Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
47 Cards in this Set
- Front
- Back
Morphology of Actinomycetales? |
G+, catalase positive, aerobic
|
|
What is MAC? (attack)
|
Mycobacterium avium intracellulare complex
|
|
Where is MAC (attack) and Nocardia found? |
found in soil, water, decaying vegetation
|
|
What are the 3 Acid fast bacteria with mycolic acid in their cell walls?
|
Mycobacterium
Nocardia Corynebacterium |
|
What are the two most common causes of infection by nontuberculous mycobacteria?
|
MAC (attack)
Mycobacterium kansasii |
|
What is the most common mycobacterial infection in AIDS pts?
|
DMAC (daddy)
|
|
What is the morphology of Actinomyces israelii?
|
Anaerobic, G+, rod
|
|
How do you differentiate between M. avium and M. intracellulare?
|
DNA/RNA probes
|
|
What is the morphology of M. avium and M. intracellulare?
|
Gram Positive, Aerobic bacilli
Very acid fast |
|
How fast does MAC grow?
|
slow- 10-12 hour doubling time
|
|
What aer the most common sources of MAC?
|
cigarettes
Homes and hospitals |
|
What temp does MAC grow best in?
|
41C
|
|
Where does MAC grow best?
|
intraceullular growth
|
|
What actually causes damage in MAC infections?
|
host response to infection
|
|
What is MAC resistant to?
|
This is resistant to disinfection, NOT killed by chlorination
|
|
How does MAC get in the body?
|
inhalation or ingestion with food/water (hot water/showers)
|
|
Does MAC get transmitted person to person?
|
NO way jose
|
|
Where is MAC distributed?
|
worldwide !
|
|
Who can get pulmonary MAC?
|
everyone, NON HIV, HIV, immunosuppressed or not!
|
|
What are MAC infections usually due to?
|
primary/new infections
|
|
How does the initial infection of MAC occur?
|
This invades across the mucosa of the lungs or GI
Infects Resting macrophages spreads to submucosa and lymphatics |
|
Where can MAC travel in AIDS pts?
|
Liver, spleen, Bone, all over!
|
|
What kind of MAC do immunocompetent people, with underlying lung disease- get?
|
Pulmonary MAC
(fibrocavity disease, Fibronodular disease) |
|
What is fibrocavity disease? who gets it? what part of lung?
|
pulmonary MAC-
upper lobe disease in elderly male smokers. difficult to diagnose MAC recovered from sputum |
|
What is fibronodular disease? who gets it? what part of lung?
|
Fastidious elderly women +50 years. NON smoker. Who suppresses cough reflex
Middle/Lingular lobe Called Lady Windermeres syndrome |
|
Why usually gets Lymphadenitis from MAC? where?
|
kids 1-4 years old
usually involves unilateral cervical lymph nodes |
|
Who usually gets DMAC? signs?
|
AIDS pts with CD4 of less than 50 cells/micro liter
FUO, diarrhea, dyspena, upper right quadrant pain |
|
Where does DMAC go in the body?
|
this is not contained by granulomas, so it spreads to any organ or tissue.
causes enlarged and dysfunctional organs |
|
is MAC/DMAC reportable?
|
NO! unless its for AIDS pts
|
|
How do you diagnose MAC?
|
you must r/o fungals
presentation must be consistent with nontubercular mycobacterium Sterile site isolation is significant |
|
How do you treat MAC?
|
3 drug therapy (for both HIV and normal people)
Macrolides + ethanbutol and rifabutin |
|
How long do you treat MAC for?
|
1 year minimum or until 12 months after sputum is negative for MAC
|
|
What kind of chemoprophylatcitc is given for HIV pts against MAC?
|
clarithromycin, azithromycin
|
|
Where is nocardia found in the world?
|
worldwide, in the soil
|
|
What is the morphology of nocardia?
|
Acid Fast
Gram Positive Aerobic form Branched hyphae in tissues and cultures Catalase + |
|
What is the colony morphology of nocardia?
|
Dry to waxy
White to orange distinct growth patterns @ 35-45C |
|
How do you identify nocardia?
|
16s rRNA-based PCR
and Restriction Fragment Length Polymorphism |
|
What are the virulence factors of nocardia?
|
intracellular growth
disease comes from host response resistant to disinfection |
|
Where does nocardia usually come from?
|
exogenous infection from SOIL.
|
|
Who usually gets nocardia?
|
immunocompromised pts in hospitals
OR pts with underlying pulmonary conditions |
|
Where is nocardia most prominent ?
|
the dry warm climates of the southwest.
the dry dusty windy conditions facilitate the aerosolization |
|
Are infections transmitted from person to person?
|
NO they are not
|
|
What are the 3 greatest risks for developing Nocardiosis?
|
T-cell deficiencies
Chronic pulmonary diseases Bronchopulmonary infections |
|
What are the signs of Nocardiosis?
|
similar to pyogenic, but develops slowly
dyspnea, fever Cavitation/spread to pleura Dissemination into CNS or subcue tissues (brain abscess?) |
|
How do you diagnose Nocardiosis?
|
Gram stain (G+)
Acid fast stain (ziehl-neelsen stain) Decoloried by 1% H2SO4 means it is weak acid fast Culture Slow 1 week |
|
What medium do you grow Nocardia on?
|
Selective BCYE
or Modified Thayer-Martin |
|
What is the drug of choice for Nocardiosis?
|
Trimethoprim, sulfamthoxazole (TMP/SMX)
use 2-3 antibiotics for 3-6 weeks (IV if needed) |