Mycobacteria

Question 1

Mycobacterium

morphology, etc

Answer 1

aerobic
non-spore forming
nonmotile
bacillus
acid-fast (mycolic acid)

Question 2

M tuberculosis

transmission/epi

Answer 2

1/3 of world pop has latent TB
transmissible person-to-person
inhaled droplets
establishes latency
time+ closed space

Question 3

M. tuberculosis

primary infection

Answer 3

asymptomatic
posterior apices
macrophage ingestion
local focus (Gohn)
hilar nodes (complex of Ranke)
delayed hypersensitivity
granuloma

Question 4

M. tuberculosis

primary progression

Answer 4

often asymptomatic
3 mos: miliary TB or meningitis
3-4 mos: TB pleurisy
up to 3 yrs: boint/joint/renal/ TB

Question 5

M. tuberculosis

active infection

Answer 5

fever, cough, night sweats
tissue hypersensitivity
apical TB cavitation
caseous necrosis
may be asymptomatic

Question 6

M. tuberculosis

reactivation

Answer 6

stress

Question 7

M. tuberculosis

risk

Answer 7

DM
ESRD
immunosuppression
cancer

Question 8

M. tuberculosis

PPD test parameters

Answer 8

>5mm HIV+, HIV? & IDU, fibrotic CXR,
 close relative, steroids
>10mm HIV- & IDU, high prev country,
underserved area, high risk medical, long-term care
>15mm everyone else

Question 9

M. tuberculosis

lab diagnostics

Answer 9

intial: direct sputum smear
acid fast or fluorescent test
conirm: egg/agar culture (5 days)

Question 10

M. tuberculosis

BCG vaccination

Answer 10

attenuated vacc
intradermal
can affect PPD test

Question 11

M. tuberculosis

latent treatment

Answer 11

isonazid (6-9 mos)
isonazid + rifapentine (3 mos)
rifampin (4 mos)

Question 12

M. tuberculosis

active treatment

Answer 12

RIPE intensive
isonazid+rifampin continuation
6-9 mos

Question 13

M. tuberculosis

HIV

Answer 13

note: often smear negative
HAART causes IRIS
tx even if latent
contra'd: rifamycins
CD4>50, tx w/in 2 wks
CD4<50, tx w/in 8-12 wks

Question 14

M. tuberculosis
resistance profiles
(MDR vs. XDR)

Answer 14

MDR: resist isonazid, rifampin
XDR: MDR plus fluoroquinolone, mycins

Question 15

Non-TB mycobacteria

morphology etc

Answer 15

grow slowly (generally)
environmental (water, soil)
NOT human-human transmission
nosocomial outbreaks
pseudo-outbreaks (tap water)

Question 16

Non-TB mycobacteria

rapid grower spp.

Answer 16

M. abscessus
M. fortuitum
M. chelonae
M. immunogenum

Question 17

Non-TB mycobacteria

slow grower spp.

Answer 17

M. avium
ulcerans
kansasii
xenopi
scrofulaceum
gordonae
genevase

Question 18

Non-TB mycobacteria
nosocomial infections
(causes)

Answer 18

surgical wounds, injections, LASIK,
pneumonia, central catheters
don’t tx empirically

Question 19

Non-TB mycobacteria
MAC
(clinical manifestations)

Answer 19

more common in SE
pulm dz elderly men with COPD
pulm dz in elderly non-smoking women
pulm dz with CF
hypersensitivity pneumoitis (hot tub lung)
disseminated dz in AIDS
lymphadenitis in children
AFB smear positive

Question 20

Non-TB mycobacteria
nodular MAC lung dz
(Pt profile/risks)

Answer 20

Pt profile:
taller, leaner, pectus excavatum, scoliosis, MV proplaps
CF mutations

Question 21

Non-TB mycobacteria

MAC hypersens pneumonitis

Answer 21

hot tub lung
dyspnea, cough fever
CXR diffuse infiltrates
positive cultures
tx: steroids, antimycobx, observation

Question 22

Non-TB mycobacteria

diagnosis

Answer 22

3 criteria, all met:
1) clinical sx w/o other etiology
2) abnormal CXR/HRCT (inflitrates, cavitation, bronchiectasis)
3) bacteriologic criteria (2 pos sputum culture OR
positive BAL culture OR pos biopsy of granuloma/AFB w/ NTM from sputum)
*BAL is bronchoalveolar lavage

Question 23

Non-TB mycobacteria

treatment, general

Answer 23

NOT empiric

12+ mos of tx

Question 24

Non-TB mycobacteria

MAC tx

Answer 24

clarithromycin+ethambutol+rifampin
mothly sputum cultures
tx until culture negative for 12 mos

Question 25

Non-TB mycobacteria | MAC w/ HIV/AIDS tx

Answer 25

CD4100 for 3 months | may experience IRIS from ART

Question 26

Non-TB mycobacteria M. kansasii (general)

Answer 26

more common in midwest and south tuberculosish probe available for culture dx increased risk for HIV with CD4<200

Question 27

Non-TB mycobacteria | M. kansasii tx

Answer 27

INH + ethambutol + rifampin for 12 mos cult neg

Question 28

Non-TB mycobacteria M. xenopi distribution

Answer 28

UK, Europe, Canada, China, rural

Question 29

Non-TB mycobacteria M. xenopi (clinical pres)

Answer 29

tuberculosish

Question 30

Non-TB mycobacteria M. xenopi (treatment)

Answer 30

clarithromycin+IRE for 12 mos cult neg

Question 31

Non-TB mycobacteria Lymphadenitis (cause, dx, tx)

Answer 31

``` MAC or scrofulaceum usually unilateral ddx: TB dx: fine needle aspiration tx: surgery, chemotherapy ```

Question 32

Non-TB mycobacteria M. marinum (cause, dx, tx)

Answer 32

low temp required for culture water, fish granulomatous nodular-ulcerative lesions (hands) dx: biopsy, culture tx: clarithromycin/rifampin +ethambutol for 4 mos

Question 33

Non-TB mycobacteria M. ulcerans (cause, dx, tx)

Answer 33

low temp required for culture Africa chronic cutaneous ulcers tx: debridement

Question 34

Non-TB mycobacteria M. haemophilum (cause, dx, tx)

Answer 34

low temp required for culture needs Fe risk: immunocompromised (HIV+, ESRD) sx: skin lesions on extremities, ulcerative/nodular culture from skin, blood tx: combo rifampin, clarithromycin, etc etc

Question 35

Non-TB mycobacteria rapid grower infx'n (general profile)

Answer 35

soft tissue infx'ns (all spp.) pulmonary infx'n (abscessus>fortuitum) no cavitation

Question 36

Non-TB mycobacteria M. fortuitum (cause, clinical pres)

Answer 36

furunculosis from nail salon | ear piercing infection

Question 37

Non-TB mycobacteria | M. fortuitum tx

Answer 37

1) susceptibility testing 2) clarithromycin + 2 from cipro, doxy, sulfaonamide 4-12 mos

Question 38

Non-TB mycobacteria | M. chelonae tx

Answer 38

1) susceptibility testing 2) clarithromycin + cipro/doxy/linezolid 4-6 mos

Question 39

Non-TB mycobacteria | M. abscessus tx

Answer 39

poor tx prognosis | period tx w/ clarithromycin + amikacin + cefoxitin

Question 40

Non-TB mycobacteria M. immunogenum (cause, tx)

Answer 40

rapid grower risk: IV, catheters, leukemia drug tx prognosis poor combination tx

Question 41

Non-TB mycobacteria M. leprae (general cause, dx)

Answer 41

``` cannot be cultured slow growing (5-20 yr incubation) risk: armadillos, India, Brazil transmission: droplets dx: acid fast bacillus, skin biopsy of cutaneous nerve ```

Question 42

Non-TB mycobacterium lepromatous leprosy (clin pres, tx)

Answer 42

mulitbacillary diffuse skin involvement: plaques, nodules facial deformity anergy tx: dapsone + rifampin + clofazimine 12 mos

Question 43

Non-TB mycobacteria tuberculoid leprosy (clin pres, dx, tx)

Answer 43

``` paucibacillary <5 skin lesions anesthesia, nerve involvement dx: skin tests tx: dapson + rifampin 6 mos ```