Sketchy Micro: Legionella

Question 1

What kind of bacteria is Legionella?

Answer 1

Gram-negative rod, but because it doesn’t take up Gram staining well, a silver stain is usually used

(Think of the RED ship joining the LEGION that needs to be painted SILVER.)

Question 2

Legionella requires a freakishly specific medium to culture: _________________.

Answer 2

charcoal-yeast extract with iron and cysteine

(Think of the piles of CHARCOAL on the deck of the ship with the IRON anchor hanging off the side near the ship’s name: the S.S. CYSTEINE.)

Question 3

What is the milder illness caused by Legionella?

Answer 3

Pontiac fever (self-limited malaise)

Think of the overheated Pontiac by the dock.

Question 4

What are clinical signs of the more serious form of Legionella infection?

Answer 4

Legionnaire’s disease is more common in smokers and presents with (1) unilobar pneumonia, (2) hyponatremia, (3) confusion, (4) diarrhea, and (5) fever

(Think of [1] the smoker looking at the blueprint with one section of the ship shaded in; [2] the sailor spilling the cart of salt into the marina; [3] the sailor hit on the head with the falling can of silver paint; [4] the sailor mopping the poop deck with muddy pants; and [5] the heat emerging from the coal oven.)

Question 5

What is a good test for confirming the diagnosis of Legionnaire’s disease?

Answer 5

The urine antigen test, which is faster than culturing

Think of the sailor peeing into the water.

Question 6

Legionella is _________-positive.

Answer 6

oxidase (like the ring on the finger of the girl sitting on the bridge to the ship)

Question 7

What antibiotics can treat Legionella?

Answer 7

Macrolides (represented by the crows on the cranes above the Pontiac) and fluoroquinolones (represented by the flower being given to the oxidase girl)