Quorum Sensing

Key Systems#

AHL (N-acyl homoserine lactones): Gram-negative QS signals (LuxI/LuxR system). Used by Pseudomonas aeruginosa, Vibrio, Burkholderia. AI-2 (Autoinducer-2): Universal interspecies signal (LuxS-dependent).

Enables cross-species communication within polymicrobial biofilms. Farnesol: C. albicans QS molecule that inhibits yeast-to-hyphal transition—but can be overridden by bacterial signals in Functional Shielding contexts.

WikiBiome Relevance#

Biofilm virulence: QS coordinates the transition from planktonic growth to biofilm mode, enabling Functional Shielding and antibiotic resistance.

Anti-QS interventions: Quorum quenching—disrupting QS signaling—is a non-antibiotic strategy to attenuate virulence without killing bacteria (avoiding resistance selection). Ethiopian medicinal plants show anti-QS activity;^{[1]Bacha 2016 — Antimicrobial and Anti-Quorum Sensing Activities of Ethiopian Medicinal PlantsKetema Bacha, Yinebeb Tariku, Fisseha Gebreyesus et al. · 2016Open reference 1 ↓} thymoquinone from Nigella sativa disrupts QS.^{[2]Rahman 2024 — Nigella sativa extract: phytochemical analysis and antimicrobial/antioxidant activityAnees Ur Rahman, Abdullah Abdullah, Shah Faisal et al. · 2024Open reference 2 ↓}

NEC: QS-regulated virulence in NEC-associated pathogens.^{[3]Devarajalu 2025 — Gut microbiota signatures in Indian preterm infants with NEC: shotgun metagenomic approachPrabavathi Devarajalu, Savita Verma Attri, Jogender Kumar et al. · 2025Open reference 3 ↓} Interkingdom: Fungal-bacterial QS cross-talk modulates polymicrobial biofilm dynamics.^{[4]The mycobiome in human cancer: analytical challenges, molecular mechanisms, and therapeutic implicationsTing Ding, Chang Liu, Zhengyu Li · 2025Open reference 4 ↓}