Dilution method Flashcards
How many mL for macrodilution test?
1mL broth
How many mL for microdilution test?
0.05mL to 0.1mL
For microorganisms with unpredictable susceptibilities
Minimum inhibitory concentration
NOTE: MIC is the first broth in which the growth of the organisms has been inhibited
EX: (CLick again)
1st tube (10mg): No growth
2nd tube (20mg): No growth
3rd tube (30 mg): Growth
The more resistant an organism, the ______ will be the MIC. (Higher/Lower)
Higher
Set up for Macrobroth?
MHB + Antibiotics + Inoculums of uniform volume (Same volume)
Antibiotics are NOT uniformed but?
Serially diluted
This system uses a tray that would contain the antibiotics
Alamar system
What is the indicator for Alamar system?
Alamar Blue indicator
Set up of alamar system?
MHB + ORganism + Alamar blue indicator
What is the indicator when there is growth?
Blue to pink
PINK
What is used in microdilution?
Microtiter plate
Uses automated multi-pronged inoculators calibrated to deliver the precise volume of inoculum to each well
Microdilution
What is the temp for the storage in microdilution?
- 20C
Once thawed, the panels should never be refrozen because of substantial loss of antimicrobial action and potency? T or F
TRUE
Instead of freezing microdilution, what is the alternative for this?
Lyophilization
Detect growth in micro volumes of broth with various dilutions of antimicrobials
Detection via photo, turbid, or fluorometric methods
Automated AST methods
Automated AST methods machines?
BD phoenix
Microscan walkaway
TREK sensititre
Vitek 1 and 2
What are the advantages of Automated AST methods?
Increased reproductivity
Decreased labor cost
Rapid
Software
Detects multi-drug resistance
ESBLs
Correlates bacterial ID and sensitivity
What is the only disadvantage of Automated AST methods?
Cost
