Flashcards in Legionella Deck (19)
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
Contaminated aerosols dapat
Which is false about Legionella?
A. Oxidase (-)
B. Catalase (+)
Specialized media for Legionella
Buffered Charcoal Yeast Extract agar
In lab diagnosis of Legionella, seroconversion must be seen. What is seroconversion?
4 fold or greater rise in specific serum antibody titer L. pneumophila
Where was Legionnaire's disease first discovered?
American Legion Convention.
How is L.pneumophila transmitted?
Contaminated aerosol droplets
To create biofilms, what does L.pneumophila secrete?
Identify the clinical manifestation:
- Incubation period: 1-2 days
- flu-like; fever, headache, malaise
- milder than Legionnaire’s (no mortality)
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
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
60 degrees dapat
In staining Legionella, what must be used instead of safranin?
Basic fuchsin (0.1%)
Does person to person transmission of Legionella occur?
True about Legionella
A. Produces gelatinase
B. Does not hydrolyze hippurate
C. Does not produce beta-lactamase
Major outer membrane protein inhibits __
Acidifiation of phagolysosome
Macrophage infectivity/invasion potentiator is required for ___
Optimal internalization, determines cell entry
What is coiling phagocytosis?
Bacteria replicates inside vacuole, recruits RER & prevents phagolysosome fusion
Legionella grow slowly, yes or no?
Esp in blood culture: at least 2 wks
When are serologic tests most useful in detecting Legionella?
Retrospective diagnosis @ outbreaks