Anaerobes

Question 1

Gram pos cocci

Answer 1

-Peptostreptococcus
-Anaerococcus
-Finegoldia
-Peptoniphilus

Question 2

Gram neg cocci

Answer 2

Veillonella

Question 3

Gram neg bacilli

Answer 3

-B fragilis group
-Porphyromonas
-Prevotella
-Fusobacterium

Question 4

Gram pos bacilli spores

Answer 4

-Clostridium

Question 5

Gram pos bacilli no spores

Answer 5

-Actinomyces
-Lactobacillus

Question 6

O2 requirements per culture type

Answer 6

Obligate aerobe = 15-21% O2 (AFB, fungi)
Microaerophile = 5% O2 (Campy, Helico)
Facultative anaerobe = good w/ or w/o O2 (Staph, Strep, Enterob.)
Aerotolerant anaerobe = Reduced O2 (Prop, Lacto, Clost.)
Obligate anaerobe = 0% O2 (Bacteroides, Clost, Fuso, Pepto, Porphyro)
Capnophile = 5-10% CO2 (Haemo, Neisseria, some ana)

Question 7

Anaerobic culture

Answer 7

1) exclude O2, low redox, prevent oxidation
2) H2 and catalyst -> O2 removed by formation of H2O
–methylene blue indicator -> colorless if anaer environment
3) Media
–BAP stored in Ana jar (NOT in fridge)
–Enriched BHI, Brucella, or Laked blood agar
4) Selective media
–KV (kan/vanc) for GNR
–KVL (kan/vanc/laked) (Bacteroides / Prevotella)
–Neo/Vanc BAP for Fuso, Veillonella
–Neo BAP for Clost, aGPC
–Nagler egg yolk for Clost
–BBE bile esculin (20% bile, gentamicin)
–PEA (suppress facult. GNR)
5) Liquid media
–chopped meat glucose or supplemented BHI
–supplemented thio

Question 8

B. fragilis group

Answer 8

1) pale GNR
2) Bile esculin + (grow in 20% bile)
3) Not inhibited by kan
4) PenR (differentiating characteristic)
5) Butyric acid=
6) Large colony on KVLB / aBAP
7) Black on BBE
8) Indole +/=

-KVLB+
–KanR, VancR, ColR
-BBE+
-Cat+

-Infection when organism enters peritoneal cavity

Question 9

Prevotella melaninogenica (formerly B. melaninogenicus)

Answer 9

-Glu=
-Black on KVLB / aBAP
–KanR, VancR
–Colistin var
-Nit=
-NG on BBE
-Pale GNCB
-Red under UV light at 366 nm
-Capsule

-Necrotizing anaerobic pneumonia
-Periodontal disease

Question 10

B. ureolyticus

Answer 10

-Translucent pitting colonies on aBAP
-No growt on BBE or KVLB

Question 11

Fuso. nucleatum

Answer 11

-thin, tapered GNR
-inhibited by 20% bile
-greening around colonies after air exposure
-acid from glu fermentation
-Chartreuse under UV light
-Ground glass, breadcrumb colonies
-Indole+

-KVLB var.
–VancR, KanS, ColistinS

-Necrotizing anaerobic pneumonia
-Periodontal disease
-Abdominal and pelvic abscesses
-Ear infection

Question 12

B. ureolyticus

Answer 12

-Translucent pitting colonies on aBAP
-No growth on BBE or KVLB

Question 13

Porphyromonas

Answer 13

-Brick red fluorescence
-NG on KLVB
–VancS, KanR, colistinR
-Indole+

Question 14

Prop. acnes

Answer 14

-GPR nonspore
–looks like diphtheroid on GS
-NSF -> common blood culture contam
-Can cause bacteremia / subacure endocarditis
-Indole+
-Cat+
-Produces propionic acid

Question 15

Prop. propionicus (aka Arachnia propionica aka Pseudoprop. proionicum)

Answer 15

-Actinomycosis
-Pleomorphic
-Rough colony
-Branched
-Cat=
-Indole=
-Use fluorescent Ig technique to diff from Actinomyces
-Glu+ w/ production of propionic acid

Question 16

Eubacterium/Eggerthella

Answer 16

-Pleo GPR
-No branching
-Indole=
-Nitrate+
-Produces butyric acid

Question 17

Actinomyces

Answer 17

-Straight / slightly curved bacilli of varying lengths
-Thin, branching filaments
-Can look beaded due to irregular staining
-Cat=
-Indole=

Question 18

Actinomyces disease

Answer 18

1) Actinomycosis
–Chronic granulomatous -> sinus tracts and fistula that erupt to the surface and drain pus
–“Sulfur granules”
–Branching
–Disease in maxillary region of throat/sinuses “Lumpy jaw”
–IUD infection
–Molar tooth colony

Question 19

Clostridium perfringens

Answer 19

-Large, irregular colony with double zone of beta hemo on aBAP
-Large, boxcar shaped rods
-Spores not usually seen
-Nonmotile
-Nagler’s test -> inhibition by antiperfringens antitoxin of the precipitate around growth on egg yolk agar

Question 20

C. perfringens disease

Answer 20

1) Food poisoning
-Type A - mild and self-limiting
-Type C - serious but rare
–Enteritis necroticans
–5-6 hours to bloody diarrhea and vomiting
–necrotic inflammation of the small intestine
–15-25% fatality rate
-Enterotoxin
-Meats and gravies

2) Gas gangrene
-alpha exotoxin (lecithinase)
-11 other destructive enzymes

Question 21

Clostridium ramosum

Answer 21

-Thin curved GVR
-Spores rarely seen
-Indole=
-Gel=
-Glu+

Question 22

Clostridium tetani

Answer 22

-Tennis racket / Lollipop terminal spores
-Swarms
-Motile
-Gel+
-Glu=
-Endospores introduced through wound

-Tetanospasmin neurotoxin prevents release of neurotransmitters (GABA and glycine)

Question 23

Clostridium difficile

Answer 23

-Chartreuse fluorescence
-Subterminal spores
-Motile
-Pseudomembranous colitis
-Abx therapy decreases normal flora, allows C diff to produce toxins
–Toxin A enterotoxin
–Toxin B cytotoxin
-Bloody diarrhea, mucous, necrosis of intestine

Question 24

Clostridium botulinum

Answer 24

-Neurotoxin -> fatal food poisoning
-Blocks release of acetylcholine from nerve terminals
-Flaccid paralysis
-Transmitted by heat-resistant endospores
-Motile flagella

Question 25

Veillonella

Answer 25

-Tiny GNC
-Convex, translucent colonies
-Red under UV light but fades rapidly
-NG on KVLB
-Indole=

Question 26

Peptococcus niger

Answer 26

-Only species left in Peptococcus genus
-Cat+
-Black colonies
-Rare

Question 27

Peptostreptococcus anaerobius

Answer 27

-SPS-S

Question 28

Pep. asaccharolyticus

Answer 28

-Indole+