diskdiffusietesten

Disk diffusion testing is a microbiological laboratory technique used to determine the susceptibility of bacteria or fungi to antimicrobial agents. It is a qualitative or semi-quantitative method that provides a visual assessment of inhibition zones around discs impregnated with specific concentrations of an antibiotic or antifungal drug.

The procedure involves inoculating a standardized lawn of the microorganism onto an agar plate. Sterile paper discs, each containing a known amount of a particular antimicrobial agent, are then placed onto the surface of the inoculated agar. The plate is subsequently incubated under controlled conditions, allowing the microorganism to grow and the antimicrobial agent to diffuse from the discs into the agar.

During incubation, if the microorganism is susceptible to the antimicrobial agent, it will be inhibited from growing in the vicinity of the disc. This results in a clear zone of inhibition surrounding the disc. The size of this zone is inversely proportional to the microorganism's resistance to the agent. Larger zones indicate greater susceptibility, while smaller or absent zones suggest resistance.

The results are typically interpreted by comparing the diameter of the inhibition zone to established breakpoints, which are defined by regulatory bodies. These breakpoints classify the microorganism as susceptible, intermediate, or resistant to the tested antimicrobial. Disk diffusion testing is a widely used, cost-effective, and relatively simple method for guiding antimicrobial therapy and monitoring resistance patterns in clinical and research settings.