Bacteriology Exam 11 (Anaerobes Flashcards
1
Q
What is an obligate anaerobe?
A
Requires 0% oxygen to grow
2
Q
What is an obligate aerobe?
A
Requires 15-23% oxygen to grow
3
Q
What is a facultative anaerobe?
A
Requires 0-23% oxygen (can grow with or without)
4
Q
What is a capnophilic organism?
A
Requires 5-10% CO2
5
Q
What is an aerotolerant organism?
A
Requires reduced oxygen
6
Q
What is a microaerophilic organism?
A
Requires 5% oxygen
7
Q
Where would obligate aerobes vs obligate anaerobes grow in a tube?
A
Obligate aerobes - top
Obligate anaerobes - bottom
8
Q
Where would facultative anaerobes vs aerotolerant anaerobes grow?
A
Facultative - all throughout the tube, mostly at top
Aerotolerant - throughout the tube
9
Q
Are endogenous or exogenous organisms more common cause of human disease?
A
Endogenous
10
Q
Anaerobic environments should consist of what?
A
85% nitrogen
10% CO2
5% Hydrogen gas
0% oxygen
11
Q
What are the clinical signs of anaerobic infection?
A
Pus producing
Infection near mucosal surface
Infection that persists despite aminoglycoside therapy
Foul odor
Large quantities of gas
Presence of sulfur granules
Infection secondary to human or animal bite
12
Q
Unacceptable samples for anaerobe testing
A
Throat swabs
NP swabs
Most sputums
Mouth swabs
Feces
Midstream or catheterized urine
Exposed wounds
13
Q
Acceptable samples for anaerobe testing
A
Aspirated body fluids
Tissue biopsy
Aspirated pus
Surgical samples
Eswabs
Sterile body site fluids
Suprapubic aspirates
14
Q
What is an example of a medium to transport anaerobes in to the lab?
A
Cairy Blair medium
15
Q
What are Eswabs stored in?
A
Amies liquid
16
Q
How long do Eswabs maintain anaerobic conditions?
A
48 hours at room temp
17
Q
What is PRAS?
A
Pre-reduced, anaerobically sterilized transport media
18
Q
At what nm is fluorescence observed under UV light?
A
366 nm
19
Q
What additional nutritional requirements are required for anaerobic plates?
A
Vitamin K
Hemin
Yeast extract
20
Q
What are types of anaerobic plates?
A
CDC ANA/Brucella (non selective blood agar)
BBE (bacteroides bile esculin)
KVLB (Kanamycin and Vancomycin with Laked Sheep Blood)
PEA
CNA
Cooked meat broth
Thioglycolate broth
21
Q
What is CDC ANA agar useful for?
A
Best for detection of anaerobic GPC
Useful for hemolysis detection
22
Q
What is BBE agar useful for? What does it contain?
A
Contains gentamicin and bile to inhibit most aerobes and anaerobes
Helps to identify B. frag group and bile tolerant bacteroides spp.
23
Q
What color will B. frag group turn on BBE agar?
A
Turns agar black
24
Q
What is Brucella agar most useful for?
A
Best for GNR
25
What is KVLB agar most useful for? What does it contain?
Bacteroides and Prevotella spp., yeasts, and Kanamycin resistant GNR
Contains Kanamycin that inhibits most GNR
Contains Vancomycin that inhibits most GPO
Contains laked blood that facilitates Prevotella pigmentation (black/brown)
26
What is PEA agar most useful for?
Grows mostly gram positive organisms
Selective media to suppress Enterobacteriaceae
27
What is CCFA agar useful for? What does it look like?
Growth of C. diff with yellow ground glass colony morphology and horse stable odor
28
What do anaerobic containers contain? What is the purpose of each?
Catalyst (removes O2)
Desiccant (Removes condensation)
Anaerobic gas with H2, CO2, N
Indicator (Methylene blue or Resazurin)
29
If the indicator turns pink (Resazurin) or blue (Methylene blue) what does this mean?
This means oxidation has occurred and oxygen has gotten into the anaerobic conditions
30
If the indicator stays colorless, what does this mean?
This means the indicator was reduced and no oxygen is in the anaerobic conditions which is good
31
When can plates be examined if using anaerobic closed chambers? When can they be examined if using anaerobic jars or pouches?
Closed chambers - after 24 hours
Jars/bags - after 48 hours
32
How long are anaerobic cultures held for?
5-7 days
33
If an organism grows on CO2 plates and Aerobic plates, but not anaerobic plates, what is it?
Obligate aerobe
34
If an organism grows on CO2 plates only, but not anaerobic or aerobic plates, what is it?
Capnophile
35
If an organism grows on CO2 plates, aerobic, and anaerobic plates, what is it?
Facultative anaerobe
36
If an organism grows on anaerobic plates, but not CO2 or aerobic plates, what is it?
Obligate anaerobe
37
What rapid biochemical testing is typically done on Anaerobes?
Fluorescence under UV light
Catalase
Spot indole
Urease
Motility
Antimicrobial disks (Kanamycin, vancomycin, colistin disks)
SPS disks
38
What is Egg Yolk agar selective for?
C. perfringens
39
Positive vs negative lecithinase test
Positive: appearance of white, opaque, diffuse zone that extends into the medium surrounding the colonies
Negative: absence of that zone extending from the edge of the colony
40
Positive vs negative lipase test
Positive: appearance of an iridescent sheen
Negative: absence of an iridescent sheen
41
What anaerobes are gram positive and spore forming?
Clostridium sp.
42
Where are Clostridium species naturally found?
Soil
43
What is Clostridium species very close to and hard to tell apart from? what is the difference?
Bacillus sp.
Bacillus is aerobic
Clostridium is anaerobic
44
What Clostridium sp. have a terminal spore? (of interest)
C. tetani
45
What Clostridium sp. have a subterminal spore? (of interest)
C. botulinum
C. difficile
46
What spore forming organism that we discussed has a central spore, but is aerobic?
Bacillus
47
C. perfringens: Swarming? Double zone hemolysis? Fluorescence? Gram stain? Spore location? Motility? Lecithinase? Lipase? Urease?
Swarming: NO
Double zone hemolysis: YES
Fluorescence: NO
Gram stain: POS
Spore location: SUB TERMINAL
Motility: NO
Lecithinase: POS
Lipase: NEG
Urease: NEG
48
What organism has a double zone of hemolysis?
C. perfringens
49
What organism has a "box car" gram stain morphology?
C. perfringens
50
T/F: C. perfringens is CAMP POS
False; it is REVERSE CAMP POS
51
C. perfringen sens/resis to vancomycin and kanamycin
Sensitive to both
52
Disease associations with C. perfringens
Gas gangrene
Food poisoning
Necrotizing bowl diease --> Pig bel disease
53
What is Pig Bel disease?
Associated with C. perfringens --> complication of infection by the Type C strain, mistaken sometimes as the 24 hour bug
54
What organism is the positive Nagler test used for? What is it?
C perfringens, positive result is lecithinase activity after streaking plate with organism and reagent (C perfringens type A antitoxin)
55
What type of hemolysis does the reverse camp test display for C. perfringens?
Bow tie zone of hemolysis towards GBS
56
C. Difficile: Swaming? Double zone hemolysis? Fluorescence? Gram stain? Spore location? Motility? Lecithinase? Lipase? Urease?
Swarming: NO
Double zone: NO
Fluorescence: Chartreuse YES
Gram stain: POS
Spore location: ST
Motility: YES
Lecithinase: NEG
Lipase: NEG
Urease: NEG
57
What is the primary stool pathogen identified on CCFA agar with a yellow ground glass colony?
C. diff
58
T/F: C. diff can be normal flora in up to 20% of people In US
True
59
What odor does C. Diff give off?
Horse stable odor
60
What can C Diff cause?
Diarrhea and if not treated can lead to megacolon and pseudomembranous colitis
61
What toxins does C diff release?
Toxin A and B
62
What type of stool must C diff be tested on?
Runny stools only
63
T/F: C diff is always an infection
False; some people can naturally be colonized without issues
64
How do you read the C diff Quik Chek Complete?
MUST be a dotted line in the Control area to be valid!
Solid line for Ag = positive Ag
Solid line for Tox = positive tox
No dotted line in C = INVALID
65
C. DIff treatment
Take patient off antibiotic causing CDAD
Give metronidazole and vancomycin
66
C. tetani: Swarming? Double zone hemolysis? Fluorescence? Gram stain? Spore location? Motility? Lecithinase? Lipase? Urease?
Swarming: YES
Double zone hemolysis: NO
Fluorescence: NO
Gram stain: POS
Spore location: Terminal
Motility: YES
Lecithinase: NEG
Lipase: NEG
Urease: NEG
67
What does C. tetani cause?
Tetanus aka lockjaw - RIGID PARALYSIS
68
What vaccine aid in the prevention of C. tetani?
TdaP and DtaP
69
Natural environment of C. tetani
Soil
70
What organism produces "drum stick" gram stain morphology?
C. tetani
71
What toxin does C. tetani release? What does it block?
Tetanospasmin; blocks release of neurotransmitters, glycine, and GABA
72
C. botulinum: Swarming? Double zone hemolysis? Fluorescence? Gram stain? Spore location? Motility? Lecithinase? Lipase? Urease?
Swarming: YES
hemolysis: NO
Fluorescence: NO
Gram stain: POS
Spore location: ST
Motility: POS (neg sometimes)
Lecithinase: NEG
Lipase: POS
Urease: NEG
73
What is the only lecithinase positive clostridium discussed? What is the only lipase positive clostridium discussed?
Lecithinase: C. perfringens
Lipase: C. botulinum
74
What does C. botulinum cause?
Botulism - FLACCID PARALYSIS
75
What toxin does C. botulinum release? What does it block?
Botulin toxin, blocks release of acetylcholine release from receptor
76
Where is C. botulinum naturally found?
Soil
77
How is C. botulinum often transmitted?
Through ingestion of spores from improperly canned vegetables and gardening
78
How to treat Botulism?
Penicillin
79
What clostridium species has a medusa head colony morphology and is associated with carcinoma of the colon?
C. septicum
80
What organisms discussed fluoresce chartreuse under UV light?
Fusobacterium and C. diff
81
What organisms discussed fluoresce brick red under UV light?
Prevotella sp
82
What are the anaerobic non-spore forming GPRs discussed?
Actinomyces, Bifidobacterium, Eubacterium, Lactobacillus, Mobiluncus, Propionibacterium
83
What anaerobic GPR has a spider-like, wooly, breadcrumb, or molar tooth colony morphology?
Actinomyces sp.
84
Where is actinomyces normally found?
Normal flora of oral cavity, tonsillar crypts, dental plaque, intestinal and female genital tracts
85
What is Actinomycosis?
Chronic granulomatous infection that causes development of sinus tracts containing sulfur granules
86
What type of infections does Actinomyces cause?
Oral cavity infections/female genital tract infections
87
Where is bifidobacterium normally found?
Vaginal area and colon
88
What organism has a "Y" shape gram stain described as rods with forked or "bifurcated ends"
Bifidobacterium
89
What anaerobic GPR has (+) 48 hr colony <1 mm, rough colonies, is branched, and has A L S as GLC products?
Actinomyces
90
What anaerobic GPR is negative for all biochemicals noted and has A and L as GLC products?
Bifidobacterium sp.
91
Where is Eggerthella found? What does the gram stain look like?
Normal flora of the colon
GS looks like "birds in flight"
92
Pinpoint alpha hemolytic colonies are growing on aerobic and anaerobic plates. It is normal flora of the vaginal canal and catalase negative. What is it?
Lactobacillus sp
93
where is Propionibacterium sp. normally found
Normal flora of the skin
94
What are the anaerobic GNR we discussed?
Prevotella, Fusobacteria, Bacteroides
95
What bacteria are long, thin, rods with tapered ends?
Fusobacterium sp.
96
Fusobacterium: vancomycin and kanamycin R or S? Red fluorescence? Chartreuse fluorescence?
Vancomycin R
Kanamycin S
Red fluorescence = neg
Chartreuse = pos
97
What disease does Fusobacterium cause?
Lemierre's syndrome, infectious thrombophlebitis of the internal jugular vein, resembles strep throat
98
What organism has a ground glass appearance colony?
Fusobacterium nucleatum
99
Does fusobacterium grow on KVLB?
No
100
What organism has a fried egg appearance colony?
Fusobacterium necrophorum
101
Does Fusobacterium necrophorum grow on KVLB?
Yes
102
What is Lemierre's syndrome cause by?
F. necrophorum
103
Where is F. necrophorum normally found?
Body cavities
104
Where is F. nucleatum normally found?
Gingival margin and sulcus
105
What are the most prevalent anaerobes isolated from infections?
B. frag group (GNR)
106
What Bacteroides group exhibits a high degree of antibiotic resistance?
B. frag
107
Will Bacteroides grow on KVLB? BBE?
Both
108
Does B. frag fluoresce?
No
109
Vancomycin/Kanamycin/Colistin - B frag group
R to both
110
What color will B. frag be on BBE? Why?
Black because it hydrolyzes esculin
111
How to differentiate B. fragilis from B. thetaiotamicron from B. uniformis?
B. fragilis is the only indole negative in B. frag group
B. uniformis will not grow on BBE while the others will
112
What group of anaerobes pits the agar?
B. uerolyticus group
113
What is the only Bacteroides that is urease pos?
B. ureolyticus
114
What is characteristic of all bile-resistant bacteroides?
Able to grow on BBE
Resistant to Colistin, Kanamycin, and Vancomycin - grows on KVLB
115
What group is bile resistant? What group is bile sensitive/tolerant?
Bile resistant - B. frag
Bile sensitive - B. ureolyticus
116
Where are bacteroides normally found?
Colon
117
What organism(s) fluoresces brick red under UV light?
Porphyromonas sp. and Prevotella sp
118
Porphyromonas: growth on KVLB?
No because sensitive to VAncomycin
119
What is the colony morphology/color of Porphyromonas on ANA blood agar?
Black to brown pigmented due to the production of protoheme
120
What plates will Prevotella grow on?
KVLB only. (R to Kanamycin and Vancomycin)
Not BBE (Bile sensitive)
121
What sp produce protoporphyrin during metabolism of Hemin, producing a brown black colony?
Prevotella sp
122
What organisms produce protoporphyrin?
What organisms produce protoheme?
Protoporphyrin - Prevotella
Protoheme - Porphyromonas
123
How to tell Prevotella and Porphyrmonas apart?
Prevotella grows on KVLB (R to vanco) and produces protoporphyrin
Porphyromonas does not grow on KVLB (S to vanco) and produces protoheme
124
Prevotella disease associations
Periodontal diseases
125
What organism has a fish eye colony morphology on BBE?
Bilophilia wadsworthia
126
Does Bilophilia fluoresce?
No
127
Bilophilia disease associations/normal area on body
Normal flora of colon
Causes intraabdominal abscesses and gangrenous perforated appendicitis
Associated with appendicitis
128
What is the anaerobic GPC we discussed? What is the anaerobic GNC we discussed?
Peptostreptococcus = GPC
Viellonella = GNC
129
Peptostreptococcus (Kanamycin and Vancomycin R or S, does it fluoresce?)
Kanamycin S
Vancomycin S
No fluorescence
130
Where is normal site for Peptostreptococcus?
Vaginal area, umbilicus, colon, GI
131
Normal site for Veillonella sp?
Normal flora of the oral cavity
132
How is Veillonella sp identified?
Gram negative cocci staining
Normal flora of the oral cavity
Nitrate reduction +
Catalase +
Red fluorescence
133
What does Veillonella sp look like on CDC ANA?
Very very tiny pinpoint easy to miss
134
What are most anaerobe infections treated with?
Metronidazole or clindamycin/penicillin
135
Anaerobic GPR that are spore forming
Clostridium
136
Anaerobic GNR
Bacteroides
Fusobacterium
Prevotella
137
Anaerobic GNC
Veillonella
138
Anaerobic GPR that do not form spores
Actinomyces
Bifidobacterium
Eubacterium
Lactobacillus
Propionibacterium
139
Anaerobic GPC
Peptostreptococcus
