Quorum sensing is best characterized as a means of communication within a bacterial species, whereas competitive or cooperative signaling can occur between groups of bacteria or between bacteria and the host ( Gram-Negative bacteria,Gram-Positive bacteria and Biofilm).
Quorum sensing can be divided into at least 4 steps:
(1) production of small biochemical signal molecules by the bacterial cell; (2) release of the signal molecules, either actively or passively,into the surrounding environment; and (3) recognition of the signal molecules by specific receptors once they exceed a threshold concentration, leading to (4) changes in gene regulation.
One common consequence of quorum sensing induction of gene expression is increased synthesis of the proteins involved in signal molecule production. Increased synthesis of the signal molecule creates a positive feedback loop, which is why quorum signals are commonly called autoinducers.
From:
Bench-to-bedside review: Quorum sensing and the role of
cell to cell communication during invasive bacterial infection
