Culture Prep, Media, Gram stain, Terms Flashcards
1
Q
Regular/ambient
A
20-22°C room temp
2
Q
Increased CO2
A
Increased CO₂ to 10% (ambient air CO₂ is 1%)
3
Q
Anaerobic
A
All O₂ removed
4
Q
Microaerophilic
A
Orgs require partial pressure of O₂ less than atmospheric oxygen (21% O₂)
5
Q
Gas Pack jar
A
H₂O is added to generator and hydrogen and carbon dioxide gases are produced
6
Q
Anaerobic bags or pouches
A
O₂ removal system is initiated
7
Q
Anaerobic glove box
A
Vinyl is surrounding an area large enough for plates, specimens etc. The tech inserts hands into gloves inside of vinyl tent to prevent any O₂ from entry
8
Q
Capnophilic
A
Orgs that grow better in higher CO₂ levels than ambient %
9
Q
Halophilic
A
salt lover
10
Q
Psychrophiles
A
Optimal growth at 4°C
11
Q
Mesophiles
A
Optimal growth at 24-40°C
12
Q
Thermophiles
A
Optimal growth at 40-60°C
13
Q
Cary-Blair medium
A
Allows recovery of Salmonellae, Shigella, Vibrio cholerae, Campylobacter. Used with stool samples
14
Q
Culturette
A
Sterile specimen collection system that has a polyester swab and a plastic shaft. Transport media is in a glass ampule which is activated after the specimen has been put on the swab to moisten it.
15
Q
Calgiswab
A
Calcium alginate wool on a flexible aluminum nasopharyngeal swab
16
Q
Stuart’s or Amie’s medium
A
Viral transport media
17
Q
Autoclave
A
121.6°C 15 min at 15 PSI
18
Q
Filtration
A
0.22 um for critical sterilizing
19
Q
Dry heat
A
160-180°C 1.5-3 hrs
20
Q
Gas sterilization
A
Ethylene oxide
21
Q
Radiation
A
Ionizing radiation of gamma rays or electron beams
22
Q
State the purpose of the gram stain
A
To make visible the bacteria and determine gram stain reaction (pos or neg) and morphology
23
Q
State the principle of the gram stain
A
High lipid bacterial cell walls cannot retain the crystal violet through the decolorization stage and will stain red (gram neg), the others remain purple
24
Q
List the reagents used in the gram stain and the functions of each:
A
Crystal Violet - Purple stain that attaches to bacterial cell wall
Iodine/mordent - Drives crystal violet into cell
Decolorizer - Alcohol or Acetone alcohol, removes crystal violet from cell walls with high lipid content
Safranin - Stains cell walls with high lipid content red
25
Selective media
Allows one bacteria to grow and prevents the growth of another (MAC)
26
Differential media
Differential media: Helps group bacteria by a certain characteristic displayed on the media (MAC)
27
Enriched media
Growth enhancers are added to nonselective media which allows fastidious organisms to grow (CHOC)
28
Enrichment broth
Helps support a minority pop of bacteria to grow while suppressing another (Salmonella/Shigella broth)
29
Sheep Blood Agar (BAP)
Purpose:
Class:
Principle:
Purpose: Routine Media
Class: Non-selective
Principle: Tryptic Soy agar, 5-10% Sheep Blood
30
Phenylethanol Blood Agar (PEA)
Purpose:
Class:
Principle:
Purpose: Selective for Gram Pos Cocci
Class: Selective
Principle: Phenyl ethyl alcohol inhibits, Aerobic neg rods
31
Chocolate Agar (GC Medium Base)
Purpose:
Class:
Principle:
Purpose: Promotes growth of Haemophilus and other fastidious orgs.
Class: Enrichment
Principle: Contains cell-free Hgb, NAD and Sheep Blood
32
Eosin Methylene Blue
Purpose:
Class:
Principle:
Purpose: Isolation of Gram Neg rods
Class: Selective differential
Principle: E. coli - blue black colonies, Eosin Y and Methylene blue decrease +C growth
33
MacConkey
Purpose:
Class:
Principle:
Purpose: Isolation of Gram Neg rods
Class: Selective differential
Principle: Bile Salts and Crystal violet, inhibits positives
34
CNA
Purpose:
Class:
Principle:
Purpose: Isolation of Cocci
Class: Selective enrichment
Principle: Enriched with Sheep blood that the has antibiotics (colistin and naladistic acid to inhibit gram neg rods Trimethoprim which prevents Proteus swarming, Nystatin inhibits fungus)
35
XLD
Purpose:
Class:
Principle:
Purpose: Isolate and Recognize Lactose neg and H₂S pos organisms
Class: Selective differential
Principle: Shows lactose neg and H₂S producers
36
Salmonella-Shigella Agar (SS)
Purpose:
Class:
Principle:
Purpose: Isolate Salmonella and Shigella (not as well)
Class: Selective differential
Principle: Non lactose fermentors (colorless) and H₂S produces
37
Tergitol-7 Agar (Te-7)
Purpose:
Class:
Principle:
Purpose: To identify Lactose neg for Salmonella and Shigella isolation
Class: Selective differential
Principle: Lactose neg orgs. are visible
38
Hektoen Agar
Purpose:
Class:
Principle:
Purpose: To identify Lactose neg for Salmonella and Shigella isolation
Class: Selective differential
Principle: Lactose neg orgs. are visible
39
Campy-BAP
Purpose:
Class:
Principle:
Purpose:Selective for Campylobacter species
Class: Selective differential
Principle: Brucella agar base, antibiotics and sheep blood
40
Modified Thayer-Martin
Purpose:
Class:
Principle:
Purpose: Selection for Neisseia and inhibits normal flora
Class: Selective differential
Principle: Added growth factors, Vancomycin (inhibits +C), Colistin (inhibits gram neg rods), trimethoprim (prevents proteus), nystatin (prevents fungi growth)
41
HBT/V agar
Purpose:
Class:
Principle:
Purpose: Isolate Gardnerella vaginalis
Class: Non selective enrichment
Principle: Human blood will produce Beta hemolysis
42
SSA/SXT
Purpose:
Class:
Principle:
Purpose: Isolate S. pyogenes and S. agalactiae
Class: Selective
Principle: Bile salts and sodium sulfate inhibit Gram pos and neg rods
43
Anaerobic PEA
Purpose:
Class:
Principle:
Purpose: Helps gm+ and gm- nonsporalating anaerobes
Class: Selective
Principle: Add PEA and CDC anaerobic agar
44
Anaerobic KV
Purpose:
Class:
Principle:
Purpose: Isolation of obligate anaerobes particularly Bacteroides
Class: Selective
Principle: Addition of Kanamycin and Vancomycin to anaerobic BAP
45
Campy Thio
Purpose:
Class:
Principle:
Purpose: Allows Campylobacter to grow
Class: Selective enrichment
Principle: Brucella agar base (10%) antibiotic mixture
46
Thioglycolate
Purpose:
Class:
Principle:
Purpose: Help small #'s of orgs to grow, will support anaerobes
Class: All purpose broth
Principle: Thioglycolate, Cystine and sodium sulfite are reducing agents
47
GN Growth
Purpose:
Class:
Principle:
Purpose: Enhance the growth of Salmonella-Shigella
Class: Selective enrichment
Principle: Deoxycholate and citrate salts decrease growth of pos. orgs., increase mannitol to increase Salmonella-Shigella
48
Some thioglycolate media have indicators like resazurin or methylene blue. What is the function of the indicator?
The color indicates if the O₂ has been eliminated to support the growth of anaerobes. Thioglycolate, cystine and sodium sulfite are reducing agents - if boiled the O₂ will be driven off the top, leaving the bottom of the tube to support the anaerobes.
49
Name the organism it is used to isolate:
MacConkey with Sorbitol
E. coli O157:H7
50
Name the organism it is used to isolate:
Mannitol Salt Agar
Staph aureus
51
Name the organism it is used to isolate:
Tinsdale
Corynebacterium diptheriae
52
Name the organism it is used to isolate:
Lowenstein-Jensen
Mycobacteria
53
Name the organism it is used to isolate:
Bismuth Sulfite (BS)
Salmonella type and other Salmonella
54
Name the organism it is used to isolate:
Middlebrook 7H-10
Mycobacterium
55
Name the organism it is used to isolate:
Fletcher's Medium
Leptospira
56
Name the organism it is used to isolate:
BCYE (buffered charcoal-yeast extract agar)
Legionella
57
Name the organism it is used to isolate:
TCBS (Thio sulfate Citrate Bile salts Sucrose)
Vibrio
58
What is the usual percentage of blood used in preparing sheep blood agar plates:
5%
59
Name the best medium to Isolate the following organism from a mixed culture:
Staphylococcus aureus
Mannitol Salt agar
60
Name the best medium to Isolate the following organism from a mixed culture:
Streptococcus pyogenes
Selective Sheep Agar
61
Name the best medium to Isolate the following organism from a mixed culture:
Corynebacterium diphtheriae
Modified Tinsdale.
| Can also use Loeffler, Cystine-tellurite
62
Name the best medium to Isolate the following organism from a mixed culture:
Bacteroides fragilis
Anaerobic KV
63
Name the best medium to Isolate the following organism from a mixed culture:
Escherichia coli
EMB, Mac
64
Name the best medium to Isolate the following organism from a mixed culture:
Neisseria gonorrhoeae
MTM
65
Name the best medium to Isolate the following organism from a mixed culture:
Salmonella typhi
HE, XLD, TE₇
66
Name the best medium to Isolate the following organism from a mixed culture:
Shigella sonnei
HE, XLD, TE₇
67
Name the best medium to Isolate the following organism from a mixed culture:
Clostridium perfringens
BRU/BA - brucella/blood agar plate or Egg Yolk Agar
68
Name the best medium to Isolate the following organism from a mixed culture:
Vibrio cholera
TCBS
69
Name the best medium to Isolate the following organism from a mixed culture:
Vibrio parahemolyticus
TCBS
70
Name the best medium to Isolate the following organism from a mixed culture:
Campylobacter jejuni
Campy BAP
71
What are the regulations for mailing biologicals:
The biological agents must be placed in a securely closed watertight vial or test tube surrounded by absorbent material, then placed in a labeled secondary container.
72
Depending on this growth pattern, what would the direct gram stain be expected to be:
Growth on BAP, Choc, CNA
Gram Pos Cocci
73
Depending on this growth pattern, what would the direct gram stain be expected to be:
Growth on Mac only
Gram Neg Rod
74
Depending on this growth pattern, what would the direct gram stain be expected to be:
Growth on Choc only
Fastidious such as Neisseria: Gram neg diplococci
Or
Haemophilus: tiny gram neg rods
75
If this/these organisms were present, growth would be seen on these plates:
Staph aureus
BAP, Choc, CNA
76
If this/these organisms were present, growth would be seen on these plates:
Haemophilus influenzae
Choc
77
If this/these organisms were present, growth would be seen on these plates:
Bacillus spp.
BAP, Choc
78
If this/these organisms were present, growth would be seen on these plates:
Enterobacter aerogenes
BAP, Choc, Mac
79
If this/these organisms were present, growth would be seen on these plates:
Strep pyogenes and Corynebacterium spp.
BAP, Choc, CNA
80
If this/these organisms were present, growth would be seen on these plates:
Strep pneumoniae
BAP, Choc, CNA
81
If this/these organisms were present, growth would be seen on these plates:
Candida albicans
BAP, Choc
82
List the Four different Laboratory Biosafety Levels (BSL) and list a brief summary of each.
BSL 1: Agents that are well classified and not known to cause disease consistently in healthy adults.
BSL 2: Agents that pose a moderate potential hazard to employees and environment.
BSL 3: Agents that are indigenous or exotic, and pose a risk of aerosol transmission, with potential lethal consequences
BSL 4: Dangerous, exotic agents that have a high risk of causing life threatening infections. Building is isolated from other areas, protective suits usually required.
83
List some of the basic principles of specimen collection. (ex: collection procedures, labelling, safety, etc)
- Collect in acute phase, before antibiotics administered
- Collect using Dacron swabs, not cotton
- Collect by needle aspiration when possible
- If a patient collected specimen, make sure easy, thorough, written instructions are given
- Label firmly attached to container with appropriate information
- Specimen does not pose a safety risk to person opening it. Not leaking, secondary container for transport, etc.
84
Class: Selective differential medias
```
Eosin Methylene Blue
MacConkey
XLD
Salmonella-Shigella Agar (SS)
Tergitol-7 Agar (Te-7)
Hektoen Agar
Campy-BAP
Modified Thayer-Martin
```
85
Class: Selective media
Phenylethanol Blood Agar (PEA)
SSA/SXT
Anaerobic PEA and KV
86
Class: Selective enrichment media
CNA
GN Growth
Campy Thio
