Lecture 8E - Mycobacterium Species (Dr. Daniels)

Question 1

Which 3 types of diseases are caused by Mycobacterium species?

Answer 1

1. Tuberculosis
2. Leprosy
3. Opportunistic diseases caused by Rapidly Growing Mycobacteria (RGM)

Question 2

Which species of Mycobacterium cause tuberculosis?

Answer 2

1. M. tuberculosis (HIGHLY CONTAGIOUS)
2. M. bovis (why we pasteurize milk)
3. M. avium-intracellulare

Question 3

M. ______ causes leprosy.

Answer 3

M. leprae (CONTAGIOUS)

Question 4

Who gets diseases from Rapidly Growing Mycobacterium?

Answer 4

tattooed people, plastic surgery, contaiminated deep wounds

Question 5

Mycobacterium are ______ aerobes.

Answer 5

obligate

Question 6

Do mycobacterium like oxygen?

Answer 6

They must have it. They are OBLIGATE AEROBES.

Question 7

What does a mycobacterium gram stain look like?

Answer 7

There are a bunch of smudges b/c they have a “waxy” cell wall which cannot absorb the dye.

Question 8

What makes a waxy cell wall on a mycobacterium?

Answer 8

MYCOLIC ACID residues in the peptidoglycan.

Question 9

Describe Mycobacterium species.

Answer 9

obligate aerobes
non-spore forming
thick, waxy cell wall
mycolic acid binds carbol fuscin dye

Question 10

Which type of stain do we have to use of Mycobacterium species?

Answer 10

Acid-fast stain

They are “acid-fast bacteria”

Question 11

We encounter mycobacterium by _______ or ______.

Answer 11

Ingestion, inhalation

Question 12

If adequate cell-mediated immunity is not carried out, Mycobacterium _____ _______ _ ______ _______.

Answer 12

can enter a latency period.

This can lead to reactivation, or secondary TB

Question 13

_________ form during TB

Answer 13

granulomas

Question 14

What are granulomas made of?

Answer 14

accumulation of macrophages

Question 15

True or False: US born people have a higher TB rate than Foreign-born people.

Answer 15

False

Question 16

How is TB Diagnosed? (4)

Answer 16

1. Intradermal skin test
2. Acid-fast sputum exam
3. Culture
4. PCR

Question 17

What is a TB intradermal skin test?

Answer 17

use of Purified Protein Derivative (PPD); killed antigen; “tuberculin”

relies on Delayed Type Hypersensitivity
-activation of CD4+ cells

Question 18

True or False: TB is a granulomatis disease, but Leprosy is not.

Answer 18

False. Both TB and Leprosy cause granulomas. They have a similar immunology.

Question 19

Where do the organisms live in leprosy?

Answer 19

skin (lower temp environment than internally)

Question 20

How does leprosy spread? Where does it end up?

Answer 20

Spreads via the respiratory route

Ends up in skin

Question 21

What are the two forms of leprosy? Which is more severe?

Answer 21

1. Tuberculoid Leprosy

2. Lepromatous Leprosy (more severe)

Question 22

Which animal is a carrier of M. leprae?

Answer 22

Armadillo

Question 23

Tuberculoid Leprosy

Answer 23

milder
may be self limiting
few bacteria in lesions

Question 24

Lepromatous Leprosy

Answer 24

severe, disfiguring
many bacteria in lesions
Cell Mediated Immunity is significantly decreased

Question 25

Can M. leprae be cultivated in vitro?

Answer 25

No

can inoculated mouse footpad