Unit 3: Bacterial Diseases

Question 1

Endotoxin

Answer 1

• part of the outer portion of the cell wall in gram negative bacteria

-liberated when the bacteria dies and cell wall breaks apart

Question 2

Exotoxin

Answer 2

-mostly in gram positive bacteria as part of their growth and metabolism

• released into surrounding medium

Question 3

What are the 3 types of exotoxins?

Answer 3

1) superantigens
2) toxins
3) AB toxins

Question 4

Type 1: Superantigens

Answer 4

1) non-specifically stimulate many families of CD4+ T cells
2) lead to massive cytokine release

Question 5

Examples of superantigens

Answer 5

-Toxic shock syndrome toxin
-streptococcal mitogenic exotoxin
- streptococcal pyrogenic toxin

Question 6

Type 2: toxins

Answer 6

destroy host cells by distributing membranes

Question 7

Examples of toxins

Answer 7

• streptolysion pneumolysin
  -alpha toxin
  -beta toxin
• phospholipase C

Question 8

Effects of endotoxin on host

Answer 8

-luekocytes release cytokines leading to fever
-some cytokines damage blood vessel walls causing a drop in BD- which leads to shock
- activate innate system comprised of complement proteins that cause inflammation- which could drop BP leading to shock

Question 9

Causative agent of necrotizing fasciitis

Answer 9

Streptococcus Pyogenes
enters thru breaks in skin

Question 10

Alpha hemolysis

Answer 10

-Incomplete
-oxidizes iron in hemoglobin producing a “greenish” discoloration on blood plates

Question 11

Beta hemolysis

Answer 11

Complete destruction of red blood cells ; resulting in clearing around growth

Question 12

Gamma Hemolysis

Answer 12

No hemolysis ; results in no change in media

Question 13

What type of hemolysis does streptococcus pyogenes cause?

Answer 13

Beta hemolysis

Question 14

What exotoxin destroys neutrophils?

Answer 14

Streptolysin

Question 15

Bullae

Answer 15

Large fluid filled sac

Question 16

Ecchymosis

Answer 16

Subcutaneous bleeding

Question 17

Crepitus

Answer 17

Crackling sound under skin

Question 18

Necrosis

Answer 18

Death of soft tissue
Ex: skin, subcutaneous tissue, muscles

Question 19

Do clostridium tetani & clostridium botulinum require aerobic or anaerobic environment?

Answer 19

Anaerobic-no oxygen

Question 20

What structure do c.tetani & c.botulinum capable of forming when not in the right environment?

Answer 20

Endospores
C. Tetani =spore terminal
C. Botulinum = spore subterminal

Question 21

What type of exotoxins are botulinum toxin & tetanospasmin?

Answer 21

Neurotoxin

Question 22

What is the mechanism of botulinum toxin

Answer 22

Blocks release of acetylcholine at neuromuscular junction & form preganglionic sympathetic and pre and post ganglionic parasympathetic neurons

Question 23

What type of paralysis does botulinum toxin cause?

Answer 23

Flaccid paralysis = muscles cannot contract

Question 24

Nystagmus

Answer 24

Rapid, involuntary movement of eyes

associated w/ botulism

Question 25

What is Botox?

Answer 25

Botulinum toxin = ability to inhibit contraction of skeletal muscle

Question 26

Cosmetic uses for BOTOX

Answer 26

-frown lines -crows feet - under eye lines -forehead lines

Question 27

Strabismus

Answer 27

Eyes are not aligned *crossed*

Question 28

Blepharospasm

Answer 28

Sometimes chronic condition in which the eyelids uncontrollably twitch

Question 29

Where are endospores of C. Botulinum found?

Answer 29

Soil, ponds and lake sediments

Question 30

By what vehicle do the C. botulinum toxins get into humans?

Answer 30

Home-canned products that have been insufficiently heated

Question 31

Heat-labile w/ respect to botulinum toxin

Answer 31

Destroyed by heat *food must be ingested uncooked or be inadequately cooked for someone to get botulinum toxin*

Question 32

What is the anti-toxin for botulism and how does it work?

Question 33

Best way to prevent botulism?

Answer 33

Properly can food and eat cooked food

Question 34

Mechanism of action for tetanospasim

Answer 34

Blocks release of inhibitory neurotransmitters (glycine & y-aminobutyric acid -these stop the action of acetylcholine) at the neuromuscular junction

Question 35

What type of paralysis does tetanospasmincause?

Answer 35

Spastic paralysis = muscles cannot relax

Question 36

Trismus

Answer 36

Masseter muscles - inability to open jaw (lock jaw) *associated w/ tetanus*

Question 37

Opisthotonos

Answer 37

Back muscles paralysis *associated w/ tetanus*

Question 38

Where are spores of clostridium tetani found?

Answer 38

- soil (manure-treated especially) - intestinal tract of humans and other animals

Question 39

How do the spores of clostridium tetani get into humans?

Answer 39

Puncture wounds

Question 40

Best way to prevent tetanus

Answer 40

Not going outside barefoot & vaccines

Question 41

What is human tetanus immune globulin and how does it work?

Question 42

What is tetanus toxoid?

Answer 42

Inactivated toxin that retains antigenicity (what we get injected w/ as a vaccine)

Question 43

What combined vaccine is the tetanus toxoid apart of?

Answer 43

DTaP (it is the T part)