Specimen Handling Flashcards
Importance of Pretreatment and optimum temperature for culture
- Release fungi enclosed within cells.
- Concentrate fungal material in the specimen.
- Help to reduce or eliminate bacteria present in contaminated specimens
three mucolytic agents
a. N-acetyl-L-cysteine
b. 5% oxalic acid
c. Dithiothreitol (Sputolysin2)
Temperature requirements for blood and CSF culture:
30-37oC
Temperature requirements for Dermatological (ie., skin, hair, nails) culture:
15-30 oC
Pretreatment of abscess, drainage, pus, granules
Granules - washed & crushed
other materials - centrifuge at 2,000g for 10min.
Pretreatment of Blood, bone marrow
Lysis in Isolator tubes
centrifugation for 30min. at 3,000g, in a 35o fixed-angle rotor or swing bucket.
Pretreatment of Body fluids
Centrifugation at 2,000g for 10min. or membrane filtration
In body fluids, blod clots should be
teased apart
Pretreatment of nails
Mince
Gently pushed pieces down into agar.
Pretreatment of Respiratory secretions (BAL, sputum)
Lysis with mucolytic agents
centrifugation at 2,000g for 10min.
Pretreatment for Tissue for zygomycetes and other molds
mince, push down into agar
Pretreatment for tissue for recovery of H. capsulatum
grind, push pieces into agar
Pretreatment for urine
Centrifugation at 2,000g for 10min.
pretreatment of urine is best for recovery of
deep mycoses
All work in mycology should be carried out in a
type 2 laminar airflow BSC
recommended for personnel working with clinical specimens that may contain dimorphic fungi.
BSL2
Petri plates should NEVER be used if C
Coccidioides immitis
Do not make slide cultures of isolates that may be:
- Histoplasma capsulatum
- Blastomyces dermatitidis
- Coccidioides immitis
- Coccidioides posadasii
- Paracoccidioides brasiliensis
- Talaromyces marneffei
- Cladophialophora bantian
disinfect blood collection site with
iodine tincture or chlorhexidine
All systems for bacteria blood culture will recover all yeasts except
Malassezia spp
bone marrow is collected kn
heparinized syringe or lysis-centrifugation tube
Collection procedure: Abscess (Drainage, exudate, pus, wound)
Clean surface with 70% alcohol. Collect from active peripheral
edge with sterile needle and syringe. If open, use swab system or aspirate.
Processing procedure: Abscess (Drainage, exudate, pus, wound)
If thick, pretreatment similar to sputum specimen
Transport time and Temperature: Abscess (Drainage, exudate, pus, wound)
If ≤2h, RT
Collection procedure: Blood
Disinfect skin with iodine tincture or chlorhexidine prior to obtaining. Use max. volume of blood recommended for the system used.
Transport time and Temperature: Blood
≤2h, RT; if longer, RT but process in ≤16h (lysis- centrifugation)
All systems for bacteria in blood culture will recover all yeasts except for:
Malassezia spp.
Collection procedure: Bone marrow
Collect aseptically in a heparinized syringe or lysis-centrifugation tube.
unacceptable bone marrow specimen
Clotted
Transport time and Temperature
If ≤15min., RT; if longer RT
Collection procedure: Catheter tip
Remove distal 3-5 cm of line tip and place in a sterile container.
Transport time and Temperature: catheter tip
If ≤15min., RT; if longer,4oC
Collection procedure: hair
hair root is most important, plucking is best; submit 10-12 hairs in sterile dry container or envelope.
Collection procedure: skin
scrape with dull edge of a scalpel or glass slide, or vigorously brush in a circular motion with soft-bristle brush.
Collection procedure: Nails
clip or scrape with scalpel. Material under nail should also be scraped. Submit in sterile container or envelope.
Processing procedure: cutaneous
All specimens should be pressed gently into the agar with a sterile swab, do not streak agar plates. If used, toothbrushes should be pressed gently into agar as well.
Transport time and Temperature: Cutaneous
≤72h., (very stable) Never refrigerate, as dermatophytes are sensitive to cold.
processing procedure for For pityriasis versicolor (M. furfur)
olive oil or a paper disc saturated with olive oil should be placed on the first quadrant of agar plate.
Collection procedure: corneal scraping
taken by physicians and media(slides) inoculated directly.
Collection procedure: Vitreous humor
needle aspiration.
Processing procedure: Corneal scraping
inoculate non-inhibitory media in X- or C-shape motion.
Processing procedure: Vitreous humor
concentrate by centrifugation, use sediment for media and smears.
Transport time and Temperature: eye
≤15min., RT; if longer RT
Collection procedure: Medical devices
Collected surgically. Transport in sterile container.
Processing procedure: Medical devices
Use sterile scalpel to collect (by scraping) biofilm or vegetative growth.
Transport time and Temperature: Medical devices
≤15min., RT; if longer, 4oC
Collection procedure: Prostate fluid
Have patient empty bladder and then massage prostate gland to yield fluid.
Processing procedure: Prostate fluid
Inoculate media directly or transport in sterile wide mouth container.
Transport time and Temperature: Prostate fluid
If ≤15min., RT; if longer RT
Collection procedure: Lower respiratory tract (sputum, bronchial aspirate, BAL fluid)
Use first morning sputum collected after brushing teeth. Collect brushing and BAL fluid surgically. Place all samples in sterile containers. Inoculate media containing antimicrobial agents with and without cycloheximide.
Processing procedure: Lower respiratory tract (sputum, bronchial aspirate, BAL fluid)
Viscous lower respiratory specimens should be pretreated and centrifuged to concentrate their contents.
Transport time and temp: Lower respiratory tract (sputum, bronchial aspirate, BAL fluid)
If ≤2h., RT; if longer, 4oC
unacceptable specimens in lower respiratory tract
Saliva and 24h sputum
Collection procedure: Upper respiratory tract (Oral, oropharyngeal, and sinus samples)
Swab oral lesions, avoiding tongue.
Use thin wire or flexible swab or oropharynx.
Collect sinus contents surgically.
Processing procedure: Upper respiratory tract (Oral, oropharyngeal, and sinus samples)
Use swab transport system for oral and oropharyngeal samples.
Place sinus contents in sterile container.
Transport time and Temperature: Upper respiratory tract (Oral, oropharyngeal, and sinus samples)
Oral: if ≤2h, RT; if longer, RT
Sinus: if ≤15min. RT; if longer, RT
elective media and chromogenic media in Upper respiratory tract (Oral, oropharyngeal, and sinus samples) are best for recovery of
Candida spp.
Collection procedure: Sterile body fluids (CSF and pericardial, peritoneal, and synovial fluids)
Collect as for bacteriology. Concentrate by centrifugation, and use
sediment for inoculation. Clots should be grounded.
Processing procedure: Sterile body fluids (CSF and pericardial, peritoneal, and synovial fluids)
Except CSF
put sterile body fluids in sterile Vacutainer tubes with heparin or lysis-centrifugation tube to prevent blood clotting.
blood culture bottles can be used for recovery of yeast
Transport time and Temperature: Sterile body fluids (CSF and pericardial, peritoneal, and synovial fluids)
If ≤15min., RT; if longer, RT; never refrigerate.
The use of this specimen should be discourage.
Stool
Collection procedure: Tissue
Collected surgically. A larger volume is needed than for Bacteriology.
Processing procedure: Tissue
Use sterile container, keep moist (saline drops) to prevent drying.
recommended for invasive disease.
tissue biopy
Collection procedure: urine
First morning clean catch, suprapubic, or catheterized
specimens; 24-h specimens are unacceptable.
Processing procedure: urine
Use a sterile container or urine transport system. Concentrate specimens by centrifugation, and use sediment for inoculation.
Transport time and Temperature: urine
If ≤2h, RT;
if longer, 4oC;
urine transport systems can stay at RT for up to 72h.
Collection procedure: vaginal
Collect as for bacteriology.
Processing procedure: urine
Swab transport system or sterile container for washings.
Transport time and Temperature: urine
If ≤2h, RT; if longer, RT
