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Flashcards in (SOME) Zoonoses Deck (105)
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1

Describe the physical structure of Bacillus.

G+ Rods
Large, Fat, Square Ends
Chains, Palisades, Clumps

2

Bacillus response to adversity?

Sporulation

3

Oxygen metabolism of Bacillus.

Aerobic
Some species have butanediol or lactate ferm pathways.

4

Where can Bacillus be found primarily?

Soil and on Leaf Surfaces

5

Two types of Bacillus we covered?

Bacillus cereus
Bacillus anthracis

6

Bacillus cereus is typically seen in what context?

Food Poisoning

7

Describe the physical appearance of Bacillus cereus spores.

Subterminal

8

Describe the physical appearance of Bacillus cereus colonies on agar plates.

Large, flat, rough

9

What two varieties of Bacillus cereus are seen clinically?

Emetic Variety
Diarrheal Variety

10

Describe the clinical presentation of emetic variety Bacillus cereus.

Very Acute Onset (1-6 hrs)
Recovery in 12 hours
Nausea, Vomiting, Cramps

11

Describe the clinical presentation of the diarrheal variety of Bacillus cereus.

Slow onset (8-16 hrs)
Profuse Diarrhea, Cramps
No Vomiting

12

How do people get Bacillus cereus?

Cooked rice and pasta that has been cooled too slowly?

13

Why the fuck does it matter how slowly my rice cools?

Cooling slowly allows spores to germinate and produce the toxin

14

How many toxins are associated with Bacillus cereus?

4 (1 emetic toxin and three enterotoxins)

15

What does the emetic toxin of Bacillus cereus do?

K+ Ionophore

16

What are the three enterotoxins associated with Bacillus cereus?

Hemolytic
Non-hemolytic (pore-formers)
Cytotoxin (Activates Ad cyclase)

17

Unique physical characteristics of Bacillus anthracis?

Central Spores
"Cut glass" colonies on blood agar
Poly-D-glutamate capsule

18

Clinical presentation of Bacillus anthracis?

Papule (12-36 hrs) becomes a large necrotic eschar
Disseminates and becomes systemic
May infect any organ

19

What is an eschar?

a dry, dark scab or falling away of dead skin

20

Three most common causes of diarrhea (not necessarily in order)

Norovirus
S Aureus
B cereus

21

How is Bacillus anthracis typically contracted?

- Animals ingest/carry spores from soil
- Human handles infected animal materials
- Spore contacts mucous membranes or enter through abrasions
- Germinate in Macrophages after engulfment

22

How long are Bacillus anthracis spores viable?

more than 50 years

23

Four ways (even though they may kind of overlap..) that Bacillus anthracis can get into the body

Contact Mucus Membrane
Abrasion
Inhalation
Ingestion

24

Why should we give a shit about Bacillus anthracis if it comes up less than once a year in the whole world?

Possibly comes up in bioweaponization

25

What do spores do upon entering the host?

Enter macrophages
Germinate in the phagolysosome (upon O2 radical exposure)

26

Can Bacillus anthracis spores be found in blood smears?

No

27

Describe the Bacillus anthracis toxin

Tripartite AB-type (A2B) toxin

28

What are the three components of Bacillus anthracis toxin?

Binding (Protective Antigen)
Lethal Factor
Edema Factor

29

What does Bacillus anthracis Lethal Factor do?

It is a MAP Kinase Protease responsible for necrosis

30

What does Bacillus anthracis Edema factor do?

It is a calmodulin-dependent adenyl cyclase
It makes cAMP, which causes H2O secretion into tissues