Select Agents - Bioterrism

Question 1

Yersinia pestis
gram - or +
aerobe or anaerobe
virulence factors
transmission

Answer 1

gram - rod
facultative anaerobe
T3SS, YOPS, capsule, siderophores, LPS
Xenopsylla cheopis flea esp in rainy, warm environments

Question 2

Yersinia pestis
host:
reservoir:
clinical signs:

Answer 2

cats, dogs, bears, skunks, raccoons
rodents
bubonic plague, septicemic plague or pneumonic plague

Question 3

which plague caused by Y. pestis is contagious?

Answer 3

pneumonic plague is contagious

Question 4

which plague caused by Y. pestis is more common in cats/dogs? what is the most common sign?

Answer 4

bubonic plague
lymphadenopathy + fever

Question 5

diagnostics for Yersinia pestis

Answer 5

rule out in endemic areas via PCR, aerobic culture or FA

Question 6

treatment and control for Yersinia pestis

Answer 6

doxy, fluoroquinolones, aminoglycosides
flea/tick prevention

Question 7

Francisella tularensis “Tularemia”
gram - or +
aerobe or anaerobe
intracellular?
capnophillic?
transmission

Answer 7

gram - coccobacillus
aerobe, nonfermenter
intracellular
capnophillic
arthropods: ticks (Ambylomma & Dermacentor most common), fleas, mosquitos

Question 8

Francisella tularensis “Tularemia”
host
reservoir
clinical signs

Answer 8

dogs/cats
lagomorphs, rodents, water/soil with infected carcasses
lymphadenopathy, bronchopneumonia, typhoidal hepatomegaly/splenomegaly, oculoglandular conjunctivitis, rabbit fever, lawnmower pneumonia, multifocal hepatic necrosis

Question 9

Francisella tularensis “Tularemia”
pathogenesis

Answer 9

arthropod bits, inhalation, ingestion, direct contact
humans/cats highly infectious
evade immune system by escaping phagolysosomes
replicates in cytosol of macrophages

Question 10

Francisella tularensis “Tularemia” diagnostics

Answer 10

febrile cats + lymphadenopathy
PCR
aerobic culture w/ cysteine & chocolate agar
FA/agglutination
post-mortem

Question 11

Francisella tularensis “Tularemia” treatment and control

Answer 11

doxy, fluoroquinolones (enrofloxacin)
limits wildlife exposure
PPE

Question 12

Bacillus antracis
gram - or +
aerobe or anaerobe
spore or nonspore forming

Answer 12

gram + large rod
facultative anaerobe
spore-forming

Question 13

B. antracis
virulence factors
transmission
risk factors

Answer 13

exotoxins:
lethal toxin (pXO1)
edema toxin (pXO1)
protective antigen (pXO1)
capsule (pXO2)

wounds, ingestion, arthropods, inhalation

alkaline, Ca, N rich soil, flooding/drought cycles, history in area

Question 14

B. antracis pathogenesis
infectious stage
tropism

Answer 14

spores (infectious stage)
tropism for mononuclear cells
escape phagolysosome
rapid expansion in blood/tissue
systemic spread
vascular permeability/necrosis

Question 15

B. antracis
host
reservoir
clinical signs

Answer 15

ruminants, horses, pigs, dogs, humans
soil, infected animals
ruminants: lack of rigor mortis, lack of blood clotting, blood pooling from orifices
horses, pigs, humans: intestinal dz
dogs: oropharyngeal anthrax/edema
humans: pulmonary anthrax - woolsorter’s disease & malignant carbuncle (cutaneous dz)

Question 16

B. antracis diagnostics

what are some culture characteristics?

Answer 16

PCR preferred
aerobic culture - medusa head, ground glass, non-hemolytic
identification via pCR or bacteriophage gamma susceptibility
polychrome methylene blue stain on blood smear to see chains of boxcars with pink capsule

Question 17

B. antracis treatment and prevention

Answer 17

abx early - penicillin, tetracyclines
vx in endemic areas during high risk conditions with live strain or sterne strain that lacks XO2 encoding capsule