Quorum sensing is a communication system within a single bacterial species or between diverse species, which enables the microbes to survive and multiply. It enables the bacteria in a closed system, such as a biofilm, to adapt to local conditions within the community and to avoid the immune response of the host and/or chemical and antibiotic attack.
Quorum sensing enables bacteria to coordinate their behavior. As environmental conditions often change rapidly, bacteria need to respond quickly in order to survive. These responses include adaptation to availability of nutrients, defense against other microorganisms which may compete for the same nutrients, and the avoidance of toxic compounds potentially dangerous for the bacteria. It is very important for pathogenic bacteria, during infection of a host (e.g. humans, other animals, or plants), to coordinate their virulence to escape the immune response of the host and be able to establish a successful infection.
Bacteria use quorum sensing to coordinate certain behaviors based on the local density of the bacterial population. Quorum sensing can occur within a single bacterial species, as well as between diverse species, and can regulate a host of different processes, in essence, serving as a simple communication network.
