Clostridia I & II

Question 0

Clostridia are: GM (+/-) ______

Answer 0

GM + rods

Question 1

Clostridia are: obligate/facultative aerobes/anaerobes

Answer 1

Obligate Anaerobes

Question 2

T/F: Clostridia form spores

Answer 2

True

Question 3

Clostridia are: catalase (neg/pos)

Answer 3

Catalase Negative

Question 4

Clostridia are: Oxidase (pos/neg)

Answer 4

Oxidase negative

Question 5

Which clostridia species is highly invasive and causes gas gangrene?

Answer 5

Clostridium perfringens

Question 6

Which clostridium species is generally non invasive and secretes a toxin that causes pseudommembranous enterocolitis?

Answer 6

Clostridium difficle

Question 7

Which clostridium species is generally noninvasive and is the causeitive agent of tetanus?

Answer 7

Clostridium tetani

Question 8

which clostridium is non invasive and causes botulism

Answer 8

C. botulinum

Question 9

Which clostridia toxin causes flaccid paralysis?

Answer 9

botulism toxin

Question 10

which clostridia toxin causes pseudomembranous colitis?

Answer 10

Exotoxin A & B

Question 11

this clostridia species is the only one to form terminal spores - “tennis rackets”

Answer 11

C. Tetai

Question 12

C. Tetani has ____ serological type(s)

Answer 12

ONE

Question 13

The Tetanus toxin is a ______-toxin that is transported to ________

Answer 13

Neurotoxin, transported from infection site to peripheral and CNS nerves (anterior horn cells of S.C. + brain stem)

Question 14

Tetanus toxin mechanism of action:

Answer 14

inhibits glycine and GABA neurotransmitter release => spastic paralysis + convulsive contractions - lockjaw

Question 15

The tetanus toxin has A and B subunits: one binds ______ _______ and the other _________________

Answer 15

binds neuronal ganglioside, the other has neurotoxin activity

Question 16

C. Tetanus infection clinical syndrome:

1. Fever?
2. Spasm?
3. Sensory?
4. Complications?

Answer 16

1. NO FEVER
2. VIOLENT MUSCLE SPASMS
3. NO SENSORY LOSS
4. Involvement of respiratory muscles -> failure -> aspiration, dysphagia, pulmonary infections.

Question 17

C. Tetanus diagnosis made based on:

Answer 17

Clinical syndrome is the best way to diagnose.

Culture only positive in 39% cases. Organism not usually found in wound.

Question 18

Patient has violent flexor muscle spasms, clenched teeth and jaw, no fever, and no sensory loss. They stepped on a soil-y nail a few days ago. The best treatment is:

Answer 18

1. Human tetanus immunoglobulin
2. Penicillin + wound debridement
3. Resp. support
4. Immunization!

Question 19

Tetanus fatality rate:
a - 40 %
b - 50 %
c - 60%
d - 70 %

Answer 19

C - 60% fatality due to pulmonary complications

Question 20

Tetanus immunization accomplished with ____ doses of _____ during the first _______ months/years of life. (Given with the DPT vaccine)

Answer 20

3 doses of toxoid (toxin inactivated by formaldehyde) within the first 6 months of life

Question 21

T/F: Tetanus immunization requires a booster every 5 years

Answer 21

FALSE. Booster required every 10 years. Also, a booster is often given at 1 year and before entering school.

Question 22

T/F: C. Botulinum spores are heat resistant

Answer 22

True

Question 23

T/F: C. Botulinum toxin is heat resistant

Answer 23

False. Botulism toxin is HEAT LABILE

Question 24

C. Botulinum spores are often found in:

Answer 24

Canned food (anaerobic conditions). Spore grow +germinate, form toxin in 2-3 days

Question 25

T/F: botulism toxin is NOT destroyed by stomach acid

Answer 25

True, the toxin is not destroyed by stomach acid, but is heat labile, and thus destroyed by boiling for 10 min.

Question 26

The botulism toxin has ___ types; which are most common??

Answer 26

7 types; A thru G. type A, B, and E are most common

Question 27

Which clostridia toxin is absorbed by the intestine, carried by blood to peripheral nerve synapses, binds to a receptor, and blocks the release of acetylcholine by interfering with proteolytic processing?? a - tetanus toxin b - botulsim toxin c - exotoxin A + B d - Alpha toxin

Answer 27

This is the mechanism for Botulism toxin

Question 28

T/F: Botulism toxin exposure will result in fever

Answer 28

False. | Botulsim toxin will NOT CAUSE FEVER.

Question 29

T/F: botulism will cause an altered mental status

Answer 29

FALSE, botulsim toxin will not have any effect on mental status

Question 30

the incubatio period for botulism toxin is ___ to ____ hours/days/weeks

Answer 30

18 to 36 hours

Question 31

T/F: botulsim toxin will result in sesnory deficit

Answer 31

False. Botulsim = NO SENSORY DEFICIT

Question 32

Which clostridium syndrome is characterized by flaccid paralysis of peripheral nerves symmetrically, dysphagia, dilated pupils, diplopia, and dry throat?

Answer 32

C. Botulinum, botulism

Question 33

T/F: you can diagnose botulism by culturing the microorgannisms

Answer 33

FALSE. the preformed toxin is the culprit - better to detect the toxin in feces, vomit, serum, or via serology for diagnosis.

Question 34

Patient has botulism!! - what do you do?

Answer 34

1. Remove toxin from stomach w/ lavage 2. Treat with Antitoxin (specific) - usually type A, B, + E 3. May need respiratory support

Question 35

Another clinical variant of botulism with more subtle symptoms and caused by honey as a source of contamination is:

Answer 35

Infant Botulism

Question 36

In wound-associated botulism, the contamination comes from:

Answer 36

Spores in soil get into wound -> germinate -> toxin

Question 37

A common cause of antibiotic-associated diarrhea is:

Answer 37

C. Difficile, due to toxin mediated coloninc inflammation

Question 38

C. Difficle is found in ___% of general population GI tract

Answer 38

3%

Question 39

___% of hospitalized patients are colonized vie the shitty-oral route from dirty hospital people

Answer 39

30%

Question 40

C. Difficle pathogenesis:

Answer 40

1. Antibiotic suppression of local flora -> C. Difficle proliferation 2. Exotoxin A produced -> binds to gut receptor 3. Exotoxin B produced -> cytotoxin -> damages colonic mucosa -> pseudo membrane formation + bloody diarrhea

Question 41

Which clostridium toxin acts by ADP-ribosylating 'Rho', a GTP- binding protein? ``` a - Tetanus toxin b - Botulism toxin c - Exotoxin A d - Exotoxin B e - Alpha toxin ```

Answer 41

d - Exotoxin B this causes the bloody diarrhea and pseudomembrane formation associated with C. Difficle infection.

Question 42

Pateint has a hx of antibiotic use, and yellow-white plaque pseudomembrane on colonoscopy; what toxin might you detect in a stool sample to confirm your diagnosis?

Answer 42

exotoxin B. ELISA can also be used to detect toxins of C. Difficile.

Question 43

You have diagnosed a pt with a C. Diff infection, you decide to treat by:

Answer 43

1. Stopping any offending antibiotics | 2. Treating with metroidazole, vancomycin, or fidaxomicin

Question 44

C. perfringens organisms are primarily found in ______ but also in ________________________

Answer 44

Soil, but also in human GI tract + Vaginas

Question 45

Two 'syndromes' of C. Perfringens are:

Answer 45

1. Gas Gangrene - invasive and rapidly progressing necrosis | 2. Food poisoning - self limiting diarrhea

Question 46

The alpha toxin produced by c. perfringens is a _________, it damages host cell membranes including capillary walls and RBCs

Answer 46

Lecithinase.

Question 47

The byproduct(s) of c. perfringens anaerobic growth:

Answer 47

1. H2 | 2. CO2

Question 48

The enterotoxin associated with C. Perfringens is part of the

Answer 48

Spore Coat. It is released into intesting after a large qty (10^8) of spores are consumed.

Question 49

The clinical syndrome of superficial cellulitis, necrotizing cellulitis, necrotizing fasciitis, and myositis/myonecrosis is caused by which Clostridia species?

Answer 49

C. Perfringens; this is gas gangrene

Question 50

C. Perfringens diarrhea lasts about _____ hours/days, and is characterize by abdominal cramps ad watery diarrhea.

Answer 50

8-22 hours

Question 51

Treatment for gas gangrene would include:

Answer 51

1. Surgical wound debridement 2. Penicilliin 3. Hyperbaric O2

Question 52

to diagnose c. perfringens food poisoning you would need to:

Answer 52

detect enterotoxin by ELISA of stool or food

Question 53

In addition to the Alpha Toxin - Lecithinase - what other enzymes are involved in the development of gas gangrene by C. Perfringens?

Answer 53

Collagenase, Hyaluronidase