Final answer:
The Kirby-Bauer test is used to determine the susceptibility of a microorganism to an antimicrobial by measuring zones of inhibition around disks impregnated with antimicrobials placed on an inoculated agar plate.
Step-by-step explanation:
The test used to determine the susceptibility of a microorganism to an antimicrobial is the Kirby-Bauer test, also known as the disk diffusion test. This test involves placing disks impregnated with antimicrobial agents onto an agar plate that has been inoculated with the microorganism in question.
The zones of inhibition, or areas where microbial growth is prevented around the disks, are measured to determine susceptibility. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) are also methods used to determine antimicrobial susceptibility, but these are not the same as the Kirby-Bauer test. The Etest combines elements of both disk diffusion and dilution methods to determine MIC.