Bacterial zoonoses I Flashcards Preview

Year 1 Microbiology > Bacterial zoonoses I > Flashcards

Flashcards in Bacterial zoonoses I Deck (48):
1

What is the gram stain for bacillus anthracis?

Gram positive

2

What is the shape of bacillus anthracis?

Rod

3

Is bacillus anthracis aerobic or anaerobic?

Aerobic

4

Does bacillus anthracis form spore?

Yes

5

What is the appearance of bacillus anthracis in culture?

Long chains / pairs / single cells with "boxcar" ends

6

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

Probably not

7

What is the main virulence factor for bacillus anthracis?

Protein capsule made of poly-D-glutamate

8

What are the two toxins produced by bacillus anthracis?

Lethal toxin and edema toxin

9

What is the role of lethal toxin?

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

10

What is the role of edema toxin?

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

11

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

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

12

What is the pathogenesis of bacillus anthracis?

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

13

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

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

14

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

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

15

What is the treatment for cutaneous anthrax?

Amoxicillin

16

What is the treatment for inhalation anthrax?

Doxycycline, ciprofloxacin + 2 other Abx

17

What is the gram stain for brucella?

Gram negative

18

What is the shape of brucella?

Coccobacillus

19

What is the pathogenesis of brucella?

Intracellular pathogens - survive within phagosomes of macrophages and monocytes

20

What is the transmission for brucellosis?

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

21

What is the presentation for brucellosis?

Acute undulating fever, joint pain, headache, drenching sweats

22

What is the treatment for brucellosis?

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

23

What is the gram stain for pasteurella multocida?

Gram negative

24

What is the shape of pasteurella multocida?

Coccobacillus

25

What are the virulence factors for pasteurella multocida?

LPS and polysacccharide capsule (hyaluronic acid)

26

In the US, how do pasteurellosis infections usually occur?

Following scratch or bite of a cat or dog

27

What is the treatment for pasteurellosis?

Penicillin

28

What is the gram stain for leptospira?

Gram negative (weakly)

29

What is the shape of leptospira?

Spiral shaped with terminal hooks

30

How is leptospira best visualized?

Darkfield

31

What is the pathogenesis of leptospirosis?

Infects via cuts and mucous membrane exposure from contaminated water

32

What are the two phases of leptospirosis?

1. Febrile, influenza-like 2. Disseminated

33

What is the treatment for leptospirosis?

Penicillin and ampicillin

34

What is the gram stain for francisella tularensis?

Gram negative

35

What is the shape of francisella tularensis?

Coccobacillus

36

What is the pathogenesis of francisell tularensis?

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

37

What is crucial for resolution of tularemia infection?

CMI (macrophage activation)

38

What are the virulence factors for francisella tularensis?

Intracellular pathogen, polysaccharide capsule (strongest), LPS

39

What is the vector for francisella tularensis?

Hard-shell ticks

40

What are the three major forms of tularemia?

Skin, eye, lungs

41

Patients with ulceroglandular tularemia will present with which symptoms?

Red, swollen, painful, ulcerative papule and photophobia

42

What is the treatment for tularemia?

Gentamicin

43

What is the gram stain for yersinia pestis?

Gram negative

44

What is the shape of yersinia pestis?

Rod with bipolar Giemsa staining ("safety pin")

45

What stain is used for yersinia pestis?

Giemsa

46

What are the yersinia pestis virulence factors?

Protein capsule, LPS, three plasmids

47

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

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

48

What is the treatment for bubonic plague?

Streptomycin