Which method is used to determine antibiotic susceptibility in bacteria?

Antibiotic susceptibility testing is the method specifically designed to determine how effective different antibiotics are against particular bacterial strains. This testing helps healthcare professionals decide the best treatment for bacterial infections by identifying which antibiotics kill the bacteria or inhibit their growth.

Methods commonly employed in antibiotic susceptibility testing include disk diffusion (Kirby-Bauer method), broth dilution, and automated systems that measure the minimum inhibitory concentration (MIC) of antibiotics. The results from these tests guide clinicians in prescribing the most effective antibiotic, ultimately improving patient outcomes and combating antibiotic resistance.

The other options listed are not suitable for determining antibiotic susceptibility. Polymerase chain reaction (PCR) is a technique used to amplify DNA sequences and is primarily used for diagnosis and detecting the presence of specific organisms. X-ray imaging is a diagnostic tool employed to visualize internal structures of the body, not to assess bacterial susceptibility. Serological testing is used to detect antibodies or antigens in the blood and doesn’t provide information on antibiotic effectiveness against bacteria.