Legionella Flashcards Preview

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Flashcards in Legionella Deck (19):
0

False about Legionella
A.stains poorly with gram stain B.Facultative intracellular pathogen
C.Grows best in warm water sources D.Transmitted via person to person contact

D

Contaminated aerosols dapat

1

Which is false about Legionella?
A. Oxidase (-)
B. Catalase (+)
C. Motile

A

2

Specialized media for Legionella

Buffered Charcoal Yeast Extract agar

3

In lab diagnosis of Legionella, seroconversion must be seen. What is seroconversion?

4 fold or greater rise in specific serum antibody titer L. pneumophila

4

Where was Legionnaire's disease first discovered?

American Legion Convention.

5

How is L.pneumophila transmitted?

Contaminated aerosol droplets

6

To create biofilms, what does L.pneumophila secrete?

Alginate

7

Identify the clinical manifestation:
- Incubation period: 1-2 days
- flu-like; fever, headache, malaise
- milder than Legionnaire’s (no mortality)
- self-limiting

Pontiac fever

8

Sequence the Steps in pathogenesis:
A.Lysis of the phagosome leads to apoptosis and release of the organism B.Phagocytosis into the monocytes by binding to complement receptors
C.Replication within the phagosome
D.Inhibition of phagolysosome fusion (phagosome+lysosome)

B D C A

9

Which is not an effective prevention measure for Legionella?
A,Regularly maintain and clean cooling towers and evaporative condensers
B.Maintain domestic water heaters at 40°C
C. Avoid conditions that allow water to stagnate.
D. Frequent flushing of unused water lines

B.
60 degrees dapat

10

In staining Legionella, what must be used instead of safranin?

Basic fuchsin (0.1%)

11

Does person to person transmission of Legionella occur?

No

12

True about Legionella
A. Produces gelatinase
B. Does not hydrolyze hippurate
C. Does not produce beta-lactamase

A

13

Major outer membrane protein inhibits __

Acidifiation of phagolysosome

14

Macrophage infectivity/invasion potentiator is required for ___

Optimal internalization, determines cell entry

15

What is coiling phagocytosis?

Bacteria replicates inside vacuole, recruits RER & prevents phagolysosome fusion

16

Legionella grow slowly, yes or no?

Yes
Esp in blood culture: at least 2 wks

17

When are serologic tests most useful in detecting Legionella?

Retrospective diagnosis @ outbreaks

18

False about L.micdadei
A.acid-fast in tissues
B.able to hydrolyze hippurate
C.absence of beta-lactamase
D.pneumonia causing usually in immunocompromised

B