PSA 4 - Kirby-Bauer Method

What is the primary purpose of the Kirby-Bauer test?

• To identify bacterial species

• To measure bacterial growth rate

• To assess bacterial morphology

• To determine bacterial susceptibility to antibiotics

What does a clear zone around an antibiotic disc indicate?

• Bacterial growth

• Contamination

• Bacterial inhibition

• Bacterial resistance

What does a large zone of inhibition suggest about the bacteria?

• High resistance to the antibiotic

• Susceptibility to the antibiotic

• No effect of the antibiotic

• The antibiotic is expired

Which factor can affect the accuracy of the Kirby-Bauer test?

• Incubation temperature

• Agar thickness

• Inoculum density

• All of the above

At what temperature is the Kirby-Bauer test incubated?

• 25

• 30

• 35

• 40

How is the zone of inhibition measured?

• Using a ruler across the diameter

• Counting the number of colonies

• Weighing the bacterial mass

• By estimating visually

Match the interpretation to the clinical implication:

1. Antibiotic likely effective in treatment​ (a)   ​

Possible effectiveness; may require higher dose​ (b)  

Antibiotic unlikely to be effective​ (c)  

No zone of inhibition​ (d)  

• Susceptible
• Intermediate
• Resistant
• Complete Resistance