Sketchy Micro: Francisella Tularensis

Question 1

The main reservoir for Francisella tularensis is ____________.

Answer 1

rabbits (like the rabbit-centered Sketch)

Question 2

Humans usually get F. tularensis by ____________.

Answer 2

getting bitten by a dermacentor tick that has just bitten a rabbit infected with Francisella

(Think of the rabbit scratching ticks off.)

Question 3

Why is tularemia a reportable illness (to the CDC)?

Answer 3

Because Francisella has been shown to be able to be aerosolized, so it could be used as a bioweapon.

Question 4

What kind of bacteria is Francisella?

Answer 4

• Gram-negative coccobacillus (like the ovoid radishes in the garden)
• Facultative intracellular (like the open cage next to the rabbit)

Question 5

What is the usual progression of Francisella infection?

Answer 5

It causes an infection at the site of the tick bite (represented by the rabbit hole) and then spreads via macrophages to the lymphatics where it creates caseating granulomas (like the rotten patch of radishes hidden in the rabbit hole).

Question 6

The classic physical exam finding of tularemia is _____________.

Answer 6

regional lymphadenopathy (like the mounds of dirt pushed up by the radish stores)

Question 7

What drug treats Francisella?

Answer 7

Streptomycin, an aminoglycoside (like the sai stuck into the ground)