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Flashcards in Anaerobes Deck (71)
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1

Where are anaerobes found?

Gut microbiome (esp. Bacteroides and Clostridia). Also found in oral cavity, skin, colon, female genital tract. Clostridia found in soil and air as spores too.

2

What 2 enzymes do anaerobes lack?

1. Superoxide Dismutase
2. Catalase

3

How do anaerobes get their energy?

Carbohydrate fermentation or breakdown of amino acids to amines.

4

Why do anaerobic infections stink?

B/c amines stink

5

Besides smelling awful, what are other characteristics to anaerobic infections?

Abscesses and tissue necrosis, smelly pus. Smelly breath. Many are polymicrobial.

6

What type of pneumonia are you thinking of with an alcoholic?

Aspiration of anaerobe

7

Many anaerobic infections are of what type?

Opportunistic: relocalized normal flora to a sterile area.

8

Why aren't feces or sputum cultured when anaerobic infection is suspected?

B/c it's just normal flora. Won't help you any.

9

Clostridial infections are usually from what?

Environmental spores

10

Shape of Bacteroides fragilis?

Gram Negative coccobacillus

11

What is the major virulence factor of B. fragilis?

Anti-phagocytic capsule

12

B. fragilis is a major component of what?

Human GI tract (opportunistic pathogen)

13

What is the MC anaerobic infection?

B. fragilis

14

What types of dz can B. fragilis cause?

1. Intra-abdominal infections
2. Abscesses
3. Pelvic Inflammatory Dz
4. Pulmonary infections (due to aspiration)

15

Treatment of B. fragilis abscesses?

1. Surgical drainage
2. DOCs: erythromycin, clindamycin, metronidazole, 3rd gen cephalosporins

16

What is B. fragilis resistant to?

Penicillin

17

Why aren't amino glycosides effective against anaerobes?

They don't work under anaerobic conditions.

18

Shape of Prevotella melaninogenica?

Gram Negative coccobacillus

19

What is the major VF of Prev mel?

Anti-phagocytic capsule

20

Where in the human body can you normally find Prev mel?

GI tract, nasopharynx, and vaj

21

What does Prev mel infection cause?

Pulmonary and Periodontal abscesses

22

What is the reason for Prevotella melaninogenica's name?

When cultured, forms dark black colonies (melanin).

23

Shape of Clostridium?

Gram + spore-forming rods (Note: must be G+ to form spores).

24

T or F. Clostridium is the only anaerobic endospore-forming bacteria.

T

25

What's advantageous about the spores of Clostridium?

They are resistant to high heat and harsh environments.

26

What is responsible for Clostridium's pathogenesis?

Exotoxins and secreted hydrolytic enzymes

27

Where is Clostridium found?

1. Colon
2. Soil as spores

28

What is the shape of C. perfringens?

Large, "boxcar" shaped G+ rods

29

Where is C. perf found?

Soil and intestines of humans and animals

30

Most human C. perf infections are from what?

Spores in soil or food