Lecture 8E - Mycobacterium Species (Dr. Daniels) Flashcards
Which 3 types of diseases are caused by Mycobacterium species?
- Tuberculosis
- Leprosy
- Opportunistic diseases caused by Rapidly Growing Mycobacteria (RGM)
Which species of Mycobacterium cause tuberculosis?
- M. tuberculosis (HIGHLY CONTAGIOUS)
- M. bovis (why we pasteurize milk)
- M. avium-intracellulare
M. ______ causes leprosy.
M. leprae (CONTAGIOUS)
Who gets diseases from Rapidly Growing Mycobacterium?
tattooed people, plastic surgery, contaiminated deep wounds
Mycobacterium are ______ aerobes.
obligate
Do mycobacterium like oxygen?
They must have it. They are OBLIGATE AEROBES.
What does a mycobacterium gram stain look like?
There are a bunch of smudges b/c they have a “waxy” cell wall which cannot absorb the dye.
What makes a waxy cell wall on a mycobacterium?
MYCOLIC ACID residues in the peptidoglycan.
Describe Mycobacterium species.
obligate aerobes
non-spore forming
thick, waxy cell wall
mycolic acid binds carbol fuscin dye
Which type of stain do we have to use of Mycobacterium species?
Acid-fast stain
They are “acid-fast bacteria”
We encounter mycobacterium by _______ or ______.
Ingestion, inhalation
If adequate cell-mediated immunity is not carried out, Mycobacterium _____ _______ _ ______ _______.
can enter a latency period.
This can lead to reactivation, or secondary TB
_________ form during TB
granulomas
What are granulomas made of?
accumulation of macrophages
True or False: US born people have a higher TB rate than Foreign-born people.
False
How is TB Diagnosed? (4)
- Intradermal skin test
- Acid-fast sputum exam
- Culture
- PCR
What is a TB intradermal skin test?
use of Purified Protein Derivative (PPD); killed antigen; “tuberculin”
relies on Delayed Type Hypersensitivity
-activation of CD4+ cells
True or False: TB is a granulomatis disease, but Leprosy is not.
False. Both TB and Leprosy cause granulomas. They have a similar immunology.
Where do the organisms live in leprosy?
skin (lower temp environment than internally)
How does leprosy spread? Where does it end up?
Spreads via the respiratory route
Ends up in skin
What are the two forms of leprosy? Which is more severe?
- Tuberculoid Leprosy
2. Lepromatous Leprosy (more severe)
Which animal is a carrier of M. leprae?
Armadillo
Tuberculoid Leprosy
milder
may be self limiting
few bacteria in lesions
Lepromatous Leprosy
severe, disfiguring
many bacteria in lesions
Cell Mediated Immunity is significantly decreased
Can M. leprae be cultivated in vitro?
No
can inoculated mouse footpad
