Clostridia

Question 1

clostridium bacteria are gram _____ and _____ anearobes

Answer 1

positive, strict

Question 2

Clostridium are known to produce endospores, what is their function

Answer 2

its a virulence mechanism putting them in a metabollically “inactive state” meaning it protects them from adverse conditions and will remain inside spores untill optimal conditions return

Question 3

what triggers the induction of spore formation in Clostridia

Answer 3

unfavorable environmental conditions

Question 4

what are the 4 subspecies of Clostridium that can cause disease in humans

Answer 4

C. difficile
C. perfringens
C. botulinum
C. tetani

Question 5

C. difficile is responsible for the leading cause of what?

Answer 5

nosocomial diarhea

-meaning usually associated w/antibiotics

Question 6

what virulence mechanism does C. difficile use to cause diarhea

Answer 6

Toxin A (Enterotoxin=fluid loss)
Toxin B (Cytotoxin)

Question 7

How could you diagnose C. difficile

Answer 7

ELISA detection of Toxin A

Question 8

what makes up a pseudomembrane

Answer 8

fibrin + dead cells (via Toxin B)

Question 9

What common disease is associated w/C. perfringens

Answer 9

gas gangrene

Question 10

How does C. perfringens cause Gas gangrene

Answer 10

produces 12 toxins, specifically

Alpha-toxin (lecithinase)

Question 11

What bacteria produces Alpha-toxin lecithinase, and what does it do

Answer 11

C. perfringens

-damages cell membranes causing gas gangrene

Question 12

which bacteria causes a disease that has a 100 percent mortality rate if left untreated, what is it ?

Answer 12

C. perfringens

-gas gangrene

Question 13

What species of clostridium can cause food posioning

Answer 13

C. perfringens from an enterotoxin produced

Question 14

how do you treat an infection caused by C. perfringes casusing gas gangrene

Answer 14

surgical removal/amputation

Question 15

what is significant about the spores produced by C. botulinum

Answer 15

spores are heat-resistent, meaning can survive food processing (canning)

Question 16

what type of toxins does C. botulinum produce, and what is their mechanism of action

Answer 16

8 neurotoxins

• prevents release of Ach
• causing flaccid paralysis and then descends

Question 17

why would C. botulinum be a good bioweapon

Answer 17

lethal dose is less than 1 ug

-heat resistent spores

Question 18

what species of Clostridia causes flaccid paralysis w/in 12-36 hours

Answer 18

C. botulism

Question 19

what are the 3 types of Botulism

Answer 19

• Food-borne botulism
• wound botulism
• infant botulism (less than 1 yr.)

Question 20

how would one be exposed to C. botulinum

Answer 20

eating canned goods containg the toxins

Question 21

how do you treat C. botulinum and why are antibiotics NOT neccesary

Answer 21

• trivalent antitoxin (from horses)

- Antibiotics do NOT work b/c you are ingesting toxins from canned goods, not actual bacteria

Question 22

what is clostridiums main virulence mechanism

Answer 22

produces endospores

Question 23

what is the major toxin produced by C. tetani

Answer 23

tetanospasmin

Question 24

how does C. tetanani major toxin of tetanospasmin affect the body

Answer 24

• toxin attaches to neurons around a wound
• inhibits neurotransmitter release of GABA
• causes spastic paralysis and reflex spasms

Question 25

Which bacteria causes flaccid paralysis and which casuses spastic paralysis ?

Answer 25

Flaccid - C. botulinum

Spastic - C. tetani

Question 26

During a C. tetani infection, where are symptoms first located or felt

Answer 26

Rostrally causing Trismus or “lockjaw”

Question 27

what bacteria can cause lockjaw

Answer 27

C. tetani

Question 28

how can you prevent C. tetani

Answer 28

with a DPT vaccine

-T stands for etanospasmin toxin