Concept
Quorum sensing
Cell-density chemical communication
KWOR-um SEN-sing
High-yield clue
Quorum sensing lets bacteria track their population density via autoinducers and switch on group behaviors like biofilm and virulence.
Overview
A cell-to-cell communication system in which bacteria secrete and detect signaling molecules (autoinducers) to sense population density and coordinate group behaviors. It regulates biofilm formation and virulence-factor expression.
Classification
- Cell-density signaling
- Autoinducer molecules
- Coordinated gene expression
- Population-level behavior
Lab & identification clues
- Acyl-homoserine-lactone (AHL) vocabulary
- LuxI/LuxR system concept
- Autoinducer-2 (AI-2) vocabulary
Associations
- Biofilm-formation coordination
- Virulence-factor timing
- Prominent in Pseudomonas study
Commonly confused with
- Lac operon regulation
- Two-component systems
Your notes
Original microbiology concept summary. Sources checked: OpenStax Microbiology 2e, NCBI Bookshelf Medical Microbiology, and CDC/WHO topic pages where applicable; reviewed 2026-06. Educational only; no diagnosis, treatment selection, infection-control instructions, or specimen-handling guidance.