Podcast
Questions and Answers
What is the purpose of the Kirby-Bauer disk diffusion test?
What is the purpose of the Kirby-Bauer disk diffusion test?
- To determine the size of bacterial pathogens
- To study the growth patterns of bacteria
- To isolate bacterial pathogens from patients
- To test the susceptibility of microbes to antimicrobial drugs (correct)
What is placed on the agar plate during the Kirby-Bauer assay?
What is placed on the agar plate during the Kirby-Bauer assay?
- Filter paper disks impregnated with antibiotics (correct)
- Petri dishes for incubation
- Chemical solutions for staining
- Bacterial pathogen samples
How is antibacterial activity observed in the Kirby-Bauer disk diffusion test?
How is antibacterial activity observed in the Kirby-Bauer disk diffusion test?
- By observing color changes in the agar
- By measuring the growth rate of bacteria
- By noting the presence of a clear circular zone of inhibition (correct)
- By counting the number of filter paper disks
Why does the interpretation of the Kirby-Bauer assay provide only limited information on susceptibility and resistance?
Why does the interpretation of the Kirby-Bauer assay provide only limited information on susceptibility and resistance?
Why can differences in zone sizes not be used to compare drug potencies or efficacies in the Kirby-Bauer test?
Why can differences in zone sizes not be used to compare drug potencies or efficacies in the Kirby-Bauer test?
Study Notes
Kirby-Bauer Disk Diffusion Test
- A method for determining the susceptibility of specific microbes to various antimicrobial drugs.
- The test starts with a confluent lawn inoculated with a patient's isolated bacterial pathogen.
Assay Procedure
- Filter paper disks impregnated with known amounts of antibacterial drugs are placed on the agar plate.
- Antibiotic diffuses from the circular disk into the agar and interacts with the growing bacteria.
Zone of Inhibition
- Antibacterial activity is observed as a clear circular zone of inhibition.
- The diameter of the zone of inhibition helps determine the susceptibility or resistance of the bacterial pathogen to a particular drug.
Factors Affecting Zone of Inhibition
- Drug solubility
- Rate of drug diffusion through agar
- Thickness of the agar medium
- Drug concentration impregnated into the disk
Limitations of the Assay
- Lack of standardization of the factors mentioned above.
- Provides only limited information on susceptibility and resistance to the drugs tested.
- Cannot distinguish between bacteriostatic and bactericidal activities.
- Differences in zone sizes cannot be used to compare drug potencies or efficacies.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
Learn about the Kirby-Bauer disk diffusion test, a method used to determine the susceptibility of microbes to antimicrobial drugs. This quiz covers the procedure of the test, including the inoculation of bacterial pathogens and the placement of antibiotic-impregnated disks on agar plates.
