Final; Clostridia

Question 1

What oxygen level does clostridium tolerate

Answer 1

strictly anaerobic

Question 2

clostridium are gram-positive rods that produce what

Answer 2

endospores

Question 3

How many clostridium species are responsible for human infections and are in the environment

Answer 3

~30 cause infection in humans

>50 are found in the environment

Question 4

What does clostridium produce that is responsible for disease symptoms

Answer 4

proteinaceous toxins

Question 5

This clostridium species causes pseudomembraneous colitis (PMC)

Answer 5

C. difficile

Question 6

This clostridium species causes cellulitis, gas gangrene, and food posioning

Answer 6

C. perfringens

Question 7

This clostridium species causes botulism

Answer 7

C. botulinum

Question 8

This clostridium species causes tetanus

Answer 8

C. tetani

Question 9

This is a metabolically inactive state in which organisms can remain viable for hundreds of years; making them resistant to adverse conditions

Answer 9

endospore

Question 10

What can cause endospore formation

Answer 10

unfavorable environment, of which when the environment becomes favorable then growth resumes

Question 11

This is a yellow plaque containing fibrin and cellular debris in ulcers of colonic mucosa and is the leading cause of nonsocomial dirrhea

Answer 11

psuedomembraneuous colitis

Question 12

True or False

C. difficile is harbored in a dormant state in the large intestine of small percentage of healthy humans in low numbers

Answer 12

True

Question 13

How is C. difficile transmitted

Answer 13

transmitted as the endospore via hands of health care personnel

Question 14

What is the disease state of C difficile associated with

Answer 14

antimicrobial drugs; spores are resistant to antibiotics of which will only kill the normal flora

Question 15

The spore produce what which results in diarrhea

Answer 15

produces a toxin; invasion of the bowel wall does not occur

Question 16

What is toxin A of C. difficile

Answer 16

enterotoxin; fluid production and damage to the mucosa

Question 17

What is toxin B of C. difficile

Answer 17

cytotoxin; round of tissue-culture cells

Question 18

How to toxin A and B of C. difficile act

Answer 18

act in the cytoplasm of the host cell to glycosylate GTP-binding proteins
the cell then loses cytoskeletal structures and dies

Question 19

This is found in the soil (except Sahara desert) and intestinal tract of animals and is a major pathogen of wound infections (especially war wounds)

Answer 19

C. perfringens

Question 20

What type of damage does C. perfringens inflict

Answer 20

local damage and systemic effects

invasive properties due to a variety of toxins produced

Question 21

Severe trauma introduces C. perfringens spores from that environment that germinate under what conditions

Answer 21

anaerobic
compromised blood supply
calcium ions
availability of peptides and amino acids

Question 22

Toxins produced by C. perfringens typically cause what

Answer 22

cellulitis that can lead to gas gangrene, associated with systemic signs of shock

Question 23

How many different toxins does C. perfringens produce and what is the main one

Answer 23

12

Alpha-toxin (lecithinase) damages cell membranes and causes gas gangrene

Question 24

How does alpha toxin of C. perfringens cause gangrene

Answer 24

it hydrolyzes phosphatidylcholine and sphingomyelin that leads to cell death
muscle tone is destroyed
shock and renal failure usually result (100% fatal is left untreated)

Question 25

What is the treatment and prevention for C. perfringens

Answer 25

``` surgical removal of infected tissue antibiotics to control antitoxin from horses (little effect) high oxygen concentrations prompt care in imperative ```

Question 26

This is the third most common type of food poisoning in the US

Answer 26

C. perfringens

Question 27

What causes the C. perfringens food poisoning

Answer 27

sporulatng C. perfringens produce enterotoxin in intestines of people who have consumed contaminated food causes diarrhea but disappears in 1-3 days

Question 28

This is found in soil and marine sediments and is the causative agent of botulism

Answer 28

C. botulinum

Question 29

What is special about the C. botulinum spores

Answer 29

They are heat-resistant which often survive food processing and germinate in an anaerobic condition

Question 30

How does C. botulinum cause botulism

Answer 30

the intoxication of ingestion of pre-formed toxin (do not need to organism to be present)

Question 31

True or False | botulism is not a bioweapon or bioterrorism threat

Answer 31

False; it is a threat

Question 32

What are the C. botulinum toxins

Answer 32

produces 8 neurotoxins (BoNT) serotypes A-g | and are among the most poisonous substances known* with one 1 component of the toxin

Question 33

What is the lethal dose of the C. botulinum toxins in humans

Answer 33

< 1µg

Question 34

What is the mechanism of the C. botulinum toxins

Answer 34

it prevents the release of acetylcholine neurotransmitter and cleaves the proteins involved in docking of neurotransmitters (zinc metalloprotease)

Question 35

What are the symptoms of C. botulinum toxin

Answer 35

flaccid paralysis within 12-36 hours cranial nerves affected first paralysis descends, respiratory failure

Question 36

This is the ingestion of preformed toxin in food that have not been canned or preserved properly

Answer 36

food-borne botulism

Question 37

This is the systemic spread of toxin produced by organisms inhabiting wounds

Answer 37

wound botulism (rare)

Question 38

This is the intestinal colonization of organisms in infants younger than 1 year, "floppy state" has a favorable outcome

Answer 38

infant botulism

Question 39

What is the current mortality rate, with good supportive care for botulism

Answer 39

25%

Question 40

What is the treatment for botulism

Answer 40

trivalent antitoxin from a horse | however some muscles may be permanently damaged

Question 41

This is ubiquitous in the GI tract of humans and animals, also in the soil (spore resistant to the environment), and infection is usually associated with traumatic wounds

Answer 41

C. tetani

Question 42

What is the major toxin of C. tetani

Answer 42

tetanospasmin

Question 43

Tetanospasmin is responsible for what

Answer 43

all symptoms of tetanus | similar structure to the botulism toxin

Question 44

How does tetanospasmin cause tetanus

Answer 44

attaches to peripheral nerve near wound and is transmitted to cranial nerve nuclei it inhibits neurotransmitter release (GABA) and inhibitory input results in reflex spasms and spastic paralysis

Question 45

This is the tetanic spasm of masseter muscle that prevents the opening of the mouth

Answer 45

trismus; lockjaw | seen in 80% of cases

Question 46

What are the symptoms of tetanus

Answer 46

paralysis descends to the neck and back muscles and produces rigidity of abdomen and stiffness of extremities tonic seizures respiratory failure due to paralysis of chest muscles

Question 47

What is used to treat/prevent tetanus

Answer 47

DPT (diptheria pertussis and tetanus) vaccine human globulin as passive immunity to tetanus-prone wounds surgical debridement of the wound to prevent bacterial growth

Question 48

What is the mortality rate of tetanus

Answer 48

11% | antitoxin should be administered immediately along with penicillin to prevent further paralysis