(P) Lec 5: Collection, Handling, and Processing Of Specimen Flashcards
All parts of the body exposed to the outside environment is inhabited by the
____ and specimens coming from these parts are considered ____.
Normal Microbiota
Non-sterile
Consists of non-pathogenic organisms but can be pathogenic once placed outside their normal habitat
Normal Micriobiota
Formerly known as normal flora
Specimens coming from body parts not exposed to the outside environment
Sterile Specimens
Sterile or Non-sterile Specimen?
✦ Cerebrospinal Fluid (CSF)
✦ Peritoneal Fluid
✦ Pericardial Fluid
✦ Pleural Fluid
✦ Blood
✦ Suprapubic Aspirate (SPA)
Sterile
Sterile Specimens
When cultured under normal conditions, there should be ____
no growth of microorganisms (absolutely negative)
Specimens coming from body parts exposed to the outside environment
Non-sterile Specimen
Sterile or Non-sterile Specimen?
✦ Urine
✦ Stool
✦ Sputum
Non-sterile
Normally, urine is ____ in the bladder
sterile
Collection via ____ is critical because there might be a possibility of contamination when performed incorrectly
midstream clean-catch
When is urine considered sterile?
When collected via suprapubic aspiration
What do MDs usually request prior to antibiotic therapy?
Culture & Sensitivity
Unless the objective is to monitor the treatment
Why is sepsis and exception to requesting C&S prior to antibiotic therapy?
Because administration of first line antimicrobials cannot be delayed
In automated blood culture machines, they have?
Antimicrobial Removing Device (ARD)
Blood C&S with ARD (antibiotic is already given but C&S is still requested)
In aseptic collections and sterile containers, there should be no ____
Contaminants
In microbiology, ____ will do except for blood culture
minimal amounts
In microbiology, minimal amounts will do except for ____
blood culture
This is to obtain a higher yield of isolates
Acute Stage of the Disease Process
Ideal TAT
Processed immediately after collection
Ideal TAT for critical specimens (coming from sterile site)
Within 15 mins after collection
Ideal TAT for non-critical (other) specimens
within 2 hours after collection
When processing, we should prioritize what type of specimen?
Critical
What should you process first?
Stool vs. Urine vs. Blood vs. CSF
Blood then CSF
If you are considering that the sample contains
microorganisms that are sensitive to drying, you should process them ____
immediately
Collection Methods
Suitable and done ONLY for aerobic organisms
Because the collection method is already exposed to oxygen
Cotton Swab (Swab Technique)
Advantage of cotton swab technique?
Common, easily available, easy to perform
Disadvantage of cotton swab technique?
Toxic to other organisms
If you are suspecting that the isolate is ____ (also sensitive to drying), note that cotton contains fatty acids that are toxic to the organism
Neisseria gonorrhoea
If there is no other choice besides cotton, what can you do when the isolate is Neisseria gonorrhoea?
Add charcoal so as to neutralize the toxic fatty acids present in the cotton
✦ Made of synthetic fiber, not cotton
✦ Highly absorbent, so the sample will not easily dry out
Rayon and Dacron Technique
Disadvantage of Rayon and Dacron?
Expensive and may not be readily available
◦ Any extraction can support the growth of aerobic and anaerobic culture, simply because
the method does not allow exposure of the specimen to oxygen
◦ Aerobic and anaerobic culture
◦ Ex: Peritoneal fluid, urine via SPA, wound exudate, blood
Needle Aspiration/Extraction
Done by aspirating from a catheter tube
Catheterization
Diagnostic Purpose of Blood Specimen
To determine bloodstream infection (bacteremia)
What can be determined during blood culture?
Presence of bacteria, not the toxin
Usual order of blood specimen
2 sets of blood culture (1 for aerobic bottle and 1 for anaerobic bottle)
Why do they order 2 sets of blood culture?
To distinguish TRUE pathogen