E2 Anaerobes

Question 1

Where do anaerobes like to live?

Answer 1

Intestinal tract

Commensals!

Question 2

What is common pathogenic factor among anaerobes?

Answer 2

Toxins!

Question 3

What are the two classes of anaerobes?

Answer 3

1. Obligate = die in O2

2. Aerotolerant = kinda like facultative bacteria but use fermentation

Question 4

Why do obligate anaerobes die when exposed to O2?

Answer 4

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

Question 5

What are signs of an anaerobic infection (4)?

Answer 5

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

Question 6

What are some anaerobic environments in healthy animals?

Answer 6

1. Oral cavity between teeth and gums

2. Intestines

Question 7

How can anaerobic grow in wounds?

Answer 7

Facultative bacteria use up all the O2 first

Question 8

What is Eh?

Answer 8

Measure of redox potential

Lower Eh = more anaerobic environment

Question 9

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

Answer 9

Clostridium!

Question 10

What are the two groups of Clostridium?

Answer 10

1. Tissue invasive w/ weak toxins

2. Non-invasive w/ severe toxins

Question 11

Where do Clostridium live in nature?

Answer 11

Soil!

Can also be normal commensals

Question 12

What is type A Clostridium?

Answer 12

Has only alpha toxin

Normally present in intestines of healthy animals

Question 13

What type of toxins do Clostridia have?

Answer 13

Exotoxins

= secreted toxins

Question 14

What is the most dangerous toxin?

Answer 14

Alpha toxin

Question 15

What type of diseases are caused by Type A Clostridium?

Answer 15

Necrotizing myositis in horses
Gas gangrene
Yellow lamb disease = enterotoxemia

Question 16

What toxin is in Type D clostridium?

Answer 16

Alpha & Epsilon toxins

Question 17

What are some disease caused by Type D clostridium?

Answer 17

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

Question 18

What is Clostridium chauvoei?

Answer 18

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

Question 19

What is special about Clostridium chauvoei’s pathogenesis?

Answer 19

Can remain latent until tissue is damaged!

Question 20

What is Clostridium septicum?

Answer 20

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

Question 21

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

Answer 21

C. septicum does NOT produce gas!

Question 22

What is Clostridium difficile?

Answer 22

Pseudomembranous enterocolitis

Question 23

What can cause Clostridium difficile infections?

Answer 23

Antibiotics

Question 24

What are the clinical signs of Clostridium difficile infection?

Answer 24

Bloody diarrhea

Question 25

How is Clostridium difficile diagnosed?

Answer 25

PCR of feces

Question 26

What are the 2 non-invasive super toxic Clostridia?

Answer 26

1. C. botulinum | 2. C. tetani

Question 27

What is Clostridium tetani?

Answer 27

Causes Tetanus or "Lockjaw"

Question 28

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

Answer 28

``` Most = Horses & Humans Least = Cats, Chickens ```

Question 29

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

Answer 29

Tetanospasmin | Blocks inhibitory NTs at NMJs

Question 30

How do animals become infected with Clostridium tetani?

Answer 30

Spores enter damaged tissue

Question 31

Why is the toxin so lethal?

Answer 31

Binding is permanent | Need to wait for protein turnover

Question 32

What species experience ascending tetanus?

Answer 32

Dogs & cats | = via nerves

Question 33

What species experience descending tetanus?

Answer 33

Horses & Humans | = via blood stream

Question 34

What are clinical signs of Clostridium tetani infection?

Answer 34

1. Stiffness 2. Third eyelid 3. Bloat

Question 35

What do Clostridium tetani look like microscopically?

Answer 35

Drumsticks

Question 36

What is used for the Clostridium tetani vaccine?

Answer 36

Toxoid

Question 37

What is special about Clostridium botulinum?

Answer 37

Forms the most potent toxin known

Question 38

What is common route of Clostridium botulinum poisoning?

Answer 38

Contaminated food

Question 39

What kind of paralysis is produced by Clostridium botulinum?

Answer 39

Flaccid paralysis | C. tetani = spastic paralysis

Question 40

What is Clostridium botulinum toxicity in birds called?

Answer 40

"Limberneck"

Question 41

How is Clostridium botulinum infection diagnosed?

Answer 41

Detection of toxin

Question 42

How is Clostridium botulinum toxicity treated?

Answer 42

Anti-toxin!

Question 43

What are some Gram NEGATIVE anaerobic rods?

Answer 43

1. Bacteroides | 2. Fusobacterium

Question 44

What is Dichelobacter nodosus?

Answer 44

Obligate parasite of hooves "Contagious foot rot" in sheep Secondary invader! after Fusobacterium FOUL smelling

Question 45

What is the virulence factor for Dichelobacter nodosus?

Answer 45

Keratin degrading proteases

Question 46

What is Fusobacterium necrophorum?

Answer 46

Calf diphtheria Food rot in cattle = "Scald" Swine = "Bullnose"

Question 47

What is Prevotella melaninogenicus?

Answer 47

Causes suppurative lesions | Implicated in periodontal disease