Garlanda 1 Flashcards
(53 cards)
How can labs id organisms
directly (microscopically, culture, genome)
indirectly (finding antibodies to that organism)
What are the 5 types of lab tests
microscopy culture immunologic tests nucleic acid based ID non nuclei acid based ID
The 5 I’s of sample processing
inoculation incubation isolation inspection identification
What word is most important in inoculation
medium
define culture
the visible growth of the microbe in or on the medium
what is the gold standard for ID
culture
in the isolation stage what are the microbes in
colonies on solid media, or turbidity (free floating cells) in broths. Note subculturing occurs here
How do non nucleic acid tests (NNAT) work
they use phenotypic (functional or morphologic) characteristics
tests are done in what order
sequentially, which the results of the last one helping guide the next one
for lesions where should you sample
the leading edge
fill in the collection method for the following locations skin, membrane blood CSF stomach urine lungs diseased tissue
sterile swab (NYLON) needle aspiration from vein needle aspiration from subarachnoid space intubation catheter with midstream urine sputum surgical removal biopsy
contamination of urine sample
all non surgical samples become contaminated with urogenital flora during collection. these bacteria witll replicate if the specimen is not quickly stored in a preservation tube at 4C
when should you collect samples for blood parasite infections
during a febrile episode or every 6 hours for a 24 hour period
Quantity of CSF culture needed
2 ml from tubes 2, 3, or 4
For anaerobic culture what are 3 considerations
- you should not obtain sample from areas where normal flora is present
- fluid specimens (abscess) are superior to swab specimens
- transport fluid in a syringe or an anaerobic transport vial
- are best collected with metal (needle aspiration or scapel)
T/F a large piece of tissue (5-10 mm) willl protect anareobes in the center
T
How to collect chlamydia/N. gonorrhea culture
chlamydia in universal transport medium, GC culture in amies and charcoal or tranport to lab for immediate plating
is culture an option for tissue sent in formalin
no
is bacterial culture possible in sent in viral transport media
no, most VTM contain antibiotics
when to test for microbiology
before giving antibiotics
Levels of biosafety and examples
BSL 1: non pathogenic for healthy ppl. Use soap/disinfectants E.g: non pathogenic E.coli
BSL 2: moderately hazardous. Use safety cabinets. E.g MRSA, heptatitis
BSL 3: use cabinets, rooms with HEPA filters, double doors. E.g. TB, B antracis, yellow fever, SARS/COV2
BSL 4: fatal dx E.g. ebola, smallpox, lassa fever viruses. Use separate building, airlocks, showers, vacuum. Filter air and water
HEPA (high efficiency particulate air) filters can be placed on
safety cabinets, operating rooms, rooms of infected or immunocompromised pts
When do you need microscopic examination of tissue in a culture
to distinguish invasive disease from surface colonisation
Visibility of fungi can be improved by
applying 10% KOH to dissolve surrounding skin tissue and non fungal organisms so that you only have the fungus left, and its easier to observe
