5.4 Gram Positive Anaerobic Rods

Question 1

clostridium is widespread in __________ and commensal of the _____________

Answer 1

in the soil; large bowel

Question 2

clostridium multiplies slow/rapid

Answer 2

rapid

Question 3

T/F clostridium is spore-forming

Answer 3

T

Question 4

what is a key virulence factor of clostridium spp.

Answer 4

spore forming and produce powerful toxins

Question 5

what are the 3 types of pathogenic clostridia

Answer 5

enterotoxin; histotoxic; neurotoxic

Question 6

what spp of clostridia are enterotoxic

Answer 6

C. perfringens type A-E; C. difficile

Question 7

what spp. of clostridia are neurotoxic

Answer 7

C. tetani and C. botulinum

Question 8

what spp. of clostridia are histotoxic

Answer 8

C. chauvoei, C. septicum, C. novyi, C. sordelli, C. perfringens type A

Question 9

describe enterotoxic vs neurotoxic vs histotoxic clostridia

Answer 9

enterotoxic: toxins are produced in the intestines, absorbed into the blood and then cause toxemia

histotoxic: gas-gangrene producing, invasive

neurotoxic: non-invasive and colonize the nervous system

Question 10

T/F C. perfringens is zoonotic and reportable

Answer 10

F

Question 11

what is the fastest growing bacterium known

Answer 11

C. perfringens

Question 12

what type of contamination is C. perfringens associated with

Answer 12

fecal contamination

Question 13

how many types of toxins does C. perfringens produce

Answer 13

7 (A-G)

Question 14

what type of C. perfringens is associated with lamb dysentry? what is the toxin?

Answer 14

C. perfringens type B; Beta and epsilon

Question 15

what type of C. perfringens is commensal? what is the toxin?

Answer 15

Type A; alpha

Question 16

describe C. perfringens Type C, E and G; what toxins; what species

Answer 16

Type C: haemorrhagic necrotic enteritis; toxin = beta; all food animals

Type E: haemorrhagic enteritis, toxin = iota; cattle, sheep

Type G: necrotic enteritis; toxin = NetB; poultry

Question 17

what type of C. perfringens is associated with foodborne illness in humans? what is the toxin?

Answer 17

Type F; Cpe

Question 18

what type of C. perfringens is associated with pulpy kidney? what species? what toxin?

Answer 18

Type D; epsilon; sheep and goats

Question 19

what two diseases can be caused by C. perfringens Type A and why does this happen if Type A is usually commensal?

Answer 19

1) abomasitis (calves)
2) haemorrhagic necrotic enteritis (dogs and foals)

Happens when the Type A bacteria produces a toxin other than the alpha toxin

Question 20

what type of C. perfringens is NOT associated with enteritis? what DOES is cause (2)?

Answer 20

pulpy kidney disease (Type D); encephalomalacia and damage to kidneys

Question 21

Type F (Cpe, food poisoning) C. perfringens is associated with ______-rich food consumption by people

Answer 21

protein

Question 22

what type of C. perfringens is both enterotoxic and histotoxic? when histotoxic, what does it cause

Answer 22

Type A; gas gangrene (wound infections) and necrotizing mastitis

Question 23

why is gas gangrene or necrotizing mastitis caused by C. perfringens Type A easy to diagnose

Answer 23

because it should NEVER be isolated anywhere except for the large bowel, where it is normally commensal

Question 24

how do we control C. perfringens (3)

Answer 24

• prophylaxis (broilers)
• vaccination (pulpy kidney)
• hygeine (mastitis/gangrene)

Question 25

how do we treat C. perfringens

Answer 25

debriding (if wound) and antibiotics

Question 26

T/F C. difficile is zoonotic and reportable

Answer 26

F; zoonotic but not reportable

Question 27

what is the main disease caused by C. difficile and in what species

Answer 27

typhlocolitis in horses

Question 28

how does C. difficile develop

Answer 28

antibiotics disrupt the normal flora, but C. diff survives as a spore; C. diff can then proliferate and cause typhlocolitis a few days after starting or terminating antibiotics

Question 29

how is C. difficile transmitted and activated

Answer 29

via spores, which are activated by the stomach and bile acids

Question 30

what toxins does C. difficile produce (2)

Answer 30

Toxin A: enterotoxin and cytotoxin Toxin B: cytotoxin

Question 31

what is a major cause of hospital acquired infections in humans getting antibiotic treatment

Answer 31

C. difficile

Question 32

T/F C. diff can be isolated from meat

Answer 32

T

Question 33

what is an important diagnostic test for C. difficile

Answer 33

glutamate dehydrogenase (GDH) ELISA

Question 34

how do we treat C. difficile

Answer 34

antibiotics, probiotics, fecal transplant

Question 35

what causes blackleg

Answer 35

C. chauveoi

Question 36

what causes pseudoblackleg

Answer 36

C. septicum, C. novyi

Question 37

what is blackleg and when does it commonly occur

Answer 37

acute necrotizing myostitis and systemic toxemia caused by C. chauvoei

Question 38

what type of year is blackleg common and why

Answer 38

in the summer; it is caused by ingestion of spores in the soil

Question 39

what is the pathogenesis of blackleg

Answer 39

ingestion of spores -> spores travel via the blood to the muscles -> anoxia activates the spores -> necrotizing myostitis -> toxemia -> death

Question 40

how do we diagnose blackleg based on signs

Answer 40

swollen legs, gas under skin

Question 41

C. chauvoei is susceptible to ____________ and resistant to ____________

Answer 41

penicillin; aminoglycosides

Question 42

what species cause gas gangrene

Answer 42

C. perfringens Type A; C. chauvoei, C. septicum, C. novyi, C. sordellii

Question 43

gas gangrene mainly affects what species

Answer 43

ruminants and horses

Question 44

what is the treatment for gas gangrene

Answer 44

surgical debridement and antibiotics

Question 45

what is the structure of C. tetani

Answer 45

tennis racket (rod-terminal spores)

Question 46

where is C. tetani found and in what species specifically (what is most susceptible)

Answer 46

intestine and manure; especially horses

Question 47

what species can develop tetanus

Answer 47

ALL

Question 48

what is the pathogenesis of C. tetani

Answer 48

toxin produced at infection site (ex. deep wound) -> travels up axons to CNS -> goes to inhibitory neuron -> inhibits GABA/glycine release -> spastic paralysis

Question 49

how do we treat tetanus

Answer 49

dark, quiet environment, mm relaxants, respirator prevent with vaccination, toxoid

Question 50

what produces the most potent toxin known

Answer 50

C. botulinum

Question 51

how does botulism typically happen

Answer 51

ingestion of the preformed toxin from the environment

Question 52

what is the pathogenesis of botulism

Answer 52

the toxin is usually ingested -> impacts cholinergic presynaptic cells -> inhibits ACh release

Question 53

how do we diagnose butulism

Answer 53

toxin test in mice , PCR