Bacterial zoonoses I

Question 1

What is the gram stain for bacillus anthracis?

Answer 1

Gram positive

Question 2

What is the shape of bacillus anthracis?

Answer 2

Rod

Question 3

Is bacillus anthracis aerobic or anaerobic?

Answer 3

Aerobic

Question 4

Does bacillus anthracis form spore?

Answer 4

Yes

Question 5

What is the appearance of bacillus anthracis in culture?

Answer 5

Long chains / pairs / single cells with “boxcar” ends

Question 6

If you collect a sample from a patient with bacillus anthracis, will you see spores?

Answer 6

Probably not

Question 7

What is the main virulence factor for bacillus anthracis?

Answer 7

Protein capsule made of poly-D-glutamate

Question 8

What are the two toxins produced by bacillus anthracis?

Answer 8

Lethal toxin and edema toxin

Question 9

What is the role of lethal toxin?

Answer 9

Disrupts normal cellular signaling events leading to cell death, inflammation, and tissue damage

Question 10

What is the role of edema toxin?

Answer 10

Activates adenylate cyclase, leading to increased cAMP levels, ion/water efflux, and edema

Question 11

What is the role of protective antigen in bacillus anthracis infection?

Answer 11

1. Acts like the B subunit of an A-B toxin; binds lethal and edema factors to form toxins then facilitates internalization of toxins 2. Binds to each factor to form the toxins

Question 12

What is the pathogenesis of bacillus anthracis?

Answer 12

1. Spores are inoculated, ingested, or inhaled 2. Spores germinate into vegetative cells that produce toxin

Question 13

What are the features of a lesion caused by cutaneous anthrax?

Answer 13

Small red painless papule that evolves into an vesicle then a necrotic ulcer with black center (eschar)

Question 14

What are the symptoms of (second stage) inhalation anthrax?

Answer 14

Fever, drenching sweats, extreme dyspnea, cyanosis, lymphadenopathy, shock, death

Question 15

What is the treatment for cutaneous anthrax?

Answer 15

Amoxicillin

Question 16

What is the treatment for inhalation anthrax?

Answer 16

Doxycycline, ciprofloxacin + 2 other Abx

Question 17

What is the gram stain for brucella?

Answer 17

Gram negative

Question 18

What is the shape of brucella?

Answer 18

Coccobacillus

Question 19

What is the pathogenesis of brucella?

Answer 19

Intracellular pathogens - survive within phagosomes of macrophages and monocytes

Question 20

What is the transmission for brucellosis?

Answer 20

Aerosol or ingestion - contaminated food (unpasteurized milk), direct contamination with infected animal

Question 21

What is the presentation for brucellosis?

Answer 21

Acute undulating fever, joint pain, headache, drenching sweats

Question 22

What is the treatment for brucellosis?

Answer 22

6 week or longer course of a tetracycline (doxycycline) + rifampin

Question 23

What is the gram stain for pasteurella multocida?

Answer 23

Gram negative

Question 24

What is the shape of pasteurella multocida?

Answer 24

Coccobacillus

Question 25

What are the virulence factors for pasteurella multocida?

Answer 25

LPS and polysacccharide capsule (hyaluronic acid)

Question 26

In the US, how do pasteurellosis infections usually occur?

Answer 26

Following scratch or bite of a cat or dog

Question 27

What is the treatment for pasteurellosis?

Answer 27

Penicillin

Question 28

What is the gram stain for leptospira?

Answer 28

Gram negative (weakly)

Question 29

What is the shape of leptospira?

Answer 29

Spiral shaped with terminal hooks

Question 30

How is leptospira best visualized?

Answer 30

Darkfield

Question 31

What is the pathogenesis of leptospirosis?

Answer 31

Infects via cuts and mucous membrane exposure from contaminated water

Question 32

What are the two phases of leptospirosis?

Answer 32

1. Febrile, influenza-like 2. Disseminated

Question 33

What is the treatment for leptospirosis?

Answer 33

Penicillin and ampicillin

Question 34

What is the gram stain for francisella tularensis?

Answer 34

Gram negative

Question 35

What is the shape of francisella tularensis?

Answer 35

Coccobacillus

Question 36

What is the pathogenesis of francisell tularensis?

Answer 36

Intracellular pathogen of monocytes and macrophages - prevents phagolysosome fusion and acidification

Question 37

What is crucial for resolution of tularemia infection?

Answer 37

CMI (macrophage activation)

Question 38

What are the virulence factors for francisella tularensis?

Answer 38

Intracellular pathogen, polysaccharide capsule (strongest), LPS

Question 39

What is the vector for francisella tularensis?

Answer 39

Hard-shell ticks

Question 40

What are the three major forms of tularemia?

Answer 40

Skin, eye, lungs

Question 41

Patients with ulceroglandular tularemia will present with which symptoms?

Answer 41

Red, swollen, painful, ulcerative papule and photophobia

Question 42

What is the treatment for tularemia?

Answer 42

Gentamicin

Question 43

What is the gram stain for yersinia pestis?

Answer 43

Gram negative

Question 44

What is the shape of yersinia pestis?

Answer 44

Rod with bipolar Giemsa staining ("safety pin")

Question 45

What stain is used for yersinia pestis?

Answer 45

Giemsa

Question 46

What are the yersinia pestis virulence factors?

Answer 46

Protein capsule, LPS, three plasmids

Question 47

The plasmids associated with yersinia pestis virulence carry what three major genes?

Answer 47

Biofilm formation, enhanced resistance to macrophage killing, resistance to complement mediated lysis

Question 48

What is the treatment for bubonic plague?

Answer 48

Streptomycin