SPECIMEN MANAGEMENT Flashcards
True or false:
Appropriate collection technique : acute (early) phase of an illness
True
How soon should specimens be collected for viral infections?
Within 2-3 days
When should specimens be collected in relation to starting antimicrobials, antifungals, or antiviral medications?
Before these medications are started
How soon should specimens be transported after collection?
Within 2 hours of collection
What are the requirements for specimen containers during transport?
Containers must be:
leak-proof and transported within sealable
plastic bags with a separate section for paperwork
What label should be marked on specimen transport bags?
biohazard label
What additional measures might be required for transporting specimens?
Use of special preservatives, temperature-controlled conditions, or holding media
What preservative is used for urine specimens?
boric acid
Which preservatives are used for stool specimens intended for ova and parasite examination?
Polyvinyl alcohol (PVA) and buffered formalin
What are common transport or holding media for specimens?
Stuart’s medium and Amie’s medium
Why is charcoal added to some transport media?
TO ABSORB FATTY ACID
What anticoagulant is commonly used for specimen preservation?
0.025% Sodium polyanethol sulfonate (SPS)
Which anticoagulant is used for viral cultures
Heparin
True or false:
Citrate and EDTA can e used for specimen preservation
false
What is the recommended temperature for storing specimens in a refrigerator?
4°C
At what temperature should specimens be stored at ambient (room) temperature?
22°C
What is the storage temperature for specimens requiring body temperature conditions?
37°C
What are the recommended freezer temperatures for storing specimens?
-20°C or -70°C
What types of specimens are typically stored at 4°C?
Urine
Stool
Viral specimens
Sputum
swabs
foreign devices (catheters)
How long can serum for serologic studies be stored at -20°C?
1 week
What temperature is recommended for long-term storage of tissues or specimens?
-70°C
True or False:
Rejection criteria include specimens where information on the label does not match the request or the specimen is unlabeled.
True
True or False:
Specimens transported at improper temperatures may be rejected.
True
True or False:
Specimens not transported in the proper medium may be rejected.
True
True or False:
Insufficient quantity of specimens can lead to rejection.
True
True or False: Leaking specimens may be rejected.
True
True or False:
Specimens with transport times exceeding 2 hours post-collection or those not properly preserved may be rejected.
True
True or False:
Specimens received in a fixative like formalin, which kills microorganisms, may be rejected.
True
True or False: Specimens received for anaerobic culture from sites known to have anaerobes as part of the microbiota (e.g., vagina, mouth) may be rejected.
True
True or False:
Dried specimens are generally acceptable for processing.
False
True or False:
Specimens that would produce information of questionable medical value upon processing, such as Foley catheter tips, may be rejected.
True
According to processing guidelines, which specimens should be given priority when multiple specimens arrive simultaneously?
CSF, tissue, blood, and sterile body fluids
What action should be taken upon the arrival of a specimen in the laboratory?
Record the time and date of specimen receipt
What should a microbiologist do if a specimen arrives with multiple test requests but there is insufficient specimen volume to perform all tests?
Call the clinician to prioritize the testing
What is the initial step in processing specimens according to guidelines?
Perform a gross examination of the specimen
What characteristic of stool should be noted, which may indicate the presence of barium?
chalky white color
What aspect of the specimen’s status should be noted during gross examination?
Whether it is bloody, clouded, or clotted
What is the purpose of direct microscopic examination of a specimen?
To assess the quality of the specimen
True or False: Direct microscopic examination is commonly performed on throat, nasopharyngeal, or stool specimens.
False (Usually not performed on these types of specimens)
What is the most common staining method used in bacteriology for direct microscopic examination?
Gram staining
What are some common stains used for direct fungal examination?
1.KOH (Potassium hydroxide)
2. PAS (Periodic acid-Schiff)
3.GMS (Grocott’s methenamine silver stain)
4. calcofluor white
What are examples of common stains used for direct acid-fast staining?
1.Auramine rhodamine
2. Ziehl-Neelsen
3. Kinyoun
It is a liquid medium where nutrients are dissolved in water, and bacterial growth is indicated by a change from clear to turbid appearance.
Broth medium
example of pH indicator used in broth medium
phenol red
what indicator used in broth medium where They change color in the presence of metabolites, indicating bacterial activity.
pH indicator
It is a semisolid medium that provides an indication of the type of organism present based on oxygen requirements.
Thioglycollate broth
How are pH indicators such as phenol red used in broth medium?
They change color in the presence of metabolites
What is the purpose of thioglycollate broth in microbiological media?
provides an indication of the type of organism present based on oxygen requirements.
a solid medium used to solidify nutrients and water to support bacterial growth.
Agar
Most common solidifyng agent in agar
Agarose
Agarose melts at high temperatures (___°C) but resolidifies when the temperature falls below __°C.
High temp - >95 C
Low temp - below 50 C
What type of growth medium combines both liquid and solid phases?
Biphasic medium
How can the growth of bacteria in broth medium be detected?
By observing a change in the broth’s appearance from clear to turbid, indicating bacterial growth.
what culture media: contain nutrients that support the growth of most nonfastidious organisms and are nonselective but differential.
Nutritive media
Name 3 examples of nutritive media used for bacterial and fungal growth.
1.tryptic soy agar (bacteria)
2.nutrient agar plates for bacteria,
3. Sabouraud’s dextrose agar for fungi, as well as blood or chocolate agar.
These culture media contain specific nutrients needed for the growth of bacterial pathogens
supplemental or enrichment media
Culture media: Buffered charcoal-yeast extract (BCYE) for Legionella pneumophila.
Supplemental or Enrichment Medium
Culture media: They are specialized to enhance the growth of organisms present in low numbers, like anaerobes or those affected by antimicrobial therapy.
Enrichment broth
Culture media: Back up broth
Enrichment broth
What is an example of an enrichment broth used for anaerobic cultures?
- Thioglycollate broth (anaerobes)
- Brain heart infusion broth (BHIB)
- Tryptic soy broth (TSB)
- Gram negative broth
What is the purpose of LIM broth (Todd Hewitt broth with colistin and nalidixic acid)?
It is used for selective enrichment of organisms such as Streptococcus pneumoniae.
How do selective media distinguish between groups of organisms?
By incorporating antimicrobials, dyes, or alcohol to support the growth of one group of organisms while inhibiting another.