Clinical Microbio. lab Flashcards
Once an organism has been isolated & reported which info. is most significant to doctors?
susceptibility profile over ID of microbe (find treatment)
List 2 situations where accurate identification is important.
- Overt pathogens always require accurate speciation
2. ID required to ongoing & recurrent infections
What’s the relationship b/w specimen quality & time interval b/w collection & processing?
Specimen quality decrease with time = NF overgrowth OR microbes not survive bc in unfavourable cond. (die b4 test) => hard to isolate/identify pathogen
What’s the ideal max. time elapsed b/w collection & processing?
specimens received w/in 2 hrs
2+ advantages of placing swab in transport media (4)
- preserves bact. w/out multiplying
- prevent drying out bc semisolid agar
- maintains pH
- reducing a. = remove O2 for anaerobes
2+ specimens that have Hi priority (4)
- CSF
- tissue
- blood cultures
- sterile fluids
What’s the significance of seeing Polymorphonuclear WBC (PMN cells) in a wet prep. or stained smear?
means there’s and infection
What does large smaple of epithelial cells in sputum or urine sample indicate?
indicate likely contamination w/ NF
Why are CHOC plates always incubated in CO2?
to accomodate Haemophilius & Neissaria
List 4+ reasons a specimen maybe rejected (7)
- Unlabelled
- Illegible handwriting on label
- Mismatched details on transport media & paperwork
- Insufficient material or leaking specimens
- Specimens not processed for a long time
- Inappropriate specimen collected for test
- Specimen collected in formalin (mistaken for saline)
4 guidelines for ensuring a good quality microbio. specimen
- Correct & clear labelling of ALL specimen collected
- Collect directly from site of infection (prevent contamination w/ NF)
- Sufficient quantity of sample to perform all tests
- Sterile containers (except for feaces)
