TB And Non TB

Question 1

Name three types of mycobacteria

Answer 1

Leprae

Tuberculosis complex

Non tuberculosis mycobacteria

Question 2

Mycobacterial characteristics

Answer 2

+ rods

Nonmotile
No spores
No capsule

Obligate aerobe

Very slow growing (or not at all)

Question 3

Describe acid fastness

Answer 3

Holds on to RED phenolic dye

Result of MYCOLIC ACIDS

• long chain fatty acids
• most of cell weight

Question 4

How is M. Tuberculosis spread?

Answer 4

Person to person

Aerosolized droplet nuclei from cough
-can remain in air for hours

Question 5

What happens to TB once inhaled?

Answer 5

Infects, grows

Ingested by MACS

Stay alive

-> form Granuloma

Question 6

What are the two types of TB manifestations?

Answer 6

LATENT

• asymptomatic
• non-infectious

ACTIVE

• symptomatic
• infectious

Question 7

Name some clinical syndromes of TB

Answer 7

GHON lesion

• seen on x-Ray
• healed tissue

CAVITIES

• hole in lung
• contains lots of bacteria
• very infectious

MILIARY
-throughout lung

Question 8

How does HIV relate to TB?

Answer 8

HIV greatly enhances ability of TB to take hold

TB controlled by CD4 cells

HIV depletes CD4 cells

Latent -> active

Active -> more deadly

Question 9

How would you diagnose active TB?

Answer 9

ACID FAST BACILLUS smear

• same day results
• LIMITED sensitivity
• LIMITED specificity

CULTURE

• MORE sensitive
• MORE time (2-3 weeks)
• MORE labor
• MORE costs

NUCLEIC ACID AMP
-use tb specific probe

Question 10

How would you treat active TB?

Answer 10

4 RIPE for 2 months

INH/RIF for 2 months

Beware of resistance

Question 11

How would you diagnose latent TB?

Answer 11

Tuberculin Skin Test

• delayed hypersensitivity IV
• uses PPD
• 2-10 weeks after initial infection
• measure INDURATION
• cross reaction

INTERFERON GAMMA RELEASE ASSAY (IGRA)

• blood assay
• look for IFN response

Question 12

How would you prevent TB?

Answer 12

Quick diagnosis and isolation of infected patients

Continuously test high risk individuals (health workers)

Vaccine?

Question 13

Is there a TB vaccine?

Answer 13

why yes

Uses myco Bovis (cow TB)

Great for kids, ok for adults

Can cross react with PPD but not IGRA

Question 14

How are mycobacteria doing in the world?

Answer 14

Tuberculosis is pretty popular around the world

Leprae is falling globally

Question 15

How is Leprae transmitted?

Answer 15

Probably respiratory? Maybe breaks in the skin?

Only infects humans (and armadillos)

NEEDS A HOST

Question 16

What medium can you use to culture Leprae?

Answer 16

NONE

Can’t be cultured foo

Question 17

What are the two forms of Hansen’s Disease?

Answer 17

TUBERCULOID

LEPROMATOUS

Question 18

Main features of tuberculoid Hansen’s?

Answer 18

noncaseating granulomas

Few bacteria

Smear lesions negative

Flat, red, lesions

Positive skin test

Good prognosis

Question 19

Main features of Lepromatous Hansen’s?

Answer 19

Few granulomas

Lots of bacteria

Positive AFB smears

See large, thick nodules

Antibody mediated

Negative skin test

Bad prognosis

Question 20

How do you diagnose Hansen’s?

Answer 20

Gross appearance

Histological exam

Acid fast stains

Question 21

How are nontuberculous mycobacteria transmitte?

Answer 21

NOT person to person

Soil, water, animals

Question 22

Clinical significance Of NTM?

Answer 22

Often contaminant

Can colonize w/o disease

Opportunistic

Question 23

Who does NTM hit?

Answer 23

Children

Chronic Lung disease and smokers

Older, tall, thin women?