E2 Anaerobes Flashcards Preview

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Flashcards in E2 Anaerobes Deck (47)
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1

Where do anaerobes like to live?

Intestinal tract
Commensals!

2

What is common pathogenic factor among anaerobes?

Toxins!

3

What are the two classes of anaerobes?

1. Obligate = die in O2
2. Aerotolerant = kinda like facultative bacteria but use fermentation

4

Why do obligate anaerobes die when exposed to O2?

H202 and superoxide are formed
= toxic
= lack enzymes to deal with these chemicals

5

What are signs of an anaerobic infection (4)?

1. Painful tissue necrosis
2. Gas in the wound
3. Foul odor
4. Black discoloration

6

What are some anaerobic environments in healthy animals?

1. Oral cavity between teeth and gums
2. Intestines

7

How can anaerobic grow in wounds?

Facultative bacteria use up all the O2 first

8

What is Eh?

Measure of redox potential
Lower Eh = more anaerobic environment

9

What is a spore forming Gram POSITIVE bacteria that are anaerobic?

Clostridium!

10

What are the two groups of Clostridium?

1. Tissue invasive w/ weak toxins
2. Non-invasive w/ severe toxins

11

Where do Clostridium live in nature?

Soil!
Can also be normal commensals

12

What is type A Clostridium?

Has only alpha toxin
Normally present in intestines of healthy animals

13

What type of toxins do Clostridia have?

Exotoxins
= secreted toxins

14

What is the most dangerous toxin?

Alpha toxin

15

What type of diseases are caused by Type A Clostridium?

Necrotizing myositis in horses
Gas gangrene
Yellow lamb disease = enterotoxemia

16

What toxin is in Type D clostridium?

Alpha & Epsilon toxins

17

What are some disease caused by Type D clostridium?

Enterotoxemia of sheep & goats
"Pulpy kidney disease"
"Overeating disease"
= Epsilon toxin!

18

What is Clostridium chauvoei?

Black leg in ruminants
1. Wounds
2. Inhalation
3. Tooth loss
= necrotic muscle tissue

19

What is special about Clostridium chauvoei's pathogenesis?

Can remain latent until tissue is damaged!

20

What is Clostridium septicum?

Malignant edema
Ingestion of spores
Rapid death! 1-2 hrs

21

How is Clostridium septicum different from Clostridium chauvoei (Blackleg)?

C. septicum does NOT produce gas!

22

What is Clostridium difficile?

Pseudomembranous enterocolitis

23

What can cause Clostridium difficile infections?

Antibiotics

24

What are the clinical signs of Clostridium difficile infection?

Bloody diarrhea

25

How is Clostridium difficile diagnosed?

PCR of feces

26

What are the 2 non-invasive super toxic Clostridia?

1. C. botulinum
2. C. tetani

27

What is Clostridium tetani?

Causes Tetanus or "Lockjaw"

28

What species are most susceptible to Clostridium tetani? Least susceptible?

Most = Horses & Humans
Least = Cats, Chickens

29

Of the 3 Clostridium tetani toxins which one is the most pathogenic? What does it do?

Tetanospasmin
Blocks inhibitory NTs at NMJs

30

How do animals become infected with Clostridium tetani?

Spores enter damaged tissue