Clostridia

Question 1

Clostridium is strictly ____(aerobic/anaerobic) gram - ____(positive/negative) rod that produces ____.

Answer 1

anaerobic; positive; endospores

Question 2

What is responsible for disease symptoms in clostridium patients?

Answer 2

proteinaceous toxins

Question 3

what disease is caused by C. difficle?

Answer 3

pseudomembranous colitis

Question 4

T/F. Clostridium is easy to culture.

Answer 4

False. “difficult clostridium”

Question 5

Pseudomembranous colitis presents with yellow plaques containing ___ and ___ ___ in ulcers of colonic mucosa.

Answer 5

fibrin; cellular debris

Question 6

What is the current leading cause of nosocomial diarrhea?

Answer 6

pseudomembranous colitis

Question 7

How is pseudomembranous colitis transmitted?

Answer 7

endospore

Question 8

T/F. C. difficile spores are resistant to antibiotics and when the spores vegetate the toxin production begins resulting in diarrhea.

Answer 8

True.

Question 9

Does C. difficile invade the bowel wall?

Answer 9

no.

Question 10

What two toxins does C. difficile produce?

Answer 10

enterotoxin (toxin A) and cytotoxin (toxin B)

Question 11

Both toxins act in the ___ of host cells to glycosylate ___-binding proteins. This causes the cells to lose _____ structure and die.

Answer 11

cytoplasm; GTP; cytoskeletal

Question 12

ELISA detection of which toxin is diagnostic?

Answer 12

Toxin A

Question 13

where is C. perfringens found?

Answer 13

soil (except sahara desert) and intestinal tract

Question 14

what are the four conditions that cause the spores of C. perfringens to germinate?

Answer 14

1. anaerobic
2. compromised blood supply
3. calicum ions
4. availability of peptides and amino acids

Question 15

Toxins produced by C. perfringens cause ____ that can lead to ___ ___, a necrotizing, gas-forming process of muscle associated with system signs of shock.

Answer 15

cellulitis; gas gangrene

Question 16

how many toxins does C. perfringens produce?

Answer 16

12

Question 17

which toxin damages the cell membranes and cause gas gangrene?

Answer 17

alpha toxin (lecithinase)

Question 18

How dose alpha-toxin (lecithinase) cause gas gangrene?

Answer 18

Phospholipase type C hydrolyzes phosphatidylcholine and sphingomyelin that leads to cell death

Question 19

Reddish blue to black color appears when muscle tissue is destroyed and gas bubbles are present in a process called ____.

Answer 19

myonecrosis

Question 20

T/F. Shock and renal failure result with C. perfringens patients and if not treated there is 100% mortality rate.

Answer 20

True.

Question 21

How is C. perfringens treated?

Answer 21

surgical removal to muscle tissue, antibiotics, antitoxin (horse), high oxygen concentrations, prompt care to restore arterial blood supply.

Question 22

A patient has been experiencing diarrhea for 2 days after recently consuming contaminated meat. From your readings (lol) you suspect that they are suffering from the third most common type of food poisoning in the US. You remember that this organism produces an enterotoxin in the intestines. What is the cause and how would you treat this disease?

Answer 22

C. perfringens - food poisioning

Self-limiting and disappears in 1-3 days

Question 23

Where is C. botulinum found?

Answer 23

soil and marine sediments

Question 24

C. botulinum has ___-resistant spores (not ___) that often survive food processing.

Answer 24

heat; toxins

Question 25

what condition is needed for C. botulinum spores to germinate and grow?

Answer 25

anaerobic conditions (such as canned foods)

Question 26

What is the causative agent of botulinum?

Answer 26

intoxication of ingestion of pre-formed toxin (don't need organism to be present)

Question 27

which clostridium is considered a bioweapon or bioterriorism threat?

Answer 27

botulinum

Question 28

How many neurotoxins does botulinum produce?

Answer 28

8 (A, B, E are the most common in humans)

Question 29

what is the mechanism of action for C. botulinum?

Answer 29

it prevents the release of acetylcholine neurotransmitter therefore interfering with neurotransmission at peripheral cholinergic synapses

Question 30

What is the role of zinc metalloprotease?

Answer 30

it cleaves protein involved in docking of neurotransmitter vesicles

Question 31

What symptoms are seen in patients with botulinum infection?

Answer 31

flaccid paralysis within 12 hours cranial nerves affected 1st (double vision, difficulty swallowing) respiratory failure as paralysis descends

Question 32

What are the three types of botulism?

Answer 32

food-born, wound (rare) and infant

Question 33

Which type of botulism is caused by ingestion of preformed toxin in foods that have not been canned or preserved properly?

Answer 33

food-borne botulism

Question 34

Which type of botulism occurs due to intestigal colonization of organisms in infants younger than 1 year, has a slow onset, hypotonic "floppy" state with a favorable outcome?

Answer 34

infant botulism

Question 35

what is the treatment for c. botulinum?

Answer 35

trivalent antitoxin (horses) administered ASAP

Question 36

T/F. Antibiotics are necessary for C. botulinum infecitons.

Answer 36

False. Organism need not be present. Ingestion of toxin causes the disease.

Question 37

which type of clostridium is found in soil, has spores resistant to environment and causes infection in traumatic wounds?

Answer 37

C. tetani

Question 38

T/F. Neonatal contamination of the umbilical cord at delivery can cause infection with C. tetani.

Answer 38

true.

Question 39

what is the major toxin in C. tetani?

Answer 39

tetanospasmin

Question 40

C. tetani attahces to ____ nerves near worund and transmit to ___ nerve nuclei. It inhibits ____ release leading to reflex spasms and spastic paralysis.

Answer 40

peripheral; cranial; GABA

Question 41

what condition occurs in 80% of patients infected with C. tetani?

Answer 41

Trismus "lockjaw" - tetanic spasm of masseter muscles that prevents opening of the mouth

Question 42

What other symptoms can be seen in patients with C. tetani?

Answer 42

rigiditiy of abdomen and stiffness of extremities tonic seizures respiratory failure from chest muscle paralysis

Question 43

T/F. There is no vaccine for C. Tetani.

Answer 43

False. C. tetani is completely preventable with DPT vaccine

Question 44

what is administered along with antitoxin to prevent further paralysis?

Answer 44

penicillin G