What is the zone of inhibition?

The zone of inhibition refers to the area surrounding a chemical disc, often containing an antibiotic or antibacterial agent, where bacteria are unable to grow. This phenomenon is observed during susceptibility testing, where a microbial culture is exposed to different antimicrobial agents. When the bacteria are sensitive to the agent, it cannot grow in this zone due to the effects of the chemical that inhibits or kills the bacteria.

This measurement is crucial for determining the effectiveness of antibiotics and helps in guiding treatment options for infections. The size of the zone can provide insights into the susceptibility of the bacteria to the antimicrobial agent tested. Understanding the concept of the zone of inhibition is important for evaluating antibiotic efficacy, rather than simply describing areas of growth or conditions conducive to bacterial proliferation.