26. Anaerobic Bacteria Most Commonly Isolated from Infection Flashcards Preview

Elsevier Bacteriology (RVSP) > 26. Anaerobic Bacteria Most Commonly Isolated from Infection > Flashcards

Flashcards in 26. Anaerobic Bacteria Most Commonly Isolated from Infection Deck (51):
1

Sensitivity of aerotolerant anaerobes to O2

>5% O2

2

Anion that is lethal to strict anaerobes

Superoxide (SO) anion

3

Enzyme produced by facultative and aerobic bacteria that converts SO to H2O2 and O2

Superoxide dismutase (SOD)

SO --SOD--> H2O2 + O2

4

System lacking in strict anaerobes to use O2 as terminal electron acceptor

Cytochrome system

5

The means by which energy is produced by strict anaerobes

Fermentation

6

Microscopic characteristics of Peptostreptococcus

Gram-positive cocci in chains

7

The only genus of gram-positive anaerobic cocci involved in disease

Peptostreptococcus

8

Microscopic appearance of Veillonella

Gram-negative cocci

9

Microscopic appearance of Propionibacterium

Gram positive bacillus

10

Resembles Corynebacterium in morphology and arrangement

Propionibacterium

11

Acid produced by Propionibacterium

Propionic acid

12

Causative agent of acne vulgaris (pimples)

Propionibacterium acnes

13

Microscopic appearance of P. acnes

Gram-positive rod/bacillus

14

P. acnes is a common resident in the

Pilosebaceous glands of the human skin

15

P. acnes is highly susceptible to

β-lactam antimicrobial agents (Penicillin G)

16

Microscopic appearance of Actinomyces israelii

Gram-positive bacillus
Tends to form branches
Sometimes with beaded appearance

17

Oxygen requirements of A. israelii

Aerotolerant anaerobe

18

Drugs for A. israelii

Penicillin class

19

Disease caused by A. isralii

Lumpy jaw

20

Gram-positive anaerobic cocci in chains

Peptostreptococcus

21

Gram-positive, non-spore forming, anaerobic rod

Propionibacterium acnes

22

Gram-positive bacillus that may form branches or have a beaded appearance

Actinomyces israelii

23

Gram-positive, non-spore forming, anaerobic bacillus

Propionibacterium

24

Gram-negative anaerobic cocci

Veillonella

25

Appropriate specimens for anaerobic culture

- Blood
- Other normally sterile sites (pleural fluid)
- lung
- dental/sinus
- soft tissue
- female genital tract
- abdomen (aspirate, peritoneal fluid)
- bone

26

How to transport tissue specimens for anaerobic culture?

- Anaerobic pouch
- Anaerobic transport tube with medium

27

How to transport fluid or aspirated pus for anaerobic culture?

- express into anaerobic transport vials
- leave in syringe, discard needle and cover with sterile cap

28

How to transport swabs for anaerobic culture?

Must be collected in a sterile surgical field then placed in a special anaerobic swab device

29

Characteristics of primary media used for anaerobic culture

Non-selective
Selective
Differential

30

All primary media for anaerobic culture must be supplemented with

Vitamin K
Hemin

31

Substances in media that keep O2 levels low

Reducing agents

32

Anaerobic media that selects for gram-negative anaerobic bacilli

Laked kanamycin-vancomycin (KV) blood agar

33

Anaerobic media that is differential/selective for Bacteroides fragilis

Bacteroides bile esculin agar (BBE)

34

Selective/differential media or recognition of C. difficile

CCFA

35

Component in CCFA that inhibits gram-negative bacteria

Cycloserine

36

Component in CCFA that inhibits gram-positive and gram-negative organisms

Cefoxitin

37

Appearance of C. difficile in CCFA

C. difficile ferments fructose resulting in yellow colonies

38

PEA is selective for

Gram-positive cocci and bacilli

39

Nonselective and differential medium that allows detection of lecithinase and lipase

Egg Yolk Agar (EYA)

40

Result of lecithin breakdown in EYA

Opaque precipitate

41

Effect of lipase on EYA

Iridescent sheen on colony surface

42

Phase of bacterial growth that anaerobes are most sensitive to O2

Log/exponential phase

43

Temperature for incubation of anaerobic culture

35-37°C

44

Indicators used to validate anaerobic conditions

Methylene blue
Resazurin indicator

45

Incubation time for anaerobic rapid growers

24 hours

46

Incubation time if Actinomyces is suspected

> 7 days

47

Microscope used to look at tiny anaerobic colonies

Dissecting microscope

48

Anaerobes not inhibited by 20% bile

Bacteroides
Bilophilia

49

Percent of H2O2 used in the catalase test for anaerobes

15% H2O2

50

Antibiotic disks that may be used for presumptive identification of anaerobes

Kanamycin
Vancomycin
Colistin

51

Sensitivity to O2 of strict anaerobes