Lab: Antibiotic Sensitivity: Agar Disc Diffusion Flashcards
(17 cards)
What is the disk diffusion method also known as?
Kirby-Bauer method
What does the disk diffusion method determine?
The sensitivity of bacteria to various concentrations of different antibiotics
Why do different bacterial species respond differently to antibiotics?
Because the mode of action for many antibiotics differs
What should you be able to determine after completing the antibiotic sensitivity exercise?
The sensitivity of various bacteria to different antibiotics
True or False: The largest zone of inhibition always indicates the ‘best’ antibiotic.
False
What is the first step in the procedure for Day One?
Using a sterile swab, inoculate the agar plate with one of the available bacteria
What should be done with the swab after inoculating the agar plate?
Dispose of it in the red biohazard bag on the kill cart
How should forceps be sterilized?
By passing them through the flame of the Bunsen burner after removing them from alcohol
How many different antibiotic disks should be placed on the agar surface?
Five different antibiotic disks
What should be recorded when using antibiotic disks?
The full antibiotic names, abbreviations, and concentrations
At what temperature should the plates be incubated?
37°C
What should be done on Day Two after incubating the plates?
Examine the clearing around the disks
What is used to measure the zone of inhibition diameter around each disk?
A small ruler
What should be created in the laboratory notebook to display results?
A chart displaying the results for all bacteria available
What type of conclusions should be included in the laboratory notebook?
Conclusions explaining how to determine the zone of inhibition and correlations between antibiotic effectiveness and gram positive or gram negative bacteria
How can you determine which bacteria used were gram positive and gram negative?
By discussing any correlations found between antibiotic effectiveness and gram positive or gram negative bacteria
Fill in the blank: The method used to determine the sensitivity of bacteria to antibiotics is the _______.
disk diffusion method
