Tuberculosis Flashcards
What are the characteristics of Mycobacterium tuberculosis?
Aerobic
Acid fast rods
intracellular* (resides inside cells and therefore evades phagocytes )
Tell me about the cell wall of mycobacterium tuberculosis?
Cell wall contains mycolic acid
What is so great about the mycolic acid in the cell wall of mycobacterium tuberculosis?
resistant to detergents and common antibiotics
protected from desiccation
Which one has a CELL WALL: mycobacterium tuberculosis or mycoplasma pneumoniae?
Mycobacterium tuberculosis = CELL WALL
Mycoplasma pneumoniae has NO cell Wall
What does the Acid fast stain of the mycobacterium tuberculosis look like?
Teal green background fusha colored
Explain the virulence of Mycobacterium tuberculosis?
cord factor (bacteria clump together and form a rope like arrangement)
(but the actual damage (tissue necrosis) is caused by our own immune system response ,not the cord factor)
How does transmission work with Mycobacterium tuberculosis?
you inhale the bacteria, likes to live in the lungs!
symptoms don’t appear for 4-12 weeks - slow grower
What are the presenting symptoms of tuberculosis?
Productive cough (sputum may be bloody) Weight loss (like a lot) Sweating Mild fever Fatigue Malaise
How many types of tuberculosis are there?
3
explain each type of tuberculosis:
Primary tuberculosis
Secondary tuberculosis
Disseminated tuberculosis
Primary tuberculosis – initial case of tuberculosis disease
Secondary tuberculosis – Can go dormant in your lungs – your immune system keeps it in check, but if your immune system is weakened its reactivated
Disseminated (Miliary) tuberculosis – tuberculosis involving multiple systems (for example gets into blood and spreads to lungs - not good!)
what do we mean that tuberculosis lives intracellularly?
It’s inhaled, engulfed by alveolar macrophages BUT survives and multiplies by attracting and activating more macrophages
Forms tubercles or granulomas which allow the bacteria to wall itself off and remain protected from the immune system
Can this bacteria become dormant?
-can remain dormant for years to decades!
then when the immune system is weakened, it comes back!
How does tuberculosis change over time?
CASEOUS LESION: when its inhaled into alveoli its a cheese like consistency.
GHON COMPLEXES: When it moves into the lung and lymph node it becomes calcified (can see this in a chest XRAY)
TUBERCULOUS CAVITIES: Tubercule ruptures and liquifies and forms an air filled cavity with from which bacteria can spread throughout the body
TUBERCULOUS CAVITIES:
lead to the:
reactivation tuberculosis and miliary tuberculosis
Diagnostics: culture tuberculosis
Lowenstein Jensen Agar
-grows slow (like 6 to 8 weeks)
