Gram Positive/Negative Anaerobes Flashcards Preview

Pathology > Gram Positive/Negative Anaerobes > Flashcards

Flashcards in Gram Positive/Negative Anaerobes Deck (49):
1

Clostridium perfringens diseases

- Gas gangrene
- Food poisoning
- Intra-abdominal infection

2

Clostridium tetani diseases

Tetanus

3

Clostridium botulinum diseases

Botulism

4

Clostridium difficile diseases

Nosocomial GI infection

5

Propionobacterium acnes diseases

Acne
Infection of prosthetics

6

Actinomyces diseases

Abscess formation

7

Peptostreptococcus diseases

Mixed contiguous infections

8

What are the spore forming Gram positive anaerobes?

Clostridium

9

What are the non-spore forming Gram positive anaerobes?

P. acnes
Actinomyces
Peptostreptococcus

10

What are the Gram negative anaerobes?

Bacteriodes
Fusobacterium
Prevotella
Porphyromonas

11

Bacteroides fragilis diseases

Abscess formation with mixed infection

12

Fusobacterium nucleatum diseases

Pneumonia or lung abscess with potent endotoxin

Liver abscess

13

Fusobacterium necrophorum diseases

Metastatic infection that is due to high virulence because of its endotoxin

14

Prevotella diseases

Female GU tract infections
Oral and GI tract infections

Often causes mixed infections

15

Porphyromonas diseases

Oral and periodontal infections

16

What anaerobes cause mixed infections?

Bacteroides fragilis
Prevotella

C. perfringens
Peptostreptococcus

17

What is the best antibiotic for anaerobic Bacteroides infection?

Metronidazole

18

What is the main toxin of C. perfringens and what is its function?

Alpha Toxin.

It lyses inflammatory cells and protects C. perfringens
from attack by WBCs which leads to gas gangrene where no live WBCs can be found in the blisters.

19

What is the onset of gas gangrene?

Rapid onset

20

How does C. perfringens cause gas gangrene?

Effects of the exotoxins released:
– necrosis of muscle and skin
– tense edema
– bullae formation
– gas formation

21

How does C. perfringens cause food poisoning?

Spores contaminate food which is ingested and enterotoxin produced following germination of large numbers of organisms leads to disease 8-24 hrs later

22

How is C. tetani spread?

– puncture wounds
– burns

23

How does C. tetani cause tetanus?

Releases tetanospasmin, a neurotoxin that blocks postsynaptic inhibition spinal motor reflexes (GABA) leading to spasmotic contractions

24

What does C. tetani look like under the Gram stain?

Tennis rackets

25

What is the manifestation of C. tetani infection?

Axonal transport of toxin with variable manifestations that develops into generalized tetanus preceded most commonly by trismus

26

What is a frequent source of C. botulinum infection?

Home canning of fruits/vegetables/fish

27

What causes botulism?

Preformed toxin with spore contamination.

It does not require spore germination.

28

What are some manifestations of botulism?

Descending paralysis (flaccid) - 1st symptoms are lack of eye movement

29

What is the major mechanism for C. difficile infection?

Patients in hospitals on antibiotics

30

What is megacolon?

Megacolon - colon can enlarge and dilate leading to
perforation that could kill patient

31

How does C. difficile cause its disease?

It produces and enterotoxin and a cytotoxin

32

What does C. septicum cause?

Nontraumatic myonecrosis and bacteremia

33

What does C. sordellii cause?

Fatal toxic shock syndrome following medical
abortions and natural child birth

34

What infection is Actinomyces associated with?

Slow growing- abscess forming in cervicofacial, thoracic, pelvic, intraabominal locations

35

What infection is Propionobacterium acnes associated with?

Acne
Prosthetic Devices

36

What is Peptostreptococcus associated with?

Often found among mixed infections like brain, intraabdominal, lung

37

What is the hallmark of B. fragilis infection?

Abscess formation
– Inflammatory response to infection
– Encapsulated “pus”

38

What are the main virulence factors of B. fragilis?

- Polysaccharide Capsule
- O2 Tolerance

39

What is the function of the B. fragilis toxin?

Nothing. It is defective.

40

How does B. fragilis infection normally occur?

Stool infection of a wound

41

What are the characteristics of Prevotella?

– Non-motile
– Non-encapsulated
– Strict anaerobe

42

What infections do P. bivia and P. disiens cause?

Female genital tract infections

43

What infections does P. melaninogenica cause?

Oralcavity, urogenital, GI tract

44

What is the best antibiotic for Fusobacterium infection?

Metronidazole

45

What is the best antibiotic for Peptostreptococcus infection?

Penicillin

46

What infections does Porphyromonas cause?

Mixed or single oral, periodontal infections

47

What infections does Fusobacterium nucleatum cause?

• aspiration pneumonia, lung abscess, empyema, chronic otitis media, sinusitis, brain abscess
• liver abscess

48

What is the main virulence factor of Fusobacterium?

High virulence toxin

49

What infections does Fusobacterium necrophorum cause?

• Lemierre’s syndrome/ post anginal sepsis
• widespread metastatic infection

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