Legionella

Question 1

Legionella pneumophilia is a gram _____ _____

Answer 1

Gram negative bacilli

Question 2

What virulence factor of L. pneumophilia induces a macrophage to take it up by coiling phagocytosis?

Answer 2

Mip (Macrophage infectivity promoter)

Question 3

What two virulence factors of L. pneumophilia disturb acidification of the phagosome, prevent lysosomal fusion and take over organelle trafficking to provide nutrients, ultimately making a nice home for the organism out of a phagosome?

Answer 3

• Icm (intracellular multiplication
• Dot (defect in organelle trafficking)

Question 4

L. pneumophilia produces _____ to help it spread through tissues.

Answer 4

Metalloproteases

Question 5

L. pneumophilia produce _____ and _____ to help it get out of the phagosome when ready

Answer 5

Hemolysins and phospholipases

Question 6

L. pneumophilia is ubiquitous in what kind of environments?

Answer 6

Fresh water

Question 7

L. pneumophilia is notorious for living in what household appliance?

Answer 7

Air conditioning cooling towers

Question 8

How is L. pneumophilia acquired?

Answer 8

Via aerosolization and subsequent inhalation

Question 9

Legionella, once inhaled, is covered in C3b then, enter macrophages through _____ or _____ phagocytosis

Answer 9

• Coiling phagocytosis
  
  • via CR1 & CR3
• Conventional phagocytosis
  
  • via Fc

Question 10

What two groups are at risk for L. pneumophilia infection?

Answer 10

• Pts. with decreased cellular imunity
• Pts. with compromised pulmonary function

Question 11

The initial symptoms of Legionnaire’s disease that occur

2-10 days after exposure are _____. They can progress to a _____ pneumonia.

Answer 11

• Flu like
  
  • Fever, chills, headache, nonproductive cough
• Can progress to a necrotizing pneumonia

Question 12

The necrotizing pneumonia of advanced Legionnaire’s disease deomonstrates _____ consolidation, _____, and a “_____” appearance

Answer 12

• Multilobar consolidation
• Microabscesses
• “Moth eaten” appearance on xray

Question 13

_____ is a milder form of Legionnaires that presents with similar flu-like symptoms, but WITHOUT _____

Answer 13

Pontiac Fever presents similarly to Legionnaire’s, but WITHOUT PNEUMONIA

Question 14

T/F Pontiac Fever requires antibiotics

Answer 14

FALSE

There is a spontaneous cure about 2-5 days after illness

Question 15

Antigen for the L. pneumophilia serogroup 1 can be found in _____

Answer 15

Urine

Question 16

What kind of medium does L. pneumophilia grow on?

Answer 16

BCYE (Buffered charcoal yeast extract)

Look how pretty:

Question 17

Assessing the _____ for presence of L. pneumophilia is not a good option.

Answer 17

• Sputum
  
  • No productive cough
  • Check bronchial lavage, lung biopsy, blood (if septic), pleural fluid (if effusion present)

Question 18

What stains are used to diagnose L. pneumophilia infetion?

Answer 18

• Silver stain
• Immunofluorescence stain

Question 19

What treatment options are available for Legionnaire’s Disease?

Answer 19

• Macrolides
  
  • Azithromycin
  • Clarithromycin
• Fluoroquinolones