Bacteria communicate by means of chemical signals and can develop common characteristics through this "agreement" and also develop their potential pathogenic effects in this way.

The investigation of bacterial communication is also of medical interest. This is because the bacterial communication pathways are a possible therapeutic target for new medicines. If the relevant communication options are prevented, the bacteria cannot develop their pathogenic properties. When pathogens are no longer destroyed by antibiotics as we have seen to date, but rather be impaired beforehand the formation of the pathogenic properties, the danger of resistance development would be substantially reduced. To date, the best known communication between bacteria occurs via the N-acyl homoserine lactone (AHL): The enzyme Luxl produces signals that are recognised by the LuxR receptor, at which point the bacteria develop certain properties and modulate their behaviour towards one another. Since a certain number of bacteria must be available for this to occur, this process is known as "quorum sensing."