Susceptibility Testing is a laboratory method used to determine how effective specific antibiotics or antimicrobial agents are against bacteria or fungi. This testing helps healthcare providers choose the most appropriate treatment for infections by identifying which drugs can inhibit or kill the pathogens. The process typically involves growing the microorganism in the presence of various concentrations of antibiotics. The results indicate whether the organism is susceptible, intermediate, or resistant to each drug tested. This information is crucial for guiding treatment decisions and combating antibiotic resistance effectively.