F1. MICROBIOLOGY SECTION Flashcards
(48 cards)
1
Q
4 class of biosafety cabinets:
A
- Class I
- Class II
- Class IIA
- Class IIB
2
Q
- operated in open front
- consist of negative pressure
- allow room air to pass into cabinet & around the area & material within, sterilizing only the air to be exhausted
A
Class I
3
Q
- also called as Vertical Laminar Flow BSCs
- direct the flow of contaminated air into the filters
- air flows in “sheets”, which serves as a barrier to particle from outside the cabinet
A
Class II
4
Q
- self-contained
- 70% of air is recirculated
A
Class IIA
5
Q
- selected for radioisotopes, toxic chemicals, or carcinogenic samples
A
Class IIB
6
Q
- prokaryotic unicellular organisms
- lack nucleus & nuclear membrane
- may either be gram positive [violet] or gram negative [red/pink]
A
Bacteria
7
Q
single, closed, circular chromosomes of double-stranded DNA
A
Nucleoid
8
Q
small circular molecules of extrachromosomal circular DNA
A
Plasmids
9
Q
asexual reproduction of bacteria
A
Binary Fission
10
Q
Bacteria size?
A
0.2 to 2 um in diameter
1 to 6 um in length
11
Q
- Principal stain used for microscopic examination of bacteria
- First devised by Hans Christian Gram during the late 19th century
This staining divides most bacterial species into two large groups called?
A
Gram Stain
- Gram-positive
- Gram-negative
12
Q
take up the basic dye, crystal violet
A
Gram-positive
13
Q
allow crystal violet dye to wash out easily with decolorizer alcohol or acetone
A
Gram-negative
14
Q
Gram-positive’s:
1. cell wall?
2. lipopolysaccharide?
3. gram staining?
4. representation?
A
- thick [peptidoglycan]
- absence
- purple
- purple/violet result
15
Q
Gram-negative’s:
1. cell wall?
2. lipopolysaccharide?
3. gram staining?
4. representation?
A
- thin [peptidoglycan]
- presence
- red/pink
- pink result
16
Q
4 basic types of morphological types of bacteria?
A
- cocci
- bacilli
- spirilla
- vibrios
17
Q
spherical-shaped cells
round
A
COCCI
18
Q
rod-shaped cells
A
BACILLI
19
Q
spiral shaped cells
A
SPIRILLA
20
Q
comma-shaped cells
curved rod
A
VIBRIOS
21
Q
short rod
A
coccobacillus
22
Q
long, loose, helical spiral
A
spirochette
23
Q
2 types of bacterial metabolism?
A
- fermentation
- respiration
24
Q
Process by which bacteria catabolize carbohydrates to produce energy
A
Fermentation
25
- also known as **oxidation**
- Process of **bacterial energy generation** rather than fermentation
Respiration
26
Collection in microbiology needs to prioritize ____ and _____.
Safety and General Guidelines
27
- follows universal precaution throughout the collection & handling process.
- should wear gloves & a laboratory gown.
- eye protection
- accidents or injuries must be reported immediately
Safety
28
General guidelines?
- specimen should be from the **infection site**
- collected **before antimicrobials [antibiotics]** are administered
- **STERILE & ASEPTIC TECHNIQUE** of collection devices & containers
- **LABELLED** specimen container
29
# COLLECTION FORM VARIOUS BODY SITES
- tongue should be depressed
- swabbing between the **tonsillar pillars** and **behind the uvula**
- **cheek**, **tongue**, and **teeth should NOT be touched**
Throat [swabs]
30
**Expectorated specimens from deep cough** should be collected into a sterile specimen cup
Sputum
31
- ***Midstream clean-catch*** is the *most common collection method*
- ***Culture for catheterized urine specimens*** usually *have less contaminating bacterial flora*
Urine
32
- **2-3 cultures** should be collected at random times **during 24-hour period**
- **venipuncture**
* Skin is disinfected with ***70% alcohol, followed by Iodine***
Blood
33
volume of blood for Adults?
20-30mL of blood per culture is collected
34
volume of blood for infants?
1-5mL of blood per culture is collected
35
- Should be collected aseptically by **PHYSICIAN**
- Should be ***processed immediately*** and ***not exposed to heat or refrigeration***
CEREBROSPINAL FLUID
36
GENITAL TRACT:
1. **Exudates** may be expressed from the **urethral orifice** or a **small-diameter swab inserted 3-4 cm into the urethra**
2. sterile swab is inserted **into the cervix with an
aid of speculum** [remain fow a few seconds]
1. MEN (penile discharge)
2. WOMEN (vaginal discharge)
37
Anaerobic specimen can be transported using?
- anaerobic glass
- candle jar
38
specimens that are **not stored in the refrigerator if it is for microbiology**
1. temp. sensitive organisms
2. blood culture bottles
3. CSF
39
# Processing:
Culture Media Selection:
1. nutritive media
2. differential media
3. selective media
4. backup broth
5. specialized media
40
- **Support the growth of a wide range of microorganisms**
- considered nonselective
- **supports most growth of organisms**
## Footnote
examples of this media?
Nutritive media
## Footnote
1. blood agar plate
2. chocolate agar
41
Microorganisms that can be **distinguished on the basis if certain growth characteristics** evident on the medium
## Footnote
example of this media?
Differential media
## Footnote
blood agar plate
42
**Support the growth of one group of organisms**, but not another, by **adding antimicrobials, dyes, or alcohol** to a particular medium
## Footnote
Examples of this media:
1. only allow gram-negative organisms
2. only allow gram-positive organisms [CAN]
Selective media
## Footnote
1. MacConkey Agar
2. Columbia Agar w/ colistin & nalidixic acid Agar
43
- Also called **supplemental or enrichment broth**
- for **detection of small numbers of organisms present**
## Footnote
Example of this media?
1. THIO
2. BHIB
3. TSB
Backup broth media
## Footnote
1. Thioglycollate broth
2. brain-heart infusion broth
3. tryptic soy broth
44
Used when **specific organisms are suspected**
## Footnote
Example of this media?
1. TCBS
Specialized media
## Footnote
1. Thiosulfate-citrate-bile salts-sucrose agar
2. mannitol salt agar
3. bismuth sulfite agar
4. campylobacter agar
45
# INCUBATION
**Normal incubation temperature** for bacterial cultures
35°C-37°C
46
are **appropriate for incubation of anaerobic cultures**
- anaerobic jars/ bags
- anaerobic chamber
47
temp. for **stool cultures** for **detection of Campylobacter jejuni**
42°C to 45°C
48
Specimen rejection criteria
- nonsterile/contaminated specimens
- contaminated w/ barium/other foreign substances
- 24-hr. urine or sputum collections
- salive instead of sputum
- 2 hrs. unrefrigerated urine specimens or more post-collection
