Culture and sensitivity

Paper disks containing various antibiotic drugs are placed on a culture plate. The plate contains a growth medium that has been swabbed with a specimen from the patient (mucus, pleural fluid, etc.). If the bacteria in the specimen are resistant to that antibiotic drug, there will only be a small zone of inhibition (no growth) around that disk. If the bacteria are sensitive to that antibiotic drug, there will be a medium or large zone of inhibition around that disk, and the physician may prescribe that drug to treat the patient’s infection.