Clostridium Flashcards Preview

D1S U1 Microbiology > Clostridium > Flashcards

Flashcards in Clostridium Deck (18):
1

Clostridium
1. Gram Stain?
2. Oxygen tolerance?
3. Produce what?

1. Gram positive rods
2. Strictly anaerobic
3. Endospores

2

Metabolically inactive state in which organisms can remain viable for hundreds of year. Resistant to adverse condition (heat, drying, radiation, chemicals). Caused by unfavorable environment. Readily germinate when conditions become favorable for vegetative growth.

Spores

3

"Difficult clostridium" (Not easy to culture). Leading cause of nosocomial diarrhea. Endospore transmission. Harbored in large intestine (dormant). Disease state usually associated with antimicrobial drugs (kills off everything else and allows this to grow)

C. Difficile

4

C. Difficile Toxins:

1. Toxin A- Enterotoxin (fluid production, damage to mucosa)
2. Toxin B- Cytotoxin (rounding of tissue-culture cells)

5

Both C. Difficile toxins act in cytoplasm of host cell to glycosylate _____, causing cells to lose cytoskeletal structure and die

GTP-binding proteins

6

Found in soil in intestinal tract of animals. Environmental pathogen. Major in wound infections (and war wounds). Local damage and systemic effects. Toxins -> Gas gangrene, necrotizing.

C. Perfringens

7

Type of wound that C. Perfringens thrives in:

1. Anaerobic
2. Compromised blood supply
3. Calcium ions
4. Availability of peptides and amino acids

8

C. Perfringens toxin that damages cell membranes and causes gas gangrene.

Alpha-Toxin (Lecithinase)

9

C. Perfringens Treatment/Prevention

1. Surgical removal of infected muscle
2. Antibiotics
3. Prompt care imperative

10

C. Perfringens is also the third most common type of food poisoning. Sporulating C. Perfringens produce ____ in intestines. -> Diarrhea

Enterotoxin

11

Lives in soils and marine sediments. Heat-resistant spores (not toxins), can survive food processing. Bioweapon. Toxins very poisonous.

Clostridium Botulinum

12

C. Botulinum toxin prevents release of ______. -> Paralysis

Acetylcholine Neurotransmitter

13

Three types of Botulism:

1. Food-borne
2. Wound botulism (rare)
3. Infant botulism

14

C. Botulinum Treatment

1. 25% mortality rate
2. Trivalent antitoxin (from horses) administered ASAP
3. Some permanent muscle damage
4. No antibiotics necessary (because it's the toxin only)

15

C. Tetani major toxin:

Tetanospasmin
(->tetanus)

16

Tetanospasmin attaches to peripheral nerves near wound and is transmitted to _____. Causes reflex spasms, spastic paralysis.

Cranial Nerve nuclei

17

Lockjaw caused by Tetanus.

Trismus

18

C. Tetani Treatment/Prevention:

1. Preventable with DPT vaccine
2. 11% mortality (respiratory failure)
3. Antitoxin and penicillin G (prevent further paralysis)
4. Surgical debridement of wound