Specimen collection and processing Flashcards
are not recommended for collection because they do
not provide sufficient quantity, are easily contaminated, and
can become dried out, leading to loss of organisms
swabs
are appropriate for specimens from the upper
respiratory tract, external ear, eye, and genital tract.
swabs
list 3 problems that are usually present in the microbio lab
lesions, wounds, and abscess
is not an appropriate specimen source when the
exact anatomic site is not provided
wound
what are the most commonly obtained specimens?
urine, sputum, and stool
what specimen are often collected for the diagnosis of bacterial pneumonia?
sputum
what are the most difficult specimen to collect adequately because they are contaminated with oropharyngeal flora?
lower respiratory tract specimens
what is the term used for specimens obtained by patients rinsing their mouth with water and cough directly into sterile container?
expectorated sputum
what is the term used for specimens obtained by patient aerosolized droplets?
induced sputum
what is the specimen of choice for the detection of gastrointestinal pathogens?
stool
can be submitted for bacterial culture as long as fecal material is visible on the swab
Rectal swabs
if parasites are suspected, two specimens collected within 10 days should be sufficient. True or False?
False. It should be three
what is the appropriate ratio of stool to preservative?
1:3
appears as a white chalky substance in the specimen and masks the appearance of parasites under the microscope.
Barium
Specimen should be transported to the laboratory ideally within ____ of collection and preferably within ____
30 minutes; 2 hours
Urine, stool, sputum, bronchial secretions, swabs, and viral specimens can be maintained at what temperature?
refrigerator temperature - 4 degrees Celsius for 24 hours
Cerebrospinal fluid can be stores if not processed immediately for what temperature and time?
35 degrees Celsius and 6 hours
what two specimen types in which preservatives can be use?
urine and stool
is used in commercial products to maintain accurate urine colony counts
Boric acid
Stool specimens for bacterial culture that are not transported
immediately to the laboratory can be refrigerated; if the delay
is longer than 2 hours, the specimen can be added to?
Cary-Blair transport medium
Stools for ____ assay should be collected without preservative
Clostridium difficile
what is the most common anticoagulant used for microbiology specimens?
SPS or Sodium Polyanethol Sulfonate
_____ is another acceptable anticoagulant and is often
used for viral cultures and for isolation of _____
Heparin; Mycobacterium spp.
what anticoagulant are not accepted in the microbio specimens?
citrate and EDTA
what transport medium is commonly used?
Stuart or Amie
Some transport systems contain charcoal to absorb fatty
acids given off by the swab that can be detrimental to the
survival of?
Neisseria gonorrhoeae and Bordetella pertussis
Blood is usually placed into a __________ immediately after collection.
broth culture medium
also can be inoculated into blood culture broth bottles at the bedside
Synovial and peritoneal fluids
Specimens for N. gonorrhoeae can be placed directly onto a
commercial transport system such as the?
JEMBEC system
What category is capable of causing permanent disability or life-threatening or fatal disease in otherwise healthy
humans or animals upon exposure?
Category A
What category have substances are not in a form generally capable of causing permanent disability or life-threatening or
fatal disease in otherwise healthy humans or
animals on exposure?
Category B
What level of specimen prioritization is Amniotic fluid, blood, brain, csf, heart valves, and pericardial fluid?
Level 1 - Critical/Invasive
What level of specimen prioritization is Body fluids, bone, drainage from wound, feces, sputum, and tissue?
Level 2 - unpreserved
What level of specimen prioritization is catheter tip and urine?
Level 3 - Quantitation required
What level of specimen prioritization is feces in preservative, urine in preservative, and swabs in holding medium?
Level 4 - preserved
What level of specimen prioritization is classified as critical because they represent a potentially life-threatening illness and are from an invasive source and require immediate processing?
Level 1 specimen
what level of specimen prioritization is classified as unprotected and may quickly degrade or have overgrowth of contaminating flora?
Level 2 specimen
what level of specimen prioritization required quantitation?
Level 3 specimen
what level of specimen prioritization classified as where specimens that arrive in the laboratory in holding or transport media
Level 4 specimen
the analytic phase of lab testing process beings when the?
specimen is received in the lab
Gram stain of expectorated sputum reveals fewer
than ________________ and _________per low-power field and mixed bacterial flora.
25 white blood cells and 10 epithelial cells
________ of the specimen may provide useful
information to both the microbiologist and the physician
Gross appearance
What is useful tool that provides rapid information?
direct microscopic examination
support the growth of most non-fastidious microbes.
Nonselective media
What is the standard nonselective medium?
Sheep blood agar
support the growth of one type or group of microbes but not another
Selective media
what is the selective media for enteric gram-negative bacilli?
MacConkey agar
what is the selective media used for gram positive organisms?
Columbia agar with CNA
contain growth enhancers that are added to nonselective agar to allow fastidious organisms to flourish.
Enriched media
is a liquid medium designed to encourage the growth of small numbers of a particular organism while suppressing other flora present.
Enrichment broth
is used to enhance the growth of group B streptococci.
Lim broth
can be used as a supplement to agar plates to detect small numbers of most aerobes, anaerobes, and microaerophiles.
Broth media
Most specimens arrive in the lab are
swab, tissue, and fluid
Sterile pipette is used to dispense the inoculum onto
plates and broth. Tissues can be prepared for culture by?
Homogenization
can destroy certain organisms (i.e., fungal elements), in some situations the tissue is minced with sterile scissors and forceps into small pieces suitable for culture.
Homogenization
Specimens can be inoculated to agar plates by using a ________ to yield a semi quantitative estimate of growth
general-purpose isolation streak
what grows in ambient air?
aerobes
it cannot grow in the presence of oxygen and require an anaerobic atmosphere
anaerobes
grow with reduced oxygen and increased CO2 and can be isolated using jars or bags.
microaerophiles
Cultures for anaerobes and broth cultures may be held for?
5 to 7 days
have standardized processing procedures that are well established in the microbiology lab.
Routine specimens
mass spectrometry that enables definitive identification in a matter of minutes may change the approach that is taken in
the workup of cultures.
matrix-assisted laser desorption
have standardized processing procedures that are well established in the microbiology lab.
Routine specimens
is used in many laboratories. Using sterile forceps, a 5- to 7-cm
segment of the catheter is rolled across the surface
of a blood agar plate four times.
The Maki roll technique
post analytic phase of the laboratory testing process
Communication of lab findings
