Mycobacterium

Question 1

mycobacterium tuberculosis bacteriology

Answer 1

long, skinny, straight or curved
complex structure- stained with acid fast bacilli
slow growing
obligate aerobe
facultative intracellular

Question 2

mycobacterium tuberculosis virulence factors

Answer 2

complex cell wall
intracellular- hides from immune system
siderophores
chromosomal mutations
inhibition of phagosome-lysosome fusion

Question 3

complex cell wall of TB does

Answer 3

resists phagocytosis
impermeable- disinfectant and antibiotic resistance
resists drying

Question 4

what proteins prevent phagosome-lysosome fusion

Answer 4

ESAT-6

CFP-10

Question 5

3 forms of TB

Answer 5

primary
secondary
disseminated, extrapulmonary

Question 6

Ghon complex

Answer 6

calcified caseous granuloma filled with bacteria

Question 7

immune response

Answer 7

CD4 cells activated and release INFgamma nd TNF alpha which activate macrophages
macrophages release cytokines (TNF, IL1, IL6, IL8) that lead to inflammation

Question 8

cells in a granuloma

Answer 8

macrophages
fibroblasts
lymphocytes
neutrophils

Question 9

marker of latent TB

Answer 9

Ghon complex

Question 10

secondary TB

Answer 10

reactivation of bacteria in Ghon complex in immunosuppressed states OR re-infection by exogenous bacteria

Question 11

sites of dissemination of TB

Answer 11

lymph nodes
kidneys
bones
genital tract
brain
anywhere

Question 12

symptoms of active TB

Answer 12

fever
weight loss
night sweats
cough
bloody sputum
fatigue
decreased appetite

Question 13

diagnosis of active TB

Answer 13

abnormal CXR
positive PPD
acid fast bacilli from sputum sample
culture

Question 14

TB is commonly with

Answer 14

HIV

Question 15

active TB treatment

Answer 15

rifampin
isoniazid
pyrazinamide
ethambutol/streptomycin
6-24 months

Question 16

diagnosis of latent TB

Answer 16

PPD- intrepretation depends on risk factors

Question 17

5mm positive if

Answer 17

HIV infected
close contact with infectious case
CXR consistent with prior untreated TB
organ transplants
immunosuppressed

Question 18

10mm

Answer 18

clinical conditions that make them high risk

kids

Question 19

15mm

Answer 19

no known risk factors

Question 20

treatment of latent

Answer 20

chemoprophylaxis with 1 or 2 drugs

Question 21

BCG vaccine

Answer 21

avirulent strain that is missing ESAT-6 and CFP-10
used in endemic countries
prevents it in kids
doesn’t stop reactivation of latent infections

Question 22

mycobacterium avium complex

Answer 22

major cause of death in AIDS patients

in dirt and water

Question 23

MAC colonoizes

Answer 23

GI tract or respoiratry tract and then spreads

Question 24

MAC symptoms`

Answer 24

diarrhea
fatigue
fever
wasting

Question 25

m fortuitum

Answer 25

opportunistic pathogen
widely in environment
skin lesions, abscesses

Question 26

M leprae

Answer 26

causes leprosy- chronic, progressive disease of skin and nerves

Question 27

m leprae grows in

Answer 27

armadillos
schwann cells
macrophages

Question 28

tuberculoid description

Answer 28

less severe

Th1

Question 29

lepromatous description

Answer 29

severe
TH2
sensory nerve damage –> injury and secondary infection

Question 30

diagnosis leprosy

Answer 30

microscopic exam
history
symptoms- numbness, loss of temp sensitivity

Question 31

leprocy tuberculoid treatment

Answer 31

dapsone

rifampin

Question 32

lepromatous treatment

Answer 32

dapsone
rifampin
clofazimine