LO4 Flashcards
the most common test requested from the Microbiology Lab is the
culture and sensitivity
what is a pure culture
when you isolate a colony, when there is a mix sample you streack it and get a single colony and pick just that type of colony then you know its all one organism and you go on to subculture is inot new media so othr work can be doen on it to identify it
the planting process
applying an inoculum and then streaking it in order to get single colonies to make it easier to identify
where do you store specimens that can not be processes right after collection
exception
refrigeration
CSF exception it needs room temp or short term 37C, this is bc the bacteria causing meningitis can die in colt
alternative to refrigeration
transport media : only works for some
Amies or Stuart transport media in swab
containers
Carey-Blair fluid for stool culture
SAF fixative for stool parasite examination
what are some instances that require plating right as a culture is taken
gonorrhea, very fastidious, needs CO2 to survive
cervix/male urethra, swap rolled on plate, tablet generates CO2 when moisture present and placed into a plastic bag
specimen pretreatment: Fluids
Sterile body fluids: cerebrospinal, pleural, synovial,
peritoneal and pericardial fluids
usually do not have many organisms so we must concentrate by:
-Centrifuging : supernatant put away into a sterile tube, the sediment is resuspended and then planted
-filtering
-cytocentrifuging :concentrates small amount of fluid onto a slide
synovial/ joint is very viscous when you concentrate it will make it thick and it will wash off in the gram stain and then if the swab is from an abscenss we would not concentrate it either bc there is already lots thre
pretreatment: Tissue
excpetions and notes
-grind them to release the microbe
-the fluid with a but of tissue is picked up by pipette and inoculated
-gram stain is done bf the grinding
-tissue with fungal cultures ordered are not grind and just sliced inot small pieces
pretreatments =: fluids with clots
the clot is the one that has the organism
centirfuge
remove clot
palced inot broth or saline and ground
pretreatment: sputum
remove the mucous using a mucolytic agent
mixed in for planting
Biological safety cabinet
protects from inhalation of aerosols
all planting is done inside of it
some talks about tools pgs 67-69
inoculation
swab
liquid
semi-solid
swab: roll on each side onto a slide and then into the well of the plate
aways inoculate fluid media last
if its in a broth wrung it out
liquid: dropped onto a slide, and on a plate, 1 drop
semi-solid: swab/ loop
order of inoculation
sterile microscope slide: gram stain
plating-
enriched media
least selective media
most selective media
liquid culture media
aseptic tech
The processes and procedures utilized to keep cultures free from outside contamination
