Zoonotic Bacteria (Yersinia, Brucellosis, Tularensis, Borrelia)

Question 1

Francisella tularensis: Gram stain? capsular? location?

Answer 1

Gram negative; capsule; facultatively intracellular (in macrophages)

Question 2

special feature of culturing F. tularensis

Answer 2

extremely infective! (low ID50) => special training required to culture it

Question 3

natural habitat of F. tularensis

Answer 3

rabbits, ticks, small wild animals, deer flies

Question 4

transmission of F. tularensis

Answer 4

bites, contact with secretions/mucosa, inhaled aerosols of blood (ie skinning animals, tick popping), ingesting contaminated meat or water

Question 5

4 manifestations of F. tularensis

Answer 5

1) Tularemia (Rabbit Fever)
2) Oculoglandular
3) Ulceroglandular
4) Other (sepsis, pneumonia, GI: depends on route of access)

Question 6

Oculoglandular form (F. tularensis)

Answer 6

Innoculated at eye, leads to a painful conjunctivitis with an ulcer, small yellow bumps, regional lymphadenopathy

Question 7

Ulceroglandular form (F. tularensis)

Answer 7

Skin ulcers form at infection site, fever

Question 8

Tularemia

Answer 8

3-5 day incubation, abrupt onset fever, malaise, rigors, fatigue; 30% mortality rate

Question 9

Brucella: Gram? aerobicity? location? capsule?

Answer 9

Gram negative, aerobic, intracellular (in macrophages), no capsule

Question 10

habitat of Brucella

Answer 10

cattle, sheep, goat, dog

Question 11

transmission of Brucella

Answer 11

contact with hosts (vets/farmers/slaughterhouse workers), unpasteurized dairy, airborne inhalation

Question 12

pathogenesis of Brucella

Answer 12

gets into macrophages, resists lysosyme fusion;
spreads to spleen, liver, LNs, bone marrow;
kills cell upon exiting;
prompts Th1, B cell response & granuloma at site

Question 13

Brucellosis S/S

Answer 13

• undulating fever
• reactive arthritis (usually small joints)
• weight loss, malaise, rigor, night sweats, fatigue