Editing Quorum sensing (section)

====''Pseudomonas aeruginosa''====
The environmental bacterium and opportunistic pathogen ''[[Pseudomonas aeruginosa]]'' uses quorum sensing to coordinate the formation of [[biofilm]], [[swarming motility]], [[exopolysaccharide]] production, virulence, and cell aggregation.<ref>{{cite journal | vauthors = Sauer K, Camper AK, Ehrlich GD, Costerton JW, Davies DG | title = Pseudomonas aeruginosa displays multiple phenotypes during development as a biofilm | journal = Journal of Bacteriology | volume = 184 | issue = 4 | pages = 1140–1154 | date = February 2002 | pmid = 11807075 | pmc = 134825 | doi = 10.1128/jb.184.4.1140-1154.2002 }}</ref> These bacteria can grow within a host without harming it until they reach a threshold concentration. Then they become aggressive, developing to the point at which their numbers are sufficient to overcome the host's [[immune system]], and form a [[biofilm]], leading to [[disease]] within the host as the biofilm is a protective layer encasing the bacterial population.{{citation needed|date=July 2022}} The relative ease of growth, handling, and genetic manipulation of ''P. aeruginosa'' has lent much research effort to the quorum sensing circuits of this relatively common bacterium. Quorum sensing in ''P. aeruginosa'' typically encompasses two complete AHL synthase-receptor circuits, LasI-LasR and RhlI-RhlR, as well as the orphan receptor-regulator QscR, which is also activated by the LasI-generated signal.<ref>{{cite journal |last1=Schuster |first1=Martin |last2=Peter Greenberg |first2=E. |title=A network of networks: Quorum-sensing gene regulation in Pseudomonas aeruginosa |journal=International Journal of Medical Microbiology |date=April 2006 |volume=296 |issue=2–3 |pages=73–81 |doi=10.1016/j.ijmm.2006.01.036 |pmid=16476569 }}</ref> Together, the multiple AHL quorum sensing circuits of ''P. aeruginosa'' influence regulation of hundreds of genes.

Another form of [[gene regulation]] that allows the [[bacteria]] to rapidly adapt to surrounding changes is through environmental signaling. Recent studies have discovered that [[anaerobiosis]] can significantly impact the major regulatory circuit of quorum sensing. This important link between quorum sensing and anaerobiosis has a significant impact on the production of virulence factors of this [[organism]].<ref name="Cornelis">{{cite book |editor=Cornelis, P. |title=Pseudomonas: Genomics and Molecular Biology |url= http://www.horizonpress.com/pseudo |edition=1st |year=2008 |publisher=Caister Academic Press |isbn=978-1-904455-19-6 |access-date=1 May 2022}}</ref> There is hope among some humans that the therapeutic enzymatic degradation of the signaling molecules will be possible when treating illness caused by biofilms, and prevent the formation of such biofilms and possibly weaken established biofilms. Disrupting the signaling process in this way is called ''quorum sensing inhibition''.<ref>{{cite journal |last1=Ma |first1=Yeping |last2=Tang |first2=Wing Suet |last3=Liu |first3=Sylvia Yang |last4=Khoo |first4=Bee Luan |last5=Chua |first5=Song Lin |title=Juglone as a Natural Quorum Sensing Inhibitor against Pseudomonas aeruginosa pqs-Mediated Virulence and Biofilms |journal=ACS Pharmacology & Translational Science |date=9 February 2024 |volume=7 |issue=2 |pages=533–543 |doi=10.1021/acsptsci.3c00354 |pmid=38357290 |pmc=10863437 }}</ref>