Giving a medicine or treatment to a healthy individual in order to prevent disease occurring.

‘the art and science of preventing disease, prolonging life and promoting health through the organized efforts of society’ (Winslow, C.-E. A. (1920) ‘The untilled fields of public health’, Science, vol. 51, no. 1306, pp. 23–33).

The process by which bacteria communicate with each other. It allows bacteria to share information about cell density and change their behaviour accordingly. For example, at high cell density, Vibrio fischeri bacteria alter their behaviour to emit fluorescent light. At low cell density, the bacteria are not fluorescent.

Medical diagnostic test that is quick and provides a rapid read-out that can be used to diagnose the patient.

Chemically reactive chemical compounds containing oxygen, for example hydrogen peroxide (H2O2). They can damage DNA and proteins.

The synthesis of an exact copy of a DNA molecule.

Drugs that do not kill bacteria themselves but, when co-administered with a failing antibiotic, can overcome resistance.

A structure in the cell where proteins are made. Each ribosome consists of a large and a small subunit which have distinct roles in protein synthesis.