated macrophages try to kill off TB. T cells try to start activating granuloma but it’s usually too big
How do we test for TB?
Using a tuberculin test (protein purified derivative)
What is a positive TB test?
Red swollen spot 48 hours after injection
What is a definitive TB positive test?
When a patient goes from being neg - poz
What does a negative TB test mean?
- not infected
- highly immunocompromised
- very recently infected
What does a positive TB test mean?
- latent or active form of TB
- BCG vaccine was used previously
Is TB treatment fast or slow?
VERY SLOW
What drugs are used to treat TB?
Rifampicin and isoniazid
What is the BCG Vaccine
It’s a living vacuuming from M. bovid, variable effectiveness and causes TB test to be positive
What effect does having HIV have on contraction of TB
x30 more likely, leading killer of HIV patients
Is leprosy fast or slow?
EXTREMELY SLOW
What physical changes occur when leprosy is contracted/
Damage to skin, nerves, limbs and eyes
How can leprosy be dianosied
Using our G+ ACID FAST STAIN!
Which is more infective, TB or leprosy?
TB
What is Tuberculoid Leprosy
Cell mediated immunity response where the macrophages consume the bacteria
What is Lepromatous Leprosy
No cell mediated immune responses and macrophages remain inactive. Disease survives and multiples
How is leprosy treated?
With long term use of antibiotics
