Pneumonia part 2 Flashcards Preview

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Flashcards in Pneumonia part 2 Deck (21):
1

Legionella is a

opportunistic facultative IC pathogen with variable infection outcome (requires silver or IF in tissue sections to see, also gram negative rods)

2

Exposure to legionella is from

aspiration or inhalation of contaminated water (NOT contagious);

think of pipes, cooling towers, hospital with warm water!!

3

Legionella survives ____ by

endocytosis; monocytes and macrophages by altering endosomes (fusion of phagosome and lysosome) so it can multiply in them and then escape

4

What are new environments for legionella?

Cooling towers and whirlpool spas (legionella NOT evolved to live by altering endosomes, so they will die off with the host or by immunity and antibiotics)

5

LD (Legionnaire's Disease) outbreaks trace to

contaminated LOCATIONS (not people); duh: hospitals (nosocomial)

6

LD pneumonia is

life-threatening even when treated with antibiotics (as opposed to asymp seroconversion or Pontiac fever)

7

Optimal diagnosis of legionella by

BOTH urine antigen test (cell wall component excreted and detect LP1 strain; use tagged secondary Ab) and culture of respiratory secretions (fastidious, special media required: Buffered Charcoal Yeast extract with alpha-ketoglutarate)

8

For geriatric _____ in general, take

community-acquired pneumonias; samples for culture/ELISA first, then start treatment with levofloxacin second, and get labs back third;
Pontiac fever usually resolves on its own

9

Outbreaks in health care for legionella

are common; vulnerable individuals exposed to bad plumbing!!

10

C burnetti is a

small coccus to short rod, zoonotic infection from ruminants (NO VECTOR)

11

C burnetti transmitted by

aerosols, grows in alveolar monocytes/macrophages, survives endolysosomal fusion, extremely infectious, long-lived in environ

12

C burnetti causes

pneumonia/hepatitis = Q Fever;
some complications of pregnancy perhaps

13

Diagnose C burnetti by

IHC (ELISA, IF), treat with tetracyclines or fluroquinolones

14

Mycoplasma unique among bacteria in

lacking a cell wall and including cholesterol in their cell membrane

(fried egg appearance)
Fried egg has a lo of cholesterol

15

Mycoplasma causes

"walking" pneumonia: mild and self-limited

(transmission: inhalation of respiratory aerosols)

16

CARDS is

exotoxin-induced ciliostasis (dry cough), local inflamm, local tissue destruction, production of "cold agglutinins" targeting RBC's (risk of anemia)

17

Persistence of mycoplasma through

slow growth and IC hiding

18

Treat mycoplasma

as needed with tetracyclines or macrolides; fluoroquinolones cover mycoplasma
(patient might also be anemic)

19

There are also a few

other mycobacteria that are minor pathogens of the repro and urinary tracts

20

Legionella virulence factors include:

1. Type IV secretion system (alters endosome)
2. Pilus formation (attachment)
3. Zn metalloprotease (escape)

21

Risk factors for LD:

Increasing age, immunosuppression, smoking, chronic heart/lung disease, chronic swallowing disorder, male